JPS6156950A - Moisture sensitive device - Google Patents

Abstract

PURPOSE:To perform accurate humidity detection, by forming a moisture sensitive element by a moisture sensitive part and lead terminals provided at the moisture sensitive part, supporting lead wires by a case, which encloses the moisture sensitive element, and constituting the outer surface of the moisture sensitive part and the inner wall of the case so that they are not contacted. CONSTITUTION:A moisture sensitive element 30 is formed by a moisture sensitive part 301 and lead terminals 302 and 303. The element 30 is supported by a case 1 so that the outer surface of the moisture sensitive part 301 is not contacted with the case. A case 100 is formed on the right and left sides of a hinge part 103 and a sensor 10 is housed in the box shaped case 100 having an opening 101. The moisture sensitive element 30 is positioned in a space formed by the boxes. The moisture sensitive surface is positioned so as to face the opposite surface with respect to the opening 101. The lead terminals 302 and 303 of the moisture sensitive element 30 are connected to lead wires 50. They are held by a taking-out groove 109 and a lead pushing projection 111. Thus useless operation is eliminated and automatic stopping function can be imparted.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] □ The present invention relates to a humidity sensor, and particularly to a humidity sensor that is placed in the ventilation path of a clothes dryer to detect the humidity. This article relates to a humidity sensor that uses a means to improve environmental resistance when used in adverse environments where it tends to adhere.

[Background of the invention]

Conventionally, this type of humidity sensor has been used in measuring instruments, etc.9, air conditioning equipment in warehouses, etc., and has sacrificed its ability to follow humidity changes by using a dust-proof filter. In a humidity sensor that uses dust as a humidity sensitive agent, a heater is placed nearby and the heater is energized every predetermined time period to burn off the dust and prevent it from deteriorating. These devices are complicated and expensive, and the heater energization method requires electric power, making the electronic circuit difficult.

[Purpose of the invention]

The present invention, like a clothes dryer, humidifies and dehumidifies to a large extent and may be very rapid. In addition, even though the dryer has a filter, in order to install it in a place where fine lint and dust from clothes pass through, and to accurately detect humidity, we use a general-purpose humidity sensor and store the sensor in a case. However, this case protects it from dust.

[Summary of the invention]

In the present invention, a humidity sensing element is formed from a humidity sensing part and a lead terminal provided in the humidity sensing part, the lead terminal is supported by a case surrounding the humidity sensing element, and the outer periphery of the humidity sensing part and the inner wall of the case are brought into contact with each other. It is characterized by having the following configuration.

11 An embodiment of the present invention will be described below with reference to FIGS. 1 to 9. FIG. 1 is a diagram showing the configuration of a clothes dryer, and FIG. 2 is a partially detailed diagram. To explain the structure, 1 is an outer frame, 19 is a back lid, and 22 is a door for the clothing official. The drum 2 is rotatably supported within a frame formed by these components, and is rotated by a drive motor 14 and a drum belt 15. 16 is motor 1
A pulley located on the opposite side of the drum belt 15 of No. 4,
Engage the fan belt 17. The fan belt 17 is engaged with a fan pulley 7B formed around the shaft, and drives the double-winged fan 7. 20 is a shaft support. 8 is a fan casing for this double-winged fan 7, which is attached to the back of the drum 2 (
The felt receiver guides the air from the air passage hole 4 (on the opposite side of the door 22) and is connected to the central duct 6 on the lower surface of the drum. 13 and the felt 9 are configured to be kept substantially airtight. 11 is drum airtight felt for drum 2
and the fan casing 8. 18 is
1 heater side duct, 3 a heater serving as a heat source, 23 an operator, 24 clothing, 25 an outside air introduction hole, 10
101 is a sensor, 101 is an opening provided on the windward side through which air passes, 102 is a mounting leg, and 103 is a lead wire for signal transmission.

To explain the operation based on these schematic configurations, motor 1
The drum 2 and the double-winged fan 7 are driven by the fan 4.

The drum 2 stirs the clothes 24 to be dried, and the double-winged fan 7 uses the fan on the side of the drum 2 to pull the air inside the drum 2, and while rectifying it on the way, it passes through the central duct 6 and the heater duct 18 and is heated. It also passes through step 3 and is heated. The heated air passes through the clothing 24, separates moisture, becomes humid, and returns to the passage hole 4. Further, the fan on the back cover 19 side pulls outside air through the outside air introduction hole 25, and exhausts the outside air through the upper part. Therefore, the air on the drum z side, which is humid and relatively high in temperature, is cooled in the outside air and condensed into water droplets.
The heat is collected in the central duct 6, and is constructed as a heat exchanger using both wings. The sensor 10 is placed in the perm mouth 5 of the fan casing 8, at a location before it is introduced to the passage hole 4 of the drum 2 and the fan 7, in order to be exposed to humid and relatively high temperature air before being compressed. It depends on the location. The dotted line labeled F in the figure is a filter. This filter captures dust such as lint and sand from clothing, and ideally the sensor would immediately capture the air that has passed through this filter. This is because the closer you get to the two-wing fans, the lower the air temperature is, and the more air is mixed with air that has been compressed through heat exchange and lowered humidity, making it impossible to accurately measure the humidity of clothing. It is.

Next, the sensor 10 alone will be explained in detail. FIG. 3 is a diagram of the sensor 10 alone, FIG. 4 is a perspective view of the sensor case, and FIGS. 5 to 7 are explanatory diagrams of the moisture sensing element alone. From these, the sensor 10 is housed in the sensor case 100, and the sensor case 100 formed on the left and right sides at the hinge part 103 is box-shaped with an opening 101.
The lid 104 facing this box-like shape is the sensor case 1
By using the hinge part 103, which has a shallow box shape similar to 00, as a fulcrum and engages with the engagement claw 112 and the engagement hole 108, a box-like space is created. The humidity sensing element 101 is placed in this space, and the humidity sensing element 10
The lead storage groove 109 holds the signal transmission leads 302 and 303 pulled out from the lead wire 5 , and the lead holding protrusion 111 holds the leads 302 and 303 .
A round terminal housing groove 109 for storing a round terminal 40 for electrical connection with the round terminal 40, a round terminal relief 114, and a caulked lead wire 50 are pulled out through the groove of the bent portion 110 and the lead wire guiding groove 115. 107 is the sensor 1 that is kept in high humidity.
Since it is 0, if there is a leak between the terminals due to condensation, etc., it will malfunction. Leak prevention protrusions are provided to prevent this danger.
Reference numeral 113 denotes a corresponding protrusion retaining groove, which ensures the distance between the terminals. 106 is a lead wire holder.

As described above, the humidity sensing element 30 has leads 302 and 303.
, the lead storage groove 109 and the lead presser protrusion.
They are held at 111 and are overlapped with each other using the hinge portion 103 as a fulcrum, and are locked by the engagement claw 112 and the engagement hole 108. ) Both end surfaces of the round terminal 40 are
Since it comes into contact with both walls of the round terminal accommodating portion 105 and absorbs it, the structure is such that the leads 302 and 303 and the moisture sensing element 30 are not affected at all.

To explain the humidity sensing element 30 in detail, a comb-shaped electrode A306. There is an electrode B505. Lead 302.303 and electrode A30
6. The electrode B 305 is connected using solder 307. Between the comb-shaped opposing electrodes, there is a
If a moisture sensitive agent 308 (polymer solute) whose conductivity changes depending on humidity changes is applied, and the moisture sensitive agent has leaked out, dust from the outside, especially conductive substances such as bases, may adhere. A protective film 310 is applied to prevent the desired characteristics from changing. However, this protective film must not be airtight because it is a sensor that is sensitive to the humidity of the outside air. Materials such as silicone, which are highly permeable to water molecules, are used, but they are sensitive to external forces.

It is easy to peel off, and for this purpose, it is necessary to position it in the box-shaped space of the sensor case 100 without touching the inner wall.

Furthermore, the moisture sensitive surface 310 is positioned with its opposite surface facing the opening 101. This has a filter that traps dust, but not all of it, but allows fine dust, especially sand, to pass through. If the filter is not of this quality, the drying efficiency will deteriorate significantly. This is because the air passes through the location where the sensor 10 is located at a high speed, and dust should not damage the protective film and shorten the life of the sensor.

In addition to sensors consisting of an organic polymer moisture-sensing agent and a protective film, there are also sensors that use ceramics, which obtain moisture-sensing properties by coating a ceramic material on a comb-shaped electrode and then firing it. . A protective film such as silicone cannot be formed on this material. This is because ceramics after firing have a porous structure in the first place, and the degree of conductivity changes due to adsorption of water molecules, so the porous structure is closed. Also, ceramics are very weak against external forces, and their porous structure can be destroyed and their characteristics can easily deteriorate, so it is necessary to position them in a space with a structure like the sensor case 100. .

Looking at the humidity sensing element 30 from an electrical circuit perspective, as shown in FIG.
, 303. As shown in FIG. 8, the resistance value changes with respect to humidity changes, and as the humidity moves from low humidity to high humidity, the resistance value decreases almost proportionally.

Regarding these characteristics, we will explain how it works as a clothes dryer in Chapter 9.
10, the electric circuit shown in the block diagram includes a power supply circuit having a transformer and a rectifier, and a branched power supply circuit that is also connected to a motor and a heater. A processing circuit such as a microphone-based computer receives its driving source from the power supply circuit, and has various signal input circuits on the right side. 1
One has a humidity sensor at its tip, and goes through a detection circuit that converts and detects changes in electrical resistance, and a comparison circuit before entering the processing circuit.

The selection circuit is an input circuit that allows the user to arbitrarily select the degree of dryness.For example, if you want to iron the product while leaving it damp, use the "Iron Cycle", for general drying, use the "Standard Cycle", etc. If you want to dry with food in it, enter "cycycle with food" or the like. The display circuit is a circuit that displays these displays as well as the importance of power supply, etc.

Therefore, the input in the selection circuit drives the motor and heater and starts operation. When a signal is input from the humidity sensor during operation, the processing circuit opens the drive circuit and automatically stops the operation. Figure 10 shows the resistance value change of the humidity sensor during operation depending on the sensor shape and mounting position of the present invention, and is shown in three ways, A, B, and C. For example,
A is for a small amount, B is for a medium amount, and C is for a rated capacity as indicated. Products such as clothes dryers generally have these load fluctuations as a matter of course, and if they cannot cover all of these, the original automatic stop function will lose half its meaning.

Curve A indicates that there is less clothing, so the heated air passes through the heater 3.11) The heated air passes through the clothing, and the air goes through the filter to the double-winged fan 7 without touching the clothing, so the humidity is reduced. Since it does not drop much and dries quickly, the resistance value increases quickly, and the degree of increase in resistance value near the completion of drying is very large.

In the case of the rated capacity, the resistance value starts to decrease as soon as the operation starts, as shown by the curve shown in C, and after a certain period of time, the resistance value continues to decrease. As the clothes dry, the resistance value begins to rise, and although it becomes gentler than the human curve,
The degree of increase is more than sufficient for human power to send signals to comparison circuits, etc. B is drawn between A and C.

Now you can use the "Iron Cycle" and "Standard Cycle" mentioned above.
When we apply the "intrusion cycle", we find that the resistance value is R.
+ was defined as "iron cycle". This is the resistance value when a moderate amount of moisture remains, and is - near the point where it starts to rise rapidly. If you select "Iron cycle 1 cycle", the machine will automatically stop at (a). R2 was set as the "standard cycle". This is near the middle of the rise,
Automatic stop is performed at (b). “Eating cycle” is R
3, and the resistance value in a sufficiently dry state, ()7.
).

FIGS. 11 and 12 show an example of a conventional automatic stop means, which is operated by a temperature sensor 60.

Figure 12 shows the degree of temperature change, which shows that it rises at the start of operation, shows almost no change during the process, and then rises significantly near the completion of drying, similar to the change in resistance value of the humidity sensor mentioned above. , when completely dried, the curve becomes almost constant while rising. 1 in the resistance curve of the humidity sensor in Figure 10
Tr=T3 corresponds to ~R3.

The point of the curve that you want as a control signal is the point where it starts to rise.If you compare the humidity and temperature curves, the temperature curve is gentler and harder to detect. In particular, there is little difference between T2 and T13, making it difficult to distinguish between them. Furthermore, since a separate means to eliminate the influence of ambient temperature is required, the signal is extracted based on judgment at a wide range of temperatures, but it is not possible to operate with a margin of plus α after inputting the signal. is the current situation.

The present invention solves the above-mentioned problems and provides an automatic stop function that does not cause unnecessary operation.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the structure of the clothes dryer, and Figure 2 is a cross-sectional view showing the structure of the clothes dryer.
An enlarged view of the main parts of the figure, Figure 3 is a detailed sectional view of the sensor alone, Figure 4 is an open perspective view of the sensor case, Figure 5 is a perspective view of the moisture sensing element alone, and Figure 6 is the same as Figure 5. An enlarged view of the l-1f cross section, Fig. 7 is a diagram replaced with an electric circuit, Fig. 8 is a diagram showing changes in resistance value with respect to changes in relative humidity, Fig. 9 is a block diagram explaining the control of the clothes dryer, Fig. 10 Figure 11 shows the resistance change curve when the clothes dryer is operated.
This figure is a cross-sectional view similar to that shown in FIG. 1 using a temperature sensor which is an example of a conventional example, and FIG. 12 is a diagram showing changes in temperature corresponding to FIG. 10. 2...Drum, 7...Double wing fan, 10...Sensor, 30...Moisture sensing element, 100...Sensor case, 310...Protective film.

Claims (1)

[Claims] 1. In a humidity sensing device whose electrical resistance value changes according to changes in humidity, the humidity sensing element is formed from a humidity sensing part and a lead terminal provided in the humidity sensing part, and the humidity sensing element is wrapped. A moisture sensing device characterized in that a lead terminal is supported by a case, and the outer periphery of a humidity sensing part and the inner wall of the case are configured in a non-contact manner. 2. The moisture sensing device according to claim 1, characterized in that the case has an outside air introduction window formed therein. 3. A moisture-sensing device according to claim 2, characterized in that the moisture-sensing surface of the humidity-sensing section is on one side, and the non-humidity surface of the humidity-sensing section is on the outside air introduction window side of the case. . 4. In the device described in claim 1, a lead wire is connected to the lead terminal of the moisture sensitive element, a housing groove for pulling out the lead terminal and the lead wire is formed in the case, and the lead terminal and the lead wire are drawn out in the housing groove. A moisture-sensitive device characterized by holding a lead wire. 5. The moisture-sensitive device according to claim 4, characterized in that the case is divided into two parts, and a storage groove is formed on the mating surface of the case.