Method for manufacturing air conditioner

Abstract

To suppress odor generated from an air conditioner.SOLUTION: A method for manufacturing an air conditioner includes the steps of: flowing gas to a resin component 10 before it is assembled into an air conditioner, and acquiring a signal from a sensor 3 where a sensitive film 31 interacting with an odor substance containing a hydroxy group is arranged; and determining presence / absence of odor in the resin component 10 on the basis of the signal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing an air conditioner. [Background technology]

[0002] Japanese Patent Publication No. 2023-131154 (Patent Document 1) discloses a sensor for evaluating the quality of food during the manufacturing process. Japanese Patent Publication No. 2022-45689 (Patent Document 2) discloses an automatic detection device for oil and mold odors. International Publication No. 2021 / 200262 (Patent Document 3) discloses a sensor for evaluating the fermentation quality of silage, which is mainly used as cattle feed. The odor detection system disclosed in International Publication No. 2021 / 199893 (Patent Document 4) has a sensitive membrane that reacts to the substances that make up the gaseous odor for each substance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-131154 [Patent Document 2] Japanese Patent Application Publication No. 2022-45689 [Patent Document 3] International Publication No. 2021 / 200262 [Patent Document 4] International Publication No. 2021 / 199893 Summary of the Invention [Problem to be solved by the invention]

[0004] If an unpleasant odor occurs when an air conditioner is in use, the user may feel uncomfortable. The present disclosure has been made to solve the above problem, and one of the purposes of the present disclosure is to suppress the unpleasant odor that may be generated from an air conditioner. [Means for solving the problem]

[0005] A method for manufacturing an air conditioner according to one aspect of the present disclosure includes the steps of passing gas through a resin part before it is incorporated into an air conditioner, acquiring a signal from a sensor equipped with a sensitive membrane that interacts with odorous substances containing hydroxyl groups, and determining whether or not the resin part has an abnormal odor based on the signal. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to suppress unpleasant odors that may be emitted from air conditioners. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing the configuration of an off-odor determination system for a resin part according to a first embodiment; [Figure 2] 4 is a flowchart showing the processing steps of a method for manufacturing an air conditioner according to the first embodiment. [Figure 3] FIG. 10 is a diagram showing an example of the results of a sensory evaluation of odor intensity before and after heating when the resin part is a rubber part. [Figure 4] 10 is a time chart for explaining an example of a feature extraction method. [Figure 5] FIG. 10 is a diagram for explaining an example of an abnormal odor determination result obtained by principal component analysis. [Figure 6] FIG. 10 is a diagram showing the configuration of an off-odor determination system for a resin part according to a second embodiment. [Figure 7] 10 is a flowchart showing the processing steps of a method for manufacturing an air conditioner according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present inventors analyzed odorous substances emitted from resin parts before they are installed in air conditioners, and found that odorous substances containing hydroxyl groups contained in the resin parts are the main cause of the unpleasant odors that can occur in air conditioners.

[0009] To prevent the generation of unpleasant odors in air conditioners, it is desirable to evaluate the presence of unpleasant odors in resin parts before they are installed in the air conditioners during the manufacturing process. By installing resin parts that have been confirmed to have no unpleasant odors in the air conditioners, the generation of unpleasant odors from the air conditioners during use can be prevented.

[0010] A common method for determining whether a plastic part has an unpleasant odor is through sensory evaluation, which utilizes the human sense of smell. However, it is difficult to obtain objective (or quantitative) evaluation results through sensory evaluation. This is because the evaluation results depend on the preferences or senses of the panel (the person who smells and evaluates the odor), and the panel's sense of smell can fluctuate depending on their physical condition. It would be desirable to be able to objectively determine whether a plastic part has an unpleasant odor.

[0011] Gas chromatography is a well-known method for quantitatively evaluating odorous substances. However, gas chromatography requires large equipment and complicated procedures. Therefore, it is not practical to introduce gas chromatography into the manufacturing process of air conditioners. Therefore, it is desirable to be able to easily determine the abnormal odor of resin parts.

[0012] <Terminology> In the present disclosure and its embodiments, "air conditioner" may include room air conditioners, packaged air conditioners, indoor and outdoor units of housing air conditioners, ventilation fans, heat exchange ventilation equipment (Lossnay), and air purifiers.

[0013] In this disclosure and its embodiments, "resin parts" may primarily include rubber parts, housings, internal parts, filters, etc. Rubber parts may include nitrile rubber, isoprene rubber, butyl rubber, ethylene propylene rubber, chloroprene rubber, etc. Housings may include the outer panels and grilles of air conditioners made of materials such as ABS (acrylonitrile butadiene styrene) resin, PS (polystyrene) resin, PP (polypropylene) resin, and PET (polyethylene terephthalate) resin. Internal parts may include parts that make up fans, air ducts, and drain pans. Filters may include filters, elements, humidifier elements, etc. that pass through or come into contact with air during air conditioning or ventilation.

[0014] In the present disclosure and its embodiments, examples of "odor substances containing hydroxy groups" (odor components) include acetic acid, propionic acid, butyric acid, isovaleric acid, valeric acid, hexanoic acid, heptanoic acid, o-cresol, m-cresol, p-cresol, 2-ethyl-1-hexanol, 2,2,4-trimethyl-1,3-pentanediol-3-monoisobutyrate (Texanol), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TxiB), 2,4,6-trichloroanisole, 2-methylisoborneol, diosmin, 2,4-dichlorophenol, 2,6-dichlorophenol, 2,4-dibromophenol, 2,6-dibromophenol, 1-octen-3-ol, and 4-methyl-3-hexenoic acid. These substances are examples, and "odor substances containing hydroxy groups" are not limited to these. The hydroxy group is also called a hydroxyl group or a hydroxyl group.

[0015] The expression "contained" in a resin part includes, but is not limited to, the case where the odorous substance is contained in the material of the resin part itself, and also includes the case where the odorous substance is adsorbed on the surface of the resin part.

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0017] Embodiment 1 <System configuration> 1 is a diagram showing the configuration of an off-odor determination system for a resin part according to embodiment 1. The off-odor determination system 100 includes a first chamber 1, a second chamber 2, a sensor 3, a blank gas source 4, a first pipe 51, a second pipe 52, a third pipe 53, a first regulator 61, a second regulator 62, a heater 7, a controller 8, and a power source 9.

[0018] The first chamber 1 is a sealed container that houses the sensor 3. The size of the first chamber 1 is preferably small as long as it can house the sensor 3. The size of the first chamber 1 is, for example, 150 mm x 200 mm x 50 mm or less.

[0019] The second chamber 2 is a sealed container that contains the resin part 10 to be inspected. The volume of the second chamber 2 is preferably within a range of 5 mL to 200 mL. The second chamber 2 may be, for example, a wash bottle or a vial.

[0020] The sensor 3 includes a sensitive film 31 and wiring 32. The sensitive film 31 is also called a receptor layer. The sensitive film 31 is a layer disposed (coated) on the surface of the substrate of the sensor 3, and interacts with odorants. The interaction with odorants includes adsorption, permeation, and desorption of the odorants. Inorganic and organic materials can be mainly used as materials for the sensitive film 31.

[0021] Specifically, inorganic materials that can be used include silica / titania nanoparticles whose surfaces are modified with hydrophilic or hydrophobic functional groups such as aminopropyl, phenyl, octadecyl, vinyl, and tetraethoxysilane. Inorganic materials with nanoporous structures (e.g., titanium tetraisopropoxide (TTIP) and tetraethoxysilane (TEOS)) can also be used. Other alloys or metal complexes can also be used.

[0022] Examples of organic materials that can be used include polymethylmethacrylate (PMMA), polyvinylpyrrolidone (PVP), 2,6-diphenyl-p-phenylene oxide (TENAX-TA), polystyrene (PS), polycaprolactone (PCL), poly-(4-methylstyrene) (P4MS), polyvinylidene difluoride (PVDF), polyacrylic acid (PAA), polysulfone (PSF), carboxymethyl cellulose (CMC), polyethylene oxide (PEO), poly(styrene-co-butadiene), polyvinyl fluoride (PVF), cellulose acetate butyrate, and polyethylenimine (PEI).

[0023] The manufacturer of the off-odor determination system 100 (typically, a testing equipment manufacturer) may use a commercially available film that is applied to the surface of a substrate as the sensitive film 31. The manufacturer of the off-odor determination system 100 may also form the sensitive film 31 by applying the material for the sensitive film 31 (various organic or inorganic materials) to the surface of the substrate.

[0024] The sensor 3 is also called a transducer. The sensor 3 detects the interaction between the sensitive film 31 and odor components and converts the detected interaction into a signal. The sensor 3 outputs a signal indicating the interaction between the sensitive film 31 and odor components (hereinafter also referred to as a "sensor signal") to the controller 8 via a wiring 32. Specifically, the sensor 3 may be a film-type surface stress sensor, a quartz crystal sensor, a CMOS (Complementary Metal Oxide Semiconductor) odor sensor, or a PZT (Lead Zirconate Titanate) piezoelectric thin film sensor. The sensor 3 may be a commercially available sensor (off-the-shelf product) or a specially prepared sensor (custom-made sensor). The sensor 3 may be a single sensor or multiple sensors.

[0025] The blank gas source 4 supplies a blank gas (for example, high-purity nitrogen gas) that does not contain odorants or water vapor. The blank gas source 4 is, for example, a high-pressure gas container (gas cylinder).

[0026] The first pipe 51 connects the blank gas source 4 and the first chamber 1, and is configured to distribute the blank gas from the blank gas source 4 to the first chamber 1. The second pipe 52 connects the blank gas source 4 and the second chamber 2, and is configured to distribute the blank gas from the blank gas source 4 to the second chamber 2. The third pipe 53 connects the second chamber 2 and the first chamber 1, and is configured to distribute the gas from the second chamber 2 to the first chamber 1.

[0027] The first regulator 61 is provided in the first pipe 51 and adjusts the flow rate of the blank gas flowing through the first pipe 51 (or the pressure in the first pipe 51). The second regulator 62 is provided in the second pipe 52 and adjusts the flow rate of the blank gas flowing through the second pipe 52 (or the pressure in the second pipe 52). The first regulator 61 and the second regulator 62 may be controlled in accordance with a control command from the controller 8.

[0028] The first chamber 1 is provided with a first port P1, a second port P2, and a third port P3. The first port P1 is a port for introducing blank gas from the first piping 51 into the first chamber 1. The second port P2 connects the first chamber 1 and the second chamber 2 and is a port for introducing gas from the second chamber 2 into the first chamber 1. The third port P3 is a port for discharging gas from the first chamber 1 to the outside air.

[0029] Each of the first port P1 to the third port P3 is switched between open and closed states in accordance with a control command from the controller 8. For example, each of the first port P1 to the fourth port P4 is provided with a cock (not shown). When blank gas is to be circulated, the controller 8 opens the cock, while when blank gas is not to be circulated, the controller 8 closes the cock. By controlling the opening and closing of the cock at appropriate timing, the first chamber 1 can be maintained in a sealed state.

[0030] The second chamber 2 is provided with a fourth port P4 and a fifth port P5. The fourth port P4 is a port for introducing blank gas from the first chamber 1 into the second chamber 2. The fifth port P5 connects the second chamber 2 and the first chamber 1 and is a port for transferring gas from the second chamber 2 to the first chamber 1. The fourth port P4 and the fifth port P5 are also switched between open and closed states according to control commands from the controller 8.

[0031] The first chamber 1 is further provided with a minute hole for passing a wire 32 of the sensor 3. The wire 32 is used to supply a voltage to the sensor 3 and to extract a signal from the sensor 3.

[0032] The heater 7 receives power from a power source 9 and heats the resin part 10 under the control of a controller 8. The heater 7 is, for example, a PTC (Positive Temperature Characteristic) thermistor. The heater 7 may also be an oven that can heat the second chamber 2 containing the resin part 10.

[0033] The controller 8 controls the components of the off-odor determination system 100. More specifically, the controller 8 controls the heater 7 and also controls the gas source for circulating gas. Based on the sensor signal, the controller 8 also determines whether the resin part 10 contains odorous substances that exceed a threshold level.

[0034] The controller 8 includes a processor 81 and a memory 82. The processor 81 is an arithmetic processing device such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The memory 82 may include a volatile memory such as a RAM (Random Access Memory) and a rewritable nonvolatile memory such as an SSD (Solid State Drive) or a flash memory. The memory 82 stores system programs including an OS (Operating System) and control programs including computer-readable code required for arithmetic processing. The processor 81 performs various processes by reading the system programs and control programs and expanding them in the memory 82. While FIG. 1 shows an example in which the controller 8 includes one processor 81, the controller 8 may include multiple processors. The same applies to the memory 82.

[0035] In this specification, the term "processor" is not limited to a processor in the narrow sense that executes processing using a stored program, but may also include hardwired circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). Therefore, the term "processor" can also be interpreted as a processing circuitry whose processing is predefined by computer-readable code and / or hardwired circuitry.

[0036] The power supply 9 supplies an operating voltage to the sensor 3 , supplies an operating voltage to the controller 8 , and supplies power to the heater 7 .

[0037] <Abnormality detection flow> Fig. 2 is a flowchart showing the processing steps of the manufacturing method for an air conditioner according to the first embodiment. The processing shown in this flowchart is called from a main routine (not shown) and executed when a predetermined condition is met. Each step is realized by software processing by the controller 8 (processor 81), but may also be realized by hardware (electrical circuitry) arranged within the controller 8. The same applies to the processing shown in the flowchart of Fig. 6, which will be described later. Hereinafter, steps will be abbreviated as S.

[0038] In the first embodiment, the inspection of the resin parts 10 for abnormal odors does not have to be performed on all of the resin parts 10. A small number of resin parts 10 per lot may be inspected. Inspection may also be performed at regular intervals (so-called periodic sampling inspection).

[0039] <Heating of small parts> 1 and 2, it is assumed that in an initial state, the first chamber 1 and the second chamber 2 are not connected. The resin part 10 may be housed inside the second chamber 2 or may be disposed outside the second chamber 2.

[0040] In S101, the controller 8 controls the heater 7 to heat the resin part 10. The heater 7 may heat the resin part 10 outside the second chamber 2, or may heat the resin part 10 inside the second chamber 2 together with the second chamber 2. Heating the resin part 10 increases the amount of odorous substances released from the resin part 10, making it easier for the sensor 3 to detect odorous substances containing hydroxy groups.

[0041] The heating temperature is preferably 50 to 90° C., more preferably 60 to 80° C. The heating time is preferably 1 to 48 hours, more preferably 16 to 32 hours.

[0042] On the other hand, it is preferable to avoid heating at too high a temperature or for too long a time, because in such cases, substances other than the hydroxyl group-containing odorous substance to be detected (other volatile substances) are released in large quantities from the resin part 10, making accurate determination impossible. The reason why the heating temperature is desirably within the above temperature range will be explained in more detail below.

[0043] 3 shows an example of the results of a sensory evaluation of odor intensity before and after heating when the resin part 10 is a rubber part. A six-level odor intensity display method was used, in which odor intensity is displayed in six levels, ranging from 0 to 5 (0: no odor, 1: barely detectable odor, 2: weak odor that is recognizable, 3: easily detectable odor, 4: strong odor, 5: overwhelming odor).

[0044] Samples A and B are off-odor products, while samples C and D are non-off-odor products. Figure 3 shows that when the samples are not heated, the odor intensity of the off-odor products is similar to that of the non-off-odor products, whereas when the samples are heated at the appropriate temperature (70°C), the odor intensity of the off-odor products increases significantly.

[0045] On the other hand, heating the sample at an excessively high temperature (130°C) increases the odor intensity even for non-offensive odor products. When the resin part 10 is a rubber part, hydrocarbons contained within the rubber part are released, and the boiling point of hydrocarbons is between 80°C and 130°C. Therefore, heating temperatures close to the boiling point of hydrocarbons increase the amount of hydrocarbons released. Even when the resin part 10 is made of ABS, PS, or PET, the glass transition temperature of the resin part 10 is between 70°C and 110°C. Therefore, heating temperatures excessively higher than the glass transition temperature increase the amount of volatile substances released from the resin part 10's materials (base material, additives, etc.). As a result, even though the resin part 10 does not have an offensive odor, it exhibits an odor intensity equivalent to that of an offensive odor product. Therefore, to ensure a significant difference in odor intensity between offensive odor products and non-offensive odor products, it is desirable not to use an excessively high heating temperature.

[0046] 1 and 2, the heated resin part 10 is housed in the second chamber 2. As described above, the second chamber 2 housing the resin part 10 may be heated as a whole. Below, an example will be described in which the first regulator 61, the second regulator 62, and the first port P1 to the fifth port P5 are automatically controlled by the controller 8. However, some or all of these components may also be manually controlled by an operator in charge of inspection.

[0047] If a large amount of odorous substances is released from the resin part 10 without heating, step S101 may be omitted. Generally, many odorous components have a low olfactory threshold (the minimum concentration at which the human nose detects an odor). Therefore, it should be noted that even if the human nose can detect the odor, only a very small amount of odorous substances may be released.

[0048] <Blank Gas Distribution> At this stage, the second chamber 2 is not connected to the first chamber 1. The first port P1 is open. The second port P2 is closed. The third port P3 is open.

[0049] In S102, the controller 8 controls the first regulator 61 so that the blank gas supplied from the blank gas source 4 flows to the sensor 3 in the first chamber 1.

[0050] The influence of water vapor (humidity) inside the first chamber 1 can cause noise to be superimposed on the sensor signal, change the offset of the sensor signal, and otherwise make the operation of the sensor 3 unstable. Therefore, filling the first chamber 1 with blank gas reduces the influence of water vapor, enabling stable operation of the sensor 3. The controller 8 may, for example, continue the flow of blank gas until the sensor signal becomes constant (stabilized). The controller 8 may also continue the flow of blank gas until the humidity measured by a hygrometer (not shown) arranged in the first chamber 1 falls below a target value. The target value is, for example, 5%, and more preferably 0.5%.

[0051] <<Acquisition of sensor signals>> After the sensor signal stabilizes, the first chamber 1 and the second chamber 2 are connected via the third pipe 53 (the fifth port P5 and the second port P2). The first port P1 is open. The second port P2 is closed. The third port P3 is open. The fourth port P4 is closed. The fifth port P5 is closed.

[0052] In S103, the controller 8 controls the second regulator 62 and each port so that blank gas from the blank gas source 4 flows into the second chamber 2. In addition, the controller 8 controls the first regulator 61 and each port so that direct inflow of blank gas from the blank gas source 4 into the first chamber 1 is stopped. More specifically, the controller 8 closes the first port P1, opens the second port P2, opens the fourth port P4, and opens the fifth port P5. Then, if the resin part 10 contains an odorous substance, the odorous substance released from the resin part 10 is mixed with the blank gas inside the second chamber 2 to generate an odorous gas. The generated odorous gas moves from the second chamber 2 to the first chamber 1. The controller 8 acquires a signal (sensor signal) from the sensor 3 indicating the detection result of an odorous substance that may be contained in the odorous gas.

[0053] <Feature extraction> In S104, the controller 8 extracts, from the sensor signals, a feature value relating to whether or not the odorous gas contains an odorous substance. In this embodiment, the feature value is the voltage value (hereinafter also referred to as "sensor voltage") of each sensor signal at a time when a specified time has elapsed since the odorous gas started to flow.

[0054] FIG. 4 is a time chart for explaining an example of a feature extraction method. In this example, four sensors 3 are used. The four sensors 3 have different types of sensitive films 31 (types of materials applied to the substrate surface). The horizontal axis represents elapsed time, and the vertical axis represents sensor voltage.

[0055] First, the first port P1 was opened, the second port P2 was closed, and the third port P3 was opened, and blank gas was allowed to flow for 60 seconds into the first chamber 1. Next, the first port P1 was closed, the second port P2 was opened, the third port P3 was opened, the fourth port P4 was opened, and the fifth port P5 was opened, and the odorous gas in the second chamber 2 was introduced into the first chamber 1 for 180 seconds. Finally, the first port P1 was opened, the second port P2 was closed, and the third port P3 was opened, and blank gas was allowed to flow for 300 seconds into the first chamber 1.

[0056] When the first blank gas was passed through, the sensor voltage was nearly 0 V. When the odorous gas was introduced, the sensor voltage dropped significantly. Furthermore, when the blank gas was passed through again after the odorous gas was introduced, the sensor voltage returned to 0 V over time.

[0057] In this example, the sensor voltage (i.e., the sensor voltage immediately before switching from the odorous gas to the blank gas) at the point 180 seconds after the start of the odorous gas flow (the point 240 seconds after the start of the first blank gas flow) was extracted as a feature. Since four sensors 3 were used, four feature values ​​were extracted.

[0058] The feature may be an absolute value of the sensor voltage as in this example, or, if multiple feature values ​​are extracted, each feature may be a relative value of the sensor voltage (e.g., a relative value of another sensor voltage with respect to a reference sensor voltage).

[0059] <Determining abnormal odors> In S105, the controller 8 performs multivariate analysis on the feature quantities extracted in S104. An example of the results of the multivariate analysis when cresol is used as an odorant containing a hydroxy group will be described.

[0060] Eight samples with an off-odor and six samples without an off-odor were prepared. Each of the eight samples with an off-odor was a mixture of cresol and a liquid without an off-odor, which was then applied to filter paper. The liquid without an off-odor was a liquid with a high olfactory threshold (a liquid that the human nose cannot easily detect). The eight samples with an off-odor differed in the concentration of cresol and the concentration of the liquid without an off-odor. Each of the six samples without an off-odor was a liquid without an off-odor that was applied to filter paper. The six samples without an off-odor differed in the concentration of the liquid without an off-odor. Note that each sample may be a liquid placed directly in a container such as a cup, instead of being applied to filter paper.

[0061] Four feature quantities were extracted for each sample by performing measurements similar to those described in Figure 4. In this example, the dimensions were reduced (shrinked) by principal component analysis of the four feature quantities, and the first and second principal components were found.

[0062] FIG. 5 is a diagram illustrating an example of the results of determining whether an off-odor is present using principal component analysis. The horizontal axis represents the second principal component, and the vertical axis represents the first principal component. From FIG. 5, it can be seen that the second principal component obtained from samples without an off-odor is distributed within a positive range, while the second principal component obtained from samples with an off-odor is distributed within a negative range. In this case, for example, the line where the second principal component is 0 can be set as the threshold level. This makes it possible to clearly distinguish between samples with an off-odor and those without.

[0063] The controller 8 may use other known methods (such as cluster analysis) as multivariate analysis instead of principal component analysis.

[0064] Multivariate analysis is not required. For example, a trained model of supervised learning using samples with an off-odor and samples without an off-odor may be stored in the memory 82 of the controller 8. This also allows the controller 8 to clearly distinguish between samples with an off-odor and samples without an off-odor by inputting feature values ​​into the trained model.

[0065] Returning to FIG. 2, in S106, the controller 8 determines whether the resin part 10 has an abnormal odor based on whether the variables obtained by the multivariate analysis satisfy a condition corresponding to a threshold level. Regarding the example of FIG. 5, if the second principal component obtained by the multivariate analysis is less than the threshold level (second principal component = 0), the controller 8 determines that the condition is satisfied (YES in S106) and determines that the resin part 10 has an abnormal odor (S107). The resin part 10 is not used in air conditioners (S108). In this case, the resin part 10 with an abnormal odor may be recycled or may be subjected to investigation to determine the cause of the abnormal odor.

[0066] On the other hand, if the second principal component is equal to or greater than the threshold level, the controller 8 determines that the condition is not satisfied (NO in S106) and determines that the resin part 10 does not have an abnormal odor (S109). The resin part 10 that does not have an abnormal odor is installed in an air conditioner (S110). A certain period of time may be set between the time when the resin part 10 is determined to have no abnormal odor and the time when the resin part 10 is installed in an air conditioner.

[0067] As described above, in the first embodiment, a resin part 10 is inspected before being installed in an air conditioner to determine whether it is emitting odorous substances containing hydroxyl groups. More specifically, the controller 8 acquires a sensor signal from the sensor 3, which is provided with a sensitive film 31 that interacts with odorous substances containing hydroxyl groups. The controller 8 then extracts multiple feature quantities from the sensor signal and performs multivariate analysis on the extracted feature quantities. Based on the results of the multivariate analysis, the controller 8 determines whether the resin part 10 is emitting odorous substances at a level that could cause an unpleasant odor. A resin part 10 determined to have an unpleasant odor is removed without being installed in the air conditioner. Therefore, according to the first embodiment, it is possible to suppress unpleasant odors that may be emitted from the air conditioner.

[0068] Embodiment 2 6 is a diagram showing the configuration of an off-odor determination system for a resin part 10 according to embodiment 2. Off-odor determination system 200 differs from off-odor determination system 100 according to embodiment 1 (see FIG. 1) in that it further includes a moisture supplying device 11.

[0069] The moisture supplying device 11 supplies moisture to the resin part 10 in accordance with a control command from the controller 8. The moisture supplying device 11 is, for example, a spray bottle, a dropper, a pipette, a dispenser, or a water supply tube. The moisture supplied from the moisture supplying device 11 is, for example, tap water, pure water, ultrapure water, RO (reverse osmosis) water, or ion-exchanged water. The moisture supplying device 11 may be manually operated by an operator.

[0070] In particular, when the resin part 10 is a part that allows air to pass through (such as a filter, element, or humidifying element), odorous substances adsorbed on the surface of the resin part 10 can cause an unpleasant odor. Therefore, in this embodiment, prior to heating the resin part 10, a process of supplying moisture to the resin part 10 is carried out. Hydroxyl groups of odorous substances are adsorbed to polar groups present on the surface of the resin part 10 through hydrogen bonding. By supplying moisture to the resin part 10, the odorous substances are replaced by moisture. That is, moisture is adsorbed on the surface of the resin part 10, and the odorous substances are desorbed from the surface of the resin part 10 instead. This increases the amount of odorous substances containing hydroxyl groups released. As a result, the detection accuracy of odorous substances containing hydroxyl groups can be improved.

[0071] 7 is a flowchart showing the processing steps of the method for manufacturing an air conditioner according to embodiment 2. This flowchart differs from the flowchart in embodiment 1 (see FIG. 2) in that it includes the processes of S201 to S205 and S209.

[0072] When moisture is supplied to the resin part 10, the sensor 3 may be affected by the moisture. The processes of S201 to S204 are processes for canceling (reducing) the effect of moisture on the sensor 3. It is assumed that, in the initial state, the resin part 10 is not housed inside the second chamber 2, and the first chamber 1 and the second chamber 2 are connected.

[0073] In S201, the controller 8 controls the moisture supply device 11 to supply moisture to the empty second chamber 2 that does not contain the resin part 10. The amount of moisture supplied to the second chamber 2 is preferably equal to the amount of moisture supplied to the resin part 10 in S205, which will be described later.

[0074] In S202, the controller 8 controls the heater 7 to heat the empty second chamber 2.

[0075] In S203, the controller 8 controls the first regulator 61 and each port so that the blank gas flows into the first chamber 1. This stabilizes the sensor signal.

[0076] In S204, the controller 8 controls the second regulator 62 and each port so that the blank gas flows into the second chamber 2. In addition, the controller 8 controls the first regulator 61 and each port so that the direct flow of the blank gas from the blank gas source 4 into the first chamber 1 is stopped. The controller 8 acquires a sensor signal for the blank gas that has moved from the second chamber 2 to the first chamber 1 as a so-called background signal.

[0077] In S205, the controller 8 controls the water supply device 11 to supply water to the resin part 10. If the water supply device 11 is a sprayer, it is preferable that the water supply device 11 sprays water to the extent that the entire resin part 10 is wet. If the water supply device 11 is a dropper, pipette, dispenser, or water supply tube, it is preferable that the water supply device 11 drips a few drops of water onto the resin part 10.

[0078] Thereafter, the resin part 10 is placed inside the second chamber 2. The subsequent processes of S206 to S208 are similar to the processes of S101 to S103 in the first embodiment (see FIG. 2), and therefore description thereof will not be repeated.

[0079] In S209, the controller 8 calculates a difference by subtracting the background signal acquired in S204 from the sensor signal acquired in S208. This allows the controller 8 to acquire a sensor signal in which the effect of moisture on the sensor 3 has been cancelled out.

[0080] In S210, the controller 8 extracts a feature amount from the sensor signal in which the influence of moisture on the sensor 3 has been cancelled out. This extraction method is the same as the method described with reference to FIG.

[0081] The subsequent processes of S211 to S216 are similar to the processes of S104 to S110 in the first embodiment (see FIG. 2), and therefore description thereof will not be repeated.

[0082] As described above, in the second embodiment, similar to the first embodiment, whether or not odorous substances containing hydroxyl groups are being emitted from the resin part 10 before it is installed in the air conditioner is inspected. If the resin part 10 is determined to have an abnormal odor based on the sensor signal, it is not installed in the air conditioner. Therefore, according to the first embodiment, it is possible to suppress the abnormal odor that may be emitted from the air conditioner.

[0083] Additionally, in the second embodiment, by supplying moisture to the resin part 10 prior to heating the resin part 10, the amount of odorous substances containing hydroxyl groups released from the resin part 10 increases compared to when moisture is not supplied to the resin part 10. This improves the detection accuracy of odorous substances containing hydroxyl groups.

[0084] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0085] 100,200 Odor detection system, 1 First chamber, 2 Second chamber, 3 Sensor, 31 Sensitive membrane, 32 Wiring, 4 Blank gas source, 51 First piping, 52 Second piping, 53 Third piping, 61 First regulator, 62 Second regulator, 7 Heater, 8 Controller, 81 Processor, 82 Memory, 9 Power supply, 10 Resin part, 11 Moisture supply device, P1 First port, P2 Second port, P3 Third port, P4 Fourth port, P5 Fifth port.

Claims

1. A step of passing a gas through a resin part before being assembled into an air conditioner and acquiring a signal from at least one sensor having a sensitive film disposed thereon that interacts with an odorous substance containing a hydroxy group; and determining whether or not an abnormal odor is present in the resin part based on the signal.

2. The method for manufacturing an air conditioner according to claim 1 , further comprising the step of heating the resin part prior to the step of obtaining.

3. The method for manufacturing an air conditioner according to claim 2, wherein the heating step includes a step of heating the resin part at 60°C to 80°C.

4. The method for manufacturing an air conditioner according to claim 3 , further comprising the step of supplying moisture to the resin part prior to the heating step.

5. the at least one sensor includes a plurality of sensors in which the sensitive film is made of a material different from each other; The manufacturing method includes: extracting, as a plurality of feature quantities, a plurality of voltage values ​​indicated by signals from the plurality of sensors at a time point when a predetermined time has elapsed since the start of the gas flow; and performing a multivariate analysis of the plurality of feature quantities. The method for manufacturing an air conditioner according to any one of claims 1 to 4, wherein the determining step includes a step of determining whether or not the resin part has an unpleasant odor based on the results of multivariate analysis of the plurality of feature quantities.

6. The method for manufacturing an air conditioner according to any one of claims 1 to 4, further comprising the step of not incorporating the resin part into the air conditioner if it is determined that the resin part has an anomalous odor, and incorporating the resin part into the air conditioner if it is determined that the resin part does not have an anomalous odor.

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