Cooling/heating switching unit and air conditioner including the same

{
  "publication_number": "US10557648B2",
  "country": "US",
  "kind": "B2",
  "title": "Cooling/heating switching unit and air conditioner including the same",
  "abstract": "A cooling/heating switching unit includes first to third fittings, expansion valves and expansion-valve driving sections, a housing, a heat insulating material, and a refrigerant leak detection sensor. The first and second fittings respectively connect with a high/low-pressure-gas main pipe and a low-pressure-gas main pipe, which are linked to an outdoor unit. The third fitting connects with an indoor-unit connection pipe, which is linked to indoor units. The expansion valve for high/low-pressure-gas pipe, the expansion valve for low-pressure-gas pipe, and expansion-valve driving sections selectively connect the first or second fitting with the third fitting via a refrigerant pipe to control a flow direction of refrigerant. The housing houses the refrigerant pipe. The heat insulating material fills inside of the housing to insulate the refrigerant pipe arranged inside of the housing from heat. The refrigerant leak detection sensor is installed outside of the housing to detect leaked refrigerant.",
  "claims": [
    "1. A cooling/heating switching unit for connection with two or more use-side units and a heat-source-side unit to constitute an air conditioner, the two or more use-side units being independently operable to perform cooling and heating simultaneously, the cooling/heating switching unit comprising: a first-refrigerant-pipe fitting and a second-refrigerant-pipe fitting that have a first refrigerant pipe and a second refrigerant pipe connected thereto, respectively, wherein the first and second refrigerant pipes are linked to the heat-source-side unit; a third-refrigerant-pipe fitting that has a third refrigerant pipe connected thereto, wherein the third refrigerant pipe is linked to the use-side unit; a first expansion valve and a second expansion valve that are configured to control a flow direction of refrigerant from either the first-refrigerant-pipe fitting or the second-refrigerant-pipe fitting to the third-refrigerant-pipe fitting, via a fourth refrigerant pipe, based on a combination of an open state or a closed state of the first expansion valve and the second expansion valve; a housing that houses at least a part of the fourth refrigerant pipe; and a refrigerant leak detection sensor that is disposed outside of the housing to detect leaked refrigerant.",
    "2. The cooling/heating switching unit according to claim 1, further comprising additional refrigerant leak detection sensors that are respectively disposed below the first-refrigerant-pipe fitting, the second-refrigerant-pipe fitting, and the third-refrigerant-pipe-fitting.",
    "3. The cooling/heating switching unit according to claim 1, wherein at least one of the first-refrigerant-pipe fitting, the second-refrigerant-pipe fitting, and the third-refrigerant-pipe fitting are flare connected to the respective first refrigerant pipe, the second refrigerant pipe, and the third refrigerant pipe.",
    "4. The cooling/heating switching unit according to claim 1, wherein the refrigerant leak detection sensor is disposed below the housing.",
    "5. The cooling/heating switching unit according to claim 1, wherein the refrigerant leak detection sensor is connected, via an electric signal line for electrical connection, to a circuit board included in the cooling/heating switching unit, and the length of the electric signal line is one that allows the refrigerant leak detection sensor to be moved to a point below the housing.",
    "6. The cooling/heating switching unit according to claim 5, wherein the length of the electric signal line is equal to or longer than the length obtained by adding 50 mm to the distance from the circuit board to a bottom surface of the housing.",
    "7. The cooling/heating switching unit according to claim 1, wherein the refrigerant leak detection sensor is connected, via an electric signal line which is electrically connected to a circuit board included in the cooling/heating switching unit, and wherein the circuit board includes at least one of a buzzer that emits sound when a leak of refrigerant is detected by the refrigerant leak detection sensor and a light-emitting diode (LED) that emits light when a leak of refrigerant is detected by the refrigerant detection sensor.",
    "8. An air conditioner comprising: two or more use-side units being independently operable to perform cooling and heating simultaneously; a heat-source-side unit that are used to form a refrigeration cycle between the heat-source-side unit and the two or more use-side units; a first-refrigerant-pipe fitting and a second-refrigerant-pipe fitting that have a first refrigerant pipe and a second refrigerant pipe connected thereto, respectively, wherein the first and second refrigerant pipes are linked to the heat-source-side unit; a third-refrigerant-pipe fitting that has a third refrigerant pipe connected thereto, wherein the third refrigerant pipe is linked to the use-side unit; a first expansion valve and a second expansion valve that are configured to control a flow direction of refrigerant from either the first-refrigerant-pipe fitting or the second-refrigerant-pipe fitting to the third-refrigerant-pipe fitting, via a fourth refrigerant pipe, based on a combination of an open state or a closed state of the first expansion valve and the second expansion valve; a housing that houses at least a part of the fourth refrigerant pipe; and a refrigerant leak detection sensor that is disposed outside of the housing to detect leaked refrigerant."
  ],
  "description_excerpt": "The present invention relates to a cooling/heating switching unit used in a multi-system air conditioner for simultaneous cooling and heating, and an air conditioner that includes the cooling/heating switching unit, and more particularly, to detection of leaked refrigerant in the cooling/heating switching unit.\n\nBecause of the influence on global warming due to refrigerant used in air conditioners, using alternative refrigerant (R32, and HFO refrigerant such as R1234yf and R1234ze) having a small global warming coefficient has been examined instead of using conventional refrigerant (R404A and R410A). In addition, a technique of detecting leaked refrigerant has been examined so that, in an air conditioner, any leak of refrigerant can quickly be detected to take action even if it happens.\n\nWith respect to a technique of detecting leaked refrigerant, a technique described in Japanese Patent Application Publication No. 2015-42930 is known. Japanese Patent Application Publication No.",
  "cpc": [
    "F25B 13/00",
    "F24F 1/32",
    "F24F 11/36",
    "F24F 2221/54",
    "F25B 2313/007",
    "F25B 2313/0231",
    "F25B 2313/0233",
    "F25B 2313/02732",
    "F25B 2313/02742",
    "F25B 2500/222",
    "F25B 49/02"
  ],
  "ipc": [
    "F25B 13/00",
    "F25B 41/42",
    "F25B 49/02"
  ],
  "assignees": [
    "Hitachi Johnson Controls Air Conditioning Inc"
  ],
  "inventors": [
    "Koji Naito",
    "Naoyuki FUSHIMI",
    "Kazumoto Urata",
    "Gen Yasuda",
    "Kazunori Fukuda"
  ],
  "filing_date": "2017-06-09",
  "publication_date": "2020-02-11",
  "grant_date": "2020-02-11",
  "priority_date": "2016-07-15",
  "application_number": "US-201715618321-A",
  "family_id": "59313081",
  "cited_by_count": 9,
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}