JP4464796B2 - Heat exchanger and manufacturing method thereof - Google Patents

Description

  The present invention relates to a heat exchanger and a method for manufacturing the same, and is particularly suitable for a heat exchanger having aluminum fins used in devices such as an air conditioner, a refrigerator, a dehumidifier, and an automobile, and a method for manufacturing the same.

  A general heat exchanger used in an air conditioner, a refrigerator, or the like is configured by combining a copper pipe for flowing a refrigerant therein and an aluminum fin having a hydrophilic layer on the surface. In such a heat exchanger, powdered non-eluting titanium oxide having a particle size of several μm is added to the hydrophilic layer, and the titanium oxide is excited by irradiating ultraviolet rays having a wavelength of 400 nm or less to oxidize and decompose odor components. It is considered to have a photocatalytic function. The hydrophilic layer to which titanium oxide is added is formed by dipping or the like after combining a copper pipe and an aluminum fin. Furthermore, in a heat exchanger having a photocatalytic function, it is also considered that silver is supported on titanium oxide to improve antibacterial performance.

  Patent documents related to the prior art include JP-A-8-269992 (Patent Document 1) and JP-A-2001-201288 (Patent Document 2).

JP-A-8-269992 JP 2001-201288 A

  However, in conventional heat exchangers, titanium oxide used as a photocatalyst is a powder with a particle size of several μm and is non-eluting, so it is difficult to expose many photocatalyst particles on the surface of the hydrophilic layer, and the hydrophilic layer is thick. Therefore, it was necessary to use it as a binder for the photocatalyst. For this reason, for example, as disclosed in Patent Document 1, a light for irradiating the heat exchanger with ultraviolet rays is provided inside the air conditioner, or light for taking in indoor light instead of the light and irradiating the heat exchanger. A sufficient deodorizing performance cannot be obtained unless a transmissive window is provided to irradiate the heat exchanger strongly with light, and the heat exchange performance is reduced due to the thick hydrophilic layer.

  In addition, since the photocatalyst that is an inorganic particle of several μm exists in the hydrophilic layer, the adhesion of the hydrophilic layer to the aluminum fins is reduced, and the hydrophilicity that is the original function of the hydrophilic layer is also reduced. There has been a problem that reliability and heat exchange performance deteriorate.

  Furthermore, in the heat exchanger of an air conditioner, a protective layer is formed on the hydrophilic layer of the aluminum fin for the purpose of protection until the heat exchanger is completed. This protective layer is washed away with dew condensation water generated on the surface of the heat exchanger when it is operated by being incorporated in an air conditioner, for example. Conventionally, the hydrophilic layer and the protective layer are applied to the fin surface with a mixed solution, and the components of the protective layer are eluted to the surface side during sintering, and as a result, the two layers are manufactured. However, since non-eluting titanium oxide is added in a powder with a particle size of several μm, titanium oxide is evenly dispersed in the hydrophilic layer and the protective layer in the conventional mixed liquid manufacturing method. It is not possible to add a large amount of titanium oxide alone. For this reason, in order to add a large amount of titanium oxide only to the hydrophilic layer, it is necessary to form a protective layer after adding a large amount of titanium oxide to the hydrophilic layer, which increases the number of processes. There has been a problem of increasing costs.

  Furthermore, in the case of forming a general hydrophilic layer that does not have a deodorizing function in a conventional heat exchanger, a combination of aluminum fins previously formed with a hydrophilic layer and a copper pipe is considered to be highly productive. Yes. However, with aluminum fins that have been previously formed with a hydrophilic layer to which titanium oxide with a particle size of several μm is added, when machining holes for passing copper pipes through the aluminum fins, the machining die is immediately worn by this titanium oxide. Resulting in. For this reason, after combining a copper pipe and an aluminum fin, the hydrophilic layer has to be formed by dipping or the like, which causes a problem of reducing productivity.

  In addition, when silver, which is a metal that has a lower ionization tendency than copper pipes, is supported on titanium oxide to improve the photocatalytic function, local water corrosion occurs when condensed water is generated in the heat exchanger, and the copper pipes. There was a problem that copper ions were eluted from the steel and corroded.

  An object of the present invention is to provide a heat exchanger that can prevent local current corrosion due to condensation at a low cost and can obtain sufficient deodorizing performance with little light while improving the adhesion and hydrophilicity of the hydrophilic layer, and It is in providing the manufacturing method.

In order to achieve the above object, the present invention provides a copper pipe through which a coolant flows, a large number of copper pipes that are lined up through the copper pipe and a hydrophilic layer is formed on an aluminum material, and dew condensation is formed on the surface of the hydrophilic layer. In a heat exchanger provided with an aluminum fin formed with a protective layer washed away with water, the hydrophilic layer and the protective layer have a nanoparticle deodorizing antibacterial material in which zinc is supported on titanium oxide , the hydrophilic layer is densely distributed surface side of the aluminum material side the deodorizing antibacterial material, that the deodorizing antibacterial material is that the arrangement is distributed more towards the hydrophilic layer than towards the protective layer is there.

A more preferable specific configuration example of the present invention is as follows.
(1) The protective layer is mainly composed of polyethylene glycol .
(2) 80% or more of the deodorizing antibacterial material added to the hydrophilic layer and the protective layer is distributed in the hydrophilic layer.
(3) The average particle diameter of the deodorizing antibacterial material was about 10 nm.
(4) 2 to 40% by weight of the deodorizing antibacterial material is added to the hydrophilic layer.

In order to achieve the above object, the present invention provides a copper pipe through which a coolant flows, a large number of copper pipes that are lined up through the copper pipe and a hydrophilic layer is formed on an aluminum material, and dew condensation is formed on the surface of the hydrophilic layer. In a method of manufacturing a heat exchanger comprising an aluminum fin having a protective layer washed away with water, an aqueous solution containing a nanoparticle deodorizing antibacterial material in which zinc is supported on titanium oxide , a hydrophilic layer solution, and a protective layer solution. by firing the mixed mixture was applied to the surface of the aluminum material to form said protective layer comprising less the deodorizing antibacterial material and the hydrophilic layer containing a large amount of the deodorizing antibacterial material, the deodorizing antibacterial material there is in that so as to form the hydrophilic layer surface is densely distributed than the aluminum material side.

A more preferable specific configuration example of the present invention is as follows.
(1) The protective layer is mainly composed of polyethylene glycol .
(2) Use a deodorizing antibacterial material having an average particle size of about 10 nm as the deodorizing antibacterial material.
(3) After forming the hydrophilic layer and the protective layer on the aluminum material by the mixed solution using the hydrophilic layer solution composed of the component in which the deodorizing antibacterial material is more easily dispersed than the protective layer solution , the aluminum fin And assembling through the copper pipe.

  According to the present invention, a heat exchanger that can prevent local current corrosion due to condensation at low cost and can obtain sufficient deodorization performance with little light while improving the adhesion and hydrophilicity of the hydrophilic layer, and A manufacturing method thereof can be provided.

  Hereinafter, a heat exchanger according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to the drawings.

  First, an air conditioner to which the heat exchanger 5 of the present embodiment is applied will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of an indoor unit of an air conditioner to which the heat exchanger of this embodiment is applied.

  The indoor unit 50 of the air conditioner is configured with the housing 1, the heat exchanger 5, and the ventilation fan 6 as main components.

  The housing 1 is composed of a decorative frame 2 and a base frame 3, and has a suction port 1a and a blowout port 1b at the top and bottom. The ventilation fan 6 is disposed in the center of the housing 1 and operates to suck indoor air from the suction port 1a and blow it out from the blower port 1b, as indicated by a white arrow. The heat exchanger 5 includes an aluminum fin 5b having a copper pipe 5a through which a refrigerant flows and a hydrophilic layer 11 (see FIG. 2) having a deodorizing antibacterial function on an aluminum material. And is arranged on the suction side of the ventilation fan 6 so as to exchange heat with room air. In the heat exchanger 5, a refrigerant for cooling or heating indoor air flows inside. The heat exchanger 5 is generally formed in an inverted V shape, and dew trays 4 a and 4 b are installed at both lower ends of the front and rear of the heat exchanger 5.

  The air filter 7 and the prefilter 8 are for removing dust from the room air and cleaning the air, and are disposed on the suction side of the heat exchanger 5. Air conditioned room air is blown out into the room from the outlet 1b. The wind direction blade | wing 9 changes the blowing direction at the time of air_conditioning | cooling and heating.

  During the cooling operation of the air conditioner, the indoor air is sucked into the housing 1 from the suction port 1a, removed by the pre-filter 8 and the air filter 7 and cleaned with air, and further cooled by the heat exchanger 5, and then the ventilation fan. 6 is blown out into the room through the outlet 1b. Since this indoor air is in contact with the heat exchanger 5 with a deodorizing antibacterial function having a large surface area, it is possible to efficiently remove odor components in the air.

  Next, details of the aluminum fins 5b of the heat exchanger 5 will be described with reference to FIG. FIG. 2 is a schematic enlarged cross-sectional view of the surface portion of the heat exchanger 5 of the present embodiment.

  The aluminum fins 5 b of the heat exchanger 5 are configured by forming a base treatment layer 12, a hydrophilic layer 11, and a protective layer 13 in this order on the surface of the aluminum material 10. A deodorizing antibacterial material 14 is added in the hydrophilic layer 11 and the protective layer 13.

  The hydrophilic layer 11 is for making the surface of the aluminum fin 5 b hydrophilic, and is formed on the aluminum material 10 via the base treatment layer 12. The ground treatment layer 12 is for treating the hydrophilic layer 11 so that it can be formed on the aluminum material 10. The protective layer 13 is for the purpose of protection until the heat exchanger is completed. The protective layer 13 is mainly made of polyethylene glycol, and is washed away with condensed water generated on the surface of the heat exchanger when the air conditioner is operated. Is. Therefore, after the operation of the air conditioner is started, the hydrophilic layer 11 is exposed and comes into contact with the room air.

  The deodorizing antibacterial material 14 is a nanoparticle deodorizing antibacterial material in which zinc is supported on titanium oxide, and is added in the hydrophilic layer 11 so that the surface side is more densely distributed than the aluminum material side. In this embodiment, a nanoparticle deodorizing antibacterial material 14 having an average particle diameter of about 10 nm is added.

  As described above, since the deodorizing antibacterial material 14 is densely distributed on the surface side, the odor component adsorbed on the surface can be sufficiently oxidized and removed even with a slight amount of light, and has high deodorizing performance. Obtainable. In addition, since the nanoparticle deodorizing antibacterial material 14 is added to the hydrophilic layer 11, compared to the conventional case of adding several μm particles, the adhesion and hydrophilicity of the hydrophilic layer 11 are reduced. While being able to suppress, the deodorizing antibacterial material 14 can be densely distributed and added to the surface side of the thin hydrophilic layer 11. Thereby, it is possible to improve the reliability as the heat exchanger and improve the heat exchange performance. Furthermore, since zinc oxide, which has a higher ionization tendency than copper, is supported on titanium oxide, it is possible to prevent local current corrosion from occurring between zinc and the copper pipe at the time of dew condensation, and the deodorizing performance of the supported zinc. Improvements can be made.

  And the deodorizing antibacterial material 14 is added more to the hydrophilic layer 11 than to the protective layer 13. Specifically, 80% or more of the deodorizing antibacterial material 14 added to the hydrophilic layer 11 and the protective layer 13 is distributed in the hydrophilic layer 11. Thereby, when the protective layer 13 is used, it is possible to ensure high deodorizing performance while suppressing the amount of the deodorizing antibacterial material 14 to be inexpensive.

  Next, a method for manufacturing the heat exchanger 5 including a method for forming the hydrophilic layer 11 and the protective layer 13 will be described with reference to FIGS. 1 and 2.

  First, a hydrophilic layer solution, a protective layer solution, and an aqueous solution containing the deodorizing antibacterial material 14 are mixed, and this mixed solution is baked on the surface of the aluminum material 10 so that the deodorizing antibacterial material 14 is more closely attached to the surface side than the aluminum material side. A hydrophilic layer 12 that is distributed and contains more than the protective layer 13 and a protective layer 13 that contains less deodorized antibacterial material 14 are formed. As an aqueous solution containing the deodorizing antibacterial material 14, a catalyst having zinc supported on titanium oxide was used. The catalyst used is composed of nano colloidal water-dispersed nanoparticles having high stability, and zinc having a higher ionization tendency than copper is supported on titanium oxide.

  Here, this catalytic action will be briefly described. When energy such as heat and light is applied to titanium oxide (Tio2), titanium oxide is excited and electrons are emitted. Then, electrons move from zinc existing in the vicinity to titanium oxide. As a result, zinc becomes a zinc ion having a strong oxidizing power. When organic substances such as odor components and bacteria come into contact therewith, they are oxidized by taking electrons from the organic substances. The organic matter having a large molecular weight continues to react until it finally becomes mainly water and carbon dioxide. Thereby, since the organic substance adhering to the heat exchanger is decomposed, it is antibacterial and deodorized.

  This molding of the hydrophilic layer and the protective layer will be described more specifically. The conventional hydrophilic layer and protective layer are prepared by diluting a mixture solution for forming both with water and applying it to the surface of the aluminum material, and eluting the protective layer components on the surface during sintering. How to make Therefore, in this embodiment, instead of this water, the mixed solution of the hydrophilic layer and the protective layer is diluted with an aqueous catalyst solution and applied to the surface of the aluminum material, and this mixed solution is baked on the aluminum material 10 to deodorize the antibacterial material. The hydrophilic layer 11 containing much 14 and the protective layer 13 containing few deodorizing antibacterial materials 14 are formed. In this way, good productivity can be maintained by forming the hydrophilic layer 11 and the protective layer 13 in basically the same process as before. And as a result of applying and baking to the aluminum raw material surface as a liquid mixture which added catalyst aqueous solution, as shown in FIG. 2, 80% or more of deodorizing antibacterial materials 14 remain in a hydrophilic layer, and it distributes densely on the surface side. It was confirmed. This is because the catalyst is more easily dispersed in the component of the hydrophilic layer 11 than the component of the protective layer 13 and moves to the upper layer of the hydrophilic layer 13 together with the evaporated water when fired after being applied to the surface of the aluminum material. Therefore, the deodorizing antibacterial material 14 can be efficiently added to the hydrophilic layer 11 without increasing the number of processing steps.

  As shown in FIG. 2, many catalyst particles are distributed in the vicinity of the boundary between the hydrophilic layer 11 and the protective layer 13. As described above, when the heat exchanger 5 is incorporated in an air conditioner and actually used, the heat exchanger 5 is washed away by dew generated when the heat exchanger 5 acts as an evaporator. Since the surface of the hydrophilic layer 11 remaining after the protective layer 13 is flowed is a boundary between the two layers, a relatively large amount of catalyst is exposed on the surface of the hydrophilic layer 11, and as a result, the catalyst is separated from air. Since the touching area increases, the catalytic action can be sufficiently exerted.

  After forming the aluminum fin 5b in which the hydrophilic layer 12 and the protective layer 13 are formed on the aluminum material 10, a pipe through hole, a stepped portion, or the like is press-formed in the aluminum fin 5b. A copper pipe 5a is passed through the aluminum fins 5b and assembled as a heat exchanger 5. In the case of applying the photocatalyst, it is easier to manufacture it by applying it to the fin material in advance than applying it to the finished heat exchanger.

  Next, the relationship between the hydrophilic performance, which is the original performance of the hydrophilic layer 11, and the addition amount of the deodorizing antibacterial material 14 will be described with reference to FIG. FIG. 3 is a diagram showing the relationship between the addition amount of the deodorizing antibacterial material used in this example and the contact angle.

  In order to obtain the relationship shown in FIG. 3, aluminum fins having different amounts of addition of the deodorizing antibacterial material 14 used in the present example were manufactured, and the hydrophilic performance was evaluated by the contact angle of water droplets. In FIG. 3, 15 (solid line) shows the initial hydrophilic performance of the produced aluminum fin, and 16 (dotted line) shows the hydrophilicity after the durability test in which the produced aluminum fin is immersed in running water for 24 hours. As a result, it was confirmed that the initial hydrophilic performance 15 did not affect the addition of the deodorizing antibacterial material 15. Further, it was found that the hydrophilicity 16 after the durability test tends to improve the hydrophilic performance. Therefore, it can be said that the deodorizing antibacterial material 14 of the present embodiment is a hydrophilic performance improving material. This is because the deodorizing antibacterial material 14 can form a colloid in an aqueous solution. That is, the fact that the deodorizing antibacterial material 14 can form a colloid means that the deodorizing antibacterial material 14 of this embodiment has a hydrophilic property.

  Next, the relationship between the deodorizing performance and the addition amount of the deodorizing antibacterial material 14 will be described with reference to FIG. FIG. 4 is a graph showing the relationship between the amount of deodorized antibacterial material used in this example and the ammonia deodorization rate.

  In order to obtain the relationship shown in FIG. 4, 10 cm square aluminum fins with different amounts of addition of the deodorizing antibacterial material 14 used in the present example were made as prototypes, and these aluminum fins and a bad odor are representative in a commercially available 40 L desiccator. 30 ppm of ammonia was added, and the concentration change in the container after 60 minutes was calculated as the deodorization rate. From FIG. 4, it was found that the deodorizing performance is improved as the addition amount of the deodorizing antibacterial material 14 is increased and the deodorizing performance is improved at 40% or more.

  Next, FIG. 5 shows the transition of the wear state of the mold after the aluminum fin punching mold test conducted to confirm the influence on the mold. This is a prototype of an aluminum fin in which the amount of deodorizing antibacterial material 14 added is changed, and a hole through which a copper pipe is passed is confirmed, and the wear state of the mold at this time is confirmed. In FIG. 5, “◯” indicates that no wear is observed, and “×” indicates that the mold is worn and the life of the mold is shortened. From FIG. 5, it was found that the addition amount of the deodorizing antibacterial material 14 is preferably 20% or less in order to add the deodorizing antibacterial function when the aluminum fin is processed and processed.

Next, FIG. 6 shows a result of producing a heat exchanger for an air conditioner to which 10% of the deodorizing antibacterial material 14 is added and confirming the deodorizing performance of ammonia when the air conditioner is operated in a 1 m ³ sealed container. 18 is the ammonia remaining rate characteristic due to natural decay in the sealed container, 19 is the ammonia remaining rate characteristic without the deodorizing antibacterial material, and 20 is the ammonia remaining rate characteristic by the air conditioner equipped with the heat exchanger added with 10% of the deodorizing antibacterial material. Show.

  As can be seen from FIG. 6, the ammonia remaining rate characteristic 19 using the heat exchanger without deodorizing antibacterial material becomes 40% after 60 minutes, whereas the heat exchanger having 10% added deodorizing antibacterial material 14 It was confirmed that the residual rate characteristic 20 using NO reached a residual rate of 40% in 10 minutes. By adding 10% of the deodorizing antibacterial material, it was confirmed that a high deodorizing function could be added to the air conditioner.

  According to the present embodiment, the heat exchanger 5 includes a copper pipe 5A through which a refrigerant flows, and aluminum fins 5b in which a large number of the copper pipes 5a are arranged to penetrate the copper pipe 5a and the hydrophilic layer 12 is formed on the aluminum material 10. In this embodiment, the nanoparticle deodorizing antibacterial material 14 in which zinc is supported on titanium oxide is added in the hydrophilic layer 12 so that the surface side is more densely distributed than the aluminum material side. Current corrosion can be prevented, and sufficient deodorizing performance can be obtained with a slight amount of light while improving the adhesion and hydrophilicity of the hydrophilic layer 12.

  In addition, according to the present invention, the heat exchanger 5 includes the copper pipe 5a for flowing the refrigerant therein, and the aluminum fins 5b in which a large number of the copper pipes 5a are arranged to penetrate the aluminum pipe 10 and the hydrophilic layer 12 is formed on the aluminum material 10. In this manufacturing method, an aqueous solution containing nanoparticle deodorizing antibacterial material 14 in which zinc is supported on titanium oxide is mixed with a hydrophilic layer solution, and this mixed solution is baked on the surface of the aluminum material 10 so that the deodorizing antibacterial material 14 is made of aluminum. Since the hydrophilic layer 12 that is densely distributed from the material side to the surface side is formed, while being able to prevent local current corrosion due to condensation at low cost and improving the adhesion and hydrophilicity of the hydrophilic layer 12, Sufficient deodorization performance can be obtained with little light.

It is a longitudinal cross-sectional view of the indoor unit of the air conditioner to which the heat exchanger of one Example of this invention is applied. It is a cross-sectional enlarged schematic diagram of the surface part of the heat exchanger 5 of a present Example. It is a figure which shows the relationship between the addition amount of a deodorizing antibacterial material used for a present Example, and a contact angle. It is a figure which shows the relationship between the addition amount of the deodorizing antibacterial material used for a present Example, and ammonia deodorizing rate. It is a figure which shows the relationship between the addition amount of the deodorizing antibacterial material used for a present Example, and metal mold | die wear. It is a characteristic view of the ammonia residual rate of the heat exchanger containing the heat exchanger of a present Example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Housing, 1a ... Suction inlet, 1b ... Outlet, 2 ... Cosmetic frame, 3 ... Base frame, 4 ... Dew tray, 5 ... Heat exchanger, 5a ... Copper pipe, 5b ... Aluminum fin, 6 ... Ventilation fan , 7 ... Air filter, 8 ... Pre-filter, 9 ... Wind direction blade, 10 ... Aluminum material, 11 ... Hydrophilic layer, 12 ... Ground treatment layer, 13 ... Protective layer, 14 ... Deodorizing antibacterial material, 15 ... Initial contact angle, 16 ... contact angle after end of durability test, 17 ... ammonia deodorization rate 60 minutes after start of deodorization test, 18 ... ammonia residual rate characteristic of natural decay, 19 ... ammonia residual rate characteristic without deodorizing antibacterial material, 20 ... deodorizing antibacterial processed material A characteristic of residual ammonia rate, 50 ... indoor unit.

Claims (9)

Aluminum fins in which a large number of copper pipes flow through the inside, and the copper pipes are arranged side by side and a hydrophilic layer is formed on the aluminum material, and a protective layer is formed on the surface of the hydrophilic layer to be washed away with condensed water. In a heat exchanger with
The hydrophilic layer and the protective layer have a nanoparticle deodorizing antibacterial material in which zinc is supported on titanium oxide ,
The hydrophilic layer surface side densely distributed than the aluminum material side the deodorizing antibacterial material,
The heat exchanger according to claim 1, wherein the deodorizing antibacterial material is distributed more in the hydrophilic layer than in the protective layer . 2. The heat exchanger according to claim 1, wherein the protective layer is mainly made of polyethylene glycol . 3. The heat exchanger according to claim 1 , wherein 80% or more of the deodorizing antibacterial material added to the hydrophilic layer and the protective layer is distributed in the hydrophilic layer. 4. The heat exchanger according to claim 1 or 2 , wherein an average particle size of the deodorizing antibacterial material is about 10 nm. The heat exchanger according to claim 1 or 2 , wherein the deodorizing antibacterial material is added to the hydrophilic layer in an amount of 2 to 40% by weight. Aluminum fins in which a large number of copper pipes flow through the inside, and the copper pipes are arranged side by side and a hydrophilic layer is formed on the aluminum material, and a protective layer is formed on the surface of the hydrophilic layer to be washed away with condensed water. In a method of manufacturing a heat exchanger comprising:
By applying a mixture of an aqueous solution containing a nanoparticle deodorizing antibacterial material in which zinc is supported on titanium oxide , a hydrophilic layer solution, and a protective layer solution to the surface of the aluminum material and firing ,
Forming the hydrophilic layer containing a lot of the deodorizing antibacterial material and the protective layer containing a small amount of the deodorizing antibacterial material
Method of manufacturing a heat exchanger, characterized in that the deodorizing antibacterial material to form the hydrophilic layer surface side densely distributed than the aluminum material side. The method of manufacturing a heat exchanger according to claim 6, wherein the protective layer is mainly made of polyethylene glycol . The method of manufacturing a heat exchanger according to claim 6 or 7, the manufacturing method of the heat exchanger, which comprises using the deodorant antimicrobial material having an average particle diameter of about 10nm as the deodorizing antibacterial material. In the manufacturing method of the heat exchanger of Claim 6 or 7 , on the said aluminum raw material by the said liquid mixture using the said hydrophilic layer solution in which the said deodorizing antibacterial material consists of a component which is easier to disperse | distribute than the said protective layer solution. After forming a hydrophilic layer and a protective layer , the said copper pipe is penetrated and assembled in the said aluminum fin, The manufacturing method of the heat exchanger characterized by the above-mentioned.

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