Insulated pipe for vehicle refrigerant and method for manufacturing same

Abstract

The invention provides a heat insulation pipe for a vehicle refrigerant and a manufacturing method of the heat insulation pipe. The heat insulation pipe is endowed with heat insulation performance and can maintain the shape during manufacturing and use. This insulated pipe (1) for a vehicle refrigerant has a flow path (4) for a vehicle refrigerant, and is provided with: a flow path formation layer (2) in which the flow path (4) is defined and formed; and a heat-insulating layer (3) that covers the flow-path-forming layer (2) from the outside in the radial direction, the porosity of the flow-path-forming layer (2) being less than 20%, and the porosity of the heat-insulating layer (3) being greater than or equal to 20% and less than 80%.

Description

Technical Field

[0001] The present invention relates to a thermally insulated tube for vehicle refrigerant which is mounted on a vehicle and has a flow path for a vehicle refrigerant, a method for manufacturing the thermally insulated tube for vehicle refrigerant, and a thermally insulated tube for vehicle refrigerant obtained by the manufacturing method. Background Art

[0002] If the temperature of the vehicle-mounted devices such as the motor and the vehicle driving battery mounted on the vehicle becomes too high or too low, it is difficult to fully exert their capabilities. A heat exchanger for maintaining such vehicle-mounted devices at an appropriate temperature is mounted on a common vehicle. The vehicle refrigerant flows through the heat exchanger, and the heat exchanger exchanges heat with the vehicle-mounted devices via the vehicle refrigerant.

[0003] The heat exchanger is connected to a vehicle refrigerant container, an infusion pump, etc. via a vehicle refrigerant insulated pipe. It can be said that the vehicle refrigerant insulated pipe has a flow path for the vehicle refrigerant communicating with the heat exchanger, the container, the infusion pump, etc.

[0004] It is conceivable that in order to maintain a vehicle-mounted device at an appropriate temperature, it is more effective to maintain the vehicle refrigerant that performs heat exchange with the vehicle-mounted device within a predetermined temperature range. It is conceivable that in order to maintain the vehicle refrigerant within a predetermined temperature range, it is more effective to use a vehicle refrigerant insulation pipe that imparts thermal insulation properties to the vehicle refrigerant pipe through which the vehicle refrigerant circulates.

[0005] As one of the methods for imparting heat insulating properties to a vehicle refrigerant pipe to form an insulated vehicle refrigerant pipe, it is conceivable to select a heat insulating material as the material of the insulated vehicle refrigerant pipe.

[0006] Patent Document 1 introduces a pipe for circulating a high-temperature chemical solution in a semiconductor manufacturing apparatus. Patent Document 1 describes that the pipe is formed of a porous tube to maintain the temperature of the chemical solution.

[0007] Patent Document 1 introduces a structure including a porous portion made of polytetrafluoroethylene (PTFE) and an acid-base indicator supported on the porous portion as a specific example of the above-mentioned porous tube.

[0008] For reference, if an acidic or alkaline drug solution flowing through a porous tube leaks out, the drug solution reacts with an acid-base indicator and develops a color. Therefore, the porous tube has the advantages of being able to exert heat insulation performance and being able to easily detect a location in the porous tube where the drug solution has leaked out.

[0009] It is conceivable that if a vehicle refrigerant pipe is formed of the porous portion, a thermally insulated vehicle refrigerant pipe imparted with thermal insulation performance can be obtained.

[0010] Patent Document 1: Japanese Patent Application Publication No. 2022-143892

[0011] As described above, it is conceivable that if the vehicle refrigerant pipe is formed of the porous portion described in Patent Document 1, a thermally insulated vehicle refrigerant pipe imparted with thermal insulation performance can be obtained.

[0012] However, in order to facilitate connection with supporting components such as the above-mentioned heat exchanger, the vehicle refrigerant pipe is required to be connected with the supporting components with high strength in addition to the above-mentioned thermal insulation performance.

[0013] However, the porous part made of PTFE has low rigidity and strength, so it is difficult to maintain its shape. Therefore, the thermal insulation pipe for vehicle refrigerant formed by the porous part may have poor connection strength with the supporting parts.

[0014] In addition, the vehicle refrigerant insulation pipe may need to be formed into a bent shape according to the configuration of the vehicle-mounted device, heat exchanger, other vehicle-mounted device, etc., which is the object of heat exchange. However, the vehicle refrigerant insulation pipe formed of a porous portion has poor rigidity and strength, and therefore may not maintain its shape during bending.

[0015] In addition, in order to allow the cooler or hotter refrigerant to flow inside the vehicle refrigerant insulation pipe, heat is also applied to the vehicle refrigerant insulation pipe itself. The heat may cause the vehicle refrigerant insulation pipe to deform or soften depending on the situation. As a result, it is also expected that the connection between the vehicle refrigerant insulation pipe and the supporting parts may be disconnected, making it difficult to maintain the above-mentioned bent shape.

[0016] Therefore, there is a need for a thermally insulated tube for vehicle refrigerant that is provided with thermal insulation performance and can maintain its shape during manufacture and use. Summary of the invention

[0017] The present invention has been made in view of the above circumstances, and an object to be solved is to provide a thermally insulated tube for vehicle refrigerant that has a thermal insulation property and can maintain its shape during manufacture and use.

[0018] One embodiment of the vehicle refrigerant insulation pipe of the present invention for solving the above-mentioned problems is as follows:

[0019] (1) A thermally insulated pipe for vehicle refrigerant, comprising a flow path for vehicle refrigerant, wherein:

[0020] The vehicle refrigerant heat insulation pipe comprises: a flow path forming layer which divides the flow path inside; and a heat insulation layer which covers the flow path forming layer from the radially outer side.

[0021] The porosity of the flow path forming layer is less than 20%, and the porosity of the heat insulating layer is greater than or equal to 20% and less than 80%.

[0022] Another aspect of the vehicle refrigerant insulation pipe of the present invention which solves the above-mentioned problems is as follows:

[0023] (2) A thermally insulated pipe for vehicle refrigerant, comprising a flow path for vehicle refrigerant, wherein:

[0024] The vehicle refrigerant heat insulation pipe comprises: a flow path forming layer which divides the flow path inside; and a heat insulation layer which covers the flow path forming layer from the radially outer side.

[0025] The Young's modulus of the flow path forming layer is greater than or equal to 1000 MPa and less than or equal to 4000 MPa, and the Young's modulus of the heat insulating layer is less than 1000 MPa.

[0026] One aspect of the method for manufacturing a thermally insulated tube for a vehicle refrigerant of the present invention that solves the above-mentioned problems is as follows:

[0027] (3) A method for manufacturing a thermally insulated tube for vehicle refrigerant, the method being a method for manufacturing a tube having a flow path for vehicle refrigerant and comprising: a flow path forming layer which divides the flow path internally; and a thermal insulating layer which covers the flow path forming layer from the radially outer side, wherein:

[0028] The manufacturing method of the insulated pipe for vehicle refrigerant has the following extrusion molding process, that is, using the flow path forming material as the material of the flow path forming layer and the thermal insulation material as the material of the thermal insulation layer, the flow path forming layer having a porosity less than 20% and the thermal insulation layer having a porosity greater than or equal to 20% and less than 80% are extruded.

[0029] Another aspect of the method for manufacturing the thermal insulation tube for vehicle refrigerant of the present invention which solves the above-mentioned problems is as follows:

[0030] (4) A method for manufacturing a thermally insulated tube for vehicle refrigerant, the method being a method for manufacturing a tube having a flow path for vehicle refrigerant and comprising: a flow path forming layer which divides the flow path internally; and a thermal insulation layer which covers the flow path forming layer from the radially outer side, wherein:

[0031] The manufacturing method of the insulated pipe for vehicle refrigerant has the following extrusion molding process, that is, using the flow path forming material as the material of the flow path forming layer and the insulation material as the material of the insulation layer, the flow path forming layer with a Young's modulus greater than or equal to 1000MPa and less than or equal to 4000MPa and the insulation layer with a Young's modulus less than 1000MPa are extruded.

[0032] Another aspect of the vehicle refrigerant insulation pipe of the present invention which solves the above-mentioned problems is as follows:

[0033] (5) A thermally insulated pipe for vehicle refrigerant, wherein the thermally insulated pipe for vehicle refrigerant is obtained by extrusion molding using the manufacturing method of (3) above.

[0034] Another aspect of the vehicle refrigerant insulation pipe of the present invention which solves the above-mentioned problems is as follows:

[0035] (6) A thermally insulated pipe for vehicle refrigerant, wherein the thermally insulated pipe for vehicle refrigerant is obtained by extrusion molding using the manufacturing method of (4) above.

[0036] Effects of the Invention

[0037] The insulated tube for vehicle refrigerant of the present invention is a heat-insulating tube for vehicle refrigerant that has heat-insulating properties and can maintain its shape during manufacture and use. In addition, according to the manufacturing method of the insulated tube for vehicle refrigerant of the present invention, it is possible to provide a heat-insulating tube for vehicle refrigerant that has heat-insulating properties and can maintain its shape during manufacture and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is an explanatory diagram schematically illustrating the appearance of the thermal insulation pipe for a vehicle according to the first embodiment.

[0039] Figure 2 This is an explanatory diagram schematically illustrating a radial cross section of the thermal insulation pipe for a vehicle according to the first embodiment.

[0040] Figure 3 This is an explanatory diagram schematically illustrating an axial cross section of the thermal insulation pipe for a vehicle according to the first embodiment.

[0041] Figure 4 This is an explanatory diagram schematically illustrating a radial cross section of a thermal insulation pipe for a vehicle according to a second embodiment.

[0042] Figure 5 This is an explanatory diagram schematically illustrating an axial cross section of a thermal insulation pipe for a vehicle according to a second embodiment. DETAILED DESCRIPTION

[0043] Next, the thermally insulated tube for vehicle refrigerant and the method for producing the same according to the present invention will be described with reference to specific examples.

[0044] Hereinafter, unless otherwise specified, the above-mentioned embodiment (1) of the insulated tube for vehicle refrigerant of the present invention may be referred to as the insulated tube for vehicle refrigerant of the first embodiment. Also, unless otherwise specified, the above-mentioned embodiment (2) of the insulated tube for vehicle refrigerant of the present invention may be referred to as the insulated tube for vehicle refrigerant of the second embodiment. Furthermore, the insulated tube for vehicle refrigerant of the first embodiment and the insulated tube for vehicle refrigerant of the second embodiment may be collectively referred to as the insulated tube for vehicle refrigerant of the present invention.

[0045] In addition, unless otherwise specified, the above-mentioned aspect (3) in the method for manufacturing a thermally insulated tube for a vehicle refrigerant of the present invention may be referred to as the manufacturing method of the third aspect. Unless otherwise specified, the above-mentioned aspect (4) in the method for manufacturing a thermally insulated tube for a vehicle refrigerant of the present invention may be referred to as the manufacturing method of the fourth aspect. Furthermore, the manufacturing method of the third aspect and the manufacturing method of the fourth aspect may be collectively referred to as the manufacturing method of the present invention.

[0046] In addition, unless otherwise stated, the numerical range "x to y" described in this specification includes the lower limit x and the upper limit y in the range. Moreover, the numerical range may be formed by arbitrarily combining the above upper limit and lower limit values ​​and the numerical values ​​listed in the embodiment. Furthermore, the numerical value arbitrarily selected from the numerical range may be set as the upper limit and lower limit.

[0047] The insulated tube for vehicle refrigerant of the present invention is a tube having a flow path for vehicle refrigerant. The insulated tube for vehicle refrigerant of the present invention can also be referred to as a tube having the flow path inside.

[0048] The refrigerant flowing through the flow path may be a liquid or a gas as long as it is a fluid flowing through the flow path of the vehicle refrigerant insulation pipe and can exchange heat with a target vehicle-mounted device.

[0049] As a specific refrigerant, a substance called long-term coolant (LLC) in which various additives such as an anticorrosive agent, a lubricant, and a rust inhibitor are added to water can be exemplified, but the refrigerant is not limited to this.

[0050] The refrigerant may also be referred to as a heat exchange medium, a heat medium, or a heat medium.

[0051] The vehicle refrigerant insulation pipe of the present invention comprises a flow path forming layer and a heat insulating layer. The flow path forming layer is a portion that divides and forms the flow path inside, and can also be called a layer adjacent to the flow path. On the other hand, the heat insulating layer is a portion that covers the flow path forming layer from the radial outside.

[0052] In the vehicle refrigerant insulated pipe of the present invention, the flow path forming layer is a portion that defines and forms the flow path and serves as a connection portion for connection with a supporting component such as a heat exchanger, etc. Furthermore, the heat insulating layer is a portion that serves to exert heat insulating performance.

[0053] In the first aspect of the thermally insulated tube for vehicle refrigerant, the flow path forming layer has a porosity of less than 20%, and the thermal insulating layer has a porosity of 20% or more and less than 80%.

[0054] According to the first embodiment of the thermal insulation tube for vehicle refrigerant, by setting the porosity of the flow path forming layer to less than 20%, the strength and rigidity of the flow path forming layer can be improved, and the shape can be easily maintained during manufacturing and use. Moreover, as a result, the first embodiment of the thermal insulation tube for vehicle refrigerant can appropriately maintain its shape during bending and use, and the connection strength with respect to the supporting parts is improved.

[0055] On the other hand, in the thermally insulated tube for vehicle refrigerant of the second aspect, the Young's modulus of the flow path forming layer is greater than or equal to 1000 MPa and less than or equal to 4000 MPa, and the Young's modulus of the thermal insulating layer is less than 1000 MPa.

[0056] According to the thermal insulation pipe for vehicle refrigerant of the second aspect, a structure having a higher Young's modulus than the thermal insulation layer, in other words, a structure having high rigidity and being difficult to deform is selected as the flow path forming layer.

[0057] Specifically, regarding the second embodiment of the thermal insulation tube for vehicle refrigerant, the Young's modulus of the flow path forming layer is determined to be greater than or equal to 1000 MPa and less than or equal to 4000 MPa. Such a flow path forming layer is difficult to deform sufficiently to maintain its shape, and can be elastically deformed to a degree that can be connected to a supporting component. As a result, the second embodiment of the thermal insulation tube for vehicle refrigerant also appropriately maintains its shape during bending and use, and can also improve the connection strength with respect to the supporting component.

[0058] The manufacturing method of the present invention is a method for manufacturing a pipe having the above-mentioned flow path forming layer and heat insulating layer. In the manufacturing method of the present invention, the vehicle refrigerant heat insulating pipe is extruded. More specifically, the manufacturing method of the present invention has the following extrusion molding step, that is, the flow path forming layer and the heat insulating layer are extruded using the flow path forming material as the material of the flow path forming layer and the heat insulating material as the material of the heat insulating layer.

[0059] The above-mentioned insulated tube for vehicle refrigerant of the present invention comprises: a flow path forming layer having a flow path for vehicle refrigerant, the flow path being divided and formed inside; and a heat insulating layer covering the flow path forming layer from the radially outer side. For example, the insulated tube for vehicle refrigerant can be manufactured by winding and bonding the heat insulating layer on the radially outer side of the flow path forming layer prepared in advance.

[0060] However, the outer shape and volume of the winding-bonding type vehicle refrigerant insulation tube obtained by winding and bonding the insulation layer to the radially outer side of the pre-prepared flow path forming layer are increased. The vehicle refrigerant insulation tube installed in the vehicle is often required to be compact, and sometimes the above-mentioned winding-bonding type vehicle refrigerant insulation tube cannot cope with it.

[0061] In addition, regarding the above-mentioned winding and bonding type vehicle refrigerant thermal insulation tube, depending on its shape, material combination, etc., the flow path forming layer and the heat insulating layer may not be bonded with sufficient strength, making it difficult to maintain the shape of the vehicle refrigerant thermal insulation tube.

[0062] Furthermore, in this case, for example, it is also expected that the flow path forming layer and the heat insulating layer may be partially or entirely separated.

[0063] In the production method of the present invention, a thermal insulation pipe for a vehicle refrigerant is produced by an extrusion molding method.

[0064] More specifically, as described above, the manufacturing method of the present invention includes an extrusion molding step of extruding the flow path forming layer and the heat insulating layer using a flow path forming material as a material of the flow path forming layer and a heat insulating material as a material of the heat insulating layer.

[0065] Regarding the insulated vehicle refrigerant tube manufactured by the extrusion molding method, that is, the insulated vehicle refrigerant tube obtained by the manufacturing method of the present invention, in order to weld the flow path forming layer and the heat insulating layer to make them firmly joined, the separation of the flow path forming layer and the heat insulating layer is fully suppressed.

[0066] In addition, according to the manufacturing method of the present invention having the above-mentioned extrusion molding step, it is possible to obtain a thermally insulated tube for vehicle refrigerant or a precursor thereof in which the flow path forming layer and the heat insulating layer are fused together through a single step such as the extrusion molding step. That is, according to the manufacturing method of the present invention, it is possible to easily manufacture a thermally insulated tube for vehicle refrigerant in which the flow path forming layer and the heat insulating layer are firmly bonded together.

[0067] Furthermore, according to the extrusion molding, compared with the method of manufacturing the above-mentioned winding-bonding type vehicle refrigerant insulation tube, that is, the method of winding and bonding the insulation layer to the radially outer side of the previously prepared flow path forming layer, a compact insulation layer without waste can be formed. Therefore, the vehicle refrigerant insulation tube obtained by the manufacturing method of the present invention also has the advantage of being compact compared with the above-mentioned winding-bonding type vehicle refrigerant insulation tube.

[0068] However, in the production method of the third aspect of the present invention, a flow path forming layer having a porosity of less than 20% and a heat insulating layer having a porosity of 20% or more and less than 80% are formed in the extrusion molding step.

[0069] According to the manufacturing method of the third aspect, the thermal insulation tube for vehicle refrigerant of the first aspect can be easily manufactured.

[0070] In addition, the insulated tube for vehicle refrigerant obtained by the manufacturing method of the third embodiment, that is, the insulated tube for vehicle refrigerant of the above-mentioned fifth embodiment, is compact, and like the insulated tube for vehicle refrigerant of the above-mentioned first embodiment, its shape can be properly maintained during bending and use, and the connection strength relative to the supporting parts is also improved.

[0071] In the manufacturing method of the fourth aspect of the present invention, in the extrusion molding step, a flow path forming layer having a Young's modulus of 1000 MPa or more and 4000 MPa or less and a heat insulating layer having a Young's modulus of less than 1000 MPa are formed.

[0072] According to the manufacturing method of the fourth aspect, the thermal insulation tube for vehicle refrigerant of the second aspect can be easily manufactured.

[0073] In addition, the insulated tube for vehicle refrigerant obtained by the manufacturing method of the fourth embodiment, that is, the insulated tube for vehicle refrigerant of the above-mentioned sixth embodiment, is compact, and like the insulated tube for vehicle refrigerant of the above-mentioned second embodiment, its shape can be properly maintained during bending and use, and the connection strength relative to the supporting parts is also improved.

[0074] Hereinafter, the thermally insulated tube for vehicle refrigerant and the method for producing the same according to the present invention will be described with respect to each component.

[0075] The thermally insulated tube for vehicle refrigerant of the present invention comprises a flow path forming layer and a thermal insulating layer.

[0076] The flow path forming layer is formed into a shape having a flow path inside, that is, a cylindrical shape. In addition, the flow path forming layer is a portion of the vehicle refrigerant insulation pipe of the present invention that can divide and form a flow path and is elastically deformed to a degree that can be connected to a supporting component. The portion of the supporting component connected to the flow path forming layer has a flow path for the refrigerant to flow. If the flow path forming layer and the supporting component are connected, the flow path of the supporting component is connected to the flow path of the flow path forming layer.

[0077] As a method for connecting the flow path forming layer and the supporting component, specifically, it is preferred to adopt a method in which the end of the supporting component is inserted into the flow path of the flow path forming layer so that the flow path of the flow path forming layer and the flow path of the supporting component are connected, or a method in which the end of the flow path forming layer is inserted into the flow path of the supporting component so that the flow path of the flow path forming layer and the flow path of the supporting component are connected.

[0078] The flow path forming layer may be of an elastically deformable structure or a non-elastically deformable structure. In order to maintain the connection between the flow path forming layer and the supporting component in a preferred state, it is preferable that the flow path forming layer be deformable to a certain extent.

[0079] Therefore, as the material of the flow path forming layer, for example, a material that does not elastically deform, such as metal or ceramic, may be selected, but it is preferable to select a material that can elastically deform, such as resin, rubber, or elastomer.

[0080] Here, the vehicle refrigerant insulation pipe of the present invention is preferably lightweight for easy installation in a vehicle. From this viewpoint, it can also be said that various resins, rubbers or elastomers are preferably used as a single substance or in combination as a material for the flow path forming layer.

[0081] In addition, as the material of the flow path forming layer, it is preferred to use a structure in which one or more selected from various resins, rubbers or elastomers is used as a base material and a filler such as metal or glass is added to the base material. In this case, various functionalities derived from the filler can be imparted to the flow path forming layer.

[0082] Specific materials suitable for the flow path forming layer include polypropylene (PP), polyphenylene sulfide (PPS), and polyamide (PA). As described above, the above materials can be used alone or in combination. Alternatively, at least one of the above materials and other materials can be used together.

[0083] The flow path forming layer is preferably structured to have a certain degree of high rigidity. As described above, regarding the thermal insulation pipe for vehicle refrigerant of the second embodiment, the flow path forming layer has a Young's modulus of 1000 MPa or more and 4000 MPa or less.

[0084] The flow path forming layer having a Young's modulus within the above range is difficult to deform sufficiently to maintain its shape, and can be elastically deformed to a degree that allows connection with a supporting component. Therefore, regarding the first embodiment of the thermal insulation pipe for vehicle refrigerant, it is also preferred that the Young's modulus of the flow path forming layer is greater than or equal to 1000 MPa and less than or equal to 4000 MPa.

[0085] Furthermore, in order to provide the flow path forming layer with a certain degree of rigidity that can withstand use as a flow path for vehicle refrigerant and can exhibit a certain degree of rigidity, it is preferable to reduce the porosity of the flow path forming layer.

[0086] In the thermal insulation tube for vehicle refrigerant of the first aspect, the porosity of the flow path forming layer is set to less than 20%.

[0087] Regarding the second embodiment of the vehicle refrigerant insulation pipe, for the same reason as above, it is preferable to reduce the voids in the flow path forming layer. Specifically, it is preferable that the void ratio of the flow path forming layer is less than 25%, less than 20%, or less than 15%.

[0088] In addition, there is no particular lower limit for the porosity, and the porosity of the flow path forming layer may be 0%.

[0089] In this specification, the void ratio can be expressed, for example, based on the percentage using the true density and the apparent density, that is, based on the following formula [1]. The apparent density can be measured by the liquid weighing method specified in JIS K 0061. On the other hand, the true density can be measured by the pycnometer method using a Gay-Lussac type pycnometer specified in JIS K 0061, the pycnometer method using a dial, or the pycnometer method using an Ostwald pycnometer.

[0090] Void ratio (%) = 100 - {100 × (apparent density / true density)}…[1]

[0091] When the porosity of the flow path forming layer exceeds 0%, that is, when the flow path forming layer is a porous body having pores, the flow path forming layer may be a continuous foam type porous body in which a plurality of pores are interconnected, or an independent foam type porous body in which each pore is independent of another. Depending on the case, a gas, liquid, or solid different from the main material that defines and forms the pores may enter the pores.

[0092] When the flow channel forming layer is a porous body, the average pore diameter of the flow channel forming layer is preferably in the range of 10 μm to 600 μm. As a method for measuring the average pore diameter, for example, the following method can be selected.

[0093] First, cut a section of the flow path forming layer at an arbitrary position. In this section, set an arbitrary 5 mm × 5 mm area. For all pores in this area, measure their maximum diameters with the naked eye or under a microscope. The maximum diameter of the pores mentioned here refers to the maximum value of the distance between two parallel tangents to the pores. Just calculate the average value of the maximum diameters of the pores in the above area and set it as the average pore diameter.

[0094] In order to maintain the shape of the vehicle refrigerant insulation tube during use, it is preferable to select a material with a relatively small linear expansion coefficient as the material of the flow path forming layer. The flow path forming layer with a small linear expansion coefficient has a small deformation amount due to temperature change.

[0095] Specifically, the linear expansion coefficient of the material of the flow path forming layer is preferably in the range of 5 to 11×10 -5 ( / ℃) range.

[0096] The heat insulating layer is a layer covering the flow path forming layer from the radially outer side, and is a portion responsible for heat insulation in the thermal insulation pipe for vehicle refrigerant of the present invention.

[0097] By forming the heat insulating layer from a porous body having fine pores, it is possible to impart excellent heat insulating properties to the heat insulating layer. In the first embodiment of the heat insulating tube for vehicle refrigerant, the porosity of the heat insulating layer is set to be greater than or equal to 20% and less than 80%.

[0098] In addition, regarding the insulation layer of the vehicle refrigerant insulation pipe of the second method, based on the reasons mentioned above, it is also preferably a porous body, and its porosity is preferably greater than or equal to 15% and less than 90%, greater than or equal to 20% and less than 80%, or greater than or equal to 25% and less than 70%.

[0099] Furthermore, in the thermally insulated tube for vehicle refrigerant of the first aspect, the Young's modulus of the thermal insulation layer is determined to be less than 1000 MPa.

[0100] Here, the heat insulating layer is different from the flow path forming layer and is not a part that is required to function as a connection portion with respect to the supporting component. Therefore, the Young's modulus of the heat insulating layer can be significantly lower than that of the flow path forming layer. From this viewpoint, as examples of the range of the Young's modulus of the heat insulating layer, 0.5 MPa or more and 50 MPa or less, 0.5 MPa or more and 10 MPa or less, and 0.5 MPa or more and 5 MPa or less can be shown.

[0101] The heat insulating layer may cover the entire flow path forming layer without omission, or may cover only a portion of the flow path forming layer. For example, in the vehicle refrigerant insulation pipe of the present invention, one or both axial ends of the flow path forming layer may not be covered by the heat insulating layer but may be exposed.

[0102] Furthermore, as described above, the heat insulating layer may cover the entire flow path forming layer or only a portion thereof, but it is more preferable that the heat insulating layer covers a larger portion of the surface of the flow path forming layer.

[0103] Specifically, when the surface area of ​​the flow path forming layer is set to 100%, it is preferred that the heat insulating layer covers 60% or more of the surface area, more preferably 70% or more of the surface area, and particularly preferably 80% or more of the surface area. In addition, the surface area of ​​the flow path forming layer mentioned here refers to the apparent surface area calculated assuming that the flow path forming layer has no pores.

[0104] The material of the heat insulating layer is preferably a material having heat insulating properties. In other words, as the material of the heat insulating layer, it is preferred to select a material with low thermal conductivity. Specifically, it is preferred that the thermal conductivity of the material of the heat insulating layer is less than or equal to 5 W / (m·℃), less than or equal to 3(m·℃), or less than or equal to 1(m·℃).

[0105] As the material of the heat insulating layer, it is particularly preferable to select resin, rubber, elastomer or the like.

[0106] Specific examples of the material of the heat insulating layer include olefin elastomer (TPO: Thermoplastic Olefinic Elastomer), styrene thermoplastic elastomer (TPS: Thermoplastic Styrenic Elastomer), PP, PPS, and PA. The heat insulating layer is preferably a foam made of these materials. In addition, the above materials may be used alone or in combination. Furthermore, at least one of the above materials and other materials may be used together.

[0107] When the heat insulating layer is a porous body, the heat insulating layer may be a continuous foam type porous body or an independent foam type porous body. As for the pores of the heat insulating layer, depending on the situation, a gas, liquid, or solid different from the main material that divides and forms the pores may enter.

[0108] When the heat-insulating layer is a porous body, the average pore diameter of the heat-insulating layer is the same as the average pore diameter of the flow path forming layer, and is preferably in the range of 10 μm to 600 μm.

[0109] When the heat insulating layer is a porous body, especially when the heat insulating layer is a foam body such as a foam resin, foam rubber, or foam elastomer, a layer with a relatively low porosity called a skin layer is sometimes formed on the surface of the heat insulating layer. The skin layer is a layer formed when the heat insulating layer is formed, and is formed by rapidly cooling a portion of the molding material injected into the molding die that contacts the mold surface of the molding die.

[0110] The skin layer is made of the same material as the heat insulating layer and is formed integrally with the heat insulating layer. The skin layer is formed in a layered form and has a lower porosity than other parts of the heat insulating layer as described above, but can be distinguished from the flow path forming layer in that it is very thin.

[0111] Specifically, it can be said that the thickness of the epidermis layer is less than or equal to 1 mm.

[0112] In contrast, the thickness of the heat insulating layer is preferably greater than the thickness of the flow path forming layer and greater than or equal to 1.5 times the thickness of the flow path forming layer. In addition, the thickness of the protective layer described later is preferably less than the thickness of the flow path forming layer and less than or equal to 0.8 times, less than or equal to 0.7 times, or less than or equal to 0.5 times the thickness of the flow path forming layer.

[0113] The insulated tube for vehicle refrigerant of the present invention may have a two-layer structure of a flow path forming layer and a heat insulating layer, but may also have a multi-layer structure of three or more layers including a protective layer in addition to the flow path forming layer and the heat insulating layer.

[0114] The protective layer is a layer covering the heat insulating layer from the radially outer side, and may be a single layer or a plurality of layers of two or more layers.

[0115] The heat insulating layer of the vehicle refrigerant heat insulating tube of the present invention has a larger porosity than the flow path forming layer or a smaller Young's modulus than the flow path forming layer, and can be said to be a layer more fragile than the flow path forming layer.

[0116] In the present invention, by providing a protective layer on the outer layer of the heat insulating layer, the heat insulating layer can be protected, and further the entire thermal insulation pipe for vehicle refrigerant can be protected.

[0117] The protective layer is preferably at least one of a layer having higher strength than the heat insulating layer, a layer having better weather resistance than the heat insulating layer, and a layer having better heat resistance than the heat insulating layer.

[0118] The protective layer may be any layer that can reinforce the heat insulating layer, and its material, structure, etc. are not particularly limited, but the porosity of the protective layer is preferably lower than that of the heat insulating layer. Specifically, the porosity of the protective layer is preferably less than 20%.

[0119] The protective layer may cover the entire surface of the heat insulating layer from the outside, or may cover only a portion of the surface of the heat insulating layer from the outside. In order to protect the heat insulating layer with higher reliability by the protective layer, it is more preferable that the protective layer covers a larger portion of the surface of the heat insulating layer.

[0120] Specifically, when the surface area of ​​the heat insulating layer is set to 100%, it is preferred that the protective layer covers 60% or more, more preferably 70% or more, and particularly preferably 80% or more. In addition, the surface area of ​​the heat insulating layer mentioned here refers to the apparent surface area calculated when it is assumed that the heat insulating layer has no pores.

[0121] As the material of the protective layer, for example, at least one selected from PP, PPS, and PA can be selected similarly to the flow path forming layer. Furthermore, at least one of the above materials and other materials can be used together. Preferably, the material of the protective layer is different from the material of the heat insulating layer.

[0122] Next, the thermally insulated tube for vehicle refrigerant and the method for producing the same according to the present invention will be described with reference to specific examples.

[0123] (Example 1)

[0124] The insulated tube for vehicle refrigerant of Example 1 is the insulated tube for vehicle refrigerant of the first mode and the insulated tube for vehicle refrigerant of the second mode. In addition, the manufacturing method of Example 1 is the manufacturing method of the third mode and the manufacturing method of the fourth mode. Therefore, it can also be said that the insulated tube for vehicle refrigerant of Example 1 is the insulated tube for vehicle refrigerant of the fifth mode and the insulated tube for vehicle refrigerant of the sixth mode.

[0125] exist Figure 1 , an explanatory diagram schematically illustrating the appearance of the vehicle thermal insulation pipe of Example 1 is shown. Figure 2 , which schematically illustrates a radial cross section of the vehicle heat insulation pipe of Example 1. Figure 3 Detailed Description of the Invention An explanatory diagram schematically illustrating an axial cross section of a thermal insulation tube for a vehicle according to Example 1 is shown in FIG.

[0126] The thermal insulation pipe 1 for vehicle refrigerant of the first embodiment is mounted on a vehicle (not shown) and constitutes a part of a flow path for vehicle refrigerant.

[0127] like Figure 1 As shown, the vehicle refrigerant insulation pipe 1 of the first embodiment is formed into a substantially cylindrical shape and is bent into a substantially L-shape.

[0128] One axial end 11 of the vehicle refrigerant insulation pipe 1 of the first embodiment is connected to a liquid infusion pump (not shown) as a supporting component via a joint 90 as an injection molded product, and the other end 12 is connected to a heat exchanger (not shown) as a supporting component.

[0129] like Figure 2 and Figure 3 As shown, the thermally insulated tube 1 for vehicle refrigerant according to the first embodiment is formed into a two-layer structure including a flow path forming layer 2 and a thermal insulating layer 3 .

[0130] The flow path forming layer 2 is made of PP and is formed into a substantially cylindrical shape. The interior of the flow path forming layer 2 formed into a substantially cylindrical shape is a cavity, and the interior functions as a flow path 4 for the vehicle refrigerant. That is, it can be said that the flow path forming layer 2 divides and forms the flow path 4 for the vehicle refrigerant.

[0131] The heat insulating layer 3 is made of foamed TPO and is formed into a substantially cylindrical shape that covers the entire flow path forming layer 2 from the radially outer side.

[0132] In the thermally insulated tube 1 for vehicle refrigerant of Example 1, the porosity of the flow path forming layer 2 is about 0%, and the porosity of the thermal insulating layer 3 is about 50%. The average pore size of the thermal insulating layer 3 is about 300 μm.

[0133] The Young's modulus of the flow path forming layer 2 is approximately 1350 MPa, and the Young's modulus of the heat insulating layer 3 is significantly lower than 1000 MPa.

[0134] In the vehicle refrigerant insulation tube 1 of Example 1, the linear expansion coefficient of the flow path forming layer 2 is 11×10 -5 ( / ℃).

[0135] The thickness of the flow path forming layer 2 is 1.5 mm, and the thickness of the heat insulating layer 3 is 3 mm. For reference, regarding the vehicle refrigerant heat insulating pipe 1 of Example 1, a skin layer 30 is formed on the surface of the heat insulating layer 3, that is, the surface of the vehicle refrigerant heat insulating pipe 1. The thickness of the skin layer 30 is slightly less than 1 mm.

[0136] In the thermal insulation pipe 1 for vehicle refrigerant of Example 1, a porous body having a porosity of about 50% is used as the heat insulation layer 3. Thus, the thermal insulation pipe 1 for vehicle refrigerant of Example 1 is provided with sufficient heat insulation performance.

[0137] In addition, regarding the insulated tube 1 for vehicle refrigerant of Example 1, a structure having a porosity of less than 20% and a Young's modulus of about 1350 MPa is used as the flow path forming layer 2. Therefore, regarding the insulated tube 1 for vehicle refrigerant of Example 1, the strength and rigidity of the flow path forming layer 2 are sufficiently improved. Moreover, as a result, regarding the insulated tube 1 for vehicle refrigerant of Example 1, its shape is stably maintained during bending and use. Furthermore, the connection strength of the insulated tube 1 for vehicle refrigerant of Example 1 to the supporting parts is also sufficiently improved.

[0138] Next, a method for manufacturing the thermally insulated tube 1 for vehicle refrigerant according to the first embodiment will be described.

[0139] The method for producing the thermal insulation pipe 1 for a vehicle refrigerant of the first embodiment includes an extrusion molding step based on an extrusion molding method called two-color extrusion molding or co-extrusion molding.

[0140] In the extrusion molding process, the flow path forming material serving as the material of the flow path forming layer 2 and the heat insulating material serving as the material of the heat insulating layer 3 are respectively introduced into a feeder of an extrusion molding machine (not shown), and a linear cylindrical body having the flow path forming layer 2 and the heat insulating layer 3 is extruded through a molding die of the extrusion molding machine.

[0141] The cylindrical body obtained by the above-mentioned extrusion molding step is heated and bent, thereby obtaining the thermal insulation pipe 1 for vehicle refrigerant of Example 1 which is bent into a substantially L-shape.

[0142] According to the manufacturing method of the vehicle refrigerant insulation tube 1 of Example 1, the flow path forming layer 2 and the insulation layer 3 are molded into one piece through an extrusion molding process, thereby obtaining the vehicle refrigerant insulation tube 1 of Example 1 which is different from the above-mentioned winding-bonding type vehicle refrigerant insulation tube and has a compact insulation layer 3 without waste.

[0143] In addition, according to the manufacturing method of the vehicle refrigerant insulated pipe 1 of Example 1, the flow path forming layer 2 and the heat insulating layer 3 are simultaneously molded by the extrusion molding process, thereby welding the flow path forming layer 2 and the heat insulating layer 3 to firmly join them. As a result, it is possible to suppress the peeling of the flow path forming layer 2 and the heat insulating layer 3 with high reliability, and it is possible to obtain the vehicle refrigerant insulated pipe 1 of Example 1 that is endowed with high strength and excellent durability.

[0144] Furthermore, the process of molding and welding the flow path forming layer 2 and the heat insulating layer 3 may be a single process such as an extrusion molding process. Thus, according to the manufacturing method of the vehicle refrigerant heat insulating tube 1 of the first embodiment, the vehicle refrigerant heat insulating tube 1 of the first embodiment can be easily manufactured.

[0145] (Example 2)

[0146] The thermally insulated tube for vehicle refrigerant of Example 2 is substantially the same as the thermally insulated tube for vehicle refrigerant of Example 1 except that it has a protective layer.

[0147] Therefore, the insulated tube for vehicle refrigerant of Example 2 is the insulated tube for vehicle refrigerant of the first aspect and the insulated tube for vehicle refrigerant of the second aspect. In addition, the manufacturing method of Example 2 is the manufacturing method of the third aspect and the manufacturing method of the fourth aspect. Therefore, in addition, it can be said that the insulated tube for vehicle refrigerant of Example 2 is also the insulated tube for vehicle refrigerant of the fifth aspect and the insulated tube for vehicle refrigerant of the sixth aspect.

[0148] exist Figure 4 , which schematically illustrates a radial cross section of a thermal insulation pipe for a vehicle according to Embodiment 2. Figure 5 Detailed Description of the Invention An explanatory diagram schematically illustrating an axial cross section of a thermal insulation tube for a vehicle according to Example 2 is shown.

[0149] Next, the thermally insulated tube for vehicle refrigerant of Example 1 and the method for manufacturing the same will be described, centering on the differences from the thermally insulated tube for vehicle refrigerant of Example 1. FIG.

[0150] like Figure 4 and Figure 5 As shown, the vehicle refrigerant insulated pipe 1 of the second embodiment has a protective layer 5 covering the entire surface of the heat insulating layer 3 from the radially outer side. The protective layer 5 is made of foam PA, and its porosity is about 10%. In addition, the thickness of the protective layer 5 is about 1 mm, which is about 0.6 to 0.7 times the thickness of the flow path forming layer 2.

[0151] The melting point of PA is higher than that of TPO. Therefore, in the thermal insulation pipe 1 for vehicle refrigerant of Example 2, the heat resistance of the protective layer 5 made of foamed PA is superior to that of the thermal insulation layer 3 made of foamed TPO.

[0152] According to the insulated refrigerant pipe 1 for a vehicle of the second embodiment, the outer side of the heat insulating layer 3 is covered with the protective layer 5, so that the insulated refrigerant pipe 1 for a vehicle can be provided with excellent heat resistance, thereby improving the durability of the insulated refrigerant pipe 1 for a vehicle.

[0153] The thermally insulated tube for vehicle refrigerant of Example 2 is similar to the thermally insulated tube for vehicle refrigerant 1 of Example 1, in which sufficient thermal insulation performance is imparted by the thermal insulation layer 3 .

[0154] In addition, the insulated tube 1 for vehicle refrigerant of Example 2 has a sufficiently improved strength and rigidity of the flow path forming layer 2, similarly to the insulated tube 1 for vehicle refrigerant of Example 1, and its shape is stably maintained during bending and use. Furthermore, the insulated tube 1 for vehicle refrigerant of Example 2 has a sufficiently improved connection strength to the supporting parts, similarly to the insulated tube 1 for vehicle refrigerant of Example 1.

[0155] The method for producing the thermally insulated tube 1 for a vehicle refrigerant of the second embodiment has the same extrusion molding step as the method for producing the thermally insulated tube 1 for a vehicle refrigerant of the first embodiment.

[0156] More specifically, regarding the manufacturing method of the thermal insulation pipe for vehicle refrigerant of Example 2, in the extrusion molding process, the flow path forming material serving as the material of the flow path forming layer 2, the thermal insulation material serving as the material of the thermal insulation layer 3, and the protective material serving as the material of the protective layer 5 are respectively introduced into the feeder of an extrusion molding machine (not shown), and a straight cylindrical body having the flow path forming layer 2, the thermal insulation layer 3 and the protective layer 5 is extruded through the molding die of the extrusion molding machine.

[0157] The cylindrical body obtained by the extrusion molding step is heated and bent, thereby obtaining the thermal insulation pipe 1 for vehicle refrigerant of Example 2 which is bent into a substantially L-shape.

[0158] According to the manufacturing method of the vehicle refrigerant insulation tube 1 of Example 2, the flow path forming layer 2, the insulation layer 3 and the protective layer 5 are molded into one piece through an extrusion molding process, so that the vehicle refrigerant insulation tube 1 of Example 2 which is different from the above-mentioned winding-bonding type vehicle refrigerant insulation tube and has compact insulation layer 3 and protective layer 5 without waste can be obtained.

[0159] In addition, according to the manufacturing method of the vehicle refrigerant insulated tube 1 of Example 2, the flow path forming layer 2, the thermal insulation layer 3 and the protective layer 5 are simultaneously molded through an extrusion molding process, thereby the flow path forming layer 2 and the thermal insulation layer 3 are welded to make them firmly joined, and the thermal insulation layer 3 and the protective layer 5 are welded to make them firmly joined.

[0160] Thus, according to the method for manufacturing the thermally insulated tube 1 for vehicle refrigerant of the second embodiment, it is possible to suppress the peeling of the flow path forming layer 2 and the heat insulating layer 3 with high reliability, and it is possible to suppress the peeling of the heat insulating layer 3 and the protective layer 5 with high reliability. And, as a result, it is possible to obtain the thermally insulated tube 1 for vehicle refrigerant of the second embodiment which is endowed with high strength and excellent durability.

[0161] Although the present invention has been described above, the present invention is not limited to the above-described embodiments and the like, and elements described in the embodiments and the like may be appropriately extracted and combined for implementation, and various modifications may be made within a scope not departing from the gist of the present invention.

[0162] In addition, the description of the present invention is not limited to the reference relationship of each claim at the time of filing, and discloses a technical idea obtained by appropriately combining the matters described in each claim.

[0163] Description of the label

[0164] 1: Insulated pipe for vehicle refrigerant; 2: Flow path forming layer; 3: Insulating layer; 4: Flow path; 5: Protective layer.

Claims

1. A thermally insulated pipe for vehicle refrigerant, comprising a flow path for vehicle refrigerant, wherein: The vehicle refrigerant heat insulation pipe comprises: a flow path forming layer which divides the flow path inside; and a heat insulation layer which covers the flow path forming layer from the radially outer side. The porosity of the flow path forming layer is less than 20%, and the porosity of the heat insulating layer is greater than or equal to 20% and less than 80%.

2. A thermally insulated pipe for vehicle refrigerant, comprising a flow path for vehicle refrigerant, wherein: The vehicle refrigerant heat insulation pipe comprises: a flow path forming layer which divides the flow path inside; and a heat insulation layer which covers the flow path forming layer from the radially outer side. The Young's modulus of the flow path forming layer is greater than or equal to 1000 MPa and less than or equal to 4000 MPa, and the Young's modulus of the heat insulating layer is less than 1000 MPa.

3. The thermal insulation pipe for vehicle refrigerant according to claim 1, wherein: The flow path forming layer has a Young's modulus of greater than or equal to 1000 MPa and less than or equal to 4000 MPa.

4. The thermal insulation pipe for vehicle refrigerant according to claim 2, wherein: The porosity of the heat insulation layer is greater than or equal to 20% and less than 80%.

5. The thermal insulation pipe for vehicle refrigerant according to claim 1, wherein: The vehicle refrigerant heat insulation pipe further includes a protective layer covering the heat insulation layer from the radially outer side. The porosity of the protective layer is less than 20%.

6. The thermal insulation pipe for vehicle refrigerant according to claim 2, wherein: The vehicle refrigerant heat insulation pipe further includes a protective layer covering the heat insulation layer from the radially outer side. The porosity of the protective layer is less than 20%.

7. A method for manufacturing a heat-insulated tube for vehicle refrigerant, the method being a method for manufacturing a tube having a flow path for vehicle refrigerant and comprising: a flow path forming layer which divides the flow path internally; and a heat-insulating layer which covers the flow path forming layer from the radially outer side, wherein: The manufacturing method of the insulated pipe for vehicle refrigerant has the following extrusion molding process, that is, using the flow path forming material as the material of the flow path forming layer and the thermal insulation material as the material of the thermal insulation layer, the flow path forming layer having a porosity less than 20% and the thermal insulation layer having a porosity greater than or equal to 20% and less than 80% are extruded.

8. A method for manufacturing a heat-insulated tube for vehicle refrigerant, the method being a method for manufacturing a tube having a flow path for vehicle refrigerant and comprising: a flow path forming layer which divides the flow path internally; and a heat-insulating layer which covers the flow path forming layer from the radially outer side, wherein: The manufacturing method of the insulated pipe for vehicle refrigerant has the following extrusion molding process, that is, using the flow path forming material as the material of the flow path forming layer and the insulation material as the material of the insulation layer, the flow path forming layer with a Young's modulus greater than or equal to 1000MPa and less than or equal to 4000MPa and the insulation layer with a Young's modulus less than 1000MPa are extruded.

9. A thermal insulation pipe for vehicle refrigerant, wherein: The thermal insulation pipe for vehicle refrigerant is obtained by extrusion molding using the manufacturing method according to claim 7.

10. A thermal insulation pipe for vehicle refrigerant, wherein: The thermal insulation pipe for vehicle refrigerant is obtained by extrusion molding using the manufacturing method according to claim 8.

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