Duct structure

Abstract

Provided is a duct structure with which it is possible to suppress a reduction in exhaust speed and to reduce noise. The duct structure comprises a plurality of tubes disposed in a housing. The plurality of tubes include: a first tube having the shortest conduit length; and a second tube having the longest conduit length. The conduit length of the second tube is greater than one times and less than 3 / 2 times the conduit length of the first tube.

Description

[Technical Field]

[0001] The present invention relates to a duct structure. [Background technology]

[0002] Patent Document 1 below describes providing through holes in the peripheral wall of an intake duct of an internal combustion engine in order to reduce intake noise caused by pulsation of intake air passing through the inside of the duct. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-017806 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 reduces intake noise, but there is a possibility that gas may leak out of the intake duct through through-holes in the peripheral wall of the intake duct. If gas leaks from the peripheral wall of the intake duct, the exhaust speed from the outlet may decrease.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a duct structure that can reduce noise while suppressing a decrease in exhaust speed. [Means for solving the problem]

[0006] A duct structure according to one aspect of the present invention includes a plurality of pipe sections arranged inside a housing. The plurality of pipe sections include a first pipe section having the shortest pipe length and a second pipe section having the longest pipe length. The pipe length of the second pipe section is greater than 1 time and less than 3 / 2 times the pipe length of the first pipe section. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a duct structure that can reduce noise while suppressing a decrease in exhaust speed.

[0008] The objects and advantages of the invention will be realized and attained by means of the elements and combinations set forth in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing a state in which the sun visor according to the embodiment of the present invention is fixed to a joint structure. [Figure 3] FIG. 3 is a schematic view showing a state in which the sun visor according to the embodiment of the present invention is detached from the joint structure. [Figure 4] FIG. 4 is a schematic diagram showing an example of the configuration of a sun visor according to an embodiment of the present invention. [Figure 5] FIG. 5 is a five-view diagram showing an example of the configuration of a sun visor according to an embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing an example of the configuration of a sun visor according to an embodiment of the present invention. [Figure 7] FIG. 7 is a diagram schematically showing the relationship in length of pipe lines, including manufacturing variations, in a plurality of pipe sections according to an embodiment of the present invention. [Figure 8] FIG. 8 is a schematic diagram showing a first modified example of the sun visor according to the embodiment of the present invention. [Figure 9] FIG. 9 is a schematic diagram showing a second modified example of the sun visor according to the embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram showing a third modified example of the sun visor according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] (composition) Fig. 1 is a schematic diagram showing an example of the configuration of a vehicle 100 according to an embodiment of the present invention. As shown in Fig. 1, the vehicle 100 includes a roof trim 130 disposed between a cabin 110 and a roof panel 120, an air flow passage 135 provided between the roof trim 130 and the roof panel 120, an air intake port 140 provided on the intake side of the air flow passage 135 (e.g., on the rear side of the cabin 110), an air discharge port 150 provided on the exhaust side of the air flow passage 135 (e.g., on the front side of the cabin 110), a cold source 160 for cooling the air in the air flow passage 135, and an airflow generating device 165 for generating an air flow from the air intake port 140 to the air discharge port 150.

[0011] The vehicle 100 also includes a heat radiation portion 170 that becomes hot due to solar radiation SR and radiates heat rays, a sun visor 1 (an example of the "duct structure" of the present invention) attached to the roof trim 130, a joint structure 181 that detachably attaches the sun visor 1 to the roof trim 130, and a ball joint structure 182 that supports the sun visor 130 rotatably relative to the roof trim 130.

[0012] For example, the roof trim 130 is paired with the roof panel 120 and installed on the top of the cabin 110. The cold source 160 has a temperature lower than that of the cabin 110. The cold source 160 creates a cooling space in the air flow passage 135 between the roof panel 120 and the roof trim 130. In the embodiment of the present invention, the type of the cold source 160 is not particularly limited, but one example is a film or coating that has the property of cooling when exposed to light. Such a film or coating is provided on the roof panel 120.

[0013] The air intake 140 and the air discharge 150 connect the cold air space where the cold air CA is generated to the cabin 110. The airflow generating device 165 draws air from the cabin 110 into the cold air space through the air intake 140, and discharges the air cooled in the cold air space (i.e., the cold air CA) into the cabin 110 through the air discharge 150.

[0014] Fig. 2 is a schematic diagram showing a state in which the sun visor 1 according to the embodiment of the present invention is fixed to the joint structure 181. As shown in Fig. 2, when the sun visor 1 is fixed to the joint structure 181 (i.e., when the sun visor 1 is stored on the roof trim 130 side), the air vent 32 (see, for example, Fig. 6 described later) provided on one end of the sun visor 1 is adjacent to or connected to the air outlet 150.

[0015] As described above, the air discharged from the air outlet 150 is cool air CA cooled by the cold source 160. The cool air CA discharged from the air outlet 150 is introduced into the space 31 inside the sun visor 1 (see, for example, FIG. 6 described later) through the vent 32 of the sun visor 1. The cool air CA introduced into the space 31 is then discharged to the outside of the sun visor 1 through the multiple pipes 5. The cool air CA protruding from the other end of the sun visor flows, for example, along the windshield (not shown) and reaches the heat radiation portion 170. The heat radiation portion 170 is cooled by the cool air CA that has flowed therein. An example of the heat radiation portion 170 is a dashboard provided on the front side of the cabin 110.

[0016] 3 is a schematic diagram showing a state in which the sun visor 1 according to the embodiment of the present invention is detached from the joint structure 181. As shown in FIG. 3, when the sun visor 1 is detached from the joint structure 181, the sun visor 1 is rotatably supported by the ball joint structure 182.

[0017] An occupant (not shown) can use the sun visor 1 for shading by removing the sun visor 1 from the joint structure 181 and rotating the sun visor 1 around the ball joint structure 182. When the sun visor 1 is being used for shading, the vent 32 provided on one end of the sun visor 1 is spaced apart from the air outlet 150. The cool air CA discharged from the air outlet 150 flows along the surface of the sun visor 1. For example, the occupant can cool down by receiving the cool air CA flowing along the surface of the sun visor 1 on their body.

[0018] Next, the configuration of the sun visor 1 will be described. FIG. 4 is a schematic diagram showing a configuration example of the sun visor 1 according to the embodiment of the present invention. FIG. 5 is a five-view diagram showing a configuration example of the sun visor 1 according to the embodiment of the present invention. In FIG. 5, (a) is a diagram showing the main surface S1 of the sun visor 1, (b) is a diagram showing the upper side surface S2 of the sun visor 1, (c) is a diagram showing the lower side surface S3 of the sun visor 1, (d) is a diagram showing the left side surface S4 of the sun visor 1, and (e) is a diagram showing the right side surface S5 of the sun visor 1. FIG. 6 is a cross-sectional view showing a configuration example of the sun visor 1 according to the embodiment of the present invention. FIG. 6 shows a cross section of the sun visor 1 cut along a plane parallel to the main surface S1.

[0019] As shown in Figures 4 to 6, the sun visor 1 includes a sun visor main body 3 (the "housing" of the present invention) and a plurality of pipes 5 arranged inside the sun visor main body 3. With regard to the plurality of pipes 5, Figure 4 shows a case where the number of pipes 5 is four, and Figures 5 and 6 show a case where the number of pipes 5 is four, but these are merely examples. In the embodiment of the present invention, the number of pipes 5 arranged inside the sun visor main body 3 may be more than one, and may be four, five, six or more.

[0020] The sun visor body 3 has a space 31 provided inside the sun visor body 3 and a vent 32 connecting the space 31 from the outside of the sun visor body 3. For example, the vent 32 is provided on the upper side surface S2 of the sun visor body 3. The upper side surface S2 is the side of one end of the sun visor 1 described above. The multiple pipes 5 are arranged in the space 31.

[0021] Each of the multiple pipes 5 has one end 51 connected to the space 31, the other end 52 connected to the outside of the sun visor body 3, and a pipe line 53 connecting the one end 51 and the other end 52. In each of the multiple pipes 5, the one end 51 opens within the space. The other end 52 opens at an end face (e.g., the lower side surface S3) of the sun visor body 3. This allows each of the multiple pipes 5 to function as an air passage from the inside to the outside of the sun visor body 3. By using the pipes 5 as an air passage, the cross-sectional area of ​​the exhaust can be narrowed, making it easy to increase the exhaust speed. The space 31 is closed except for the air vent 32 connected to the space 31 and the air passages formed by the multiple pipes 5.

[0022] The other end 52 of each of the multiple pipe portions 5 is aligned with an end face (e.g., the lower side surface S3) of the sun visor body 3. The other end 52 does not protrude from the end face (e.g., the lower side surface S3) of the sun visor body 3. This makes it possible to suppress an increase in the volume of the sun visor 1.

[0023] Each of the plurality of pipes 5 has a linear shape from one end 51 to the other end 52. This makes it possible to suppress a decrease in the speed of air (for example, cool air CA) flowing inside the pipe 5.

[0024] The multiple pipe sections 5 have a first pipe section 5A having the shortest length L from one end 51 to the other end 52 (i.e., the length of the pipe line 53; hereinafter, pipe line length), and a second pipe section 5B having the longest pipe line length L. If the pipe line length of the first pipe section 5A is L1 and the pipe line length of the second pipe section 5B is L2, then the pipe line length L of the second pipe section 5B is greater than 1 time but less than 3 / 2 times the pipe line length of the first pipe section 5A (L1 < L2 < L1 × 3 / 2).

[0025] Changing the duct length L changes the air column resonance frequency caused by a standing wave with a wavelength of 1 / 2, dispersing the sound pressure peak at a specific frequency. If the duct length L2 of the second tubular section 5B is set to less than 3 / 2 times the duct length L1 of the first tubular section 5A, the overtones do not overlap with other air column resonances, and the sound pressure decreases.

[0026] The multiple pipe sections 5 further include a third pipe section 5C having a pipe line length L longer than that of the first pipe section 5A and shorter than that of the second pipe section 5B. Multiple pipe sections 5 including the first pipe section 5A, the second pipe section 5B, and the third pipe section 5C are arranged in the space section 31. The pipe line lengths L of the multiple pipe sections 5 are not uniform, and are, for example, different lengths from one another.

[0027] The plurality of pipe sections 5 are arranged in parallel in one direction along an end face (for example, the lower side surface S3) of the sun visor body 3. The plurality of pipe sections 5 are arranged in line in one direction in the order of their pipe lengths L.

[0028] The inner diameters R of the plurality of pipe sections 5 (that is, the diameters of the pipe lines 53) are the same. In each of the plurality of pipe sections 5, the inner diameter R is constant from one end 51 to the other end 52.

[0029] The differences in the pipe lengths L of the multiple pipe sections 5 are not caused by manufacturing variations but are intentionally created by design. Fig. 7 is a diagram schematically showing the relationship in magnitude of the pipe lengths L, including manufacturing variations, of the multiple pipe sections 5 according to the embodiment of the present invention.

[0030] As shown in FIG. 7, the pipe length of the first pipe section 5A is L1, and the standard deviation of L1 is σL1. Similarly, the pipe length of the second pipe section 5B is L2, and the standard deviation of L2 is σL2. The average value of the pipe lengths L of the multiple pipe sections 5 is La. In an embodiment of the present invention, the pipe lengths L of the multiple pipe sections 5 are designed to be different from each other. The pipe lengths L of the multiple pipe sections 5 are intentionally changed in the design, rather than simply due to manufacturing variations, to shift the frequencies of the air column resonance sounds. As a result, as shown in FIG. 7, the average value La of the pipe lengths L of the multiple pipe sections 5 is greater than (L1 + 3 × σL1) and less than (3 / 2 × L1 - 3 × σL2).

[0031] The standard deviation σL1 can be calculated, for example, by preparing a plurality of sun visors 1 and actually measuring the pipe length L1 of the first pipe section 5A arranged in each of the prepared plurality of sun visors 1. Similarly, the standard deviation σL2 can be calculated, for example, by preparing a plurality of sun visors 1 and actually measuring the pipe length L2 of the second pipe section 5B arranged in each of the prepared plurality of sun visors 1.

[0032] (Manufacturing method) In the embodiment of the present invention, the method for manufacturing the sun visor 1 is not particularly limited. For example, the sun visor body 3 may be manufactured by combining multiple resin parts formed by integral molding. The pipe portion 5 may be formed by integral molding together with the parts that constitute the sun visor body 3, or the pipe portion 5 may be formed separately from the sun visor body 3 and then attached to the inside of the sun visor body 3.

[0033] (verification) An example of the present invention and a comparative example were prepared to verify the noise reduction effect. (1) Example As an example of the present invention, sun visors of the following sizes were prepared, and air was fed into one end of the sun visor through the vent hole, and the noise generated at the other end of the sun visor from which the air was discharged was measured. Cross-sectional dimensions of the opening of the pipe 5: 4.5 mm x 4.5 mm (R = 4.5 mm) - Thickness of sun visor body 3: 5mm Pipe length L of multiple pipe sections 5: 170 mm ± 48 mm (uneven) -Air flow rate into sun visor 1: 80m 3 / h(20m / s) (2) Comparative Example The length of the pipes in the multiple pipe sections was all 170 mm (uniform). All other conditions were the same as in the example. For the comparative example, air was sent in from one end of the sun visor through the vent, and the sound was measured at the other end of the sun visor where the air was discharged. (3) Verification results The example confirmed a noise reduction effect of -2 dB compared to the comparative example.

[0034] (Effects of the embodiment) As described above, the sun visor 1 according to the embodiment of the present invention includes a sun visor body 3 and a plurality of pipes 5 arranged inside the sun visor body 3. The sun visor body 3 has a space 31 provided inside the sun visor body 3 and a vent 32 connecting the space 31 from the outside of the sun visor body 3. Each of the plurality of pipes 5 has one end 51 connected to the space 31 and the other end 52 connected to the outside of the sun visor body 3. The plurality of pipes 5 includes a first pipe 5A having the shortest pipe length L from the one end 51 to the other end 52, and a second pipe 5B having the longest pipe length L. The pipe length L2 of the second pipe 5B is greater than 1 time and less than 3 / 2 times the pipe length L1 of the first pipe 5A.

[0035] According to this, the frequency of air column resonance generated by air (e.g., cold air CA) flowing through each of the multiple pipe sections 5 is different for each pipe section 5, and amplification of air column resonance sound of a specific frequency is suppressed. Since the specific frequency corresponding to the pipe length L is no longer the same among the multiple pipe sections 5, the noise level perceived by the human ear is reduced. Furthermore, since there is no need to provide through holes in the peripheral wall of the pipe section 5, a decrease in exhaust speed can be suppressed. This makes it possible to reduce noise while suppressing a decrease in exhaust speed.

[0036] The pipe length L2 of the second pipe section 5B is not limited to being less than 3 / 2 times the pipe length L1 of the first pipe section 5A, and may be 3 / 2 or more times the pipe length. In this case, the pipe lengths of the multiple pipe sections 5 are not uniform, and may be, for example, different lengths from one another. Of the multiple pipe sections 5, the pipe length L of the pipe sections 5 other than the first pipe section 5A is a value other than n / 2 times the pipe length L1 of the first pipe section 5A (n is an integer). In other words, the pipe length L of the pipe sections 5 other than the first pipe section 5A is not n / 2 times the pipe length L1 of the first pipe section 5A.

[0037] Even with this configuration, the frequency of air column resonance generated by air (e.g., cold air CA) flowing through each of the multiple pipe sections 5 is different for each pipe section 5, and amplification of air column resonance sound of a specific frequency is suppressed. Also, there is no need to provide through holes in the peripheral wall of the pipe section 5. This makes it possible to reduce noise while suppressing a decrease in exhaust speed.

[0038] (Variation 1) In the above embodiment, as shown in FIG. 4, for example, the multiple pipe sections 5 are arranged in one direction in the order of their pipe length L. However, the present invention is not limited to this. FIG. 8 is a schematic diagram showing a first modified example of a sun visor 1 according to an embodiment of the present invention. As shown in FIG. 8, the multiple pipe sections 5 may be arranged randomly in one direction regardless of the length of the pipe length L. Even with this configuration, the air column resonance frequencies of the individual pipe sections 5 are different from each other, and the amplification of air column resonance sounds of specific frequencies is suppressed. Therefore, similar to the above embodiment, it is possible to reduce noise while suppressing a decrease in exhaust speed.

[0039] (Variation 2) In the above embodiment, it has been described that the inner diameters R of the plurality of pipe sections 5 are the same. However, the embodiment of the present invention is not limited to this. Fig. 9 is a schematic diagram showing a modified example 2 of the sun visor 1 according to the embodiment of the present invention. As shown in Fig. 9, the inner diameters R of the plurality of pipe sections 5 do not have to be the same. For example, if the inner diameter of the first pipe section 5A is R1 and the inner diameter of the second pipe section 5B is R2, then R1 <R2であってもよい。

[0040] The longer the conduit length L, the greater the airflow resistance (i.e., the more difficult it is for air to flow). Also, the greater the inner diameter R of the conduit section 5, the smaller the airflow resistance tends to be. Therefore, the inner diameter R may be adjusted according to the conduit length L so that the inner diameter R becomes smaller as the conduit length L becomes longer. This makes it possible to make the airflow resistance more uniform among multiple conduit sections 5.

[0041] (Variation 3) In the embodiment of the present invention, the other ends 52 of the pipes 5 may be open not only on the lower side surface S3 of the sun visor body 3 but also on the left side surface S4 or the right side surface S5. Fig. 10 is a schematic diagram showing a third modification of the sun visor 1 according to the embodiment of the present invention. As shown in Fig. 10, the sun visor 1 may include a plurality of pipes 5 (first pipe group G1) whose other ends 52 open on the lower side surface S3 of the sun visor body 3, a plurality of pipes 5 (second pipe group G2) whose other ends 52 open on the left side surface S4 of the sun visor body 3, and a plurality of pipes 5 (third pipe group G3) whose other ends 52 open on the right side surface S5 of the sun visor body 3. The second pipe group G2 and the third pipe group G3 preferably have the same configuration as the first pipe group G1.

[0042] For example, the second pipe group G2 has a first pipe 5A having the shortest pipe length L and a second pipe 5B having the longest pipe length L. In the second pipe group G2, the pipe length L2 of the second pipe 5B is greater than 1 time and less than 3 / 2 times the pipe length L1 of the first pipe 5A.

[0043] Similarly, the third pipe group G3 has a first pipe 5A having the shortest pipe length L and a second pipe 5B having the longest pipe length L. In the third pipe group G3, the pipe length L2 of the second pipe 5B is greater than 1 time but less than 3 / 2 times the pipe length L1 of the first pipe 5A.

[0044] With this configuration, cool air CA can be discharged not only from the lower side surface S3 of the sun visor body 3 but also from the left side surface S4 and the right side surface S5. The air column resonance frequencies differ among the pipe sections 5 not only from the lower side surface S3 but also from the left side surface S4 and the right side surface S5, suppressing the amplification of air column resonance noise of specific frequencies. Therefore, similar to the above embodiment, it is possible to reduce noise while suppressing a decrease in exhaust speed. Furthermore, since cool air CA can be supplied in multiple directions, there is a possibility that the cooling effect can be improved.

[0045] (Application example) In the above embodiment, the "duct structure" of the present invention has been described as being applied to a sun visor mounted on a vehicle. However, the application of the "duct structure" of the present invention is not limited to this. The "duct structure" of the present invention may also be applied to a sun visor attached to something other than a vehicle, or to an article other than a sun visor. The "duct structure" of the present invention may also be applied to any article that includes a housing and a plurality of pipe portions arranged inside the housing and that discharges air from the plurality of pipe portions.

[0046] All examples and conditional terms described herein are intended for educational purposes to aid the reader in understanding the present invention and the concepts provided by the inventor for the advancement of technology, and should be construed without limitation to the specifically described examples and conditions above, and the configuration of examples herein for illustrating the advantages and disadvantages of the present invention. Although the embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0047] 1...sun visor, 3...sun visor body, 5...pipe section, 5A...first pipe section, 5B...second pipe section, 5C...third pipe section, 31...space section, 32...vent, 51...one end, 52...other end, 53...pipe line, 100...vehicle, 110...cabin, 120...roof panel, 130...roof trim, 135...air flow passage, 140...air intake port, 150...air discharge port, 160...cold source, 165...airflow generating device, 170...heat radiation section, 181...joint structure, 182...ball joint structure, CA...cold air, G1...first pipe section group, G2...second pipe section group, G3...third pipe section group, S1...main surface, S2...upper side surface, S3...lower side surface, S4...left side surface, S5...right side surface, SR...solar radiation

Claims

1. The housing and a plurality of pipes disposed inside the housing; The housing includes: a space provided inside the housing; a vent hole that connects the housing to the space portion from the outside, Each of the plurality of pipe portions is One end connected to the space; and the other end connected to the exterior of the housing, The plurality of pipe portions are a first pipe section having a shortest pipe length from the one end to the other end; a second pipe section having the longest pipe length; A duct structure, wherein the duct length of the second pipe section is greater than 1 time and less than 3 / 2 times the duct length of the first pipe section.

2. The duct structure according to claim 1 , wherein the space is closed except for the vent opening connected to the space and an air passage formed by the plurality of pipes.

3. The duct structure according to claim 1 or 2, wherein the other end of each of the plurality of pipe sections is aligned with an end face of the housing.

4. The duct structure according to claim 3 , wherein the plurality of pipe sections are arranged in parallel in one direction.

5. The length of the first pipe section is L1, and the standard deviation of L1 is σL1. When the pipe length of the second pipe section is L2 and the standard deviation of L2 is σL2, The duct structure according to claim 1 or 2, wherein an average value of the pipe lengths of the plurality of pipe sections is greater than (L1+3×σL1) and less than (3 / 2×L1−3×σL2).

6. The duct structure according to claim 1 or 2, wherein each of the plurality of pipe sections has a linear shape from the one end to the other end.

7. The inner diameter of the first pipe portion is R1, The duct structure according to claim 1 or 2, wherein R1<R2, where R2 is an inner diameter of the second pipe portion.

8. 3. The duct structure according to claim 1, wherein air is introduced into the space through the vent of the housing, and the air introduced into the space is discharged to the outside of the housing through the plurality of pipes.

9. The duct structure according to claim 1 or 2, wherein the air introduced into the space through the vent of the housing is cold air cooled by a cold source.

10. The housing and a plurality of pipes disposed inside the housing; The housing includes: a space provided inside the housing; a vent hole that connects the housing to the space portion from the outside, Each of the plurality of pipe portions is One end connected to the space; and the other end connected to the exterior of the housing, The pipe lengths from the one end to the other end are different among the plurality of pipe sections, The plurality of pipe portions are a first pipe section having the shortest pipe length; A duct structure, wherein the pipe length of the other pipe sections, excluding the first pipe section, among the plurality of pipe sections, is a value other than n / 2 times (n is an integer) the pipe length of the first pipe section.

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