Bass reflex port and speaker system equipped therewith

Abstract

This invention provides a bass reflex port that can effectively suppress port noise, and a speaker system equipped therewith. [Solution] The inner circumferential surface 50 of the bass reflex port 40 comprises a straight pipe section 51 having a constant diameter d0 along the axial direction, and an enlarged diameter section 52 whose diameter gradually increases as it moves away from the straight pipe section 51 along the axial direction. The enlarged diameter section 52 has a first enlarged diameter section 53 and a second enlarged diameter section 54. The axial length L1 of the first enlarged diameter section 53 is 15% or more of the diameter d0 of the straight pipe section 51, and the enlargement ratio d1 / d0 in the first enlarged diameter section 53 is 125% or less. An angle section 55 with a locally smaller radius of curvature is formed at the boundary between the first enlarged diameter section 53 and the second enlarged diameter section 54.

Description

Technical Field

[0006] , , , ,

[0001] The present disclosure relates to a bass reflex port and a speaker system including the same.

Background Art

[0002] As a speaker system, one including a bass reflex port for amplifying bass is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a speaker system including a bass reflex port, so-called port noise is likely to occur particularly when reproducing bass at a large input.

[0005] An object of the present disclosure is to provide a bass reflex port capable of effectively suppressing port noise and a speaker system including the same.

Means for Solving the Problems

[0006] A bass reflex port according to a first aspect is a bass reflex port, wherein an inner peripheral surface of the bass reflex port includes a straight pipe portion having a constant diameter d0 along an axial direction, and a diameter increasing portion in which a diameter gradually increases in a direction away from the straight pipe portion along the axial direction. The diameter increasing portion includes, in order from a side closer to the straight pipe portion, a first diameter increasing portion and a second diameter increasing portion. An axial length L1 of the first diameter increasing portion is 15% or more of a diameter d0 of the straight pipe portion, a diameter expansion ratio d1 / d0 in the first diameter increasing portion is 125% or less, and a corner portion having a locally small curvature radius is formed at a boundary between the first diameter increasing portion and the second diameter increasing portion.

[0007] In this embodiment, the inner circumferential surface of the bass reflex port comprises a straight pipe section having a constant diameter d0 along the axial direction, and an enlarged diameter section whose diameter gradually increases as it moves away from the straight pipe section along the axial direction. The enlarged diameter section comprises a first enlarged diameter section and a second enlarged diameter section, in order from the side closest to the straight pipe section.

[0008] In this embodiment, the axial length L1 of the first enlarged diameter section is 15% or more of the diameter d0 of the straight pipe section, and the enlargement ratio d1 / d0 in the first enlarged diameter section is 125% or less. In other words, the diameter expansion ratio in the first enlarged section, which has a certain length of 15% or more of the diameter d0 of the straight pipe section, is 125% or less. This means that the internal space of the bass reflex port expands gradually in the first enlarged section, which is the beginning of the enlarged section. As a result, the generation of vortices can be suppressed.

[0009] However, even with the above configuration, it is not possible to completely suppress the generation of vortices. Therefore, in this embodiment, a corner portion with a locally smaller radius of curvature is formed at the boundary between the first enlarged diameter portion and the second enlarged diameter portion. Therefore, the corner can eliminate any vortices that were about to form.

[0010] Based on the above, port noise can be effectively suppressed according to this embodiment.

[0011] In the embodiments described later, the first enlarged diameter portion has a uniform radius of curvature, and the second enlarged diameter portion has a uniform radius of curvature, but this embodiment is not limited thereto. The first enlarged diameter portion and the second enlarged diameter portion in this embodiment may each have a non-uniform radius of curvature that cannot be expressed by a constant radius of curvature. In the embodiments described later, the mean radius of curvature of the second enlarged diameter portion is smaller than the mean radius of curvature of the first enlarged diameter portion, but this embodiment is not limited to this. In the embodiment described later, the diameter of the straight pipe section is 65 mm, but this embodiment is not limited to this.

[0012] In the second embodiment of the bass reflex port, the axial length L2 of the enlarged diameter portion is 20% or more of the diameter d0 of the straight pipe portion, and the enlargement ratio d2 / d0 in the enlarged diameter portion is 150% or less.

[0013] By the way, if the diameter expansion ratio d2 / d0 in the expanded section is too large, vortices are more likely to be generated when air returns to the inside of the bass reflex port. Therefore, in this embodiment, the diameter expansion ratio d2 / d0 in the expanded portion is 150% or less. Therefore, it is possible to suppress the generation of vortices when air returns to the inside of the bass reflex port.

[0014] In the third embodiment of the bass reflex port, the axial length L2 of the enlarged diameter portion is 20% or more of the diameter d0 of the straight pipe portion, and the enlargement ratio d2 / d0 in the enlarged diameter portion is 130% or more.

[0015] By the way, if the diameter expansion ratio d2 / d0 in the expanded section is too small, vortices are more likely to be generated when air exits the bass reflex port. Therefore, in this embodiment, the diameter expansion ratio d2 / d0 in the expanded portion is 130% or more. Therefore, it is possible to suppress the generation of vortices when air exits the bass reflex port.

[0016] In the fourth embodiment, the bass reflex port, in the first embodiment, has an axial length L2 of the enlarged diameter portion that is 20% or more of the diameter d0 of the straight pipe portion, and an enlargement ratio d2 / d0 in the enlarged diameter portion that is 130% or more and 150% or less.

[0017] In this embodiment, the diameter expansion ratio d2 / d0 in the expanded portion is 130% or more and 150% or less. Therefore, it is possible to suppress the generation of vortices when air returns to the inside of the bass reflex port, as well as when air exits the bass reflex port to the outside.

[0018] In the fifth aspect, in any of the first to fourth aspects, the average radius of curvature of the first diameter-expanded portion is smaller than the average radius of curvature of the second diameter-expanded portion.

[0019] In this aspect, the average radius of curvature of the first diameter-expanded portion is smaller than the average radius of curvature of the second diameter-expanded portion. Therefore, compared with the aspect where the average radius of curvature of the first diameter-expanded portion is the same as or larger than the average radius of curvature of the second diameter-expanded portion, the generation of vortices when air exits from the bass reflex port to the outside can be effectively suppressed. This is because by reducing the radius of curvature of the second diameter-expanded portion, it is easier to increase the angle of the tangent line (the tangent line in the cross-section passing through the central axis of the bass reflex port) at the end of the second diameter-expanded portion with respect to the central axis.

[0020] In the sixth aspect, in the fifth aspect, the first diameter-expanded portion has a constant radius of curvature, and the second diameter-expanded portion has a constant radius of curvature.

[0021] In this aspect, the first diameter-expanded portion has a constant radius of curvature, and the second diameter-expanded portion has a constant radius of curvature. Therefore, compared with the aspect where the first diameter-expanded portion or the second diameter-expanded portion has a non-uniform radius of curvature, the design of the bass reflex port is easier.

[0022] In the seventh aspect, in any of the first to sixth aspects, the diameter-expanded portion has an axisymmetric shape.

[0023] In this aspect, the diameter-expanded portion has an axisymmetric shape. Therefore, compared with the aspect where the diameter-expanded portion has a non-axisymmetric shape, the manufacturing cost can be reduced.

[0024] The speaker system according to the eighth aspect includes a speaker unit, a speaker box, and a bass reflex port according to the first aspect.

[0025] According to this aspect, a speaker system capable of effectively suppressing port noise can be realized.

Brief Description of Drawings

[0026] [Figure 1] This figure shows a portion of the inner surface (a portion near the end) of the bass reflex port in this embodiment. [Figure 2] This is an enlarged view of Figure 1. [Figure 3] This is a cross-sectional view of the speaker system. [Figure 4] This is a cross-sectional view showing a modified example of the speaker system. [Modes for carrying out the invention]

[0027] Preferred embodiments of the bass reflex port and speaker system comprising the same as described herein will be described below.

[0028] (Bass reflex port 40) Figure 1 shows a part of the inner circumferential surface 50 of the bass reflex port 40 in this embodiment (a part near the end). Hereinafter, the direction parallel to the central axis AX of the bass reflex port 40 will be referred to as the axial direction, the direction perpendicular to the central axis AX will be referred to as the radial direction, and the direction around the central axis AX will be referred to as the circumferential direction.

[0029] The inner circumferential surface 50 of the bass reflex port 40 has an axisymmetric shape. The inner circumferential surface 50 of the bass reflex port 40 has a straight pipe section 51 having a constant diameter d0 along the axial direction, and an enlarged diameter section 52 whose diameter gradually increases as it moves away from the straight pipe section 51 along the axial direction.

[0030] The diameter d0 of the straight pipe section 51 is, for example, 55 mm to 75 mm. In this embodiment, as an example, the diameter d0 of the straight pipe section 51 is 65 mm.

[0031] The enlarged diameter section 52 has, in order from the side closest to the straight pipe section 51, a first enlarged diameter section 53 and a second enlarged diameter section 54.

[0032] The length L1 (axial dimension) of the first enlarged diameter section 53 is, for example, 15% to 20% of the diameter d0 of the straight pipe section 51. The diameter d0 at the starting end of the first enlarged diameter section 53 is the same as the diameter d0 of the straight pipe section 51, which is 65 mm. The diameter d1 at the end of the first enlarged diameter section 53 is, for example, 70 mm to 80 mm. In other words, the diameter enlargement ratio d1 / d0 of the first enlarged diameter section 53 is, for example, 107% to 123%, and more preferably 112% to 119%. The first enlarged diameter section 53 has a shape that is convex radially inward in a cross-section passing through the central axis AX (see Figure 1) and has a uniform radius of curvature. The radius of curvature of the first enlarged diameter section 53 is 700% to 850% of the diameter d0 of the straight pipe section 51, and in this embodiment, for example, it is 50 mm (approximately 770%).

[0033] The combined length (radial dimension) of the first enlarged diameter section 53 and the second enlarged diameter section 54, that is, the length L2 of the enlarged diameter section 52, is, for example, 20% to 34% of the diameter d0 of the straight pipe section 51. The diameter d1 at the starting end of the second enlarged diameter section 54 is the same as the diameter d1 at the ending end of the first enlarged diameter section 53. The diameter d2 at the end of the second enlarged section 54 is, for example, 90 mm to 102 mm. The end of the second enlarged section 54 is the end of the entire enlarged section 52. Therefore, the enlargement ratio d2 / d0 of the enlarged section 52 is, for example, 138% to 150%. The second enlarged diameter section 54 has a shape that is convex radially inward in a cross-section passing through the central axis AX (see Figure 1) and has a uniform radius of curvature. The radius of curvature of the second enlarged diameter section 54 is 550% to 700% of the diameter d0 of the straight pipe section 51, and in this embodiment, for example, it is 40 mm (approximately 615%).

[0034] At the boundary between the first enlarged diameter section 53 and the second enlarged diameter section 54, a corner section 55 is formed in which the radius of curvature is locally reduced. Specifically, as shown in Figure 2, in a cross-section passing through the central axis AX, the angle of the tangent T54A at the starting end of the second enlarged diameter section 54 with respect to the axial direction is greater than the angle of the tangent T53B at the end of the first enlarged diameter section 53 with respect to the axial direction. Therefore, a corner 55 that is convex radially inward is formed at the boundary between the first enlarged diameter section 53 and the second enlarged diameter section 54. At the corner 55, the radius of curvature is locally smaller compared to the first enlarged diameter section 53 and the second enlarged diameter section 54.

[0035] The enlarged diameter portion 52, in its entirety, including the first enlarged diameter portion 53, the corner portion 55, and the second enlarged diameter portion 54, does not have a shape that is radially convex outward in the cross-section passing through the central axis AX. Furthermore, the enlarged diameter portion 52, in its entirety, including the first enlarged diameter portion 53, the corner portion 55, and the second enlarged diameter portion 54, does not have a portion in which the cross-sectional area decreases as it moves outward along the axial direction from the bass reflex port 40.

[0036] (Speaker system 10) Next, we will describe the speaker system 10.

[0037] As shown in Figure 3, the speaker system 10 comprises a speaker unit 20 having a diaphragm, a magnetic circuit, etc., a speaker box 30, and a bass reflex port 40.

[0038] The speaker unit 20 and the bass reflex port 40 are provided on the front wall 31 side of the speaker box 30. In other words, in this embodiment, the front wall 31 is the wall through which the bass reflex port 40 opens.

[0039] The front wall 31 and the bass reflex port 40 are formed separately, and the bass reflex port 40 is attached to the front wall 31. However, the bass reflex port 40 may be integrally molded with the wall through which the bass reflex port 40 opens (the front wall 31 in the example shown). Alternatively, the bass reflex port 40 may be provided on a wall other than the front wall 31 (for example, the rear wall 32 side).

[0040] The bass reflex port 40 has an enlarged diameter portion 52 at the outer end of the speaker box 30. On the other hand, the bass reflex port 40 does not have an enlarged diameter portion 52 at the inner end of the speaker box 30.

[0041] (Variation 1) As shown in Figure 4(A), the enlarged diameter portion 52 may be provided not only at the outer end of the bass reflex port 40 that is connected to the speaker box 30, but also at the inner end of the speaker box 30. In this case, port noise can be suppressed even more effectively.

[0042] (Variations 2, 3) As shown in Figures 4(B) and 4(C), the bass reflex port 40 may have through-holes 60 for suppressing tube resonance. The through-holes 60 are provided corresponding to the straight tube section 51. It is also preferable that multiple through-holes 60 (for example, four) are provided at intervals in the circumferential direction.

[0043] As shown in Figures 4(B) and 4(C), the through-hole 60 is preferably located at the axial center of the bass reflex port 40 (at a position 1 / 2 × L0 from the outer end of the speaker box 30). Furthermore, as shown in Figure 4(C), the through-hole 60 is also preferably located at a position 3 / 4 × L0 from the outer end of the speaker unit of the bass reflex port 40. By positioning it at an antinode of the pressure amplitude of the tube resonance, the tube resonance can be effectively suppressed.

[0044] <Effects and Effects> Next, the effects and advantages of this embodiment will be described.

[0045] In this embodiment, as shown in Figure 1, the inner circumferential surface 50 of the bass reflex port 40 includes a straight pipe section 51 having a constant diameter d0 along the axial direction, and an enlarged diameter section 52 whose diameter gradually increases as it moves away from the straight pipe section 51 along the axial direction. The enlarged diameter section 52 has, in order from the side closest to the straight pipe section 51, a first enlarged diameter section 53 and a second enlarged diameter section 54.

[0046] In this embodiment, the axial length L1 of the first enlarged diameter section 53 is 15% or more of the diameter d0 of the straight pipe section 51, and the enlargement ratio d1 / d0 in the first enlarged diameter section 53 is 125% or less. In other words, the diameter expansion ratio in the first enlarged diameter section 53, which has a length of at least 15% of the diameter d0 of the straight pipe section 51, is 125% or less. This means that in the first enlarged diameter section 53, which is the beginning section of the enlarged diameter section 52, the internal space of the bass reflex port 40 expands gradually. As a result, the generation of vortices can be suppressed.

[0047] However, even with the above configuration, it is not possible to completely suppress the generation of vortices. Therefore, in this embodiment, a corner portion 55 with a locally smaller radius of curvature is formed at the boundary between the first enlarged diameter portion 53 and the second enlarged diameter portion 54. Therefore, the corner portion 55 can eliminate any vortices that were about to form.

[0048] Based on the above, this embodiment can effectively suppress port noise.

[0049] By the way, if the diameter expansion ratio d2 / d0 in the expanded diameter section 52 is too large, vortices are more likely to be generated when air returns to the inside of the bass reflex port 40. Therefore, in this embodiment, the diameter expansion ratio d2 / d0 in the expanded diameter portion 52 is 150% or less. Therefore, the generation of vortices when air returns to the inside of the bass reflex port 40 can be suppressed.

[0050] By the way, if the diameter expansion ratio d2 / d0 in the expanded diameter section 52 is too small, vortices are more likely to be generated when air exits the bass reflex port 40. Therefore, in this embodiment, the diameter expansion ratio d2 / d0 in the expanded diameter portion 52 is 130% or more. Therefore, the generation of vortices when air exits the bass reflex port 40 can be suppressed.

[0051] Furthermore, in this embodiment, the average radius of curvature of the first enlarged diameter portion 53 is smaller than the average radius of curvature of the second enlarged diameter portion 54. Therefore, compared to a configuration where the average radius of curvature of the first enlarged diameter section 53 is the same as or larger than the average radius of curvature of the second enlarged diameter section 54, the generation of vortices when air exits the bass reflex port 40 can be effectively suppressed. This is because reducing the radius of curvature of the second enlarged diameter section 54 makes it easier to increase the angle of the tangent T54B (the tangent in the cross-section passing through the central axis of the bass reflex port) at the end of the second enlarged diameter section 54 with respect to the central axis AX.

[0052] Furthermore, in this embodiment, the first enlarged diameter portion 53 has a constant radius of curvature, and the second enlarged diameter portion 54 has a constant radius of curvature. Therefore, the design of the bass reflex port 40 is easier compared to an embodiment in which the first enlarged diameter portion 53 or the second enlarged diameter portion 54 has an uneven radius of curvature.

[0053] Furthermore, in this embodiment, the enlarged diameter portion 52 has an axisymmetric shape. Therefore, compared to a configuration in which the enlarged diameter portion 52 has a non-axisymmetric shape, manufacturing costs can be reduced.

[0054] Furthermore, the speaker system 10 according to this embodiment includes a speaker unit 20, a speaker box 30, and a bass reflex port 40. According to this embodiment, a speaker system 10 that can effectively suppress port noise can be realized.

[0055] Furthermore, the angle of the tangent line T53A (see Figure 2) at the starting end of the first enlarged diameter portion 53 with respect to the central axis AX is preferably 5 to 17 degrees from the viewpoint of suppressing the generation of vortices.

[0056] Furthermore, the angle of the tangent T54B (see Figure 2) at the end of the second enlarged diameter portion 54 with respect to the central axis AX is preferably 60 to 70 degrees, from the viewpoint of suppressing vortices when air returns to the inside of the bass reflex port 40 and when air exits the bass reflex port 40 to the outside.

[0057] Furthermore, the angle between the tangent T54A at the starting end of the second enlarged diameter section 54 and the tangent T53B at the end of the first enlarged diameter section 53 is preferably 10 to 30 degrees.

[0058] While preferred embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above. [Explanation of symbols]

[0059] 10 Speaker System 20 speaker units 30 Speaker Box 31 Front wall 32 Back wall 40 Bass reflex ports 50 Inner surface 51 Straight pipe section 52 Expanded diameter part 53 First enlarged diameter part 53A Starting point 53B Termination 54 Second enlarged diameter section 54A Starting point 54B termination 55 corners 60 through holes AX center axis

Claims

1. It is a bass reflex port, The inner surface of the bass reflex port is A straight pipe section having a constant diameter d0 along the axial direction, The diameter of the enlarged section gradually increases as it moves away from the straight pipe section along the axial direction, Equipped with, The enlarged diameter portion is arranged in order from the side closest to the straight pipe portion: The first enlarged diameter section, The second enlarged diameter section, It has, The axial length L1 of the first enlarged diameter portion is 15% or more of the diameter d0 of the straight pipe portion. The diameter expansion ratio d1 / d0 in the first diameter expansion portion is 125% or less. At the boundary between the first enlarged diameter portion and the second enlarged diameter portion, a corner portion is formed in which the radius of curvature is locally reduced. Bass reflex port.

2. The axial length L2 of the enlarged diameter portion is 20% or more of the diameter d0 of the straight pipe portion. The diameter expansion ratio d2 / d0 in the aforementioned expanded portion is 150% or less. The bass reflex port according to claim 1.

3. The axial length L2 of the enlarged diameter portion is 20% or more of the diameter d0 of the straight pipe portion. The diameter expansion ratio d2 / d0 in the aforementioned expanded portion is 130% or more. The bass reflex port according to claim 1.

4. The axial length L2 of the enlarged diameter portion is 20% or more of the diameter d0 of the straight pipe portion. The diameter expansion ratio d2 / d0 in the aforementioned expanded portion is 130% or more and 150% or less. The bass reflex port according to claim 1.

5. The average radius of curvature of the first enlarged diameter portion is smaller than the average radius of curvature of the second enlarged diameter portion. The bass reflex port according to claim 1.

6. The first enlarged diameter portion has a certain radius of curvature, The second enlarged diameter portion has a certain radius of curvature. The bass reflex port according to claim 5.

7. The enlarged diameter portion has an axisymmetric shape. The bass reflex port according to claim 1.

8. Speaker unit and Speaker box and, The bass reflex port according to claim 1, Equipped with, Speaker system.

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