Testing tool

Abstract

The utility model discloses a testing tool which comprises a tool body and a sealing ring, the tool body is provided with an annular groove with an upward opening, and the cross section of the annular groove in the direction perpendicular to the height direction of the tool body is gradually reduced upwards in the height direction; wherein the sealing ring is arranged on the annular groove. According to the utility model, the sealing ring is arranged in the annular groove of the dovetail groove structure, so that the situation that the sealing ring is taken up and falls off when multiple times of true water tests are carried out to cause sealing failure can be avoided, and the acoustic performance test is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of testing equipment, in particular to a testing tool. Background Art

[0002] During the research and development and production stages of micro speakers, it is usually necessary to test the air tightness, acoustic performance, listening effect and various performances of the speakers. The application scenarios of micro speakers are different, and the way of testing will also change accordingly. For example, in smart watches, with the continuous advancement of chip technology, battery technology and sensor technology, smart watches can achieve more functions, such as health monitoring, communication, navigation, etc., thereby increasing their practicality and attractiveness. At the same time, smart watches also have a waterproof rating of more than 5ATM, and the micro speakers in smart watches must also have a waterproof rating of more than 5ATM. Therefore, when testing micro speakers, real water testing can be used, but when testing micro speakers in real water testing, the sealing of the back cavity is particularly important. After multiple tests of the existing sealing structure, the sealing ring in the sealing structure is easy to fall off, resulting in sealing failure, affecting the effect of the acoustic performance test. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a test fixture to solve the problem that the sealing ring of the sealing structure on the existing test fixture is easy to fall off after multiple real water tests, resulting in sealing failure and affecting the acoustic performance test effect.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] A test tool, characterized in that it includes: a tool body and a sealing ring, wherein the tool body is provided with an annular groove opening upward, and the cross-section of the annular groove perpendicular to the height direction of the tool body gradually decreases upward along the height direction; wherein the sealing ring is arranged on the annular groove.

[0006] Furthermore, in the test fixture described in the utility model, the annular groove includes two arc grooves and two parallel linear grooves, the two arc grooves are respectively arranged at both ends of the linear groove, and the two ends of the arc groove are respectively connected to the two linear grooves.

[0007] Furthermore, in the testing tool described in the utility model, the sealing ring is made of silicone.

[0008] Furthermore, in the test fixture described in the utility model, a test groove opening upward is further provided on the fixture body, and the test groove is arranged in the annular area surrounded by the annular groove.

[0009] Furthermore, in the test tooling described in the present invention, the depth of the test groove gradually increases along the first direction, and a first opening and a second opening are provided in the test groove, and the first opening is arranged at a position in the test groove that is higher than the depth of the second opening; a first channel and a second channel that are connected to the outside are provided in the tooling body, and the first channel is connected to the first opening, and the second channel is connected to the second opening.

[0010] Furthermore, in the testing tool described in the utility model, the first channel and the second channel are respectively arranged on both sides of the testing groove.

[0011] Furthermore, in the test fixture described in the present utility model, the first channel includes a first sub-channel and a second sub-channel that are interconnected, and an extension direction of the first sub-channel is arranged at an angle to an extension direction of the second sub-channel.

[0012] Furthermore, in the test tool described in the present invention, the first end opening of the first sub-channel is communicated with the first opening, and the second end opening of the first sub-channel is arranged on a side surface of the tool body.

[0013] Furthermore, in the test tooling described in the present invention, one end of the second sub-channel is connected to the first sub-channel, and the other end is provided with a first opening section and a second opening section, the opening of the first opening section is arranged on the bottom surface of the tooling body, and the opening of the second opening section is arranged on a side surface of the tooling body.

[0014] Furthermore, in the test tooling described in the utility model, a first shielding portion and a second shielding portion are also provided on the tooling body, the first shielding portion is embedded in the second end opening of the first sub-channel, and the second shielding portion is embedded in the opening of the second opening section.

[0015] The beneficial effect of the utility model is that the utility model provides a test fixture, which includes a fixture body and a sealing ring. An annular groove with an opening upward is provided on the fixture body, and the cross section of the annular groove in the direction perpendicular to the height of the fixture body gradually decreases upward along the height direction, that is, the structure of the axial cross section of the annular groove is a dovetail groove structure that is small at the top and large at the bottom. When it is necessary to test with the test fixture, the sealing ring is set in the annular groove. Since the structure of the axial cross section of the annular groove is no longer a traditional straight groove structure, but a dovetail groove structure that is small at the top and large at the bottom, therefore, setting the sealing ring in the annular groove of the dovetail groove structure can avoid the sealing ring being lifted and falling off during multiple real water tests, thereby causing sealing failure, which is helpful for acoustic performance testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the test tool described in the utility model in one embodiment from one viewing angle;

[0017] Figure 2 A cross-sectional view of the cavity housing of the utility model in one embodiment at one viewing angle;

[0018] Figure 3 It is a schematic structural diagram of the cavity housing of the utility model in another viewing angle under one embodiment;

[0019] Figure 4 It is a schematic structural diagram of the sealing structure described in the utility model under another viewing angle in one implementation manner.

[0020] Description of labels:

[0021] 1. Tool body; 11. First through hole; 12. Second through hole;

[0022] 2. Sealing ring;

[0023] 3. Annular groove;

[0024] 4. test groove; 41. first opening; 42. second opening;

[0025] 51, first sub-channel; 52, second sub-channel; 521, first opening section; 522, second opening section;

[0026] 61, third sub-channel; 62, fourth sub-channel; 621, third opening section; 622, fourth opening section;

[0027] 71, first shielding portion; 72, second shielding portion; 73, third shielding portion; 74, fourth shielding portion;

[0028] 8. Micro speakers. DETAILED DESCRIPTION

[0029] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0030] Please refer to Figures 1 to 4 The utility model designs a test tool, which includes: a tool body 1 and a sealing ring 2, wherein the tool body 1 is provided with an annular groove 3 opening upward, and the cross section of the annular groove 3 perpendicular to the height direction of the tool body 1 gradually decreases upward along the height direction; wherein the sealing ring 2 is arranged on the annular groove 3.

[0031] From the above description, it can be seen that the beneficial effect of the utility model is that the utility model designs a test fixture, which includes a fixture body 1 and a sealing ring 2. An annular groove 3 with an opening upward is provided on the fixture body 1, and the cross section of the annular groove 3 in the height direction perpendicular to the fixture body 1 gradually decreases upward along the height direction, that is, the structure of the axial cross section of the annular groove 3 is a dovetail groove structure that is small at the top and large at the bottom. When it is necessary to test with the test fixture, the sealing ring 2 is set in the annular groove 3. Since the structure of the axial cross section of the annular groove 3 is no longer a traditional straight groove structure, but a dovetail groove structure that is small at the top and large at the bottom, therefore, the sealing ring 2 is set in the annular groove 3 of the dovetail groove structure, which can avoid the sealing ring 2 being lifted and fallen off during multiple real water tests, thereby causing the sealing failure, which is helpful for acoustic performance testing. It should be noted that when using the test fixture, a cover plate (not shown) will also be used in conjunction with the fixture body 1 for sealing to perform testing. At this time, the sealing ring 2 is partially embedded in the fixture body 1 and partially embedded in the cover plate. Specifically: when the cover plate is pressed down to the upper surface of the fixture body, the sealing ring 2 forms a seal with the fixture body 1, and the sealing ring 2 is deformed to fill the remaining dovetail groove (i.e., the annular groove 3) bottom space. When the cover plate is raised, since the sealing ring 2 is deformed and does not return to its original shape, the annular groove 3 is a shape that is small at the top and large at the bottom, resulting in the shape of the sealing ring being small at the top and large at the bottom. The sealing ring 2 is stuck in the annular groove 3 and is not easy to fall off, thereby preventing the sealing ring 2 from being lifted up and falling off by the cover plate.

[0032] Furthermore, in the test fixture described in the present invention, the annular groove 3 includes two arc grooves and two parallel linear grooves, the two arc grooves are respectively arranged at both ends of the linear groove, and the two ends of the arc groove are respectively connected to the two linear grooves.

[0033] In the above technical solution of the utility model, the annular groove 3 may include two arc grooves and two parallel straight grooves. Through the above two arc grooves and two straight grooves, the overall shape of the annular groove 3 can be an annular runway. Since the runway-shaped annular groove has a specific profile and depth, the silicone ring can be tightly embedded therein after installation to form a stable connection, which can reduce the risk of the silicone ring falling off during the test and ensure the reliability of the acoustic performance test of the micro speaker.

[0034] Furthermore, in the test tool described in the present invention, the sealing ring 2 is made of silicone.

[0035] In the above technical solution of the utility model, the material of the sealing ring 2 is silicone (i.e., a silicone ring), so that the sealing ring 2 has good sealing performance and can effectively prevent the entry of liquids, etc. In addition, the silicone ring has good elasticity and recovery, and can quickly return to its original shape after being subjected to pressure or deformation, so that it can fit tightly to the interface of the micro speaker to ensure a leak-free sealing effect.

[0036] Furthermore, in the test fixture described in the utility model, a test groove 4 opening upward is further provided on the fixture body 1, and the test groove is arranged in the annular area surrounded by the annular groove.

[0037] In the above technical solution of the utility model, in order to be able to perform a real water test on the micro speaker through the test tool, a test groove 4 can be set on the tool body 1. By setting the micro speaker in the test groove 4, the acoustic performance of the micro speaker can be effectively tested.

[0038] Furthermore, in the test tooling described in the present invention, the depth of the test groove gradually increases along the first direction, and a first opening 41 and a second opening 42 are provided in the test groove, and the position of the first opening 41 arranged in the test groove is higher than the depth of the second opening 42; a first channel and a second channel connected to the outside are provided in the tooling body, and the first channel is connected to the first opening 41, and the second channel is connected to the second opening 42.

[0039] In the above technical solution of the utility model, the groove depth of the test groove gradually increases along the first direction, that is, the groove bottom of the test groove 4 is an inclined surface, and the test groove is provided with a first opening (an opening for water injection and gas injection) and a second opening (an opening for drainage and exhaust), and the first opening is arranged in the test groove at a position higher than the groove depth of the second opening. On this basis, the first channel and the second channel leading to the external space are provided on the tool body, and the first channel is connected to the first opening, and the second channel is connected to the second opening. Since the bottom of the test groove is an inclined surface, the water flow can quickly flow out through the opening for drainage and exhaust at the bottom of the groove, that is, through the second opening, by using the principle that water flows to a lower place, so as to facilitate rapid and effective drainage after the test. It can be seen that in the real water test of the micro-speaker by the above-mentioned test tool, the performance changes of the micro-speaker after diving can be simulated, which is helpful for the debugging and control of acoustic performance. In addition, after the test is completed, the test tool of the utility model can also quickly drain water from the inclined surface of the bottom of the groove to improve the test efficiency.

[0040] When testing the acoustic performance of a micro-speaker by the test fixture of the utility model, the micro-speaker can be first placed on the test groove 4 of the test fixture, and then water can be injected to cover the surface of the micro-speaker, and then the test can be continued by inflating. Specifically: water can be injected through the external interface of the first channel, and the water flows in the first channel, and is injected into the test groove 4 through the first channel and the first opening connected thereto. Then, air is inflated through the first channel and the first opening connected thereto to conduct an acoustic performance test. After the test is completed, the water is drained and exhausted through the second opening and the second channel. Since the bottom of the test groove 4 is an inclined surface, the water can quickly flow out through the second opening by utilizing the principle that water flows to lower places, so that the water can be quickly and effectively drained after the test. In the real water test of the micro-speaker by the above-mentioned test fixture, the performance changes of the micro-speaker after diving can be simulated, which is helpful for the debugging and control of the acoustic performance.

[0041] Furthermore, in the testing tool described in the utility model, the first channel and the second channel are respectively arranged on both sides of the testing groove 4 .

[0042] In the above technical solution of the utility model, the first channel and the second channel are arranged on both sides of the test groove 4, so that water and air can be injected through the first channel on one side of the test groove 4, and drainage and exhaust can be carried out through the second channel on the other side of the test groove 4, thereby reducing the interference caused by being arranged on one side and facilitating maintenance. If it is arranged on one side, the first channel and the second channel may cross or be too close, affecting the use effect.

[0043] Furthermore, in the test fixture described in the present invention, the first channel includes a first sub-channel 51 and a second sub-channel 52 that are interconnected, and an extension direction of the first sub-channel 51 and an extension direction of the second sub-channel 52 are arranged at an angle.

[0044] In the above technical solution of the utility model, in order to save space, the first channel may include a first sub-channel 51 and a second sub-channel 52 that are interconnected, and the extension direction of the first sub-channel 51 is different from the extension direction of the second sub-channel 52. That is, the first channel has two sub-channels in different directions, and corresponding water injection and gas injection operations can be performed through the sub-channels in different extension directions.

[0045] Furthermore, in the test tool described in the present invention, the first end opening of the first sub-channel 51 is communicated with the first opening 41 , and the second end opening of the first sub-channel 51 is arranged on a side surface of the tool body 1 .

[0046] In the above technical solution of the utility model, one end of the first sub-channel is connected to the first opening, and the other end opening is arranged on a side surface of the tooling body, so that the first sub-channel can be connected to the test groove for corresponding water injection and gas injection operations.

[0047] Furthermore, in the test tooling described in the present invention, one end of the second sub-channel 52 is connected to the first sub-channel 51, and the other end is provided with a first opening section 521 and a second opening section 522, the opening of the first opening section 521 is arranged on the bottom surface of the tooling body 1, and the opening of the second opening section 522 is arranged on a side surface of the tooling body 1.

[0048] In the above technical solution of the present invention, one end of the second sub-channel 52 is connected to the first sub-channel 51, and two opening sections are correspondingly arranged at the other end, so that the test groove 4 can be injected with water and air through the first channel formed by the two opening sections, the second sub-channel 52 and the first sub-channel 51.

[0049] Furthermore, in the test tooling described in the present invention, a first shielding portion 71 and a second shielding portion 72 are also provided on the tooling body 1, the first shielding portion 71 is embedded in the second end opening of the first sub-channel 51, and the second shielding portion 72 is embedded in the opening of the second opening section 522.

[0050] In the above technical solution of the utility model, considering the processing problem, the right-angle channel cannot be directly dug out on the tooling body 1. The utility model sets a first shielding portion 71 and a second shielding portion 72 on the tooling body 1. The first shielding portion 71 is embedded in the second end opening of the first sub-channel 51, and the second shielding portion 72 is embedded in the opening of the second opening section 522.

[0051] Please refer to Figures 1 to 4 The first embodiment of the utility model is: a test tool, which includes a tool body 1 and a sealing ring 2, and the tool body 1 is roughly in the shape of a rectangular parallelepiped. Figure 3 As shown, the fixture body 1 is provided with an annular groove 3 extending along the length direction of the fixture body 1, and the annular groove 3 is a sealing groove. When the micro speaker is tested in real water by the test fixture, the sealing ring 2 can be set on the annular groove 3 to achieve a sealing state. In this embodiment, the annular groove 3 is set on the upper top surface of the fixture body 1 in the form of an opening upward, and the cross section of the annular groove 3 in the vertical height direction of the fixture body 1 gradually decreases upward along the height direction, as shown in FIG. Figure 2As shown, the test tooling is cut open along the height direction of the tooling body 1, and it can be seen that the cross section of the annular groove 3 is similar to a trapezoid. In addition, in this embodiment, observed from the top surface of the tooling body 1, the shape of the annular groove 3 can be an annular runway shape, specifically: the annular groove 3 includes two arc grooves and two parallel straight grooves, the two arc grooves are symmetrically arranged at a certain distance in the width direction of the tooling body 1, and the two straight grooves are arranged in parallel at a certain distance in the width direction of the tooling body 1, and the two straight grooves extend along the length direction of the tooling body 1. Among them, the two arc grooves are respectively arranged at the two ends of the straight groove, and the two ends of the arc groove are respectively connected to the straight groove, and the two arc grooves and the two straight grooves are enclosed to form a groove similar to the shape of a runway. It should be noted that the shape of the sealing ring 2 is also a runway shape similar to the annular groove 3, and the material of the sealing ring 2 is silicone.

[0052] In this embodiment, the tool body 1 is also provided with a test groove 4 with an upward opening, and the test groove 4 can be used to place the micro speaker to be tested. The test groove 4 is arranged at the central position of the runway circle formed by the annular groove 3. Correspondingly, the inside of the tool body 1 is also provided with a first channel and a second channel, so as to perform a corresponding real water test on the micro speaker. Figures 2 to 4 The test groove 4, the first channel and the second channel are described in detail.

[0053] In this embodiment, if Figure 4 As shown, the shape of the test groove 4 is similar to a rectangle with four curved corners. The test groove 4 extends along a first direction, which is the length direction of the tool body 1. The depth of the test groove gradually increases along the first direction, that is, the bottom of the test groove 4 is an inclined surface, and the height of the inclined surface gradually increases in the first direction. Figure 2 For example, the height of the groove bottom relative to the bottom surface of the tooling body 1 increases from left to right. A first opening 41 and a second opening 42 are provided at the groove bottom, and the first opening 41 is arranged at a position in the test groove that is higher than the groove depth of the second opening 42, that is, a second opening is provided on the left side (i.e., the lower side of the groove bottom), and the second opening is connected to one end of the second sub-channel, and a first opening is also provided on the right side (i.e., the higher side of the groove bottom), and the first opening is connected to the first channel.

[0054] In this embodiment, if Figure 4As shown, the first channel and the second channel extend from the bottom of the test groove 4 and extend to both sides respectively. The first channel includes two sub-channels with circular cross-sections, namely the first sub-channel 51 and the second sub-channel 52. The main part of the first sub-channel 51 extends along the width direction of the tooling body 1. One end of the first sub-channel 51 is connected to the first opening 41, and the other end opening of the first sub-channel 51 is arranged on a side surface of the tooling body. And at the opening at the other end of the first sub-channel 51, a first shielding portion 71 that is adapted to the shape and size of the opening is provided, and the first shielding portion 71 is a cylinder. The first shielding portion 71 of the cylinder is embedded in the opening at the other end of the first sub-channel to block the opening. The main part of the second sub-channel 52 extends along the length direction of the tooling body 1, and one end of the second sub-channel 52 is connected to the first sub-channel 51, as shown in FIG. Figure 4 As shown, the second sub-channel 52 extends from the middle position of the first sub-channel 51 and extends along the length direction of the tooling body 1. The second sub-channel 52 is provided with two opening sections at one end away from the first sub-channel 51, namely, the first opening section 521 and the second opening section 522. The opening of the first opening section 521 is arranged on the bottom surface of the tooling body 1, and the opening of the second opening section 522 is arranged on a side surface of the tooling body 1. The radius of the second opening section 522 is greater than the radius of the main part of the second sub-channel 52. At the opening of the second opening section 522, a second shielding portion 72 matching the shape and size of the second opening section 522 is arranged. The second shielding portion 72 is a cylinder. The opening of the second opening section 522 is blocked by embedding the cylindrical second shielding portion 72 into the second end opening.

[0055] The second channel includes two sub-channels with circular cross-sections, namely the third sub-channel 61 and the fourth sub-channel 62. The main part of the third sub-channel 61 extends along the width direction of the tooling body 1, and one end of the third sub-channel 61 is connected to the above-mentioned second opening, and the other end opening of the third sub-channel 61 is arranged on the side of the tooling body 1. It should be pointed out that the radius of the other end opening of the third sub-channel 61 is larger than the main part of the third sub-channel 61. At the other end opening of the third sub-channel 61, a third shielding portion 73 that is adapted to the shape and size of the other end opening of the third sub-channel 61 is arranged. The third shielding portion 73 is a cylinder. The cylindrical third shielding portion 73 is embedded in the other end opening of the third sub-channel 61 to block the opening. The main part of the fourth sub-channel 62 extends along the length direction of the tooling body 1, and one end of the fourth sub-channel 62 is connected to the third sub-channel 61. Figure 4As shown, the fourth sub-channel 62 extends from the middle position of the third sub-channel 61 and extends along the length direction of the tooling body 1. The fourth sub-channel 62 is provided with two opening sections at one end away from the third sub-channel 61, namely the third opening section 621 and the fourth opening section 622. The opening of the third opening section 621 is arranged on the bottom surface of the tooling body 1, and the opening of the fourth opening section 622 is arranged on one side surface of the tooling body 1, and the radius of the fourth opening section 622 is greater than the radius of the main part of the fourth sub-channel 62. At the opening of the fourth opening section 622, a fourth shielding portion 74 matching the shape and size of the fourth opening section 622 is arranged, and the fourth shielding portion 74 is a cylinder. The opening of the fourth opening section 622 is blocked by embedding the cylindrical fourth shielding portion 74 into the second end opening. It should be noted that the structures of the first channel and the second channel on the tooling body 1 are similar.

[0056] In addition, in this embodiment, the tool body 1 is further provided with a plurality of first through holes 11 and a plurality of second through holes 12. Figure 4 The above components are introduced in detail. Figure 4 As shown, two first through holes 11 are distributed at two corners of the tool body 1, and the other two are arranged near the side. The first through hole is composed of an upper part and a lower part. The diameter of the upper part (i.e., the first hole) is larger than the diameter of the lower part (i.e., the second hole). The first through hole is used for screws to pass through to fix the tool. In addition, two second through holes 12 are symmetrically distributed along the width direction of the tool body 1 with the test groove 4 as the central axis on the tool body 1. The axial cross section of the second through hole 12 is circular. The second through hole extends along the height direction of the tool body 1.

[0057] In summary, the test fixture provided by the utility model: an annular groove opening upward is provided on the fixture body, and the cross section of the annular groove in the direction perpendicular to the height of the fixture body gradually decreases upward along the height direction, that is, the structure of the axial cross section of the annular groove is a dovetail groove structure that is small at the top and large at the bottom. When it is necessary to test with the test fixture, the sealing ring is set in the annular groove. Since the structure of the axial cross section of the annular groove is no longer a traditional straight groove structure, but a dovetail groove structure that is small at the top and large at the bottom, therefore, setting the sealing ring in the annular groove of the dovetail groove structure can avoid the sealing ring being lifted and falling off during multiple real water tests, thereby causing sealing failure, which is helpful for acoustic performance testing.

[0058] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. A test tool, characterized in that: include: The tooling body and the sealing ring, the tooling body is provided with an annular groove opening upward, the cross section of the annular groove perpendicular to the height direction of the tooling body gradually decreases upward along the height direction; wherein the sealing ring is arranged on the annular groove.

2. The test tool according to claim 1, characterized in that: The annular groove includes two arc grooves and two parallel linear grooves. The two arc grooves are respectively arranged at two ends of the linear groove, and the two ends of the arc groove are respectively connected to the two linear grooves.

3. The test tool according to claim 1, characterized in that: The sealing ring is made of silicone.

4. The test tool according to claim 1, characterized in that: The tool body is also provided with a test groove opening upward, and the test groove is arranged in an annular area surrounded by the annular groove.

5. The test tool according to claim 4, characterized in that: The depth of the test groove gradually increases along the first direction, a first opening and a second opening are provided in the test groove, and the first opening is arranged at a position in the test groove at a higher depth than the second opening; The tool body is provided with a first channel and a second channel communicated with the outside, and the first channel is communicated with the first opening, and the second channel is communicated with the second opening.

6. The test tool according to claim 5, characterized in that: The first channel and the second channel are respectively arranged on two sides of the test groove.

7. The test tool according to claim 5, characterized in that: The first channel includes a first sub-channel and a second sub-channel which are interconnected, and an extension direction of the first sub-channel is arranged at an angle to an extension direction of the second sub-channel.

8. The test tool according to claim 7, characterized in that: The first end opening of the first sub-channel is communicated with the first opening, and the second end opening of the first sub-channel is arranged on a side surface of the tooling body.

9. The test fixture according to claim 8, characterized in that: One end of the second sub-channel is connected to the first sub-channel, and the other end is provided with a first opening section and a second opening section. The opening of the first opening section is arranged on the bottom surface of the tooling body, and the opening of the second opening section is arranged on a side surface of the tooling body.

10. The test fixture according to claim 9, characterized in that: The tooling body is further provided with a first shielding portion and a second shielding portion. The first shielding portion is embedded in the second end opening of the first sub-channel, and the second shielding portion is embedded in the opening of the second opening section.

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