Grommet

Abstract

To provide a grommet capable of suppressing discomfort due to a resonance phenomenon in a one side block pipe part.SOLUTION: A grommet comprises: a frustum-like frustum part 12 of which an inner diameter is gradually reduced; a penetration pipe part 14 which is provided at a small-diameter side of the frustum part 12, in which both ends are open, and which can penetrate a restiform body; a panel engagement part 18 which is provided to a large diameter side of the frustum part 12, and in which an inner peripheral edge of a penetration hole is engaged; and a one side block pipe 20 which is provided to the frustum part 12 and in which one end part is blocked, and is structured so as to be attached by engaging the panel engagement part 18 into a penetration hole formed in a dash panel. A pipe length L from a block part 22 to the open end of the one side block pipe 20 is formed in the length that a resonance frequency by the one side block pipe 20 is 2,000 Hz or less or 4,000 Hz or more.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a grommet that protects a wire harness that passes through a panel. [Background technology]

[0002] Various vehicles, such as automobiles, ships, and aircraft, are divided into a plurality of spaces by panels made of steel or the like, and devices arranged in different spaces are connected by wire harnesses passing through through holes formed in the panels. When wiring the wire harnesses through the through holes of such panels, grommets are provided in the through holes to prevent the wire harnesses from being damaged due to contact with the panel, and to prevent the intrusion of noise, water, dust, and the like through the through holes. For example, in a vehicle such as an automobile, the passenger compartment and the engine compartment are separated by a vehicle body panel such as a dash panel, and a wire harness is inserted through a cylindrical portion of a grommet attached to a through hole formed in the dash panel to connect a battery as a power supply source installed in the engine compartment to various electrical devices arranged in the passenger compartment to supply power (for example, Patent Document 1).

[0003] In addition to the main through-hole tubular portion (through-hole tubular portion) through which the above-mentioned wire harness is inserted, some grommets are provided with an auxiliary tubular portion (one-side closed tubular portion) through which a wire harness, piping, etc. can be inserted separately when necessary, such as when adding equipment to the vehicle interior, to enhance expandability. Such an auxiliary tubular portion is formed with one end closed, and when the auxiliary tubular portion is not in use, it separates the inside and outside of the vehicle body panel to prevent sound, etc. from the outside of the vehicle from entering the inside of the vehicle, and when necessary, such as when adding equipment, the closed end is cut off and the necessary wire harness or piping is inserted through the auxiliary tubular portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-159890 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, although a grommet having an auxiliary tubular portion can increase the expandability by the auxiliary tubular portion, when the auxiliary tubular portion is not in use, for example, the driving noise of the engine or motor, which is a power source, or road noise during driving enters the inside of the auxiliary tubular portion from the open end, and the sound generated by the resonance phenomenon in the auxiliary tubular portion is transmitted to the vehicle interior, causing discomfort to the occupants and impairing the quietness of the interior. Although it is possible to prevent such a resonance phenomenon by attaching a silencer, such as that disclosed in Patent Document 1, to the open end of the auxiliary tubular portion, the need to prepare and attach a separate silencer makes the work complicated, and there is a concern that the silencer may fall off due to vibrations during driving.

[0006] That is, an object of the present invention is to provide a grommet having a one-side closed tube portion that can suppress the discomfort caused by the resonance phenomenon. [Means for solving the problem]

[0007] In order to overcome the above problems and achieve the intended purpose, the first means is: A grommet to be attached to a through hole formed in a panel, A frustum-shaped portion having an inner diameter gradually decreasing; a through-hole tube portion provided on the small diameter side of the frustum portion, having both ends open, through which a cord-like body can be inserted; a panel engagement portion provided on a large diameter side of the frustum portion and engaging with an inner peripheral edge of the through hole; A one-sided closed tube portion is provided on the frustum portion and one end of the one-sided closed tube portion is closed. The gist of the invention is that the length of the tube from the closed portion of the one-side closed tube portion to the open end is set to a length such that the resonance frequency of the one-side closed tube portion is 2,000 Hz or less or 4,000 Hz or more. In this way, by forming the pipe length from the closed part to the open end of the one-side closed pipe section to be 20 mm or less or 45 to 60 mm, the resonance frequency of the one-side closed pipe section can be set to 2,000 Hz or less or 4,000 Hz or more. This makes it difficult to hear the sound generated by the resonance phenomenon in the one-side closed pipe section, so that discomfort to personnel can be reduced without using a separate part such as a silencer. In addition, since there is no need to use a silencer, the work of attaching the grommet to the panel can be improved, and unnecessary materials generated when using the one-side closed pipe section, such as when adding equipment, can be reduced.

[0008] The second method is The one-side closed tube section is formed so that its length can be expanded or contracted, and the length of the tube in a contracted state is set so that the resonance frequency of the one-side closed tube section is 2,000 Hz or less or 4,000 Hz or more. In this way, since the one-sided closed pipe section can be expanded and contracted, the sound generated by the resonance phenomenon can be made difficult to hear by shortening the one-sided closed pipe section when not in use, and the one-sided closed pipe section can be extended when in use to improve the retention of wire harnesses, piping, etc. that are inserted into the one-sided closed pipe section.

[0009] The third method is The one-side closed pipe portion includes a base pipe portion connected to the frustum portion, a closed pipe portion whose protruding end side is closed by the closing portion, and a connecting pipe portion connecting the base pipe portion and the closed pipe portion, The gist of the invention is that the length of the one-side closed pipe section can be extended or shortened by transforming the connecting pipe section into a first state in which it is positioned so as to be connected to the outside of the base pipe section, and a second state in which it is positioned inside the base pipe section, inverted from the first state. In this manner, the length of the one-side closed pipe section can be easily changed by pushing the closed pipe section into or pulling it out of the base pipe section.

[0010] The fourth measure is The one-side closed pipe section is formed so that the pipe length can be expanded or contracted on both ends of the closed end and the open end closed by the closing section. In this way, by making it possible to expand and contract the pipe length at both ends, the closed end and the open end, the one-sided closed pipe section can be shortened when not in use to make it difficult to hear sounds generated by resonance, and the one-sided closed pipe section can be extended when in use to improve the retention of wire harnesses, piping, etc. that are inserted through the one-sided closed pipe section. Effect of the Invention

[0011] According to the present invention, it is possible to suppress discomfort caused by the resonance phenomenon in the one-side closed tube portion when not in use. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a grommet according to the present invention; [Diagram 2] FIG. 1 is a schematic perspective view of a grommet according to a first embodiment. [Diagram 3] FIG. 1 is a vertical cross-sectional view of a grommet according to a first embodiment. [Figure 4] FIG. 1 is a graph showing equal cloud curves. [Diagram 5] 13A is an enlarged longitudinal cross-sectional view of a main portion of a grommet according to a second embodiment, in which (a) shows a state in which the one-side closed pipe portion is in a standard state, and (b) shows a state in which the one-side closed pipe portion is in a shortened state. [Figure 6] 13A is an enlarged longitudinal cross-sectional view of a main portion of a grommet according to a third embodiment, in which (a) shows a state in which the one-side closed pipe portion is in a standard state, and (b) shows a state in which both ends of the one-side closed pipe portion are in a shortened state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Next, a grommet according to the present invention will be described below with reference to the accompanying drawings. In this embodiment, a grommet to be attached to a through hole provided in a dash panel of a vehicle such as an automobile will be described as an example.

[0014] (First embodiment) As shown in Fig. 1, this grommet 10 protects a wire harness WH that is routed through a through hole 50a provided in a dash panel 50 that separates an engine room ER provided in front of a passenger compartment HR of an automobile MT from the inside of the passenger compartment HR, and is made of an elastic material that can be elastically deformed, such as EPDM rubber. As shown in Fig. 2 or 3, this grommet 10 includes a frustum-shaped frustum portion 12 whose inner diameter gradually decreases, and a through-shaped tube portion 14 provided so as to protrude in the axial direction of the frustum portion 12 from the end of the small diameter side of the frustum portion 12. The through-shaped tube portion 14 is formed in a cylindrical shape with both ends open, with the protruding end being open and the base end side connected to the frustum portion 12 being open so as to connect to the inside of the frustum portion 12, and the frustum portion 12 and the through-shaped tube portion 14 form a funnel shape. This allows a wire harness WH to be passed through the inside of the frustum portion 12 from the engine compartment ER side and then inserted into the through-hole pipe portion 14 so as to be wired to the passenger compartment HR side.

[0015] In addition, the grommet 10 is provided with an annular large diameter portion 16 formed at the large diameter end of the frustum portion 12 with a diameter larger than that of the through hole 50a of the dash panel 50, and a groove-shaped panel engagement portion 18 with which the inner peripheral edge of the through hole 50a of the dash panel 50 can engage is provided between the large diameter end of the frustum portion 12 and the large diameter portion 16. Here, the outer peripheral edge of the large diameter end of the frustum portion 12 is formed to have a diameter larger than that of the through hole 50a of the dash panel 50, and the panel engagement portion 18 is formed with a diameter approximately equal to that of the through hole 50a. That is, when the small diameter side (the through-shaped tube portion 14) of the frustum portion 12 is inserted into the through hole 50a from one side of the dash panel 50 (for example, the engine room ER side), the frustum portion 12 elastically deforms, and the inner peripheral edge of the through hole 50a engages with the panel engagement portion 18, thereby attaching the grommet 10 to the dash panel 50. In this way, by inserting the wire harness WH through the grommet 10 attached to the through hole 50a of the dash panel 50, the wire harness WH is protected from the edge of the through hole 50a of the dash panel 50 and water, dust, etc. are prevented from entering the passenger compartment through the through hole 50a.

[0016] In addition, the truncated cone portion 12 of the grommet 10 is provided with a one-side closed tube 20 with one end closed, extending in the axial direction of the truncated cone portion 12. The one-side closed tube 20 includes a closed tube portion 24 that extends in the axial direction of the truncated cone portion 12 so as to connect to the outer surface side (small diameter side) of the truncated cone portion 12 and has a protruding end side closed by a closing portion 22, and an open tube portion 26 that extends in the axial direction of the truncated cone portion 12 so as to connect to the inner surface side of the truncated cone portion 12 and has both ends open. That is, the one-side closed tube 20 is formed so that the closed tube portion 24 and the open tube portion 26 communicate with each other and form a closed tube with one end closed by the closing portion 22. In addition, the closed tube portion 24 is provided with a flange portion 28 that protrudes in a radially outward circular shape at the protruding end of the closed tube portion 24 and at a position spaced apart from the protruding end toward the base end side. The blocking portion 22 of the blocking pipe portion 24 is positioned closer to the protruding end of the blocking pipe portion 24 than between the two flange portions 28, and by cutting the one-side blocking pipe 20 at the gap 28a between the two flange portions 28, the blocking portion 22 can be removed and a wire harness WH or other piping can be inserted into the one-side blocking pipe 20.

[0017] The one-side closed tube 20 is a closed tube with one end closed by a closed portion 22, and a resonance phenomenon occurs when sound enters from the open end (the end of the open tube portion 26). Here, sounds that humans can hear (audible range) are generally in the frequency range of 20 Hz to 20,000 Hz, and it is known that the sense of loudness of a sound perceived by humans varies depending on the frequency even if the physical sound pressure is the same. An equal loudness curve, which represents the relationship between the frequency and sound pressure at which humans perceive a sound as being equal loudness, is standardized in the international standard ISO 226:2003 (see FIG. 4). That is, this equal loudness curve shows that sounds in the audible range, particularly those in the frequency range of 2,000 Hz to 4,000 Hz, are particularly easy for the human ear to hear. In other words, it can be seen that sounds in the frequency range of 2,000 Hz to 4,000 Hz are easily perceived by humans even if they have a slight sound pressure, which impairs quietness and causes discomfort to humans.

[0018] Therefore, the pipe length L (length from the pipe inner surface side of the closed portion 22 to the open end of the open pipe portion 26) of the one-side closed pipe 20 in the grommet 10 according to the present invention is set so that the resonance frequency f (Hz) of the sound incident on the one-side closed pipe 20 is F<2,000 Hz or F>4,000 Hz. Here, the resonance frequency f (Hz) of a closed pipe with one end closed can be calculated by the formula (1): f=(2n-1)V / 4L, where V (m / s) is the sound speed, L (m) is the pipe length, and n is the order of resonance. Here, Table 1 shows the relationship between the pipe length L and the resonance frequency in a standard environment (standard atmosphere (1 atmospheric pressure, 15°C), sound speed V=340 m / s) in which a vehicle using the grommet 10 of the present invention is used.

[0019] [Table 1]

[0020] That is, the one-side closed pipe 20 of the grommet 10 is formed so that the pipe length L is in the range of L≦20 mm and 45 mm≦L≦60 mm, so that the resonance frequency of the one-side closed pipe 20 in standard atmosphere when the one-side closed pipe 20 is not used can be 2,000 Hz or less or 4,000 Hz or more. Specifically, in this embodiment, the pipe length L is set to 60 mm. This makes it difficult to hear the sound generated by the resonance phenomenon in the one-side closed pipe 20, and as a result, the discomfort given to the occupants can be suppressed and the quietness in the vehicle interior HR can be increased. That is, the discomfort given to the occupants can be suppressed without attaching a separate part such as a silencer to the grommet 10. In addition, since there is no need to use a silencer, the installation work of the grommet 10 on the panel can be improved and unnecessary objects generated when the one-side closed pipe 20 is used, such as when adding equipment, can be reduced. Furthermore, since there is no need to attach a silencer to the one-side closed pipe 20, there is no risk of the silencer falling off due to external factors such as vibrations during driving, and good quietness can be maintained.

[0021] (Second Example) Next, a grommet according to a second embodiment will be described. The basic configuration of the grommet according to the second embodiment is basically the same as the configuration of the grommet 10 according to the first embodiment described above, but differs in the configuration of the one-side closed pipe 20. Therefore, in the following description, the configuration different from the grommet 10 according to the first embodiment will be described, and the common configuration will be assigned the same reference numerals and description thereof will be omitted.

[0022] The one-side closed pipe section 30 of the grommet 10 according to the second embodiment includes a base pipe section 32 having both open ends extending in the axial direction of the frustum section 12 so as to be connected to the outer surface side (small diameter side) of the frustum section 12, a closed pipe section 34 having a protruding end side closed by a closing section 22, and a connecting pipe section 36 connecting the base pipe section 32 and the closed pipe section 34, and is formed so as to form a series of tubes in which the base pipe section 32, the closed pipe section 34, and the connecting pipe section 36 are mutually connected on the outer surface side of the frustum section 12. That is, the connecting pipe section 36 is provided so as to connect the open end (protruding end) of the base pipe section 32 and the open end of the closed pipe section 34. The base pipe section 32, the closed pipe section 34, and the connecting pipe section 36 are formed so as to have the same axis. In addition, as in the first embodiment, an open tube section 26 with open ends is provided on the inner surface of the frustum section 12, and the open tube section 26 is formed so as to communicate with the base tube section 32 and form a closed tube with one end blocked by the blocking section 22.

[0023] Here, the connecting pipe section 36 is formed so that its outer diameter is smaller than the inner diameter of the base pipe section 32, and the blocking pipe section 34 is formed so that its outer diameter is smaller than the inner diameter of the connecting pipe section 36. That is, in a standard state (first state, see FIG. 5(a)) in which the connecting pipe section 36 is positioned so as to be connected to the outside of the base pipe section 32, by pushing the blocking pipe section 34 from its protruding end side (blocked end side) toward its base end side, the connecting pipe section 36 is inverted and positioned inside the base pipe section 32, and can be deformed to a contracted state (second state, see FIG. 5(b)) in which the blocking pipe section 34 is positioned inside the inverted connecting pipe section 36, and by pulling the blocking pipe section 34 from its base end side toward the protruding end side (blocked end side) in this second state, the connecting pipe section 36 can be deformed to the standard state in which it is connected to the outside of the base pipe section 32. In this way, the one-side occluded pipe 20 of the grommet 10 according to the second embodiment is capable of expanding and contracting its pipe length L. Furthermore, the flange portion 28 provided on the protruding end side of the occluding pipe portion 34 is located outside the base pipe portion 32 and the connecting pipe portion 36 in a contracted state, and the occluding pipe portion 34 can be easily pulled out by pinching the flange portion 28.

[0024] The one-side closed pipe 20 of the grommet 10 according to the second embodiment is formed so that its pipe length L in the shortened state is in the range of L≦20 mm and 45 mm≦L≦60 mm, and specifically, in this embodiment, the pipe length L in the shortened state is formed to be 50 mm. By setting the pipe length L of the one-side closed pipe 20 in this manner, the resonance frequency of the one-side closed pipe 20 in standard atmosphere when not in use can be set to 2,000 Hz or less or 4,000 Hz or more. As a result, by shortening the one-side closed pipe 20 when not in use, it is possible to make it difficult to hear the sound generated by the resonance phenomenon in the one-side closed pipe 20, and as a result, it is possible to suppress the discomfort given to the occupants and increase the quietness in the cabin, and other actions and effects similar to those of the grommet 10 according to the first embodiment can be expected. Then, when inserting a wire harness WH, piping, etc. into the one-side closed pipe 20 when adding equipment, etc., by setting the one-side closed pipe 20 to the standard state (extended state), it is possible to ensure a sufficient pipe length of the one-side closed pipe 20 and improve the retention of the wire harness WH, piping, etc. inserted into the one-side closed pipe 20. Also, by pushing the closed pipe portion 34 into or pulling it out of the base pipe portion 32, the pipe length of the one-side closed pipe 20 can be easily changed, improving workability.

[0025] (Third Example) Next, a grommet 10 according to a third embodiment will be described. The basic configuration of the grommet 10 according to the third embodiment is basically the same as the configuration of the grommet according to the second embodiment described above, but differs in the configuration of the one-side closed tube. Therefore, in the following description, configurations different from the grommet 10 according to the second embodiment will be described, and common configurations will be denoted by the same reference numerals and description thereof will be omitted.

[0026] The one-side closed pipe 40 of the grommet 10 according to the third embodiment is configured so that the pipe length L can be changed on both the closed end side closed by the closing portion 22 and the open end side. Specifically, the one-side closed pipe 40 of the grommet 10 includes a base pipe portion 32, a closing pipe portion 34, and a connecting pipe portion 36 (hereinafter, referred to as a first connecting pipe portion in the third embodiment) on the outer surface side of the frustum portion 12, as in the second embodiment described above. In the following description, a reference state in which the first connecting pipe portion 36 is positioned so as to be connected to the outside of the base pipe portion 32 is defined as a first reference state, and a contracted state in which the first connecting pipe portion 36 is inverted and positioned inside the base pipe portion 32 and the closing pipe portion 34 is positioned inside the inverted first connecting pipe portion 36 is defined as a first contracted state.

[0027] On the inner surface side of the frustum portion 12, there are provided a first open tube portion 42 connected to the frustum portion 12, a second connecting tube portion 44 provided at the protruding end of the first open tube portion 42 and extending in the axial direction of the frustum portion 12, and a second open tube portion 46 provided at the protruding end of the second connecting tube portion 44 and extending in the axial direction of the frustum portion 12. The first open tube portion 42, the second connecting tube portion 44, and the second open tube portion 46 are each formed so that their axes coincide with each other and both ends are open to form a series of tubes that communicate with each other, and the first open tube portion 42 is formed so as to communicate with the base tube portion 32 and form a closed tube in which one end of the one-side closed tube 40 is closed by the closing portion 22.

[0028] Here, the second connecting pipe portion 44 is formed so that its outer diameter is smaller than the inner diameter of the first open pipe portion 42, and the second open pipe portion 46 is formed so that its outer diameter is smaller than the inner diameter of the second connecting pipe portion 44. That is, in a second reference state (third state, see FIG. 6(a)) in which the second connecting pipe portion 44 is positioned so as to be connected to the outside of the first open pipe portion 42, the second open pipe portion 46 can be pushed in from its protruding end side (open end side) toward its base end side, whereby the second connecting pipe portion 44 is inverted and positioned inside the first open pipe portion 42 and can be deformed to a second shortened state (fourth state, see FIG. 6(b)) in which the second open pipe portion 46 is positioned inside the inverted second connecting pipe portion 44, and by pulling the second open pipe portion 46 from its base end side toward the protruding end side in this second state, the second connecting pipe portion 44 can be deformed to the second reference state in which the second connecting pipe portion 44 is connected to the outside of the first open pipe portion 42. In this way, the one-side closed pipe 40 of the grommet 10 according to the third embodiment is capable of expanding and contracting the pipe length L at both ends (closed end and open end). In addition, a flange portion 48 that protrudes radially outward in a circular ring shape is provided on the protruding end side of the second open pipe portion 46, and this flange portion 48 is positioned outside the first open pipe portion 42 and the second connecting pipe portion 44 in the second shortened state, so that the second open pipe portion 46 can be easily pulled out by pinching the flange portion 48.

[0029] The one-side closed tube 40 of the grommet 10 according to the third embodiment is formed so that its tube length L is in the range of L≦20 mm, 45 mm≦L≦60 mm in at least one of the first and second contracted states. Specifically, in this embodiment, the tube length L is formed to be 50 mm in the first and second contracted states. By setting the tube length L of the one-side closed tube 40 in this manner, the resonance frequency of the one-side closed tube 40 in standard atmosphere when not in use can be set to 2,000 Hz or less or 4,000 Hz or more. As a result, by shortening the one-side closed tube 40 when not in use, it is possible to make it difficult to hear the sound generated by the resonance phenomenon in the one-side closed tube 40, which can suppress the discomfort given to the occupants and increase the quietness in the cabin, and other actions and effects similar to those of the grommet 10 according to the first embodiment can be expected. When inserting a wire harness WH, piping, etc. into the one-side closed pipe 40 for adding equipment, etc., the one-side closed pipe 40 can be set in the first reference state and the second reference state (extended state) to ensure a sufficient pipe length of the one-side closed pipe 40 and improve the retention of the wire harness WH, piping, etc. inserted into the one-side closed pipe 40. Also, by pushing or pulling the closed pipe portion 34 into or out of the base pipe portion 32 or the second open pipe portion 46 into or out of the first open pipe portion 42, the pipe length of the one-side closed pipe 40 can be easily changed, improving workability.

[0030] Furthermore, if the tube length can be changed at both the closed end and the open end of the one-side closed tube 40, and the resonance frequency of the one-side closed tube 40 is set to 2,000 Hz or less or 4,000 Hz or more by manipulating one end side to put it into a shortened state (first shortened state or second shortened state), the workability of installing the grommet 10 can be further improved compared to a case where both ends are manipulated to put it into a shortened state (first shortened state and second shortened state). Furthermore, with a configuration in which both ends of the one-side closed tube 40 are manipulated to put it into a shortened state (first shortened state and second shortened state), the one-side closed tube 40 can be made more compact when not in use, and interference of the one-side closed tube 40 with other components can be prevented.

[0031] (Example of change) The configuration of the embodiment is not limited to the above, and can be modified as follows, for example. (1) Although the grommet has one one-side closed tube, the grommet may have a plurality of one-side closed tubes. Also, the plurality of one-side closed tubes provided in the grommet do not need to have the same configuration, and one-side closed tubes of different configurations, such as the one-side closed tube 20 according to the first embodiment and the one-side closed tube 30 according to the second embodiment, may be provided. (2) The configuration for enabling the length of the one-side closed tube to be extended or contracted is not limited to the configurations shown in the second and third embodiments, but the one-side closed tube may be formed into a bellows shape, and various conventionally known configurations for adjusting the length of the tubular body can be adopted. (3) In the second embodiment, the tube length is configured to be extendable at the closed end of the one-side closed tube 30, and in the third embodiment, the tube length is configured to be extendable at both the closed end and the open end of the one-side closed tube 40, but the tube length may be configured to be extendable only at the open end of the one-side closed tube. [Explanation of symbols]

[0032] 10 grommet, 12 frustum portion, 14 through-hole tube portion, 18 panel engagement portion 20, 30, 40 one-side closed pipe section, 22 closed section, 32 base pipe section, 34 closed pipe section, 36 Connection pipe section

Claims

1. A grommet to be attached to a through hole formed in a panel, One end of the tube is closed, and the tube length is extendable and retractable. The one-side closed pipe portion includes a base pipe portion, a closed pipe portion whose protruding end side is closed by a closing portion, and a connecting pipe portion connecting the base pipe portion and the closed pipe portion, A grommet characterized in that the pipe length of the one-side closed pipe section can be expanded or contracted by deforming between a first state in which the connecting pipe section is positioned so as to be connected to the outside of the base pipe section, and a second state in which the connecting pipe section is inverted from the first state and positioned inside the base pipe section.

2. A grommet to be attached to a through hole formed in a panel, One end of the tube is closed, and the tube length is extendable and retractable. The grommet is characterized in that the one-side closed pipe portion is formed so that the pipe length can be expanded or contracted on both ends of the closed end and the open end closed by the closing portion.

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