Grommet

Abstract

To provide a grommet capable of suppressing breakage of a lock part even when excessive force is applied to the lock part in a lock release direction.SOLUTION: A grommet 10 includes a grommet body 11 formed of a flexible material and holding an electric wire W passing through a through-hole 2 in a vehicle body panel 1, and an inner member 30 formed of a material having higher rigidity than the grommet body 11 and fitted into the through-hole 2. The inner member 30 has an annular inner body part 32, and a lock part 40 for locking the inner body part 32 to the peripheral edge of the through-hole 2 when a part of the inner body part 32 is inserted into the through-hole 2. The grommet body 11 has a regulating protrusion 50 which is formed on the outer periphery of the grommet body 11 and comes into contact with the lock 40 when the lock 40 is displaced inward in the radial direction of the grommet body 11.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Conventionally, grommets are attached to the periphery of a through hole formed in a plate material to protect the electric wire from the periphery of the through hole when the electric wire is passed through the through hole. Patent Document 1 discloses a technology related to a grommet including a grommet body that holds the electric wire when the electric wire is passed through a through hole in a vehicle body panel serving as a mounting member, and an inner member that supports the grommet body and is held on the periphery of the through hole. The grommet body disclosed in Patent Document 1 is made of, for example, soft rubber, and the inner member (grommet inner) is made of a material that is more rigid than the grommet body, for example, synthetic resin. The inner member disclosed in Patent Document 1 also has an inner body, multiple flanges, a locking portion, and an elastically deforming portion. With the inner member disclosed in Patent Document 1, even if the locking portion is unintentionally displaced in the unlocking direction, the restoring force of the elastically deforming portion can return the displacement of the locking portion, thereby preventing the inner member from being unintentionally removed from the through hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-129317 Summary of the Invention [Problem to be solved by the invention]

[0004] In the grommet disclosed in Patent Document 1, the aforementioned elastic deformation portion is formed on the inner member side, which is made of synthetic resin, for example. Therefore, if excessive force is applied to the locking portion, the elastic deformation portion may not be able to support this excessive force, and the locking portion may be damaged.

[0005] The present invention has been made in consideration of the problems inherent in the prior art, and an object of the present invention is to provide a grommet that can prevent damage to the locking portion even when an excessive force is applied to the locking portion in the unlocking direction. [Means for solving the problem]

[0006] A grommet according to one aspect of the present invention comprises a grommet body formed from a flexible material and holding an electric wire passing through a through hole in a mounting member, and an inner member formed from a material more rigid than the grommet body and fitted into the through hole, the inner member having an annular inner body portion and a locking portion that engages the inner body portion with the periphery of the through hole when a portion of the inner body portion is inserted into the through hole, and the grommet body having a regulating protrusion formed on the outer periphery of the grommet body and that comes into contact with the locking portion when the locking portion is displaced radially inward of the grommet body. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a grommet that can prevent damage to the locking portion even when an excessive force is applied to the locking portion in the unlocking direction. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view showing an example of a grommet according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic perspective view showing a grommet body according to the embodiment. [Figure 3] FIG. 2 is a schematic plan view illustrating an example of a grommet according to the present embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The grommet according to the present embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions.

[0010] FIG. 1 is a schematic perspective view of a grommet 10 according to this embodiment, and FIG. 2 is a schematic perspective view of a grommet body 11 according to this embodiment. As an example, the grommet 10 is attached to the periphery of a through-hole 2 formed in advance in a vehicle body panel 1 serving as a mounting member, and protects an electric wire W that has passed through the through-hole 2 from the periphery of the through-hole 2. In this embodiment, the opening shape of the through-hole 2 is circular. The electric wire W may be a wire harness serving as an assembly of electric wires. In the following description, "upper" refers to the side facing the through-hole 2 when the grommet 10 is attached to the periphery of the through-hole 2, and "lower" refers to the opposite side.

[0011] FIG. 3 is a schematic plan view of the grommet 10 according to this embodiment, and FIG. 4 is a cross-sectional view showing a main part of the grommet 10 according to this embodiment.

[0012] The grommet 10 includes a grommet body 11 and an inner member 30, also called an inner protector.

[0013] The grommet body 11 is a cylindrical member that holds the electric wire W routed on its inner periphery. The grommet body 11 is made of a flexible material such as rubber. The grommet body 11 includes a large-diameter cylindrical portion 12, a first small-diameter cylindrical portion 13, and a second small-diameter cylindrical portion 14.

[0014] The large-diameter cylindrical portion 12 is connected to the inner member 30. The outer diameter of the large-diameter cylindrical portion 12 is larger than the opening diameter of the through-hole 2. The large-diameter cylindrical portion 12 includes a lip portion 17 and a recessed portion .

[0015] The lip portion 17 is an annular sealing portion that protrudes from the outer peripheral edge surface 12a facing the vehicle body panel 1 toward the vehicle body panel 1. The lip portion 17 may be composed of an inner peripheral lip portion 17a and an outer peripheral lip portion 17b. When the grommet 10 is attached to the peripheral edge of the through hole 2, the inner peripheral lip portion 17a and the outer peripheral lip portion 17b elastically deform in a direction that causes them to fall toward the outer peripheral edge surface 12a, and come into close contact with the peripheral surface of the through hole 2 on one surface of the vehicle body panel 1. This prevents water and other contaminants from entering the interior of the grommet 10 from the outside through a gap between the lip portion 17 and the surface of the vehicle body panel 1 that faces the lip portion 17.

[0016] The recessed portion 18 is formed on the outer circumferential side of the large-diameter cylindrical portion 12, and engages with a protruding portion 33a formed on the inner member 30 when the inner member 30 is connected to the large-diameter cylindrical portion 12.

[0017] The first small-diameter cylindrical portion 13 is continuous with the large-diameter cylindrical portion 12 on the side opposite to the side facing the vehicle body panel 1 via a first expanded-diameter cylindrical portion (not shown) and a bellows-shaped cylindrical portion 20, and holds the electric wire W on its inner circumferential side. The first small-diameter cylindrical portion 13 is disposed on one side (the engine compartment side) of the opening of the through-hole 2 and has an inner surface that contacts the outer circumferential surface of the electric wire W over a predetermined length. The inner diameter of the first small-diameter cylindrical portion 13 is smaller than the inner diameter of the large-diameter cylindrical portion 12 and is slightly smaller than or substantially equal to the outer diameter of the electric wire W. This prevents water and other contaminants from penetrating from the outside to the inside of the grommet 10 through a gap between the inner surface of the first small-diameter cylindrical portion 13 and the outer circumferential surface of the electric wire W. The first small-diameter cylindrical portion 13 is made of a flexible material and therefore deforms in accordance with changes in the position of the electric wire W. Further, an annular first seal portion (not shown) that seals the gap between the inner circumferential surface of the first small diameter cylindrical portion 13 and the electric wire W may be provided on the inner circumferential surface of the first small diameter cylindrical portion 13.

[0018] The second small-diameter cylindrical portion 14 is continuous with the side of the large-diameter cylindrical portion 12 facing the vehicle body panel 1 via the second expanded-diameter cylindrical portion 21, and holds the electric wire W on its inner peripheral side. This second small-diameter cylindrical portion 14 is disposed on the other side (inside the vehicle cabin) of the opening of the through-hole 2, and has an inner surface that contacts the outer peripheral surface of the electric wire W over a predetermined length. The inner diameter of the second small-diameter cylindrical portion 14 is smaller than the inner diameter of the large-diameter cylindrical portion 12, and is slightly smaller than or substantially equal to the outer diameter of the electric wire W. This prevents water and other contaminants from entering the interior of the grommet 10 from the outside through a gap between the inner surface of the second small-diameter cylindrical portion 14 and the outer peripheral surface of the electric wire W. The second small-diameter cylindrical portion 14 is made of a flexible material, and therefore deforms in accordance with changes in the position of the electric wire W. Also, an annular second seal portion 14a may be provided on the inner peripheral surface of the second small diameter cylindrical portion 14 to seal the gap between the inner peripheral surface of the second small diameter cylindrical portion 14 and the electric wire W. Furthermore, a tongue portion (not shown) for winding a tape may be protruded from the tip of the second small diameter cylindrical portion 14.

[0019] The inner member 30 is an annular member that supports the grommet body 11 and is held on the periphery of the through hole 2. The inner member 30 is made of a material, such as synthetic resin, that is more rigid than the grommet body 11. The inner member 30 is also composed of a pair of members that are divided into two by an imaginary plane that includes the central axis of the inner member 30 itself, that is, a combination of a first inner member 31a and a second inner member 31b.

[0020] The inner member 30 has an inner main body portion 32 which is an annular structure made up of a plurality of wall portions as a whole.

[0021] The inner main body portion 32 includes, for example, an outer peripheral wall 32a, an upper wall 32b, and an inner peripheral wall 32c. The outer peripheral wall 32a is a wall that faces the peripheral edge of the through hole 2 along the planar direction of the vehicle body panel 1 when the grommet 10 is attached to the peripheral edge of the through hole 2. The upper wall 32b is a wall that is continuous with the upper peripheral edge of the outer peripheral wall 32a and extends toward the inner peripheral side. The inner peripheral wall 32c is a wall that is continuous with the inner peripheral edge of the upper wall 32b and is approximately parallel to the outer peripheral wall 32a.

[0022] The inner main body portion 32 has a protrusion 33a that aligns with the position of a recess 18 that is pre-formed in the large-diameter cylindrical portion 12 of the grommet body 11 and engages with the recess 18. The engagement between the protrusion 33a and the recess 18 prevents the inner member 30 from rotating relative to the grommet body 11 around the central axis CL of the large-diameter cylindrical portion 12. The protrusion 33a may be formed on each of the first inner member 31a and the second inner member 31b. Alternatively, the large-diameter cylindrical portion 12 of the grommet body 11 may be formed with a plurality of recesses 18 that correspond to the respective protrusions 33a.

[0023] When the inner member 30 is a combination of a pair of members, a first inner member 31a and a second inner member 31b, the first inner member 31a and the second inner member 31b may have the same semi-annular shape. Furthermore, the first inner member 31a and the second inner member 31b include two side walls 32d that abut against each other in the circumferential direction when combined with each other. Of the two side walls 32d, one side wall 32d is provided with a claw portion 34, and the other side wall 32d is provided with a groove portion 35. When the first inner member 31a and the second inner member 31b are combined with each other, the claw portion 34 of the first inner member 31a fits into the groove portion 35 of the second inner member 31b, and the claw portion 34 of the second inner member 31b fits into the groove portion 35 of the first inner member 31a.

[0024] The first inner member 31a and the second inner member 31b may be connected, for example, via a hinge portion instead of the connection mechanism using the claw portion 34 and the groove portion 35. Furthermore, although the present embodiment illustrates a case where the inner member 30 is divided into two inner members, it may be divided into three or more inner members.

[0025] The inner member 30 also has a plurality of locking portions 40 that lock the inner main body portion 32 to the periphery of the through hole 2 when a portion of the inner main body portion 32 is inserted into the through hole 2. These locking portions 40 are also referred to as inner locks. In this embodiment, the locking portions 40 are provided at four locations equally spaced apart in the circumferential direction of the entire inner member 30. That is, the first inner member 31a and the second inner member 31b each have two locking portions 40. The number of locking portions 40 provided is not particularly limited and may be any number other than four.

[0026] The locking portion 40 includes a locking claw 41 .

[0027] The locking claws 41 are provided along the outer peripheral wall 32a of the inner main body portion 32 and elastically deform in a direction connecting the inside and outside of the outer peripheral wall 32a. The locking claws 41 have protrusions that contact or engage with the peripheral edge of the through hole 2. The state in which the protrusions engage with the peripheral edge of the through hole 2 refers to the state of the protrusions relative to the through hole 2 when the locking portion 40 locks the inner main body portion 32 to the peripheral edge of the through hole 2, i.e., when the grommet 10 is attached to the peripheral edge of the through hole 2. The protrusions protrude outward from a ridge line along the circumferential direction of the outer peripheral wall 32a as their apex and are always located outside the outer periphery of the outer peripheral wall 32a. In other words, the elastic deformation of the locking claws 41 occurs due to the displacement of the protrusions as they contact the peripheral edge of the through hole 2. When the protrusion is engaged with the peripheral edge of the through hole 2, the peripheral edge of the through hole 2 fits into the lower end groove of the protrusion, thereby maintaining the inner main body portion 32 in a constant position relative to the peripheral edge of the through hole 2.

[0028] In addition, since the inner member 30 has locking portions 40 provided at four locations in the circumferential direction, each of the protrusions included in the total of four locking claws 41 protrudes along a radial direction based on the central axis of the inner main body portion 32.

[0029] Furthermore, ribs 36 are provided on the outer peripheral wall 32a of the inner main body portion 32 of the inner member 30 to prevent the inner member 30 from being attached in a tilted state relative to the grommet body 11. In the grommet 10 according to this embodiment, a pair of ribs 36 are formed on the outer peripheral wall 32a of the inner main body portion 32 of the inner member 30, with the locking claws 41 sandwiched between them, and a rib 36 is provided at a midpoint between adjacent locking claws 41 in the circumferential direction. In the grommet 10 according to this embodiment, the inner member 30 has the ribs 36 for preventing tilt, so that the inner peripheral surface of the through hole 2 comes into contact with the ribs 36, reducing the load applied to the locking claws 41.

[0030] Furthermore, the large-diameter cylindrical portion 12 of the grommet body 11 and the inner body portion 32 of the inner member 30 are each provided with alignment protrusions 18a, 37 to prevent the inner member 30 from being attached to the grommet body 11 in an incorrect orientation. In the grommet 10 according to this embodiment, the alignment protrusion 37 on the inner member 30 side is formed in a semicircular shape and is provided on the upper surface of the tip of the convex portion 33a. On the other hand, the alignment protrusion 18a on the grommet body 11 side is formed in a rectangular shape and is provided near the recess 18 in the large-diameter cylindrical portion 12 of the grommet body 11. In the grommet 10 according to this embodiment, the grommet body 11 and the inner member 30 each have alignment protrusions 18a, 37 to prevent incorrect assembly. This makes it possible to prevent the inner member 30 from being attached to the grommet body 11 in an incorrect orientation relative to the longitudinal direction (vertical direction) of the grommet body 11. In addition, by visually checking to see that the alignment protrusion 37 on the inner member 30 is abutting against the alignment protrusion 18a on the grommet body 11, incorrect assembly of the inner member 30 can be prevented.

[0031] In this embodiment, a restricting protrusion 50 is formed on the outer periphery of the grommet body 11. The restricting protrusion 50 comes into contact with the locking portion 40 of the inner member 30 when the locking portion 40 is displaced radially inward of the grommet body 11. The restricting protrusion 50 is formed to extend perpendicular to the axial direction (central axis CL) of the grommet body 11. The restricting protrusion 50 has a base 51 formed on the outer periphery of the grommet body 11, a flat rib portion 52 extending from the base 51 radially outward of the grommet body 11, and a contact surface portion 53 having a semicircular cross section formed at the tip of the rib portion 52. The rib portion 52 of the restricting protrusion 50 has an upper surface 52a and a lower surface 52b, which are configured to be substantially parallel to a horizontal plane (a plane extending radially along the inner body portion 32).

[0032] In this embodiment, a plurality of locking portions 40 are formed on the inner main body portion 32, whereas only one restricting protrusion portion 50 is formed on the grommet main body 11 so as to correspond to only one of the plurality of locking portions 40. Therefore, the restricting protrusion portion 50 is formed on the grommet main body 11 so as to face only one of the plurality of locking portions 40.

[0033] However, this is not limited to this embodiment, and the regulating protrusion portion 50 may be formed in multiple numbers on the grommet body 11, or may be formed on the grommet body 11 so as to correspond to all of the multiple locking portions 40.

[0034] In the grommet 10 according to this embodiment, a restricting protrusion 50 is formed on the grommet body 11, which is made of a flexible material, to prevent damage to the locking portion 40. Even if the locking portion 40 is accidentally pushed radially inward (in the unlocking direction) when fitting the inner member 30, which is made of synthetic resin or the like, the restricting protrusion 50 contacts and supports the locking portion 40. Therefore, even if the locking portion 40 is accidentally pushed when fitting the inner member 30, which is made of synthetic resin or the like, the contact with the restricting protrusion 50 restricts the displacement of the locking portion 40, thereby preventing damage caused by excessive radial inward displacement of the locking portion 40. Since the operator does not need to pay attention to the location to press when fitting the inner member 30, which is made of synthetic resin or the like, the workability when fitting the inner member 30 can be improved. Even if a load acts on the locking portion 40 during transportation of the wire harness or during assembly into a vehicle, the displacement of the locking portion 40 is restricted by contact with the restricting protrusion 50, thereby preventing damage caused by excessive radial inward displacement of the locking portion 40. Furthermore, even if an excessive force is applied to the locking portion 40 due to vibration, impact, or the like after assembly into a vehicle, the displacement of the locking portion 40 is restricted by contact with the restricting protrusion 50, thereby preventing damage caused by excessive radial inward displacement of the locking portion 40.

[0035] Next, the function of the grommet 10 will be described.

[0036] First, to assemble the grommet 10, a worker prepares the grommet body 11 with the electric wire W routed inside, and attaches the inner member 30 to the large-diameter cylindrical portion 12 of the grommet body 11. The inner member 30 is divided into a first inner member 31a and a second inner member 31b in advance. Therefore, if the electric wire W has already passed through the through-hole 2 in the vehicle body panel 1, the inner members can be combined with each other so as to sandwich the large-diameter cylindrical portion 12 of the grommet body 11 from both sides, making it easy to attach the inner member 30 to the large-diameter cylindrical portion 12 of the grommet body 11. Through this procedure, the grommet 10 is attached to the electric wire W.

[0037] Next, to attach the grommet 10 to the periphery of the through hole 2, if the electric wire W has not yet been inserted through the through hole 2, the worker inserts the electric wire W exposed from the second small-diameter tubular portion 14 of the grommet body 11 into the through hole 2. Next, the worker presses the entire grommet 10 toward the through hole 2 while inserting the inner body portion 32 of the inner member 30 into the through hole 2. At this time, each locking claw 41 of the locking portion 40 elastically deforms as its protrusion comes into contact with the periphery of the through hole 2 and displaces, allowing the inner body portion 32 to be inserted into the through hole 2. When the inner body portion 32 is inserted to the insertion completion position, each locking claw 41 elastically returns to its original position, thereby locking the inner body portion 32 to the periphery of the through hole 2. When the inner member 30 is in this locked state, the lip portion 17 of the grommet body 11 tightly contacts the periphery of the through hole 2 on the surface of the vehicle body panel 1. That is, the vehicle body panel 1 is clamped between the protrusion on the inner member 30 side and the lip portion 17 on the grommet body 11 side. As a result, the grommet 10 is attached to the periphery of the through hole 2 so as to close the through hole 2.

[0038] Next, the effects of the grommet 10 will be described.

[0039] As described above, the grommet 10 according to this embodiment includes a grommet body 11 formed from a flexible material and configured to hold an electric wire W passing through a through hole 2 in a mounting member (vehicle body panel 1). The grommet 10 includes an inner member 30 formed from a material having higher rigidity than the grommet body 11 and fitted into the through hole 2. The inner member 30 includes an annular inner body portion 32 and a locking portion 40 that locks the inner body portion 32 to the periphery of the through hole 2 when a portion of the inner body portion 32 is inserted into the through hole 2. The grommet body 11 includes a restricting protrusion 50 formed on the outer periphery of the grommet body 11 and that comes into contact with the locking portion 40 when the locking portion 40 is displaced radially inward of the grommet body 11.

[0040] In the grommet 10 according to this embodiment, a restricting protrusion 50 is formed on the grommet body 11 side, which is made of a flexible material, in order to prevent damage to the locking portion 40. Even if the locking portion 40 is accidentally pushed radially inward (in the unlocking direction) when fitting the inner member 30, which is made of a synthetic resin or the like, the restricting protrusion 50 comes into contact with the locking portion 40, preventing further displacement of the locking portion 40. Therefore, even if the locking portion 40 is accidentally pushed when fitting the inner member 30, which is made of a synthetic resin or the like, the displacement of the locking portion 40 is restricted by contact with the restricting protrusion 50, preventing damage caused by excessive radial inward displacement of the locking portion 40.

[0041] That is, by forming the restricting protrusion 50 on the grommet body 11 side, which is made of a flexible material, even if further force is applied to the locking portion 40 while the locking portion 40 is in contact with the restricting protrusion 50, the force can be released. Therefore, the shape of the restricting protrusion 50 formed on the grommet body 11 side is restored after excessive force is applied to the locking portion 40, and the function of the restricting protrusion 50 can be maintained. Furthermore, when the restricting protrusion is formed on the inner member side, which is made of synthetic resin or the like, it is necessary to form a hole in the inner member when the inner member is removed from the mold, which can reduce the strength of the entire inner member.

[0042] As described above, according to this embodiment, it is possible to provide a grommet 10 that can prevent damage to the locking portion 40 even when an excessive force is applied to the locking portion 40 in the unlocking direction.

[0043] In grommet 10, restricting protrusion 50 may be formed to extend perpendicular to the axial direction of grommet body 11.

[0044] By forming the restricting protrusion 50 in this manner, the force from the locking portion 40 can be more easily received by the restricting protrusion 50 than when the restricting protrusion is tilted, and damage to the locking portion 40 can be more reliably prevented. Furthermore, when the restricting protrusion is tilted, for example, the structure of the mold for molding the inner member can become complicated.

[0045] In the grommet 10, the regulating protrusion 50 may have a flat rib portion 52 extending radially outward from the grommet body 11 and a contact surface portion 53 having a semicircular cross section formed at the tip of the rib portion 52.

[0046] By forming a contact surface portion 53 having a semicircular cross section at the tip of the regulating protrusion portion 50 in this manner, it becomes easier to remove the inner member 30 from the mold, and the durability of the mold used to mold the inner member 30 can be increased.

[0047] In the grommet 10, a plurality of locking portions 40 may be formed on the inner main body portion 32, and the restricting protrusion portion 50 may be formed on the grommet main body 11 so as to face only one of the plurality of locking portions 40.

[0048] For example, if the restricting protrusions 50 are formed so as to correspond to all of the locking portions 40, it may become more difficult to unlock the locking portions 40. For this reason, it is sufficient to form the restricting protrusions 50 so as to correspond only to the locking portions 40 that may be pressed during operation, and in this embodiment, only one restricting protrusion 50 is formed on the grommet body 11 so as to correspond to only one of the multiple locking portions 40.

[0049] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0050] 1 Body Panel 2 through holes 10 Grommets 11 Grommet body 30 Inner member 32 Inner body 40 Lock Section 50 Regulatory protrusion 52 Rib section 53 Contact surface section W electric wire CL center axis

Claims

1. a grommet body formed of a flexible material and configured to hold an electric wire passing through a through hole in a mounting member; an inner member formed of a material having higher rigidity than the grommet body and fitted into the through hole, the inner member has an annular inner body portion and a lock portion that locks the inner body portion to the periphery of the through hole when a portion of the inner body portion is inserted into the through hole, The grommet body has a restricting protrusion formed on an outer periphery of the grommet body and coming into contact with the locking portion when the locking portion is displaced radially inward of the grommet body. Grommet.

2. The restricting protrusion is formed to extend perpendicular to the axial direction of the grommet body. The grommet of claim 1 .

3. The restricting protrusion is a flat rib portion extending radially outward from the grommet body; A contact surface portion having a semicircular cross section formed at the tip of the rib portion, The grommet of claim 1 .

4. The locking portion is formed in plurality on the inner main body portion, The restricting protrusion is formed on the grommet body so as to face only one of the plurality of locking portions. The grommet of claim 1 .

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