JP3596407B2 - Grommet, panel mounting method and mounting structure of the grommet - Google Patents

Description

[0001]
The present invention relates to a grommet which is attached to a wire harness for an automobile and is attached to a through hole of a vehicle body panel, a method of attaching the grommet to a panel, and a panel attachment structure.
[0002]
TECHNICAL FIELD OF THE INVENTION
2. Description of the Related Art Conventionally, when a wire harness is routed from an engine room of an automobile to a vehicle interior, a grommet 1 made of rubber or an elastomer is externally fitted to the wire harness W / H as shown in FIGS. The wire harness W / H to which the grommet 1 is attached passes through the through hole 3 of the vehicle body panel 2 that separates the engine room (X) and the vehicle room (Y), and the grommet 1 is attached to the periphery of the through hole 3. In addition, waterproof and dustproof properties are provided to prevent water, dust and the like from entering the vehicle compartment from the engine room side through the through holes 3.
[0003]
The grommet 1 includes a small-diameter tube portion 1a through which the wire harness W / H is inserted in a tightly-fitted state, and a large-diameter tube portion 1b continuous from one end of the small-diameter tube portion 1a in a conical tube shape. A concave portion 1c for locking the vehicle body is provided in an annular shape on the outer peripheral surface of the vehicle. The recess 1c is fitted into the through hole 3 of the vehicle body panel 2, and the grommet 1 is mounted on the vehicle body panel 2. In order to increase the locking force at the time of mounting, the portion provided with the vehicle body locking recess 1c The recess 1c is made thicker and deeper.
[0004]
Conventionally, as shown in FIG. 9, the grommet 1 is inserted from the engine room (X) through the through hole 3 into the vehicle interior (Y) from the side of the large-diameter tube portion 1 b, The entire grommet 1 is once pushed into the vehicle interior (Y) while crushing both outer peripheral portions sandwiching the large concave portion 1c. Thereafter, the wire harness W / H is pulled back from the engine room (X) side, the concave portion 1c is fitted in the through hole 3, and the grommet 1 is mounted on the vehicle body panel 2. That is, the grommet 1 is mounted on the vehicle body panel 2 by two operations of once pushing the engine from the engine room (X) into the vehicle room (Y) and then returning the grommet 1 to the engine room. The reason why the recess 1c is fitted to the vehicle body panel 2 by being pushed in once and then pulled back again because the recess 1c is pushed in from the peripheral wall 1e having a large protrusion amount is formed in the concave portion 1c between the peripheral wall 1f having a small protrusion amount. This is because the periphery of No. 3 cannot be securely fitted with a sense of moderation.
[0005]
[Problems to be solved by the invention]
Recently, with the rapid increase in the number of components mounted on an automobile, components are also arranged near both sides of the vehicle body panel 2 on which the grommet 1 is mounted. As described above, when attaching the grommet 1 to the vehicle body panel 2, first, the entire grommet 1 is pushed into the vehicle interior from the engine room side, but it is difficult to secure a space for receiving the grommet pushed in the vehicle interior. Is coming. Further, although the grommet is pushed back into the vehicle compartment and then pulled back to the engine room side, there is no longer any space on the engine room side where it is possible to carry the wire harness W / H back to the engine room side. In addition, as the space is reduced, the conventional grommet has been demanded to reduce its length.
[0006]
The present invention has been made in view of the above-described problem, and has a configuration in which a grommet can be reliably inserted and locked in a through hole of a vehicle body panel by one operation of pushing from the engine room side, and the length of the grommet itself can be shortened. It is an object to provide such a grommet.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is a grommet that is inserted and locked in a through hole of a vehicle body panel in a state where the grommet is mounted on an automobile wire harness,
A small-diameter cylindrical portion made of a molded product made of rubber or elastomer, through which the wire harness is inserted in a tightly fitted state, and a large-diameter cylindrical portion continuous from one end of the small-diameter cylindrical portion, wherein the large-diameter cylindrical portion has a through hole. To be inserted into
The large-diameter cylindrical portion is folded from the end of the through-hole insertion side to form a double cylindrical shape including an inner cylinder and an outer cylinder,
A first annular projection and a second annular projection are protruded from the outer peripheral surface of the inner cylinder, and the first annular projection and the second annular projection are inserted and locked in locking grooves formed on the inner peripheral surface of the outer cylinder. The inner cylinder and the outer cylinder are held in a folded state, and a V-shaped sealed space is provided between the first annular projection and the second annular projection, and the inner cylinder and the outer cylinder at the through-hole insertion end side. To form two sealed spaces with a closed space,
In addition, a concave portion for locking the vehicle body is formed on the outer peripheral surface of the outer cylinder at a position where the locking groove is formed, and the front side wall of the concave portion on the side where the through hole is inserted is inclined and protruded toward the rear side wall, and The grommet is characterized in that its protruding height is set low so that it can fall down into the recess.
[0008]
As described above, in the grommet of the present invention, the side wall on the through hole insertion side of the vehicle body locking recess is inclined and the height is reduced, and the locking groove is provided on the inner side of the recess to form When the side wall is pressed at the time of insertion into the through hole, the side wall is deformed inward and falls down into the concave portion so that it can pass through the through hole. After passing, the side wall returns to its original shape and protrudes, and the vehicle body panel is fitted into the recess between the other side wall, and the grommet can be attached to the panel by one operation of pushing in only. As described above, the operation force at the time of pushing is not so required, and the workability of mounting the panel can be improved. Furthermore, since a closed space is formed between the inner cylinder and the outer cylinder in the grommet, noise such as vibration noise can be reduced in the space, and sound insulation performance can be improved.
[0009]
Specifically, the grommet is attached to the through-hole with burring provided in the vehicle body panel from the engine room side to the vehicle room side by one operation of only pushing the grommet. Therefore, even when there is no space on either the engine room side or the vehicle room side, the work of attaching the grommet to the vehicle body panel can be performed without any problem.
[0010]
The annular projection is provided so as to protrude from a position close to the small-diameter cylindrical portion of the outer peripheral surface of the inner cylinder, and a concave portion for locking the vehicle body is provided on an outer cylinder formed by folding back from a tip of the inner cylinder. Since the annular projection is inserted and locked in the formed groove formed on the side and the outer cylinder is held, the concave portion for locking the vehicle body is located at a position close to the small-diameter cylindrical portion, and the overall length of the grommet in the axial direction can be shortened. it can.
[0011]
Further, the thickness of the inner cylinder and the outer cylinder surrounding the sealed space at the end of the through hole insertion side is reduced, and the slanted front side wall of the vehicle body locking recess is continuously provided to the thin portion. On the other hand, the rear wall is thick. With this configuration, the insertion force into the panel through hole can be further reduced, and the locking force after insertion into the through hole can be increased. In addition, if a lip is provided that protrudes from the tip of the thick rear wall to the side wall that is inclined, the lip comes into close contact with the vehicle body panel, and the waterproof performance can be enhanced.
[0012]
Of the annular projections , the first annular projection on the small-diameter cylindrical portion side is formed so as to be inclined toward the small-diameter cylindrical portion. The annular projection is preferably divided as described above, but may be divided into one annular projection without being divided.
[0013]
When the annular projection is divided as described above, a closed space can be formed between the annular protrusions, and the conducted noise can also be reduced in this space, and two closed spaces can be formed together with the closed space on the through hole insertion side, so that the sound insulation performance is improved. Can be enhanced. Also, during the operation of inserting and locking the grommet into the through hole of the vehicle body panel, the bottom surface of the concave portion for locking the vehicle body may be deformed so that the bottom surface of the concave portion enters the space between the first and second annular protrusions. This also makes it possible to reduce the insertion force of the grommet into the through hole. Further, since the first annular projection on the small-diameter cylindrical portion side is inclined, when a pulling force acts on the small-diameter cylindrical portion side, the first annular projection is displaced in a direction perpendicular to the axis, and the locking groove on the outer cylinder side is formed. , And the outer cylinder can be securely held in the folded state.
[0014]
A silencer member is attached to one surface of the vehicle body panel to which the grommet is attached, the surface being opposite to the grommet insertion side, and a skin is attached to the surface of the silencer member. A through hole communicating with the through hole of the vehicle body panel is formed in the silencer member, and a slightly smaller through hole is formed in the skin, and the periphery of the through hole in the skin is the tip of the large-diameter cylindrical portion of the grommet. Is pressed against the outer cylinder surrounding the closed space in a bent state, so that the sound insulation performance can be further improved.
[0015]
Usually, the outer skin is radially slit from the periphery of the through-hole so as to be in close contact with the outer peripheral surface of the grommet, but the grommet in contact with the outer periphery of the through-hole of the skin has a thin outer cylinder and an inner cylinder. Since the closed space is surrounded by the cylinder, the grommet itself has flexibility, and the grommet can be passed through the through-hole of the skin and the skin can be brought into close contact with the outer peripheral surface of the grommet without forming a slit in the skin. As described above, when the skin is not provided with the slit, the sound insulation performance can be further improved.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIGS. 1 to 5 show a first embodiment, in which a grommet 10 is made of rubber or an elastomer, and has a small-diameter tube portion 11 through which a wire harness W / H is inserted in a tightly-fitted state, and a large-diameter tube connected from one end of the small-diameter tube portion 11. The large-diameter cylindrical portion 12 has a double cylindrical structure including an inner cylinder 14 and an outer cylinder 15 as shown in FIG. As shown, the inner cylinder 14 is connected to the small-diameter tube 11, the outer tube 15 is connected to the end of the inner tube 14, and the outer tube 15 is turned back to form the inner tube 14. It has a double cylindrical shape as shown in FIG.
[0017]
The inner cylinder 14 is provided from an outer periphery of a closed wall portion 13 protruding in a radial direction from an outer periphery of one end of the small-diameter cylinder portion 11, and a first annular projection is provided at a position close to a rear end of the inner cylinder 14 on the small-diameter cylinder portion side. The projection 18 and the second annular projection 19 are provided with a V-shaped space 20 therebetween. The first annular projection 18 on the rear end side is inclined rearward with respect to the axis L. The front end face 19a of the second annular projection 19 has the base 19a inclined forward and the projection 19b is oriented perpendicular to the axis. The length from the rear end position of the first annular projection 18 to the front end position of the second annular projection 19 is L1.
[0018]
In the molded state shown in FIG. 2, the thin-walled cylinder portion 21 is extended forward from the front end of the inner cylinder 14, and the front end of the thin-walled cylinder portion 21 is folded back to form the thick vehicle body locking portion 22. Provided. The thin tube portion 21 has a shape shown in FIG. 1 in which a substantially central portion in the length direction is turned back, and a rear portion of the thin tube portion 21 becomes a front thin portion 21a of the inner tube 14 and a thin tube portion. The front side portion 21 becomes the front thin portion 21b of the outer cylinder 15, and a space 24 is formed therebetween. A rib 29 is provided on an inner surface of a continuous portion between the thin tube portion 21 and the inner tube 14.
[0019]
A locking groove 26 is provided in the inner peripheral surface of the vehicle body locking portion 22 which is continuous with the front thin portion 21b of the outer cylinder 15. The locking groove 26 is located at a position corresponding to the first annular projection 18 and the second annular projection 19 in the folded state shown in FIG. 1, and the length in the front-rear direction is L2, and L2 ≦ L1. The first annular projection 18 and the second annular projection 19 are press-fitted into the locking groove 26 to press the distal end surface 18a of the first annular projection 18 against the groove bottom surface 26a of the locking groove 26, and The front end edge 18b of the first annular projection is engaged with the rear end surface 26b of the first projection 26. The distal end surface 19c of the second annular projection 19 is pressed against the groove bottom surface 26a, and the protruding portion 19b is pressed against the front end surface 26c of the locking groove 26. As described above, by pressing the first and second annular projections 18 and 19 into the locking grooves 26, the outer cylinder 15 can be fixed in a folded state outside the inner cylinder 14.
[0020]
As described above, the space 20 between the first annular projection 18 and the second annular projection 19 is sealed by inserting the first annular projection 18 and the second annular projection 19 into the locking groove 26 and pressing them together. At the same time, the space 24 formed by folding the thin portion 21 is also sealed.
[0021]
A concave portion 28 is formed on the outer peripheral surface of the vehicle body locking portion 22 constituting the outer cylinder 15, and a front wall 30 of the concave portion which is a through hole insertion side is inclined toward the other rear wall wall 31 side, and The height of the front side wall 30 is set lower than that of the rear side wall 31 so that the front side wall 30 can fall into the recess 28. The bottom surface 28a of the concave portion 28 is formed in a substantially mountain shape so that both front and rear sides are slightly cut into the side wall side.
[0022]
As described above, the grommet 10 has the vehicle body locking portion 22 provided at a position close to the small-diameter cylindrical portion 11, and the length of the large-diameter cylindrical portion 12 is approximately ／ to し て as compared with the conventional grommet. It is as short as possible.
[0023]
As shown in FIG. 3, the grommet 10 having the above-described shape allows the wire harness W / H to penetrate in a state where the small-diameter cylindrical portion 11 is expanded using a jig (not shown), and the large-diameter cylindrical portion 12 is formed. The tape 35 is pulled out from the front end opening, and is fixed by winding a tape 35 around the tip of the small-diameter cylindrical portion 11 and the wire harness W / H. Thereafter, the grommet 10 is filled with a two-liquid sealant, and at this time, the rib 29 acts to prevent the sealant from peeling off. Note that the sealant does not have to be filled.
[0024]
When wiring the wire harness W / H to which the grommet 10 is attached to a vehicle, as shown in FIGS. 4 (A), 4 (B), and 4 (C), the vehicle room (X) passes through the through hole 3 of the vehicle body panel 2 and the vehicle compartment. (Y). A burring 3 a protrudes toward the engine room (X) from the periphery of the through hole 3. A silencer 40 is attached to the indoor side of the vehicle body panel 2, and a through hole 41 having substantially the same diameter as the through hole 3 is formed in the silencer 40. A skin 42 made of a resin sheet or the like is further attached to the surface of the silencer 40, and the skin 42 is provided with a through hole 43 that is slightly smaller than the through hole 41. Conventionally, a slit is provided radially on the periphery of the through hole 43, but the skin 42 on which the grommet 10 of the present invention is mounted is not provided with a slit.
[0025]
The grommet 10 attached to the wire harness W / H is pushed into the through hole 3 of the vehicle body panel from the large-diameter cylindrical portion front end F composed of the thin portions 21a and 21b surrounding the closed space 24 as shown in the drawing. Go. During this insertion, the diameter D1 of the front end F is smaller than the diameter D2 of the through hole 3 of the vehicle body panel 2 and the through hole 41 of the silencer 40, so that the front end F can be easily inserted. Since the diameter D3 of the through hole 43 of the skin 42 of the silencer 40 is set smaller than the front end diameter D1 of the grommet 10, the periphery of the through hole of the skin bends forward to the outer peripheral surface of the thin portion 21b of the outer cylinder of the grommet 10. While sticking. At this time, since the inside of the thin portion 21b is the space 24, the thin portion 21b can also be easily bent. Can be brought into close contact.
[0026]
On the other hand, when the burring 3a projecting from the through hole 3 toward the engine room (X) reaches the inclined front wall 30 of the vehicle body locking portion 22, the burring 3a presses the front wall 30 inward. When the grommet 10 is pushed in, the front wall 30 is pushed down by the burring 3 a and falls into the rear recess 28 as shown in FIG. 4B. At this time, the bottom surface 28 a of the concave portion 28 is deformed so as to cut into the space 20 between the first annular projection 18 and the second annular projection 19, thereby promoting the reduction of the diameter of the front side wall 30. In this manner, the burring 3a can get over the front wall 30 with a low operation force, and the front wall 30 can be passed through the through hole 3 and the burring 3a without requiring a large operation force.
[0027]
When the front side wall 30 comes off from the tip of the burring 3a, the front side wall 30 returns to its original state and projects outward. It is in a state of being fitted in between, and is locked in the concave portion 28. At this time, since the front wall 30 is inclined toward the rear wall 31, the front wall 30 is in close contact with the indoor surface side of the panel 2.
[0028]
As described above, the grommet 10 attached to the wire harness W / H can be locked by passing the grommet 10 through the through hole 3 by one operation of simply pushing the grommet 10 from the engine room side. Therefore, the grommet mounting operation is simplified as compared with the conventional push-pull operation, and the grommet can be mounted without any problem even if there is no space in the vehicle interior and the engine room.
[0029]
Further, since the grommet 10 has the two closed spaces 20 and 24, noise that enters from the engine room side to the room side is attenuated in the spaces 20 and 24, and the sound insulation performance can be improved. Further, since no slit is formed in the periphery of the through hole of the skin 42 of the silencer 40, sound can be prevented from leaking through the slit, and the sound insulation performance can be further improved.
[0030]
With the grommet 10 attached to the vehicle body panel 2, when the wire harness W / H is pulled toward the engine room (X) or when an external force acts in the pulling direction, as shown in FIG. The annular projection 18 is in a direction perpendicular to the axis with respect to the grommet 10. Therefore, since the locking and holding force between the inner cylinder 14 and the outer cylinder 15 is further increased, the waterproof function can be maintained, and the locking groove 26 and the annular projections 18 and 19 can be prevented from being separated from the vehicle body panel 2. The grommet 10 can be reliably prevented from coming off.
[0031]
Further, as shown in FIG. 5B, the grommet 10 may be forced to be bent by about 30 degrees in relation to the other parts on the engine room side and the grommet 10 must be inserted into the through hole 3. In this case, on the upper side of the drawing, the second annular projection 19 abuts and locks on the front end surface 26c of the locking groove 26, and on the lower side, the first annular projection 18 abuts on the rear side surface 26b of the locking groove 26. Locked. Therefore, even if the grommet is inclined, waterproof performance can be ensured, and the annular projections 18 and 19 do not come off from the locking groove 26.
[0032]
FIG. 6 shows a modification of the first embodiment, with the following changes.
{Circle around (1)} The front end surface 26c 'of the locking groove 26 is a tapered surface inclined backward. The tapered surface prevents the locking projection 19 'from moving when pushed.
{Circle around (2)} The front end face 19b 'of the locking projection 19' is continued in a large arc shape without any step. The strength of the locking projections 19 'is maintained by eliminating the dents continuously.
[0033]
7A and 7B show a reference embodiment. In the grommet 10 'of the reference embodiment, the annular projection provided on the inner cylinder 14 is formed from one annular projection 50 without being divided. Further, a lip 51 is provided on the rear side wall 31 of the vehicle body engaging concave portion 28 of the outer cylinder 15 to protrude forward. The tip of the lip 51 protrudes further forward than the front side wall 30 so that the lip 51 is pressed against the surface of the vehicle body panel on the engine room side with the grommet 10 ′ attached to the vehicle body panel 2. The other configuration is the same as that of the first embodiment.
[0034]
【The invention's effect】
As is apparent from the above description, in the grommet according to the present invention, the height of the front side wall of the through hole insertion side of the vehicle body locking recess is reduced and inclined toward the rear side wall. When pressed into the through hole, the front side wall is easily reduced in diameter and passes through the through hole, thereby facilitating the panel mounting operation of the grommet. As described above, since the grommet can be locked in the through hole of the vehicle body panel by only one operation of pushing the grommet, the grommet can be smoothly mounted even when there is no space near the grommet mounting position. Further, since it is only necessary to push the grommet, the workability of mounting the grommet can be improved.
[0035]
In addition, since a closed space surrounded by a thin portion is provided at the end of the through hole insertion side, sound insulation performance can be improved. In particular, if a closed space is provided between the first annular protrusion and the second annular protrusion, two closed spaces can be formed inside the grommet, so that a grommet having excellent sound insulation performance can be obtained.
[0036]
Furthermore, since the large-diameter cylindrical portion is formed by folding back, and the vehicle body locking portion is disposed at a position close to the small-diameter cylindrical portion, the total length of the grommet can be shortened. Therefore, the grommet arrangement space can be reduced. In addition, there are various advantages such as an advantage that waterproof performance can be ensured even when the grommet is attached to the vehicle body panel slightly obliquely.
[Brief description of the drawings]
FIG. 1 is a sectional view of a grommet according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the grommet during molding.
FIG. 3 is a sectional view showing a state where a wire harness is attached to the grommet.
FIGS. 4A, 4B, and 4C are views showing a step of locking a grommet attached to the wire harness through a through hole of a vehicle body panel.
5A is a cross-sectional view when the grommet is pulled toward the engine room, and FIG. 5B is a cross-sectional view when the grommet is slightly bent and attached.
FIG. 6 is a cross-sectional view showing a modification of the first embodiment.
7A and 7B show a reference embodiment, wherein FIG. 7A is a cross-sectional view of the grommet of the second embodiment, and FIG.
FIG. 8 is a sectional view showing a conventional grommet.
FIGS. 9A to 9C are views showing a process of inserting and locking a conventional grommet into a through hole of a vehicle body panel.
[Explanation of symbols]
2 Body panel 3 Through-hole 3a Burring 10 Grommet 11 Small-diameter cylindrical part 12 Large-diameter cylindrical part 14 Inner cylinder 15 Outer cylinder 18 First annular projection 19 Second annular projection 20 Sealed space 21 (21a, 21b) Thin part 22 Car body locking Part 24 closed space 26 locking groove 28 concave part 30 inclined front side wall 31 rear side wall 40 silencer 42 skin W / H wire harness

Claims (6)

A grommet that is inserted and locked into a through hole of a vehicle body panel in a state where the grommet is mounted on an automobile wire harness,
A small-diameter cylindrical portion made of a molded product of rubber or elastomer, through which the wire harness is inserted in a tightly fitted state, and a large-diameter cylindrical portion continuous from one end of the small-diameter cylindrical portion, wherein the through-hole is formed from the large-diameter cylindrical portion. To be inserted into
The large-diameter cylindrical portion is folded from the end of the through-hole insertion side to form a double cylindrical shape including an inner cylinder and an outer cylinder,
A first annular projection and a second annular projection are protruded from the outer peripheral surface of the inner cylinder, and the first annular projection and the second annular projection are inserted and locked in locking grooves formed on the inner peripheral surface of the outer cylinder. The inner cylinder and the outer cylinder are held in a folded state, and a V-shaped sealed space is provided between the first annular projection and the second annular projection, and the inner cylinder and the outer cylinder on the through-hole insertion end side. To form two sealed spaces with a closed space,
In addition, a concave portion for locking the vehicle body is formed on the outer peripheral surface of the outer cylinder at a position where the locking groove is formed, and the front side wall of the concave portion on the side where the through hole is inserted is inclined and protruded toward the rear side wall. A grommet characterized in that its protruding height is set low so that it can fall down into a recess. The thickness of the inner cylinder and the outer cylinder surrounding the closed space at the end of the through hole insertion side is reduced, and the inclined side wall of the vehicle body locking concave portion is continuously provided to the thin portion, while The grommet according to claim 1, wherein the side wall is thick. Grommet according to claim 1 or claim 2 are formed by inclining the first annular protrusion of the small-diameter cylindrical portion side to the small diameter cylinder portion of the annular projection. The annular projection is provided so as to protrude from a position close to the small-diameter tube portion side of the outer peripheral surface of the inner cylinder, a concave portion for engaging the vehicle body of the outer tube is provided at a position close to the small-diameter tube portion, and the entire length of the grommet in the axial direction is provided. The grommet according to any one of claims 1 to 3, wherein is set shorter. The grommet according to any one of claims 1 to 4, which is externally fitted and fixed to the wire harness, is pushed into the through-hole with burring of the vehicle body panel from the side of the large-diameter cylindrical portion to lock the vehicle body. The inclined side wall of the concave portion is passed through the through hole while being tilted into the concave portion by the burring. A grommet installation method that attaches the grommet to the vehicle body panel with only one push-in operation. A structure in which a grommet is attached to a vehicle body panel by the method according to claim 5,
A silencer member is attached to one surface of the vehicle body panel opposite to the grommet insertion side, and a skin is adhered to the surface of the silencer member, and the silencer member has a through hole communicating with a through hole of the vehicle body panel. Is formed and a slightly smaller through hole is formed in the epidermis,
A grommet panel mounting structure in which a peripheral edge of a through hole of the skin is pressed against an outer cylinder surrounding a sealed space at a tip end of a large-diameter cylindrical portion of the grommet.

Images