A STRUCTURE OF A WEATHERSTRIP FOR AN AUTOMOTIVE VEHICLE

Abstract: A structure of a weatherstrip applicable to a door portion or a trunk lid and a vehicle body (5) is disclosed in which one of grasping lips (17) impinged on a flange portion (6) of an opening edge of the vehicle body (5) so as to grasp the flange portion (6) and sub-lip (20) integrally formed at an end edge of a weatherstrip main body (11) so as to extend toward the outside portion of the vehicle body (5) are seesawed with a linkage portion (19) between the grasping lip (17) and sub-lip (20) as a fulcrum. When the weatherstrip main body (11) is inserted onto the flange portion (6), a tip portion (17a) of the corresponding grasping lip (17) is abutted with the outside surface of the flange portion (6) and is easily pivoted toward the outside of the flange portion (6) with the linkage portion (19) as the fulcrum. When the tip portion (17a) of the grasping lip (17) is pivoted toward the outside portion of the flange portion (6), its reaction force causes the sub-lip (20) to pivot toward the internal direction so that its tip portion (17a) is impinged on the end surface of the vehicle body (5).

Description: The present invention generally relates to an improvement in a structure of a weatherstrip for sealing a space between, e.g., an opening edge of a vehicle body and a trunk lid thereof. JP-U-179 114/86 published on November 8, 1986, on which the preamble of claim 1 is based, exemplifies a previously proposed structure of the weatherstrip. In the above-identified Japanese Utility Model Application Publication, a hollow sponge rubber (rubber foam) sealing portion is disposed on an upper part of a welt, as a main body of the weatherstrip, made of a solid rubber having a substantially U-shaped cross section. In addition, a plurality of lips extend toward an inside space of the welt from both opposing surfaces of side parts of the welt. Furthermore, a sub-lip extending externally from one of the lips is disposed on a base end of one of the side parts of the welt. The sub-lip faces toward an outside of a vehicle body. The sub-lip serves to prevent liquid such as water from invading into the inside of the vehicle body via a flange portion to be described below. When the above-described welt is inserted into an upwardly-extending flange portion on an opening edge of the vehicle body, each lip impinges so as to grasp the flange portion to prevent a rolling of the welt and the sub-lip is brought in contact with an end outside surface of the vehicle body so as to prevent water or dirt from invading into the inside of the vehicle body. In the structure of the weatherstrip described above, the sub-lip extends continously from the opposing lower lip and the end of the side part placed at an external side of the vehicle body is relatively thick as compared with the lower lip and welt so that a high rigidity of a base end of the welt is ensured. Therefore, since there is no direct relationship between the lower lip and sub-lip , it is difficult and troublesome to insert the welt into the flange portion because of the high rigidity of the base end placed between the lower lip and the sub-lip. In addition, the sub-lip does not easily contact the end surface of the vehicle body under pressure. It is an object of the present invention to provide a structure of a weatherstrip applicable to a flange portion placed on an opening edge of a vehicle body which is capable of easily inserting a welt of the weatherstrip into the flange portion of the vehicle body and whose sub-lip is easily contacted with an end surface of the vehicle body. The invention provides a structure of a weatherstrip, comprising: (a) a main body having a cross sectional structure such as to accommodate both side surfaces of a projecting member with a space defined by the main body and both side surfaces of the projecting member; (b) at least one first lip extending toward a first side surface of such a projecting member from an inside surface of the main body so that a tip portion of the first lip is pressed against the first side surface of the projecting member when the main body rests on the projecting member; and (c) at least one second lip extending toward a second side surface of the projecting member from one free end of the inside surface of the main body; characterised in that it comprises (d) a third lip extending toward a third surface of a part of the projecting member, the said third surface being substantially perpendicular to the second side surface, from the free end of the inside surface of the main body linked with the second lip, and in that both second lip and third lip are a seesaw configuration with the free end of the inside surface of the main body as a fulcrum. Further developments in line with claim 1 are referred to in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross sectional view of a weatherstrip structure in a first preferred embodiment according to the present invention. Fig. 2 is a cross sectional view of the weatherstrip structure for explaining an operation of the first preferred embodiment shown in Fig. 1. Fig. 3 is a cross sectional view of the weatherstrip structure in a second preferred embodiment according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will hereinafter be made to the drawings in order to facilitate understanding of the present invention. Figs. 1 and 2 show a first preferred embodiment of the weatherstrip structure according to the present invention. In the first preferred embodiment, the weatherstrip structure is applied to a space between a vehicle body generally denoted by 5 and a rear door portion. A welt denoted by 11 is a main body of the weatherstrip made of a solid rubber and has a substantially letter U-shaped cross section. A hollow sealing portion 12 is disposed on an upper part 13 of the welt 11 and is to be brought in close contact with a peripheral edge of the rear door portion. The sealing portion 12 is made of a sponge rubber (rubber foam). A plurality of grasping lips 16, 17 are disposed so as to extend internally from both side parts 14, 15 of the welt 11. A seal lip 18 made of the sponge rubber is provided on an outer surface of a lower end 14a of one side part 14 of the welt 11 located on the outside of the vehicle body. The seal lip 18 is contacted with an end surface 7 of an opening of the vehicle body 5 so as to prevent an inclination of the welt 11. In addition, a thin linkage portion 19 is integrally extended along an elongated direction of a lower edge of the lower end 14a. The grasping lip 17 is formed on an inside of a lower peripheral edge of the linkage portion 19 and a sub-lip 20 is integrally extended from the outside of the linkage portion 19. It is noted that both lips 17, 20 are formed in a seesaw configuration such as to pivot with the linkage portion 19 as a fulcrum. Furthermore, the sub-lip 20 has a tip portion 20a formed of the sponge rubber and has a projection portion 20b at an upper part thereof which is contacted with an inner side projecting surface of the seal lip 18. The projection portion 20b is extended along the elongated direction of the seal lip 20. It is noted that as viewed from Figs. 1 and 2 a position of the linkage portion 19 is slightly higher than an opposing base end of the side part 15 of the welt 11 and a thin iron plate is extended in the welt 11 in a slightly asymmetrical state. Next, an operation of the first preferred embodiment will be described below. When the welt 11 is pressed and inserted in a direction denoted by an arrow with an arrow toward a flange portion 6 located on the opening edge of the vehicle body 5, the tip portion 17a of the grasping lip 17 is abutted with the outside surface 6a of the flange portion 6 and is easily pivoted and inclined toward an outer direction denoted by a with an arrow (refer to a dot-and-dash line). Hence, an insertability of the welt 11 into the flange portion 6 becomes favorable and thereby an efficiency of assembly operation is improved. On the other hand, with the tip portion 17a of the grasping lip 17 tilted toward the outside of the flange portion 6, its reaction force causes the sub-lip 20 to pivot and tilt in the inside direction denoted by b with an arrow (refer to the dot-and-dash line). Upon the end of the insertion of the welt 11, the tip portion 20a is brought in close contact with the opening end surface 7 under pressure. Hence, a sealing performance between the inside and outside of the vehicle body is improved by means of the sub-lip 20 and therefore a water-tight structure can be assured. in addition, since a pressure is provided for the grasping lip 17 due to the internal pivot of the grasping lip 17 caused by a reaction of the high pressure of the seal lip 20 applied to the opening end surface 7, a grasping force to the flange portion 6 is improved. Since at this time the seal lip 18 is also abutted with the opening end surface 7 of the vehicle body, the seal lip 18 and the sub-lip 20 provide a double sealing characteristic so that the sealing performance will remarkably be improved. When the welt 11 is attached to, e.g., an upper side of the opening edge of the vehicle body and a force is imposed in a direction (direction B with an arrow mark) falling down from the flange portion 6 due to its own weight, as shown in Fig. 2, the grasping lip 16 pivots toward the inner direction (direction c with an arrow mark) due to the friction against the outside surface 6a of the flange portion 6. Therefore, the sub-lip 20 pivots upward (direction d with an arrow mark). At this time, a reaction force is generated on the projecting portion 20b which is impinged on the inner side projecting surface of the seal lip 18. Hence, the pressing force of the grasping lip 17 against the outside surface 6a of the flange portion 6 becomes remarkably increased so that a retentive force of the grasping lip 17 is reinforced. Consequently, the falling down of the welt 11 can positively be prevented. Fig. 3 shows a second preferred embodiment of the weatherstrip structure. In the second preferred embodiment, the lower end portion 14a of one side part 14 located at the inner side of the vehicle is extended downward. Therefore, a mounting position of the grasping lip 17 installed on the lower end portion 14a via the linkage portion 19 is placed at a lower position than the mounting portion of the grasping lip 16 installed at the lower end of the side part 15. The opposing positions of both tip portions 16a, 17a are offset in the upper and lower directions. Hence, in a case when the welt 11 is pressed and inserted into the flange portion 6 in the same way as in the first preferred embodiment, the tip portion 6b of the flange portion 6 is impinged on the tip portion 17a of the grasping lip 17 and subsequently impinged on the tip portion 16a of the grasping lip 16 at the opposite side to the tip portion of the grasping lip 17. Consequently, the insertability of the welt 11 into the flange portion 6 becomes remarkably increased together with the seesaw configuration described in the first preferred embodiment. Especially, the insertability becomes increased when the welt 11 is once inserted into the flange portion 6, thereafter, is pulled out of the flange portion 6, and then again inserted thereinto. That is to say, since the tip portions 16a, 17a of both grasping lips 16, 17 are offset, both tip portions 16a, 17a are not deformed and abutted with each other interfering together with the flange portion but the appropriate tilting postures toward the inside of the flange portion in the same way as the original state are individually maintained. Conseqently, the first insertability and second insertability become favorable and the efficiency of assembly operation is more remarkably increased. Although in the second preferred embodiment the side part 14 at the vehicle body inside is extended in the downward direction, it is possible to shorten the length of the one side part 15 at the vehicle body outside with the relative positional relationship to the length of the flange portion 6 taken into consideration. The other construction is the same as that in the first preferred embodiment. It is noted that since the tip portion 16b of the upper grasping lip 16 of the side part 14 at the vehicle inside portion is formed of the sponge rubber, the grasping lip 16 against the outside surface 6a of the flange 6 is more tightly sealed. Although in both preferred embodiment the weatherstrip structure is applied to the space between the vehicle door and rear door portion, the weatherstrip structure according to the present invention is also applicable to a space between the vehicle body and another door portion of the vehicle or a trunk portion. As described hereinabove, since the weatherstrip structure according to the present invention has the seesaw configuration at the grasping lip and sub-lip via the linkage portion, the insertability thereof is increased due to the easy pivoting of the grasping lip at the time of the insertion of the welt into the flange portion. The pressing force of the sub-lip against the end surface of the vehicle body becomes large since the pivoting force is applied to the sub-lip in the same direction as the pivoting force of the grasping lip at the time of end of the insertion. Therefore, the high sealing performance and water tightness can be achieved.

Claims: A structure of a weatherstrip, comprising: a) a main body (11) having a cross sectional structure such as to accommodate both side surfaces of a projecting member (5) with a space defined by the main body and both side surfaces of the projecting member: b) at least one first lip (16) extending toward a first side surface of such a projecting member from an inside surface of the main body so that a tip portion of the first lip is pressed against the first side surface of the projecting member when the main body rests on the projecting member; and c) at least one second lip (16, 17) extending toward a second side surface of the projecting member from one free end of the inside surface of the main body; characterised in that the structure of the weatherstrip comprises: d) a third lip (20) extending toward a third surface (7) of a part of the said projecting member (5), said third surface (7) being substantially perpendicular to said second side surface (6a), from the free end of the inside surface of the main body linked with said second lip (17), and in that both second lip (17) and third lip (20) are in a seesaw configuration with the free end of the inside surface of the main body as a fulcrum. A structure as set forth in claim 1, wherein the main body and the first (16), second (16, 17), and third (20) lips are integrally formed. A structure as set forth in claim 1 or claim 2, wherein the main body (11) comprises a solid rubber member. A structure as set forth in claim 2 and claim 3, wherein a linkage portion (19) between the second lip (16, 17) and the third (20) lip is relatively thin. A structure as set forth in claim 2 and claim 3, wherein a linkage portion (19) between the second (16, 17) lip and the third lip (20) has the substantially same thickness as the second lip (16, 17) and/or the third lip (20). A structure as set forth in any one of claims 1 to 5, wherein an edge of the free end of the inside surface of the main body (11) is relatively thin. A structure as set forth in any one of claims 1 to 6, wherein the main body has a substantially U-shaped cross-section. A structure as set forth in any one of claims 1 to 7, which comprises a fourth lip (16, 16b) extending toward the second side surface of the projecting member from the inside surface of the main body (11). A structure as set forth in claim 8, wherein all free ends of the first (16), second (17), and fourth (16, 16b) lips are arranged to press against the first and second surfaces of the projecting member so as to face toward a tip end of the projecting member. A structure as set forth in claim 8 or claim 9, wherein a tip portion (16b) of the fourth lip is made of a sponge rubber. A structure as set forth in any one of claims 1 to 10, which comprises a sponge rubber member (18) extending from an opposite surface of the main body (11) toward the third surface (7) of the projecting member. A structure as set forth in claim 11, wherein an intermediate surface of the sponge rubber member (18) projects toward an opening surface (7) of the third lip (20) which projects toward the intermediate surface of the sponge member (18). A structure as set forth in any one of claims 1 to 12, wherein a free end of the third lip (20) is made of a sponge rubber. A structure as set forth in any one of claims 1 to 13, wherein a relatively thin iron plate extends within the main body (11) for reinforcing the main body (11). A structure as set forth in any one of claims 1 to 14, which comprises a hollow sponge member (18) extending from an outer surface of the main body (11). A structure as set forth in any one of claims 1 to 15, wherein the projecting member is a flange portion (6) of a vehicle body and the third surface (7) of the projecting member faces toward an outside of the vehicle body. A structure as set forth in claim 16, wherein a continuous space is provided between the inner surface of the main body (11) and the tip of the flange portion (6). A structure as set forth in claim 16 or claim 17, wherein the flange portion (6) is substantially orthogonal to the outside surface of the vehicle body. A structure as set forth in any one of claims 16 to 18 applicable to a space between a trunk lid and an associated vehicle body (5).

Inventors: SAKAMAKI, YUUJI, SAKUMA, HIROSHI
Applicants: KINUGAWA RUBBER IND. CO., LTD.
Application year: 1988
Main classification: B60R13
IPC codes: B60J10, B60R13