Patent Application
20190218853
The present invention relates to a seal member used in, for example, the door of a vehicle or building, to the manufacturing method of the seal member, and to a vehicle door or building door that includes the seal member.
A door that is provided in a building or a vehicle such as an automobile is of a configuration in which a seal member (packing) for raising sealability is attached to the outer periphery of the door body that is made of a rigid body such as metal. The seal member preferably prevents or reduces the infiltration of water or dirt, and moreover, possesses high sound-insulating performance for maintaining a quiet interior as well as resistance to heat and weather. A normal seal member is attached to the outer periphery of the door body and exhibits excellent sealing performance when in a compressed state interposed between the door body and the door frame. Accordingly, the seal member is usually in the form of a hollow tube composed of an elastomer that can be readily elastically deformed such that the seal member is interposed and compressed between the door body and the door frame.
Patent Document 1 discloses a configuration in which a hard core and a soft filler are inserted into the interior of a hollow tube (hollow seal part) that prevents excessive deformation. In the configuration disclosed in Patent Document 2, a columnar cushion part that is composed of a highly-foamed sponge material made from rubber or synthetic resin is provided in the interior of a hollow tube (hollow seal part). The interior of the tube is not completely filled by the columnar cushion part, two air holding spaces (sealed space parts) remaining inside the tube. In the configuration disclosed in Patent Document 3, a rubber or synthetic resin highly-foamed sponge material is provided in the interior of a hollow tube (hollow seal part). The interior of the tube is not completely filled by the highly-foamed sponge material, an air-holding space (air layer) remaining inside the tube. Further, in the configuration disclosed in Patent Document 4, a waterproof tube filled with a porous sound-absorbing material is inserted into the interior of a hollow tube (hollow seal part). These hollow tubes can be formed by the material described in, for example, Patent Document 5. Patent Document 6 discloses a manufacturing method of an open-cell foamed body.
Patent Document 1: JP H9-286239A
Patent Document 2: JP 2003-81026A
Patent Document 3: JP 2001-206166A
Patent Document 4: JP H2-75316U
Patent Document 5: WO2009/072503A
Patent Document 6: JP 2013-234289A
Recent years have seen the proliferation of automobiles that take electric motors as their drive source (electric vehicles or hybrid vehicles). An electric motor produces noise of a higher frequency (approximately 2000 Hz-approximately 16,000 Hz) than a gasoline engine. This high-frequency noise is extremely unpleasant, and an improvement of the sound insulation performance over the prior art is therefore sought for the seal member of the door of a vehicle equipped with an electric motor. With the changes in the environment, there is a further trend for the greatest possible sound insulation performance in the doors of buildings as well.
When the interior of the hollow tube is completely filled with, for example, a resin as in the configuration described in Patent Document 1, the damping of vibration is limited and the sound insulation performance is poor. Weather stripping of a configuration in which a highly-foamed sponge is arranged in the interior of a hollow tube is disclosed in Patent Documents 2 and 3. Still further, the attributes of not only soundproof but also waterproof capabilities are disclosed as capabilities of the weather strip. This weather strip exhibits the desired capabilities by being deformed, and the provision of air passage holes for facilitating deformation can therefore be described as a well-known feature among those of skill in the art. As a result, there is no motive to select and use, among highly-foamed materials, a highly water-absorbent material, in particular, as a provision against the infiltration of water. In addition, in the inventions described in Patent Documents 2 and 3, the hollow seal part and highly-foamed sponge are formed by extrusion molding as a single unit and are basically composed of the same type of material (rubber or synthetic resin highly-foamed sponge). In other words, it is not assumed that the material that is provided in the interior of a hollow tube is to be freely selected from among various materials without regard to the material of the tube for the object of improving sound insulation performance.
The configuration of Patent Document 4 is of a two-layered tube construction in which a sound-absorbing material such as a glass wool is inserted inside a waterproof tube, which is then inserted into the interior of a hollow tube (hollow seal part). Accordingly, an insert member must be manufactured by filling the interior of a waterproof tube having thin film thickness with a sound-absorbent material such as glass wool, and this insert member must then be inserted into the hollow tube, with the result that the manufacturing steps are numerous and complex. In addition, the thickness of the film of the waterproof tube must be made thin so as not to detract from the sound-absorbing properties of the sound-absorbing material, and the thinner the waterproof tube, the more complex the steps for packing the sound-absorbing material. Accordingly, the invention described in Patent Document 4 encounters problems in both maintaining the sound-absorbing effect realized by the sound-absorbing material and easing the complexity of the manufacturing steps.
Furthermore, no disclosure is made in any of Patent Documents 1-4 regarding the frequency selectivity of the sound insulation performance.
Further, in addition to the resistance to heat, resistance to weather and sound insulation performance, a reduction of weight is yet another desirable attribute for a door for a vehicle or a door for a building that is to be considered as the use of a seal member. In a door for a vehicle, the reduction of weight of the entire vehicle is a crucial factor for the improvement of running performance or operability or for lower fuel consumption, and the weight of seal member cannot be ignored. In the case of a building door, moreover, a reduction of weight is to be desired to facilitate the job of installing the door and, further, the job of transporting the door to the installation site, particularly when installation is to be in a high-rise building. In Patent Documents 1-4, however, absolutely no consideration is given to the increase of weight caused by inserted members (hard core and soft filler, columnar cushion part, highly-foamed sponge material, sound-absorbing material and waterproof tube) for raising sound insulation performance.
It is therefore an object of the present invention to provide a seal member, a manufacturing method of the seal member, and a door for a building or a door for a vehicle that allow an increase of resistance to heat, resistance to weather and sound insulation performance, and further, that both facilitate manufacture and enable prevention or reduction of increase of weight.
The elastically deformable seal member of the present invention has a hollow tube and a porous body that is inserted inside the tube, wherein: the interior of the tube is not completely filled by the porous body, and air-holding space is provided between a portion of the inner wall of the tube and a portion of the outer surface of the porous body; the porous body is composed of a material having a water absorption coefficient of at least 10% and no greater than 3000% in an uncompressed state; and the porous body is arranged such that the volume of the porous body occupies at least 2.5% of the internal volume of the tube. In addition, the porous body is composed of a material having a bulk density of at least 10 kg/m3 and no greater than 150 kg/m3 in an uncompressed state. In addition, the porous body is composed of a material for which compression stress is no greater than 1 N/cm2 for compression in which the dimension in the direction of compression is reduced by 25%. Further, the porous body is composed of a material for which compression stress is no greater than 2.5 N/cm2 for compression in which the dimension in the direction of compression is reduced by 50%.
Further, according to one aspect of the present invention, the porous body is arranged such that the volume of the porous body is no greater than 89% of the internal volume of the tube.
Another elastically deformable seal member of the present invention has a hollow tube and a porous body that is inserted in the interior of the tube, wherein the interior of the tube is not completely filled by the porous body, an air-holding space is provided between a portion of the inner wall of the tube and a portion of the outer surface of the porous body, and the porous body is composed of a material that contains a nonwoven fabric or is composed of a material that contains polyurethane foam.
The manufacturing method of an elastically deformable seal member of the present invention, the elastically deformable seal member having a hollow tube of a configuration in which a plurality of hollow tube members are joined by way of a joint and a porous body that is inserted in the interior of the tube, has steps of: inserting the porous body into the interior of at least one tube members before joining; after the step of inserting the porous body into the interior of at least one tube members, attaching each of the tube members to the two end portions of a rod-shaped core for joint formation; forming a joint composed of a vulcanized rubber layer or a resin layer that can be elastically deformed on the outer circumference of the core to which the tube members are attached at its two end portions; and after the step of forming the joint that is composed of a vulcanized rubber layer or a resin layer that can be elastically deformed on the outer circumference of the core, removing the core from a slit part of the joint.
In another seal member of the present invention, a seal member that is elastically deformable and that has a hollow tube of a configuration in which a plurality of hollow tube members are joined by way of a joint and a porous body that is inserted into the interior of the tube, wherein the porous body is bonded to the inner surface of the tube member into which the porous body has been inserted.
According to the present invention, a seal member, a vehicle door and a building door can be realized that increase heat resistance, weather resistance and sound insulation performance, and further, that can both facilitate manufacturing and prevent or reduce increase of weight.
Embodiments of the present invention are next described.
Seal member 1 of the present invention is chiefly used in vehicle door 2 shown in
As shown in
Water absorption coefficient [%]={(W2−W1)/W1}×100
W1: Weight (g) of the test piece before dipping
W2: Weight (g) of the test piece after dipping
As shown in
Air-holding space 8 is maintained without being eliminated even in the compressed state when interposed between door body 2a and door frame 4 during the use of seal member 1. The cross section of compressed porous body 7 of a section that is orthogonal to the longitudinal direction of tube 6 in the state of use of seal member 1 (for example, a 30%-compressed state, i.e., a compressed state in which the dimension in the direction of compression is decreased by 30%) is at least 5% and no greater than 90% of the cross section of the hollow portion (including the portion occupied by porous body 7 inside tube 6) that is the portion enclosed by the inner wall of tube 6. In other words, the area of air-holding space 8 in the state in which seal member 1 is used is at least 10% and no greater than 95% of the cross section of the portion that is enclosed by the inner wall of tube 6. When porous body 7 is inserted along the entire length of tube 6, the volume occupancy of porous body 7 inside the hollow portion of tube 6 is at least 5% and not greater than 90% if the ratio of the cross section of porous body 7 with respect to the cross section of the hollow portion of tube 6 is at least 5% and no greater than 90%. However, porous body 7 need not necessarily be inserted along the entire length of tube 6, and the effect of improving sound insulation properties is obtained even when porous body 7 is arranged in only a portion of the longitudinal direction of the hollow portion of tube 6. The volume occupancy and sound insulation performance for such cases will be described hereinbelow.
Examples of the material of porous body 7 include materials such as foamed rubber, nonwoven fabric, and polyurethane foam. Regardless of which material is used, the material that forms porous body 7 preferably has a water absorption coefficient of at least 10% and no greater than 3000% in the uncompressed state. The maximum value of the water absorption coefficient is more preferably 2800%, still more preferably 2500%, even more preferably 2000%, and particularly preferably 1600%. On the other hand, the minimum value of the water absorption coefficient is more preferably 12%, and still more preferably 13%. The water absorption coefficient of the material that makes up porous body 7 is measured by the same method as for the elastomer material that makes up tube 6 described hereinabove. At this time, by using test pieces that are formed such that the surface area of each is 4000 mm2, the water absorption coefficient is measured under substantially the same conditions even when the shape of each test piece differs. In addition, the bulk density of the material that makes up porous body 7 in the uncompressed state is at least 10 kg/m3 and no greater than 150 kg/m3. Still further, the material that makes up porous body 7 has compression stress of no greater than 1 N/cm2 for compression for which the dimension in the direction of compression decreases by 25% (25% compression stress) and compression stress of no greater than 2.5 N/cm2 for compression for which the dimension in the direction of compression decreases by 50% (50% compression stress).
The sound insulation performance of seal member 1 can be measured by the acoustic characteristics measurement system shown in, for example,
Amount of sound insulation [dB]=SPL0 [dB]−SPL1 [dB]
In
Here, the sound insulation performance of seal member 1 can be represented by an average decibel value of the amount of sound insulation of a specific frequency range (for example, 4000 Hz-10000 Hz). The amount of improvement of sound insulation realized by the present invention can be shown by calculating the average decibel value of the amount of sound insulation of a specific frequency range of seal member 1 of the present invention and comparing with the average decibel value of the amount of sound insulation for the same frequency range of the seal member of the prior art having a configuration in which nothing is inserted in the interior of hollow tube 6. The sound insulation effect of each seal member is determined in four levels as next shown on the basis of the amount of improvement of sound insulation with respect to a seal member that is taken as a reference and is represented in Tables 1-3 that are to be described. ⊙: 6 dB or more; ◯: 2 dB or more and less than 6 dB; Δ: 1 dB or more and less than 2 dB; x: less than 1 dB
The results of measuring the sound insulation effects of each of seal member 1 of the present invention that uses porous body 7 composed of various materials, the seal member of the prior-art example, and comparative examples are described below. In all of the following examples, tube 6 that was manufactured in conformity with Patent Document 5 is composed of an ethylene α-olefin nonconjugated polyene copolymer, whose water absorption coefficient is 0.49% in an uncompressed state and whose specific gravity is 0.62 in an uncompressed state. The tube has a shape in which mounting members are provided on a cylinder having an outside diameter of 19-22 mm and an inside diameter of 15-16 mm in the uncompressed state, and the entire length of the tube is 840 mm. At the time of measurement, the seal member is held in a 30% compressed state as mentioned above and the acoustic characteristics measurement system shown in, for example,
Before describing seal member 1 of the present invention, the sound insulation effect will be described for a seal member of the prior art that is made up of only tube 6 and that does not have porous body 7 as shown in
Seal member 1 of Embodiment 1 of the present invention is next described. This seal member 1 is the example shown in
In seal member 1 of Embodiment 2 of the present invention shown in
In seal member 1 of Embodiment 3 of the present invention shown in
In seal member 1 of Embodiment 4 of the present invention shown in
In seal member 1 of Embodiment 5 of the present invention shown in
In seal member 1 of Embodiment 6 of the present invention shown in
In seal member 1 of Embodiment 7 of the present invention shown in
In seal member 1 of Embodiment 8 of the present invention shown in
In seal member 1 of Embodiment 9 of the present invention shown in
Comparative examples are next described for comparison with Embodiments 1-9 of the present invention.
In the seal member of Comparative Example 1 shown in
In the seal member of Comparative Example 2 shown in
In seal member 1 of Comparative Example 3 shown in
In seal member 1 of Comparative Example 4 shown schematically in
In Comparative Example 5 shown schematically in
The seal members of Embodiments 1-9 and Comparative Examples 1-3 described above are of configurations in which porous body 7 is arranged along the entire length of tube 6. However, the present inventors found that in some cases, sound insulation effects could be obtained that are superior to the seal member (
In seal member 1 of Embodiment 10 of the present invention, porous body 7 that has a cross-sectional shape measuring 2 mm×10 mm is inserted in the interior of hollow tube 6 of linear form or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 11 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 12 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×20 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 13 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×5 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 14 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×2.5 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 15 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 16 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 17 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 18 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 19 of the present invention, porous body 7, in which the cross-sectional shape measures 8 mm×13 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 6 (
In seal member 1 of Embodiment 20 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is polyurethane foam identical to Embodiment 1 (
In seal member 1 of Embodiment 21 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is polyurethane foam identical to Embodiment 1 (
In seal member 1 of Embodiment 22 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is polyurethane foam identical to Embodiment 1 (
In seal member 1 of Embodiment 23 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is polyurethane foam identical to Embodiment 1 (
In seal member 1 of Embodiment 24 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is polyurethane foam identical to Embodiment 3 (
In seal member 1 of Embodiment 25 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is polyurethane foam identical to Embodiment 2 (
In seal member 1 of Embodiment 26 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is foamed rubber identical to Embodiment 8 (
Comparative examples for comparison with Embodiments 10-26 of the present invention are next described.
In seal member 1 of Comparative Example 6, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Comparative Example 7, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted in the interior of hollow tube 6 of linear or curved form and having both ends open. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
As described above, Embodiments 1-26 of the present invention exhibit excellent sound insulation performance in the range of frequencies of high-frequency noise (approximately 2000 Hz-approximately 16000 Hz) produced by electric motors that are used in electric vehicles or hybrid vehicles in particular. The realization of this superior sound insulation performance by Embodiments 1-26 is the effect exerted by the sound-absorbing effect of porous body 7 together with the vibration damping realized by the air in air-holding space 8. In contrast, in the prior-art example in which a porous body is not provided, sufficient sound insulation performance is not obtained because, despite the vibration damping effect realized by the air in tube 6, there is no sound absorbing effect realized by porous body 7. In Comparative Example 3 in which air-holding space is not present in tube 6, sufficient sound insulation performance is not obtained because there is no vibration damping effect realized by the air in tube 6, despite the sound-absorbing effect realized by porous body 7. In Comparative Examples 4 and 5 in which porous body 7 is positioned outside tube 6, because the vibration of air is conveyed via the side of porous body 7 that is positioned in open space, only an extremely small portion of the propagated air vibration is affected by the sound-absorbing effect of porous body 7, and sufficient sound insulation performance is not obtained.
In addition, of the seal members in which porous body 7 and air-holding space are provided inside tube 6, it is conceivable that the material that was used in Comparative Examples 1 and 2 was not suitable because Comparative Examples 1 and 2 were not able to realize sufficient sound insulation performance. In other words, when the material of Comparative Examples 1 and 2 is reexamined, it is determined that the bulk density is higher than in Embodiments 1-26. This high density of porous body 7 indicates that the sum total of the hole portions within a fixed sectional area of porous body 7 is low, and fewer hole portions gives rise to a lower sound-absorbing effect. Accordingly, in order to realize higher sound insulation performance, the density of porous body 7 is preferably lower. After taking into consideration that the sound insulation performance of Comparative Examples 1 and 2 is limited and the sound insulation performance of Embodiment 7 is within the permissible range, the bulk density can be said to preferably be no greater than 150 kg/m3. However, when the density is too low, the material strength of porous body 7 decreases, raising the possibility of problems in processing or attachment, and the bulk density is therefore preferably at least 10 kg/m3.
Focusing on the water absorption coefficient of the material that makes up porous body 7, it is believed that the quantity of continuous vacancies increases with a higher water absorption coefficient, and that high sound insulation performance is difficult to achieve when the water absorption coefficient is too low due to the scarcity of continuous vacancies. Comparing the water absorption coefficients of Embodiments 1-26 and Comparative Examples 1 and 2, it is believed possible that sufficient sound insulation performance cannot be obtained when the water absorption coefficient is not greater than 1.6%. Still further, in order to more reliably obtain adequate sound insulation performance, the water absorption coefficient should preferably be about 10% or more. However, when the water absorption coefficient becomes too high, not only does the absorption of the water that infiltrates from gaps increase the weight, but the blockage of the continuous vacancies prevents the realization of the water absorption coefficient is therefore preferably no greater than 3000%.
Focusing on the compression stress that is one characteristic of the material that makes up porous body 7, the 25% compression stress of porous body 7 of seal member 1 for which superior sound insulation performance was obtained was approximately 1 N/cm2 or less. In addition, the 50% compression stress of porous body 7 of seal member 1 for which superior sound insulation performance was obtained was approximately 2.5 N/cm2 or less.
As described above, in order to obtain superior sound insulation performance in seal member 1 of the present invention, the conditions must be met in which the bulk density be 10 kg/m3 or more but no greater than 150 kg/m3, the water absorption coefficient be 10% or more but no greater than 3000%, the 25% compression stress be no greater than 1 N/cm2, and the 50% compression stress be no greater than 2.5 N/cm2. Nevertheless, even if not all of these conditions are met, the effect of a certain level of improvement in sound insulation performance is obtained if at least one of these conditions is satisfied, and such cases are therefore included within the scope of present invention.
The sound insulation performance of seal member 1 of the present invention has been described hereinabove, but characteristics other than the sound insulation performance will next be described. Vehicle doors or building doors that are the chief use of seal member 1 of the present invention require reduction of weight, as previously described. Tube 6 of seal member 1 of the present invention is a component similar to the prior-art example, and only the addition of porous body 7 that is inserted into this tube 6 increases the weight of seal member 1. Accordingly, this porous body 7 should preferably be as light as possible. There is no great difference in the cross-sectional area among nearly all of Embodiments 1-9 and Comparative Examples 1-5, and the low density of porous body 7 prevents or reduces an increase of the weight of seal member 1. In other words, as described above, setting the bulk density to be no greater than 150 kg/m3 is also effective for preventing or reducing an increase of the weight of seal member 1. Setting the bulk density low as described above obtains the extremely superior effect of achieving an increase of the sound insulation performance without greatly increasing the weight. In a seal member of the prior art, a seal member having high sound insulation performance typically tends to have greater weight. However, an examination of Table 1 reveals that the seal member of the present invention has superior sound insulation performance despite being clearly lighter than Comparative Examples 1-3 that have poor sound insulation performance. The present invention therefore achieves the particular effect of simultaneously realizing sound insulation performance and reduced weight, an achievement that was problematic in the prior art.
In addition, seal member 1 of the present invention does not involve complex manufacturing steps for seal member 1 and does not increase the number of components because porous body 7 that is to be inserted in the interior of tube 6 does not need to be inserted beforehand into, for example, a waterproof tube. Further, when porous body 7 is formed from a material having low compression stress as previously described, porous body 7 can be easily mounted and seal member 1 can be easily compressed during use, meaning not only that the workability is excellent, but that the reliability of the seal (resistance to heat and weather) is excellent due to the ability to easily achieve a good seal between the outer peripheral portion of door body 2a and 4a and door frame 3a and 5a with a small amount of force.
In Embodiments 10-26 of the present invention, porous body 7 is not arranged along the entire length of tube 6, as shown in
Hollow tube 6 in linear form or curved form having two end openings as shown in
A tube member (for example, upper tube member 6a) that is joined with another tube member (for example, lower tube member 6b) by way of corner joint 6c typically has two opened end portions for the sake of convenience of the forming and joining steps. A seal member that includes this type of tube member conventionally encounters difficulty in realizing high sound insulation performance due to sound leakage from the open end portions of the tube members. In this regard, porous body 7 prevents or reduces sound leakage from the open end portions in the above-described Embodiments 10-26. An examination of Table 2 reveals that an improvement in sound insulation performance is obtained when at least a portion of porous body 7 is present within a range of distance of 33% of the entire length of a tube member from the open end portions.
This insertion of porous body 7 into the interior of hollow tube 6 is effective both in loop-shaped seal member 1 that is closed as shown in
Seal member 1 of the present invention described above is not limited to a configuration that is to be mounted on the outer peripheral portion of a vehicle door body or building door body and may also be mounted on the inner side of a door frame. In addition, seal member 1 of the present invention may also be a component for sealing that is mounted on the outer peripheral portion of a housing portion for a vehicle drive device, such as the gasoline engine or electric motor of an automobile, and that is compressed against the chassis frame. Still further, the range of application of the seal member of the present invention is not limited and seal member 1 can be used in various members that require sealing in, for example, an electrical appliance.
The manufacturing method of seal member 1 of the present invention is next described. This method is for manufacturing seal member 1 of a configuration in which porous body 7 is arranged in the interior of hollow tube 6 that is a composite member configured by joining a plurality of tube members 6a and 6b (components) by way of joint 6c as described above.
Normally, when forming hollow tube 6 that is a composite member, a plurality of tube members that are hollow components are joined by way of joints. As one example, one tube member is fitted onto one end portion of a rod-shaped (cylindrical) core for forming the hollow portion of a joint, and the other tube member is fitted onto the other end portion of the core. An unvulcanized rubber layer or a resin layer is then formed to cover the outer circumference of the core, and heat and pressure are applied to realize vulcanization-bonding of the rubber layer or heat and pressure are applied followed by cooling and pressurizing to solidify the resin layer and thus form a joint that is made up from an elastically deformable vulcanized rubber layer or resin layer.
In the present invention, preceding the formation of joint 6c and the joining of tube members 6a and 6b, previously described porous body 7 is inserted in advance into the interiors of tube members 6a and 6b as shown in
In another example, core 16 that is attached to tube members 6a and 6b into which porous body 7 has been inserted as previously described is placed inside cavity 20a of die 20 of the injection-molding device shown in
According to the manufacturing method described above, when setting die 17 in a press and then applying heat and pressure to bring about vulcanization bonding or heat bonding of unvulcanized rubber sheet or resin sheet, or when injecting melted unvulcanized rubber or resin into cavity 20a of die 20 and then vulcanizing or solidifying, porous body 7 is bonded and secured to the inner surface of tube 6 (tube members 6a and 6b and joint 6c) as shown in
Porous body 7 inside tube members 6a and 6b is preferably in contact with core 16 before bonding, because porous body 7 is heated in a state of being pressed by core 16 against tube members 6a and 6b and joint 6c, thus readily bonds with tube members 6a and 6b and joint 6c. In addition, even if porous body 7 is accommodated inside tube members 6a and 6b at the time of insertion into tube members 6a and 6b, porous body 7 that is heated and melts or softens may flow from the interior of tube members 6a and 6b to as far as the point of contact with the inner surface of joint 6c and bond to the inner surface of joint 6c. Nevertheless, porous body 7 may also be inserted into only tube members 6a or tube member 6b, or porous body 7 may be bonded only to the inner surfaces of tube members 6a and 6b without reaching a position that contacts joint 6c.
One additional effect realized by this manufacturing method is the ease of extracting core 16 after tube members 6a and 6b are joined by way of joint 6c. This effect is realized because porous body 7 that is made up of a sponge material, as represented by polyurethane foam, or nonwoven fabric causes less friction than the inner surfaces of tube members 6a and 6b and joint 6c, and as a result, when extracting core 16 from slit part 19, core 16 slips over the contact surface with porous body 7 and can be smoothly extracted.
As the material of tube members 6a and 6b and joint 6c described above, a synthetic rubber such as EPDM (ethylene propylene diene rubber) or an olefin-based thermoplastic elastomer (for example, Milastomer (Trade Name) of Mitsui Chemicals, Inc.) are typical, but the present invention is not limited to these materials. In addition, tube members 6a and 6b and joint 6c may also be formed from the same material but may also be formed from different materials. Porous body 7 may be formed from any of the materials of each of the above-described embodiments. Joint 6a, 6b may be a curved corner joint such as shown in
Embodiments of seal members that have been manufactured by this manufacturing method and comparative example are next described to clarify the effects of the seal member manufacturing method described hereinabove.
In seal member 1 of Embodiment 27 of the present invention, porous body 7, in which the cross-sectional shape measures 10 mm×10 mm, is inserted into, of the entire 840 mm-length of a linear tube member 6a, only portions that are within 210 mm of each of the two end portions, and the two end portions of tube member 6a are each joined to 100 mm-tube member 6b by way of L-shaped joints 6c. The material that makes up this porous body 7 is polyurethane foam identical to Embodiment 1 (
In seal member 1 of Embodiment 28 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted into, of the entire 840 mm-length of a linear tube member 6a, only portions that are within 210 mm of the two end portions, and the two end portions of tube member 6a are joined to 100 mm-tube member 6b by way of L-shaped joints 6c. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Embodiment 29 of the present invention, porous body 7, in which the cross-sectional shape measures 2 mm×10 mm, is inserted into, of the entire 840 mm-length of a linear tube member 6a, only portions that are within 210 mm of the two end portions, and the two end portions of tube member 6a are joined to 100 mm-tube member 6b by way of L-shaped joints 6c. The material that makes up this porous body 7 is nonwoven fabric identical to Embodiment 5 (
In seal member 1 of Comparative Example 8, porous body 7 is not inserted into the entire 840 mm-length of linear tube member 6a, and tube member 6a is joined at two end portions to 100 mm-tube member 6b by way of L-shaped joints 6c. Joint 6c is fabricated by wrapping an unvulcanized EPDM (Ethylene Propylene Diene rubber) composition in sheet form that contains a vulcanizing agent and foaming agent around each core, and then applying heat and pressure in a press to vulcanize the EPDM, in the state where tube members 6a and 6b are linked with each other by way of the core. After forming joint 6c, a portion of each joint 6c is cut to produce slit part 19, and core 16 is extracted from this slit part 19. The amount of sound insulation for sounds of various frequencies in the state where this seal member 1 is used is 38.4 dB at 4000 Hz, 44.3 dB at 5000 Hz, 46.6 dB at 6300 Hz, 50.2 dB at 8000 Hz, and 50.6 dB at 10000 Hz; and the average decibel value of the amount of sound insulation for 4000 Hz-10000 Hz is 47.7 dB. These results are shown in Table 3.
As described above, the seal member that is manufactured by the method of the present invention, i.e., the seal member of Embodiments 27-29, obtains the effect of exhibiting superior sound insulation performance in the range of 4000 Hz-10000 Hz with respect to the seal member of Comparative Example 8 that does not include a porous body. This effect is believed to result from the adhesion of porous body 7 in the vicinity of slit part 19, whereby porous body 7 is reliably positioned at the location at which a sound-absorbing effect is particularly desired and a sound insulation effect can be efficiently obtained.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-098932 | May 2016 | JP | national |
| 2016-224233 | Nov 2016 | JP | national |
| 2017-020489 | Feb 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/018356 | 5/16/2017 | WO | 00 |
