JP2016225127A - Seal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal material which has conductivity, enables easy downsizing of a connector, is less likely to be damaged, and has high sealability.SOLUTION: A seal material 10 includes an elastic part 20 having rubber elasticity and a metal conductive part 30 disposed in the elastic part 20. The seal material 10 is disposed between a first connection member 51 and a second connection member 61. A first surface 15, which contacts with the first connection member 51, and a second surface 16, which contacts with the second connection member 61, from among surfaces of the seal material 10, are electrically connected by the metal conductive part 30.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sealing material used for a waterproof connector of an automobile.

  In the wiring of wire harnesses such as automobiles, if moisture penetrates inside the wire sheath, the lead wire will corrode, or the conductive part will corrode due to moisture reaching the electronic control unit and will not operate. In addition, malfunction due to moisture-based short-circuiting or component destruction may occur. For this reason, if moisture enters the inside of the wire covering in the wire harness, the normal operation of the automobile may be hindered. Therefore, in order to prevent water from entering the wire harness, it is necessary to provide a waterproof / water stop function between the connection member such as the housing and the electric wire. In particular, when connecting using a connector, it is necessary to provide a waterproof / waterproof function between a connection member such as a housing and the connector housing, and between the electric wire and the connector housing. This waterproof / water stop function is, for example, a sealing material such as an O-ring interposed between a connecting member such as a housing and the connector housing, or a seal such as a rubber plug interposed between the electric wire and the connector housing. Brought by the material.

  By the way, in recent years, in a waterproof connector for an automobile, a technique for grounding a connection member such as a motor housing and a connector housing through the sealing material by imparting conductivity to the sealing material such as an O-ring has been proposed. . Earthing is said to have the effect of reducing electromagnetic noise generated inside and outside the part. For this reason, in recent years, various techniques for imparting conductivity to a sealing material such as an O-ring have been proposed.

  For example, Patent Document 1 includes a base portion made of a rubber-like elastic body and a conductive portion in which the conductor is oriented in a daisy chain in the conductive direction, and is sandwiched between the connection members so that the connection members are electrically connected to each other. A columnar elastic connector to be connected is disclosed.

  In the elastic connector disclosed in Patent Document 1, the conductors in the conduction portion are oriented in a daisy chain in the conduction direction, so that the conductors in the conduction portion and the conductors and connection members in the conduction portion are electrically connected. Connected. The electrical connection between the conductor in the conducting portion and the connecting member is performed by interposing a reinforcing core material or a metal foil layer between the conducting portion and the connecting member. Patent Document 1 discloses that this elastic connector is unlikely to buckle even if connection members that are relatively apart from each other are conductively connected.

JP 2013-26140 A JP 2009-123484 A JP 2014-17219 A JP 2012-243914 A Japanese Utility Model Laid-Open No. 04-13297

  However, the elastic connector disclosed in Patent Document 1 is a contact portion between conductors in the conducting portion, or a contact portion between the conductor in the conducting portion and another member such as a reinforcing core member or a metal foil layer. , Contact resistance is generated, and the conductivity tends to be low. For this reason, in order to sufficiently increase the conductivity of the elastic connector disclosed in Patent Document 1, the conductive portion of the elastic connector is enlarged, or the two connecting members and the elastic connector are pressed with an excessive force. It is necessary to increase the contact area between the members. Further, in order to sufficiently increase the conductivity of the elastic connector disclosed in Patent Document 1, it is necessary to increase the content of the conductor in the conducting portion.

  However, the increase in the size of the conducting portion of the elastic connector has a problem that it is contrary to the demand for downsizing of devices that have been required in recent years. Further, when the connecting member and the elastic connector are pressed with an excessive force, there is a problem that the conductive portion of the elastic connector is easily damaged. Furthermore, when the content of the conductor in the conducting part is increased, there is a problem that the conducting part becomes hard and the sealing performance is likely to be lowered.

  As described above, the conventional elastic connector has problems that it is difficult to reduce the size, the conductive portion is easily damaged, and the sealing performance is easily deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sealing material that has conductivity, is easy to miniaturize a connector, hardly breaks, and has high sealing properties.

  A sealing material according to a first aspect of the present invention includes an elastic portion having rubber elasticity, and a metal conductive portion disposed in the elastic portion, and includes a first connecting member and a second connecting member. A sealing material interposed therebetween, and among the surfaces of the sealing material, the first surface that contacts the first connecting member and the second surface that contacts the second connecting member are It is electrically connected by a metal conductive part.

  The sealing material according to a second aspect of the present invention is the sealing material according to the first aspect, wherein the metal conductive portion has a porosity of 80% or more, and the end portion of the metal conductive portion is the first surface. And the second surface.

The sealing material according to the third aspect of the present invention is characterized in that, in the sealing material of the first or second aspect, the volume resistivity of the metal conductive portion is 1 × 10 ⁻³ Ω · cm or less. To do.

  The sealing material of the present invention has electrical conductivity, the connector can be easily downsized, is not easily damaged, and has high sealing performance.

It is a figure which shows the connector in which the sealing material which concerns on 1st Embodiment is used. FIG. 1A is a cross-sectional view of a connector in which the sealing material according to the first embodiment is used, and is an enlarged cross-sectional view of a region P shown in FIG. FIG. 1B is a diagram illustrating a state in which the connector illustrated in FIG. It is a figure which shows the sealing material which concerns on 1st Embodiment. FIG. 2A is a plan view of the sealing material according to the first embodiment, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. It is an enlarged view of the sealing material shown in FIG. 3A is a cross-sectional view taken along the line BB in FIG. 2A, and FIG. 3B is an enlarged view of a region Q shown in FIG.

  Hereinafter, embodiments of the sealing material of the present invention will be specifically described with reference to the drawings.

[First Embodiment]
(Seal material)
FIG. 1 is a view showing a connector 50 in which the sealing material 10 according to the first embodiment is used. FIG. 1A is a cross-sectional view of a connector 50 in which the sealing material 10 is used, and is an enlarged cross-sectional view of a region P shown in FIG. FIG. 1B is a view showing a motor 60 to which the connector 50 shown in FIG. FIG. 2 is a view showing the sealing material 10. 2A is a plan view of the sealing material 10, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A.

  As shown in FIG. 1, the sealing material 10 according to the first embodiment is interposed between a housing 61 of a motor 60 and a connector housing 51 of a connector 50 that connects an electric wire 70 to the motor 60. A shaft 62 passes through the housing 61 of the motor 60. The sealing material 10 is interposed between the connector housing 51 as the first connection member and the motor casing 61 as the second connection member, and between the connector housing 51 and the motor casing 61. It is to be sealed.

  The connector 50 is an electrical connection in which a connector housing 51 in which a recess 52 for accommodating the sealing material 10 is formed, and an electric wire 70 and a terminal 80 in which a core wire 71 is crimped by a crimping portion 56 are sealed with resin and attached to the connector housing 51. Part 55. Here, the electric wire 70 is covered with an electric wire shield layer 75 that blocks noise generation. The sealing material 10 seals between the connector housing 51 and the motor casing 61 by being pressed by the motor casing 61 while being accommodated in the recess 52 formed in the connector housing 51.

  As shown in FIG. 2, the sealing material 10 is formed in a substantially rectangular ring shape. Further, the sealing material 10 includes a shape of the top surface 15 that is a first surface that contacts the connector housing 51 among two surfaces in a direction in which the sealing material 10 looks like a substantially rectangular ring shape, and a housing of the motor. The shape of the bottom surface 16 which is the second surface in contact with 61 is different. Specifically, the top surface 15 is formed with a groove 12 having an arc-shaped cross section formed along the longitudinal direction of the sealing material 10, but the bottom 16 is not formed with a groove and the bottom 16 is flat. It has become.

  FIG. 3 is an enlarged view of the sealing material 10 shown in FIG. 3A is a cross-sectional view taken along the line BB in FIG. 2A, and FIG. 3B is an enlarged view of a region Q shown in FIG. As shown in FIGS. 3A and 3B, the sealing material 10 includes an elastic portion 20 having elasticity and a metal conductive portion 30 disposed in the elastic portion 20.

<Elastic part>
The elastic part 20 is made of a material having rubber elasticity. As the material having rubber elasticity, one or more selected from the group consisting of rubber, thermoplastic elastomer, gel material and soft resin can be used.

  As rubber, for example, synthesis of isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber, acrylic rubber, polyisobutylene, butyl rubber, ethylene propylene rubber, epichlorohydrin rubber, urethane rubber, silicone rubber, fluorine rubber, etc. Rubber is used.

  As the thermoplastic elastomer, for example, a styrene thermoplastic elastomer, an olefin thermoplastic elastomer, a vinyl chloride thermoplastic elastomer, a urethane thermoplastic elastomer, an ester thermoplastic elastomer, or an amide thermoplastic elastomer is used.

  As a gel-like thing, what contains well-known resin components, such as a silicone type resin and a urethane type resin, is used, for example. As the soft resin, for example, a soft resin containing a known resin component such as an ethylene-vinyl acetate copolymer resin in addition to the rubber and the thermoplastic elastomer is used.

  The material having rubber elasticity may contain an additive in addition to rubber, thermoplastic elastomer, gel-like material, soft resin and the like. As the additive, for example, a tackifier, a softener, a curing agent, a flame retardant, and a coupling agent are used.

<Metal conductive part>
The metal conductive portion 30 is disposed in the elastic portion 20. The metal conductive portion 30 is made of a metal fluff or a foam metal. Here, the foam metal is a sponge-like metal structure having a large amount of small spaces. As the metal cotton-like material, for example, fine metal wires such as steel wool and copper are used. As the foam metal, for example, a metal foam such as aluminum or copper is used. The foam metal is obtained, for example, by gas foaming or sintering. That is, the foam metal does not have to be foamed as a manufacturing method, and may be a metal structure including continuous voids.

As a metal used for a metal fluff or a foam metal, what has high electroconductivity is used. Specifically, the metal used for the metal floc or foam metal has a volume resistivity of preferably 1 × 10 ⁻³ Ω · cm or less, more preferably 1 × 10 ⁻⁵ Ω · cm or less. . When the volume resistivity is within this range, the conductivity of the sealing material 10 tends to be high.

  The metal conductive part 30 has a porosity of preferably 80% or more, more preferably 90% or more. Here, the porosity of the metal conductive portion 30 is based on the assumption that the elastic portion 20 does not exist in the gap between the metal flocs or the foam metal constituting the metal conductive portion 30 disposed in the elastic portion 20. It means the porosity of metal fluff or foam metal. Specifically, the porosity of the metal conductive portion 30 is a metal floc or foam relative to the apparent volume of the metal floc or foam metal constituting the metal conductive portion 30 in the state of being disposed in the elastic portion 20. It means the proportion of the volume occupied by voids present in the metal. The porosity of the metal conductive part 30 can be calculated, for example, by measuring the apparent volume of the metal cotton-like material or foam metal before being disposed in the elastic part 20 and the volume occupied by the gap.

<End of metal conductive part>
As shown in FIGS. 3 (A) and 3 (B), the metal conductive portion 30 constituting the sealing material 10 has an end portion 32 (32a, 32b) that is a first surface that contacts the connector housing 51. It is exposed to the surface 15 and the bottom surface 16 as the second surface that contacts the housing 61 of the motor. Specifically, a large number of one end portions 32a of the metal conductive portion 30 are dotted and exposed on the top surface 15 that is the first surface, and the other end of the metal conductive portion 30 is exposed on the bottom surface 16 that is the second surface. Many end portions 32b are dotted and exposed. Therefore, in the sealing material 10, the top surface 15 that is the first surface and the bottom surface 16 that is the second surface are electrically connected by the conductive metal conductive portion 30.

  When the metal conductive portion 30 is a metal fluff, the metal fluff is formed as long as the top surface 15 as the first surface and the bottom surface 16 as the second surface are electrically connected. All of the metal fibers may not be exposed to the top surface 15 that is the first surface and the bottom surface 16 that is the second surface.

<Content ratio of elastic part and metal conductive part in sealing material>
In the sealing material 10, the elastic portion 20 is filled in the gap of the metal conductive portion 30. For this reason, the content ratio of the elastic part 20 and the metal conductive part 30 in the sealing material 10 is substantially the same as the volume ratio of the porosity of the metal conductive part 30 and the metal part of the metal conductive part 30. Specifically, the volume ratio of the elastic part 20 is preferably 80% or more, more preferably 90% or more, and the volume ratio of the metal conductive part 30 is preferably less than 20%, more preferably less than 10%. It is preferable that the volume ratio of the elastic portion 20 is 80% or more and the volume ratio of the metal conductive portion 30 is less than 20% because the sealing material 10 has sufficient elasticity and high sealing performance.

<Manufacture of sealing materials>
The sealing material is manufactured by molding by a known molding method using, for example, a rubber-elastic material constituting the elastic portion 20 or a raw material thereof, and a metal fluff or foam metal constituting the metal conductive portion 30. can do. Specifically, after placing or mixing a metal floc or foam metal in a rubber elastic material or its raw material, it is molded by a molding method such as press molding, injection molding or extrusion molding using a mold. Can be manufactured.

<Conductivity of sealing material>
The sealing material 10 has a volume resistivity measured between the top surface 15 as the first surface and the bottom surface 16 as the second surface of 1 × 10 ⁻⁶ to 1 × 10 ⁻³ Ω · cm. Is preferred. When the volume resistivity is within this numerical range, the electrical conductivity between the connector housing 51 as the first connection member and the motor housing 61 as the second connection member becomes good.

  The sealing material according to the present invention can be used for, for example, a connector packing, an O-ring, and a gasket that are connected to a connection member such as a vehicle motor, an engine, a transmission, and a body while having conductivity.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

[Example 1]
100 parts by mass of silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., KE-2017-30A / B) and 75 parts by mass of nickel foam metal (nickel foam metal having a porosity of 92% foamed by gas foaming), The sealing material 10 shown in FIG. 2 was introduced into a mold for molding. And the mixture in a shaping | molding die was press-molded for 10 minutes at 170 degreeC, and the sealing material of the same shape as the sealing material 10 shown in FIG. 2 was shape | molded. The nickel foam metal has the porosity and volume resistivity shown in Table 1.

  Table 1 shows the blending amounts of silicone rubber and nickel foam metal. In addition, the ratio of the blending amount of the silicone rubber and the nickel foam metal shown in Table 1 matches the ratio of the content of the silicone rubber and the nickel foam metal in the obtained sealing material. The relationship in which the blending amount and the content are the same applies to the following examples and comparative examples.

  About the obtained sealing material, the volume resistivity between the front and back in the sealing direction, that is, between the top surface 15 and the bottom surface 16 of the sealing material 10 shown in FIG. 2 was measured.

  Further, the sealing property of the obtained sealing material 10 was examined. Evaluation of sealing performance was performed as follows. First, the sealing material 10 was molded into a packing shape and set in the recess 52 of the connector 50. Next, the protruding portion of the connector housing 51 in which the terminal 80 was formed in the connector 50 in which the sealing material 10 was set was fitted into a hole formed in the housing 61 of the motor. Then, a pressure of 200 KPa is applied to the hole formed in the motor casing 61 using compressed air, and whether or not the air leaks to the outside of the motor casing 61 through the packing-shaped sealing material 10. Examined. Specifically, a case where no air leaked from the sealing material 10 at 200 KPa when pressure was applied with compressed air was evaluated as ◯. On the other hand, when pressure was applied with compressed air, air leaked from the sealing material 10 at less than 200 KPa was evaluated as x.

  Table 1 shows these results. Evaluations similar to those of Example 1 were performed for the following examples and comparative examples. The results are shown in Table 1.

[Example 2]
A nickel foam metal having a porosity of 84% foamed by gas foaming was used in place of the nickel foam metal having a porosity of 92% foamed by gas foaming. In the same manner as in Example 1, a sealing material was molded.

[Example 3]
Instead of nickel foam metal, steel wool (manufactured by Nippon Steel Wool Co., Ltd., average wire diameter 40 μm, porosity 84%) was used, and this steel wool was changed to the blending amount shown in Table 1, and the same as in Example 1. Thus, a sealing material was formed.

[Comparative Example 1]
A sealing material was prepared in the same manner as in Example 1 except that an aluminum foam metal having a porosity of 50% produced by sintering was used instead of the nickel foam metal and the aluminum foam metal was blended as shown in Table 1. Molded.

[Comparative Example 2]
Example except that stainless steel filler (manufactured by Fukuda Metal Foil Powder Co., Ltd., SUS-316-L350, particle diameter of 45 μm or less) was used instead of nickel foam metal, and this stainless steel filler was changed to the blending amount shown in Table 1. In the same manner as in No. 1, a sealing material was molded.

[Comparative Example 3]
A carbon filler (manufactured by Lion Corporation, Ketjen Black EC600JD, average particle size 0.03 μm) was used in place of the nickel foam metal, and this carbon filler was changed to the blending amount shown in Table 1 and was the same as Example 1. Thus, a sealing material was formed.

  As mentioned above, although this invention was demonstrated by embodiment, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.

DESCRIPTION OF SYMBOLS 10 Sealing material 11 Sealing material main body 12 Groove part 15 Top surface (1st surface)
16 Bottom (second surface)
20 Elastic part 30 Metal conductive part 32, 32a, 32b End part 50 of metal conductive part Connector 51 Connector housing (first connecting member)
52 Concave portion 55 Electrical connection portion 56 Crimp portion 60 Motor 61 Motor housing (second connection member)
62 Shaft 70 Electric wire 71 Core wire 75 Electric wire shield layer 80 Terminal

Claims (3)

An elastic part having rubber elasticity;
A metal conductive portion disposed in the elastic portion;
A sealing material interposed between the first connecting member and the second connecting member,
Of the surfaces of the sealing material, a first surface that contacts the first connecting member and a second surface that contacts the second connecting member are electrically connected by the metal conductive portion. A sealing material characterized by that. The porosity of the metal conductive part is 80% or more,
2. The sealing material according to claim 1, wherein an end portion of the metal conductive portion is exposed at the first surface and the second surface. 3. The sealing material according to claim 1, wherein the volume resistivity of the metal conductive portion is 1 × 10 ⁻³ Ω · cm or less.

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