JP4646260B2 - Automotive harness with terminal - Google Patents

Description

  The present invention relates to a terminal-equipped automobile harness having a waterproof structure in which conductors are filled with a sealing material.

  The temperature in the engine room of an automobile rises while the engine is running due to traveling or the like, and falls when the engine is stopped. For this reason, in an automobile harness, for example, an automobile harness wired through a bulkhead that partitions between an engine room and a vehicle compartment, it has entered the engine room from the outside due to a pressure difference caused by a temperature difference in the engine room. In some cases, moisture penetrated into the terminal portion of the automobile harness.

  Therefore, in an automobile harness, a cap is provided at a concentrated joint portion where a terminal portion and a plurality of conductors are bundled and welded, and liquid silicone rubber is poured into the cap, and a sealing material is provided at the concentrated joint portion, such as The intrusion of moisture was prevented.

  By the way, there is one using silver paste or the like as a sealing material, but it is very expensive. On the other hand, the liquid silicone rubber is a low price and has no influence on the manufacturing process of the automobile harness, so it is an extremely simple waterproof measure. However, since conventional liquid silicone has a relatively high viscosity, the gap between the welded portions of the concentrated joint portion may not be sufficiently filled, and it may be severely affected by temperature cycles, humidity, mechanical vibrations, etc. like an automobile harness. In such a use environment, there was a problem in terms of reliability because the adhesiveness with the terminal portion or the like was lowered and the waterproofness was insufficient.

  The present invention has been made in view of the above problems, and provides a terminal-equipped automobile harness having a waterproof structure in which a conductor is filled with a sealing material capable of exhibiting sufficient waterproofness even in a severe use environment. The purpose is to do.

  In order to achieve the above-mentioned object, the present inventors diligently studied the above-mentioned problems related to the liquid silicone rubber. As a result, if the liquid silicone rubber used as the sealing material penetrates into the conductor of the automobile harness without any gaps, it can prevent a decrease in adhesiveness, prevent water from entering, and have a lower viscosity and more easily penetrate. Further, the present inventors have found the fact that the lower the viscosity, the lower the hardness at the time of curing, and the better the adhesion and the better the adhesion can be achieved.

That is, in order to achieve the above object in the present invention, a terminal-equipped automobile harness having a waterproof structure in which conductors are filled with a sealing material,
(A) an automobile harness comprising a conductor and an insulation coating;
(B) The conductor portion and the insulation coating portion exposed by removing the insulation coating from the automobile harness were respectively attached to the conductor portion and the insulation coating portion by gripping with the wire barrel and the insulation barrel. A terminal with the wire barrel and the insulation barrel;
(C) comprising the sealing material,
(I) The above-mentioned sealing material is a solvent-free type one-component curing type having an elastic modulus at 25 ° C. in the range of 0.55 to 0.8 MPa, and deacetication in a classification based on a compound generated during the condensation reaction. Consists of condensation type liquid silicone rubber excluding type,
(Ii) A terminal-equipped automobile harness characterized in that the sealing material is provided so as to continuously cover the conductor and the insulating coating between the wire barrel and the insulation barrel. Preferably, the automobile harness is a ground wiring, and a ground terminal is attached to the exposed conductor. More preferably, the elastic modulus is 0.55 to 0.72 MPa.

Preferably, it is an automobile harness with a terminal having a waterproof structure in which a conductor is filled with a sealing material,
(A) a plurality of automobile harnesses made of a conductor and an insulation coating;
(B) a concentration joint portion in which a plurality of conductor portions exposed by removing the insulation coating from the plurality of automobile harnesses are bundled;
(C) comprising the sealing material,
(I) The above-mentioned sealing material is a solvent-free type one-component curing type having an elastic modulus at 25 ° C. in the range of 0.55 to 0.8 MPa, and deacetication in a classification based on a compound generated during the condensation reaction. Consists of condensation type liquid silicone rubber excluding type,
(Ii) The automotive harness with terminals, wherein the sealing material is provided so as to continuously cover the conductor and the insulating coating. More preferably, the sealing material is any one of a dehydrogenation type, a dealcoholization type, a deoxime type, a deketone type, a deamine type, a deamid type, and a dehydroxyamine type in the classification based on the compound generated during the condensation reaction. It is the automobile harness with a terminal characterized by being. Particularly preferably, the elastic modulus is 0.55 to 0.72 MPa.

  At the time of curing, a liquid silicone rubber having an elastic modulus of 0.8 MPa or less at 25 ° C. is applied to the exposed joint where the harness conductor of the ground terminal is exposed and the concentrated joint part where a plurality of conductors of the ground wiring are bundled, and then sealed. When the material is provided, the adhesion is improved and unlike conventional silicone rubber, even if a temperature cycle or humidity cycle test is performed, the adhesion to the terminal part etc. does not decrease and the water tightness for a long time is maintained. Is done.

  This is because the liquid silicone rubber used as the sealing material of the present invention has a relatively low viscosity and is easy to penetrate, and the exposed portion where the conductor of the automobile harness is exposed, the concentrated joint portion, and the gap between the core wires constituting the conductor are ensured. It has sufficient flexibility against strain caused by curing shrinkage and distortion caused by expansion and shrinkage caused by temperature change in the insulation coating of the conductor due to improved adhesion and easy to follow these strains It depends.

  That is, the conventional sealing material may not be able to sufficiently fill the gaps between the conductors, and is not necessarily used for synthetic resins such as polyvinyl chloride (PVC) and polyolefin used for insulation coating of automobile harnesses. Does not have good adhesion. In addition, in the case of an automobile harness using PVC insulation coating, conventional silicone rubber is affected by adhesiveness, and thus water tightness, even if a slight distortion occurs because the plasticizer of PVC lowers the adhesive strength. easy.

  On the other hand, the sealing material of the present invention can reliably fill the gap between the conductors, has sufficient flexibility against distortion, and exposes the exposed portion of the automobile harness even in a severe environment where the temperature changes rapidly. Since the adhesive strength between the concentrated joint portion and the insulating coating is maintained over a long period of time, it is extremely suitable as a material for maintaining watertightness.

  Liquid silicone rubber is a liquid polyorganosiloxane compound having a functional group capable of condensation reaction or addition reaction (reacting a silane compound having a functional group with a polyorganosiloxane compound having a hydroxy group such as dihydroxypolydimethylsilicone oil). Is used as a raw material. For this reason, the liquid silicone rubber is in a liquid state before being cured, but becomes a rubbery polymer or silicone rubber by being polymerized and cured at a functional group portion by moisture in the atmosphere or heating. Therefore, a type that undergoes a condensation reaction with moisture in the atmosphere in the curing reaction is classified as a condensation type, and a type that performs an addition reaction of an Si—H group to an unsaturated group in the presence of a platinum catalyst or the like. Also, depending on the packaging form, it is classified into a one-pack type that uses what is contained in the package as it is, and a multi-pack type that uses two or more components mixed immediately before use. Moreover, it is classified into room temperature curing type and heat curing type according to the curing temperature. Further, the condensed type is further subdivided by a gas generated during condensation due to a difference in functional group. For example, there are dealcoholization type, deketone type, and deacetic acid type.

  The liquid silicone rubber used as the sealing material of the present invention may be a condensation type or an addition type as long as the elastic modulus at 25 ° C. is 0.8 MPa or less at the time of curing. Are preferred. Condensation type liquid silicone rubber is a type that cures by hydrolysis condensation reaction with moisture in the air in the presence of a catalyst, etc., so it is a dehydrogenation type, dealcohol type, deacetic acid type among the compounds generated during the condensation reaction. , Deoxime type, deketone type, deamine type, deamid type, dehydroxyamine type, etc., but can be used as the sealing material of the present invention, except for deacetic acid type with metal corrosiveness . Furthermore, the liquid silicone rubber used as the sealing material of the present invention is not a two-component or more multi-component curable type having a pot life problem that must be prepared each time it is used, but a one-component curable type, particularly a one-component curable type. The condensed type is convenient and preferable. Here, as means for reducing the elastic modulus of the liquid silicone rubber at the time of curing, it is possible to roughen the crosslink density of the cured product or to add liquid silicone oil having no reactive functional group to the raw material. . However, in any case, when the crosslink density of the cured product becomes too coarse, or when the amount of liquid silicone oil added is large, the liquid silicone rubber becomes a so-called gel, and the surface adhesiveness is maintained even after curing. This is not preferable because it has a drawback that it easily adheres to other parts.

  According to the automobile harness with a terminal of the present invention, sufficient waterproofness can be exhibited even in a severe use environment.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. First, as a first embodiment of the present invention, a terminal-equipped automobile harness 1 having a waterproof structure in which conductors are filled with a sealing material shown in FIG. 1 will be described. As shown in FIGS. 1A and 1B, the terminal-equipped automobile harness 1 has a ground terminal 3 attached to the end of the ground wiring 2, and liquid silicone rubber is applied and cured to provide a sealing material 4. It has been. At this time, the terminal-equipped automobile harness 1 before applying the liquid silicone rubber is shown in FIGS.

  In the ground wiring 2, a conductor 2 a made of a stranded wire is covered with an insulating coating 2 b such as PVC or polyolefin. As shown in FIG. 3, the ground terminal 3 includes a fixed plate 3a at one end, a wire barrel 3b that grips the conductor 2a at the other end, and an insulation barrel 3c that grips the ground wiring 2 at a portion of the insulating coating 2b. Is a round plate terminal for automobile (JIS D 5403) in which a mounting plate is provided with a mounting hole 3d.

  The sealing material 4 is a one-part curable liquid silicone rubber having an elastic modulus at 25 ° C. of 0.8 MPa or less at the time of curing, and the conductor 2a and the insulating coating 2b are provided between the wire barrel 3b and the insulation barrel 3c. It is applied and cured so as to cover continuously. At this time, the sealing material 4 penetrates into the conductor 2a and reaches the ground terminal 3 side, and is bonded not only to the conductor 2a but also to the insulating coating 2b and the ground terminal 3.

  Here, applying the liquid silicone rubber over a wide range of the ground wiring 2 and the ground terminal 3 does not hinder the effect of watertight sealing, and is good in terms of sealing properties. However, for the purpose of the present invention, as described above, the sealing material 4 is applied between the wire barrel 3b and the insulation barrel 3c so as to continuously cover the conductor 2a and the insulating coating 2b. If it is, it will be effective enough.

  In addition, it is preferable to use a dispenser (an apparatus that controls the discharge amount by air pressure and time) because the discharge amount of the liquid silicone rubber can be given quantitativeness. Since the automobile harness 1 with a terminal has a waterproof structure as described above, the exposed conductor 2a and the insulating coating 2b are sealed between the exposed conductor 2a and the insulating coating 2b in a watertight manner. Water will not enter.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The automobile harness 10 having a waterproof structure shown in FIG. 4 has a concentrated joint portion 10a formed by bundling three conductors 11a at the end of the ground wiring 11. The concentrated joint portion 10a is a portion for connecting the three ground wirings 11 to other electrical connection bodies in a lump. The conductor 11a exposed by removing the insulating coating 11b from the ground wiring 11 is, for example, ultrasonic welded. As shown in FIG. 5, a plurality of parts are integrated by electrical welding or the like. As shown in FIG. 4, the concentrated joint portion 10a is covered with a sealing material 12 provided by applying and curing liquid silicone rubber so as to continuously cover the entire conductor 11a from the insulating coating 11b of the ground wiring 11. Has been.

  As the sealing material 12, a one-part curable liquid silicone rubber having an elastic modulus at 25 ° C. of 0.8 MPa or less at the time of curing is used. This liquid silicone rubber can be applied, for example, by immersing the concentrated joint portion 10a in the liquid silicone rubber, or can be applied by a normal application means. To penetrate.

  Since the automobile harness 10 having a waterproof structure in which the conductors are filled with the sealing material of the present embodiment is formed as described above, the liquid silicone rubber is cured between the exposed conductor 11a and the insulating coating 11b. It is sealed watertight by the provided sealing material 12 so that water does not enter from the end of the ground wiring 11. Here, after applying the liquid silicone rubber, the automobile harness 10 is covered with a cap 13 as shown in FIG. 6, or a plurality of conductors 11a are integrated in a cap previously filled with the liquid silicone rubber, as shown in FIG. The concentrated joint portion 10a shown may be dipped and cured. If it does in this way, dirt of concentration joint part 10a can be prevented until liquid silicone rubber hardens.

  20 automotive harnesses with terminals 1 adopting the waterproof structure shown in FIG. 1 were prepared for each example and comparative example, and the waterproof property based on the temperature cycle test was evaluated. Here, Example 1 is a type in which methanol is generated during a condensation curing reaction as a liquid silicone rubber forming a sealing material, and a one-part curable liquid silicone rubber having an elastic modulus at 25 ° C. of 0.68 MPa at the time of curing. Using.

  Example 2 is a type that similarly generates methanol during the condensation curing reaction, and a one-part curable liquid silicone rubber having an elastic modulus at 25 ° C. of 0.55 MPa at the time of curing is used.

  On the other hand, Comparative Example 1 is a type that generates methanol during the condensation curing reaction, and a one-part curable liquid silicone rubber having an elastic modulus of 0.93 MPa at 25 ° C. was used during the curing. In the temperature cycle test, the terminal-equipped automobile harness 1 was raised from room temperature to 120 ° C., left at this temperature for 1 hour, cooled to −40 ° C., left for 1 hour, and then raised to 120 ° C. again. With this as one cycle, the temperature of 1000 cycles was changed.

  Before and after the temperature cycle test, nitrogen gas whose pressure was adjusted to 0.098 MPa was sent from one end of the terminal-equipped automobile harness 1 to be inspected for 5 minutes, and the seal member 4 side at the other end was immersed in water to check for leaks. Was evaluated for waterproofness. The results are shown in Table 1. As is clear from Table 1, the automobile harness with a terminal of Comparative Example 1 in which the sealing material is formed of a liquid silicone rubber having an elastic modulus exceeding 0.8 MPa specified in the present invention is airtight after the temperature cycle test. Therefore, the waterproofness was lost. On the other hand, the automobile harness with a terminal of Examples 1 and 2 in which the sealing material is formed of the liquid silicone rubber having the elastic modulus defined in the present invention has good adhesion of the sealing material, before and after the temperature cycle test. It has been found that it has airtightness and therefore waterproofness and has excellent watertightness.

  Comparative Example 2 is an automobile harness 10 having the structure shown in FIG. 4 in which methanol is generated at the time of condensation curing reaction, and a one-part curable liquid silicone rubber having an elastic modulus at 25 ° C. of 0.93 MPa is applied at the time of curing. Example 3 shows a waterproof property before and after the temperature cycle test, in which acetone is generated at the time of the condensation curing reaction, and at the time of curing, a one-part curable liquid silicone rubber having an elastic modulus at 25 ° C. of 0.72 MPa is applied. And evaluated in the same manner as in Examples 1 and 2 and Comparative Example 1.

  Furthermore, this is a type that generates methanol at the time of condensation curing reaction, and at the time of curing, a one-part curable liquid silicone rubber having an elastic modulus at 25 ° C. of 0.55 MPa was applied as Example 4, and Examples 1 and 2 were compared. Evaluation was performed in the same manner as in Example 1.

  The results are shown in Table 2. As is apparent from Table 2, the waterproof structure of the automobile harness in which the sealing material is formed of the liquid silicone rubber satisfying the elastic modulus defined in the present invention has good adhesion of the sealing material and is excellent before and after the temperature cycle test. It was found to have water tightness.

  According to the first aspect of the present invention, the gap between the conductors is surely filled with the sealing material, and the sealing material capable of exhibiting sufficient waterproofness even in a harsh use environment by improving the adhesion of the sealing material. The automobile harness with a terminal which has the waterproof structure which filled the space | interval can be provided. According to the second and third aspects of the invention, the advantages of the automobile harness provided with the waterproof structure of the present invention can be maximized.

  According to invention of Claim 4, it is excellent in the usability of a sealing material and can be handled easily.

It is the front view (a) and side view (b) which show 1st Embodiment which concerns on the motor vehicle harness with a terminal of this invention. It is the front view (a) and the side view (b) before forming a sealing material in the automobile harness with a terminal of FIG. It is a perspective view which shows the state which attaches a terminal to earth wiring in the motor vehicle harness with a terminal of FIG. It is the front view which showed partially 2nd Embodiment which concerns on the motor vehicle harness with a terminal of this invention in the cross section. It is a front view before forming a sealing material in the automobile harness with a terminal of FIG. It is the front view which showed the modification of the motor vehicle harness with a terminal of FIG. 4 in the cross section partially.

Explanation of symbols

1 Automotive harness with terminal 2 Ground wiring 2a Conductor 2b Insulation coating 3 Ground terminal 3a Fixing plate 3b Wire barrel 3c Insulation barrel 3d Mounting hole 4 Sealing material (silicone rubber)
DESCRIPTION OF SYMBOLS 10 Automobile harness 10a Concentration joint part 11 Ground wiring 11a Conductor 11b Insulation coating 12 Seal material (silicone rubber)
13 cap

Claims (5)

A terminal-equipped automobile harness having a waterproof structure in which the conductors are filled with a sealing material
(A) an automobile harness comprising a conductor and an insulation coating;
(B) The conductor portion and the insulation coating portion exposed by removing the insulation coating from the automobile harness were respectively attached to the conductor portion and the insulation coating portion by gripping with the wire barrel and the insulation barrel. A terminal with the wire barrel and the insulation barrel;
(C) comprising the sealing material,
(I) The above-mentioned sealing material is a solvent-free type one-component curing type having an elastic modulus at 25 ° C. in the range of 0.55 to 0.8 MPa, and deacetication in a classification based on a compound generated during the condensation reaction. Consists of condensation type liquid silicone rubber excluding type,
(Ii) The terminal-equipped automobile harness, wherein the sealing material is provided so as to continuously cover the conductor and the insulating coating between the wire barrel and the insulation barrel.   The terminal-equipped automobile harness according to claim 1, wherein the terminal is a ground terminal. It is an automobile harness with a terminal having a waterproof structure in which a gap between conductors is filled with a sealing material,
(A) a plurality of automobile harnesses made of a conductor and an insulation coating;
(B) a concentration joint portion in which a plurality of conductor portions exposed by removing the insulation coating from the plurality of automobile harnesses are bundled;
(C) comprising the sealing material,
(I) The above-mentioned sealing material is a solvent-free type one-component curing type having an elastic modulus at 25 ° C. in the range of 0.55 to 0.8 MPa, and deacetication in a classification based on a compound generated during the condensation reaction. Consists of condensation type liquid silicone rubber excluding type,
(Ii) The terminal-equipped automobile harness, wherein the sealing material is provided so as to continuously cover the conductor and the insulating coating.   The sealing material is a dehydrogenation type, a dealcohol type, a deoxime type, a deketone type, a deamine type, a deamid type, or a dehydroxyamine type in classification by a compound generated during a condensation reaction. The terminal-equipped automobile harness according to any one of claims 1 to 3.   The terminal-equipped automobile harness according to claim 1, wherein the elastic coefficient is 0.55 to 0.72 MPa.