JPH0562143U - Sealing structure at the cable end for electrical components - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a structure of a cable for electrical components which is excellent in airtightness and watertightness only by performing a simple process. In a cable for electrical components, in which a sheath is continuously coated around a plurality of conductors along the longitudinal direction of the conductors, the conductors exposed from the sheath are separated from each other and the sheath of the cable end is A sealing structure for a cable end for an electrical component, characterized in that a part of a grommet that continuously covers the outer periphery and the peripheral surface of the conductor exposed from the sheath seals over the entire peripheral surface of each conductor.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the structure of a twisted cable end used as a power transmission line for various electrical components.

[0002]

[Prior Art]

 Known are an anti-lock brake system (ABS), a traction control system (TCS), and the like, which controls brake fluid pressure based on wheel information to prevent wheel lock and drive wheel slip. In this type of system, wheel information is obtained by using a vehicle wheel speed sensor a fixed on the vehicle body side and a gear-shaped rotor b mounted on the wheel side, as shown in FIG. The wheel speed sensor a is composed of a permanent magnet c, a pole piece d, a solenoid coil e, and a housing f, and extracts an AC voltage induced in proportion to the rotation of the rotor b. The change in voltage detected by the wheel speed sensor a is sent to an electronic control circuit (not shown) through a cable g connected to each end of the solenoid coil e in the wheel speed sensor a, and is calculated as the wheel rotation speed. .. By the way, in the case of the electric component exposed to the outside as in the case of the wheel speed sensor a, it is important to sufficiently perform the airtight treatment so that water does not enter from the connecting portion between the cable g and the electric component. In particular, the housing f of the wheel speed sensor a is made of a hard resin, and the sheath h covering the outermost part of the cable g is made of a soft resin. When both g and h are directly connected, a combination of different members is formed. A gap due to the difference in temperature shrinkage is likely to occur at the connecting portion of h. Therefore, conventionally, the housing f of the wheel speed sensor a and the sheath h are connected to each other with a resin-made grommet i having an intermediate hardness and having an uneven outer periphery.

[0003]

[Problems to be solved by the device]

 The above-described conventional connection structure for electrical components and cables has the following problems.

<A> The cable g is manufactured by coating a sheath h on the outer circumferences of two conductive wires j and j with an insulating coating that are spirally twisted as shown in an enlarged view in FIG. However, since the cable g is manufactured by injection molding, there is a limit to bringing the sheath h into close contact with the entire circumferential surface of the conductor wire j, and a gap k 2 is likely to occur at the abutting position of both conductor wires j, j. Therefore, the generation of the continuous voids k causes the reliability of the airtightness and watertightness of the cable g to be low.

<B> In the case of the wheel speed sensor a, the connector side (not shown) of the cable is opened to the atmosphere, and the pressure inside the wheel speed sensor a fluctuates with the temperature change. Water is allowed to enter the wheel speed sensor a through the gap k. As a result, the insulation resistance of the sensor decreases significantly, and if the function deteriorates, the wheel speed cannot be measured.

[0006]

[Purpose of the present invention]

 The present invention has been made to solve the above problems, and an object thereof is to provide a structure of a cable for electrical components which is excellent in airtightness and watertightness only by performing simple processing. Especially.

[0007]

[Means for solving problems]

 The present invention relates to a cable for electrical components in which a sheath is continuously coated around a plurality of conductors along the longitudinal direction of the conductors, and the conductors exposed from the sheath are separated from each other, and the sheath at the cable end is separated from each other. This is a sealing structure for the cable end for electrical components, characterized in that a part of the grommet that continuously covers the outer circumference of the conductor and the peripheral surface of the conductor exposed from the sheath seals over the entire peripheral surface of each conductor. ..

[0008]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

<A> Wheel Speed Sensor FIG. 1 shows a connection structure of a wheel speed sensor 1 and a cable 2 which are an example of electrical components. The wheel speed sensor 1 is a known electromagnetic induction type sensor. The cable 2 is a well-known twisted cable composed of two conducting wires 22 and 22 with an insulating coating 21 that are spirally twisted at a constant pitch, and a sheath 23 that covers the outer circumference of these conducting wires 22 and 22. Each of the conductors 22, 22 of the cable 2 is connected to a solenoid coil in the wheel speed sensor 1. The insulating coating 21 is, for example, polyurethane resin (PUR), the sheath 23 is crosslinked polyethylene (PE), and the housing 11 of the wheel speed sensor 1 is made of polyamide (containing 66 nylon glass). The present invention is similar to the conventional one in that the housing 11 of the wheel speed sensor 1 and the cable 2 are connected via the grommet 3, but the treatment structure of the end portion of the cable 2 using the grommet 3 is different from the conventional one.

<B> Treatment Structure of Cable End Since the cable 2 is a known cable, a slight continuous void is generated between the peripheral surfaces of the conductors 22, 22 as described above. Therefore, in the present invention, the grommet 3 is integrally molded in a state in which the conductors 22, 22 at the ends of the cable 2 are separated from each other, and the grommet 3 seals the entire peripheral surfaces of the conductors 22, 22. That is, as shown in FIG. 2, the ends of the respective conductors 22 and 22 constituting the cable 2 are exposed from the terminal end of the sheath 23 by a certain length, and the cable 2 is placed in the mold 4 for molding the grommet 3. To accommodate the end of. Of course, the shape of the grommet 3 to be molded is concavely formed on the inner peripheral surface of the mold 4, and the conductors 22 and 22 are inserted in a state in which they are separated from each other on one side surface 2 One small hole is opened, and one hole for inserting the sheath 23 of the cable 2 is opened on the other side, and the mold 4 is a split mold because of the demolding relationship. There is. The end of the cable 2 is positioned in a hermetically sealed state in the form 4, and the material of the molten grommet 3 such as polyurethane resin (PUR) is injected from the inlet 41 of the form 4 at about 30 to 60 atm. Injection molding the grommet 3. The molten grommet 3 covers the entire peripheral surface of the sheath 23 and forms the corrugated portion 31 on the outer peripheral surface thereof. Further, as shown in FIG. 3, the conductors 22 exposed from the sheath 23 and separated from each other are covered over the entire circumferential surface of the conductors 22 to form the tip covering portion 32. That is, instead of the sheath 23, the tip end covering portion 32 of the grommet 3 covers the outer circumferences of the two conductive wires 22, 2. In particular, since the grommet 3 is injection-molded at a high pressure, the grommet 3 can cover the peripheral surface of each of the conductive wires 22 and 22 in a pressure-bonded state instead of simply covering the peripheral surface. After the grommet 3 is formed on one end of the cable 2 in this manner, the end of the cable 2 is housed in a mold for molding a wheel speed sensor (not shown) and integrated with the cable 2 as shown in FIG. The wheel speed sensor 1 is molded.

<C> Airtightness of Cable The airtightness of the connection portion of the cable 2 in FIG. 1 will be considered. Since the physical properties of the material of the grommet 3 (for example, heat resistance, expansion coefficient, hardness, etc.) are almost intermediate between the physical properties of the materials of the housing 11 and the sheath 23, the grommet 3 with the corrugated portion 3 1 is formed. Good airtightness can be maintained not only between the peripheral surface of the housing 11 and the peripheral surface of the grommet 3 and the sheath 23, respectively. Next, the water infiltration or air permeability from the free end side of the cable 2 will be examined. The connection end of the cable 2 connected to the wheel speed sensor 1 is covered by the tip covering portion 32 of the grommet 3 in close contact with the entire circumferential surface of each conductor wire 22 instead of the sheath 23. There is no gap between the conductor 22 and the grommet 3. Therefore, even if water or air passes through the cable 2 through the small space formed between the conductors 22 in the wheel speed sensor 1, the cable 2 is first blocked between the grommet 3 and the conductor 22 immediately after the end of the sheath 23. Further, since the tip covering portion 32 and the conducting wire 22 are shut off from each other, the passage of water and air can be surely blocked. Therefore, even if the free end of the cable 2 is arranged in the atmosphere and a negative pressure is generated in the wheel speed sensor 1 due to the temperature difference, there is no intention of flooding the wheel speed sensor 1 through the cable 1.

[0012]

Second Embodiment FIG. 4 shows another embodiment in which the tip of the cable 2 is cut off in a stepwise manner. In this embodiment, a cable in which the distal end of the sheath 23 is cut out with a constant width and a defective portion 24 is formed is integrally molded with the grommet 3. In the present embodiment, while having the blocking function of the first embodiment, a blocking function between the insulating coating 21 and the grommet 3 of each conductive wire 22 exposed in the defective portion 24 of the sheath 23 is added. The number of the defective portions 24 of the sheath 23 may be plural or more.

[0013]

Third Embodiment In addition to the structure of the end portion of the cable 2 of the second embodiment, FIG. 5 partially cuts the insulating coating film 21 of each conductor 22 exposed from the sheath 23 to form a cut portion 25. This is an example in which a blocking function between the bare wire exposed in the cutout portion 25 and the grommet 3 is added. The number of cutouts in the conductive wire 22 may be more than one.

[0014]

Fourth Embodiment Although the twisted cable in which the two conductors 22 are twisted has been described above, the present invention can be applied to the end treatment of a cable of the type in which the conductors 22 are arranged in parallel without twist. is there. Further, it is needless to say that the present invention can be applied to a cable having three or more conductors. Further, this seal structure may be adopted on the other end side or both sides of the cable 2.

[0015]

[Effect of the device]

 Since the present invention is as described above, the following effects can be obtained.

<B> Since some of the grommet, which has been used as a connecting member between different members having different hardness so far, is used as a seal member for a conductor wire that constitutes a cable, no member is added. The cable can be sealed to the.

<B> Since the conductors exposed from the sheath are separated from each other, and a part of the grommet can be adhered and covered over the entire circumferential surface of the conductor at the exposed conductor, the gap between the conductor and the grommet can be covered. Does not create voids. Moreover, since the grommet is pressure-molded, the grommet strongly press-bonds to the peripheral surface of the conductor wire, so that an extremely high sealing effect can be obtained.

<C> It can be applied to connection cables for various electrical components, and is highly versatile.

[Brief description of drawings]

FIG. 1 is a sectional view of a cable according to a first embodiment.

FIG. 2 is an explanatory diagram of a grommet molding method.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view of a cable according to a second embodiment.

FIG. 5 is a sectional view of a cable according to a third embodiment.

FIG. 6 is an explanatory diagram of a conventional technique.

FIG. 7 is an enlarged sectional view taken along line VII-VII in FIG.

Claims (3)

[Scope of utility model registration request] 1. A cable for electrical component, wherein a plurality of conductors are continuously covered with a sheath along a longitudinal direction of the conductors, wherein the conductors exposed from the sheath are separated from each other, and A seal structure for a cable end for an electrical component, wherein a part of a grommet that continuously covers the outer periphery of the sheath and the peripheral surface of the conductor exposed from the sheath seals over the entire peripheral surface of each conductor. 2. A cable for electrical component, wherein a sheath is continuously covered around a plurality of conductors along a longitudinal direction of the conductors, wherein a peripheral surface of the sheath is partially removed to expose the conductors between the sheaths. The outer peripheral surface of each conductor exposed between the sheaths is covered with a part of a grommet that continuously covers the outer periphery of the sheath at the cable end and the peripheral surface of the conductor exposed from the sheath. The seal structure at the cable end for electrical components described in. 3. A cable for electrical component, wherein a sheath is continuously coated around a plurality of conductors along the longitudinal direction of the conductors, wherein the conductors exposed from the sheath are separated from each other and the conductors are Part of the peripheral surface of the insulating coating that is formed is used to cover the peripheral surface of the conductor with a part of the grommet that continuously covers the outer periphery of the sheath at the cable end and the peripheral surface of the conductor exposed from the sheath. The seal structure for a cable end for an electrical component according to claim 1 or claim 2, characterized in that.