JP2011185294A - Seal member and seal structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit deterioration in sealing performance when external force such as torsion is applied to an electric wire. <P>SOLUTION: A cylindrical seal member 21 is inserted in an electric wire insertion hole 11 of a housing 7 having an electric wire 5 inserted therein and seals a gap between the outer peripheral face of the electric wire 5 and the inner peripheral face of the electric wire insertion hole 11. Sinusoidal wave-like mountains 33 and valleys 35 are formed on the inner and outer peripheral faces of the cylinder in the axial direction, and phases of the mountains 33 on one surface and the valleys 35 on the other surface are formed to match in the axial direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a seal member that seals a gap between an outer peripheral surface of an electric wire inserted into an insertion hole of a housing and an inner peripheral surface of the insertion hole, and a seal structure using the seal member.

  An electric device mounted on a vehicle or the like is covered with a housing in order to prevent leakage of liquid and gas and to block noise and vibration. This housing is provided with a connector insertion slot into which a connector for connecting an electric device to an external electric wire is inserted. The connector includes a housing having a through-hole into which the electric wire is inserted and an electric wire having a terminal connected to one end, and a gap between the outer peripheral surface of the electric wire and the inner peripheral surface of the through-hole of the housing is a cylindrical sealing member. A sealing structure for sealing is employed.

  In this type of seal structure, the seal member is housed in the insertion hole of the housing in a state in which the seal member formed of an elastic material is mounted on the outer peripheral surface of the jacket covering the electric wire. Yes. Here, the seal member is formed in a sine wave shape so that the outer peripheral surface and the inner peripheral surface repeat a mountain and valley in the axial direction, and a crest is formed on the inner peripheral surface on the back side of the outer peripheral surface. A trough is formed on the inner peripheral surface which is the back side of. For this reason, the seal member housed in the insertion hole of the housing is pressed against the inner peripheral surface of the insertion hole by the crest portion of the outer peripheral surface, so that the crest portion of the inner peripheral surface located on the back side of the seal member is Since the outer peripheral surface of the inner peripheral surface is pressed and the valley portion of the inner peripheral surface hardly presses the outer peripheral surface of the electric wire, uneven pressing force is generated in the axial direction.

  When such a seal member is installed in the insertion hole of the housing in a state where it is mounted on the electric wire, although the adhesion between the seal member and the electric wire is high, the strong pressing force from the crest portion of the seal member causes the electric wire to If the outer peripheral surface is pushed in by the seal member and remains depressed for a long time, the stress due to the recess is gradually relieved and may remain as a recess without returning elastically. When a depression is generated on the outer peripheral surface of the electric wire in this way, for example, when an external force such as torsion acts on the electric wire extending outside the housing and the electric wire in the housing is bent, the inner surface of the electric wire depression and the seal member There is a possibility that the contact position with the peripheral surface is deviated, and the pressing force by the seal member is lowered, leading to a decrease in sealing performance.

  On the other hand, for example, the inner peripheral surface of the cylindrical molded body is fixed to the outer peripheral surface of the electric wire inserted into the insertion hole of the housing with an adhesive, and a seal member is attached to the outer periphery of the fixed cylindrical molded body, A seal structure is disclosed in which a gap between the outer peripheral surface of the cylindrical molded body and the inner peripheral surface of the insertion hole of the housing is sealed by this seal member (see Patent Document 1).

  According to this structure, since the seal member is mounted on the outer periphery of the cylindrical molded body, the pressing force of the seal member does not act directly on the outer peripheral surface of the electric wire by acting on the cylindrical molded body. Even if a long time elapses, no depression is generated on the outer peripheral surface of the electric wire, and even when an external force such as torsion acts on the electric wire, a decrease in sealing performance can be suppressed.

JP 2002-324618 A

  However, according to the structure of Patent Document 1, since it is necessary to newly provide a cylindrical molded body between the seal member and the electric wire, the number of parts increases, and the cylindrical molded body is attached to the outer periphery of the electric wire. Since the process of adhering to the surface is required, the number of work steps increases, resulting in an increase in manufacturing cost.

  The present invention has been made in view of such a problem, and a seal capable of suppressing a decrease in sealing performance when an external force such as torsion acts on an electric wire without increasing the number of parts and the number of work steps. It is an object to provide a member and a seal structure.

  In order to solve the above problems, a sealing member of the present invention is a cylindrical sealing member that is inserted into an insertion hole of a housing in a state where an electric wire is inserted, and seals a gap between the outer peripheral surface of the electric wire and the inner peripheral surface of the insertion hole. The inner and outer peripheral surfaces of the cylinder are characterized in that sinusoidal peaks and valleys are formed in the axial direction, and the phases of the peaks on one surface and the valleys on the other surface are matched in the axial direction. .

  According to this, when the peak of the outer peripheral surface of the seal member is pressed against the inner peripheral surface of the insertion hole of the housing, the valley portion of the inner peripheral surface located on the back side of the peak is the largest in the axial direction. The stress acts in the direction of the electric wire, but this stress acts directly on the inner peripheral surface of the inner peripheral surface because the inner peripheral surface of the electric wire is pressed with the valley portion of the inner peripheral surface deformed. Compared with the case, the force which presses the outer peripheral surface of an electric wire can be made small. On the other hand, the smallest stress in the axial direction acts on the crest of the inner peripheral surface of the seal member in the electric wire direction, but this stress directly acts on the outer peripheral surface of the electric wire via the crest of the inner peripheral surface. Therefore, it is possible to increase the force for pressing the inner peripheral surface of the electric wire as compared with the case of acting on the valley portion of the inner peripheral surface. Thereby, since the force which the inner peripheral surface of a sealing member presses the outer peripheral surface of an electric wire is equalized in an axial direction, it can suppress that a hollow arises in the outer peripheral surface of an electric wire. As a result, even when torsion or the like occurs in the electric wire due to an external force, the adhesion between the inner peripheral surface of the sealing member and the outer peripheral surface of the electric wire can be maintained, and a decrease in sealing performance can be suppressed. Further, according to the present invention, it is only necessary to form the inner and outer peripheral surfaces of the sealing member in a predetermined shape, so that it is not necessary to increase the number of parts and the number of work steps, and the economy can be improved. it can.

  In this case, the seal member is formed so that the amplitude of the peaks and valleys formed on the inner peripheral surface of the cylinder and the amplitude of the peaks and valleys formed on the outer peripheral surface are the same. According to this, since the stress when the crest portion of the outer peripheral surface of the seal member is pressed against the inner peripheral surface of the insertion hole can be transmitted more uniformly in the axial direction to the inner peripheral surface, It can prevent more reliably that a dent arises in a surface.

  In order to solve the above-mentioned problem, the seal structure of the present invention opens an electric wire, a cylindrical seal member in which a through-hole into which the electric wire is inserted, and an insertion hole into which the seal member can be inserted. A seal structure in which a seal member seals a gap between the outer peripheral surface of the electric wire and the inner peripheral surface of the insertion hole, and a sinusoidal peak and valley are formed in the axial direction on the inner and outer peripheral surface of the seal member, It is characterized in that the phase of the crest on one surface and the trough on the other surface are matched in the axial direction.

It is sectional drawing which shows the whole structure of one Embodiment of the sealing structure using the sealing member to which this invention is applied. It is sectional drawing of one Embodiment of the sealing member to which this invention is applied. It is sectional drawing of one Embodiment of the conventional sealing member. It is a figure explaining the contact state of the outer peripheral surface of an electric wire when using the conventional seal member, and the inner peripheral surface of a seal member.

  Hereinafter, a seal member to which the present invention is applied and an embodiment of a seal structure using the seal member will be described with reference to FIGS.

  The seal structure of the present embodiment refers to a seal structure included in a connector for electrically connecting an electric wire to a terminal or the like to be connected. Specifically, a housing in which an electric device (not shown) is accommodated. In the connector attached to the connector insertion opening formed on the wall surface of the connector (the wall surface facing the terminal block), the gap between the outer peripheral surface of the electric wire inserted into the insertion hole of the housing of the connector and the inner peripheral surface of the insertion hole is sealed. A sealing structure that stops.

  Here, the electric device refers to a device for driving a machine, such as an electric motor mounted on a vehicle or the like. Here, the case means a metal container that accommodates electrical equipment or the like, but may be a housing that accommodates terminals, electrical equipment, or the like. An electric wire means a general structure formed by surrounding an outer periphery of a core wire with an insulating jacket, but it is composed of, for example, a core wire, an inner jacket, a braided wire, and a jacket like a coaxial cable. It may be done.

  The connector 1 of this embodiment is for electrically connecting an electric wire to a terminal block of an electric device via a terminal, and is formed of an insulating synthetic resin or the like. As shown in FIG. 1, the connector 1 includes a flange portion 3 that contacts the peripheral edge of the connector insertion port of the housing, and a cylindrical housing that extends from one surface of the flange portion 3 and through which the electric wire 5 is inserted. 7 and a cylindrical attachment portion 9 extending from the other surface of the flange portion 3 and through which the electric wire 5 is inserted. The attachment portion 9 has an outer shape that is fitted into the connector insertion port, and is formed to protrude from the flange portion 3 into a substantially U shape.

  Electric wire insertion holes 11 and 13 are formed in the housing 7 and the attachment portion 9, respectively. The electric wire insertion hole 11 of the housing 7 is coaxial with the electric wire insertion hole 13 of the attachment portion 9 and is formed larger than the diameter of the electric wire insertion hole 13. Below the wire insertion hole 13 of the attachment portion 9, a terminal hole 17 having a rectangular cross section into which one end side of the terminal 15 connected to the electric wire 5 is press-fitted is formed. The terminal 15 is formed by pressing a substantially rectangular flat plate having conductivity, and a screw hole connected to a terminal block of an electric device on the other end side opposite to the one end side press-fitted into the terminal hole 17. 19 is formed. A cylindrical sealing member 21 mounted on the outer periphery of the electric wire 5 is accommodated in the electric wire insertion hole 11 of the housing 7.

  The electric wire 5 is inserted into the electric wire insertion hole 11 of the housing 7 and the electric wire insertion hole 13 of the attachment portion 9, and one end side of the terminal 15 is press-fitted into the terminal hole 17 of the attachment portion 9. At the tip end side of the electric wire 5 inserted into the electric wire insertion holes 11 and 13, the core wire 23 exposed from the outer jacket is electrically connected to the terminal 15. In the electric wire 5 arranged in the electric wire insertion hole 11 of the housing 7, a gap between the outer peripheral surface and the inner peripheral surface of the electric wire insertion hole 11 is sealed with a seal member 21.

  The connector 1 configured in this manner is attached so that the flange portion 3 is in close contact with the housing in a state where the attachment portion 9 is fitted into the connector insertion port of the housing. Specifically, a screw hole (not shown) is formed in the flange portion 3, and a bolt inserted into the screw hole is screwed with a screw hole formed in the peripheral edge of the connector insertion port of the housing, whereby the connector 1. Is attached to the housing.

  Next, the seal member 21 which is a characteristic configuration of the present invention will be described in detail. The seal member 21 of the present embodiment is formed in a cylindrical shape using an elastic material such as rubber, and includes a main body portion 25 and an extending portion 27 in order from the insertion direction into the electric wire insertion hole 11. The axial length of the seal member 21 is formed longer than the axial length of the electric wire insertion hole 11. That is, of the both end faces in the axial direction of the seal member 21, the extending portion 27 extends outward from the opening of the wire insertion hole 11 in a state where the end face of the main body portion 25 is in contact with the back of the wire insertion hole 11. It has become. As shown in FIG. 2, the main body portion 25 has an inner diameter d1 that is equal to or slightly smaller than the outer diameter of the electric wire 5 and an outer diameter d2 that is equal to or slightly larger than the inner diameter of the electric wire insertion hole 11. When the electric wire is inserted into the electric wire insertion hole 11, the outer peripheral surface of the electric wire 5 and the inner peripheral surface of the electric wire insertion hole 11 are pressed against each other.

  The extending portion 27 has an inner diameter that is the same as the inner diameter d <b> 1 of the main body portion 25. On the inner periphery and the outer periphery of the end portion of the extending portion 27, annular projecting portions 29 and 31 are formed, respectively. The extending portion 27 is pressed when a cylindrical pressing member (not shown) is inserted into the electric wire insertion hole 11 from the rear of the sealing member 21 in a state where the sealing member 21 is accommodated in the electric wire insertion hole 11. It is located between the inner peripheral surface of the member and the outer peripheral surface of the electric wire 5. Here, the protruding portion 31 of the extending portion 27 is locked to the rear end portion of the pressing member, and the protruding portion 29 comes into contact with the outer peripheral surface of the electric wire 5.

  Next, the cross-sectional shape of the seal member will be described. As shown in FIG. 2, a crest 33 and a valley 35 are formed in a sinusoidal shape in the axial direction on the inner peripheral surface and the outer peripheral surface of the seal member 21, respectively, and the crest 33 on one surface and the trough 35 on the other surface are formed. The phases are matched in the axial direction. Here, the crest 33 means that the cross section of the inner peripheral surface or the outer peripheral surface is deformed in the direction in which the radial thickness is increased, and the valley 35 is in the direction in which the radial thickness is decreased. It means that the peripheral surface or the cross section of the outer peripheral surface is deformed. The inner peripheral surface and the outer peripheral surface of the seal member 21 are formed as continuous curved surfaces so that peaks 33 and valleys 35 appear alternately.

  The seal member 21 has valleys 35 formed on the inner peripheral surface located on the back side of the three peaks 33 on the outer peripheral surface, and peaks 33 formed on the inner peripheral surface located on the back side of the four valleys 35 on the outer peripheral surface. ing. The central position of the outer peripheral surface peak 33 and the central position of the inner peripheral surface valley 35, and the central position of the outer peripheral surface valley 35 and the central position of the inner peripheral surface peak 33 are respectively in the axial direction. The positions (phases) of are matched. Further, the amplitudes of the peaks 33 and valleys 35 formed on the inner peripheral surface of the seal member 21 and the amplitudes of the peaks 33 and valleys 35 formed on the outer peripheral surface are set to the same magnitude. The number of the crests 33 on the inner peripheral surface and the outer peripheral surface is not limited to this example, and can be set as appropriate according to the axial length of the seal member 21 and the like.

  Here, the operation of the seal member 21 of the present embodiment will be described in comparison with the operation of a conventional general seal member. As shown in FIG. 3, the conventional sealing member 37 has a crest 33 formed on the inner peripheral surface located on the back side of the crest 33 on the outer peripheral surface, and a trough 35 on the inner peripheral surface located on the back side of the trough 35 on the outer peripheral surface. Is formed. It is assumed that the outer diameter and inner diameter of the seal member 37 are formed to be the same size as the outer diameter and inner diameter of the seal member 21, respectively.

  When the sealing member 37 having such a structure is inserted into the electric wire insertion hole 11 of the housing 7, the outer peripheral surface of the sealing member 37 is compressed by pressing the portion of the crest 33 against the inner peripheral surface of the electric wire insertion hole 11. The stress generated inside the seal member 37 by compressing the seal member 37 in this way acts as F1 and F3 in the direction of pressing the crest 33 on the inner peripheral surface of the seal member 37 against the outer peripheral surface of the electric wire 5. At the same time, F2 acts in a direction in which the valley 35 on the inner peripheral surface of the seal member 37 is pressed against the outer peripheral surface of the electric wire 5.

  Here, the force of F1 and F3 is larger than the force of F2 because the crest 33 on the outer peripheral surface of the seal member 37 matches the direction compressed by being pressed against the inner peripheral surface of the wire insertion hole 11. It has become. In addition, the forces F1 and F3 directly act on the outer peripheral surface of the electric wire 5 via the crest 33 on the inner peripheral surface of the seal member 37. On the other hand, the force of F <b> 2 merely presses the valley 35 on the inner peripheral surface of the seal member 37, and usually does not reach the outer peripheral surface of the electric wire 5. For this reason, the force with which the seal member 37 presses the outer peripheral surface of the electric wire 5 is concentrated on the portion where the crest 33 on the inner peripheral surface of the seal member 37 abuts. Thus, since the outer peripheral surface of the electric wire 5 pressed against the crest 33 on the inner peripheral surface of the seal member 37 has elasticity, it is deformed inward, and if this state continues for a long time, the stress accompanying the deformation is increased. It is gradually relaxed and becomes a depression. The dent of the electric wire 5 does not easily return to the original state in a state where the stress is relaxed, and remains as a shape on the outer peripheral surface of the electric wire 5.

  Here, the influence which the hollow produced in the outer peripheral surface of this electric wire 5 has on sealing performance is demonstrated. In FIG. 4, when an external force such as torsion acts on the electric wire 5 extending outward from the electric wire insertion hole 11 of the housing 7, the electric wire 5 in the electric wire insertion hole 11 is bent in the direction of arrow A following this. It is a figure explaining the contact state of the outer peripheral surface of this electric wire 5, and the inner peripheral surface of the sealing member 37. FIG. Here, it is assumed that a depression 39 is formed on the outer peripheral surface of the electric wire 5 by being pressed against the crest 33 on the inner peripheral surface of the seal member 37 for a long time.

  Thus, when the electric wire 5 having the recess 39 formed on the outer peripheral surface is curved, the contact portion between the outer peripheral surface of the electric wire 5 and the inner peripheral surface of the seal member 37 is positioned at P2. That is, when the electric wire 5 is not curved, P1 which is the central portion of the crest 33 on the inner peripheral surface of the seal member 37 is in contact with the outer peripheral surface of the electric wire 5, but when the electric wire 5 is bent, the contact portion Is shifted from P1 to P2. Here, when the force that the inner peripheral surface of the seal member 37 presses the outer peripheral surface of the electric wire 5 at the contact portion P2 is F5 ′ and the radial component of the seal member 37 is F5, F5 ′ <F5 <F1. Since the force with which the seal member 37 presses the electric wire 5 is significantly reduced as compared with the state before the electric wire 5 is bent, the sealing performance is deteriorated.

  In contrast, in the seal member 21 of the present embodiment, as shown in FIG. 2, the stress generated by compressing the portion 33 of the outer peripheral surface pressed against the inner peripheral surface of the wire insertion hole 11 is F1 ′ acts to deform and press the valley 35 on the inner peripheral surface of the seal member 21 against the electric wire 5, and F2 ′ and F4 ′ denote the central portion of the crest 33 on the inner peripheral surface of the seal member 21 as the electric wire 5. F3 ′ acts in the direction in which the inclined surface of the crest 33 on the inner peripheral surface of the seal member 21 is deformed and pressed against the electric wire 5.

  Here, the largest F1 ′ force acts in the center of the valley 35 on the inner peripheral surface of the seal member 21, and this F1 ′ force is applied to the valley 35 on the inner peripheral surface of the seal member 21. Since the inner peripheral surface of the electric wire 5 is pressed in a deformed state, the force for pressing the inner peripheral surface of the electric wire 5 is smaller than when acting directly on the electric wire 5 via the mountain 33 on the inner peripheral surface of the seal member 21. . Further, the smallest force F2 ′, F4 ′ in the axial direction acts on the center of the crest 33 on the inner peripheral surface of the seal member 21, and the force F2 ′, F4 ′ acts on the crest 33 of the seal member 21. Since it acts directly on the outer peripheral surface of the electric wire 5 via the, the force pressing the inner peripheral surface of the electric wire 5 becomes larger than when acting on the valley 35 on the inner peripheral surface of the seal member 21. Thereby, since the force which the sealing member 21 presses the outer peripheral surface of the electric wire 5 is equalized in an axial direction, it can suppress that the dent 39 arises in the outer peripheral surface of the electric wire 5. FIG.

  By suppressing the generation of the recess 39 in this way, even when an external force acts on the electric wire 5 and the electric wire 5 in the electric wire insertion hole 11 is bent, the inner peripheral surface of the seal member 21 and the electric wire 5 are Since the contact point with the outer peripheral surface can be kept at P1 or in the vicinity thereof, the force of F1 or a force close to F1 can be applied to the outer peripheral surface of the electric wire 5. Therefore, the force with which the inner peripheral surface of the seal member 21 presses the outer peripheral surface of the electric wire 5 can be maintained in a high state, and a decrease in sealing performance when an external force such as torsion acts on the electric wire 5 can be suppressed. .

  In the present embodiment, the amplitude of the crest 33 and trough 35 on the inner peripheral surface of the seal member 21 and the amplitude of the crest 33 and trough 35 on the outer peripheral surface are the same. The stress caused by compressing the portion 33 of the outer peripheral surface pressed against the inner peripheral surface of the electric wire insertion hole 11 is made more uniform in the axial direction on the outer peripheral surface of the electric wire 5 via the inner peripheral surface of the seal member 21. Since it can transmit, it can prevent more reliably that the hollow 39 is produced in the outer peripheral surface of the electric wire 5. FIG.

  In the present embodiment, the crest 33 is formed on the inner peripheral surface of both ends (axial direction) of the main body portion 25 of the seal member 21, and the protrusion 29 is formed on the inner peripheral surface of one end of the extending portion 27. Therefore, even when the electric wire 5 is twisted or the like due to an external force and the electric wire 5 is bent, the state where the crest 33 and the protrusion 29 on the inner peripheral surface of the seal member 21 are in close contact with the outer peripheral surface of the electric wire 5 can be maintained. Therefore, it is possible to suppress a decrease in sealing performance.

  Further, in the present embodiment, since the crest 33 and the trough 35 formed on the inner peripheral surface and the outer peripheral surface of the seal member 21, particularly the inner peripheral surface, are formed by a continuous sinusoidal curved surface, for example, the trough portion is formed. Compared with the case of forming a plane parallel to the axis (see FIG. 3 of Japanese Utility Model Publication No. 5-84083), the pressing force pressing the outer peripheral surface of the electric wire 5 can be made more uniform in the axial direction. Thereby, since the generation | occurrence | production of the hollow in the outer peripheral surface of the electric wire 5 can be prevented more reliably, even when a twist etc. arise in the electric wire 5 by external force and the electric wire 5 curves, a sealing performance fall can be suppressed. .

  Note that, according to the seal structure of the present embodiment, the conventional seal member 37 is used in a state where the electric wire 5 is arranged straight in the electric wire insertion hole 11 and the outer peripheral surface of the electric wire 5 is not depressed. Compared with the conventional seal structure, the sealing performance of the gap between the outer peripheral surface of the electric wire 5 and the inner peripheral surface of the seal member may be reduced. However, with respect to this point, the desired sealing performance can be ensured by changing the axial length of the sealing member 21 and the like. Rather, the seal structure of this embodiment is advantageous in that it is possible to suppress a decrease in sealing performance when the electric wire 5 is curved in the electric wire insertion hole 11.

DESCRIPTION OF SYMBOLS 1 Connector 5 Electric wire 7 Housing 11, 13 Electric wire insertion hole 21 Seal member 25 Main-body part 27 Extension part 33 Mountain 35 Valley 39 Depression

Claims (3)

A cylindrical sealing member that is inserted into the insertion hole of the housing in a state where the electric wire is inserted, and seals a gap between the outer peripheral surface of the electric wire and the inner peripheral surface of the insertion hole,
A seal member in which sinusoidal peaks and valleys are formed in the axial direction on the inner and outer peripheral surfaces of a cylinder, and the phases of the peaks of one surface and the valleys of the other surface are matched in the axial direction.   2. The seal member according to claim 1, wherein the seal member is formed such that the amplitude of the peaks and valleys formed on the inner peripheral surface of the cylinder is the same as the amplitude of the peaks and valleys formed on the outer peripheral surface. An electric wire, a cylindrical seal member in which a through-hole into which the electric wire is inserted is formed, and a housing in which an insertion hole into which the seal member can be inserted is opened,
The seal structure seals the gap between the outer peripheral surface of the electric wire and the inner peripheral surface of the insertion hole,
A seal structure in which sinusoidal peaks and valleys are formed in the axial direction on the inner and outer peripheral surfaces of the seal member, and the phases of the peaks of one surface and the valleys of the other surface are matched in the axial direction.

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