cable entry

Abstract

Cable entry (G1, G2) configured to cover a pipe (1) in which a cable is inserted and a corrugated hose (5), wherein the cable entry (G1, G2) bridges the pipe (1) and the corrugated hose (5), the corrugated hose (5) forms a flexible bellows shape in which combs (5A) and troughs (5B) alternate, the cable emerging from an end section of the pipe (1) is received in the corrugated hose (5), and the cable entry (G1, G2) has the following features: a pipe-side end section (8) which is tubular in shape and can be sealed to an outer circumferential side of the pipe (1), a corrugated hose end section (9) which is tubular in shape and can be sealed to an outer circumferential side of the corrugated hose (5), and a plurality of sealing lips (14-1 ... 14-4; 20-1 ... 20-4) arranged on the respective inner surfaces of the corrugated hose end section (9) and the pipe end section (8) such that they are in close contact with an outer surface of the pipe (1) or the recesses (5B) of the corrugated hose (5), characterized in that: in the pipe-side end section (8) a first sealing lip (14-1), a second sealing lip (14-2) and a third sealing lip (14-3) are provided, the first sealing lip (14-1) and the third sealing lip (14-3) are arranged outside a width region to which the cable gland (G1, G2) can be attached with a fastening band (12) arranged on an outer surface of the pipe-side end section (8), and the second sealing lip (14-2) is provided between the first sealing lip (14-3) and the third sealing lip (14-3) within this latitudinal region.

Description

TECHNICAL FIELD

[0001] The present invention relates to a cable bushing. TECHNICAL BACKGROUND

[0002] Traditionally, in hybrid and electric cars, wiring is often implemented by routing a wire harness, for example, between the battery and the inverter, or between the inverter and the motor, within a metal conduit. The metal conduit is arranged longitudinally under the floor of the car body. The metal conduit serves to shield the cable and protect it from debris and the like. After the cable is inserted into the engine compartment, the metal conduit may be connected to the inverter, for example, via a metal braid. The metal braid, formed by braiding metal strands or threads into a mesh shape, is attached to cover one end of the metal conduit and is connected to the end by crimping it with a crimp ring.In addition, a waterproof cable grommet made of a rubber material may be installed at the connecting portion between the metal pipe and the metal braided portion (JP 2006-311699A: . Fig. 1).

[0003] JP 2006-311699A is an example of related prior art.

[0004] EP 1465309A2 discloses a system of joints for connecting protective elements for electrotechnical purposes, wherein each joint of the system comprises a body made of plastic material and a seal made of elastomer material or thermoplastic elastomer, wherein the body and the seal are integrated into each other by adhesion.

[0005] US 5516985A discloses a cable end cap comprising a tubular sleeve, closed at a front end and made of a thermoplastic material, and an elastomer sealing element with sealing lips. The sleeve and sealing element are tightly connected to each other by a mounting ring.

[0006] JP H08-75060A discloses a pipe joint consisting of a socket internally fitted into a corrugated pipe, a plug portion with which the internally fitted corrugated pipe is brought into contact, and a fitting portion internally fitted into a conduit stopped by the machine screw. A window is provided in the socket, and a leaf spring with a V-shaped pawl, which is attached to a bottom of the corrugated pipe from outside this window, is provided in an outer surface of the socket. Sealing in the screwless conduit can be achieved by arranging O-rings between the corrugated pipe and the socket, and between the conduit and the fitting portion.

[0007] DE 19949867 C1 discloses a sealing ring for a plastic pipe (corrugated pipe) provided with external corrugations, wherein the sealing ring can be received in a corrugation trough of the corrugated pipe, wherein the sealing ring is designed as a symmetrical sealing ring with a substantially disc-shaped main seal for sealing against a second pipe receiving the corrugated pipe and two lateral support bodies extending from a base body for contact with the corrugation flanks of the corrugated pipe. OVERVIEW OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] Meanwhile, it is conceivable that high-pressure washing water may also spray into a location where a cable grommet is installed. However, the conventional structure described above cannot satisfactorily handle such a situation, and there are concerns that the seal between the corrugated hose and the cable grommet, and between the pipe and the cable grommet, may deteriorate over time. MEANS FOR SOLVING THE TASK

[0009] The present invention has been made in view of the situation described above, and has as its object to provide a cable bushing that can achieve improved waterproof performance. EFFECT OF THE INVENTION

[0010] A cable bushing according to one aspect of the present invention is a cable bushing having the features of claim 1.

[0011] The sealing lips arranged within the width region of the fastening band are susceptible to deterioration due to the effect of the fastening band's fastening force and tend to decrease their sealing function over time. Nevertheless, the present invention can effectively maintain the sealing function over time because sealing lips are also arranged outside the width region of the fastening band, and these lips can function as reserve lips or supporting lips. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view showing an area around a portion where a cable grommet is mounted; Fig. 2 is a cross-sectional view of the cable gland; Fig. 3 is a cross-sectional view of the section in which the cable gland is mounted; and Fig. Figure 4 is a cross-sectional view showing a variant of the cable entry. EMBODIMENTS OF THE INVENTION

[0012] A preferred embodiment of the present invention will now be described.

[0013] 1. In the cable grommet according to the present invention, a tapered surface may be formed on a front end portion of the outer surface of at least the pipe-side end portion or both the pipe-side end portion and the corrugated tube-side end portion.

[0014] The cable grommet is mounted in a state where it straddles the opposite ends on the pipe side and the corrugated hose side. For example, assuming that high-pressure washing water is projected against the end surface of at least the pipe-side end portion or both the pipe-side end portion and the corrugated hose side end portion, a steeply or upright end surface is likely to absorb the pressure of the high-pressure washing water. Thus, there would be a possibility that the end surface portion would be lifted and washing water would penetrate into the cable grommet. In this regard, with the above-described arrangement, the pressure of the high-pressure washing water can be released along the slope of the sloped surface. Thus, lifting of the end surface portion can be effectively counteracted, thereby maintaining the sealing function of the cable grommet.

[0015] 2. Preferably, a portion on the inner surface of the corrugated hose-side end portion located within the width region fastened with the fastening band is provided with: the sealing lips and a counteracting receiving portion against which a projecting end surface of the ridges of the corrugated hose abuts, so as to counteract a collapse of the sealing lips.

[0016] With this arrangement, even if the fastening band securing the corrugated tube-side end portion of the cable grommet is overtightened, the fastening force is absorbed by the protruding end surface of the corrugated tube ridge, and therefore the sealing lips are not excessively compressed (collapsed). Accordingly, the sealing function of the sealing lips can be maintained. First embodiment

[0017] Next, the first embodiment of the grommet according to the present invention will be described with reference to the drawings. In the present embodiment, a grommet G1 is described, which is provided on the routing path of a wire harness WH that connects a battery mounted in a rear passenger compartment to an inverter mounted in an engine compartment in a hybrid vehicle.

[0018] As in Fig. As shown in Figure 1, the wire harness WH includes a plurality of wires. A portion of the wire harness WH is inserted into a shielding tube 1 made of a conductive metal. The shielding tube 1 is made of aluminum or an aluminum alloy and is arranged under the floor of the vehicle body. In addition, the front end of the shielding tube 1 is flared in a trumpet shape, forming a flared portion 2, as shown in Figure 1. Fig. 3 is shown.

[0019] One end of a metal braid section 3 is connected to an end portion of the shielding tube 1. The metal braid section 3 is formed by braiding, for example, copper-based metal strands with tinned surfaces into a net-like, elongated tube shape. The cables leading out of the shielding tube 1 are inserted into the metal braid section 3. The metal braid section 3 is attached to cover the outer surface of the shielding tube 1 and is crimped in place by a crimp ring 4.

[0020] The crimp ring 4 is a known crimp ring. In its natural or initial state, a portion of an annular main portion 4A of the crimp ring 4 is radially expanded outward and protrudes as a crimp portion 4B. At the time of fastening the crimp ring 4, the main portion 4A can be reduced in diameter by compressing or pinching the base portions of the crimp portion 4B to bring them closer together, thereby firmly crimping the metal braid portion 3 to the shielding tube 1.

[0021] The metal braided section 3 is inserted into the corrugated hose 5, except for a portion of its surface on the side connected to the shielding tube 1, and an end portion of the metal braided section 3 extends to the connection with an inverter (not shown). In this way, the shielding properties of the wire harness WH are ensured along the section where the shielding tube 1 and the metal braided section 3 are provided.

[0022] The corrugated hose 5 is formed from a synthetic resin material as a one-piece, elongated hose. The peripheral surface of the corrugated hose 5 is formed in a bellows shape, in which a sequence of ridges 5A and troughs 5B repeats, and exhibits high flexibility. The cable gland G1, in which the part of the metal braid section 3 exposed outside the corrugated hose 5 is housed, is mounted between the corrugated hose 5 and the shielding tube 1 and bridges the distance between the corrugated hose 5 and the shielding tube 1.

[0023] The cable grommet G1 is formed from a rubber material (e.g., EPDM) as a one-piece body. The axially central portion of the cable grommet G1 serves as the base portion 6, and a housing portion 7 is formed in a part of the base portion 6, which bulges radially outward over a predetermined length in the circumferential direction. The interior of the housing portion 7 is the space in which the crimp portion 4B of the crimp ring 4 is housed.

[0024] A pipe-side end portion 8 is formed at one end of the cable grommet G1, and a corrugated tube-side end portion 9 is formed at the other end. Both the pipe-side end portion 8 and the corrugated tube-side end portion 9 are cylindrical. The pipe-side end portion 8 allows insertion of an end portion of the shielding tube 1, and the corrugated tube-side end portion 9 can be installed around the outer peripheral side of the corrugated tube 5.

[0025] Two annular projections 10 are formed around the entire circumference of the outer surface of the pipe-side end section 8, spaced apart from one another at positions in the region of the end section. The section between the two projections 10 serves as an attachment groove 11 for positioning a cable tie or fastening strap 12. It should be noted that the width of the attachment groove 11 is selected to be slightly wider than the width of the fastening strap 12.

[0026] Since the fastening band 12 is a known fastening band, it will only be briefly described here. The fastening band 12 is formed from a synthetic resin material as a one-piece and band-shaped body. At one end portion of the fastening band 12, a locking portion 13 is formed, which allows the other end of the fastening band 12 to be inserted. At the other end, a large number of serrated locking edges (not shown) are formed in the longitudinal direction. In addition, a flexible locking pawl (not shown) is formed inside the locking portion 13. By pulling the other end passed through the locking portion 13, which causes the pawl to be selectively locked with the locking edges, the pipe-side end portion 8 can be tied and fixedly attached to the umbrella pipe 1.

[0027] On the other hand, as in Fig. 2, on the inner surface of the tube-side end section 8 a plurality of (four in Fig. 2) Pipe-side sealing lips 14-1 to 14-4 are provided. The pipe-side sealing lips 14-1 to 14-4 are integrally formed and protrude around the entire circumference, and each of them can be in close contact with the outer surface of the shield pipe 1 to provide a seal. In the present embodiment, the tube-side sealing lips 14-1 to 14-4 include a lip provided at the opening edge of the tube-side end portion 8 (first lip 14-1), a lip provided at a portion directly below the center (with respect to the axial direction) of the attachment groove 11 (second lip 14-2), a lip provided at a portion slightly offset inward from a portion directly below the projection 10 further away from the opening edge (third lip 14-3), and a lip provided at a portion further offset inward from the third lip 14-3 (fourth lip 14-4).Thus, in the present embodiment, only the second lip 14-2 is located in a width region (the region within the width region shown in . Fig. 3, which is secured with the fastening band 12, and the other lips are arranged such that they are spaced from the width region and function as reserve lips or supporting lips. Furthermore, the projecting heights of the pipe-side sealing lips 14-1 to 14-4 are all designed the same.

[0028] Additionally, a tube-side tapered surface 15 is formed on the front end of the outer surface of the tube-side end portion 8. That is, an annular upright surface 18 is formed on the end surface of the tube-side end portion 8, which is erected at a substantially right angle to the axis. Furthermore, the above-described tube-side tapered surface 15 is formed around the entire circumference and extends from the outer peripheral edge of the upright surface 18 to the tip of the protrusion 10 on the front end side.

[0029] On the other hand, a recessed mounting groove 16 for positioning a cable tie or fastening band 12 extends around the entire circumference of the axially central portion on the outer surface of the corrugated tube-side end portion 9. Furthermore, a corrugated tube-side tapered surface 17 is formed at the front end of the outer surface of the corrugated tube-side end portion 9. That is, an annular upright surface 19 is formed on the end surface of the corrugated tube-side end portion 9, which is upright at a substantially right angle to the axis. Furthermore, the above-described corrugated tube-side tapered surface 17 is formed around the entire circumference from the outer peripheral edge of the upright surface 19 at a predetermined inclination angle.It should be noted that in the present embodiment, the inclination angle α1 of the tube-side tapered surface 15 is selected to be smaller than the inclination angle α2 of the corrugated tube-side tapered surface 17 (α1 < α2).

[0030] As in Fig. As shown in Figure 2, a plurality of corrugated-hose-side sealing lips 20-1 to 20-4 are provided on the inner surface of the corrugated-hose-side end portion 9. The corrugated-hose-side sealing lips 20-1 to 20-4 are provided at equal intervals from the sealing lip at the opening edge of the corrugated-hose-side end portion 9 toward the inside. This spacing is the same as that of the ridges 5A and troughs 5B of the corrugated hose 5. The protruding height of the corrugated-hose-side sealing lips 20-1 to 20-4 is selected to be higher than that of the tube-side sealing lips 14-1 to 14-4. In a state in which the end portion of the corrugated hose 5 is inserted into the corrugated hose-side end portion 9, the projecting end portions of the corrugated hose-side sealing lips are in close contact with the bottom surfaces of the troughs 5B of the corrugated hose 5 to thereby provide a seal.

[0031] Of the corrugated tube-side sealing lips 20-1 to 20-4, the two sealing lips (20-2, 20-3) arranged in the center are positioned such that they lie at least partially within the width region of the fastening band 12, which securely fastens the corrugated tube-side end section 9 in the mounting groove 16, whereas the corrugated tube-side sealing lip 20-1 provided at the opening edge and the corrugated tube-side sealing lip 20-4 provided in the innermost section are both positioned outside the width region W and function as reserve lips or supporting lips.

[0032] Furthermore, one of the ridges 5A of the corrugated hose 5 is arranged within the width region W of the fastening band 12 in the corrugated hose-side end portion 9. In Fig. 3, the ridge 5A is positioned substantially directly below the fastening band 12, and the ridge 5A abuts the portion of the inner surface of the corrugated tube-side end portion 9 that is located between the two corrugated tube-side sealing lips 20-2 and 20-3 within the width region W. Thus, this portion can function as a counteracting receiving portion 21, which prevents excessive compression (collapse) of the corrugated tube-side sealing lips 20-1 to 20-4 within the width region in the event of excessive tightening of the fastening band 12.

[0033] In the present first embodiment, the cable grommet G1 is installed, for example, in the following manner. First, a part of the metal braided portion 3 inserted into the corrugated tube 5 is pulled outward and attached to cover the outer surface of one end portion of the shielding tube 1. Then, the crimp ring 4, previously attached to the side of the shielding tube 1, is slid onto the covered portion. By crimping the crimp portion 4B of the crimp ring 4 in this state, the metal braided portion 3 is firmly crimped to the shielding tube 1.

[0034] Next, the grommet G1, which has been previously attached to the shielding pipe 1 side or the corrugated hose 5 side, is pushed toward the crimped portion of the metal braided portion 3. While the crimping portion 4B of the crimp ring 4 is accommodated in the accommodation portion 7 of the grommet G1, the corrugated hose-side end portion 9 is attached so as to cover the outer peripheral side of the end portion of the corrugated hose 5, and the pipe-side end portion 8 is attached so as to cover the outer peripheral side of the shielding pipe 1. In this way, the grommet G1 is attached so as to straddle the shielding pipe 1 and the corrugated hose 5.

[0035] Now, in the pipe-side end section 8, the pipe-side sealing lips 14-1 to 14-4 are in close contact with the outer surface of the shielding tube 1, and in the corrugated hose-side end section 9, the corrugated hose-side sealing lips 20-1 to 20-4 enter the corresponding troughs 5B of the corrugated hose 5 and are in close contact with the respective bottom surfaces.

[0036] Finally, the fastening band 12 is fastened in the mounting groove 11 in the pipe-side end section 8, and the fastening band 12 is fastened in the mounting groove 16 in the corrugated hose-side end section 9. This completes the installation of the cable entry G1.

[0037] With the cable gland G1 installed in the manner described above, it is possible to prevent water from entering between the cable gland G1 and the shielding pipe 1 or between the cable gland G1 and the corrugated hose 5 by using the pipe-side sealing lips 14-1 to 14-4 and the corrugated hose-side sealing lips 20-1 to 20-4.

[0038] In the tube-side end portion 8 and the corrugated hose-side end portion 9, the tube-side sealing lip 14-2 and the corrugated hose-side sealing lips 20-2 and 20-3 are located within the width regions W of the fastening bands 12 and directly below them, respectively. Accordingly, as long as the fastening bands 12 are properly fastened, an appropriate sealing pressure can be applied to the tube-side sealing lip 14-2 and the corrugated hose-side sealing lips 20-2 and 20-3. Even if the fastening band 12 on the corrugated hose 5 side is excessively tightened, the ridge 5A of the corrugated hose 5 is located directly below the fastening band 12 and abuts the opposing receiving portion 21. Thus, the corrugated hose-side sealing lips 20-2 and 20-3 are not excessively compressed, and the sealing properties are ensured.

[0039] Since the fastening bands 12 constantly exert pressure on the pipe-side sealing lip 14-2 and the corrugated-hose-side sealing lips 20-2 and 20-3 within the width regions of the fastening bands 12, it is conceivable that the respective sealing lips deteriorate over time, resulting in a deterioration in their sealing function. However, in the present embodiment, the pipe-side sealing lips 14-1, 14-3, and 14-4 and the corrugated-hose-side sealing lips 20-1 and 20-4 are further arranged outside the width regions W of the respective fastening bands 12 and enclose these width regions W from both sides. These lips outside the width regions W deteriorate very slowly over time and can therefore effectively maintain the sealing properties over a long period of time.In particular, it is of great importance that this structure is provided in the pipe-side end section 8 against which high-pressure washing water is likely to be sprayed.

[0040] From the sealing performance perspective, the most critical situation is where high-pressure washing water is sprayed onto the end face of the tube-side end portion 8 (it is also possible that washing water is sprayed onto the end face of the corrugated-tube-side end portion 9). Conventionally, this end face has a large upright surface perpendicular to the axis, and therefore, there is a possibility that the end face is lifted and water may intrude. In the present embodiment, however, by providing the corrugated-tube-side tapered surface 17 and the tube-side tapered surface 15, the area of ​​the upright surfaces 18 and 19 is significantly reduced compared to the corresponding areas in the conventional arrangement.The pressure of the high-pressure washing water is released along the two beveled surfaces 15 and 17, so that there are fewer situations in which the end surfaces of the two end sections 8 and 9 of the cable gland G1 can be lifted, and the sealing properties are reliably maintained.

[0041] Furthermore, since the corrugated tube-side sealing lips 20-1 to 20-4 formed at the opening edge enter the troughs 5B of the corrugated tube 5 in the corrugated tube-side end portion 9, this also counteracts any possible lifting of the end surfaces. In view of this, in the present embodiment, lifting does not occur even if the inclination angle α2 of the corrugated tube-side tapered surface 17 is set larger than the inclination angle α1 of the tube-side tapered surface 15. Accordingly, the thickness of the corrugated tube-side end portion 9 can be increased further than that of the tube-side end portion 8. The corrugated tube 5 side is the side on which the cable routing direction can be appropriately changed.Accordingly, for the purpose of ensuring traceability up to the corrugated hose 5, it is useful that a certain amount of thickness is ensured for the corrugated hose-side end portion 9 at the time of changing the guide direction in order to be able to increase the rigidity.

[0042] Conventionally, the corrugated tube-side end portion 9 is connected to the corrugated tube 5 by tape wrapping without using the fastening tape 12. However, it has been mentioned that such tape wrapping results in a less reliable connection due to operational fluctuations. When fastening is performed using the fastening tape 12 as in the present embodiment, a constant fastening force can be relatively easily maintained using a tensioning device or the like, thus achieving a more reliable connection. Furthermore, tape wrapping may lead to the problem of deterioration of the tape over time, but the present invention does not have such a problem.

[0043] Fig. 4 shows a variant of the corrugated hose-side sealing lips 20-1 to 20-4 and the pipe-side sealing lips 14-1 to 14-4. For a cable entry G2 as in Fig.As shown in FIG. 4, among the convoluted-tube-side sealing lips 20-1 to 20-4 and the tube-side sealing lips 14-1 to 14-4, the tube-side sealing lip 14-1 and the convoluted-tube-side sealing lip 20-1 located at the opening edges are selected to have a higher protruding height than the other sealing lips. This is to cope with the fact that the entire opening edges of the tube-side end portion 8 and the convoluted-tube-side end portion 9 may tend to widen when the fastening bands 12 are tightened, which may reduce the sealing functions of the convoluted-tube-side sealing lip 20-1 and the tube-side sealing lip 14-1 located at the opening edges.

[0044] This can also contribute to improving the sealing properties of the G2 cable entry. Further embodiments

[0045] The present embodiment is not limited to the embodiment described by the above statements and drawings, and for example, the following embodiments also fall within the technical scope of the present invention. 1. In the above-described embodiment, the metal braided portion 3 and the corrugated hose 5 are formed separately, but the metal braided portion 3 may be inserted into the corrugated hose 5 and formed integrally therewith. 2. In the above-described embodiment, the shielding tube 1 is formed only from a metal material, but the shielding tube 1 may also be formed by inserting a metal tube into a resin tube. 3. In the above-described embodiment, the shielding tube 1 and the metal braid portion 3 are provided along the guide region of the wire harness WH to ensure the shielding function. However, if the present invention is used under conditions where shielding is not required, the tube need not be made of a conductive material, and the metal braid portion 3 may also be omitted. LIST OF REFERENCE SYMBOLS 1 umbrella tube 3 metal mesh section 5 corrugated hose 5A combs 5B Troughs 8 pipe-side end section 9 corrugated hose end section 12 fastening tape 14-1 ... 14-4 pipe-side sealing lips 15 pipe-side bevelled surface 17 bevelled surface on the corrugated hose side 20-1 ... 20-4 corrugated hose side sealing lips 21 counteracting recording section G1, G2 cable entry WH wiring harness W latitude region

Claims

[1] Cable bushing (G1, G2) which is designed to cover a pipe (1) into the interior of which a cable is inserted, and a corrugated hose (5), wherein the cable bushing (G1, G2) bridges the pipe (1) and the corrugated hose (5), the corrugated hose (5) forms a flexible bellows shape in which ridges (5A) and troughs (5B) alternate, the cable led out of an end section of the pipe (1) is received in the corrugated hose (5), and the cable bushing (G1, G2) comprises: a tube-side end section (8) which is tubular and can be sealingly connected to an outer peripheral side of the tube (1), a corrugated hose-side end section (9) which is tubular and can be sealingly connected to an outer peripheral side of the corrugated hose (5), and a plurality of sealing lips (14-1 ... 14-4; 20-1 ... 20-4) arranged on respective inner surfaces of the corrugated hose-side end portion (9) and the tube-side end portion (8) such that they are in close contact with an outer surface of the tube (1) or the troughs (5B) of the corrugated hose (5), characterized by , that: a first sealing lip (14-1), a second sealing lip (14-2) and a third sealing lip (14-3) are provided in the pipe-side end section (8), the first sealing lip (14-1) and the third sealing lip (14-3) are arranged outside a width region to which the cable bushing (G1, G2) can be fastened with a fastening band (12) arranged on an outer surface of the pipe-side end section (8), and the second sealing lip (14-2) is provided between the first sealing lip (14-3) and the third sealing lip (14-3) within this width region. [2] Cable bushing (G1, G2) according to claim 1, wherein a beveled surface (15) is formed in a front end portion of the outer surface of at least the pipe-side end portion (8). [3] Cable bushing (G1, G2) according to claim 1 or 2, wherein a portion on the inner surface of the corrugated tube-side end portion (9) located within a width region secured with a fastening band (12) is provided with: the sealing lips (20-1 ... 20-4), and a counteracting receiving portion (21) against which a projecting end face of the combs (5A) of the corrugated hose (5) can rest in order to prevent the sealing lips from collapsing.

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