EP3193409A1

EP3193409A1 - Rotary connector

Info

Publication number: EP3193409A1
Application number: EP17150092.9A
Authority: EP
Inventors: Yuki HIRAO
Original assignee: Alps Electric Co Ltd
Current assignee: Alps Alpine Co Ltd
Priority date: 2016-01-13
Filing date: 2017-01-03
Publication date: 2017-07-19
Anticipated expiration: 2037-01-03
Also published as: EP3193409B1; JP2017126464A; JP6605337B2

Abstract

The present invention provides a rotary connector in which water is prevented from entering the inside of the rotary connector. A rotary connector (1) includes an annular fixed-side housing (2) and an annular movable-side housing (3) which is rotatably assembled to the fixed-side housing (2) and in which a steering shaft (50) is inserted into a center portion of the annular movable-side housing (3). An annular space portion (4) is formed in the inside of the rotary connector (1) which is surrounded by the fixed-side housing (2) and the movable-side housing (3) . A cable (5) for securing electric conduction between the fixed-side housing (2) and the movable-side housing (3) is accommodated in the annular space portion (4) . A tapered guide portion (14) and a tapered groove portion (15) serving as waterproofing means for preventing condensed water from entering the inside of the rotary connector (1) are formed on the surface of an upper rotor portion 3A of the movable-side housing 3.

Description

CLAIM OF PRIORITY

This application claims benefit of Japanese Patent Application No. 2016-004635 filed on January 13, 2016 , which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rotary connector for transmitting an electric signal between a fixed-side housing and a movable-side housing, and particularly, to a rotary connector having waterproofing measures for preventing water from entering the inside of the rotary connector.

2. Description of the Related Art

In the related art, in an automobile, a rotary connector in known, which electrically connects an electric device provided on a steering wheel side and an electric device provided on a vehicle body side.
The rotary connector includes a fixed-side housing which is attached to the vehicle body side, a movable-side housing which is assembled to a steering shaft to be rotatable with respect to the fixed-side housing, and a cable which is accommodated in an annular space portion formed between the housings and electrically connects connector portions provided in the housings to each other.
The rotary connector having the above-described configuration is used as electrical connection means of an airbag system mounted on a steering wheel of an automobile, a horn circuit, various operation switches, or the like.
Japanese Unexamined Patent Application Publication No. 2007-220505 discloses a technology in which dust-proofing measures are provided in a rotary connector. In the rotary connector, a dust-proofing ring plate is disposed to come into close-contact with an outer circumferential surface of a rotary tube attached to a rotary cover and an inner circumferential edge of a hole portion of a bottom cover attached to the fixed cover, and dust, abrasion powder, grease, or the like is prevented from entering the inside of the rotary connector from a portion between the rotary tube and the bottom cover.
Meanwhile, the rotary connector is used so that a metal steering shaft disposed in a vehicle cabin is inserted into a movable-side housing of the rotary connector and a fixed-side housing thereof is mounted on the vehicle body side.
When an engine is started to travel an automobile in a cold district, a vehicle cabin is warmed by heating, and the cabin is transferred from a low-temperature environment to a high-temperature environment.
When the cabin is transferred from the low-temperature environment to the high-temperature environment, condensation is generated in the steering shaft. If condensation is generated in the steering shaft, for example, condensed water falls on the surface of the movable-side housing from a fitted portion between the steering shaft and the movable-side housing, and the condensed water is easily collected in the surface of the movable-side housing.
If the condensed water is collected in the upper surface of the movable-side housing, the condensed water enters the inside of the rotary connector from a hole formed on the upper surface of the movable-side housing or the like and reaches the connection portion between the cable and the connector portion incorporated into the inside of the rotary connector, and there is a concern that an electric circuit is short-circuited.
In the technology disclosed in Japanese Unexamined Patent Application Publication No. 2007-220505 , it is possible to prevent dust, abrasion power, grease, or the like from entering the inside of the rotary connector. However, it is not possible to prevent condensed water from entering the inside of the rotary connector.

SUMMARY OF THE INVENTION

The present invention provides a rotary connector in which even in a case where water falls on a surface of a movable-side housing, the water can be discharged to the outside of the movable-side housing before the fallen water is collected in the surface of the movable-side housing, and it is possible to prevent water from entering the inside of the rotary connector.
According to an aspect of the present invention, there is provided a rotary connector, including: an annular fixed-side housing; an annular movable-side housing which is rotatably assembled relative to the fixed-side housing and in which a steering shaft is inserted into a center portion of the annular movable-side housing; and a cable which is incorporated into an annular space formed between the fixed-side housing and the movable-side housing and is configured to electrically connect a fixed-side connector portion provided in the fixed-side housing and a movable-side connector portion provided in the movable-side housing to each other, in which waterproofing means for preventing water fallen on the surface of the movable-side housing from entering the inside of the annular space portion and the water from being attached to the movable-side connector portion is provided on a surface portion side of the movable-side housing.
According to this configuration, it is possible to discharge the water fallen on the surface of the movable-side housing to the outside of the movable-side housing before the water is collected in the upper surface of the movable-side housing, and it is possible to prevent short circuit of an electric circuit inside the rotary connector.
Preferably, the water proofing means is provided on a surface portion side positioned in a lower region of the movable-side housing when the fixed-side housing is mounted on a vehicle body side and the movable-side housing is positioned at a neutral position with respect to the fixed-side housing.
According to this configuration, it is possible to collect the water fallen on the surface of the movable-side housing in the lower region of the movable-side housing and discharge the water to the outside of the movable-side housing.
Preferably, an outer connector fitting portion configuring the movable-side connector portion protrudes from the surface portion side positioned in the lower region of the movable-side housing, and the waterproofing means is provided on the surface of the outer connector fitting portion.
According to this configuration, it is possible to discharge the water fallen on the surface of the movable-side housing to the outside using the surface of the outer connector fitting portion, and it is possible to reliably discharge water.
Preferably, the waterproofing means includes a guide portion which is configured to introduce the water fallen on the surface of the movable-side housing to the outside of the movable-side housing.
According to this configuration, it is possible to smoothly discharge the water fallen on the surface of the movable-side housing to the outside.
Preferably, the waterproofing means includes a groove portion which is configured to prevent a flow of the water fallen on the surface of the movable-side housing toward the movable-side connector portion.
Accordingly, it is possible to contain the water fallen on the surface of the movable-side housing in the groove portion.
According to the present invention, it is possible to provide a rotary connector in which even in a case where water falls on the surface of the movable-side housing, the water can be discharged to the outside of the movable-side housing before the fallen water is collected in the surface of the movable-side housing, and the water is prevented from entering the inside of the rotary connector.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a front view of a rotary connector according to an embodiment of the present invention.
Fig. 2 is a side view of the rotary connector.
Fig. 3 is a partially exploded perspective view showing an outline of the rotary connector.
Fig. 4 is an enlarged perspective view showing a portion of waterproofing means of the rotary connector.
Fig. 5 is an enlarged perspective view showing a main portion of the waterproofing means of the rotary connector.
Fig. 6 is an enlarged perspective view showing another main portion of the waterproofing means of the rotary connector.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a rotary connector according to an embodiment of the present invention is described with reference to the drawings.
Fig. 1 is a front view of the rotary connector according to the embodiment of the present invention. Fig. 2 is a side view of the rotary connector according to the present embodiment and shows a state where the rotary connector is mounted on a steering shaft. Fig. 3 is a partially exploded perspective view showing an outline of the rotary connector according to the present embodiment.
A rotary connector 1 is a connection device for transmitting an electric signal between a steering shaft 50 side serving as a steering device of an automobile and a vehicle body side.
As shown in Figs. 1 to 3, the rotary connector 1 includes an annular fixed-side housing 2 which is attached to a steering column 51 fixed to the vehicle body side, and an annular movable-side housing 3 which is rotatably assembled to the fixed-side housing 2 and into which a steering shaft 50 enclosed in a steering column 51 is inserted.
The fixed-side housing 2 includes a outer tube portion 2A which is formed of a synthetic resin, an annular bottom plate portion 2B which is attached to the outer circumferential edge of the outer tube portion 2A and is formed of a synthetic resin, and a leg portion 2C which is integrally formed with the annular bottom plate portion 2B. The leg portion 2C is attached to the steering column 51 on the vehicle body side and the fixed-side housing 2 is fixed to the steering column 51.
The movable-side housing 3 includes a disk-shaped upper rotor portion 3A which is formed of a synthetic resin, a disk-shaped lower rotor portion 3B which faces the upper rotor portion 3A with a predetermined distance and is formed of a synthetic resin, and a tubular intermediate rotor portion 3C which is provided on the intermediate portion between the upper rotor portion 3A and the lower rotor portion 3B and connects the rotor portions 3A and 3B. The steering shaft 50 is inserted into the intermediate rotor portion 3C, and the movable-side housing 3 is assembled and fixed to the steering shaft 50 side. The movable-side housing 3 is rotated in both forward and backward directions (arrow A direction and arrow B direction in Fig. 1) relative to the fixed-side housing 2 with an axis line as a center.
The fixed-side housing 2 and the movable-side housing 3 are assembled to each other, and an annular space portion 4 is formed in the inside of the rotary connector 1 which is surrounded by the housings 2 and 3. A cable 5 for securing electric conduction between the fixed-side housing 2 and the movable-side housing 3 is accommodated in the annular space portion 4. For example, as the cable 5, a flat cable 5 having flexibility is used. The flat cable 5 is accommodated in the annular space portion 4 so as to be spirally wounded, and performs operations according to a winding rotation or an unwinding rotation from a neutral position (a position which causes an automobile to straightly travel) of the movable-side housing 3 with respect to the fixed-side housing 2 according to the rotation of the movable-side housing 3.
A fixed-side connector portion 6 is provided on the outer tube portion 2A configuring the fixed-side housing 2 so as to protrude from the outer circumference of the outer tube portion 2A toward the outside.
A movable-side lead block 7A configuring a movable-side connector portion 7 is attached to the rear surface side of the upper rotor portion 3A configuring the movable-side housing 3.
One end of the flat cable 5 is electrically connected to a fixed-side lead block (not shown) configuring the fixed-side connector portion 6, and the other end of the flat cable 5 is electrically connected to the movable-side lead block 7A of the movable-side connector portion 7.
When the fixed-side housing 2 is mounted on the vehicle body side, the steering shaft 50 is inserted into the intermediate rotor portion 3C of the movable-side housing 3, and a steering handle is maintained at the neutral position (position which causes an automobile to straightly travel), that is, the movable-side housing 3 is positioned at the neutral position with respect to the fixed-side housing 2, an outer connector fitting portion 8 configuring the movable-side connector portion 7 protrudes from the surface portion side positioned in a lower region of the upper rotor portion 3A of the movable-side housing 3.
A connector portion (not shown) for connecting a cable connected to an airbag system, a horn switch circuit, or the like is fitted to the outer connector fitting portion 8. The outer connector fitting portion 8 is divided into a first fitting portion 10 and the second fitting portion 11.
A positioning pin 9 for positionally fixing the movable-side housing 3 at a predetermined position on the steering shaft 50 side protrudes from the surface on the upper side of the upper rotor portion 3A of the movable-side housing 3.
As shown in Fig. 2, the rotary connector 1 having the above-described configuration is attached to the steering column 51 so as to be inclined at a predetermined angle (θ) toward the front (left direction in Fig. 2) of a driver.
An opening portion 3a from which the movable-side lead block 7A is exposed is formed in the vicinity of the second fitting portion 11 in the upper rotor portion 3A of the movable-side housing 3. The opening portion 3a is freely opened and closed by a cover 12. A cover portion 13 which is integrally formed with the cover 12 is provided in the second fitting portion 11.
An opening portion 13A which is fitted to a locking portion 11A protruding from the main body of the second fitting portion 11 is formed in the cover portion 13, and the locking portion 11A and the opening portion 13A are fitted to each other. Accordingly, the cover 12 and the cover portion 13 are fastened so as to cover the opening portion 3a of the upper rotor portion 3A. In addition, the fitting between the locking portion 11A and the opening portion 13A is released, and the opening portion 3a of the upper rotor portion 3A can be opened.
Waterproofing means is provided on the surface portion side of the movable-side housing 3, and the waterproofing means prevents condensed water fallen on the surface of the upper rotor portion 3A of the movable-side housing 3 from entering the inside of the annular space portion 4, prevents the water from being attached to the movable-side lead block 7A of the movable-side connector portion 7, and prevents short circuit of an electric circuit.
In the upper rotor portion 3A of the movable-side housing 3 , a tapered guide portion 14 configuring the waterproofing means is provided in a region in which an upper corner portion 10a of the first fitting portion 10 of the outer connector fitting portion 8 is positioned. The guide portion 14 has a function which introduces condensed water fallen on an upper surface 10A of the first fitting portion 10 to the outside of the movable-side housing 3.
In addition, in the first fitting portion 10, a groove portion 15 configuring the waterproofing means is formed on the upper surface opposite to the guide portion 14 in a direction perpendicular to the rotation direction of the movable-side housing 3. The groove portion 15 has a function which prevents the condensed water fallen on the upper surface 10A of the first fitting portion 10 from being transferred to the upper surface 10A of the first fitting portion 10, and prevents the condensed water from flowing to the side in which the movable-side lead block 7A of the movable-side connector portion 7 is provided.
In addition, the groove portion 15 is formed from the upper surface 10A of the first fitting portion 10 to the surface of the upper rotor portion 3A of the movable-side housing 3.
Next, operations of the guide portion 14 and the groove portion 15 configuring the waterproofing means will be described with reference to Figs. 4 to 6.
Fig. 4 is an enlarged perspective view showing the portion of the waterproofing means of the rotary connector, and is a view showing the portion of the outer connector fitting portion. Fig. 5 is an enlarged perspective view showing a main portion of the waterproofing means of the rotary connector, and is a view showing the portion of the guide portion configuring the waterproofing means. Fig. 6 is an enlarged perspective view showing another main portion of the waterproofing means of the rotary connector, and is a view showing the portion of the groove portion configuring the waterproofing means.
The metal steering shaft 50 disposed in a cabin of an automobile is inserted into the intermediate rotor portion 3C, and the rotary connector 1 is assembled to the steering shaft 50 side.
When an engine is started to travel an automobile during a winter season in which a temperature decreases, the cabin of the automobile is warmed, and the cabin is transferred from a low-temperature environment to a high-temperature environment.
When the cabin is transferred from a low-temperature environment to a high-temperature environment, condensation is generated in the steering shaft 50.
If the condensation is generated in the steering shaft 50, for example, as shown by an arrow C in Fig. 4, the condensed water flows out from a contact portion between the steering shaft 50 and the intermediate rotor portion 3C of the movable-side housing 3, is transferred to the upper surface of the upper rotor portion 3A of the movable-side housing 3, and falls on the upper surface 10A of the first fitting portion 10.
In a case where the condensed water falls on the upper surface 10A of the first fitting portion 10, the condensed water is not collected in the upper surface 10A of the first fitting portion 10, is transferred to the upper surface 10A of the first fitting portion 10 as shown by an arrow D in Fig. 4, moves toward the guide portion 14, and is discharged from the guide portion 14 to the outside of the movable-side housing 3 as shown by an arrow E in Fig. 4. That is, the condensed water is introduced to the downstream side by the guide portion 14 which is inclined in a taper shape and surface tension of the condensed water is destroyed. Accordingly, the condensed water is not collected and is rapidly discharged to the outside of the movable-side housing 3.
In this way, since the condensed water is discharged to the outside of the movable-side housing 3, even when condensation is generated in the steering shaft 50 and condensed water falls on the surface of the upper rotor portion 3A of the movable-side housing 3, the condensed water does not enter the inside of the rotary connector 1 from a hole which is formed in the upper rotor portion 3A or the like and does not reach the movable-side lead block 7A of the movable-side connector portion 7 incorporated into the inside of the rotary connector 3 , and it is possible to prevent short circuit of an electric circuit.
As shown in Fig. 2, since the movable-side housing 3 is mounted on the steering shaft 50 so as to be inclined toward the front side at the predetermined angle (θ), the condensed water fallen on the upper surface 10A of the first fitting portion 10 is not collected in the upper surface of the upper rotor portion 3A of the movable-side housing 3, flows to an edge portion 17 formed on the base of the first fitting portion 10, and is introduced toward the guide portion 14 along the edge portion 17. Accordingly, the condensed water does not move to an inlet 10b of the first fitting portion 10, and it is possible to smoothly move the condensed water to the guide portion 14.
In addition, since the condensed water does not move to the inlet 10b side of the first fitting portion 10, the condensed water does not enter the inside of the first fitting portion 10, and it is possible to prevent short circuit of the electric circuit between the connection portions for connecting the cable fitted to the first fitting portion 10.
In addition, by rotating the movable-side housing 3 in the arrow A direction in Fig. 1, the movement in the guide portion 14 direction of the condensed water fallen on the upper surface 10A of the first fitting portion 10 of the outer connector fitting portion 8 is promoted. Accordingly, after a warm-up operation is performed when an automobile starts, by lightly rotating a handle, it is possible to discharge the condensed water fallen on the upper surface 10A of the first fitting portion 10 to the guide portion 14 side.
In addition, the condensed water fallen on the upper surface 10A of the first fitting portion 10 of the outer connector fitting portion 8 is collected in the portion of the groove portion 15 formed on the upper surface 10A of the first fitting portion 10 due to surface tension. Accordingly, it is possible to prevent the condensed water from moving toward the second fitting portion 11 side of the outer connector fitting portion 8 over the groove portion 15.
In this way, since the condensed water is collected in the portion of the groove portion 15, even when condensation is generated in the steering shaft 50 and the condensed water falls on the upper surface 10A of the first fitting portion 10, the condensed water does not enter the inside of the rotary connector 1 from a gap 18 between the first fitting portion 10 and the cover portion 13 of the second fitting portion 11, or a gap 19 between the upper rotor portion 3A of the movable-side housing 3 and the cover 12 of the first fitting portion 10, the condensed water does not reach the movable-side lead block 7A of the movable-side connector portion 7 incorporated into the inside of the rotary connector 3, and it is possible to prevent short circuit of the electric circuit.
In addition, the groove portion 15 which is formed on the upper surface 10A of the first fitting portion 10 of the outer connector fitting portion 8 is formed over the surface of the upper rotor portion 3A, and even when the condensed water moves in the second fitting portion 11 direction along the edge portion 17 of the base of the first fitting portion 10, the condensed water is collected in the portion of the groove portion 15 due to surface tension. Accordingly, it is possible to prevent the condensed water from moving toward the second fitting portion 11 side of the outer connector fitting portion 8 over the groove portion 15.
In this way, according to the rotary connector 1 of the present embodiment, the condensed water fallen on the upper surface 10A of the first fitting portion 10 of the outer connector fitting portion 8 can be discharged to the outside before being collected in the upper surface 10A of the first fitting portion 10, and it is possible to prevent the condensed water from entering the inside of the rotary connector 1. Accordingly, the condensed water does not reach the movable-side lead block 7A of the movable-side connector portion 7 incorporated into the inside of the rotary connector 1, and it is possible to prevent short circuit of the electric circuit.
The present invention is not limited to the above-described embodiment. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims of the equivalents thereof.
In the above-described embodiment, the case is exemplified in which the waterproofing means is provided on the surface of the upper rotor portion 3A in the lower region of the movable-side housing 1 and the upper surface 10A of the first fitting portion 10 of the outer connector fitting portion 8. However, the present invention may have a configuration in which the waterproofing means of the present invention is provided on the surface side of the movable-side housing 3, condensed water fallen on the surface of the movable-side housing 3 is prevented from entering the inside of the rotary connector 1, and short circuit of the electric circuit of the movable-side connector portion 7 is prevented.
In addition, the waterproofing means of the present invention may have one of the guide portion 14 and the groove portion 15 as long as it has the function which prevents the condensed water fallen on the surface of the movable-side housing 1 from entering the inside of the rotary connector 1 and prevents short circuit of the electric circuit of the movable-side connector portion 7.
In addition, the waterproofing means of the present invention may have a configuration in which a wall portion is provided instead of the groove portion 15 and movement of condensed water is contained by the wall portion.
The present invention can be applied to an on-vehicle electric component which prevention of short circuit of an electric circuit due to condensed water is required.

Claims

A rotary connector, comprising:
an annular fixed-side housing (2);

an annular movable-side housing (3) which is rotatably assembled relative to the fixed-side housing (2) and in which a steering shaft (50) is inserted into a center portion of the annular movable-side housing (3); and

a cable (5) which is incorporated into an annular space (4) formed between the fixed-side housing (2) and the movable-side housing (3) and is configured to electrically connect a fixed-side connector portion (6) provided in the fixed-side housing (2) and a movable-side connector portion (7) provided in the movable-side housing (3) to each other,
wherein waterproofing means for preventing water fallen on the surface of the movable-side housing (3) from entering the inside of the annular space portion (4) and the water from being attached to the movable-side connector portion (7) is provided on a surface portion side of the movable-side housing (3).
The rotary connector according to claim 1,
wherein the water proofing means is provided on a surface portion side positioned in a lower region of the movable-side housing (3) when the fixed-side housing (2) is mounted on a vehicle body side and the movable-side housing (3) is positioned at a neutral position with respect to the fixed-side housing (2).
The rotary connector according to claim 2,
wherein an outer connector fitting portion (8) configuring the movable-side connector portion (7) protrudes from the surface portion side positioned in the lower region of the movable-side housing (3), and the waterproofing means is provided on the surface of the outer connector fitting portion (8).
The rotary connector according to any one of claims 1 to 3,
wherein the waterproofing means includes a guide portion (14) which is configured to introduce the water fallen on the surface of the movable-side housing (3) to the outside of the movable-side housing (3).
The rotary connector according to any one of claims 1 to 4,
wherein the waterproofing means includes a groove portion (15) which is configured to prevent a flow of the water fallen on the surface of the movable-side housing (3) toward the movable-side connector portion (7).