This invention relates to an electric vehicle charging connector assembly used for charging a power battery of an electric vehicle.

Social problems on environmental and energy affairs have recently demanded provision of an electric vehicle loaded with a power battery. Some types of electric vehicles have been put to practical use. The power battery provided in a body of the electric vehicle needs to be frequently charged and accordingly, an external battery charger needs to be readily connected to the power battery of the electric vehicle. Use of a connector assembly has been proposed for the purpose of connecting between the battery charger and the power battery of the electric vehicle.

The connector assembly used for the above-described purpose includes a vehicle side connector body mounted on the body of the electric vehicle and vehicle side terminals enclosed in the vehicle side connector body. The terminals compose a charging power circuit. The connector assembly further includes an external connector body and external terminals enclosed in the external connector body. The external connector body is mated with and unmated from the vehicle side connector body mounted on the body of the electric vehicle so that the external terminals are connected to and disconnected from the vehicle side terminals respectively.

Electrical connection between the terminals is unstable in the connector assembly of the above-described type in the condition that both connector bodies are not completely intermated such that the terminals are completely interfitted. Charging in such a condition may result in an electrical disadvantage such as generation of arc between the terminals of both sides. However, the conventional connector assemblies are not provided with means with which an operator sees, during a mating work, whether both connector bodies are completely interconnected or not. In this case, the mating work may be completed even though both connector bodies are not completely interconnected because of failure or misjudgment by the operator and consequently, charging may be initiated by mistake.

Other examples of common connector assemblies, however no connector assemblies specifically designed for electric vehicle charging applications are disclosed in US-A-3,613,047 or US-A-4,808,127.

Therefore, an object of the present invention is to provide an electric vehicle charging connector assembly wherein the operator can see, during the mating work, whether the connector bodies are completely mated together or not.

A solution of this object is achieved by what is claimed in claim 1.

Accordingly, the present invention provides an electric vehicle charging connector assembly for externally charging a power battery provided in a body of an electric vehicle, thereby powering the electric vehicle, the connector assembly comprising: a vehicle side connector body suitable to be provided on the body of the electric vehicle; vehicle side power terminals enclosed in the vehicle side connector body, the vehicle side power terminals composing a charging power circuit for the power battery; an external connector body matable with and unmatable from the vehicle side connector body; and external power terminals enclosed in the external connector body to be electrically connected to the respective vehicle side power terminals when the external connector body is mated with the vehicle side connector body. Furthermore according to present invention there is provided a cam connecting mechanism provided either on the vehicle side connector body or on the external connector body so as to be located therebetween when both connector bodies are mated together, the cam connecting mechanism including: cam grooves and cam projections engaged with the respective cam grooves, clearance grooves provided to be continuous to the respective cam grooves of the cam connecting mechanism, each clearance groove extending at the side of the external connector body relative to a final mating location of both connector bodies along a direction in which both connector bodies are mated together, a lock mechanism holding both connector bodies in a mated state when both connector bodies reach the final mating location, and a return spring provided either on the vehicle side connector body or the external connector body so as to be located therebetween when both connector bodies are mated together, the return spring urging both connector bodies in a direction opposite the direction in which both connector bodies are mated together when the cam projections are engaged with the respective clearance grooves.

In mating both connector bodies together, the cam projections are engaged with the respective cam grooves so that the external connector body comes close to the vehicle side connector body such that both connector bodies are in a state immediately before the final mating engagement. When each cam projection reaches a beginning of the clearance groove, the vehicle side connector body is returned with the cam projections along the respective clearance grooves and then is thrust against the return spring so that it comes further close to the external connector body. Both connector bodies are in the state of the final mating engagement when each cam projection reaches the termination of the clearance groove. Subsequently, the lock mechanism is actuated to hold the connector bodies in the state of the final mating engagement. The mating work is thus completed, and the connector bodies are completely mated together such that the terminals are completely connected together without any electrical failure.

In above-described mating work, the operator needs to take it into consideration whether the return spring returns the vehicle side connector body back or not after it is thrust such that each cam projection reaches the termination of the clearance groove. If the vehicle side connector body is caused to return back, the connector bodies are not completely in the state of final mating engagement since the lock mechanism is not actuated. In this case, the vehicle side connector body is again caused to mate with the external connector body and thereafter, the lock mechanism is actuated to hold both connector bodies in the state of final mating engagement. Consequently, the mating work can be prevented from being finished before the connector bodies are not completely interconnected because of failure or misjudgement by the operator.

Advantageous modifications of the invention are subject matter of the subclaims.

The invention now will be described, merely by way of example, with reference to the accompanying drawings, in which:

• Fig. 1 is a sectional view of one embodiment of an electric vehicle charging connector assembly in accordance with the present invention, in which view both connector bodies are unmated:
• Fig. 2 is a sectional view of the connector assembly in the state that a cam projection of the vehicle side connector body has started engaging a cam groove of the external connector body;
• Fig. 3 is a sectional view of the connector assembly in the state that the cam projection has reached a start of a clearance groove :
• Fig. 4 is a sectional view of the connector assembly in the state that the cam projection has reached a termination of the clearance groove such that the connectors are in the final mating engagement;
• Fig. 5 is a perspective view of the external connector of the connector assembly;
• Fig. 6 is an exploded perspective view of the external connector;
• Fig. 7 is a perspective view of the vehicle side connector of the connector assembly;
• Fig. 8 is a front view of the vehicle side connector; and
• Fig. 9 is a schematic side view of an electric vehicle.

One embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 9 schematically illustrates an electric vehicle. A power battery 101 is mounted in a body 100 of the electric vehicle. A vehicle side connector 110 is mounted on one side of the body 100. An external connector 120 connected to a charging power source (not shown) is to be mated with and unmated from the vehicle side connector 110.

Referring to Fig. 1, the vehicle side connector 110 comprises a cylindrical vehicle side connector body 5 formed of a metal and an insulator 2 disposed in the vehicle side connector body 5 and formed of a synthetic resin. Two vehicle side power terminals 3 and three vehicle side signal terminals 4 are mounted in the insulator 2. Each vehicle side power terminal 3 projects in the connector body 5 to serve as a male terminal. Each vehicle side signal terminal 4 is depressed in the insulator 2 to serve as a female terminal. The vehicle side connector body 5 has two cam projections 6 formed on an outer periphery thereof at a front end at intervals of 180 degrees.

The external connector 120 comprises an external connector body 11 formed of an electrically insulative synthetic resin, external power terminals 13 each embedded in a front wall of the connector body 11 and external signal terminals 14 projecting from the front wall of the connector body 11. The external power terminals 13 are formed into female terminals so as to be electrically connected to the vehicle side power terminals 3 when the terminals 3 are fitted into them, respectively. The external signal terminals 14 are formed into male terminals so as to be fitted into the vehicle side signal terminals 4 respectively. Each vehicle side power terminal 3 has a projecting portion projecting from the insulator 2 and each external signal terminal 14 also has a projecting portion projecting from the front wall of the external connector body 5. The projecting portion of each vehicle side power terminal 5 has a length longer than the projecting portion of each external signal terminal 14. Consequently, the signal terminals 4 and 14 are connected and disconnected with a delay relative to connection and disconnection of the power terminals 3 and 13. respectively.

A cylindrical sleeve 16 formed of a metal is mounted on an outer periphery of the external connector body 11 so as to be rotated relative thereto. The sleeve 16 projects forward of the external connector body 11 so as to surround the external signal terminals 14. The external connector body 11 has an engagement groove 15 formed in an overall outer periphery at the rear end thereof. The sleeve 16 has an annular limiting projection 16 formed on its inner periphery at the rear end thereof so that it is projected inward. The limiting projection 16 is fitted into the engagement groove 15 of the external connector body 11 so that axial movement of the sleeve 16 is limited and its rotation is permitted.

The sleeve 16 has two spiral cam grooves 17 formed in the inner periphery thereof. The cam projections 6 of the vehicle side connector body 5 are slidably engaged with the respective cam grooves 17 from the front end of the sleeve 16. Each cam groove 17 has in its rear end a clearance groove 18 extending straight in a direction in which both connectors 110 and 120 are interconnected or in a direction of the axis of rotation of the sleeve 16. Beginning portions of the clearance grooves 18 are continuous to the spiral portions of the cam grooves 17 respectively. Lock grooves 19 are formed to be continuous to terminations of the clearance grooves 18 respectively. The lock grooves 19 compose a lock mechanism for holding both connector bodies 5 and 11 when they reach a final mating position.

The power terminals 3 and 13 are partially connected and the signal terminals 4 and 14 are not connected when each cam projection 6 engages the beginning portion of the clearance groove 18. The connectors 110 and 120 are thus in the state of incomplete connection. When each cam projection 6 engages the termination of the clearance groove 18, the insulators 2 and 11 of the respective connectors 110 and 120 collides with each other such that the power terminals 3 and 13 and the signal terminals 4 and 14 are completely connected, whereupon the connectors 110 and 120 are in the state of final connection. Furthermore, when each cam Projection 6 engages the lock groove 19, the connectors 110 and 120 are held in the final connection state, in which state the connectors 110 and 120 are not unmated even when an external connecting or disconnecting force is applied to them.

A protecting plate 20 is provided in the external connector body 5 of the external connector 120. The protecting plate 20 has guide apertures 21 corresponding to the power terminals 3 and 13 and the signal terminals 4 and 14. The protecting plate 20 includes legs 22 inserted into positioning holes 23 formed in the external connector body 11, respectively, such that the protecting plate comes close to and moves away from the front of the external connector body 11. A return spring 25 comprising a compression coil spring is provided between the protecting plate 20 and the external connector body 11 for urging the protecting plate 20 in a direction in which the plate moves away from the connector body 11. In the state that the connectors 110 and 120 are disconnected, the return spring 25 urges the protecting plate 20 such that the external power terminals 13 and the external signal terminals 14 are covered by the protecting plate 20. Consequently, these terminals are prevented from being touched with hands or suffering from collision of a foreign object, whereby the operator or the like can be prevented from receiving an electric shock or occurrence of a short circuit can be prevented.

An operation for mating the connectors together will now be described. In mating the connectors 110 and 120 together, both connectors are positioned so that the terminals correspond to one another. The cam projections 6 of the vehicle side connector 110 are engaged with the respective cam grooves 17, and the sleeve 16 is rotated relative to the insulators 2 and 11 so that the external connector body 11 comes close to the external connector 120, as shown in Fig. 2. In the meantime, the cam projections 6 slide along the respective cam grooves 17 and the return spring 25 is pushed via the protecting plate 20 by the external connector body 11 to be thereby compressed. The vehicle side power terminals 3 are connected to the external power terminals 13 through the guide apertures 21 of the protecting plate 20, respectively.

The sleeve 16 cannot be rotated when each cam projection 6 engaging the cam groove 17 collides with the beginning portion of the clearance groove 18. The connectors 110 and 120 are in the state of incomplete connection, as shown in Fig. 3. Subsequently, the external connector body 11 is thrust straightforward toward the external connector 120 against the return spring 25 so that both connectors 110 and 120 further come close to each other. In the meantime. the cam projections 6 slide along the respective clearance grooves 18 such that the return spring 25 is further compressed. Consequently, the external signal terminals 14 are connected through the guide apertures 21 of the protecting plate 20 to the vehicle side signal terminals 4, respectively.

The external connector body 11 cannot be thrust when each cam projection 6 collides with the termination of the clearance groove 18. The connectors 110 and 120 are in the state of final connection, as shown in Fig. 4. Subsequently, the sleeve 16 is rotated in the reverse direction so that the cam projections 6 slide along the respective lock grooves 19. The mating work is completed when the cam projections 6 collide with the terminations of the lock grooves 19 respectively such that the sleeve 16 cannot be further rotated. In this state, the cam projections 6 are held in engagement with the respective lock grooves 19 by a frictional force due to urge of the return spring 25 even when the operator releases his or her hold of the sleeve 16. Thus. mating of the connectors 110 and 120 is completed, and the terminals 3, 13, 4 and 14 are held in the state of complete connection without occurrence of any electrical failure. Charging is initiated upon mating of the connectors 110 and 120 as described above. Upon completion of charging, the external connector body 11 is detached from the external connector 120 in a reverse order.

The operator should not finish the above-described mating work when the sleeve 16 has been rotated. Subsequently, the operator needs to thrust the external connector body 11 toward the external connector 120, perceiving the urging force of the return spring 25. Incomplete connection of the terminals due to incomplete mating of the connectors 110 and 120 can be evaded when completion of the thrust of the external connector body 11 is confirmed. More specifically, the urging force of the return spring 25 causes the external connector body 11 to depart from the vehicle side connector 110 when the operator does not perform the operation to lock the connectors 110 and 120 in the state of final connection because of failure in operation or misjudgment by the operator after the external connector body 11 has been thrust toward the external connector 120. Upon confirmation of departure of the external connector body 11 from the vehicle side connector 110, the operator can understand that the connectors 110 and 120 are not locked in the state of final connection and accordingly, are in the state of incomplete connection. In this case. the external connector body 11 is thrust toward the external connector 120 and locked. Subsequently, the operator confirms that the external connector body 11 has not returned, completing the mating work.

According to the above-described connector assembly, the operator can see whether the connectors have been completely mated together or not, in the midst of the mating work. If the mating work is completed with the connectors in the state of incomplete connection, the connectors are maintained in the incomplete connection state when charging is initiated. However, such a situation can be avoided even when the operator is inexperienced in mating the connectors such as in the case where charging is performed at ordinary household.

In the above-described embodiment, the projecting portion of each external signal terminal 14 has the length shorter than the projecting portion of each vehicle side power terminal 3. Consequently, the signal terminals 4 and 14 are not connected in the incomplete connection state wherein the power terminals 3 and 13 are partially interfitted, whereby the incomplete connection of the connectors is electrically detected. Consequently, a safety countermeasure can be readily taken when the connectors 110 and 120 are incompletely mated together, for example, the power terminals 3 and 13 are not energized.

In the foregoing embodiment the cam grooves 17 are formed in the inner periphery of the sleeve 16 of the external connector 120 and the cam projections 6 are formed on the outer periphery of the vehicle side connector body 5 of the vehicle side connector 110. The cam grooves may be formed in the outer periphery of the sleeve 16 and the cam projections may be formed on the inner periphery of the vehicle side connector body of the vehicle side connector, instead. Furthermore. the cam grooves may be formed in the vehicle side connector body and the cam projections may be formed on the external connector body.

Although the return spring 25 is provided in the external connector 120 in the foregoing embodiment, it may be provided in the vehicle side connector body.

In the foregoing embodiment the cam projections 6 are engaged with the respective cam grooves 17 and then the sleeve 16 is rotated for the purpose of connection of the connectors 110 and 120. The cam grooves may be formed in levers rotatably mounted on either connector and the cam projections may be formed on the other connector, instead. In this modified form, the action of the levers is utilized to mate the connectors together.