Power source device

A power source device includes a battery assembly which includes a plurality of batteries each having a positive electrode at one end and a negative electrode at the other end, a plurality of connecting members, each of which connects the positive electrode of one battery and the negative electrode of the other battery of the battery assembly, the one and the other batteries adjoining each other, and a plate to which the connecting members are attached, and the plate adapted to the battery assembly. The battery assembly and the plate include a positioning section that relatively positions the battery assembly and the plate. The battery assembly and the plate include a plate displacement section that displaces the plate so that the connecting members relatively abut against the corresponding positive electrodes and negative electrodes of the battery assembly when the plate is mounted on the battery assembly.

BACKGROUND

The present invention relates to a power source device including a plurality of batteries connected in series, the power source device mounted for example on a hybrid vehicle capable of traveling by a driving force from an internal-combustion engine or a motor, or an electric vehicle.

A hybrid vehicle traveling by a driving force from an internal-combustion engine or a motor, or an electric vehicle traveling by a driving force from a motor includes a power source device for storing and releasing electric energy. The power source device includes a battery assembly composed of a plurality of batteries. The batteries are connected in series to obtain a desired voltage. For example, a nickel metal hydride (NiMH) battery is used as such a battery.

The power source device connects, by using a connecting member, the positive electrode of one battery of a pair of batteries adjacent to each other out of a plurality of batteries and the negative electrode of the other battery of the pair of batteries to connect a plurality of batteries of a battery assembly in series. This configuration makes it necessary to assemble a plurality of connecting members to a battery assembly thus making cumbersome the assembly work of a power source device. This is more eminent by an increase in the number of batteries constituting a power source device. This configuration may be a hindrance to a compact, lightweight and simple design of a power source device.

In order to solve such problems, various types of power source devices have been used (for example, refer to Patent Reference 1). This type of power source device includes a battery assembly composed of a plurality of batteries, a plurality of bus bars as connecting members for connecting the batteries in series, and a plate on which the plurality of bus bars are attached and which is mounted on the battery assembly. On one surface of the battery body of a battery are arranged a positive electrode and a negative electrode. On the perimeter surface of the positive and negative electrodes is formed a screw groove. The plate has a planar shape formed into an almost flat rectangular plate. The bus bar and the plate respectively include a plurality of holes used to route a positive electrode and a negative electrode.

To assemble such a power source device, a plurality of batteries are arranged side by side so that the positive electrode of a battery will be adjacent to the negative electrode of a separate battery. Next, a plate including a plurality of bus bars in a predetermined position is laid on the batteries. The positive and negative electrodes of the batteries are routed through the plate holes and bus bar holes to connect the plate and the bus bars to the battery assembly. Finally, nuts are screwed into the electrodes where screw grooves are formed to fix the connection of the battery assembly and the plate as well as bus bars. This connects the batteries in series by way of a plurality of bus bars.

With the power source device of the above configuration, a plurality of bus bars are attached to a plate before the plate is mounted on the battery assembly. Thus, connection of the battery assembly and the plate as well as the plurality of bus bars is complete when the positive and negative electrodes of the batteries are simultaneously routed through the plurality of holes in the plate and the holes for the plurality of bus bars attached to the plate and are screwed. This has simplified the assembly work in connecting a plurality of batteries of a battery assembly in series.

With the power source device described in Patent Reference 1, the positive and negative electrodes of the batteries are simultaneously routed through the plurality of holes in the plate and the holes for the plurality of bus bars attached to the plate before the plate is mounted on the battery assembly. The electrodes slide on the inner surfaces of the plate holes and bus bar holes to cause friction, which makes it difficult to assemble a plate to a battery assembly thus placing a load on the worker. When the number of batteries, that is, the number of electrodes in a battery assembly is increased for multi-pole configuration to raise the voltage of the power source device, the load on the worker increases.

SUMMARY

An object of the invention is to provide a power source device capable of simplifying the assembly work.

In order to solve the problems and attain the object, the first aspect of the invention provides a power source device comprising:

a battery assembly which includes a plurality of batteries each having a positive electrode at one end and a negative electrode at the other end;

a plurality of connecting members, each of which connects the positive electrode of one battery and the negative electrode of the other battery of the battery assembly, the one and the other batteries adjoining each other; and

a plate to which the connecting members are attached, and the plate attached to the battery assembly,

wherein the battery assembly and the plate include a positioning section that relatively positions the battery assembly and the plate; and

wherein the battery assembly and the plate include a plate displacement section that displaces the plate so that the connecting members relatively abut against the corresponding positive electrodes and negative electrodes of the battery assembly when the plate is attached to the battery assembly.

The second aspect of the invention provides the power source device according to the first aspect, wherein the positioning section includes a plurality of positioning projections protruding from one surface of the battery assembly and a plurality of positioning holes arranged in the plate into which the positioning projections are respectively inserted; and

wherein a diameter of each of the positioning holes is greater than that of each of the positioning projections.

The third aspect of the invention provides the power source device according to the first or second aspect, wherein the plate displacement section includes a plurality of guide projections protruding from one surface of the battery assembly and a plurality of guide holes arranged in the plate into which the guide projections are respectively inserted; and

wherein the connecting members are inclined in a direction in which the connecting members respectively leave the corresponding positive electrodes and negative electrodes as the guide projections leave the battery assembly.

The fourth aspect of the invention provides the power source device according to any one the first to third aspects, wherein the plate includes:a main body arranged at the center of the battery assembly;a pair of outer side parts arranged parallel to the main body and sandwiching the main body therebetween; andelastically deformable coupling parts respectively coupling the main body to the pair of outer side parts.

The first aspect of the invention includes the positioning section for relatively positioning the battery assembly and the plate and the plate displacement section for displacing the plate so that a plurality of connecting members respectively abut against the corresponding positive electrodes and negative electrodes when the plate is mounted on the battery assembly. It is thus possible to readily arrange a connecting member in a desired position of a battery assembly, thereby reducing the working man-hours of assembling a connecting member to a battery assembly.

With the second aspect of the invention, the positioning section includes the positioning projections protruding from one surface of the battery assembly and the positioning holes arranged in the plate, each of the positioning holes having a diameter formed larger than that of the positioning boss. It is thus possible to position the battery assembly and the plate by inserting the positioning projections into the positioning holes. It is thus possible to readily arrange the plate on the battery assembly, thereby reducing the working man-hours of assembling the connecting member to the battery assembly.

With the third aspect of the invention, the plate displacement section includes the guide projections protruding from one surface of the battery assembly and the guide holes arranged in the plate into which the guide projections are respectively inserted. The plurality of connecting members are inclined in the direction in which the connecting members respectively leave the corresponding positive electrodes and negative electrodes as the guide projections leave the connecting members. It is thus possible to displace the plate with respect to the battery assembly in a direction in which the connecting members respectively approach the corresponding positive electrodes and negative electrodes by inserting the guide projections into the guide holes. This allows the connecting members to respectively abut against the corresponding positive electrodes and negative electrodes.

With the fourth aspect of the invention, the plate includes the main body and the pair of outer side parts. The outer side parts as a pair are respectively coupled to the main body via the elastically deformable coupling parts, thus respectively displacing the main body and the pair of outer side parts relative to the battery assembly. This allows the connecting members to respectively abut against the corresponding positive electrodes and negative electrodes.

As described above, with the first aspect of the invention, it is thus possible to readily arrange the connecting member in a desired position of the battery assembly, thereby reducing the working man-hours of assembling the connecting member to the battery assembly. This simplifies the assembly work of a power source device.

With the second aspect of the invention, it is thus possible to position the battery assembly and the plate by inserting the positioning projections into the positioning holes. It is thus possible to readily arrange the plate on the battery assembly, thereby reducing the working man-hours of assembling the connecting member to the battery assembly. This simplifies the assembly work of a power source device.

With the third aspect of the invention, it is thus possible to displace the plate with respect to the battery assembly in a direction in which the connecting members respectively approach the corresponding positive electrodes and negative electrodes by inserting the guide projections into the guide holes. This allows the connecting members to respectively abut against the corresponding positive electrodes and negative electrodes. It is thus possible to readily arrange the connecting member in a desired position of the battery assembly, thereby reducing the working man-hours of assembling a connecting member to a battery assembly.

With the fourth aspect of the invention, it is possible to respectively displace the main body and the pair of outer side parts relative to the battery assembly. This allows the plurality of connecting members to respectively abut against the corresponding positive electrodes and negative electrodes. It is thus possible to reliably arrange the connecting member in a desired position of a battery assembly.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

A power source device according to an embodiment of the invention will be described referring toFIGS. 1 through 7. A power source device1according to an embodiment of the invention is mounted on a hybrid vehicle traveling by a driving force from an internal-combustion engine or a motor, or an electric vehicle traveling by a driving force from a motor.

As shown inFIG. 1, the power source device1according to the invention includes a battery assembly2, bus bars8,9as connecting members for connecting batteries3described later in series, and a plate10on which the bus bars8,9are attached and which is mounted on the battery assembly2.

The battery assembly2includes a plurality of batteries3as shown inFIG. 1. The battery3includes a battery body4in a square shape, a positive electrode (hereinafter referred to as the positive pole)6, and a negative electrode (hereinafter referred to as the negative pole)7. The positive pole6is arranged on one end of the battery body4. The negative pole7is arranged on the other end of the battery body4. The positive pole6and the negative pole7are formed into a prism shape and protrude in the same direction from one end surface5(hereinafter referred to as one end surface) of the battery body4in parallel to each other.

As shown inFIG. 1, the plurality of batteries3are arranged in one direction (arrow H inFIG. 1) with one end surface5of each of the battery bodies4is positioned in a same plane so that the positive pole6and the negative pole7of batteries3adjacent to each other will adjoin each other. The plurality of batteries3are arranged in two rows so that the batteries3will be opposed to each other in a direction crossing one direction H and the one direction H the batteries3in one row adjoin each other will be parallel to the one direction H the batteries3in the other row adjoin each other. The positive pole6and the negative pole7of a battery3and another adjacent to each other adjoin each other. In other words, the batteries3are arranged with the positive pole6and the negative pole7placed in alternately opposed directions.

As shown inFIG. 1, the battery assembly2includes a binding band11for binding and fixing together a plurality of batteries3, an end plate12, an inter-battery plate20, a positioning boss13, and a guide boss14.

A plurality of binding bands11made of an insulating material are formed into a band plate. The plurality of binding bands11are respectively arranged on the top surface2aof the battery assembly2and the bottom surface2bopposed to the top surface2a. The plurality of binding bands11are respectively arranged parallel to the one direction H in which the batteries3are arranged and spaced relation to each other.

The end plate12is made of an insulating material and formed into a square shape. The end plates12as a pair are arranged each at both ends of the battery assembly2in the one direction H. As shown inFIG. 1or2, the end plates12a,12bsandwich the plurality of batteries3and inter-battery plates20therebetween and are each fixed to both ends of the binding band11in its longitudinal direction by way of bolts, thus binding or integrating to hold the plurality of batteries3and inter-battery plates20.

As shown inFIG. 1or4, the positioning boss13is formed into the shape of a circular cylinder and longer than the guide boss14. The positioning boss13protrudes in vertical direction from one end plate12aarranged on the side of one battery3apositioned at one end of the battery assembly2among the plurality of batteries3arranged in the one direction H of the battery assembly2. The positioning projections13as a pair are arranged while spaced relation to each other in a direction crossing the one direction H of the battery assembly2. The positioning projections13as a pair are parallel to each other and arranged to pass through positioning holes27described later. The positioning projections13and positioning holes27described later together form a positioning section, which relatively positions the battery assembly2and the plate10.

The inter-battery plate20is made of an insulating material and formed into a square shape. A plurality of inter-battery plate20are arranged between a plurality of batteries3arranged in the one direction H of the battery assembly2, as shown inFIG. 1or2.

As shown inFIG. 1or4, the guide boss14is formed in the shape of a circular cylinder and a plurality of guide projections14are arranged. Each of the plurality of guide projections14protrudes from one surface20apositioned in the same plane as the one end surface5of the plurality of batteries3of the inter-battery plate20. Each of the plurality of guide projections14is arranged at one of the ends of each inter-battery plate20opposed in a direction crossing the one direction H in alternately opposed directions.

The plurality of guide projections14are formed to be inclined so as to gradually approach the other end of the battery assembly2in the one direction H as guide projections14leave the inter-battery plate20, that is, the battery assembly2. The guide projections14are formed to be inclined in a direction in which a plurality of bus bars8,9respectively leave the corresponding positive poles6and negative poles7when the guide projections14are inserted into guide holes28described later as the guide projections14leave the battery assembly2.

As shown inFIG. 2or3, the plurality of guide projections14are arranged each at both ends opposed in a direction crossing the one direction H of the battery assembly2so as to pass through guide holes28described later arranged equidistantly in the one direction H. The guide projections14and the guide holes28described later together form a plate displacement section, which displaces the plate10with respect to the battery assembly2in a direction in which the plurality of bus bars8,9respectively approach the corresponding positive poles6and negative poles7.

A plurality of bus bars8,9each formed by a conductive metal are provided. As shown inFIGS. 1 to 3, the bus bars8are formed into band plates and arranged on the surface21aof the main body21(described later) of the plate10in a direction parallel to a direction crossing the one direction H in which the plurality of batteries3are arranged, and mounted inside a bus bar accommodating part24described later. The plurality of bus bars8have their positive poles6and negative poles7respectively connected to one surface15opposed in the one direction H to connect the positive pole6of a battery3and the adjacent negative pole7of an adjoining battery3.

As shown inFIGS. 1 to 3, the bus bar9includes a positive pole connecting wall17connected to the positive pole6, a negative pole connecting wall18connected to the negative pole7, and a coupling wall19of an almost rectangular shape for connecting one end of the positive pole connecting wall17and one end of the negative pole connecting wall18. The bus bar9is formed into an almost U shape as a whole. The positive pole connecting wall17and the negative pole connecting wall18are respectively formed in an almost rectangular shape and are opposed to each other with a spacing therebetween and are parallel to each other.

The bus bars9are arranged on the respective surfaces22aof the outer side parts22as a pair (described later) of the plate10and mounted inside the bus bar accommodating part24described later. The bus bars9have their positive poles6connected to a surface of the positive pole connecting wall17opposed to the negative pole connecting wall18and negative poles7connected to a surface of the negative pole connecting wall18apart from the positive pole connecting wall17to connect the positive pole6of a battery3and the adjacent negative pole7of an adjoining battery3.

The plate10is made of an insulating synthetic resin and formed into a flat plate. As shown inFIG. 1, the plate10is laid on the top surface2aof the battery assembly2. The plate10is formed smaller than the top surface2a. The plate10includes a main body21arranged at the center of the battery assembly2, a pair of outer side parts22sandwiching the main body21therebetween, and a coupling part23for coupling the main body21to the pair of outer side parts22.

The main body21has a planar shape formed into an almost flat rectangular plate and includes electrode routing holes26for routing the positive poles6and negative poles7of the batteries3. The main body21is laid on the top surface2aof the battery assembly2in an almost center position of the battery assembly2with the positive poles6and negative poles7routed through the electrode routing holes26. The main body21includes a plurality of bus bar accommodating parts24on the surface21aexposed when the main body21is laid on the top surface2a. The plurality of bus bar accommodating parts24are formed by a plurality of bulkheads25erected from the surface21a. The main body21has bus bars8arranged in the bus bar accommodating parts24to be mounted.

The main body21includes positioning holes27allowing the positioning projections13to pass through. The positioning holes27as a pair are arranged to position at one end of the battery assembly2in one direction H when the main body21is mounted on the battery assembly2, spaced in a direction crossing the one direction H. The positioning holes27and the positioning projections13together form the positioning section, which relatively positions the battery assembly2and the plate10.

The outer side parts22as a pair are arranged parallel to the main body21and arrange therebetween the main body21. The outer side parts22as a pair respectively include a plurality of bus bar accommodating parts24on the surface22aexposed when the outer side parts are laid on the top surface2aof the battery assembly2. The plurality of bus bar accommodating parts24are formed by a plurality of bulkheads25erected from the surface22a. The outer side parts22as a pair respectively include bus bars9arranged in the bus bar accommodating parts24to be mounted.

The outer side parts22as a pair respectively include guide holes28allowing the guide projections14to pass through. A plurality of guide holes28are arranged with intervals in the one direction H, to position at both ends of the battery assembly2opposed in a direction crossing the one direction H when the pair of outer side parts22is mounted on the battery assembly2. The guide holes28and the guide projections14together form the plate displacement section, which displaces the plate10with respect to the battery assembly2in a direction in which the plurality of bus bars8,9respectively approach the corresponding positive poles6and negative poles7.

A plurality of coupling parts23are arranged between the main body21and each outer side part22, spaced in one direction H. Each of the coupling parts as a pair has one end connected to the end of the main body21in one direction H and the other end connected to the ends of the mutually opposing sides of the outer side parts22as a pair. The plurality of coupling parts23respectively couple the main body21and the pair of outer side parts22.

Each of the plurality of coupling parts23is formed into a thin crank shape and elastically deformable. Each of the plurality of coupling parts23is elastically deformed to allow the main body21and the pair of outer side parts22to be individually displaced with respect to the battery assembly2.

To assemble the power source device1of the above configuration, batteries3arranged in two rows in one direction H are sandwiched between the end plates12as a pair as shown inFIG. 1. Then, a plurality of binding bands11are passed over the top surface2aand bottom surface2bof the battery assembly2while spaced from each other. Both ends of each of the plurality of binding bands11in longitudinal direction are fixed with bolts to the pair of end plates12to bind the plurality of batteries3and integrate the battery assembly2.

Next, as shown inFIG. 1, bus bars8are arranged in the bus bar accommodating part24of the main body21to attach the bus bars8to the main body21. Bus bars9are arranged in the bus bar accommodating part24of each outer side part22to attach the bus bars9to each outer side part22. Then the bus bars8,9are attached to the plate10.

Next, as shown inFIG. 2, the plate10is positioned on the battery assembly2. The positioning projections13of one end plate12aare inserted into the positioning holes27of the main body21of the plate10to relatively position the battery assembly2and the plate10.

As shown inFIG. 4or6, the positioning projections13are further inserted into the positioning holes27to bring the plate10closer to the battery assembly2. The positive poles6and negative poles7of the batteries3of the battery assembly2are respectively inserted into the electrode routing holes26of the plate10. The guide projections14arranged on the inter-battery plate20of the battery assembly2enter the guide holes28of the plate10. In this process, the bus bars8of the main body21of the plate10, the positive pole connecting wall17and the negative pole connecting wall18, and the positive pole6and negative pole7of each battery3are arranged respectively parallel to each other.

As shown inFIGS. 3,5and7, when the guide projections14are inserted into the guide holes28, the plate10is displaced with respect to the battery assembly2in a direction in which the plurality of bus bars8,9approach the corresponding positive poles6and negative poles7. The bus bars8,9abut against the corresponding positive poles6and negative poles7.

Then, these bus bars8,9are mounted on the corresponding positive poles6and negative poles7. As shown inFIG. 2, the bus bars8,9are mounted to connect a positive pole6and a negative pole7adjacent to each other excluding the negative pole7of a battery3apositioned at one end out of the plurality of arranged batteries3and the positive pole6of a battery3bpositioned at the other end, thus connecting the batteries3of the battery assembly2in series.

Each bus bar8in the shape of a flat plate is connected while the positive pole6and the negative pole7are fixed by welding to one surface of the bus bar8parallel to one direction H. Each channel-shaped bus bar9is connected while the positive pole6abuts against the surface of the positive pole connecting wall17opposed to the negative pole connecting wall18and the negative pole7abuts against the surface of the negative pole connecting wall18apart from the positive pole connecting wall17, and the positive pole connecting wall17and the positive pole6in contact as well as the negative pole connecting wall18and the negative pole7in contact are respectively fixed and connected via welding.

The positive pole6of a battery3and the adjacent positive pole6of the negative pole7of an adjoining battery3are connected to the positive pole connecting wall17and the negative pole connecting wall18. The spacing between the surface of the positive pole connecting wall17of the bus bar9opposed to the negative pole connecting wall18and the surface of the negative pole connecting wall18apart from the positive pole connecting wall17is almost equal to the spacing between the surface on the side of the positive pole connecting part of the positive pole6and the surface on the side of the negative pole connecting part of the negative pole7. In this way, the plurality of batteries3constituting the battery assembly2are connected in series by way of bus bars8,9.

Finally, the bus bars8,9are connected via wires to a measuring part (not shown) for measuring a potential difference between the positive pole6and negative pole7of the batteries3to connect the battery assembly2and the measuring part. This completes assembly of the power source device1.

This embodiment includes positioning means for relatively positioning the battery assembly2and the plate10and plate displacement means for displacing the plate10so as to allow a plurality of bus bars8,9to respectively abut against the corresponding positive poles6and negative poles7when the plate10is mounted on the battery assembly2.

It is thus possible to readily arrange bus bars8,9in a desired position of the battery assembly2, thereby reducing the number of components for assembling the bus bars8,9to the battery assembly2and reducing the assembly man-hours. It is thus possible to reduce the number of components for assembling the power source device1and simplify the assembly work.

The positioning means includes a plurality of positioning projections13protruding from one end plate12aof the battery assembly2and a plurality of positioning holes27arranged in the plate10, each of the positioning holes27having a diameter formed larger than that of the positioning boss13. It is thus possible to position the battery assembly2and the plate10by inserting the positioning projections13into the positioning holes27. This reduces the number of components for assembling the plate10to the battery assembly2and reduces the assembly man-hours.

The plate displacement means includes a plurality of guide projections14protruding from one surface20aof the inter-battery plate20of the battery assembly2and a plurality of guide holes28arranged in the plate10into which the plurality of guide projections14are respectively inserted. The plurality of bus bars8,9are inclined in a direction respectively leaving the corresponding positive poles6and negative poles7when the guide projections14are inserted into the guide holes28as the guide projections14leave the battery assembly2.

It is thus possible to displace the plate10with respect to the battery assembly2in a direction in which the plurality of bus bars8,9respectively approach the corresponding positive poles6and negative poles7by inserting the guide projections14into the guide holes28. This allows the plurality of bus bars8,9to respectively abut against the corresponding positive poles6and negative poles7. It is this possible to readily arrange bus bars8,9in a desired position of the battery assembly2, thereby reducing the number of components for assembling the bus bars8,9to the battery assembly2and reducing the assembly man-hours.

The plate10includes a main body21and a pair of outer side parts22. The outer side parts22as a pair are respectively coupled to the main body21via elastically deformable coupling parts23, thus respectively displacing the main body21of the plate10and the pair of outer side parts22relative to the battery assembly2. This ensures that the bus bars8,9will respectively abut against the corresponding positive poles6and negative poles7, thus reliably arranging the bus bars8,9in a desired position of the battery assembly2.

While the positioning means is provided including a pair of positioning projections13having the shape of a circular cylinder and positioning holes27into which the positioning projections13are inserted, the methods for implementing positioning means and the number of positioning means are not limited in the invention. In other words, the positioning means may be implemented through a method other than projections and holes. The number of positioning means may be one or three or more. The invention does not limit the shape or number of projections and holes. Any shape and a desired number of projections and holes may be used.

While the guide projections14protrude from one surface20aof the inter-battery plate20of the battery assembly2in the above embodiment, the guide projections14may protrude from one end surface5of the plurality of batteries3of the battery assembly2in this invention.

Although the invention has been illustrated and described for the particular preferred embodiments, it is apparent to a person skilled in the art that various changes and modifications can be made on the basis of the teachings of the invention. It is apparent that such changes and modifications are within the spirit, scope, and intention of the invention as defined by the appended claims.

The present application is based on Japan Patent Application No. 2007-216715 filed on Aug. 23, 2008, the contents of which are incorporated herein for reference.