JP2018073705A - Electric power unit and vehicle including the same and manufacturing method of electric power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the strength of an end plate made of aluminum alloy.SOLUTION: In an electric power unit including multiple rectangular secondary battery cells 1, tabular end plates 3 placed on a pair of end faces, respectively, in a state where the secondary battery cells 1 are laminated, and a fastening member 4 for fastening the end plates 3, the end plates 3 are made of aluminum alloy and provided, at a part thereof, with a borehole suppression mechanism for suppressing occurrence of boreholes. With such an arrangement, occurrence of boreholes, such as cavities, is suppressed when die-casting the end plate 3 made of aluminum alloy, and since strength degradation of the end plate 3 can be circumvented, an electric power unit having improved reliability is realized.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device, a vehicle including the power supply device, and a method for manufacturing the power supply device.

  A power supply device in which a large number of secondary batteries are connected in series and in parallel is used for purposes such as driving a vehicle. An example of such a power supply device is shown in the exploded perspective view of FIG. In the power supply device shown in this figure, a large number of rectangular secondary battery cells 901 are stacked via spacers 902, an end plate 903 is disposed on an end surface, and fastened by a bind bar 904.

  The secondary battery cell expands when it is repeatedly charged and discharged. Further, expansion occurs due to deterioration of the battery. In recent years, with the increase in required battery capacity, there is a tendency for the battery to expand due to charge / discharge and deterioration, and the end plate that restrains the stack of secondary battery cells accordingly. The problem that a large load is applied is remarkable. For this reason, it is required to increase the rigidity of the end plate. On the other hand, for example, in-vehicle power supply devices are required to be reduced in weight, and conflicting characteristics such as reduction in weight and improvement in rigidity are required. For this reason, the conventional end plate is produced by die-casting an aluminum alloy (ADC12) that is relatively light and highly rigid (for example, Patent Document 1).

  However, when performing die casting of an aluminum alloy, voids and defects called castings may be formed. When heat treatment is performed to further increase the rigidity of the end plate in which the cast hole is formed, the strength of the end plate is partially reduced due to the cast hole and may be damaged. For this reason, conventionally, heat treatment cannot be performed on an end plate made of an aluminum alloy that requires strength, and as a result, the strength of the end plate cannot be increased so much.

  On the other hand, it is conceivable to increase the strength by forming the end plate by extrusion molding. However, in the case of extrusion molding, since the dimensional accuracy is not high, there is a problem that post-processing is required after the end plate is formed, and the manufacturing cost is increased.

International Publication WO2016 / 157267A1 US Patent Application Publication No. US2013 / 0189559A1

  The present invention has been made in view of such a background. An object of the present invention is to provide a power supply device in which the strength of an end plate made of an aluminum alloy is increased.

Means for Solving the Problems and Effects of the Invention

  According to the power supply device of the first embodiment of the present invention, a plurality of rectangular secondary battery cells, and a plate-like end plate respectively disposed on a pair of end surfaces in a state where the secondary battery cells are stacked. A power supply device including a fastening member for fastening the end plates to each other, wherein the end plate is made of an aluminum alloy and includes a cast hole suppressing mechanism for suppressing the generation of a cast hole in a part thereof. it can. With the above configuration, the generation of voids and other voids when die-casting an aluminum alloy end plate is suppressed, and a reduction in the strength of the end plate due to this can be avoided, and a power supply device with improved reliability is realized. The

  Moreover, according to the power supply device which concerns on a 2nd form, in addition to the said structure, the said cast hole suppression mechanism can be set as the structure formed by making the average thickness of the said end plate thin.

  Furthermore, according to the power supply device according to the third aspect, in addition to any one of the above-described configurations, the cast hole suppression mechanism is provided for inserting a bolt provided on the end plate and fixing the end plate. It can be comprised by the through-hole and the thin part which was arrange | positioned adjacent to the said through-hole, and made thickness relatively thin. With the above configuration, by forming the thin portion adjacent to the through hole, it is possible to avoid the increase in the thickness of the portion of the through hole where the load is applied, and to prevent the formation of the cast hole. Damage can be suppressed.

  Furthermore, according to the power supply device which concerns on a 4th form, in addition to any one of the said structures, a rib can be formed in the said thin part. With the above configuration, it is possible to prevent a decrease in strength by reinforcing with ribs while suppressing formation of a cast hole as a thin portion.

  Furthermore, according to the power supply device according to the fifth embodiment, a plurality of rectangular secondary battery cells, and a plate-like end plate respectively disposed on a pair of end surfaces in a state where the secondary battery cells are stacked. A power supply device including a fastening member for fastening the end plates to each other, wherein the end plate can be made of a heat-treatable alloy made of an aluminum alloy.

  Furthermore, according to the power supply device of the sixth embodiment, a plurality of rectangular secondary battery cells, and a plate-like end plate respectively disposed on a pair of end surfaces in a state where the secondary battery cells are stacked. A power supply device including a fastening member for fastening the end plates to each other, wherein the end plate is made of an aluminum alloy, and a protective layer having higher hardness than the inside can be provided on the surface thereof. With the above structure, the end plate surface made of aluminum alloy is hardened to prevent deterioration over time at the fastening part such as screwing, and the internal hardness is relatively lowered to give viscosity to the entire end plate. Stiffness can be increased.

  Furthermore, according to the power supply device which concerns on a 7th form, in addition to any one of the said structures, the said protective layer can be equipped with the corrosion resistance which prevents the corrosion of an aluminum alloy.

  Furthermore, according to the power supply device of the eighth embodiment, a plurality of rectangular secondary battery cells, and a plate-like end plate respectively disposed on a pair of end surfaces in a state where the secondary battery cells are stacked. A power supply device including a fastening member for fastening the end plates to each other, wherein the end plate is made of an aluminum alloy, and a corrosion inhibiting layer for inhibiting corrosion can be provided on the surface thereof. With the above configuration, the corrosion of the end plate surface made of aluminum alloy can be prevented by the corrosion suppression layer. In particular, aluminum alloys are excellent in thermal conductivity, and condensation is likely to occur due to a temperature difference. Since corrosion proceeds from the condensed surface, it can be effectively suppressed by protecting the most corroded surface with a corrosion inhibiting layer.

  Furthermore, according to the power supply device according to the ninth aspect, in addition to any of the above-described configurations, the end plate can be made of a heat-treated aluminum alloy. With the above-described configuration, even if the aluminum alloy end plate is heat-treated to increase the strength, the occurrence of a cast hole is suppressed.

  Furthermore, according to the power supply device which concerns on a 10th form, in addition to any one of the said structures, the said end plate can be made from die-cast aluminum alloy. With the above-described configuration, even if the aluminum alloy end plate is heat-treated to increase the strength, the occurrence of a cast hole is suppressed.

  Furthermore, according to the power supply device which concerns on an 11th form, in addition to any one of the said structures, it can utilize for the power supply device for a vehicle drive.

  Furthermore, the vehicle according to the twelfth aspect can include the power supply device according to any one of the above-described configurations.

It is a perspective view of the assembled battery concerning one embodiment of the present invention. It is a disassembled perspective view of the assembled battery shown in FIG. It is a perspective view which shows an example of an end plate. 4A is a front view of the end plate of FIG. 3, FIG. 4B is a plan view, and FIG. 4C is a side view. It is a graph which shows an example of distribution of the thickness of an end plate. It is a flowchart which shows the manufacturing method of an aluminum alloy end plate. It is a block diagram which shows the example which mounts a power supply device in the hybrid vehicle which drive | works with an engine and a motor. It is a block diagram which shows the example which mounts a power supply device in the electric vehicle which drive | works only with a motor. It is a disassembled perspective view which shows the conventional power supply device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below is an example for embodying the technical idea of the present invention, and the present invention is not limited to the following. Moreover, this specification does not specify the member shown by the claim as the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention only to specific examples unless otherwise specifically described. Only. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and reference sign indicate the same or the same members, and detailed description will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.
(Embodiment 1)

FIG. 1 is a perspective view of a power supply device 100 according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view thereof. A power supply device 100 shown in these drawings includes a battery stack 2 in which a plurality of secondary battery cells 1 are stacked, a pair of end plates 3 disposed at both ends of the battery stack 2, and a pair of end plates. 3 is provided with a pair of fastening members 4 that are connected to both ends and fasten the battery stack 2. Further, in the power supply device 100, the fastening member 4 is bent at both ends of the main body 40 disposed along the side surface of the battery stack 2 and fixed to the outer surface of the end plate 3. The fixing part 41 is provided.
(Secondary battery cell 1)

  As shown in FIG. 2, the secondary battery cell 1 is a prismatic battery that is wider than the thickness, in other words, is thinner than the width, and is stacked in the thickness direction to form a battery stack 2. The secondary battery cell 1 is a lithium ion secondary battery. However, the secondary battery cell may be any rechargeable secondary battery such as a nickel metal hydride battery or a nickel cadmium battery. The secondary battery cell 1 accommodates positive and negative electrode plates together with an electrolyte in a sealed outer can. The outer can is formed by press-molding a metal plate such as aluminum or aluminum alloy into a square shape, and the opening is hermetically sealed with a sealing plate. The sealing plate is made of the same aluminum or aluminum alloy as the outer can, and the positive and negative electrode terminals 11 are fixed to both ends. Further, the sealing plate is provided with a gas discharge valve 15 between the positive and negative electrode terminals 11.

The plurality of secondary battery cells 1 are stacked such that the thickness direction of each secondary battery cell 1 is the stacking direction to form the battery stack 2. In the secondary battery cell 1, a terminal surface 10 provided with positive and negative electrode terminals 11 is arranged on the same plane, and a plurality of secondary battery cells 1 are stacked to form a battery stack 2.
(Battery stack 2)

  As shown in FIG. 2, the battery stack 2 has insulating spacers 12 sandwiched between the secondary battery cells 1 being stacked. The insulating spacer 12 shown in the figure is made of an insulating material such as resin in the form of a thin plate or sheet. The insulating spacer 12 shown in the figure has a plate shape having a size substantially equal to the facing surface of the secondary battery cell 1, and the insulating spacer 12 is laminated between the adjacent secondary battery cells 1 so as to be adjacent to each other. The secondary battery cells 1 are insulated from each other. In addition, as a spacer arrange | positioned between the adjacent secondary battery cells 1, the spacer of the shape in which the flow path of a cooling gas is formed between the secondary battery cell 1 and a spacer can also be used. Moreover, the surface of the secondary battery cell 1 can also be coat | covered with an insulating material. For example, you may heat-weld the surface of the exterior can except the electrode part of a secondary battery cell with shrink tubes, such as PET resin. In this case, the insulating spacer may be omitted.

In the battery stack 2, a metal bus bar (not shown) is connected to the positive and negative electrode terminals 11 of adjacent secondary battery cells 1, and a plurality of secondary battery cells 1 are connected in series or in parallel with the bus bar. Alternatively, they are connected in series and in parallel. The battery stack 2 shown in the figure has twelve secondary battery cells 1 connected in series. However, the present invention does not specify the number of secondary battery cells 1 constituting the battery stack and the connection state thereof.
(End face spacer 13)

  In the battery stack 2, end plates 3 are arranged with end face spacers 13 sandwiched between both end faces. As shown in FIG. 2, the end surface spacer 13 is disposed between the battery stack 2 and the end plate 3 to insulate the end plate 3 from the battery stack 2. The end face spacer 13 is made of an insulating material such as resin and is manufactured in a thin plate shape or sheet shape. The end surface spacer 13 shown in the drawing includes a plate portion 13X having a size capable of covering the entire facing surface of the secondary battery cell 1, and the secondary battery cell in which the plate portion 13X is disposed at both ends of the battery stack 2. 1 and the end plate 3 are stacked.

Furthermore, the end surface spacer 13 of FIG. 2 is provided with a terminal surface cover portion 13A that covers the terminal surface 10 of the secondary battery cell 1 connected to the upper end edge of the plate portion 13X. The end surface spacer 13 of FIG. 2 is provided with a terminal surface cover portion 13A that protrudes toward the secondary battery cell 1 over the entire upper end edge of the plate portion 13X. As described above, the structure in which the terminal surface cover portion 13A is provided over the entire upper end edge of the plate portion 13X has a terminal which is the upper surface of the secondary battery cell 1 while ensuring an insulation distance between the end plate 3 and the battery stack 2. The insulating property can be improved by reliably covering the surface 10.
(End plate 3)

  As shown in FIGS. 1 and 2, the end plate 3 is disposed at both ends of the battery stack 2 and is fastened via fastening members 4 disposed along both side surfaces of the battery stack 2. The end plates 3 are arranged at both ends of the battery stack 2 in the stacking direction of the secondary battery cells 1 and outside the end face spacer 13 to sandwich the battery stack 2 from both ends. The end plate 3 is made of an aluminum alloy. Aluminum alloys include Al-Cu-Mg, Al-Cu-Ni-Mg, Al-Cu-Si, Al-Si-Mg, Al-Si-Cu, Al-Si-Cu-Mg Al-Si-Cu-Ni-Mg and the like can be used. The end plate 3 made of aluminum alloy is a heat treatment type alloy. The end plate 3 made of aluminum alloy is molded by die casting as will be described later. Moreover, it is preferable that the end plate 3 made of an aluminum alloy is tempered by heat treatment including solution treatment, quenching, aging heat treatment, and the like, as will be described later.

  The end plate 3 has a quadrangular outer shape and is disposed so as to face the end surface of the battery stack 2. The end plate 3 shown in FIGS. 1 and 2 has an outer shape substantially equal to the outer shape of the secondary battery cell 1. In other words, the end plate 3 shown in the drawing has a horizontal width equal to the width of the secondary battery cell 1 and a vertical height equal to the height of the secondary battery cell 1. In the present specification, the vertical direction is the vertical direction in the figure, and the horizontal direction is the horizontal direction in the figure and means a horizontal direction perpendicular to the stacking direction of the batteries.

  Further, the end plate 3 shown in FIG. 2 has a plurality of through holes for fixing the end plate 3. For example, the end plate 3 has a first through hole 33 for inserting the fastener 19 for fixing the fixing portion 41 of the fastening member 4. The end plate 3 shown in the figure has a plurality of through holes as the first through holes 33. The end plate 3 shown in the drawing is provided with a plurality of first through holes 33 that are spaced apart from each other at positions opposite to the fixed portion 41 on both sides. The end plate 3 in FIG. 2 is provided with six first through holes 33 in total, three along each side. In the end plate 3, the fastener 19 that penetrates the fixing portion 41 disposed on the outer peripheral surface is inserted into the first through hole 33. The fastener 19 inserted into the first through hole 33 is fixed to the first through hole 33 to fix the fixing portion 41 at a fixed position.

Further, the end plate 3 has a second through hole 34 different from the first through hole 33 and has a through hole for inserting a bolt for fixing the power supply device to a fixing portion (for example, a vehicle in a vehicle-mounted power supply device). Forming. The second through holes 34 are penetrated as vertical holes at both ends on the upper surface of the end plate 3.
(Fastener 19)

The fastener 19 is fixed to the first through hole 33 so as not to come off. As such a fastener 19, a set screw, a bolt, a rivet or the like can be used. When a fastener such as a set screw or a bolt is inserted into the first through hole 33, the fastener is screwed into the first through hole 33 and fixed. Therefore, the first through-hole 33 to which the fastener, which is a set screw or a bolt, is fixed can be provided with a female screw that meshes with the set screw or the male screw of the bolt on the inner surface. In addition, the fastener that is a rivet is inserted into the first through hole 33 of the end plate 3 in a state of passing through the fixing portion, and one end thereof is caulked inside the first through hole 33 to thereby fix the end plate 3 and the fixing portion. And fix. The fastener, which is a rivet, sandwiches the first through hole 33 of the end plate 3 and the opening edge of the through hole of the fixed portion by a caulking portion formed inside the first through hole 33 of the end plate 3. Then, the fixing portion is fixed to the end plate 3. The first through-hole 33 into which the rivet is inserted has an inner shape in which the opening area of the outer surface is reduced so that it cannot pass through the head of the rivet, and the opening area on the opposite surface side, which is the opposite side, is increased. It can be set as the structure which can arrange | position the crimping part formed by deform | transforming inside.
(Fastening member 4)

  As shown in FIGS. 1 and 2, the fastening member 4 is extended in the stacking direction of the battery stack 2, and both ends are fixed to end plates 3 arranged on both end faces of the battery stack 2, The battery stack 2 is fastened in the stacking direction via the end plate 3. The fastening member 4 is a metal plate having a predetermined width and a predetermined thickness along the side surface of the battery stack 2, and is disposed to face both side surfaces of the battery stack 2. The fastening member 4 can be a metal plate such as iron, preferably a steel plate. The fastening member 4 made of a metal plate is bent into a predetermined shape by press molding or the like.

  The fastening member 4 includes a main body portion 40 arranged along the side surface of the battery stack 2, and a fixing portion 41 that is bent at both ends of the main body portion 40 and fixed to the outer surface of the end plate 3. ing. The main body 40 has a rectangular shape with a size that covers almost the entire battery stack 2 and the end plates 3 disposed at both ends thereof. The main body 40 shown in FIG. 1 covers almost the entire side surface of the battery stack 2 without any gaps. However, the main body 40 can also be provided with one or more openings to expose part of the side surface of the battery stack. In order to fix both ends to the pair of end plates 3, the fastening member 4 is provided with a fixing portion 41 by bending both end portions along the outer surface of the end plate 3. The fixing portion 41 shown in the figure is substantially equal to the height of the main body portion 40 and the end plate 3 in the vertical direction and covers the left and right side portions of the end plate 3. The fastening member 4 is fixed to the end plate 3 via a fastener 19 inserted in a through hole 42 provided at the tip of the fixing portion 41. Furthermore, the fastening member 4 shown in the drawing includes a bent portion 44 that holds the upper surface and the lower surface of the battery stack 2 along the upper end portion of the intermediate portion excluding both end portions of the main body portion 40. The bent portion 44 holds the upper and lower surfaces of the secondary battery cells 1 constituting the battery stack 2 and suppresses the position of the terminal surface 10 of each secondary battery cell 1 from shifting up and down.

In addition, although the fastening member 4 is not shown in figure, an insulating sheet is arrange | positioned on the inner surface of the main-body part 40 and the bending part 44, and the secondary battery cell 1 and the fastening member 4 of the battery laminated body 2 are connected with this insulating sheet. Can be insulated. Furthermore, although not shown, the fastening member 4 can also protect the both side surfaces of the end plate 3 from shocks such as vibration by disposing buffer materials on the inner surfaces of both end portions of the main body 40.
(Cavity control mechanism)

An example of the end plate 3 is shown in a perspective view of FIG. 3, a front view of FIG. 4A, a plan view of FIG. 4B, and a side view of FIG. 4C. The end plate 3 shown in these drawings is partially provided with a cast hole suppressing mechanism for suppressing the occurrence of a cast hole. The cast hole suppression mechanism is a mechanism for suppressing the formation of voids or the like when die-casting the end plate 3 made of aluminum alloy. As such a cast hole suppression mechanism, for example, the average thickness of the end plate 3 is reduced. That is, if there is a thick part during the molding of the end plate, voids and defects are likely to be formed. Therefore, gaps and depressions are formed so that the thickness of the end plate does not increase. At this time, by using a through hole for fixing the end plate 3 and forming the through hole, the end plate 3 is partially thinned, and the formation of the through hole for fixing and the cast hole suppressing mechanism are common. Can be
(Solid area 31)

  In the example shown in FIG. 3 and FIGS. 4A to 4C, solid regions 31 are formed on both sides of the end plate 3, respectively. Yes. The pair of solid area 31 and intermediate area 32 are integrally molded. Each solid region 31 forms a second through hole 34 penetrating in the vertical direction on the edge side. Further, a plurality of first through holes 33 penetrating in the horizontal direction are formed on the side facing the intermediate region 32 so as to be separated in the vertical direction. In the example of FIGS. 3 and 4A, the first through holes 33 are formed at three positions so as to be arranged in a straight line at equal intervals in each solid region 31. Thereby, the edge side of the solid region 31 is the second through hole 34, and the side facing the intermediate region 32 is the first through hole 33, avoiding the continuous existence of thick parts, and casting. Nest generation is suppressed.

Furthermore, the solid area 31 may be partially cut out or cut out to further reduce the thick part. In the example of FIGS. 3 and 4A, a window portion 35 cut out in a rectangular shape is formed in the middle of the edge side. By providing such an additional notch portion, the occurrence of a cast hole can be further suppressed. In addition, the weight of the end plate 3 and the material cost can be reduced.
(Intermediate region 32)

  On the other hand, a rib 37 for reinforcement can be formed while the intermediate region 32 connecting the separated solid portions is a plate-like thin portion 36 thinner than the solid region 31. By doing in this way, intensity | strength can be exhibited by providing the rib 37 partially, avoiding that an intermediate part becomes thick. The ribs 37 are preferably formed so as to intersect in a cross shape or an X shape. In the example of FIGS. 3 and 4A, one vertical rib 37a substantially parallel to the solid region 31 and three horizontal ribs 37b substantially orthogonal to the vertical rib 37a are provided. The thicknesses of the vertical ribs 37a and the horizontal ribs 37b are substantially equal to the thickness of the solid region 31. Moreover, in order to provide a screw hole etc., you may form one part rib thickly. In the example of FIGS. 3 and 4A, the uppermost horizontal rib 37c is formed to be thicker than the other horizontal ribs 37b, and a screw hole 38a and a notch 38b opened on the end face side are formed. Furthermore, a fitting hole 39 for fitting with the end face spacer 13 is formed on the upper surface side. By forming the fitting hole 39, the screw hole 38a, and the notch 38b as described above, it becomes possible to reduce the thickness portion of the end plate 3 and suppress the occurrence of the cast hole, and as a cast hole suppressing mechanism. Can function. The fitting hole 39 has a shape and size capable of fitting the fitting portion provided in the end face spacer 13 and is formed in a portion corresponding to the fitting portion.

  As described above, the cast hole suppressing mechanism is achieved by reducing the thickness portion of the end plate 3 as much as possible. On the other hand, if the thickness of the end plate is reduced as a whole, the strength of the end plate is lowered accordingly. Therefore, the strength of the end plate is contradictory to the suppression of the cast hole. Therefore, in this embodiment, the thickness of the end plate is not reduced in order to suppress the cast hole while maintaining the decrease in the strength of the end plate. The through-hole and the thin part are provided so as to avoid the thick part, in other words, the solid part continuously existing in a lump shape. Further, by providing ribs in the thin portion, it is possible to suppress the occurrence of a cast hole while avoiding a decrease in the strength of the end plate. Further, by suppressing the generation of the cast hole, it becomes possible to perform the heat treatment described later on the end plate made of aluminum alloy, and the proof stress of the end plate can be further improved.

From another point of view, in order to prevent the thickness portion of the end plate from continuing, the standard deviation of the thickness distribution of the end plate is 30 or less as shown in the graph showing the thickness distribution of the end plate in FIG. It is preferable that
(End plate manufacturing method)

  Next, the manufacturing method which forms the end plate made from an aluminum alloy by die-casting is demonstrated based on the flowchart of FIG. First, the shape of the end plate is designed in advance, and a mold corresponding to this is designed. Specifically, as described above, the shape of the end plate provided with a cast hole suppressing mechanism that suppresses the occurrence of a cast hole is selected in advance, and a die casting die corresponding to this is made of special steel or the like. In such a prepared state, die casting is performed in step S1. Here, a molten aluminum alloy is pressed into a mold by pressure.

  Next, in step S2, solution treatment is performed. Here, in order to make the aluminum alloy uniform at a high temperature, the aluminum alloy is held at a predetermined temperature for a certain time. Depending on the heating rate until reaching a certain temperature, the time until it becomes a uniform solid solution varies.

  Further, in step S3, quenching is performed. Quenching is a process in which an aluminum alloy that has become a uniform solid solution is cooled from a high temperature at a speed that does not allow time for movement or diffusion of atoms. It is an alloy that remains highly soluble at room temperature (an alloy that is more than the solid solubility limit), and such a state is called a supersaturated solid solution. Although it is important to increase the cooling rate, on the other hand, rapid cooling may cause thermal distortion, dimensional change, etc., and therefore, treatment such as oil quenching or quenching in boiling water is performed.

Finally, an aging heat treatment is performed in step S4. Aging is a phenomenon in which properties change over time. Aging at room temperature or room temperature is called normal aging or natural aging. When heated and held at a temperature above room temperature, it is called high temperature aging, artificial aging, tempering aging, or the like. Aging changes the internal structure of the aluminum alloy. In particular, the hardness and strength are increased by age hardening. Age hardening is attributed to the formation of precipitates and is thought to be due to the interaction between the microscopic structure (nanoprecipitation phase) formed by precipitation and dislocations.
(Embodiment 2)

  Furthermore, a protective layer having higher hardness than the inside can be provided on the surface of the end plate made of aluminum alloy by the above heat treatment. By doing so, the internal plate is made brittle by making the internal hardness relatively low while preventing aging deterioration at the fastening part such as screwing formed on the surface of the end plate. Can be increased. In other words, if the overall hardness is increased, it becomes brittle and may be damaged by an external impact. Therefore, while maintaining a protective layer with increased surface area hardness, the inside should be intentionally suppressed. It is possible to increase the viscosity and improve the impact resistance.

  Further, by providing a protective layer over the entire surface of the end plate, for example, it is possible to suppress the wear of the thread provided in the through hole, and to increase the tightening torque at the time of screwing. It can contribute to the improvement of sex.

  Further, by providing a protective layer, the bending strength is increased, and even when a load is applied due to the expansion of the secondary battery cell 1 sandwiched between the end plates, the surface portion is deformed to cause a crack and break. Can be suppressed.

  The protective layer only needs to have a region with high hardness on the surface of the aluminum alloy end plate, and does not require a clear boundary line for distinguishing the protective layer from other portions. That is, it includes a state in which a region having high hardness is formed on the surface of the aluminum alloy by the heat treatment described above.

It is also preferred that the protective layer has corrosion resistance that prevents corrosion of the aluminum alloy. Thereby, the end plate excellent in resistance to aging can be configured.
(Embodiment 3)

  Furthermore, a corrosion inhibiting layer for inhibiting corrosion can be provided on the surface of the end plate made of aluminum alloy. In particular, aluminum alloys are excellent in thermal conductivity, and condensation is likely to occur due to a temperature difference. Since corrosion proceeds from the condensed surface, it can be effectively suppressed by protecting the most corroded surface with a corrosion inhibiting layer. The restraint member 4 that contacts the end plate 3 is often made of steel, but by protecting the surface of the end plate 3 with a corrosion-inhibiting layer, ionization between different metals is suppressed, and the end plate 3 3 corrosion can be effectively prevented.

  Thus, it can contribute to weight reduction and rigidity improvement of the end plate. As a result, it is possible to avoid a decrease in the strength of the end plate and to realize a power supply device with improved reliability.

The above power supply apparatus can be used as a vehicle-mounted power supply. As a vehicle equipped with a power supply device, an electric vehicle such as a hybrid vehicle or a plug-in hybrid vehicle that runs with both an engine and a motor, or an electric vehicle that runs only with a motor can be used, and it is used as a power source for these vehicles. . In order to obtain electric power for driving the vehicle, an example will be described in which a large-capacity, high-output power supply device 100 is constructed by connecting a large number of the above-described power supply devices in series or in parallel and further adding necessary control circuits. .
(Power supply for hybrid vehicles)

FIG. 7 shows an example in which a power supply device is mounted on a hybrid vehicle that runs with both an engine and a motor. A vehicle HV equipped with the power supply device shown in this figure includes a vehicle main body 91, an engine 96 that travels the vehicle main body 91, and a travel motor 93, and wheels that are driven by the engine 96 and the travel motor 93. 97, a power supply device 100 that supplies power to the motor 93, and a generator 94 that charges a battery of the power supply device 100. The power supply apparatus 100 is connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The vehicle HV travels by both the motor 93 and the engine 96 while charging / discharging the battery of the power supply device 100. The motor 93 is driven to drive the vehicle when the engine efficiency is low, for example, during acceleration or low-speed driving. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by the engine 96 or is driven by regenerative braking when the vehicle is braked to charge the battery of the power supply device 100.
(Power supply for electric vehicles)

  FIG. 8 shows an example in which a power supply device is mounted on an electric vehicle that runs only with a motor. A vehicle EV equipped with the power supply device shown in this figure includes a traveling motor 93 for traveling the vehicle EV, a power supply device 100 that supplies power to the motor 93, and a generator 94 that charges a battery of the power supply device 100. And. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by energy when regeneratively braking the vehicle EV and charges the battery of the power supply device 100.

  A power supply apparatus according to the present invention, a vehicle including the power supply apparatus, and a method for manufacturing the power supply apparatus are provided as a power supply apparatus for a plug-in hybrid electric vehicle, a hybrid electric vehicle, an electric vehicle, or the like that can switch between an EV traveling mode and an HEV traveling mode. It can be suitably used. Also, a backup power supply device that can be mounted on a rack of a computer server, a backup power supply device for a wireless base station such as a mobile phone, a power storage device for home use and a factory, a power supply for a street light, etc. Also, it can be used as appropriate for applications such as a backup power source such as a traffic light.

DESCRIPTION OF SYMBOLS 1 ... Secondary battery cell 2 ... Battery laminated body 3 ... End plate 4 ... Fastening member 10 ... Terminal surface 11 ... Electrode terminal 12 ... Insulating spacer 13 ... End surface spacer 13X ... Plate part 13A ... Terminal surface cover part 15 ... Gas exhaust valve 19 ... Fastener 31 ... Solid region 32 ... Intermediate region 33 ... First through hole 34 ... Second through hole 35 ... Window portion 36 ... Thin portion 37 ... Rib; 37a ... Vertical rib; 37b ... Lateral rib; Upper lateral rib 38a ... screw hole; 38b ... notch 39 ... fitting hole 40 ... main body 41 ... fixing part 42 ... through hole 44 ... bent part 91 ... vehicle main body 93 ... motor 94 ... generator 95 ... DC / AC inverter 96 ... engine 97 ... wheel 100 ... power supply device 901 ... secondary battery cell 902 ... spacer 903 ... end plate 904 ... bind bar HV ... vehicle EV ... vehicle

Claims (12)

A plurality of rectangular secondary battery cells;
In the state where the secondary battery cells are stacked, a plate-shaped end plate disposed on each of a pair of end surfaces;
A power supply device comprising a fastening member for fastening the end plates together,
The end plate is made of an aluminum alloy, and a power supply device including a cast hole suppressing mechanism for suppressing generation of a cast hole in a part thereof. The power supply device according to claim 1,
The power supply device, wherein the cast hole suppression mechanism is configured to reduce an average thickness of the end plate. The power supply device according to claim 1 or 2,
The cast hole suppression mechanism is provided on the end plate,
A through hole for inserting a bolt for fixing the end plate;
A power supply device comprising a thin portion having a relatively thin wall thickness disposed adjacent to the through hole. The power supply device according to claim 3,
A power supply device in which a rib is formed on the thin portion. A plurality of rectangular secondary battery cells;
In the state where the secondary battery cells are stacked, a plate-shaped end plate disposed on each of a pair of end surfaces;
A power supply device comprising a fastening member for fastening the end plates together,
The said end plate is a power supply device comprised by the heat processing type alloy made from an aluminum alloy. A plurality of rectangular secondary battery cells;
In the state where the secondary battery cells are stacked, a plate-shaped end plate disposed on each of a pair of end surfaces;
A power supply device comprising a fastening member for fastening the end plates together,
The end plate is made of an aluminum alloy, and a power supply device in which a protective layer having a higher hardness than the inside is provided on the surface of the end plate. The power supply device according to claim 6,
The power supply apparatus in which the said protective layer is equipped with the corrosion resistance which prevents the corrosion of an aluminum alloy. A plurality of rectangular secondary battery cells;
In the state where the secondary battery cells are stacked, a plate-shaped end plate disposed on each of a pair of end surfaces;
A power supply device comprising a fastening member for fastening the end plates together,
The said end plate is an aluminum alloy, The power supply device which provides the corrosion suppression layer for suppressing corrosion on the surface. It is a power supply device as described in any one of Claims 1-8,
A power supply device in which the end plate is made of a heat-treated aluminum alloy. The power supply device according to any one of claims 1 to 9,
The power supply device in which the end plate is made of a die-cast aluminum alloy. It is a power supply device as described in any one of Claims 1-10,
A power supply device that is a power supply device for driving a vehicle.   A vehicle comprising the power supply device according to any one of claims 1 to 11.

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