JP2011034821A - Power storage module and hybrid type working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power storage module with increased impact resistance. <P>SOLUTION: The laminated body includes a plurality of power storage cells laminated in thickness direction and at least one heat radiation plate inserted between the power storage cells. The power storage cells has a shape of plate shape in which the power storage element is enveloped by a film. When the power storage cells are viewed in parallel line in the thickness direction, the edge of the heat radiation plate overhangs to the outside of the edge of the power storage cells, and at least one through-hole is formed in a region overhung of the heat radiation plate. A pair of pressing plates are arranged at both ends of the laminated body, and a plurality of tie-rods connect the pair of pressing plates and add a compression force in lamination direction to the laminated body. At least one tie-rod passes through the through-hole of the heat radiation plate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power storage module and a hybrid work machine using the same.

  Development of hybrid type automobiles and hybrid type work machines using storage cells such as rechargeable secondary batteries and capacitors has been promoted. 2. Description of the Related Art A flat (plate-shaped) power storage cell (battery pack) in which a power storage element is wrapped with a film has been proposed as a power storage cell employed in a hybrid vehicle or a hybrid work machine. A positive electrode terminal and a negative electrode terminal are led out from the outer periphery of the storage cell.

  A power storage module in which a plurality of power storage cells are electrically connected is obtained by stacking a plurality of power storage cells and passing tie rods through through holes provided in the positive electrode terminal and the negative electrode terminal (Patent Document 1). .

US Patent Publication No. 2007/0207349 A1

  When vibration or impact is applied to the power storage module, the joint portion between the tie rod and the positive electrode terminal or the negative electrode terminal may be damaged. In addition, a resin is used for the film that wraps the power storage element. For this reason, when an electrical storage cell is hold | maintained at the edge of a film, a film may be damaged by a vibration or an impact.

  An object of the present invention is to provide a power storage module with improved impact resistance. Another object of the present invention is to provide a hybrid work machine to which the power storage module is applied.

According to one aspect of the invention,
A plurality of power storage cells having a plate-like shape in which a power storage element is wrapped with a film and stacked in the thickness direction; and at least one heat dissipation plate inserted between the power storage cells, the thickness of the power storage cell When viewed from a line of sight parallel to the vertical direction, an edge of the heat sink extends beyond the edge of the storage cell, and at least one through hole is formed in the extended area of the heat sink Body,
A pair of pressing plates disposed at both ends of the laminate;
A plurality of tie rods that connect the pair of pressing plates and apply a compressive force in the stacking direction to the stacked body;
At least one tie rod is provided with a power storage module passing through the through hole of the heat sink.

  According to another aspect of the present invention, a hybrid work machine to which the above-described power storage module is applied is provided.

  The storage cell is held by a frictional force generated by a compressive force applied to the stacked body. For this reason, destruction of a film or an electrode terminal can be suppressed. Further, by passing the tie rod through the through hole of the heat sink, a part of the shearing force generated in the laminated body is dispersed in the tie rod. Thereby, the shift | offset | difference of an electrical storage cell and a heat sink can be suppressed.

(1A) is a cross-sectional view of the power storage module according to the embodiment, (1B) is a cross-sectional view taken along one-dot chain line 1B-1B in (1A), and (1C) is one-dot chain line 1C-1C in (1B). FIG. (2A) is a cross-sectional view of a power storage module according to a reference example, (2B) is a diagram showing a beam structure that models the power storage module of (2A), and (2C) is a shear force generated in the beam. It is a graph which shows distribution of. (3A) is a cross-sectional view of the power storage module according to the embodiment, (3B) is a diagram showing a beam structure that models the power storage module of (3A), and (3C) is a shear force generated in the beam. It is a graph which shows distribution of. (4A) and (4B) are diagrams showing a beam structure that models the power storage module according to the embodiment. It is a graph which shows the simulation result of the shear force which generate | occur | produces in the beam structure of the model shown in FIG. (6A)-(6C) are sectional views of the joint portion between the heat dissipation plate and the tie rod of the power storage module according to the embodiment, and (6D) is a plan view of an opening provided in the heat dissipation plate. It is an example of sectional drawing of the electrical storage apparatus carrying the electrical storage module by an Example. It is another example of sectional drawing of the electrical storage apparatus carrying the electrical storage module by an Example. It is another example of sectional drawing of the electrical storage apparatus carrying the electrical storage module by an Example. It is a schematic plan view of the hybrid type work machine carrying the electrical storage module by an Example.

  FIG. 1A shows a cross-sectional view of a power storage module according to an embodiment. The pressing plates 31 are in close contact with both ends of the laminated body 30 in which the flat (plate-shaped) storage cells 20 and the heat dissipation plates 25 are alternately stacked. A plurality of tie rods 33 connect the two pressing plates 31 and apply a compressive force in the stacking direction to the stacked body 30. A through hole 26 is formed in each of the heat radiating plates 25. The tie rod 33 passes through the through hole 26.

  The relative positions of the tie rod 33 and the heat sink 25 are constrained with respect to the direction orthogonal to the stacking direction of the storage cells 20. Note that a gap of, for example, about 0.1 mm may be secured between the outer peripheral surface of the tie rod 33 and the inner peripheral surface of the through hole 26. In this case, the variation of the relative position between the tie rod 33 and the heat sink 25 is allowed within a range of ± 0.1 mm, but the variation beyond that is prohibited.

  Each of the electricity storage cells 20 is formed by sandwiching a flat electricity storage element such as a secondary battery or an electric double layer capacitor between a pair of laminate films. The electricity storage cell 20 includes a region (fused portion) where the laminate films are fused to each other on the outer peripheral portion thereof. The storage cell 20 includes a pair of electrode terminals 21. The electrode terminals 21 are led out from the outer peripheral portions of the storage cells 20 facing each other. One of the electrode terminals 21 is a positive electrode, and the other is a negative electrode. A plurality of power storage cells 20 are connected in series by connecting the electrode terminals 21 of the power storage cells 20 adjacent to each other.

  For example, aluminum is used for the heat radiating plate 25, and stainless steel is used for the tie rod 33 and the pressing plate 31, for example.

  FIG. 1B is a cross-sectional view taken along one-dot chain line 1B-1B in FIG. 1A. The planar shape of the storage cell 20 is substantially rectangular. The electrode terminal 21 is led out from the mutually opposing sides (upper side and lower side in FIG. 1B). The heat radiating plate 25 protrudes beyond the edge of the storage cell 20 in plan view. The tip of the electrode terminal 21 extends slightly outside the edge of the heat sink 25.

  As an example, the heat sink 25 includes a region 25a that overlaps the storage cell 20, two regions 25b that protrude from the region 25a in a lateral direction (a direction perpendicular to the direction connecting the electrode terminals 21), and a vertical direction from these regions 25b. It includes four regions 25c protruding in the direction. The region 25c enters inward from the edge of the storage cell 20 in the lateral direction. That is, the region 25c and the storage cell 20 partially overlap in the lateral direction.

  The through hole 26 is arranged in a region 25 b or 25 c of the heat radiating plate 25 that protrudes from the storage cell 20. A tie rod 33 is disposed in the through hole 26. By forcibly air-cooling the regions 25b and 25c protruding from the storage cell 20, the efficiency of heat dissipation can be increased. It is preferable to arrange the through hole 26 and the tie rod 33 so that the tie rod 33 does not hinder forced air-cooled airflow. For example, in FIG. 1B, the storage cell 21 and the tie rod 33 are arranged so that the storage cell 21 and the tie rod 33 overlap at least partially in the lateral direction (the direction orthogonal to the direction connecting the pair of electrode terminals 21). It is preferable.

  FIG. 1C shows a part of a cross section taken along one-dot chain line 1C-1C in FIG. 1B. Electrode terminals 21 are led out from both ends of the storage cell 20, respectively. The heat dissipation plates 25 are in close contact with both surfaces of the storage cell 20.

  The storage cell 20 is supported between the pair of pressing plates 31 by the frictional force generated on the contact surface between the storage cell 20 and the heat dissipation plate 25. Since the fused portion of the film surrounding the storage cell 20 and the electrode terminal 21 do not contribute to the mechanical support of the storage cell 20, damage to the electrode terminal 21 and the film due to vibration or impact can be prevented.

  FIG. 2A shows a cross-sectional view of a power storage module according to a reference example. In the reference example, the heat sink 25 is removed from the power storage module according to the embodiment shown in FIG. 1A. For this reason, the storage cells 20 are in direct contact with each other. Other configurations are the same as those of the power storage module shown in FIG. 1A. A laminated body composed of a plurality of storage cells 20 held by frictional force can be considered as one beam supported at both ends.

  FIG. 2B shows a beam that models the stacked body of the storage cells 20. An xyz orthogonal coordinate system is defined in which the length direction of the beam is x and the vertically upward direction is the positive direction of the z axis. Consider the behavior when a vertical downward impact load is applied to this beam.

The friction coefficient of the contact surface of the storage cell 20 is set to 0.2. This value is an actual measurement value of a storage cell covered with a laminate film. The vertical stress (surface pressure) applied to the storage cell 20 is 5 kgf / cm ² . This value is determined from the design specifications of the storage cell 20. The area of the contact surface of the electrical storage cell 20 is 15 × 15 = 225 cm ² . At this time, the maximum value Fmax of the frictional force generated on the contact surface of the storage cell 20 is 0.2 × 225 × 5 = 225 kgf.

  FIG. 2C shows the distribution of the shearing force in the x direction when a vertically downward impact load is applied to the beam. In FIG. 2B, a shear force that causes a downward-shearing shear deformation is defined as positive. The magnitude of the shear force acting on the left and right contact surfaces is maximized. Let the maximum value of the shearing force be Fs.

  Assume that each power storage cell 20 has a weight of 0.6 kg and 18 power storage cells 20 are stacked. The 18 storage cells weigh 10.8 kg. When the impact acceleration α is 100 G (corresponding to JIS C0041), the maximum shearing force value Fs is (10.8 × α) / 2 = 540 kgf.

  Since the maximum value Fs of the shearing force is equal to or greater than the maximum value Fmax of the frictional force, the storage cell 20 is displaced when an impact of impact acceleration 100G is applied to the storage module shown in FIG. 2A. In addition, when the impact load is large, the storage cell 20 may be dissipated.

  FIG. 3A shows a cross-sectional view of the power storage module according to the embodiment. This is the same as shown in FIG. 1A. It is assumed that the tie rod 33 is a completely rigid body, and the relative position between the heat sink 25 and the tie rod 33 is fixed with respect to the direction orthogonal to the stacking direction. When the laminated body 30 is considered as one beam, the position where the heat sink 25 is arranged becomes a fulcrum.

  FIG. 3B shows a beam that models the stacked body 30 shown in FIG. 3A. The position of the heat sink 25 is a beam fulcrum.

  FIG. 3C shows the distribution of the shearing force in the x direction when a vertically downward impact load is applied to the laminate 30. In FIG. 3B, a shearing force that causes a downward-shearing shear deformation is defined as positive. The friction coefficient of the contact surface between the storage cell 20 and the heat sink 25 is set to 0.2. This is an actual measurement value. Other conditions are the same as those in the evaluation of FIGS. 2A to 2C. At this time, the maximum value Fmax of the frictional force is 225 kgf.

  When a vertical downward impact load corresponding to an impact acceleration α of 100 G is applied, the shear force Fs generated on the contact surface between the storage cell 20 and the heat sink 25 is (0.6 × 100) / 2 = 30 kgf. Become.

  Since the maximum value Fmax of the frictional force is greater than the shearing force Fs, no deviation occurs in the storage cell 20. It can be seen that the storage cell 20 is stably held even when an impact load corresponding to an impact acceleration α of 100 G is applied.

  3A to 3C, it is assumed that the tie rod 33 is a completely rigid body. Next, a case where the tie rod 33 is not a complete rigid body will be described. When the tie rod 33 is not a perfect rigid body, when an impact load is applied, the tie rod 33 bends.

  FIG. 4A shows a simulation model when the tie rod 33 is not a complete rigid body. The four tie rods 33 can be represented by one beam 33A, and the stacked body 30 of the storage cell 20 and the heat sink 25 can be represented by another one beam 30A. The heat radiating plate 25 can be considered as a truss 25A for pin-joining the beam 33A and the beam 30A. The beam 33A is supported at both ends thereof.

  FIG. 4B shows a state in which a load is applied to the beam 33A and the beam 30A and the beam is bent. In the two-dimensional beam, when the axial force terms (axial compressive force and tensile force) are ignored, the member stiffness matrix is expressed by the following determinant.

Here, E is the Young's modulus (longitudinal elastic modulus) of the beam, I is the moment of inertia of the cross section of the beam, L is the total length of the beam, φ is the shear deformation term, δ _v is the deflection term, θ is the deflection angle, and Ps is the shear Force, Pm is a bending moment, G is a transverse elastic modulus of the beam, k is a coefficient by which the cross-sectional area against shear deformation is multiplied, and A is a cross-sectional area of the beam.

  Focusing on the center of the beam of length L, since the deflection angle θ is 0, the determinant (1) is expressed as follows.

For overlapped beams shown in FIG. 4B, in the one beam 30A, and the other beam 33A, Equation (2) holds the above, both the amount of deflection [delta] _v are identical. Therefore, a shearing force Ps ₁ acting on the beam 30A, a shear force Ps ₂ acting on the beam 33A is expressed by the following equation.

Here, φ ₁ is the shear deformation term of the beam 30A by the storage cell 20, E ₁ I ₁ is the rigidity of the beam 30A, G ₁ is the transverse elastic coefficient of the beam 30A, and k ₁ is a coefficient by which the cross-sectional area for shear deformation is multiplied. k ₁ = 0.833, _{a 1} is the cross-sectional area of the beam 30A. φ ₂ is a shear deformation term of the beam 33A by the tie rod 33, E ₂ I ₂ is the rigidity of the beam 33A, G ₂ is a transverse elastic coefficient of the beam 33A, k ₂ is a coefficient by which the cross-sectional area against the shear deformation is multiplied, and k ₂ = 0 .900, _{a 2} is the cross-sectional area of the beam 33A. L is the total length of the beam 30A and Li 33A, [delta] _v is the amount of deflection of the beam 30A and the beam 33A.

  Since the entire stiffness matrix is the sum of the beam 30A and the beam 33A, the following equation is established.

  The shearing force on the left side of the above equation (4) is equal to the reaction force R = w × (L / 2) at both ends of the laminated beam. Here, w is a uniformly distributed load. Therefore, equation (4) is modified as follows.

When the deflection amount [delta] _v is substituted in equation (3), the shear force Ps ₁ and Ps ₂ is calculated. Table 1 shows the preconditions for calculating the shear force and the calculation results. The unit of force is kgf, and the unit of length is cm. The total length L of the beam 30A is 1.43 × 18 + 0.1 × 17 = 27.44 cm. The mass of the storage cell 20 was 0.6 kg, the number of storage cells 20 was 18, the thickness of the storage cell 20 was 1.43 cm, the thickness of the heat sink 25 was 0.1 cm, and the impact acceleration was 100 G. At this time, the equally distributed load w is (0.6 × 18 × 100) /27.54=39.216 kgf / cm.

The shearing force Ps generated at both ends of the beam 30A is 152.3 kgf. It can be seen that the shear force of the example of FIGS. 4A to 4B is about 28% of the shear force of 540 kgf of the reference example shown in FIGS. 2A to 2C. This shearing force 152.3 kgf is smaller than the maximum frictional force value Fmax = 225 kgf. Accordingly, even when an impact load corresponding to the impact acceleration 100G is applied, the storage cell 20 does not shift.

FIG. 5 shows the result of calculating the shear force of an actual overlap beam using a framework analysis program. The horizontal axis represents the position in the length direction of the beam, and the vertical axis represents the shear force. Solid lines Fs ₁ and Fs ₂ indicate the shearing force generated on the beam 33 A by the tie rod 33 and the shearing force generated on the beam 30 A by the laminate 30, respectively.

It can be seen that the shear force Fs applied to the entire beam is dispersed into the shear force Fs ₁ applied to the tie rod 33 and the shear force Fs ₂ applied to the laminate 30. Thus, the shear force applied to the laminated body 30 can be reduced by adopting the configuration of the power storage module according to the embodiment. Thereby, impact resistance can be improved.

  When an electric double layer capacitor is used for the storage cell 20, a plurality of electrodes and separators are alternately stacked in the storage cell 20. When the shearing force applied to the stacked body 30 is reduced, the shearing force applied to each of the storage cells 20 is also reduced. Therefore, deviation between the electrode and the separator can be suppressed.

  6A to 6C show various examples of cross-sectional views of the through hole 26 of the heat radiating plate 25 and the tie rod 33 passing therethrough.

  In the example shown in FIG. 6A, a minute gap is provided between the inner peripheral surface of the through hole 26 and the outer peripheral surface of the tie rod 33. In this case, the heat dissipation plate 25 can be displaced until it contacts the tie rod 33. After the contact, the position of the heat sink 25 is restrained by the tie rod.

  In the prototype power storage module, when an impact load corresponding to an impact acceleration of 100G was applied, the deflection amount of the tie rod 33 was about 1.5 mm. If the gap between the inner peripheral surface of the through hole 26 and the outer peripheral surface of the tie rod 33 is about 0.1 mm or less, the tie rod 33 exerts a shearing force after the inner peripheral surface of the opening 26 contacts the tie rod 33 during impact. Functions as a beam to reduce.

  In the example shown in FIG. 6B, the heat radiating plate 25 and the tie rod 33 are fixed to each other by the hot melt adhesive 40. In this case, the position of the heat sink 20 with respect to the tie rod 33 is constrained with respect to the stacking direction of the heat sink 25 and the direction orthogonal thereto.

  In the example shown in FIG. 6C, the through hole 26 of the heat sink 25 is burring processed. When the burring process is performed, the tie rod 33 is easily pressed into the opening 26. In this case, the position of the heat sink 25 relative to the tie rod 33 is constrained with respect to the direction orthogonal to the stacking direction of the storage cells 20. Regarding the stacking direction of the storage cells 20, the movement of the heat sink 20 is allowed with respect to the tie rod 33.

  As shown in FIG. 6D, a slit 27 in the radial direction of the opening 26 may be provided around the opening 26. The diameter of the opening 26 is slightly smaller than the diameter of the tie rod 33. When the tie rod 33 contacts the inner periphery of the opening 26, the position of the heat sink 25 is restrained. Moreover, you may combine a burring process and a slit process.

  FIG. 7 is a schematic cross-sectional view of a power storage device in which a plurality of power storage modules are mounted. A plurality of power storage modules illustrated in FIGS. 1A to 1C are housed in a housing 50. The housing 50 includes a bottom plate 51 and a top plate 52. The top plate 52 is fixed to the bottom plate 51. One holding plate 31 of the power storage module is fixed to the bottom plate 51 with a bolt or the like. A connecting member 42 is fixed to the outer surface of the other pressing plate 31. The connecting member 42 is provided with at least two protrusions 43 protruding in the stacking direction of the storage cells 20.

  On the inner surface of the top plate 52, a recess 53 that matches the projection 43 is provided. By inserting the protrusions 43 into the recesses 53, the relative positions of the pair of pressing plates 31 can be constrained with respect to the rotation direction about the axis parallel to the stacking direction of the power storage modules. Thereby, the twist of an electrical storage module can be prevented. Thus, the protrusion 43 and the recessed part 53 function as a restraining mechanism that suppresses twisting.

  A gap is secured between the connecting member 42 and the top plate 52. For this reason, the displacement of the other pressing plate 31 with respect to one pressing plate 31 is allowed in the direction in which the interval between the pressing plates 31 varies. For this reason, displacement of the pressing plate 31 due to thermal expansion of the storage cell 20 is allowed. Moreover, the dispersion | variation in the space | interval of the press board 31 by the individual difference of an electrical storage module can be absorbed.

  FIG. 8 shows another example of a restraining mechanism that prevents twisting of the power storage module. One pressing plate 31 of the power storage module shown in FIGS. 1A to 1C is fixed to the base 60 with a bolt or the like. A support plate 61 extending in the stacking direction of the storage cells 20 is fixed to the pedestal 60. A groove 32 having a depth direction in a direction parallel to the stacking direction is formed in the other pressing plate 31. A torsion stop 62 having an L-shaped cross section attached to the support plate 61 is inserted into the groove 32. The twisting stop 62 and the groove 32 function as a restraining mechanism that suppresses displacement in the twisting direction.

  This restraining mechanism allows displacement of the presser plate 31 in the direction in which the distance between the pair of presser plates 31 changes.

  FIG. 9A shows another example of a restraining mechanism that prevents twisting of the power storage module. In the example of FIG. 9A, a restraint mechanism having another configuration is used instead of the restraint mechanism including the connecting member 42 and the recess 53 shown in FIG. 7. Other configurations are the same as those of the power storage device of the example shown in FIG.

  FIG. 9B shows a perspective view of the restraining mechanism. The restraining mechanism includes a leaf spring 63 attached to the holding plate 31 and a leaf spring 64 attached to the top plate 52. The two leaf springs 63 and 64 are arranged so as to cross each other at substantially the center thereof. At the intersection, they are fixed to each other by screwing or welding.

  The leaf spring 63 is attached to the holding plate 31 at both ends thereof. The other leaf spring 64 is attached to the top plate 52 at both ends thereof. The two plate springs 63 and 64 prevent the holding plate 31 from being twisted. Further, the pressing plate 31 is allowed to be displaced in the stacking direction by elastically deforming the leaf springs 63 and 64.

  In the configuration shown in FIGS. 7 and 8, a slight twist is generated due to mechanical backlash, a clearance between two members, and the like. On the other hand, in the configuration shown in FIGS. 9A and 9B, no mechanical backlash occurs, and there is no portion where the two members are arranged via a clearance. Therefore, twist can be prevented more effectively.

  In the said Example, although the electrical storage cell 20 and the heat sink 25 showed the structure piled up alternately, it does not necessarily need to be alternate. If the heat sink 25 is disposed at least at one location between the storage cells 20, the effect of reducing the shearing force can be obtained. For example, the heat radiating plate 25 may be arranged every two storage cells 20. The arrangement of the heat sink 25 can be determined based on the impact resistance required for the power storage module.

  Moreover, in the said Example, although the four tie rods 33 are arrange | positioned, from a viewpoint of reducing a shear force, what is necessary is just to arrange | position at least 1 tie rod. In order to connect the pair of pressing plates 31 and apply a compressive force to the laminate 30, it is preferable to arrange at least three tie rods. When three tie rods are arranged, only one tie rod 33 may pass through the through hole 26 of the heat sink 25.

  FIG. 10 is a schematic cross-sectional view of a hybrid work machine equipped with the power storage module according to the embodiment.

  A traveling device 71 is attached to the revolving body 70 via a revolving bearing 73. A revolving body 70, an engine 74, a hydraulic pump 75, an electric motor 76, an oil tank 77, a cooling fan 78, a seat 79, and a power storage module 80. And a motor generator 83 are mounted. The engine 74 generates power by burning fuel. The engine 74, the hydraulic pump 75, and the motor generator 83 transmit and receive torque to and from each other via the torque transmission mechanism 81. The hydraulic pump 75 supplies pressure oil to a hydraulic cylinder such as the boom 82.

  The motor generator 83 is driven by the power of the engine 74 to generate power (power generation operation). The generated power is supplied to the power storage module 80, and the power storage module 80 is charged. In addition, the motor generator 83 is driven by the electric power from the power storage module 80 and generates power for assisting the engine 74 (assist operation). The oil tank 77 stores oil of the hydraulic circuit. The cooling fan 78 suppresses an increase in the oil temperature of the hydraulic circuit. The operator sits on the seat 79 and operates the hybrid work machine.

  As the power storage module 80, the power storage module according to the above embodiment is used. The turning motor 76 is driven by the electric power supplied from the power storage module 80. The turning motor 76 turns the turning body 70. Moreover, the turning motor 76 generates regenerative electric power by converting kinetic energy into electric energy. The power storage module 80 is charged by the generated regenerative power.

  Since the power storage module according to the above embodiment is used for the power storage module 80, destruction of the power storage module 80 due to vibration or impact is suppressed.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

20 Storage cell 20A Beam 21 by storage cell Electrode terminal 25 Heat sink 25A Truss 26 by heat sink 26 Through hole 27 Slit 30 Laminate 31 Press plate 32 Groove 33 Tie rod 33A Beam by tie rod 40 Hot melt adhesive 42 Connecting member 43 Projection 50 Housing Body 51 Bottom plate 52 Top plate 53 Recess 60 Pedestal 61 Support plate 62 Torsion stop 63, 64 Leaf spring 70 Swing body 71 Traveling device 73 Swing bearing 75 Hydraulic pump 76 Swing motor 77 Oil tank 78 Cooling fan 79 Seat 80 Power storage module 81 Torque transmission Mechanism 82 Boom 83 Motor generator

Claims (5)

A plurality of power storage cells having a plate-like shape in which a power storage element is wrapped with a film and stacked in the thickness direction; and at least one heat dissipation plate inserted between the power storage cells, the thickness of the power storage cell When viewed from a line of sight parallel to the vertical direction, an edge of the heat sink extends beyond the edge of the storage cell, and at least one through hole is formed in the extended area of the heat sink Body,
A pair of pressing plates disposed at both ends of the laminate;
A plurality of tie rods that connect the pair of pressing plates and apply a compressive force in the stacking direction to the stacked body;
At least one tie rod is a power storage module passing through the through hole of the heat sink.   The power storage module according to claim 1, wherein the power storage cells and the heat radiating plates are alternately stacked.   The power storage module according to claim 1, wherein a relative position between the tie rod and the heat radiating plate is constrained with respect to a direction orthogonal to the stacking direction of the power storage cells.   Furthermore, the relative position of the pair of pressing plates is constrained with respect to the rotation direction about an axis parallel to the stacking direction of the stacked body, and the direction of the interval between the pressing plates varies with respect to one pressing plate. The power storage module according to any one of claims 1 to 3, further comprising a restraining mechanism that allows displacement of the other pressing plate. The power storage module according to any one of claims 1 to 4,
A hybrid work machine that includes a motor that is driven by electric power supplied from the power storage module, generates regenerative power by converting kinetic energy into electric energy, and charges the power storage module.