JP2015158976A - Hybrid type construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid type construction machine comprising a battery temperature controller that can maintain the heat transfer efficiency between a power storage device and a heat exchange member with stability, independently of change in environmental temperature.SOLUTION: A power storage device 8 is configured to have a plurality of battery cells 30 laminated via an insulation separators 31. Each of the plurality of battery cells 30 has one surface thermally coupled with a water jacket 24 that is a heat exchange member via a heat conduction sheet 36, and is fixed to the heat exchange member 24 by using a fixing member so that a compressive force acts on the heat conduction sheet 36. The fixing member is configured to include an upper stay 34 pressing the battery cell from above.

Description

  The present invention relates to a hybrid construction machine.

  In recent years, even in construction machines such as hydraulic excavators, in order to reduce the fuel consumption, exhaust gas amount and noise by reducing the size of the mounted engine, the power source of the hydraulic pump is hybridized, that is, the engine and electric motor are combined. Is underway. Generally, a construction machine such as a hydraulic excavator is configured to drive a hydraulic pump using a power source and to drive a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder with hydraulic pressure discharged from the hydraulic pump. An engine-type construction machine having only an engine as a power source requires a hydraulic pump that can perform a maximum load work and a large engine that can drive the hydraulic pump.

However, taking an example of a hydraulic excavator, heavy load work such as heavy excavation work that frequently excavates and loads earth and sand is a part of the whole work, and light load work such as horizontal pulling to level the ground. At times, the engine's capacity is surplus. This is one factor that makes it difficult to reduce the amount of fuel consumed by the excavator (hereinafter sometimes referred to as fuel efficiency) and the amount of exhaust gas. In addition, the larger the engine, the greater the noise during heavy load work.

Therefore, a hybrid construction machine has been proposed that solves these problems by reducing the size of the engine and assisting the lack of driving force of the hydraulic pump accompanying the downsizing of the engine with the output of the electric motor. The electric motor receives the supply of electrical energy from the power storage device and drives the hydraulic pump, and converts the regenerative energy of the engine into electrical energy and stores it in the power storage device. These electrical devices such as power storage devices and electric motors require appropriate temperature adjustment because their lifetime and output characteristics vary depending on the temperature.

Conventionally, as a cooling structure of a power storage device mounted on a construction machine or the like, an assembled battery is formed by arranging a plurality of prismatic batteries with an insulating separator in between, and on the cooling surface side of the assembled battery It is known that a cooling plate is provided via a heat conductive sheet having an insulating property (see, for example, claim 1, FIG. 1 and FIG. 2 of Patent Document 1). A compressor, a condenser, and a decompressor are connected to the cooling plate via a refrigerant pipe to constitute a refrigeration cycle. When the refrigerant is circulated in the refrigeration cycle, the cooling plate functions as a heat exchanger for cooling. Therefore, heat exchange is performed between the cooling plate and the assembled battery, and the assembled battery is cooled. According to the description of Patent Document 1, the assembled battery cooling structure having the above configuration abuts the heat conducting sheet on the cooling surface of the assembled battery, and therefore heat exchange between the assembled battery and the cooling plate via the heat conducting sheet. The efficiency can be increased, and the cooling efficiency of the assembled battery can be improved.

As the amount of compression of the heat conductive sheet increases, the thermal resistance decreases, and the heat of the assembled battery can be efficiently transmitted to the cooling plate. The cooling structure of the power storage device described in Patent Document 1 is provided with fastening plates that are fastened toward the center on the left and right side surfaces of the assembled battery toward the center, and provided at both left and right ends of the stationary plate and the cooling plate. The flange is screwed, and the compression force is applied to the heat conductive sheet disposed between the assembled battery and the cooling plate by the tightening force.

JP 2011-34775 A

  However, the cooling structure of the power storage device described in Patent Document 1 is formed by screwing a fixing plate that is in close contact with the left and right side surfaces of the assembled battery and flanges that are provided at both left and right ends of the cooling plate. The compressive force acting on the heat conductive sheet is likely to fluctuate due to changes in temperature, and it is difficult to keep the heat transfer efficiency between the assembled battery and the cooling plate stable. That is, in the rectangular battery constituting the assembled battery, the outer case is formed of aluminum or an aluminum alloy, and the separator disposed between the adjacent rectangular batteries is formed of a resin material. Since the resin material has a larger linear expansion coefficient than aluminum or an aluminum alloy, when the temperature is higher than when the assembled battery is assembled, the thermal expansion amount of the separator becomes larger than the thermal expansion amount of the case of the prismatic battery. For this reason, even if the battery holder for restricting the movement of the rectangular battery in the direction away from the heat conductive sheet is formed in the separator, the movement of the square battery in the direction away from the heat conductive sheet cannot be restricted at high temperatures, In the worst case, the compressive force acting on the heat conductive sheet is lost, and the cooling efficiency of the prismatic battery may be significantly reduced.

Needless to say, construction machines are required to be able to operate in any environment from a low temperature of about −30 ° C. to a high temperature of about + 50 ° C. However, as described above, the cooling structure of the power storage device described in Patent Document 1 is difficult to stably maintain the heat transfer efficiency between the assembled battery and the cooling plate due to a change in environmental temperature. There is room for further improvement in application.

  The present invention has been made in view of the actual situation of the prior art, and an object of the present invention is to provide a battery that can stably maintain the heat transfer efficiency between the power storage device and the heat exchange member regardless of changes in the environmental temperature. The object is to provide a hybrid construction machine equipped with a temperature control device.

  In order to solve the above problems, the present invention employs, for example, the configurations described in the claims. The present invention includes a plurality of means for solving the above-described problems. For example, an engine, an electric motor for assisting power in the engine and recovering energy from the engine, and the electric motor A power storage device that transfers power to and from the battery, and a battery temperature control device that controls the temperature of the power storage device, and the power storage device includes a plurality of battery cells arranged in parallel via an insulating separator. The battery temperature control device includes a heat exchange member that is thermally coupled to one surface of the plurality of battery cells via a heat conductive sheet, and the power storage device and the heat exchange member use a fixing member. And compressing the heat conductive sheet by integrally assembling them, and the fixing member is disposed on the surface of the plurality of battery cells opposite to the surface in contact with the heat conductive sheet; A connecting stay for connecting the tip of the connecting stay to the heat exchanging member, and fixing the tip of the connecting stay to the heat exchanging member directly or indirectly through another member, It comprises an upper stay and a fixture for applying a compressive force to the heat conductive sheet through the plurality of battery cells.

  As described above, the structure in which the power storage device and the heat exchange member are integrally assembled using the fixing member includes an upper stay disposed on the surface (upper surface) opposite to the surface with which the heat conductive sheets of the plurality of battery cells are in contact. If the fixing member is configured, the upper ends of the battery cell and the separator can be pressed by the upper stay, so that the upward movement of the battery cell and the separator can be prevented or suppressed even when the environmental temperature changes. Therefore, the heat conductive sheet can always be kept in a compressed state regardless of the change in the environmental temperature, and the heat transfer efficiency between the battery cell and the heat exchange member can be maintained in a good state.

  According to the present invention, in the hybrid construction machine having the above-described configuration, the upper stay includes a reinforcing rib on a side in a length direction.

  When the reinforcing rib is formed on the side of the upper stay in the length direction, the rigidity of the upper stay can be significantly increased as compared with the case where the rib is not provided. Therefore, since the deformation of the upper stay against the compression reaction force from the heat conductive sheet can be suppressed, the plurality of battery cells and separators provided in the power storage device can be pressed uniformly, and non-uniform lifting of these battery cells and separators can be prevented. it can.

  In the hybrid construction machine having the above-described configuration, a bolt is used as the fixture, and the tip of the connecting stay is directly fastened to one surface of the heat exchange member using the bolt, and the bolt at this time A compression force is applied to the heat conductive sheet by a fastening force of.

  According to such a configuration, a required compressive force can be applied to the heat conductive sheet by appropriately adjusting the clearance between the lower surface of the connecting stay and the upper surface of the heat exchange member before bolt fastening.

  In the hybrid construction machine having the above-described configuration, the fixed shaft is used as the fixture, the fixed shaft is fixed to one surface of the heat exchange member, and one end of the fixed shaft and the tip of the connecting stay An urging member is disposed between the urging member and the urging force of the urging member to constantly apply a compressive force to the heat conductive sheet.

  According to such a configuration, since the compressing force is constantly applied to the heat conducting sheet by the biasing member disposed between one end of the fixed shaft and the tip of the connecting stay, each component constituting the power storage device due to a change in environmental temperature, and Even when thermal expansion or thermal contraction occurs in each member constituting the fixing member, the battery cell can always be pressed against the heat exchange member, and a decrease in heat transfer efficiency due to a change in environmental temperature does not occur.

  In the hybrid construction machine having the above-described configuration, the biasing member includes one or both of a spring, the battery cell, and a spacer having a thermal expansion coefficient larger than that of the fixed shaft. .

  A general-purpose spring member such as a coil spring or a leaf spring can be used as the spring. In addition, as the spacer, a cylindrical resin molded body or the like can be used. Therefore, according to such a configuration, the temperature control structure of the power storage device and thus the hybrid construction machine can be implemented at low cost.

  In the hybrid construction machine having the above-described configuration, the fixed shaft is used as the fixture, the fixed shaft is fixed to one surface of the heat exchange member, and one end of the fixed shaft and the tip of the connecting stay The linear actuator is disposed between the two and the linear actuator is extended at a high temperature to increase the compression amount of the heat conductive sheet, and at the low temperature, the linear actuator is contracted to reduce the compression amount of the heat conductive sheet. It is characterized by.

  According to such a configuration, the linear actuator is arranged between one end of the fixed shaft and the tip of the connecting stay, and the linear actuator is driven to adjust the amount of compression of the heat conductive sheet. Regardless, the amount of compression of the heat conductive sheet can always be maintained stably.

  In the hybrid construction machine having the above-described configuration, the upper stay and the plurality of battery cells are formed of a material having a larger thermal expansion coefficient than the upper stay, the connection stay, and the battery cell. Two wedge-shaped spacers in which slopes are combined to face each other are arranged.

  According to such a configuration, at a high temperature, the two wedge-shaped spacers are thermally expanded to cause slippage between the slopes of the respective wedge-shaped spacers, and the total thickness of the two wedge-shaped spacers is increased. On the other hand, at a low temperature, the two wedge-shaped spacers are thermally contracted to cause slippage between the slopes of the respective wedge-shaped spacers, and the total thickness of the two wedge-shaped spacers is reduced. Therefore, the amount of compression of the heat conductive sheet can always be stably maintained regardless of changes in the environmental temperature.

  According to the present invention, it is possible to stably maintain the heat transfer efficiency between the power storage device and the heat exchange member regardless of changes in the environmental temperature, and to improve the reliability and operating efficiency of the hybrid construction machine. it can. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a side view of a hybrid hydraulic excavator according to an embodiment. 1 is a system configuration diagram of an electric system and a hydraulic system included in a hybrid hydraulic excavator according to an embodiment. FIG. 1 is a system configuration diagram of a battery temperature control device provided in a hybrid excavator according to an embodiment. FIG. 1 is a perspective view of a power storage device and a water jacket according to Embodiment 1. FIG. It is a longitudinal cross-sectional view of FIG. It is a perspective view of the electrical storage apparatus and water jacket which concern on Example 1 which removed the upper stay. It is sectional drawing of the electrical storage apparatus which concerns on Example 2, and a water jacket. It is sectional drawing of the electrical storage apparatus which concerns on Example 3, and a water jacket. It is a graph which shows the temperature of the electrical storage apparatus which concerns on Example 3, and the relationship between the heat conductive sheet compression amount. It is sectional drawing of the electrical storage apparatus which concerns on Example 4, and a water jacket. It is sectional drawing of the electrical storage apparatus which concerns on Example 5, and a water jacket.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking a hybrid hydraulic excavator as an example.

  First, the overall configuration of the hybrid excavator according to the embodiment will be described with reference to FIGS. 1 is a side view of a hybrid hydraulic excavator according to the embodiment, FIG. 2 is a system configuration diagram of an electric system and a hydraulic system included in the hybrid hydraulic excavator according to the embodiment, and FIG. 3 is a hybrid type according to the embodiment. It is a system block diagram of the battery temperature control apparatus with which a construction machine is provided.

  As shown in FIG. 1, the hybrid hydraulic excavator according to the embodiment includes a traveling body 100 provided with a crawler 101 and a driving wheel 102 of the crawler 101, a revolving body 110 provided on the traveling body 100 so as to be capable of turning, A front device 70 having one end rotatably connected to the revolving unit 110 is provided. The drive wheel 102 and the turning body 110 are turned using a hydraulic motor (not shown). In the example of FIG. 1, the traveling body 100 includes the crawler 101, but the traveling body 100 may include a wheel instead of the crawler 101.

  The swivel body 110 has a swivel frame 111, a cab 3 provided at the front portion of the swivel frame 111, and a prime mover chamber 112 provided at the rear portion of the swivel frame 111. In the prime mover chamber 112, the engine 1, the electric motor 2 that assists in insufficient output of the engine 1, the hydraulic pump 5 that is driven by the engine 1 or by both the engine 1 and the electric motor 2, and the discharge from the hydraulic pump 5 A hydraulic system 90 such as a valve device that distributes the pressurized oil to a required hydraulic actuator (generic name for a hydraulic motor and a hydraulic cylinder) is mounted. The cab 3 includes an operating device 4 for operating the hydraulic actuator, and a controller 11 that outputs control signals for the engine 1 and the electric motor 2 in accordance with the operation amount and operating direction of the operating device 4. The hydraulic system will be described later with reference to FIG.

  The front device 70 includes a boom 71 having one end rotatably connected to the swing body 110, a boom hydraulic cylinder 72 for driving the boom 71, and an arm 73 rotatably connected to the tip of the boom 71. The arm hydraulic cylinder 74 for driving the arm 73, the bucket 75 rotatably connected to the tip of the arm 73, the bucket hydraulic cylinder 76 for driving the bucket 75, and the like. Instead of the bucket 75, other attachments such as a breaker, a crusher, a cutter, a grapple, or a lifting magnet can be attached.

As shown in FIG. 2, the electric system and hydraulic system of the hybrid excavator include an engine 1 and an electric motor 2 for driving a hydraulic pump 5 and a pilot hydraulic pump 6. The engine 1 includes a governor 7 that adjusts the fuel injection amount of the engine 1, a rotation speed sensor 1 a that detects the actual rotation speed of the engine 1, and an engine torque sensor 1 b that detects the output torque of the engine 1. The governor 7 controls the fuel injection amount based on the control signal output from the controller 11 so that the actual rotation speed and the actual torque of the engine 1 become the target rotation speed and the target torque indicated by the operation device 4. The exhaust passage 84 of the engine 1 is provided with an exhaust gas purification system including a selective catalytic reduction catalyst (SCR catalyst) 80, a reducing agent adding device 81, and a urea tank 82 storing urea. The exhaust gas of the engine 1 is purified by the selective catalytic reduction catalyst (SCR catalyst) 80 and the nitrogen oxides in the exhaust gas are purified and released to the atmosphere via the silencer 83.

The electric motor 2 is driven by receiving electric energy supplied from the power storage device 8 and assists in the shortage of the output of the engine 1, and also converts the regenerative energy recovered from the engine 1 into electric energy and stores it in the power storage device 8. To do. As the power storage device 8, a battery or a capacitor can be used. A current sensor, a voltage sensor, and a temperature sensor (not shown) are attached to the power storage device 8, and the controller 11 determines the power storage device 8 based on information such as current, voltage, and temperature detected by these sensors. The power storage amount is calculated and the power storage amount of the power storage device 8 is managed. Transmission and reception of electric power between the electric motor 2 and the power storage device 8 is performed via the inverter device 9. The inverter device 9 controls the voltage value and frequency of power supplied to the electric motor 2 based on the control signal output from the controller 11. The power storage device 8 is provided with a battery temperature adjustment device 20 shown in FIG. 3, and is maintained at an appropriate temperature by the battery temperature adjustment device 20. The configuration of the battery temperature control device 20 will be described later with reference to FIG.

As the hydraulic pump 5, a swash plate pump that has a swash plate in the variable displacement mechanism and controls the discharge flow rate of the pressure oil by adjusting the tilt angle of the swash plate is preferably used. Hereinafter, a case where a swash plate pump is used as the hydraulic pump 5 will be described as an example. The hydraulic pump 5 includes a pump capacity adjusting device 10 for adjusting the capacity of the hydraulic pump 5. The pump capacity adjusting device 10 adjusts the capacity (displacement volume) of the hydraulic pump 5 based on a control signal output from the controller 11, and includes a regulator 13 and an electromagnetic proportional valve 14. The regulator 13 operates the tilt angle of the swash plate of the hydraulic pump 5 to control the absorption torque (input torque) of the hydraulic pump 5. The electromagnetic proportional valve 14 is controlled by a command value from the controller 11 and controls the operation amount of the regulator 13. The pressure oil discharged from the hydraulic pump 5 is supplied to the hydraulic actuator (72, 74, 76, etc.) via the valve device 12. Although not shown, the hydraulic system includes a discharge pressure sensor that detects the pressure of the pressure oil discharged from the hydraulic pump 5, a flow meter that detects the flow rate of the pressure oil discharged from the hydraulic pump 5, and A tilt angle sensor for detecting the tilt angle of the swash plate of the hydraulic pump 5 is provided.

The pilot hydraulic pump 6 is a small hydraulic pump that supplies pressure oil for generating a hydraulic signal (pilot pressure) by the operation device 4. The operating device 4 is provided in a pipeline P that connects the pilot hydraulic pump 6 and the pilot port of the valve device 12. The operation device 4 applies a pilot pressure corresponding to the operation amount and operation direction to the pilot port of the valve device 12.

  The controller 11 takes in the discharge pressure of the hydraulic pump 5 detected by the discharge pressure sensor, the discharge flow rate of the hydraulic pump detected by the flow meter, and the tilt angle of the swash plate detected by the tilt angle sensor. The load of the pump 5 is calculated. Further, the controller 11 takes in the pilot pressure corresponding to the operation amount and the operation direction from the operation device 4. Then, the controller 11 calculates a command value to be given to the electromagnetic proportional valve 14 from the load of the hydraulic pump 5 obtained by the calculation and the pilot pressure taken in from the operating device 4, and the calculated command value signal is used as the electromagnetic proportional valve. 14 for output. At this time, the controller 11 takes into account the actual rotational speed of the engine 1 detected by the rotational speed sensor 1a and the output torque of the engine 1 detected by the engine torque sensor 1b, so that no engine stall occurs. Adjust the tilt angle.

  Therefore, in the hybrid hydraulic excavator according to the embodiment, when the operator who has boarded the cab 3 operates the operation device 4, the pilot pressure corresponding to the operation amount and operation direction of the operation device 4 is changed to the required pilot of the valve device 12. Acting on the port, the spool position of the control valve connected to the pilot port is switched. As a result, the pressure oil discharged from the hydraulic pump 5 is selectively supplied to the required hydraulic actuators 72, 74, and 76 at the flow rate, direction, and pressure instructed by the operation device 4, and the required work is performed. The valve device 12 is not limited to the hydraulic pilot type, and an electromagnetic pilot type valve device can also be used.

  In FIG. 3, the structure of the battery temperature control apparatus 20 is shown. In the hybrid hydraulic excavator, the assisting electric motor 2 and the inverter device 9 are also provided with a cooling circuit, but these are matters that are well-known and are not the gist of the present invention. Is omitted.

  As shown in FIG. 3, the battery temperature control device 20 according to the embodiment warms up the power storage device 8 and a cooling circuit 21 that circulates a device temperature control medium such as cooling water to cool the power storage device 8. Therefore, a warm-up circuit 22 that circulates the device temperature control medium is provided. Therefore, the battery temperature control device 20 according to the embodiment can prevent overheating of the power storage device 8 and also prevent overcooling of the power storage device 8 to reduce charge and discharge efficiency at the start of the winter when the outside temperature is low. Can be prevented. Since the main object of the present invention is to prevent the cooling efficiency of the power storage device 8 from being lowered when the outside air temperature is high, a battery temperature control device having only the cooling circuit 21 can be applied.

  The cooling circuit 21 uses liquid piping for a circulation pump 23 for the device temperature control medium, a water jacket 24 that is a heat exchange member with the power storage device 8, and a radiator 26 that radiates the heat of the device temperature control medium to the outside. And connected in a ring. By the way, since the construction machine is used at a site with a lot of dust, the air-cooled battery temperature control device is not preferable in terms of protecting the power storage device 8. When the water-cooled battery temperature control device 20 according to the embodiment is used, it is not necessary to blow cooling air containing dust onto the power storage device 8, so that the power storage device 8 can be prevented from being damaged by dust.

  The liquid piping on the outlet side of the water jacket 24 is provided with a temperature sensor such as a thermistor or a thermocouple to detect the temperature of the device temperature control medium. The temperature signal of the device temperature control medium detected by the temperature sensor is output to the controller 11 (see FIG. 2).

  The warm-up circuit 22 includes a circulation pump 23 for the device temperature control medium, a water jacket 24 that is a heat exchange member with the power storage device 8, and a heater 28 for heating the device temperature control medium in an annular shape using liquid piping. Connected. The heater 28 is arranged in parallel with the radiator 26, and one end side thereof is connected to the liquid pipe on the outlet side of the water jacket 24 of the cooling circuit 21, and the other end side is connected to the liquid pipe on the inlet side of the pump 23. As the heater 28, any known heater can be used. However, since the power consumption is small and the temperature stability is excellent, a heater composed of a PTC (Positive Temperature Coefficient) element or the like is used. Is preferred.

  The cooling circuit 21 is provided with a first two-way valve 29A, and the warm-up circuit 22 is provided with a second two-way valve 29B. Therefore, when the first two-way valve 29A is opened and the second two-way valve 29B is closed and the pump 23 is driven, the device temperature control medium radiated by the radiator 26 flows to the water jacket 24, and the power storage device 8 Can be cooled. When the first two-way valve 29A is closed and the second two-way valve 29B is opened and the pump 23 is driven, the device temperature control medium heated by the heater 28 flows into the water jacket 24, and the power storage device 8 Can warm up. The controller 11 can automatically switch the opening and closing of the first two-way valve 29 </ b> A and the second two-way valve 29 </ b> B and the on / off switching of the pump 23 and the heater 28 based on the temperature of the power storage device 8. .

  In order to control the temperature of the power storage device 8 during cooling, either the flow rate of the pump 23 or the air volume of the fan 27 may be adjusted. Specifically, when the power storage device 8 is higher than the target temperature, either the flow rate of the pump 23 or the air volume of the fan 27 may be increased. Further, when the power storage device 8 is lower than the target temperature, either the flow rate of the pump 23 or the air volume of the fan 27 may be reduced.

  Further, in order to control the temperature of the power storage device 8 during warm-up, either the flow rate of the pump 23 or the heat generation amount of the heater 28 may be adjusted. Specifically, when the power storage device 8 is lower than the target temperature, either the flow rate of the pump 23 or the heat generation amount of the heater 28 may be increased. Further, when the power storage device 8 is higher than the target temperature, either the flow rate of the pump 23 or the heat generation amount of the heater 28 may be reduced.

  Note that, when the temperature of the power storage device 8 is low and the warm-up operation is necessary, the power storage device 8 can be warmed up by charging / discharging and generating heat by the internal resistance of the power storage device 8. In the present embodiment, the warm-up circuit 22 including the heater 28 is provided as shown in FIG. 3, but the warm-up operation may be performed only by charging / discharging the power storage device 8 without installing the warm-up circuit 22. good.

  Next, the cooling structure of the power storage device 8 mounted on the hybrid hydraulic excavator will be described for each embodiment.

[Example 1]
The temperature control structure of the power storage device 8 according to the first embodiment is characterized in that the power storage device 8 is rigidly fixed to the water jacket 24 as shown in FIGS. 4 is a perspective view of the power storage device 8 and the water jacket 24 according to the first embodiment, FIG. 5 is a longitudinal sectional view of FIG. 4, and FIG. 6 is a diagram of the power storage device 8 and the water jacket 24 according to the first embodiment with the upper stay removed. It is a perspective view.

As shown in FIGS. 4 to 6, the temperature control structure of the power storage device 8 according to the first embodiment includes a plurality of battery cells 30 stacked in the thickness direction, and separators 31 respectively disposed on the front and back surfaces of each battery cell 30. And two end plates 32 that are disposed at both ends of the battery cells 30 to be stacked and support the outer surface of the battery cell 30; a connecting member 33 that connects and fixes the two end plates 32; The upper stay 34 that holds the upper part and restricts the upward movement of the battery cell 30 and the connection stay 35 that fixes the battery cell 30 to the water jacket 24 are mainly configured. The connecting member 33 is fastened to the end plate 32 using bolts 37. The upper stay 34 is fastened to the fixing member 35 and the end plate 32 using bolts 38. Further, the connecting stay 35 is fastened to the water jacket 24 using bolts 39.

As shown in FIG. 5, a heat conductive sheet 36 is installed between the lower surface (cooling surface) of each battery cell 30 constituting the power storage device 8 and the water jacket 24. Thereby, the lower surface of the battery cell 30 and the water jacket 24 are thermally coupled.

The battery cell 30 is a lithium ion secondary battery, and the exterior case formed of aluminum or an aluminum alloy has a rectangular box shape. However, the battery cell 30 may be another battery such as a nickel metal hydride battery or a nickel cadmium battery. Positive and negative electrode terminals 30A project from both end portions of the upper surface of the battery cell 30, and adjacent positive and negative electrode terminals 30A are connected in series by being connected by a bus bar (not shown). The power storage device 8 that connects adjacent battery cells 30 in series can increase the output voltage and increase the output. However, the power storage device 8 can also connect adjacent battery cells 30 in parallel.

The separator 31 insulates between two battery cells 30 arranged adjacent to each other, and is formed of an insulating material such as resin. As shown in FIG. 5, a battery holding portion 31 </ b> A is formed at the upper end portion of the separator 31 in order to prevent vertical displacement of the two battery cells 30 disposed via the separator 31.

The end plate 32 has substantially the same appearance as the battery cell 30 and has a spring structure (not shown) on its inner surface so that a pressing force can be applied to the stacked battery cells 30 and the separator 31. ing. That is, by connecting the two end plates 32 that are in contact with the battery cells 30 at both ends by the connecting member 33, a pressing force is applied to the plurality of battery cells 30 and the separators 31 that are stacked on each other, and each battery cell. 30 and the position shift of each separator 31 are regulated. As shown in FIG. 4, the connecting member 33 has a shape in which both ends are bent in the same direction, and the bent both ends are fastened to the end plate 32 with bolts 37. The end plate 32 and the connecting member 33 function as an assembly member for assembling the battery cells 30 integrally.

The water jacket 24 is a member for controlling the temperature of the power storage device 8 and is attached in a state where it is thermally coupled to the lower surface of the battery cell 30 (surface opposite to the electrode terminal 30A). The water jacket 24 is formed in a thin plate shape with a metal material such as aluminum, and has an apparatus temperature adjusting medium inlet 24A and an apparatus temperature adjusting medium outlet 24B on its end surface as shown in FIG. The equipment temperature adjusting medium inlet 24A is connected to the outlet of the pump 23, and the equipment temperature adjusting medium 24B is connected to the inlet of the radiator 26 and the inlet of the heater 28. A groove (not shown) through which the device temperature adjusting medium circulates is formed inside the water jacket 24, so that heat exchange is efficiently performed between the battery cell 30 and the device temperature adjusting medium. When cooling the battery cell 30, as described above, the device temperature control medium heated by the battery cell 30 is cooled by circulating the device temperature control medium to the radiator 26. Further, when the battery cell 30 is warmed up, the battery cell 30 is warmed up by circulating the device temperature control medium warmed by the heater 28.

As described above, both the water jacket 24 and the outer case of the battery cell 30 are made of a metal material, and the power storage device 8 connecting the adjacent battery cells 30 in series has a potential difference between the adjacent battery cells 30. There is. Accordingly, when the battery cell 30 is directly installed on the water jacket 24, a large short current flows. In order to prevent this, an insulating heat conductive sheet 36 is installed between the battery cell 30 and the water jacket 24. Moreover, in order to maintain the thermal coupling between the water jacket 24 and the battery cell 30 even when the heat conductive sheet 36 has some unevenness on the surface of the water jacket 24 and the lower surface of the battery cell 30, An elastic body is desirable. Examples of this type of heat conductive sheet 36 include a silicon resin sheet, a plastic sheet filled with a filler having excellent heat conductivity, mica, and the like, but other materials may be used as long as the same effect can be obtained. Absent.

As shown in FIG. 5, the upper stay 34 is a member for holding the upper surface of the battery holding portion 31 </ b> A formed at the upper end portion of the separator 31 and restricting the upward movement of the battery cell 30. A connecting piece 34 a that is bent in the side surface direction of the power storage device 8 is formed at both ends. As shown in FIG. 4, reinforcing ribs 34b are formed on the intermediate portion of the upper stay 34 excluding the connecting piece 34a, that is, on the side of the portion of the separator 31 that contacts the battery holding portion 31A. Increases rigidity against stress. Thereby, the some separator 31 and the battery cell 30 can be pressed uniformly.

The connecting stay 35 is a member for fixing the power storage device 8 to the water jacket 24 via the upper stay 34, and is formed by bending a metal plate into an L shape as shown in FIGS. As shown in FIG. 5, the main portion 35a of the connecting stay 35 contacts the outer surface of the end plate 32, and is fixed to the end plate 32 using bolts 38 inserted from the outside of the connecting piece 34a. The fixing portion 35b of the connecting stay 35 is fixed to the water jacket 24 using a bolt 39 inserted from above the fixing portion 35b. Thereby, the movement of the battery cell 30 with respect to the water jacket 24 in the front-rear, left-right, and vertical directions is restricted. When the fixing portion 35b is fixed to the water jacket 24, a clearance is provided between the lower surface of the fixing portion 35b and the upper surface of the water jacket 24, and the power storage device 8 and the water jacket are tightened by the tightening force of the bolt 39. A compressive force is applied to the heat conducting sheet 36 provided between the heat conducting sheet 24 and the heat conducting sheet 36. As a result, the upper stay 34 is uniformly pressed against the upper surface of the power storage device 8, and all the battery cells 30 constituting the power storage device 8 are uniformly pressed against the water jacket 24 via the heat conductive sheet 36. High-efficiency heat exchange is performed between 30 and the water jacket 24.

In the temperature control structure of the power storage device 8 according to the first embodiment, the highly rigid upper stay 34 is pressed against the upper portion of the power storage device 8, and compressive force is applied to the heat conductive sheet 36 by the power storage device 8 and the water jacket 24. The heat conductive sheet 36 made of an elastic material is elastically deformed. For this reason, the power storage device 8, the heat conductive sheet 36, and the water jacket 24 are kept in close contact with each other regardless of changes in the environmental temperature, and highly efficient heat exchange between the battery cell 30 and the water jacket 24 is possible. Become.

That is, as shown in FIG. 6, when the upper stay 34 is not provided, when the environmental temperature changes, the upward movement of the battery cell 30 and the separator 31 is regulated by the end plate 31 and the connecting member. There is only frictional force due to 33 clamping force. As described above, the outer case of the battery cell 30 is made of a metal material such as aluminum, and the separator 31 is formed using an insulating resin having a linear expansion coefficient larger than that of the metal material such as aluminum. When the environmental temperature becomes higher than that at the time of assembly of 8, the battery cell 30 can move in the direction away from the heat conductive sheet 36 by the difference between the extension amount of the separator 31 and the extension amount of the battery cell 30. For this reason, even if a compressive force is applied to the heat conductive sheet 36 in advance, the amount of compression of the heat conductive sheet 36 is reduced due to a change in the environmental temperature, and the heat transfer efficiency may be reduced. In the configuration shown in FIG. 6, in order to suppress the upward movement of the battery cell 30 at a high temperature, the clamping force of the battery cell 30 by the end plate 31 and the connecting member 33 must be increased. It is not preferable for protection of the battery cell 30.

On the other hand, if the metal upper stay 34 is pressed against the upper portion of the power storage device 8, the upward movement of the battery cell 30 can be regulated regardless of the extension of the separator 31. The state where the heat conductive sheet 36 is compressed can be maintained. Further, the rib 34b for reinforcement is formed on the side of the upper stay 34, and the rigidity against the compression reaction force from the heat conductive sheet 36 is increased, so that the plurality of separators 31 and the battery cells 30 can be pressed uniformly, and the separator The uneven lifting of 31 and the battery cell 30 can also be prevented.

[Example 2]
Next, the temperature control structure of the power storage device 8 according to the second embodiment will be described with reference to FIG. FIG. 7 is a cross-sectional view of the temperature control structure of the power storage device 8 according to the second embodiment. This embodiment is characterized in that a spring 41 is disposed between the connecting stay 35 and the water jacket 24.

  In FIG. 7, reference numeral 40 indicates a fixed shaft, and reference numeral 41 indicates a spring. Since the configuration of other power storage device 8 is the same as that of power storage device 8 according to the first embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted. Fixed shaft 40 is attached to the power storage device mounting surface of water jacket 24. A through hole of the fixed shaft 40 is formed in the fixed portion 35b of the connection stay 35, and the connection stay 35 is fixed to the water jacket 24 by fixing the tip end portion of the fixed shaft 40 inserted into the through hole. It is attached to the jacket 24 so that it can move up and down. The spring 41 is disposed in a compressed state between the fixed portion 35 b of the connecting stay 35 and the head portion 40 a of the fixed shaft 40. Therefore, in the hybrid excavator according to the present embodiment, the upper stay 34 is pressed against the power storage device 8 by the elastic force of the spring 41. In addition, the lower end of the fixed shaft 40 is provided with a stopper 40b, and the amount of compression of the heat conductive sheet 36 is adjusted by changing the height of the stopper 40b. As described above, in the hybrid hydraulic excavator according to the second embodiment, the upper stay 34 and the connecting stay 35 are elastically held by the water jacket 24, so that each component constituting the power storage device and the upper stay are changed by a change in environmental temperature. 34, the connecting stay 35, the fixed shaft 40, and the like can be pressed against the water jacket 24 without always reducing the compression amount of the heat conductive sheet 36 even when the thermal expansion or thermal contraction of the thermal expansion sheet 36 is performed. Does not drop. In FIG. 7, a coil spring is illustrated as an example of the spring 41. However, other springs such as a leaf spring may be used as long as the same effect can be obtained.

Example 3
Next, the temperature control structure of the power storage device 8 according to the third embodiment will be described with reference to FIG. FIG. 8 is a cross-sectional view of the temperature control structure of the power storage device 8 according to the third embodiment. This embodiment is characterized in that a cylindrical elastic spacer 42 is disposed between the connecting stay 35 and the water jacket 24.

In FIG. 8, reference numeral 40 denotes a fixed shaft, and reference numeral 42 denotes a cylindrical spacer. Since the configuration of other power storage device 8 is the same as that of power storage device 8 according to the second embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted. Fixed shaft 40 is attached to the power storage device mounting surface of water jacket 24. A through hole of the fixed shaft 40 is formed in the fixed portion 35b of the connection stay 35, and the connection stay 35 is fixed to the water jacket 24 by fixing the tip end portion of the fixed shaft 40 inserted into the through hole. It is attached to the jacket 24 so that it can move up and down. The cylindrical spacer is formed in a cylindrical shape with a material having a larger linear expansion coefficient than that of the connecting stay 35 and the fixed shaft 40, for example, a resin material, and between the fixed portion 35b of the connecting stay 35 and the head portion 40a of the fixed shaft 40. Arrange without gaps. Therefore, the hybrid excavator according to the present embodiment can press the upper stay 34 against the power storage device 8.

In the hybrid hydraulic excavator according to the present embodiment, the cylindrical spacer 42 is disposed between the fixed portion 35b of the connecting stay 35 and the head 40a of the fixed shaft 40. The amount of compression of the heat conductive sheet 36 can be adjusted by utilizing the characteristic that the shape spacer 42, the connecting stay 35, the battery cell 30, and the separator 31 thermally expand or contract. That is, when a cylindrical spacer 42 made of, for example, a resin material having a large linear expansion coefficient is disposed between the fixed portion 35b of the connecting stay 35 and the head 40a of the fixed shaft 40, the cylindrical spacer 42 is connected to the connecting stay at a high temperature. 35 and the fixed shaft 40, the connection stay 35 moves downward, and the amount of compression of the conductive sheet 36 by the battery cell 30 increases. On the other hand, since the cylindrical spacer 42 is more thermally contracted than the connection stay 35 and the fixed shaft 40 at a low temperature, the connection stay 35 moves upward, and the amount of compression of the heat conductive sheet 36 by the battery cell 30 is reduced. .

As shown in FIG. 9, at a high temperature, it is desirable to increase the amount of compression of the heat conductive sheet 36 in order to increase the heat transfer efficiency from the battery cell 30 to the water jacket 24. On the other hand, at low temperatures, it is desirable to prevent heat generated by charging / discharging of the power storage device 8 from being transferred to the water jacket 24 side. That is, in order to obtain good discharge characteristics at low temperatures, it is desirable to reduce the amount of compression of the heat conductive sheet 36 by reducing the heat transfer efficiency from the battery cell 30 to the water jacket 24. According to the present embodiment, the elastic spacer 42 made of, for example, a resin material having a large linear expansion coefficient is disposed between the fixing portion 35b of the connecting stay 35 and the head portion 40a of the fixing shaft 40. Good charge / discharge characteristics of the device 8 can be obtained.

Example 4
Next, the temperature control structure of the power storage device 8 according to the fourth embodiment will be described with reference to FIG. FIG. 10 is a cross-sectional view of the temperature control structure of the power storage device 8 according to the fourth embodiment. This embodiment is characterized in that a linear actuator 43 such as a piezo element is disposed between the connecting stay 35 and the water jacket 24.

In FIG. 10, reference numeral 40 denotes a fixed shaft, and reference numeral 43 denotes a linear actuator such as a piezoelectric element. Since the configuration of other power storage device 8 is the same as that of power storage device 8 according to the second embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted. Fixed shaft 40 is attached to the power storage device mounting surface of water jacket 24. A through hole of the fixed shaft 40 is formed in the fixed portion 35b of the connection stay 35, and the connection stay 35 is fixed to the water jacket 24 by fixing the tip end portion of the fixed shaft 40 inserted into the through hole. It is attached to the jacket 24 so that it can move up and down. The length of the linear actuator 43 is changed by, for example, a control signal from the controller 11 (see FIG. 2). Therefore, the linear actuator 43 is disposed between the fixed portion 35b of the connecting stay 35 and the head portion 40a of the fixed shaft 40, and the length of the linear actuator 43 is controlled by a control signal from the controller 11, for example. The stay 34 can be pressed against the power storage device 8.

  Similar to the power storage device 8 according to the third embodiment, the power storage device 8 according to the fourth embodiment increases the compression amount of the heat conductive sheet 36 by increasing the length of the linear actuator 43 at a high temperature. The heat transfer efficiency between the cell 30 and the water jacket 24 is increased. On the contrary, when the temperature is low, the length of the linear actuator 43 is shortened, the amount of compression of the heat conductive sheet 36 is reduced, and the heat transfer efficiency between the battery cell 30 and the water jacket 24 is lowered. Thereby, the favorable charging / discharging characteristic of the electrical storage apparatus 8 at the time of low temperature can be maintained.

Example 5
Next, the temperature control structure of the power storage device 8 according to the fifth embodiment will be described with reference to FIG. FIG. 11 is a cross-sectional view of the temperature control structure of the power storage device 8 according to the fifth embodiment. The present embodiment is characterized in that two wedge-shaped spacers 44 and 45 are arranged between the upper stay 34 and the upper end portion 31A of the separator 31.

In FIG. 11, reference numerals 44 and 45 indicate two wedge-shaped spacers in which the slopes are combined to face each other. Since the configuration of other power storage device 8 is the same as that of power storage device 8 according to the first embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 11, the two wedge-shaped spacers 44 and 45 are disposed between the upper stay 34 and the upper end portion 31 </ b> A of the separator 31 in a state where the inclined surfaces are combined to face each other. The first wedge-shaped spacer 44 is formed to be shorter than the width dimension of the upper stay 34, and the end on the thick side abuts against one side of the upper stay 34. On the other hand, the second wedge-shaped spacer 45 is formed shorter than the width dimension of the upper stay 34, and the end portion on the thick side abuts against the other side portion of the upper stay 34. These two wedge-shaped spacers 44 and 45 are formed of a material having a larger linear expansion coefficient than that of the upper stay 34, the connecting stay 35, and the battery cell 30, for example, a resin material. The total thickness when the two wedge-shaped spacers 44 and 45 are combined is the same as that when the two wedge-shaped spacers 44 and 45 are disposed between the upper stay 34 and the upper end portion 31A of the separator 31. It is set as the predetermined dimension which can give compressive force to. Thereby, the hybrid hydraulic excavator according to the present embodiment can press the upper stay 34 against the power storage device 8.

In the temperature control structure of the power storage device 8 according to the fifth embodiment, two wedge-shaped spacers 44 and 45 formed of a material with a large linear expansion coefficient are combined with the upper stay 34 and the upper end portion 31A of the separator 31 with the inclined surfaces facing each other. Since the end portions on the thick side of the wedge-shaped spacers 44 and 45 are abutted against the side portions of the upper stay 34, the thermal expansion and contraction of the wedge spacers 44 and 45 are utilized. The compressive force acting on the heat conductive sheet 36 can be adjusted. That is, at high temperatures, the wedge-shaped spacers 44 and 45 expand in the length direction, so that slip occurs between the slopes of the two wedge-shaped spacers 44 and 45, and the total thickness of the wedge-shaped spacers increases. The amount of compression increases. Thereby, since the heat transfer efficiency between the battery cell 30 and the water jacket 24 becomes high, the battery cell 30 can be cooled efficiently. On the other hand, since the wedge-shaped spacers 44 and 45 contract in the length direction at a low temperature, slippage occurs between the slopes of the two wedge-shaped spacers 44 and 45, thereby reducing the total thickness of the wedge-shaped spacers. The amount of compression of the sheet 36 is reduced. Thereby, since the heat transfer efficiency between the battery cell 30 and the water jacket 24 becomes low, cooling of the battery cell 30 is suppressed and required charge / discharge efficiency is maintained.

In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change arbitrarily and can implement.

For example, in the first to fifth embodiments described above, the upper stay 34 and the connecting stay 35 are formed as separate bodies. However, the gist of the present invention is not limited thereto, and the upper stay 34 and the connecting stay 35 are not limited thereto. Can also be formed integrally.

In the above-described embodiment, the hybrid hydraulic excavator is described as an example, but the present invention can also be applied to an electric construction machine such as an electric hydraulic excavator.

Further, in the first to fifth embodiments described above, one set of power storage devices 8 is installed and fixed on one water jacket 24, but two or more power storage devices may be installed on one water jacket 24. good. Of course, the number of battery cells 30 may be different from that shown in FIG. Furthermore, the power storage device 8 can be made of a combination of capacitors in addition to a combination of battery cells 30.

  Moreover, the techniques described in the first to fifth embodiments described above can be used not only independently but also in combination. When used in combination, the synergistic effects of the respective embodiments can be expected.

DESCRIPTION OF SYMBOLS 1: Engine, 1a: Speed sensor, 1b: Engine torque sensor, 2: Electric motor, 3: Driver's cab, 4: Operating device, 5: Hydraulic pump, 6: Pilot hydraulic pump, 7: Governor, 8: Power storage device , 9: inverter device, 10: pump capacity adjustment device, 11: controller, 12: valve device, 13: regulator, 14: electromagnetic proportional valve, 20: battery temperature control device, 21: cooling circuit, 22: warm-up circuit, 23: Pump, 24: Water jacket (heat exchange member), 25: Compressor, 25a: Clutch, 26: Radiator, 27: Fan, 28: Heater, 29A, 29B: Two-way valve, 30: Battery cell, 30A: Electrode terminal, 31: separator, 31A: upper end of separator, 32: end plate, 33: connecting member, 34: upper stay, 35: connecting stay, 36: heat Guide sheet, 37, 38, 39: bolt, 40: fixed shaft, 41: spring, 42: cylindrical spacer, 43: linear actuator, 44, 45: wedge spacer, 70: shovel mechanism, 71: boom, 72: boom Cylinder, 73: Arm, 74: Arm cylinder, 75: Bucket, 76: Bucket cylinder, 80: Selective catalytic reduction catalyst (SCR catalyst), 81: Reductant addition device, 82: Urea tank, 83: Muffler, 84: Exhaust passage, 90: hydraulic system, 100: traveling body, 110: rotating body, 111: rotating frame, 112: prime mover room

Claims (7)

An engine, an electric motor that assists in powering the engine and recovers energy from the engine, a power storage device that transfers power to and from the electric motor, and a battery temperature control device that controls the temperature of the power storage device With
The power storage device includes a plurality of battery cells arranged in parallel via an insulating separator, and the battery temperature control device is thermally exchanged with one surface of the plurality of battery cells via a heat conductive sheet. Having a member, the power storage device and the heat exchanging member apply a compressive force to the heat conductive sheet by assembling integrally using a fixing member,
The fixing member is disposed on the side of the power storage device, the upper stay disposed on the surface of the plurality of battery cells opposite to the surface on which the heat conductive sheet is in contact, and the tip portion of the fixing member is disposed on the heat exchange member. The connecting stay to be connected and the tip of the connecting stay are directly or indirectly fixed to the heat exchange member via another member, and compressed to the heat conductive sheet via the upper stay and the plurality of battery cells. A hybrid construction machine characterized by comprising a fixture for applying force.   The hybrid construction machine according to claim 1, wherein the upper stay includes a reinforcing rib on a side in a length direction.   A bolt is used as the fixture, and the tip of the connecting stay is directly fastened to one surface of the heat exchange member using the bolt, and a compression force is applied to the heat conductive sheet by the fastening force of the bolt at this time. The hybrid construction machine according to claim 1, wherein:   A fixed shaft is used as the fixture, the fixed shaft is fixed to one surface of the heat exchange member, and an urging member is disposed between one end of the fixed shaft and the tip of the connection stay, The hybrid construction machine according to claim 1, wherein a compressive force is constantly applied to the heat conductive sheet by a biasing force of a member.   5. The hybrid construction machine according to claim 4, wherein the biasing member includes one or both of a spring or the battery cell and a spacer having a thermal expansion coefficient larger than that of the fixed shaft.   A fixed shaft is used as the fixture, the fixed shaft is fixed to one surface of the heat exchange member, and a linear actuator is disposed between one end of the fixed shaft and the tip of the connecting stay, and the linear 2. The hybrid construction machine according to claim 1, wherein the compression amount of the heat conductive sheet is increased by extending an actuator, and the linear actuator is contracted at a low temperature to reduce the compression amount of the heat conductive sheet. .   Between the upper stay and the plurality of battery cells, two wedge-shaped spacers are formed which are made of a material having a larger thermal expansion coefficient than the upper stay, the connecting stay and the battery cell, and the slopes are combined to face each other. The hybrid construction machine according to claim 3, wherein