JP5960025B2 - Hybrid excavator - Google Patents

Description

  The present invention relates to a hybrid excavator that assists an engine with an electric motor.

  A hybrid excavator is generally provided with an electric motor (assist motor) that assists an engine that outputs power for driving a hydraulic pump. As the assist motor, a motor generator capable of performing an electric operation and a power generation operation is often used. The assist motor is driven by power from the power storage device to assist the engine. The assist motor is driven by engine power to generate power, and the generated power is stored in the power storage device.

  In general, in a hybrid excavator, an assist motor is driven by electric power stored in a storage battery (battery) or a capacitor (capacitor) of the power storage device. Therefore, the hybrid excavator must have a portion on which such a power storage device is mounted.

  Here, the basic structure of the hybrid excavator is the structure of a conventional engine-driven hydraulic excavator, and a structure in which an assist motor, a power storage device, a control device for controlling these, and the like are added to the conventional engine-driven hydraulic excavator. It has become. Therefore, it is necessary to secure a place for mounting a power storage device including a storage battery (battery) or a capacitor (capacitor) somewhere on the upper swing body of the excavator.

  Therefore, considering various conditions including the arrangement of the engine, drive mechanism, cooling mechanism, etc. mounted on the upper swing body, when viewed from the driver seated in the driver's seat in the right front of the cabin where the driver's seat is provided It has been proposed to arrange a power storage device in a portion that is shaded by the base portion of the boom (see, for example, Patent Document 1).

JP 2011-122307 A

  In the hybrid excavator described in Patent Literature 1, the upper surface of the housing that covers the power storage device is approximately the same height as the upper surface of the upper swing body in accordance with the size of the power storage device. For this reason, when viewed from the driver seated in the driver's seat, the upper corner portion of the housing that covers the power storage device protrudes greatly from the shadow of the boom, which hinders the driver's view.

  In addition, the portion where the power storage device is mounted is a portion where a step for the operator to step on the upper swing body is provided when the operator performs a maintenance operation. The height and size of the step-like step are standardized, and it is necessary to provide a step-like step having a predetermined size (area) and height. Since the housing having a height that covers the power storage device has a substantially rectangular parallelepiped shape, it is necessary to attach a dedicated step plate having a size that meets the standard so as to protrude from the side surface of the housing that covers the power storage device.

  The present invention has been made in view of the above-described problem, and a hybrid excavator having a power storage device arranged so as not to attach a dedicated step plate while suppressing an obstacle to the driver's view. The purpose is to provide.

  According to the present invention, an upper swing body having a frame and a main body cover for housing a mounted component, an engine disposed in the main body cover of the upper swing body, a motor generator for assisting the engine, A power storage device that supplies power to the motor generator; and a power storage device cover that houses the power storage device, wherein the power storage device cover has a top surface that extends to a position lower than a top surface of the main body cover. The first cover extends from the vicinity of the back of the driver seat provided on the upper swing body to the vicinity of the front end of the console when the upper swing body is viewed from the side. A hybrid excavator is provided in which at least a part of the apparatus is disposed in a first space formed by the first cover and the frame of the upper swing body.

  According to the above-described invention, there is provided a hybrid excavator having a power storage device that is arranged such that it is not necessary to attach a dedicated step while suppressing an obstacle to the driver's view.

1 is a side view of a hybrid excavator according to an embodiment of the present invention. It is a block diagram which shows the structure of the drive system of the hybrid shovel shown in FIG. It is a circuit diagram of a power storage device. It is a top view of the upper revolving structure which has a cabin. It is a side view of the upper revolving structure in which the power storage device is mounted. It is sectional drawing of an electrical storage apparatus cover. It is a block diagram which shows the structure of a cooling mechanism.

  Next, embodiments will be described with reference to the drawings.

  FIG. 1 is a side view of a hybrid excavator according to an embodiment of the present invention.

  An upper swing body 3 is mounted on a lower traveling body 1 of the hybrid excavator shown in FIG. A boom 4 is attached to the upper swing body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 is attached to the tip of the arm 5. The boom 4, the arm 5, and the bucket 6 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, respectively. The upper swing body 3 is provided with a cabin 10 having a driver's seat, and is mounted with a power source such as an engine and a drive mechanism.

  FIG. 2 is a block diagram showing the configuration of the drive system of the hybrid excavator shown in FIG. In FIG. 2, the mechanical power system is indicated by a double line, the high-pressure hydraulic line is indicated by a solid line, the pilot line is indicated by a broken line, and the electric drive / control system is indicated by a solid line.

  An engine 11 as a mechanical drive unit and a motor generator 12 as an assist drive unit are respectively connected to two input shafts of a transmission 13. A main pump 14 and a pilot pump 15 are connected to the output shaft of the transmission 13 as hydraulic pumps. A control valve 17 is connected to the main pump 14 via a high pressure hydraulic line 16. The hydraulic pump 14 is a variable displacement hydraulic pump, and can control the discharge flow rate by adjusting the stroke length of the piston by controlling the angle (tilt angle) of the swash plate.

  The control valve 17 is a control device that controls the hydraulic system in the hybrid excavator. The hydraulic motors 1A (for right) and 1B (for left), the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 for the lower traveling body 1 are connected to the control valve 17 via a high-pressure hydraulic line.

  The motor generator 12 is connected to a power storage device 120 including a capacitor (capacitor) through an inverter 18A. An operation device 26 is connected to the pilot pump 15 through a pilot line 25. The operating device 26 includes a lever 26A, a lever 26B, and a pedal 26C. The lever 26A, the lever 26B, and the pedal 26C are connected to the control valve 17 and the pressure sensor 29 via hydraulic lines 27 and 28, respectively. The pressure sensor 29 is connected to a controller 30 that performs drive control of the electric system.

  The hybrid excavator shown in FIG. 2 is one in which the turning mechanism 2 of the upper turning body 3 is electrically driven, and a turning electric motor 21 is provided to drive the turning mechanism 2. A turning electric motor 21 as an electric work element is connected to a power storage device 120 via an inverter 20. A resolver 22, a mechanical brake 23, and a turning transmission 24 are connected to the rotating shaft 21 </ b> A of the turning electric motor 21. The turning electric motor 21, the inverter 20, the resolver 22, the mechanical brake 23, and the turning transmission 24 constitute a load drive system.

  The controller 30 is a control device as a main control unit that performs drive control of the hybrid excavator. The controller 30 is configured by an arithmetic processing unit including a CPU (Central Processing Unit) and an internal memory, and is realized by the CPU executing a drive control program stored in the internal memory.

  The controller 30 converts the signal supplied from the pressure sensor 29 into a speed command, and performs drive control of the turning electric motor 21. The signal supplied from the pressure sensor 29 corresponds to a signal indicating an operation amount when the operation device 26 is operated to turn the turning mechanism 2.

  The controller 30 performs operation control (switching between electric (assist) operation or power generation operation) of the motor generator 12 and also drives and controls the step-up / down converter 100 (see FIG. 3) as a step-up / down control unit. Charge / discharge control. The controller 30 is a step-up / down converter based on the charged state of the capacitor 19, the operating state of the motor generator 12 (electric (assist) operation or generating operation), and the operating state of the turning motor 21 (power running operation or regenerative operation). Switching control between 100 step-up operations and step-down operations is performed, and thereby charge / discharge control of the capacitor 19 is performed. In addition, the controller 30 calculates the charge rate SOC of the capacitor 19 based on the capacitor voltage value detected by the capacitor voltage detector.

  FIG. 3 is a circuit diagram of the power storage device 120. The power storage device 120 includes a capacitor 19 as a power storage, a buck-boost converter, and a DC bus 110. The DC bus 110 controls transmission and reception of electric power among the capacitor 19, the motor generator 12, and the turning electric motor 21. The capacitor 19 is provided with a capacitor voltage detector 112 for detecting the capacitor voltage value and a capacitor current detector 113 for detecting the capacitor current value. The capacitor voltage value and the capacitor current value detected by the capacitor voltage detection unit 112 and the capacitor current detection unit 113 are supplied to the controller 30.

  The step-up / step-down converter 100 performs control to switch between the step-up operation and the step-down operation so that the DC bus voltage value falls within a certain range according to the operation state of the motor generator 12 and the turning electric motor 21. The DC bus 110 is disposed between the inverters 18 </ b> A and 20 and the step-up / down converter 100, and transfers power between the capacitor 19, the motor generator 12, and the turning electric motor 21.

  Switching control between the step-up / step-down operation of the buck-boost converter 100 is performed by the DC bus voltage value detected by the DC bus voltage detection unit 111, the capacitor voltage value detected by the capacitor voltage detection unit 112, and the capacitor current detection unit 113. This is performed based on the detected capacitor current value.

  In the configuration as described above, the electric power generated by the motor generator 12 that is an assist motor is supplied to the DC bus 110 of the power storage device 120 via the inverter 18A, and is supplied to the capacitor 19 via the buck-boost converter 100. . The regenerative power generated by the regenerative operation of the turning electric motor 21 is supplied to the DC bus 110 of the power storage device 120 via the inverter 20 and supplied to the capacitor 19 via the step-up / down converter 100.

  Capacitor 19 may be a chargeable / dischargeable capacitor so that power can be exchanged with DC bus 110 via buck-boost converter 100. In this embodiment, the capacitor 19 is used as a capacitor. However, instead of the capacitor 19, a secondary battery that can be charged and discharged, such as a lithium ion battery, a lithium ion capacitor, or any other device that can exchange power. A form of power supply may be used.

  In the hybrid excavator configured as described above, the power storage device 120 is mounted on the upper swing body 3. The position where the power storage device 120 is mounted will be described below.

  FIG. 4 is a plan view of the upper swing body 3 having the cabin 10. FIG. 5 is a side view of the upper swing body 3 on which the power storage device 120 is mounted.

  As shown in FIG. 4, when the upper swing body 3 is viewed from above, the main body cover 40 in which the engine 11 and the driving mechanism are accommodated is provided on the rear side, and the cabin 10 in which the driver's seat 50 is provided is provided on the main body cover 40. Is provided in front of the left side. Here, the front is the direction in which the driver's seat 50 is facing, that is, the direction in which the driver seated on the driver's seat 50 is facing. The left side is the left side of the driver when the driver is seated on the driver's seat 50 (that is, toward the front).

  The cabin 10 is provided with the driver's seat 50 as described above, and the driver's seat 50 has a backrest 50a so as to be stably held at the position where the driver is seated. A console 54 provided with an operation lever 26A, a button switch 26D, and the like is disposed on the right side of the driver seat 50. The driver usually operates by grasping the operation lever 26A protruding from the console 54 with the right hand while sitting in the driver's seat 50 and putting his back on the backrest 50a and being in a stable state.

  The base of the boom 4 is pivotally attached to the frame 42 of the upper swing body 3 at substantially the left and right centers on the front side of the upper swing body 3. 4 and 5, only a part of the root part of the boom 4 is shown. Moreover, the schematic to the bucket is shown with the broken line.

  On the opposite side of the cabin 10 across the boom 4, the frame 42 of the upper swing body 3 extends forward in the same manner as the cabin 10, and the power storage device 120 is mounted on the extended frame 42. The power storage device 120 is covered with the right front cover 60.

  Here, in the conventional hybrid excavator, the right front cover covering the power storage device protrudes to the same height as the main body cover 40a as shown by a thick dotted line in FIG. In such a situation, as shown in FIG. 4, the field of view from the operator can ensure only an angle from the bucket to θα. For this reason, when the operator performs a right turn, it is necessary to carefully operate the lever, which reduces work efficiency.

  In the present embodiment, the right front cover 60 includes an upper cover (first cover) 62 and a lower cover (second cover) 64. That is, the right front cover 60 is formed by the upper cover 62 and the lower cover 64. The upper surface 62a of the upper cover 62 is lower than the upper surface 40a of the main body cover 40, and the upper surface 64a of the lower cover 64 is lower than the upper surface 62a of the upper cover 62. A step plate 44 extends from the front edge of the frame 42, and the upper surface 44 a of the step plate 44 is slightly lower than the upper surface of the frame 42.

  Accordingly, when viewed from the upper surface 44 a of the step plate 44 having the same height as the upper surface of the frame 42, the step shape increases from the upper surface 64 a of the lower cover 64 to the upper surface 62 a of the upper cover 62 and to the upper surface 40 a of the main body cover 40. The structure is formed. In this step-like structure, the height (distance) from the upper surface 44a of the step plate 44 to the upper surface 64a of the lower cover 64 is set to 230 mm to 400 mm so as to satisfy the dimensions defined by the standard. Similarly, the height (distance) from the upper surface 64a of the lower cover 64 to the upper surface 62a of the upper cover 62, and the height (distance) from the upper surface 62a of the upper cover 62 to the upper surface 40a of the main body cover 40 are also 230 mm to 400 mm. Is set to The width of the step plate 44 (the length of the portion extending forward from the lower cover 64), the width of the upper surface 64a of the lower cover 64 (the length of the portion extending forward from the front side surface of the upper cover 62), The width of the upper surface 62a of the upper cover 62 (the length extending forward from the front side surface of the main body cover 40) is set to 150 mm or more.

  Due to the above-described stepped structure formed by the right front cover 60, for example, the maintenance operator steps on the upper surface 44a of the step plate 44, the upper surface 64a of the lower cover 64, and the upper surface 62a of the upper cover 62 in order. Thus, it is possible to easily climb up to the upper surface 40a of the main body cover 40, and maintenance work can be performed on the main body cover 40.

  The height of the right front cover 60 is the height of the upper surface 62a of the upper cover 62, and is 230 mm to 400 mm lower than the height of the upper surface 40a of the main body cover 40. The upper surface of the upper cover 62 extends from the vicinity of the backrest 50a of the driver's seat 50 to the vicinity of the front end of the console 54 in the cabin 10 when the upper swing body 3 (that is, the cabin 10) is viewed from the side. ing. Therefore, when viewed from the driver seated in the driver's seat 50 of the cabin 10, the right front cover 60 is housed in the shadowed portion of the boom 4, and the visibility in the height direction is not hindered by the right front cover 60. As a result, as shown in FIG. 4, the field of view from the operator can secure an angle from the bucket to θβ, and the field of view on the right front side of the shovel can be sufficiently secured. For this reason, when the operator performs a right turn, the lever can be greatly tilted to perform a turning operation, and work efficiency can be improved.

  Further, the upper cover 62 of the right front cover 60 is retracted 150 mm or more from the lower cover 64, and the front surface 62b which is the front side surface of the upper cover 62 is the cabin when the upper swing body 3 (that is, the cabin 10) is viewed from the side surface. 10 is located in the vicinity of the front end portion of the console 54 in 10. The position of the front end portion of the console 54 is a position where the driver's eyes are located when the driver is seated on the driver's seat 50. Therefore, the front surface 62b of the upper cover 62 does not extend before the driver's eyes, and the right front cover 60 does not obstruct the driver's field of view (right front field of view).

  Here, the accommodation state of the power storage device 120 inside the right front cover 60 will be described. FIG. 6 is a cross-sectional view of the right front cover 60 in which the power storage device 120 is accommodated.

  A case 122 in which a circuit that forms a control unit including the buck-boost converter 110 is incorporated in a space (first space) inside the upper cover 62 (first cover). In the case 122, the inverter 18A for the motor generator 12 and the inverter 20 for the turning motor may be incorporated.

  The capacitor 19 is disposed in a space (second space) inside the lower cover 64 (second cover). The capacitor 19 is placed on a beam 46 passed between the frames 42 of the upper swing body 3 via a vibration isolation mount 48. A capacitor fixing bracket 19 a is attached to the upper surface of the capacitor 19. The bracket 19a is inserted into and engaged with a through hole formed in the upper plate of the lower cover 64, whereby the capacitor 19 is suspended by the bracket 19a.

  With the above configuration, the capacitor 19 and the case 122 in which the control unit including the step-up / down converter 110 is incorporated can be accommodated in the right front cover 60 and integrated. Therefore, the power storage device 120 can be mounted on the upper swing body 3 simply by attaching the right front cover 60 in which the power storage device 120 is accommodated to the frame 42. Further, the power storage device 120 can be removed from the upper swing body 3 simply by removing the right front cover 60.

  Note that the controller of the power storage device 120 and the capacitor 19 generate heat during driving, and thus need to be cooled. Therefore, in the present embodiment, the power storage device 120 is cooled using a cooling mechanism for cooling the turning electric motor 21 and the motor generator 12.

  FIG. 7 is a block diagram of a cooling mechanism 130 for cooling the turning electric motor 21 and the motor generator 12. The cooling mechanism 130 is mounted on the upper swing body 3 in the main body cover 40. The cooling mechanism 130 is a mechanism that circulates cooling water as a coolant and cools the turning electric motor 21 and the motor generator 12, and includes a cooling pump 134 that is driven by a cooling motor 132.

  The cooling water discharged from the cooling pump 134 first passes through the radiator 136 and is cooled by exchanging heat with the atmosphere, so that the temperature becomes the same level as the atmosphere. A cooling water pipe 140 near the outlet of the radiator 136 is provided with a water temperature gauge 138 for detecting the temperature of the cooling water.

  The cooling water discharged from the radiator 136 is first supplied to the power storage device 120 to cool the power storage device 120 and then supplied to the turning electric motor 21 and the motor generator 12 to cool them. The reason why the cooling water is supplied in this order is that the power storage device 120 needs to be maintained at a temperature lower than that of the turning motor 21 and the motor generator 12, and the amount of heat generated in the power storage device 120 is for turning. This is because the amount of heat generated by the motor 21 and the motor generator 12 is smaller.

  In order to supply the cooling water to the capacitor 19 of the power storage device 120, the case 122 of the buck-boost converter 110, and each of the inverters 18A and 20, the cooling water pipe 140 is branched into four.

  Of the branched pipes, the pipe 142 </ b> A is connected to the capacitor 19. The cooling water supplied from the pipe 142A flows through the capacitor 19 to cool the capacitor 19, and then flows into the pipe 142B.

  Of the branched pipes, the pipe 144A is connected to a case 122 in which the step-up / down converter 110 is incorporated. The cooling water supplied from the pipe 144A flows through the case 122 to cool the step-up / down converter 110 and then flows to the pipe 144B.

  Similarly, similarly branched pipes are connected to the inverter 18A for the motor generator 12 and the inverter 20 for the turning electric motor 21, and the cooling water that has cooled the inverters 18A and 20 is discharged. When inverters 18A and 20 are also incorporated in case 122, inverters 18A and 20 are also cooled with cooling water supplied from piping 144A.

  The cooling water that has cooled the power storage device 120 flows again into one cooling water pipe 140 and is then supplied to the turning electric motor 21 to cool the turning electric motor 21. The cooling water discharged from the turning electric motor 21 is supplied to the motor generator 12 to cool the motor generator 12. The high-temperature cooling water discharged from the motor generator 12 flows into the tank 139 through the cooling water pipe 140. The cooling water is temporarily stored in the tank 139 and is naturally cooled to decrease the temperature to some extent. The cooling water is supplied again to the cooling pump 134 and flows through the cooling water pipe 140 and circulates.

  In order to configure the cooling water circulation path as described above, as shown in FIG. 6, pipes 142A and 142B extending from the main body cover 40 are connected to the capacitor 19, and similarly, the pipes 144A and 144A extending from the main body cover 40 are connected. 144B is connected to case 122.

  Note that the cooling water after cooling the capacitor 19 may be supplied to the case 122 to cool the step-up / down converter 110 and the inverters 18A and 20. In this case, the cooling water discharge port of the capacitor 19 may be connected to the cooling water supply port of the case 122. For example, the cooling water discharged from the capacitor 19 can be supplied to the case 122 by connecting the pipe 142 </ b> B connected to the capacitor 19 and the pipe 144 </ b> A connected to the case 122.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 1A, 1B Hydraulic motor 2 Turning mechanism 3 Upper turning body 4 Boom 5 Arm 6 Bucket 7 Boom cylinder 8 Arm cylinder 9 Bucket cylinder 10 Cabin 11 Engine 12 Motor generator 13 Transmission 14 Main pump 15 Pilot pump 16 High pressure Hydraulic line 17 Control valve 18A, 20 Inverter 19 Capacitor 19a Bracket 21 Turning motor 22 Resolver 23 Mechanical brake 24 Turning transmission 25 Pilot line 26 Operating device 26A, 26B Lever 26C Pedal 27 Hydraulic line 28 Hydraulic line 29 Pressure sensor 30 Controller 40 Main body cover 40a Upper surface 42 Frame 44 Step plate 44 Upper surface 50 Driver's seat 50a Backrest 54 Console 60 Right front cover 62 Upper cover Bar 62a Upper surface 62b Front surface 64 Lower cover 64a Upper surface 100 Buck-boost converter 110 DC bus 111 DC bus voltage detection unit 112 Capacitor voltage detection unit 113 Capacitor current detection unit 120 Power storage device 130 Cooling mechanism 132 Cooling motor 134 Cooling pump 136 Radiator 138 Water thermometer 139 Tank 140 Cooling water piping 142A, 142B, 144A, 144B piping

Claims (11)

An upper swing body having a frame and a main body cover for housing the mounted components;
An engine disposed in the main body cover of the upper swing body;
A motor generator for assisting the engine;
A power storage device for supplying power to the motor generator;
A right front cover for housing the power storage device,
The right front cover includes a first cover having an upper surface extending to a position lower than the upper surface of the main body cover,
The first cover extends from the vicinity of the back of the driver's seat provided in the upper swing body to the vicinity of the front end of the console when the upper swing body is viewed from the side surface.
Wherein at least a portion of said power storage device is disposed in a first space formed between the frame of the upper rotating body and the first cover,
A hybrid excavator, wherein a control unit including a converter that controls charging / discharging of the power storage device is disposed integrally with the power storage device in the first space . The hybrid excavator according to claim 1 ,
The hybrid excavator, wherein the upper surface of the first cover extends at a position lower than the upper surface of the main body cover with a height difference of 230 mm or more and 400 mm or less. A hybrid excavator according to claim 1 or 2 ,
A hybrid excavator having a length of a portion of the upper surface of the first cover extending forward from the front surface of the main body cover is 150 mm or more. A hybrid excavator according to any one of claims 1 to 3 ,
The hybrid excavator, wherein the first cover includes a second cover having an upper surface lower than an upper surface of the first cover. A hybrid excavator according to claim 4 ,
A second space formed by a second cover having an upper surface lower than the upper surface of the first cover and the frame of the upper swing body is formed, and at least a part of the power storage device is the second space. Hybrid excavator placed in The hybrid excavator according to claim 5 ,
A hybrid excavator in which a power storage unit of the power storage device is disposed in the second space. A hybrid excavator according to any one of claims 1 to 6 ,
A coolant circulation system including at least a pump, a radiator, a tank, and a coolant pipe connecting them is provided in the main body cover of the upper rotating body,
The hybrid excavator, wherein the coolant pipe is connected to a rear end side of the power storage device, and the power storage device is cooled by the coolant circulation system. A hybrid excavator according to claim 7 ,
The hybrid excavator in which the coolant pipe of the coolant circulation system is also connected to the rear end side of the control unit. A hybrid excavator according to claim 8 ,
The coolant hybrid shovel which is connected to the pipe passing through the converter and the cooling liquid pipe through said power storage device. A hybrid excavator according to any one of claims 5 to 9 ,
A second cover having a top surface lower than the top surface of the first cover extends to within the first cover, said converter及beauty inverter is disposed on the second cover in the first in the cover Hybrid excavator. The hybrid excavator according to claim 10 ,
The power storage unit of the power storage device includes a bracket that extends through the second cover to the first space, the bracket is fixed to the second cover, and the power storage unit is A hybrid excavator attached to a cover, wherein the first cover, the control unit, the second cover, and the power storage unit are integrally attached to and detached from the frame.

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