JP6106831B2 - Hybrid compact hydraulic excavator - Google Patents

Description

The present invention relates to a hybrid compact hydraulic excavator that has two types of power sources, for example, an engine and a generator / motor, and uses these two types of power sources as appropriate depending on the situation.

  A hydraulic excavator, which is a typical example of a construction machine, is hybridized by providing two types of power sources, that is, an engine and a power generation / motor, in order to improve fuel consumption, clean exhaust gas, and the like.

  The hybrid hydraulic excavator includes a self-propelled lower traveling body, an upper revolving body mounted on the lower traveling body via a revolving device using a power generator / motor for turning as a power source, and the upper revolving body It is comprised by the working apparatus provided in the front side of the revolving body so that it can be moved up and down using a hydraulic actuator as a power source.

  On the other hand, the upper swing body includes a swing frame that forms a support structure, a counterweight that is attached to a rear end of the swing frame and that balances the weight of the working device, and is positioned on the front side of the counterweight. An engine mounted in a lateral state extending in the left and right directions on the rear side of the frame, a hydraulic pump whose input shaft is coaxially provided with the output shaft of the engine and driven by the engine, and an output of the engine An assisting generator / motor connected to the shaft and the input shaft of the hydraulic pump, and a footrest portion supported by the front of the swivel frame on one side of the left and right directions so as to be tiltable and on which an operator can put his / her foot A floor member comprising a rising portion that rises upward from the rear portion of the footrest portion, and a driver seat mounting portion that extends rearward from the upper side of the rising portion toward the upper side of the engine; An oil storage tank that is provided on the other side of the left and right directions of the engine, and stores fuel or hydraulic oil therein, and supplies power to the turning generator / motor and the assist generator / motor. A power generator / motor and a power storage device that receives power from the assist generator / motor, a turning inverter connected to the generator / motor to control the turning generator / motor, and the assist And an assisting inverter connected to the generator / motor for controlling the generator / motor (see, for example, Patent Document 1). In general, a contactor for connecting and disconnecting between the turning inverter and the assisting inverter and the power storage device is provided.

JP 2007-106209 A

  By the way, the hydraulic excavator has a small hydraulic excavator called a mini excavator in which the operating mass as a total weight during operation is set to less than 6 tons. In this small hydraulic excavator, the upper swing body is downsized. Yes. In particular, even in small hydraulic excavators, a rear ultra-small swivel type that is configured so that the upper revolving unit can swivel within the vehicle width dimension of the lower traveling unit so that it can swivel in a narrow work site. In a hydraulic excavator called a small turning type, the upper turning body is further miniaturized.

  Here, when a hydraulic excavator is hybridized, it is desirable to newly develop a dedicated machine. However, in order to provide hybrid hydraulic excavators to the market at an early stage, existing hydraulic excavators are utilized, and various electric parts for hybridization, such as power generators / motors, power storage devices, and swivel inverters, are used for the hydraulic excavators. Changing the design so that an inverter for an engine, a contactor, etc. can be mounted is a shortcut for hybridization.

  On the other hand, in the existing excavator, as described above, the upper swing body is further reduced in size, so various electric parts for hybridization are mounted around the engine, the hydraulic pump, the oil storage tank, and the like. There is a problem that is difficult.

The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to enable easy mounting of various electrical components for hybridizing to the upper swing body even in a small upper swing body. It is to provide a hybrid type small hydraulic excavator .

Hybrid compact hydraulic excavator according to the present invention includes a lower traveling body of self-propelled crawler type, a swing motor-generator on the lower traveling structure mounted pivotably via a pivoting device for a power source turning operation An upper revolving body whose rear part is within the vehicle width of the crawler type lower traveling body, and a working device provided on the front side of the upper revolving body so as to be able to move up and down using a hydraulic actuator as a power source. The swivel body includes a swivel frame that forms a support structure, a counterweight that is attached to a rear end of the swivel frame and balances the weight of the working device, and is located on the front side of the counterweight and is located behind the swivel frame. Engine mounted horizontally and extending in the left and right directions on the side, and a hydraulic pump driven by the engine provided with an input shaft coaxially with the output shaft of the engine , An output shaft and said hydraulic pump input shaft and connected to the assist motor-generator of the engine, the left of the rotating frame, tilt up through the tilting support member to the front of one side of the right direction, is supported tilt-down capable, the footrest section, the rising portion rises upward from the rear of the foot put portion, the driver's seat mounting portion extending from the upper side of the rising portion rearward toward the upper side of the engine, And a floor member comprising a mounting plate portion that is attached to the counterweight and extends to the rear side of the driver seat mounting portion, and is provided on the other side in the left and right directions of the swivel frame, and fuel or hydraulic oil is provided therein. Supplying electric power to the oil storage tank to be stored, the turning generator / motor and the assist generator / motor, and power from the turning generator / motor and the assist generator / motor A power storage device for receiving power, a turning inverter connected to the power generator / motor for controlling the power generator / motor for turning, and a power inverter / motor for controlling the assist power generator / motor An assist inverter provided in a connected manner, and a contactor provided between the turning inverter and the assist inverter and the power storage device and connected and disconnected between the two.

In order to solve the above-described problem, the feature of the configuration of the invention of claim 1 is that the turning inverter, the assisting inverter, and the contactor are below the driver seat mounting portion of the floor member, and It is formed between the engine and the rising portion of the floor member, and is configured to be disposed in a space in front of the engine that is opened to the outside in a state where the floor member is tilted up . An electrical component mounting bracket is provided that is located in the space in front of the engine and is a member different from the floor member, and the turning inverter, the assist inverter, and the contactor are configured to be mounted on the electrical component mounting bracket. It is in.

The invention of claim 2, wherein the turning inverter, assisted inverter and the contactors is that the left, Ru configuration are arranged to the right and to the engine front space.

A third aspect of the present invention, the electric storage device is to have a structure that will be disposed to on the revolving frame positioned between the floor member and the oil storage tank.

The invention according to claim 4, wherein the power storage device, wherein are arranged on the revolving frame positioned between the floor member and the oil storage tank, the swing inverter and the assist inverter is a plan view in has been arranged in a position close to the power storage device, the contactor is to have a configuration in which the Ru disposed at a position separated from the electric storage device than the inverters.

According to a fifth aspect of the invention, the output of the engine covers the force required to drive the hydraulic pump with a light load, and when the load of the hydraulic pump becomes larger than the light load, the output of the engine Further, the output of the assist generator / motor is assisted.

The invention of claim 6, the output of the engine is set to a required value to drive the hydraulic pump during low speed traveling or during normal work, at the time of high speed running, the assist for the output of the engine In other words, the hydraulic pump is driven by assisting the output of the generator / motor.

According to the first aspect of the present invention, the driver seat mounting portion constituting the floor member is opened to the outside with the floor member tilted up and positioned between the rising portion of the floor member and the engine. An engine front space is formed. In the space in front of the engine, a turning inverter, an assisting inverter, and a contactor used when a small hydraulic excavator is hybridized can be arranged.

As a result, when using existing construction machinery and hybridizing this construction machinery, especially when hybridizing a small hydraulic excavator that is difficult to secure the installation space of equipment on the upper swing body, the engine By using the front space, a turning inverter, an engine inverter, and a contactor can be easily mounted.
Moreover, by attaching the turning inverter, the assisting inverter, and the contactor to the electrical component mounting bracket made of a member different from the floor member, these electrical components can be attached to the turning frame as one electrical component unit. As a result, the turning inverter, the assisting inverter, and the contactor can be easily provided in the space in front of the engine via the electrical component mounting bracket, and the assembly workability and the maintenance workability can be improved.

  According to the invention of claim 2, in the space in front of the engine, the turning inverter, the assisting inverter and the contactor are arranged side by side in the left and right directions. Thereby, in a state where the floor member is tilted so as to lift the rear side, the space in front of the engine can be largely opened to the outside. Therefore, by utilizing the largely open engine space, it is possible to improve workability when connecting the inverter for turning, the inverter for assisting, and the contactor, and maintenance workability such as inspection and repair.

According to the invention of claim 3 , the power storage device is disposed between the floor member and the oil storage tank, so that the turning inverter disposed in the space in front of the engine between the engine and the rising portion of the floor member, It can be arranged at a position close to the assist inverter and the contactor. Thus, the power storage device and the turning inverter, the assisting inverter, and the contactor can be easily connected using a short cable.

According to the invention of claim 4 , the power storage device is disposed between the floor member and the oil storage tank, so that the turning inverter disposed in the space in front of the engine between the engine and the rising portion of the floor member, It can be arranged at a position close to the assist inverter and the contactor.

  On this basis, the turning inverter and the assisting inverter are arranged side by side at a position closer to the power storage device in plan view, and the contactor is disposed at a position farther from the power storage device than the inverters.

  Therefore, a short power cable is used to connect the turning generator / motor arranged near the center of the turning frame and the turning inverter, and between the assisting generator / motor provided in the engine and the assist inverter. be able to. Thus, by shortening the cable through which a large current flows, deterioration of the cable due to heat generation or the like can be suppressed, and reliability can be improved. Furthermore, the power storage device and the turning inverter, the assisting inverter, and the contactor can be easily connected using a short cable.

According to the invention of claim 5 , since the output of the engine is set to cover the force required to drive the hydraulic pump with a light load, the engine has a small output (small displacement). Things can be used. Thereby, with respect to the exhaust gas regulation for purifying the exhaust gas, it is possible to reduce the burden due to the regulation by suppressing the output of the engine to the outside of the regulation target, and it is possible to hybridize at a low cost. In addition, since the engine with a small output is formed in a small size as a whole, it is possible to secure a space for arranging the devices around the engine, and in addition to the downsizing of the engine, the upper swing body Can be reduced in size. On the other hand, the fuel consumption rate can be improved by using a small (small displacement) engine. Further, when the hydraulic pump is driven with a heavy load larger than a light load, the hydraulic pump can be driven by assisting the output of the engine with the output of the assisting generator / motor.

According to the sixth aspect of the present invention, the hydraulic pump can be driven only by the output of the engine during low speed traveling or normal work. On the other hand, when traveling at high speed, the load pressure of the hydraulic pump increases, and the hydraulic pump cannot be driven only by the output of the engine. Therefore, by assisting the output of the assist generator / motor with the output of the engine, a hydraulic pump having a large load pressure can be driven.

1 is a front view showing a hybrid compact hydraulic excavator according to an embodiment of the present invention. It is a left view which shows the hybrid type small hydraulic excavator which abbreviate | omitted the working apparatus from the front side. It is a top view which shows the hybrid type small hydraulic excavator which abbreviate | omitted the working apparatus and the exterior cover. It is a perspective view which expands and shows the upper turning body which abbreviate | omitted the cab box, the driver's seat, etc. It is a perspective view which abbreviate | omits a floor member from the upper turning body shown in FIG. It is a disassembled perspective view which shows the upper revolving body of FIG. 5 in the state which removed the heat exchanger cover, the electrical component unit, and the exterior cover. FIG. 5 is an enlarged front view showing the upper swing body in FIG. 4 with the floor member in a cross-sectional state. It is a top view which shows a single turning frame. It is a perspective view which expands and shows a single floor member. It is a top view of the upper revolving body which omitted a floor member, an exterior cover, etc. which show a connection state of each power generator / motor, an electrical storage device, each inverter, and a contactor box. It is a disassembled perspective view of the principal part expansion which shows the attachment structure of the electrical component unit with respect to a turning frame and a counterweight. It is a disassembled front view of the principal part expansion which shows the attachment structure of the electrical component unit with respect to a turning frame and a counterweight. It is a disassembled perspective view which shows an electrical component unit in the state which isolate | separated the upper side attachment part and lower side attachment part of the bracket for electrical components. It is a characteristic diagram which shows the relationship between the output characteristic of an engine, the output characteristic of a generator / motor, and the characteristic of a hydraulic pump. It is a characteristic line figure which shows the output characteristic of an engine and a generator / motor. It is a block diagram which shows the operation system of a hybrid type small hydraulic excavator.

Hereinafter, a hybrid type small hydraulic excavator according to an embodiment of the present invention, an example of the hybrid type small hydraulic excavator using a combination of the engine and the generator-motor as a power source, in detail with reference to FIGS. 1 to 16 explain.

In Figure 1, 1 denotes a hybrid type small hydraulic excavator. The hybrid small hydraulic excavator 1 (hereinafter referred to as a hybrid hydraulic excavator 1) is called a mini excavator having an operating mass of less than 6 tons, for example. The hydraulic excavator is a rear ultra-small swivel excavator that is substantially within the width dimension.

  As shown in FIGS. 1 to 3, the hybrid excavator 1 includes a crawler-type lower traveling body 2 that can be self-propelled, a turning device 3 provided on the lower traveling body 2, and the lower traveling body 2. The upper revolving unit 4 is mounted on the upper revolving unit 4 so as to be able to revolve through the revolving unit 3, and the working unit 5 is provided on the front side of the upper revolving unit 4 so as to be able to move up and down, and performs soil excavation work and the like. ing.

  The lower traveling body 2 includes a track frame 2A, drive wheels 2B provided on the left and right sides of the track frame 2A, and the front and rear sides of the drive wheel 2B. An idler wheel 2C provided on both the left and right sides, and a crawler belt 2D wound around the drive wheel 2B and the idler wheel 2C (both shown only on the left side) are configured. The left and right drive wheels 2B are rotationally driven by left and right traveling motors 2E and 2F (see FIG. 16), which are hydraulic motors, so that the lower traveling body 2 can be self-propelled. On the other hand, on the upper side of the central portion of the track frame 2A, a large-diameter and short cylindrical body 2G is provided, and the turning device 3 is attached on the cylindrical body 2G. Here, for example, the traveling motors 2E and 2F of the lower traveling body 2 can switch the traveling speed between two stages of a low speed stage and a high speed stage.

  The working device 5 includes a boom 5A attached to a revolving frame 6 to be described later so as to be able to move up and down, an arm 5B attached to the tip of the boom 5A so as to be able to move up and down, and rotatable to the tip of the arm 5B. And a boom cylinder 5D, an arm cylinder 5E, and a bucket cylinder 5F which are hydraulic cylinders as hydraulic actuators for driving the bucket 5C.

  The upper swing body 4 has a swing frame 6 (described later) mounted on the lower traveling body 2 via the swing device 3 so as to be swingable. On the swing frame 6, a counterweight 8, an engine 11, and a hydraulic pump 13 (described later). , Generator / motor 14 for assist, generator / motor 15 for swing, floor member 16, hydraulic oil tank 22, fuel tank 23, power storage device 24, electrical component mounting bracket 27, inverter 34 for swing, inverter 36 for assist, contactor box 37 etc. are provided.

  A revolving frame 6 forms a support structure for the upper revolving structure 4. As shown in FIGS. 4 to 8, the swivel frame 6 is erected on the bottom plate 6A extending in the front and rear directions, and on the bottom plate 6A extending in the front and rear directions with an interval in the left and right directions. A left vertical plate 6B, a right vertical plate 6C, a left side frame 6D that extends from the front end portion of the bottom plate 6A to the left and to the left in the right direction and is bent and extended rearward, and a left and right from the front end portion of the bottom plate 6A. A right side frame 6E that is bent while extending to the right in the direction and extends rearward, and extends to the left and right on the bottom plate 6A while being fixed to the rear ends of the vertical plates 6B and 6C. The rear horizontal plate 6F, the C-shaped or U-shaped rear vertical plate 6G standing on the bottom plate 6A and positioned on the rear side of the rear horizontal plate 6F, and the vertical plates 6B and 6C. And a support bracket 6H provided on the front side. The support bracket 6H is provided so as to protrude forward from the bottom plate 6A, and the working device 5 is attached to the distal end side so as to be swingable in the left and right directions.

  On the other hand, as shown in FIGS. 11 and 12, a plurality of, for example, 2 to 5 female screw holes 6J, located between the left and right vertical plates 6B and 6C, are provided in the upper portion of the rear horizontal plate 6F. Are provided at intervals in the left and right directions. The plurality of female screw holes 6J are formed, for example, as weld nuts in which nuts are welded to through holes formed in the rear lateral plate 6F. Here, the rear horizontal plate 6F attaches an electrical component mounting bracket 27 described later in cooperation with a floor mounting bracket 9 of the counterweight 8 described later. The electrical component mounting bracket 27 is installed in each female screw hole 6J. A bolt 33 for attaching the lower portion of the lower portion is screwed.

  Reference numeral 7 denotes a power storage device mounting base provided on the revolving frame 6. The power storage device mounting base 7 mounts a power storage device 24 described later on the revolving frame 6, and constitutes a part of the revolving frame 6. Yes. The power storage device mounting base 7 is formed as a box-shaped base that extends from the front end of the right side frame 6E to the rear horizontal plate 6F near the center of the revolving frame 6, specifically, the upper position of the right vertical plate 6C. The box-shaped power storage device mounting base 7 has a flat mounting surface portion 7A for mounting the power storage device 24 on the upper surface, and a front surface portion 7B extending downward from the front end of the mounting surface portion 7A has a cable 38 and the like to be described later. An opening 7 </ b> C for passing through is formed.

  Reference numeral 8 denotes a counterweight attached to the rear end of the revolving frame 6. The counterweight 8 balances the weight with the working device 5 and has a convex curved shape protruding rearward. As shown in FIG. 11, the upper end surface of the counterweight 8 is a substantially flat upper surface 8A, and a floor mounting bracket 9 constituting a part of the counterweight 8 is provided on the front side of the upper surface 8A.

  Here, the floor mounting bracket 9 is attached to the rear side of a floor member 16 to be described later. The floor mounting bracket 9 is a strength member having an L-shaped cross section composed of a horizontal plate portion 9A extending horizontally in the left and right directions and a vertical plate portion 9B bent downward from the front end of the horizontal plate portion 9A and extending downward. Is formed. The horizontal plate portion 9A is integrally bolted to the upper surface 8A of the counterweight 8. On the other hand, the vertical plate portion 9B is provided with a plurality of, for example, three female screw holes 9C at intervals in the left and right directions, and these three female screw holes 9C are, for example, the female screws of the revolving frame 6 described above. Like the hole 6J, it is formed as a welding nut. Further, a bolt 33 for attaching the upper portion of the electrical component mounting bracket 27 is screwed into each female screw hole 9C.

  Reference numeral 10 denotes a heat exchanger cover provided on the right side of the floor mounting bracket 9 and extending from the counterweight 8 to the front side. The heat exchanger cover 10 includes an upper surface portion 10A that covers an upper side of the engine 11 and the heat exchanger 12 described later, and extends downward from the front side of the upper surface portion 10A to cover the front side of the engine 11 and the heat exchanger 12. For example, the lower side of the front surface portion 10B is attached to the rear portion of the power storage device mounting base 7.

  Reference numeral 11 denotes an engine provided on the revolving frame 6 that is located on the front side of the counterweight 8. The engine 11 is mounted on a rear vertical plate 6G located on the rear side of the revolving frame 6 in a horizontally placed state extending in the left and right directions. The engine 11 is provided with an exhaust pipe 11 </ b> A for exhausting exhaust gas, and the exhaust pipe 11 </ b> A is provided with a muffler 11 </ b> B located on the left side of the engine 11. The muffler 11B is provided to reduce the noise of the exhaust gas. In addition to this, when the output of the engine 11 exceeds the set value of the exhaust gas regulation, the muffler 11B is changed to an exhaust gas aftertreatment device to remove harmful substances in the exhaust gas discharged from the engine 11. can do. On the other hand, a heat exchanger 12 including a radiator, an oil cooler and the like is disposed on the right side of the engine 11.

  Here, the performance (output) of the engine 11 will be described. As shown in FIG. 15, the output of the engine 11 is set to a magnitude that can cover the force required to drive a hydraulic pump 13 described later with a light load. Specifically, the output of the engine 11 is normal when the lower traveling body 2 is traveling at a low speed or when a general excavation operation is performed using the working device 5 and the turning device 3. The value required for driving the hydraulic pump 13 during the operation is set. On the other hand, when the load on the hydraulic pump 13 becomes larger than the light load, for example, when the lower traveling body 2 is traveling at a high speed, the assist generator / motor 14 is output with respect to the output of the engine 11. The hydraulic pump 13 is driven by assisting the output.

  Therefore, the engine 11 only needs to have an output capable of driving the hydraulic pump 13 with a light load. Therefore, the engine 11 can be downsized in accordance with the output, and a device related to the engine 11 such as a muffler 11B (after exhaust gas) The processing apparatus), the heat exchanger 12 and the like can also be reduced in size. Thus, a space including an engine front space 26 described later can be provided around the engine 11 by downsizing each device.

  Reference numeral 13 denotes a hydraulic pump provided on the left side of the engine 11. The hydraulic pump 13 is provided with an input shaft coaxial with the output shaft of the engine 11 and is driven by the engine 11. The hydraulic pump 13 boosts and discharges hydraulic oil as a power source for driving the traveling motors 2E, 2F of the lower traveling body 2 and the cylinders 5D, 5E, 5F of the work device 5.

  Here, as shown in FIG. 14, the output required to drive the hydraulic pump 13 with a light load can be covered by the output of the engine 11. On the other hand, the output required to drive the hydraulic pump 13 with a load heavier than this can be provided by adding (assisting) the output of the assist generator / motor 14 described later to the output of the engine 11. .

  Reference numeral 14 denotes an assist generator / motor (see FIG. 11) that is located on the left side of the engine 11 and is connected to the output shaft of the engine 11 and the input shaft of the hydraulic pump 13. The assist generator / motor 14 generates power by being rotationally driven by the engine 11 or assists the drive of the hydraulic pump 13 in addition to the engine 11. The assist generator / motor 14 is electrically connected to an assist inverter 36 via a three-phase AC cable 35 described later.

  Reference numeral 15 denotes a turning generator / motor constituting a power source of the turning device 3. This turning power generator / motor 15 is composed of an electric motor attached to a substantially central portion of the bottom plate 6A of the turning frame 6, and has a gear (not shown) that meshes with the turning device 3 via a speed reduction mechanism 15A. Yes. The turning generator / motor 15 is configured to turn the upper turning body 4 on the lower traveling body 2 via the turning device 3 by rotationally driving the gears by feeding power from a power storage device 24 described later. On the other hand, the turning generator / motor 15 can store the regenerative energy generated when the turning operation is decelerated in the power storage device 24. The turning generator / motor 15 is electrically connected to the turning inverter 34 via a three-phase AC cable 35.

  Reference numeral 16 denotes a floor member provided near the left side, which is one side of the left and right directions on the revolving frame 6. The floor member 16 is supported such that its front end position can be tilted (tilted up and tilted down) to the front end position of the revolving frame 6 via a tilt support member 21 described later. On the other hand, the rear position of the floor member 16 is supported by the upper portion of the counterweight 8. As shown in FIGS. 4, 7, and 9, the floor member 16 is located on the front side and has a footrest portion 16A on which an operator puts his / her foot, and a rising portion 16B which rises upward from the rear portion of the footrest portion 16A. A driver seat mounting portion 16C extending rearward from the upper side of the rising portion 16B toward the upper side of the engine 11, a back plate portion 16D extending diagonally upward from the rear portion of the driver seat mounting portion 16C, and the back plate The mounting plate portion 16E extends from the upper side to the rear side of the portion 16D.

  Further, a lever / pedal mounting portion 16F is provided on the front side of the footrest portion 16A, and an operating lever / pedal 19 for traveling, which will be described later, is provided on the lever / pedal mounting portion 16F. On the lower surface side of the lever / pedal mounting portion 16F, a tilt support member 21, which will be described later, is mounted with an interval in the left and right directions. Thereby, the floor member 16 can tilt up or down on the rear side with the tilt support member 21 as the tilt center. In the state where the floor member 16 is tilted down, the rear mounting plate portion 16E can be bolted to the floor mounting bracket 9 of the counterweight 8.

  Reference numeral 17 denotes a driver seat (see FIG. 2) provided on a driver seat mounting portion 16C constituting the floor member 16, and the driver seat 17 is seated by an operator. On the left and right sides of the driver's seat 17, work operating levers 18 for operating the work device 5 and the like are disposed. Further, the lever / pedal mounting portion 16F of the floor member 16 in front of the driver's seat 17 is provided with an operation lever / pedal 19 for travel that is operated by manual operation or stepping operation when the lower traveling body 2 is traveled. ing.

  Reference numeral 20 denotes a cab box provided on the floor member 16, and the cab box 20 is formed as a box body with a lid that is long in the upward and downward directions. The lower portion of the cab box 20 is attached around the floor member 16. In addition, it can replace with the cab box 20 and can also apply the canopy provided with the roof part on the support | pillar.

  Here, the floor member 16, the driver's seat 17, the operation lever 18 for operation, the operation lever / pedal 19 for traveling, the cab box 20, and the like are configured as one unit mounted on the turning frame 6. As shown in FIG. 7, the cab unit has a hinge structure in which the lever / pedal mounting portion 16F of the floor member 16 has an axis extending in the left and right directions with respect to the front end of the revolving frame 6 as a rotation axis. The left and right tilt support members 21 are attached. As a result, the cab unit can tilt upward and downward on the rear side with the tilt support member 21 on the front side as a fulcrum.

  Reference numeral 22 denotes a hydraulic oil tank as an oil storage tank (see FIG. 10). The hydraulic oil tank 22 is located on the right side which is the other side in the left and right directions of the revolving frame 6, specifically on the front side of the heat exchanger 12. Located in the vicinity of the right side frame 6E. The hydraulic oil tank 22 stores hydraulic oil supplied to the hydraulic pump 13.

  Reference numeral 23 denotes a fuel tank as an oil storage tank provided on the revolving frame 6 in the vicinity of the left front side of the hydraulic oil tank 22. The fuel tank 23 stores fuel supplied to the engine 11.

  Here, the hydraulic oil tank 22 and the fuel tank 23 constituting the oil storage tank are arranged on the right side of the right vertical plate 6C of the revolving frame 6 to form a space between the floor member 16 (cab box 20). doing. In a space between the tanks 22 and 23 and the floor member 16, a power storage device 24 described later can be disposed on the power storage device mount 7.

  A power storage device 24 is provided on the revolving frame 6, and the power storage device 24 is disposed on the power storage device mounting base 7 in a space between the fuel tank 23 and the floor member 16 (cab box 20). Has been. The power storage device 24 supplies power to the turning generator / motor 15 and the assist generator / motor 14 and receives power (storage) from the turning generator / motor 15 and the assist generator / motor 14. For example, a lithium ion battery is used. In addition to the lithium ion battery, for example, an electric double layer capacitor can be used as the power storage device 24. When a capacitor is used for the power storage device 24, it is preferable that a chopper is connected to the output terminal of the power storage device 24 and the output terminal voltage of the power storage device 24 is held constant by the chopper.

  The power storage device 24 is formed in a vertically long rectangular parallelepiped shape that is flat in the left and right directions and extends upward and downward so as to fit in a narrow space between the fuel tank 23 and the cab box 20. As shown in FIG. 16, the power storage device 24 is electrically connected to a disconnect switch 25 and inverters 34 and 36 described later via a power supply cable 38. The lower part of the power storage device 24 is attached to the attachment surface portion 7 </ b> A of the power storage device mounting base 7, and the rear portion is attached to the front surface portion 10 </ b> B of the heat exchanger cover 10.

  Reference numeral 25 denotes a disconnect switch provided on the upper front side of the power storage device 24. The disconnect switch 25 is provided, for example, connected to the positive output terminal of the power storage device 24 and has an operation button 25A (see FIG. 4). The disconnect switch 25 normally connects between the power storage device 24 and each of the inverters 34 and 36, and shuts off between the power storage device 24 and each of the inverters 34 and 36 when the button 25A is operated. It is.

  Reference numeral 26 denotes an engine front space formed below the driver seat mounting portion 16C of the floor member 16 and between the engine 11 and the rising portion 16B of the floor member 16 (see FIG. 7). In the front space 26 of the engine, an inverter 34 for turning, an inverter 36 for assisting, and a contactor box 37 are arranged via an electric component mounting bracket 27 described later.

  An electrical component mounting bracket 27 is provided in the revolving frame 6 in the engine front space 26. The electrical component mounting bracket 27 is formed as a separate member from the floor member 16. As shown in FIGS. 11 to 13, the electric component mounting bracket 27 includes a main bracket 28, an upper mounting portion 29, a lower mounting portion 30, and a vibration isolation member 31 which will be described later.

  A main bracket 28 forms a main body portion of the electrical component mounting bracket 27. The main bracket 28 includes a vertical plate 28A that covers the front side of the engine 11, and a horizontal plate 28B that extends rearward from the top of the vertical plate 28A. The upper mounting allowance 28C extending upward from the rear portion of the horizontal plate 28B, the lower mounting allowance 28D extending from the lower portion of the vertical plate 28A to the front side, the vertical plate 28A, the horizontal plate 28B, and the mounting allowances 28C and 28D. And a right face plate 28E fixed to the right edge of the step.

  The vertical plate 28A is provided with a plurality of female screw holes (all not shown) for attaching the turning inverter 34, the assisting inverter 36, and the contactor box 37. The upper mounting allowance 28C is provided with a plurality of, for example, three through-holes 28F in the left and right directions, and the lower mounting allowance 28D is provided with a plurality of, for example, four through holes in the left and right directions. A hole 28G is provided.

  Reference numeral 29 denotes an upper mounting portion disposed at an upper position of the electrical component mounting bracket 27. The upper mounting portion 29 is formed as a substantially rectangular plate that is long in the left and right directions. Three bolt insertion holes 29 </ b> A are provided at the upper position of the upper mounting portion 29 corresponding to the female screw holes 9 </ b> C of the floor mounting bracket 9 constituting the counterweight 8. On the other hand, a plurality of vibration isolating members 31 to be described later are attached to the lower position of the upper attachment portion 29.

  Reference numeral 30 denotes a lower mounting portion disposed at a lower position of the electrical component mounting bracket 27. The lower mounting portion 30 is formed in an angle shape from the horizontal plate 30A and the vertical plate 30B. The vertical plate 30B is provided with a plurality of bolt insertion holes 30C corresponding to the screw holes 6J so as to be provided in the rear horizontal plate 6F of the revolving frame 6. On the other hand, a plurality of vibration isolation members 31 to be described later are attached to the horizontal plate 30A.

  Reference numeral 31 denotes a plurality of vibration isolation members provided on the lower portion of the upper attachment portion 29 and the horizontal plate 30A of the lower attachment portion 30, respectively. The plurality of vibration isolation members 31 are formed by, for example, fixing the threaded portion 31A to the tip of an elastic member such as rubber. Each vibration isolation member 31 is attached to the upper attachment portion 29 and the lower attachment portion 30 on the elastic member side.

  Here, the upper mounting portion 29 having the three anti-vibration members 31 attached to the lower side is provided in each through hole 28F provided with the male screw portion 31A of each anti-vibration member 31 in the upper mounting allowance 28C of the main bracket 28. The nut 32 is inserted into the male screw portion 31 </ b> A and attached to the upper side of the main bracket 28. On the other hand, the lower mounting portion 30 with the four vibration isolating members 31 mounted on the upper side inserts the male screw portion 31A of each vibration isolating member 31 into each through hole 28G provided in the lower mounting allowance 28D of the main bracket 28. The nut 32 is screwed onto the male thread portion 31A so that the male bracket portion 31A is attached to the lower side of the main bracket 28.

  As shown in FIG. 12, the electrical component mounting bracket 27 assembled in this way has the upper mounting portion 29 face the vertical plate portion 9B of the floor mounting bracket 9 constituting the counterweight 8 and is inserted into the bolt insertion hole 29A. By screwing the bolt 33 into the female screw hole 9 </ b> C of the floor mounting bracket 9, the upper part of the electric component mounting bracket 27 can be attached to the front part of the counterweight 8 in a vibration-proof state. On the other hand, by causing the vertical plate 30B of the lower mounting portion 30 to face the rear horizontal plate 6F of the revolving frame 6, the bolt 33 inserted through the bolt insertion hole 30C is screwed into the female screw hole 6J of the rear horizontal plate 6F, The lower part of the electric component mounting bracket 27 can be attached to the revolving frame 6 in a vibration-proof state.

  Reference numeral 34 denotes a turning inverter electrically connected to the generator / motor 15 for controlling the generator / motor 15 for turning. The turning inverter 34 is attached to the main bracket 28 of the electrical component mounting bracket 27, specifically, the right side position on the power storage device 24 side of the vertical plate 28 </ b> A of the main bracket 28. As a result, as shown in FIG. 10, the turning inverter 34 is immediately behind the turning generator / motor 15 arranged at the substantially center position of the turning frame 6, that is, compared to the assisting inverter 36. It is arranged at a position close to the generator / motor 15.

  The turning inverter 34 is configured by combining a plurality of switching elements (not shown) and the like. The turning inverter 34 converts the AC regenerative power generated by the turning power generation / motor 15 into DC power and supplies it to the power storage device 24 during regeneration of the turning power generation / motor 15. On the other hand, when the turning generator / motor 15 is driven to turn, the DC power from the power storage device 24 is converted into AC drive power and supplied to the turning generator / motor 15.

  The turning inverter 34 is connected to the turning generator / motor 15 using a three-phase AC cable 35. The turning inverter 34 and the turning generator / motor 15 are arranged at close positions so as to face each other in the front and rear directions. Thereby, the said three-phase alternating current cable 35 which connects both can also be formed short.

  Reference numeral 36 denotes an assist inverter electrically connected to the generator / motor 14 for controlling the assist generator / motor 14. The assist inverter 36 is mounted on the vertical plate 28A of the main bracket 28 in line with the left side of the turning inverter 34 (the side away from the power storage device 24). Thereby, the assist inverter 36 is disposed at a position closer to the assist generator / motor 14 disposed on the left side of the engine 11 than the turning inverter 34.

  The assist inverter 36 is configured by combining a plurality of switching elements (not shown) and the like, like the turning inverter 34. The assist inverter 36 converts AC generated power generated by the assist generator / motor 14 into DC power and supplies it to the power storage device 24 when the assist generator / motor 14 generates power. On the other hand, when the assist generator / motor 14 is driven, the assist inverter 36 converts the DC power from the power storage device 24 into AC drive power and supplies it to the assist generator / motor 14.

  The assist inverter 36 is connected to the assist generator / motor 14 using a three-phase AC cable 35 in the same manner as between the swing inverter 34 and the swing generator / motor 15 described above. Since the assist inverter 36 and the assist generator / motor 14 are arranged at close positions, the three-phase AC cable 35 that connects them can also be formed short.

  Reference numeral 37 denotes a contactor box provided between the turning inverter 34 and the assisting inverter 36 and the power storage device 24. The contactor box 37 is arranged at a left position farther from the power storage device 24 than the inverters 34 and 36. The contactor box 37 includes, for example, one main voltage transmission contactor, two inverter contactors corresponding to each of the inverters 34 and 36, a charging relay, and the like (both not shown). Among the contactors for each inverter, one of the contactors for inverter performs connection and disconnection between the turning inverter 34 and the power storage device 24. The other inverter contactor performs connection and disconnection between the assist inverter 36 and the power storage device 24. These contactors are switched between a connected state and a disconnected state in accordance with, for example, an operation of an ignition key (not shown) and the button 25A of the disconnect switch 25.

  Here, the inverter 34 for turning, the inverter 36 for assist, and the contactor box 37 are arranged side by side in the left and right directions on the electrical component mounting bracket 27 arranged in the front space 26 of the engine. In this case, the turning inverter 34 is arranged at a position closest to the power storage device 24 in a plan view, the assist inverter 36 is arranged side by side on the left side of the turning inverter 34, and the contactor box 37 is more than the inverters 34, 36. It is arranged at the left position away from the power storage device 24.

  Thus, by arranging the turning inverter 34, the assisting inverter 36, and the contactor box 37 in a desired order, the turning inverter 34 and the turning generator / motor 15 can be arranged at close positions. And the assisting power generator / motor 14 can be arranged in a close position. Thereby, the three-phase alternating current cable 35 which connects the inverters 34 and 36 and the generator / motor 15 and 14 can be formed short. In addition, the power supply cable 38 connecting the power storage device 24, the inverters 34 and 36, and the contactor box 37 can be formed short, and wiring work can be easily performed.

  Reference numeral 39 denotes an exterior cover provided on the right side of the floor member 16, and the exterior cover 39 covers the heat exchanger 12, the hydraulic oil tank 22, the fuel tank 23, and the like. The exterior cover 39 is located on the rear side and covers a rear cover 39A that covers the upper side of the heat exchanger 12, and is provided on the front side of the rear cover 39A so that it can be opened and closed, and a right front cover 39B that covers the hydraulic oil tank 22 and the fuel tank 23. And a partition cover 39C provided to face the side surface of the cab box 20 so as to cover the upper surface from the left surface of the fuel tank 23.

  Reference numeral 40 denotes a control valve provided on the revolving frame 6 (see FIGS. 10 and 16). The control valve 40 is formed by a plurality of hydraulic control valves that control the traveling motors 2E, 2F of the lower traveling body 2 and the cylinders 5D, 5E, 5F of the work device 5. The control valve 40 supplies the pressure oil supplied from the hydraulic pump 13 to the hydraulic actuator corresponding to this operation according to the operation of the operation lever 18 for work.

  The hybrid excavator 1 according to this embodiment has the above-described configuration. Next, the operation of the excavator 1 will be described.

  First, the operator gets on the floor member 16 and sits on the driver's seat 17. By operating the operating lever / pedal 19 for traveling in this state, pressure oil is supplied from the control valve 40 to the traveling motors 2E, 2F of the lower traveling body 2, and the left and right drive wheels 2B are driven. The hybrid excavator 1 can be moved forward or backward.

  On the other hand, an operator seated in the driver's seat 17 operates the operation lever 18 for work to turn the upper swing body 4 by the swing device 3 (the power generator / motor 15 for swing) or to lift the work device 5 up and down. Or excavation work of earth and sand.

  Here, the case where the hydraulic pump 13 is driven by the engine 11 and the assisting generator / motor 14 will be described with reference to FIGS. 14 and 15. Reference numeral 41 denotes a rated output characteristic line that is a rated output of the engine 11, and reference numeral 42 denotes a characteristic line (PQ diagram) of the hydraulic pump 13. This characteristic line 42 is a PQ characteristic of the hydraulic pump 13 when the engine 11 is driven within the rated output (rated output characteristic line 41 of the engine 11). Reference numeral 43 denotes a total output characteristic line when the rated output of the engine 11 is assisted by the output of the assisting generator / motor 14.

  When the lower traveling body 2 is traveled at a low speed (low speed travel area 44), or when normal work is performed using the turning device 3 and the working device 5 (normal work area 45), the hydraulic pump 13 is lightened. What is necessary is just to drive with load. Therefore, when these low-speed running area 44 and normal working area 45 are used, the force necessary to drive the hydraulic pump 13 can be provided only by the rated output of the engine 11.

  On the other hand, when the lower traveling body 2 is traveled at a high speed (high speed travel time region 46), the load on the hydraulic pump 13 becomes larger than the light load. May act on the engine 11 and cause an engine stall. As described above, when the high-speed traveling region 46 is used, it is necessary to supply power to the assisting generator / motor 14 from the power storage device 24 and drive the assisting generator / motor 14 to assist the engine 11. That is, the output in this case is shown as a total output characteristic line 43 obtained by adding the output of the assisting generator / motor 14 to the rated output characteristic line 41 of the engine 11. Thereby, the hydraulic pump 13 can be driven against a heavy load. The case where the load of the hydraulic pump 13 is increased is exemplified by the high-speed traveling region 46. However, the case where a hydraulic attachment is increased by adding a work attachment or the hydraulic actuator is increased in size and becomes a heavy load. Is included.

  Thus, according to the present embodiment, the turning inverter 34, the assisting inverter 36, and the contactor box 37 are located below the driver seat mounting portion 16C of the floor member 16 and on the engine 11 and the rising portion 16B of the floor member 16. Are disposed in a space 26 in front of the engine formed therebetween.

  Therefore, by using the engine front space 26 provided between the rising portion 16B of the floor member 16 and the engine 11, the upper swing body 4 has a swing inverter used when the hydraulic excavator 1 is hybridized. 34, an assisting inverter 36 and a contactor box 37 can be arranged.

  As a result, when an existing hydraulic excavator equipped with only an engine is used as a power source and this small hydraulic excavator is hybridized, by utilizing the space 26 in front of the engine, a turning inverter 34, an assist inverter 36 and the contactor box 37 can be easily mounted.

  Further, in the engine front space 26, the turning inverter 34, the assisting inverter 36, and the contactor box 37 are arranged side by side in the left and right directions. Thereby, in a state where the floor member 16 is tilted (tilted up) so as to lift the rear side, the front engine space 26 can be largely opened to the outside. Therefore, by utilizing the largely open engine space 26, workability when connecting the inverter 34 for turning, the inverter 36 for assisting, and the contactor box 37, and maintenance workability such as inspection and repair can be improved. it can.

  The revolving frame 6 is provided with an electrical component mounting bracket 27 that is located in the front space 26 of the engine and is made of a member different from the floor member 16. Accordingly, by attaching the turning inverter 34, the assisting inverter 36, and the contactor box 37 to the electric component mounting bracket 27, these electric components can be attached to the turning frame 6 as one electric component unit. As a result, the turning inverter 34, the assisting inverter 36, and the contactor box 37 can be easily provided in the engine front space 26 via the electrical component mounting bracket 27, and the assembly workability and the maintenance workability can be improved. it can.

  Here, the electrical component mounting bracket 27 is provided with a plurality of vibration isolation members 31 between the main bracket 28, the upper mounting portion 29, and the lower mounting portion 30. Therefore, the turning inverter 34, the assisting inverter 36, and the contactor box 37 attached to the main bracket 28 can be supported in a vibration-proof state. Thereby, durability of each inverter 34,36, the contactor in the contactor box 37, etc. can be improved.

  On the other hand, since the power storage device 24 is disposed between the floor member 16 and the fuel tank 23, the turning inverter disposed in the engine front space 26 between the engine 11 and the rising portion 16B of the floor member 16. 34, the assisting inverter 36, and the contactor box 37 can be disposed at positions close to each other. Thus, the power storage device 24 and the turning inverter 34, the assisting inverter 36, and the contactor box 37 can be easily connected using the power supply cable 38.

  In addition, the turning inverter 34 is arranged at a position closest to the power storage device 24 in plan view, the assist inverter 36 is arranged side by side on the left side of the turning inverter 34, and the contactor box 37 is charged more than the inverters 34, 36. The configuration is such that it is disposed at a left side position that is separated from the device 24. Therefore, the turning inverter 34 and the turning generator / motor 15 can be arranged in close positions facing each other in the front and rear directions, and the assist inverter 36 is also located near the assist generator / motor 14 arranged on the left side of the engine 11. Can be placed. Thereby, the length dimension of the three-phase alternating current cable 35 which connects the inverters 34 and 36 and the generator / motor 15 and 14 can be formed short. When the length dimension of the three-phase AC cable 35 is formed short, deterioration due to heat generation can be suppressed, and durability, reliability, and the like can be improved.

  In addition, since the power supply cable 38 connecting the power storage device 24 (disconnect switch 25), the inverters 34 and 36, and the contactor box 37 can be formed short, the wiring work of the cable 38 can be easily performed.

  Furthermore, the engine 11 has its output set to a value that covers the force required to drive the hydraulic pump 13 with a light load. That is, in the low-speed traveling region 44 and the normal working region 45, the hydraulic pump 13 can be driven only by the rated output of the engine 11 indicated by the rated output characteristic line 41. Therefore, a small engine (small displacement) having a small output can be used as the engine 11. Thereby, with respect to the exhaust gas regulation for purifying the exhaust gas discharged from the engine 11, the output of the engine 11 can be suppressed to a non-regulation target, and the burden due to the regulation can be reduced. As a result, the existing hydraulic excavator can be hybridized at a low cost. In addition, since the engine 11 having a small output is reduced in size as a whole, a space for arranging the devices can be secured around the engine 11, and the upper turning body is reduced as the engine 11 is reduced in size. 4 can also be reduced in size.

  On the other hand, in the high-speed traveling region 46 (at the time of heavy load), the hydraulic pump 13 cannot be driven only by the rated output of the engine 11. Therefore, by assisting the output of the assisting generator / motor 14 with the rated output of the engine 11 and adding the output to obtain the output characteristic indicated by the total output characteristic line 43, the hydraulic pump 13 having a large load pressure is driven. Can do.

  In the embodiment, the turning inverter 34, the assisting inverter 36, and the contactor box 37 are attached to the electric component mounting bracket 27 made of a member different from the floor member 16, and the electric component mounting bracket 27 is attached to the turning frame 6 and the counter. The case where it is set as the structure attached to the floor mounting bracket 9 of the weight 8 is illustrated. However, the present invention is not limited to this, and for example, the rear horizontal plate 6F of the revolving frame 6 located in the engine front space 26 is extended upward, and the rear horizontal plate 6F is connected to the turning inverter 34, the assist inverter 36, and the contactor box. It is good also as a structure which attaches 37.

  In the embodiment, the case where the power storage device 24 is positioned between the floor member 16 and the fuel tank 23 and disposed on the revolving frame 6 has been described as an example. However, the present invention is not limited to this, and for example, the power storage device may be arranged at another place such as the lower side of the floor member.

1 hybrid compact hydraulic excavators 2 undercarriage 3 turning device 4 upper structure 5 working device 5A boom 5B arm 5C bucket 5D boom cylinder (hydraulic actuator)
5E Arm cylinder (hydraulic actuator)
5F Bucket cylinder (hydraulic actuator)
6 Turning frame 7 Power storage device mounting base 8 Counterweight 9 Floor mounting bracket 11 Engine 13 Hydraulic pump 14 Assist generator / motor 15 Rotating generator / motor 16 Floor member 16A Foot rest 16B Rising part 16C Driver seat attaching part 22 Hydraulic oil Tank (oil storage tank)
23 Fuel tank (oil storage tank)
24 Power Storage Device 26 Engine Front Space 27 Electric Component Mounting Bracket 34 Turning Inverter 35 Three-Phase AC Cable 36 Assist Inverter 37 Contactor Box (Contactor)
38 Cable 41 Engine rated output characteristic line 42 Hydraulic pump characteristic line (PQ diagram)
43 Total output characteristic line 44 Low-speed running area 45 Normal work area 46 High-speed running area

Claims (6)

A self-propelled crawler-type lower traveling body and a crawler-type lower traveling body that is mounted on the lower traveling body so as to be capable of turning via a turning device that uses a power generator / motor for turning as a power source. An upper revolving body that fits within the vehicle width dimension, and a working device provided on the front side of the upper revolving body so as to be able to move up and down using a hydraulic actuator as a power source,
The upper swing body is
A swivel frame forming a support structure;
A counterweight attached to the rear end of the swivel frame to balance the weight with the working device;
An engine mounted on the front side of the counterweight and mounted horizontally in a left and right direction on the rear side of the revolving frame;
A hydraulic pump having an input shaft coaxial with an output shaft of the engine and driven by the engine;
An assist generator / motor connected to the output shaft of the engine and the input shaft of the hydraulic pump;
The swivel frame is supported at a front portion on one side in the left and right directions through a tilting support member so that it can be tilted up and tilted down , and rises upward from the footrest portion and the rear portion of the footrest portion. rising unit, the driver's seat mounting portion extending rearward toward the upper of the engine from the upper side of the rising portion, and extend to the rear of the operator's seat mounting portion, consists of the mounting plate portion attached to said counterweight Floor members;
An oil storage tank that is provided on the other side in the left and right directions of the swivel frame and stores fuel or hydraulic oil therein;
A power storage device that feeds electric power to the turning generator / motor and the assist generator / motor, and receives electric power from the turning generator / motor and the assist generator / motor;
A turning inverter provided connected to the generator / motor to control the turning generator / motor;
An assist inverter provided connected to the generator / motor to control the assist generator / motor;
In the hybrid small hydraulic excavator provided with the contactor that is provided between the turning inverter and the assisting inverter and the power storage device and performs connection and disconnection between the two,
The inverter for turning, the inverter for assist, and the contactor are formed below the driver seat mounting portion of the floor member and between the engine and the rising portion of the floor member, and tilt the floor member. It is configured to be placed in the space in front of the engine that is opened to the outside in the up state ,
The swivel frame is provided with an electrical component mounting bracket that is located in the space in front of the engine and is made of a member different from the floor member,
The hybrid small hydraulic excavator characterized in that the turning inverter, the assist inverter and the contactor are attached to the electric component mounting bracket . The turning inverter, assisted inverter and the contactors, hybrid compact hydraulic excavator according to claim 1 comprising a structure in which the left and Ru are arranged side by side in the right direction in the engine front space. Said power storage device, a hybrid type small hydraulic excavator according to claim 1 comprising as a position above Ru disposed on the pivoting frame structure between the floor member and the oil storage tank. It said power storage device is arranged on the revolving frame positioned between the floor member and the oil storage tank,
Construction the swing inverter and the assist inverter are arranged side by side in a position close to the power storage device in a plan view, the contactor, the Ru is disposed at a position spaced apart from the electric storage device than the inverters The hybrid compact hydraulic excavator according to claim 1 . The engine output covers the force required to drive the hydraulic pump with a light load. When the load on the hydraulic pump becomes larger than the light load, the assist generator / motor is added to the engine output. The hybrid compact hydraulic excavator according to claim 1, wherein the output is assisted. The output of the engine is set to a value necessary for driving the hydraulic pump during low-speed traveling or normal work. During high-speed traveling, the output of the assist generator / motor is set to the output of the engine. The hybrid compact hydraulic excavator according to claim 1, wherein the hydraulic pump is configured to assist and drive the hydraulic pump.

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