JP2013144504A - Wheel type construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost and space-saving wheel type construction machine, while saving energy, reducing exhaust gas, and reducing noise due to power recovery at deceleration.SOLUTION: A wheel type construction machine 19 includes: a hydraulic pump 40 to be driven by an engine 22 and/or a first electric motor 23; a hydraulic motor 13 to be driven by pressurized oil which is supplied from the hydraulic pump 40; a drive transmission device 15 for transmitting driving force of the hydraulic motor 13 to wheels 11a, 11b; and a power shaft for connecting the drive transmission device 15 and the hydraulic motor 13. The wheel type construction machine further includes: a second electric motor 14 connecting with the power shaft; an inverter 51 for driving the second electric motor 14; and a battery device 24 to be connected with the second electric motor 14.

Description

  The present invention relates to a wheel type construction machine, and more particularly to a wheel type construction machine in which a wheel type construction machine such as a wheel type excavator is hybridized.

  Conventionally, in a wheel-type construction machine such as a wheel excavator, the engine driving force is transmitted through the hydraulic circuit in the same manner as a hydraulic work circuit for excavation or the like. The hydraulic working device includes a hydraulic pump, and this hydraulic pump is also driven by an engine to discharge pressure oil. When the accelerator pedal is operated, the engine speed is controlled, and by controlling both the pump flow rate and the travel drive force, the drive force control of the travel device is performed while ensuring the pump flow rate in the hydraulic work device necessary for the work. Yes.

  On the other hand, in recent years, hybrid construction machines have been studied, and there are hybrid construction vehicles that can reduce engine load fluctuations, save energy, reduce exhaust gas, and reduce noise by hybridizing the drive source ( For example, see Patent Document 1).

JP 2005-133319 A

  In the above-described prior art, the wheel is driven by supplying electric power generated by the generator driven by the engine to the battery and the electric motor for driving. Since the engine power is converted into electricity and used for driving, the power transmission efficiency is improved as compared with the conventional hydraulic transmission system. In addition, since the braking energy can be recovered by the power generation effect of the electric motor for traveling during traveling deceleration, the energy saving efficiency is improved.

  By the way, in a construction machine having a large vehicle body weight and a large running resistance, a large amount of power is required for driving. In the above-described conventional technology, it is necessary to cover this power only with the electric motor for driving, but the power may be approximately equal to the rated output of the engine mounted in the conventional hydraulic transmission system.

  For this reason, providing such an electric motor has a problem that the manufacturing cost increases and the size of a vehicle body for securing a mounting space is increased.

  The present invention has been made based on the above-described matters, and its purpose is to provide a low-cost, space-saving wheel-type construction machine that enables energy saving, exhaust gas reduction, and noise reduction by recovering power during deceleration. To do.

  In order to achieve the above object, the first invention is a hydraulic pump driven by an engine and / or a first electric motor, a hydraulic motor driven by pressure oil supplied from the hydraulic pump, and the hydraulic pressure A wheel-type construction machine comprising: a drive transmission device that transmits drive power of a motor to a wheel; and a power shaft that couples the drive transmission device and the hydraulic motor; a second electric motor coupled to the power shaft; And an inverter that drives the second electric motor, and a power storage device connected to the second electric motor.

  The second invention is characterized in that, in the first invention, the output of the second electric motor is half or less of the rated output of the engine.

  Furthermore, the third invention is the first or second invention, comprising an upper swing body and a lower traveling body, a first electric motor for driving the hydraulic pump, and a third for driving the upper swing body. An electric motor, an inverter that drives the first electric motor and the third electric motor, and a power storage device are arranged on the upper swing body, the second electric motor is arranged on the lower traveling body, and the second electric motor slips. It is connected to the power storage device arranged on the upper swing body through a ring.

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the first electric motor for driving the hydraulic pump and the third revolving unit for driving the upper revolving unit have an upper revolving unit and a lower traveling unit. An electric motor and an inverter that drives the first electric motor and the third electric motor are disposed in the upper swing body, the second electric motor and the power storage device are disposed in the lower traveling body, and the first and The third electric motor is connected to the power storage device disposed in the lower traveling body via a slip ring.

  According to the present invention, the hydraulic motor having a large output size ratio and the small output electric motor mainly intended for energy recovery during braking are provided to be used together on the same rotating shaft as the driving drive actuator. As well as reducing the mounting space for the travel drive device including the manufacturing cost, the manufacturing cost can be reduced. As a result, it is possible to provide a low-cost, space-saving wheel-type construction machine while enabling energy saving, exhaust gas reduction, and noise reduction by power recovery during deceleration.

1 is a side view showing a hybrid wheel excavator provided with a first embodiment of a wheel-type construction machine of the present invention. 1 is a system configuration diagram of an electric / hydraulic device constituting a first embodiment of a wheel type construction machine of the present invention. It is a top view which shows the upper turning body of the hybrid type wheel shovel provided with 1st Embodiment of the wheel type construction machine of this invention. It is a top view which shows the lower traveling body of the hybrid type wheel excavator provided with 1st Embodiment of the wheel type construction machine of this invention. It is a side view which shows the hybrid type wheel shovel provided with 2nd Embodiment of the wheel type construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 2nd Embodiment of the wheel type construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 3rd Embodiment of the wheel type construction machine of this invention.

  Hereinafter, embodiments of the wheel type construction machine of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a hybrid wheel excavator provided with a first embodiment of the wheel-type construction machine of the present invention, and FIG. 2 is an electric / motor-constituting first embodiment of the wheel-type construction machine of the present invention. 1 is a system configuration diagram of a hydraulic device. In the first embodiment, the wheel type construction machine of the present invention is applied to a hybrid type wheel excavator.

  In FIG. 1, the hybrid wheel excavator 1 includes a lower traveling body 10, an upper revolving body 20 that is turnable on the upper portion of the lower traveling body 10, and a front work machine 30.

  The lower traveling body 10 includes a traveling front wheel 11a, a rear wheel 11b, a chassis frame 12, a traveling hydraulic motor 13 that drives and controls the front and rear wheels 11a and 11b, a traveling electric motor 14, a transmission 15, and the like. And a drive device 19 configured.

  The rotating shaft of the traveling hydraulic motor 13 and the rotating shaft of the traveling electric motor 14 are coupled to the transmission 15. Power is transmitted from the transmission 15 to a front axle 17a and a rear axle 17b connected to the front wheel 11a and the rear wheel 11b, respectively, by a propeller shaft 16 extending in the longitudinal direction of the vehicle body.

  Inside the chassis frame 12, a center joint 42 and a slip ring 50 to which pressure oil from a hydraulic pump 40 provided in the upper swing body 20 and electric power from the battery 24 are supplied are provided. The supplied pressure oil rotates the traveling hydraulic motor 13, and the supplied electric power rotates the traveling electric motor 14 via the inverter 51.

  The upper swing body 20 includes a swing frame 21, an engine 22 as a prime mover provided on the swing frame 21, an assist power generation motor 23 driven by the engine 22, a swing electric motor 25, an assist power generation motor 23, and The upper rotating body 20 (the turning frame 21) is driven to turn with respect to the lower traveling body 10 by the driving force of the turning electric motor 25. The battery 24 is electrically connected to the turning electric motor 25.

  A driver's cab 26 is disposed at the left front portion of the upper swing body 20, and a counterweight 27 is disposed at the rear portion of the upper swing body 20. Furthermore, an articulated front working machine 30 is disposed in front of the upper swing body 20 so as to be rotatable in the vertical direction. The front work machine 30 includes a boom 31, a boom cylinder 32 for driving the boom 31, an arm 33 that is rotatably supported near the tip of the boom 31, and an arm cylinder 34 for driving the arm 33. And a bucket 35 rotatably supported at the tip of the arm 33, a bucket cylinder 36 for driving the bucket 35, and the like.

  Further, a hydraulic system for driving hydraulic actuators such as the boom cylinder 32, the arc cylinder 34, and the bucket cylinder 36 described above is mounted on the swing frame 21 of the upper swing body 20. The hydraulic system includes a hydraulic pump 40 (FIG. 2) serving as a hydraulic source for generating hydraulic pressure, and a control valve 41 (FIG. 2) for driving and controlling each actuator. The hydraulic pump 40 includes the engine 22 and / or an assist generator motor. 23.

  Next, a system configuration of the electric / hydraulic device of the wheel excavator will be schematically described. As shown in FIG. 2, the rotating shaft of the engine 22 is connected to the rotating shafts of the assist power generation motor 23 and the hydraulic pump 40. The driving force of the engine 22 is transmitted to the assist generator motor 23 and the hydraulic pump 40. The pressure oil discharged from the hydraulic pump 40 is supplied to a boom cylinder 32, an arm cylinder 34, a bucket cylinder 36, and a traveling hydraulic motor via a control valve 41 that controls a flow rate and a direction according to a command from an operating device (not shown). 13 is supplied.

  The electric system includes the traveling electric motor 14, the assist power generation motor 23, the battery 24, the turning electric motor 25, the inverters 51, 52, 53, the slip ring 50, and the like.

  DC power from the battery 24 is boosted to a predetermined bus voltage by a chopper or the like (not shown), an inverter 51 for driving the traveling electric motor 14, an inverter 52 for driving the assist power generation motor 23, and a swing electric motor 25 is input to an inverter 53 for driving 25. The battery 24 is charged and discharged depending on the driving state (whether it is powering or regenerating) of the traveling electric motor 14, the assist power generation motor 23, and the turning electric motor 25.

  The traveling hydraulic motor 13 constituting the driving device 19 provided in the lower traveling body 10 receives the pressure oil introduced from the hydraulic pump 40 of the upper swing body 20 through the center joint 42 and generates a driving force. Further, the rotating shaft of the traveling electric motor 14 constituting the driving device 19 is coupled to the rotating shaft of the traveling hydraulic motor 13, and these driving forces are transmitted to the transmission 15, the propeller shaft 16, the front axle 17a, and the rear axle. It is transmitted to the front wheel 11a and the rear wheel 11b by the side axle 17b. The traveling electric motor 14 is electrically connected to the battery 24 via a slip ring 50 that transmits power between the upper swing body 20 and the lower traveling body 10 and an inverter 51 that drives the traveling electric motor 14. Yes.

  Here, the output of the traveling electric motor 14 is desirably a capacity that is necessary and sufficient for power recovery during traveling deceleration, and it is sufficient that the driving ability is ensured by using it together with the traveling hydraulic motor 13. For example, it is desirable that the output is less than half of the rated output of the engine 22. A construction machine with a large weight also requires a large amount of power to travel because of its large traveling resistance. This means that the recovered power during deceleration is also greatly lost due to running resistance. For this reason, even if a traveling electric motor 14 having a capacity capable of covering the traveling only for the purpose of improving the power transmission efficiency at the time of driving, it is considered that the expected effect cannot be obtained from the viewpoint of power recovery during deceleration. Because it is.

  Next, the arrangement of the devices constituting the wheel excavator will be schematically described. FIG. 3 is a top view showing an upper turning body of a hybrid wheel excavator provided with the first embodiment of the wheel-type construction machine of the present invention, and FIG. 4 is a first embodiment of the wheel-type construction machine of the present invention. It is a top view which shows the lower traveling body of the hybrid type wheel shovel provided with. 3 and 4, the same reference numerals as those shown in FIG. 1 and FIG. 2 are the same parts, and detailed description thereof is omitted.

  As shown in FIG. 3, a swing electric motor 25, a center joint 42, and a slip ring 50 are disposed at a substantially central portion of the swing frame 21 of the upper swing body 20. Behind the cab 26 and behind the swing electric motor 25, the engine 22, the assist power generation motor 23, and the hydraulic pump 40 are arranged in a horizontally long posture in such a manner that their respective rotation shafts are coupled in series. . A unit composed of the engine 22, the assist power generation motor 23, and the hydraulic pump 40 is referred to as a power unit 60.

  An inverter 52 for driving the battery 24 and the assist power generation motor 23 and an inverter 53 for driving the swing electric motor 25 are arranged behind the power unit 60. These are arranged in a gap provided in the counterweight 27 provided in the rear part of the upper swing body 20.

  In the lower traveling body 10, as shown in FIG. 4, a propeller shaft 16 is disposed in the axial direction at the center in the width direction of the chassis frame 12. A transmission 15 that is connected to the front and rear propeller shafts 16 is disposed at a substantially central portion in the axial direction of the propeller shaft 16. In the transmission 15, a drive shaft is provided in parallel to the propeller shaft 16 in the axial direction, and the rotation shafts of the traveling hydraulic motor 13 and the traveling electric motor 14 are connected to the drive shaft.

  The inverter 51 for driving the traveling electric motor 14 is disposed on the opposite side in the width direction of the portion of the traveling hydraulic motor 13 disposed on the chassis frame 12.

  In the present embodiment described above, the hybrid wheel excavator 1 is driven by the hydraulic transmission by the hydraulic pump 40 and the traveling hydraulic motor 13 and part of the power transmission by the electric power transmitted by the traveling electric motor 14. May be driven to travel. In the latter case, since electric energy transmission has better energy transmission efficiency than hydraulic transmission, driving efficiency is better than the former traveling. Further, by using the electric power stored in the battery 24, it is possible to temporarily drive the vehicle with a driving force exceeding the rated output of the engine 22.

  When the hybrid wheel excavator 1 travels and decelerates, the braking energy generated is recovered while applying a braking force by the power generation effect of the traveling electric motor 14. At this time, it is desirable to use a traveling hydraulic motor 13 and a brake together as the braking force. The generated electric power is stored in the battery 24, so that it can be used as electric power for the other swing electric motor 25 and the assist power generation motor 23. As a result, in the hybrid wheel excavator 1, energy saving can be achieved comprehensively.

  According to the first embodiment of the wheel-type construction machine of the present invention described above, the travel hydraulic motor 13 having a large output size ratio as the travel drive actuator and the small output mainly intended for energy recovery during braking. Since the traveling electric motor 15 is provided so as to be used together on the same rotating shaft, the mounting space of the driving device 19 including the electric motor can be reduced and the manufacturing cost can be suppressed. As a result, it is possible to provide a low-cost, space-saving wheel-type construction machine while enabling energy saving, exhaust gas reduction, and noise reduction by power recovery during deceleration.

  Further, according to the first embodiment of the wheel-type construction machine of the present invention described above, since the heavy battery 24 is accommodated inside the counterweight 27, the weight of the battery 24 that is originally deadweight is counted. It can be utilized as the weight of the weight 27. Thus, it is not necessary to provide a new space for mounting the battery 24, and the space can be saved.

  Hereinafter, a second embodiment of the wheel type construction machine of the present invention will be described with reference to the drawings. FIG. 5 is a side view showing a hybrid type wheel excavator provided with a second embodiment of the wheel type construction machine of the present invention, and FIG. 6 is an electric motor constituting the second embodiment of the wheel type construction machine of the present invention. 1 is a system configuration diagram of a hydraulic device. 5 and 6, the same reference numerals as those shown in FIG. 1 to FIG. 4 are the same parts, and detailed description thereof is omitted.

  Although the second embodiment of the wheel-type construction machine of the present invention shown in FIG. 5 is configured by a hydraulic pressure source and a work machine that are substantially the same as those of the first embodiment, the following configurations are different.

  The inverter 52 for driving the battery 24 and the assist generator motor 23 and the inverter 53 for driving the swing electric motor 25 in the first embodiment are located inside the counterweight 27 at the rear portion of the upper swing body 20. However, in the present embodiment, the battery 24 is disposed outside the chassis frame 12 on the lower traveling body 10 side in the width direction, and the inverters 52 and 53 are disposed behind the cab 26 and turn. It arrange | positions at the rear part of the electric motor 25. FIG.

  As shown in FIG. 6, an inverter 52 for driving the battery 24 disposed in the lower traveling body 10, an assist power generation motor 23 disposed in the upper swing body 20, and an inverter 53 for driving the swing electric motor 25, Are electrically connected via a slip ring 50.

According to the second embodiment of the wheel-type construction machine of the present invention described above, the same effect as that of the first embodiment described above can be obtained.
Further, according to the second embodiment of the wheel-type construction machine of the present invention described above, since the heavy battery 24 is arranged in the lower traveling body 10, the center of gravity of the hybrid wheel excavator 1 can be lowered. . As a result, the stability of the hybrid wheel excavator 1 is improved.

  Hereinafter, a third embodiment of the wheel type construction machine of the present invention will be described with reference to the drawings. FIG. 7 is a system configuration diagram of the electric / hydraulic equipment constituting the third embodiment of the wheel type construction machine of the present invention. In FIG. 7, the same reference numerals as those shown in FIG. 1 to FIG.

  Although the third embodiment of the wheel-type construction machine of the present invention shown in FIG. 7 is configured by a hydraulic pressure source or the like that is substantially the same as that of the first embodiment, the following configuration is different.

  In the third embodiment, the wheel type construction machine of the present invention is applied to the hybrid wheel loader 2. For this reason, the center joint 42, the slip ring 50, the swing electric motor 25, the inverter 53 for driving the swing electric motor 25, and the like in the first and second embodiments are omitted.

  The driving device 19 includes a traveling front wheel 11a, a rear wheel 11b, a chassis frame 12, a traveling hydraulic motor 13 that drives and controls the front and rear wheels 11a and 11b, a traveling electric motor 14, a transmission 15, and the like. Has been.

  According to the third embodiment of the wheel-type construction machine of the present invention described above, the same effect as that of the first embodiment described above can be obtained.

  In the embodiment of the present invention, the wheel excavator and the wheel loader have been described as examples. However, the present invention is not limited thereto. The present invention can be similarly applied to a wheel-type construction machine that is driven to travel by the traveling hydraulic motor 13.

  In the embodiment of the present invention, the construction machine including the battery 24 as the power storage device has been described. However, the present invention is not limited to this. For example, a capacitor may be used as the power storage device.

DESCRIPTION OF SYMBOLS 1 Hybrid type wheel excavator 2 Hybrid type wheel loader 10 Lower traveling body 11a Front wheel 11b Rear wheel 12 Chassis frame 13 Traveling hydraulic motor 14 Traveling electric motor 15 Transmission 16 Propeller shaft 17a Front axle 17b Rear axle 19 Drive device 20 Upper revolving structure 21 Revolving frame 22 Engine 23 Assist power generation motor 24 Battery (power storage device)
25 swing electric motor 26 cab 27 counterweight 30 front work machine 31 boom 32 boom cylinder 33 arm 34 arm cylinder 35 bucket 36 bucket cylinder 40 hydraulic pump 41 control valve 42 center joint 50 slip ring 51 inverter 52 inverter 53 inverter

Claims (4)

A hydraulic pump driven by an engine and / or a first electric motor;
A hydraulic motor driven by pressure oil supplied from the hydraulic pump;
A drive transmission device for transmitting the drive power of the hydraulic motor to the wheel;
A wheel-type construction machine comprising a power shaft that couples the drive transmission device and the hydraulic motor,
A second electric motor coupled to the power shaft;
An inverter for driving the second electric motor;
A wheel type construction machine comprising: a power storage device connected to the second electric motor. In the wheel type construction machine according to claim 1,
The wheel type construction machine, wherein the output of the second electric motor is less than half of the rated output of the engine. In the wheel type construction machine according to claim 1 or 2,
An upper swing body and a lower traveling body,
A first electric motor for driving the hydraulic pump, a third electric motor for driving the upper rotating body, an inverter for driving the first electric motor and the third electric motor, and a power storage device are disposed on the upper rotating body,
The second electric motor is disposed on the lower traveling body;
The wheel type construction machine, wherein the second electric motor is connected to the power storage device arranged on the upper swing body through a slip ring. In the wheel type construction machine according to claim 1 or 2,
An upper swing body and a lower traveling body,
A first electric motor for driving the hydraulic pump, a third electric motor for driving the upper rotating body, an inverter for driving the first electric motor and the third electric motor, are disposed on the upper rotating body;
The second electric motor and the power storage device are disposed on the lower traveling body,
The wheel-type construction machine, wherein the first and third electric motors are connected to the power storage device disposed in the lower traveling body via a slip ring.

Images