JP2014001581A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To warm up a battery quickly and efficiently.SOLUTION: A hybrid shovel turning drive system is configured to generate thermal energy to raise the temperature of cooling water flowing in the turning motor 4 so as to warm up the battery 3 with the cooling water, by driving a turning motor 4 in the state of stationarily holding the motor with a parking brake 8, under the condition of non-turning operation, when the temperature of a battery 3 is lower than a warm-up setup value, constituting a need to warm up, after an engine 1 is started.

Description

  The present invention relates to a hybrid or electric construction machine.

  The background art will be described using a hybrid excavator as an example.

  In a hybrid excavator, a generator motor is connected to an engine as a power source, and a capacitor is charged by the generator action of the generator motor. When appropriate, the generator motor is caused to act as a motor by the capacitor power to assist the engine. Composed.

  In this hybrid excavator, as a turning drive system for turning the upper turning body, an electric turning unit using a turning electric motor as a drive source instead of or in addition to a hydraulic turning unit using a turning hydraulic motor as a drive source is provided. Provided during turning drive (acceleration including start-up and steady operation after acceleration, also referred to as powering), the upper revolving body is driven to turn by the power of the generator motor or capacitor, and the turning motor is generated during turn deceleration. A device is known that operates as a machine to exert braking force and charges the regenerative power to a capacitor (see Patent Documents 1 and 2).

  In this hybrid excavator, the capacity of the condenser decreases at low temperatures, and the capacity of the condenser (discharge performance) declines and sufficient electric power cannot be obtained.Therefore, in the low temperature environment such as winter, the condenser is also heated to an appropriate temperature like the engine. It is desirable to take measures to warm up.

  As a countermeasure against this warm-up, as shown in Patent Document 2, when the temperature of the capacitor becomes lower than the set value, the generator motor is operated to force the capacitor to charge and discharge, and by internal heating A technique for increasing the temperature of the battery has been proposed.

  On the other hand, if the capacitor is continuously used in a high temperature state, the capacitor deteriorates quickly, so it is necessary to cool the capacitor so as not to exceed an appropriate temperature.

  In addition, since other hybrid devices such as a swing motor and a controller such as a motor for controlling the operation of the motor and the generator motor generate heat during use, it is necessary to cool them in order to maintain a certain performance.

  As a cooling technique of this storage device and a hybrid device that requires cooling (hereinafter, sometimes referred to collectively as a “required cooling device”), as shown in Patent Document 3, the storage device and the required cooling device are connected by a pipe line with a pump. A technology is known in which a device cooling device is connected and cooled by circulating a cooling medium such as water.

JP-A-2005-290882 JP 2010-127271 A W02008 / 015798

  In general, the internal resistance of the battery is set small from the viewpoint of improving system efficiency.

  For this reason, according to the known technique of Patent Document 2 in which internal heat generation due to the internal resistance of the battery is used for warming up, the heat generation amount of the battery is small and the warming-up efficiency is poor, and it takes a long time to warm up the battery.

  In addition, there is a problem that the life of the capacitor is shortened by making the forced charge / discharge time of the capacitor at a low temperature long.

  On the other hand, it is conceivable to use the cooling technique described in Patent Document 3 as a warming-up technique for the battery, that is, to warm up the battery with a cooling medium whose temperature has been raised by engine operation.

  However, the engine temperature alone takes time to increase the temperature of the medium, and it takes a long time to warm up the battery, similar to the technique of Patent Document 2.

  Therefore, the present invention provides a construction machine that can efficiently warm up a capacitor in a short time.

  As means for solving the above problems, in the present invention, an engine as a power source, a capacitor, a working device that operates on the drive side and the regeneration side, an electric motor that drives the working device, and a braking force applied to the electric motor A brake device that adds a cooling medium, a device cooling device that sends a cooling medium to a plurality of cooling devices including the capacitor and an electric motor to cool them, a capacitor temperature detecting unit that detects the temperature of the capacitor, and a control unit. The control means, after starting the engine, a command to operate the brake device at the time of warm-up required when the temperature of the battery is lower than a warm-up set value set in advance with reference to an appropriate temperature of the battery, A command for driving the electric motor is output, and the cooling medium temperature is increased by the heat generated by the electric motor so that the warming-up operation of the battery is performed. That.

  In this way, by driving the electric motor in a brake operating state, heat energy is generated, and the cooling medium temperature of the cooling device is raised by the heat energy from the engine operation and the electric motor heat energy, thereby warming up the capacitor. Since it was set as the structure, an electrical storage device can be warmed up efficiently.

  In particular, according to this configuration, since the motor is not simply operated with no load but is generated with a high load operation in a state of being restrained by a brake device, the warm-up efficiency is particularly good.

  For this reason, it becomes possible to raise the temperature of the battery to an appropriate temperature in a short time.

  In the present invention, it is desirable to include a generator motor driven by the engine, and the control means is configured to drive the motor only by the electric power generated by the generator motor when the engine needs to be warmed up. Item 2).

  According to this configuration, since the charging / discharging action of the capacitor at a low temperature is not performed, it is possible to suppress the deterioration of the capacitor and the shortening of the life due thereto.

  However, in the present invention, the capacitor may be used alone or in combination with a generator motor as a power source for driving the motor.

  Even in this case, since the warm-up of the capacitor can be completed in a short time as described above, the burden on the capacitor is reduced to the minimum, and the risk of shortening the life can be reduced.

  In the present invention, it is provided with a device temperature detecting means for detecting the temperature of a cooling-required device other than the capacitor, and the control means has at least one temperature of the plurality of cooling-required devices determined in advance for the cooling-required device. It is desirable that the warm-up operation is stopped when the warm-up stop set value is reached (claim 3).

  According to this configuration, it is possible to prevent deterioration or breakage due to an excessive temperature rise of a cooling-requiring device including a capacitor, which is a temperature monitoring target.

  In this case, the device whose temperature is to be monitored may be either one of the capacitor or the electric motor, or both. Alternatively, other cooling devices (for example, a controller such as a motor that controls a motor and a generator motor) may be targeted.

  In the present invention, operation detecting means for detecting that the work device has been operated is provided, and the control means executes the warm-up operation on the assumption that the work device is not operated, and the work device It is desirable that the warm-up operation is stopped when the is operated.

  According to this configuration, since the warm-up operation is performed only when the work device is not operated, in other words, the warm-up operation is not performed during the operation, and the warm-up is stopped if there is an operation even during the warm-up operation. Since normal operation is started, there is no possibility that workability is impaired.

  According to the present invention, the battery can be efficiently warmed up in a short time.

1 is a system configuration diagram according to an embodiment of the present invention. It is a flowchart for demonstrating the effect | action of embodiment.

  The embodiment is applied to a turning drive system of a hybrid excavator.

  FIG. 1 shows a system configuration of the embodiment.

Drive system As shown in the figure, a generator motor 2 that performs a generator action and a motor action is connected to the engine 1, the generator motor 2 is driven by the engine 1 to perform a generator action, and the generated electric power is sent to the capacitor 3. On the other hand, when appropriate, the generator motor 2 performs an electric motor action with the electric power of the capacitor 3 to assist the engine 1.

  Usually, a hydraulic pump (not shown) is connected to the generator motor 2 in parallel or in tandem with the engine 1, and the hydraulic actuator is driven through the control valve by the oil discharged from the hydraulic pump.

  Further, as other hybrid devices, there are provided a turning motor 4 as a turning drive source, a controller 5 such as an electric motor, and a control unit 6 as a control means, and the operation state of the turning operation lever 7 as a turning operation means, Based on the charging state and the like, the control unit 6 and the controller 5 such as the motor operate the generator motor 2, the swing motor 4, and the capacitor 3 (operation / stop of the generator motor 2 and the swing motor 4, charge / discharge of the capacitor 3, etc.) Is controlled.

  Here, the swing motor 4 is driven (powering drive) by the electric power generated by the generator motor 2 or the electric power of the capacitor 3, while performing a regenerative action at the time of deceleration, and the regenerative electric power charges the capacitor 3 or the generator motor 2. Or it is sent as driving power for engine assist.

  On the other hand, the swing motor 4 is provided with a parking brake 8 as a brake device that holds the motor 4 in a stopped state (applies a braking force in the stopped state).

  The parking brake 8 is configured, for example, as a negative brake that releases the brake when the hydraulic pressure is introduced and operates the brake when the hydraulic pressure is released, and the brake operation / release is controlled by a signal from the control unit 6.

  That is, basically, the brake is released when the turning operation lever 7 is operated, and the brake is activated when not operated.

Cooling system Three devices, ie, a motor controller 5, a turning motor 4, and a capacitor 3, which are devices that require cooling (cooling required devices), are connected in series by a cooling line 9, and the inlet side of this series circuit is the pump 10. The equipment cooling device 12 is configured by connecting the outlet side to the suction side of the pump 10 via the cooler 11 on the discharge side.

  A cooling medium (described in the case of water) is passed through the cooling pipe 9, and this cooling water circulates in the order of a pump 10-a controller such as an electric motor 5-a turning electric motor 4-a condenser-a cooler 11-a pump 10. Cool the tripartite or warm up to warm up as described below.

  The pump 10 is normally driven by the engine 1, but may be configured to be driven by a pump electric motor when the engine is started.

  Moreover, you may incorporate the generator motor 2 and the control unit 6 in this equipment cooling device 12 as needed.

  Further, as a detecting means, an operation sensor (for example, a potentiometer) 13 as a turning operation detecting means for detecting the presence / absence of an operation of the turning operation lever 7, and the temperatures t1, t2 of the controller 5 such as the electric motor 5, the turning electric motor 4, and the capacitor 3 are detected. , T3 detecting temperature sensors 14, 15 and 16, and operation state signals and temperature signals from these sensors 13 to 16 are sent to the control unit 6.

  The control unit 6 controls the warm-up operation and the stop thereof for raising the storage battery temperature at a low temperature based on each sensor signal.

  The operation of the control unit 6 will be described with reference to the flowchart of FIG.

  Control starts when the engine is started, and in step S1, it is determined whether or not the storage battery temperature t3 is lower than a warm-up set value Ta determined in advance based on the appropriate temperature of the storage battery 3.

  If YES (t3 ≦ warm-up set value Ta), it is determined that the battery 3 needs to be warmed up (when warming-up is required), the process proceeds to step S2, and it is determined whether or not the turning operation lever 7 is not operated.

  Here, the warm-up operation is started only in the case of YES (non-operation), and the parking brake 8 is brought into the brake operation state in step S3 (actually, the state is maintained because it is originally in the brake operation state).

  In the subsequent step S4, the generator motor 2 is operated, and the turning motor 4 is driven only by the electric power generated by the generator motor 2.

  Here, since the pump 10 of the equipment cooling device 12 is driven when the engine is started and the equipment cooling device 12 is in operation, the cooling water is heated and heated by the engine heat and the heat generated in the turning electric motor 4, The condenser 3 is heated by this cooling water.

  That is, the warm-up operation of the battery 3 is performed.

  In step S5, it is determined whether the temperature of any one of the controller 5 such as the electric motor controller 5, the turning electric motor 4, and the electric storage device 3 is equal to or higher than a warm-up stop set value Ts determined in advance for the device. When YES (t1 or t2 or t3 ≧ Ta), the operation of the generator motor 2 and the swing motor 4, that is, the warm-up operation is automatically stopped, and the process returns to step S1.

  If NO in step S1 (t3> warm-up set value Ta), it is assumed that the capacitor 3 does not need to be warmed up. If NO in step S2 (with lever operation), the warm-up operation is performed from the viewpoint of work priority. Since it should not enter, it returns to step S1 and continues monitoring.

  If NO in step S5 (the temperature of any of the three has not reached the warm-up stop set value), the warm-up operation should be continued and the process returns to step S1.

  Thus, by driving the turning electric motor 4 in the brake state, the electric energy is generated in the electric motor 4, and the cooling water temperature of the equipment cooling device 12 is increased by the thermal energy from the engine operation and the electric motor thermal energy, As a result, the capacitor 3 is warmed up, so that the capacitor 3 can be warmed up efficiently.

  In particular, according to this configuration, since the turning electric motor 4 is not simply operated with no load, but is heated by a high load operation in a state of being restrained by the parking brake 8, the warm-up efficiency is particularly good.

  For this reason, it becomes possible to heat up the battery 3 to an appropriate temperature in a short time.

  Moreover, since the turning electric motor 4 is driven only by the electric power generated by the generator motor 2 at the time of warming up, the charging / discharging action of the battery 3 at a low temperature is not performed. For this reason, deterioration of the battery 3 and the shortening of the lifetime due to this can be suppressed.

  Furthermore, in order to stop the warm-up operation when at least one temperature of the cooling-required equipment (the controller 5 such as the electric motor 5, the turning electric motor 4, and the battery 3) reaches a predetermined warm-up stop set value for the equipment. Therefore, it is possible to prevent deterioration and breakage due to excessive temperature rise of the device.

Other embodiments
(1) When warming up is required, the battery 3 may be used alone or in combination with the generator motor 2 as a power source for driving the swing motor 4.

  Even in this case, since warming up of the capacitor 3 can be completed in a short time as described above, the burden on the capacitor 3 can be minimized and the risk of shortening the life can be reduced.

  (2) In the above-described embodiment, the warm-up operation is stopped when the temperature of any one of the controller 5 such as the motor 5, the swing motor 4, and the capacitor 3 reaches the warm-up stop set value Ts. However, the target of temperature monitoring for the warm-up stop is either two or one of the above three from the viewpoint of a device that is highly necessary to avoid high temperature or a device that is prone to failure due to high temperature ( For example, it may be limited to the capacitor 3).

  (3) The present invention is suitable for the swing drive system of the hybrid excavator mentioned in the above embodiment, but can also be applied to a hybrid construction machine other than the shovel or a swing drive system of an electric excavator.

  Further, the present invention can be applied not only to the turning drive system but also to other drive systems using a motor with a brake, such as a crane winch drive system, in a hybrid or electric construction machine.

  Furthermore, the brake device is not limited to the one for holding the electric motor in a stopped state like the parking brake of the above-described embodiment, but may be one for both stopping and holding the electric motor.

  In addition, a brake device for warming up the electric motor may be newly provided.

DESCRIPTION OF SYMBOLS 1 Engine 2 Generator motor 3 Capacitor 4 Rotating motor 5 Motor controller etc. 6 Control unit as control means 7 Rotation operation lever as turning operation means 8 Parking brake as brake device 9 Cooling line 10 constituting cooling device Pump 11 Same as above, Cooler 12 Cooling device 14-16 Temperature sensor (temperature detection means)

Claims (4)

  An engine as a power source, a capacitor, a working device that operates on a driving side and a regeneration side, an electric motor that drives the working device, a brake device that applies a braking force to the electric motor, and a cooling medium that includes the electric storage device and the electric motor Including a device cooling device for cooling to a plurality of cooling devices including the above, a condenser temperature detecting means for detecting the temperature of the condenser, and a control means, the control means after the engine is started, When the warm-up is required, the temperature of the battery is lower than the warm-up set value determined in advance with respect to the appropriate temperature of the battery, a command for operating the brake device and a command for driving the motor are output. A construction machine configured to increase the temperature of the cooling medium by the generated heat so as to perform a warm-up operation of the battery.   The generator motor driven by the engine is provided, and the control means is configured to drive the motor only by electric power generated by the generator motor at the time of the warm-up required. Construction machinery.   Equipment temperature detecting means for detecting the temperature of the cooling equipment other than the condenser, wherein the control means is a warm-up stop setting in which at least one temperature of the plurality of cooling equipment is predetermined for the cooling equipment The construction machine according to claim 1 or 2, wherein the warm-up operation is stopped when a value is reached.   Operation detecting means for detecting that the work device has been operated is provided, and the control means performs the warm-up operation on the assumption that the work device is not operated, and when the work device is operated. The construction machine according to any one of claims 1 to 3, wherein the warm-up operation is stopped.

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