JP2017155721A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent any excessive load from being applied to drive a fan in respect to an engine under a situation in which abnormal state occurs at the engine.SOLUTION: A hydraulic shovel 1 comprises: an engine 12; a fan 17 operated under application of a driving force of the engine 12; a main control unit 20 for controlling a revolving speed of the fan 17; and an engine control unit 19 for limiting an output of the engine 12 rather than an output of the engine 12 kept at a normal state when an abnormal state occurs at the engine 12. The main control unit 20 obtains information for specifying a horse power rate indicating a present rate of output of the engine 12 in respect to the output of the engine 12 kept under the normal state from the engine control unit 19 and further limits the revolving speed of the fan 17 in such a manner that the revolving speed of the fan 17 is smaller as the horse power rate is lower, when the horse power rate is less than a pre-set horse power rate threshold in order to confirm that the abnormal state occurs at the engine 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a construction machine including an engine and a fan that operates using power of the engine.

  For example, the work machine described in Patent Document 1 is connected to an engine, a hydraulic pump connected to the output shaft of the engine, a fan motor driven by hydraulic oil discharged from the hydraulic pump, and an output shaft of the fan motor. And an air cooling fan.

  The work machine described in Patent Literature 1 includes an engine output mode switching switch for switching the engine output mode, and a controller that limits the output of the engine according to the switching state of the engine output mode switching switch. Yes.

  The engine output mode changeover switch is for selecting one of a P mode that does not limit the output of the engine and an E mode that limits the output of the engine at a light load to reduce fuel consumption. The controller limits the engine output relative to the engine output in the P mode when the E mode is selected.

  Here, when the engine output mode is set to the E mode, the engine output is limited, so the heat generation amount in the engine is small.

  Therefore, when the engine output mode is set to the E mode, the controller adjusts the rotational speed so as to lower the rotational speed of the air cooling fan as compared to the case where the P mode is set.

Japanese Patent No. 5518589

  In the work machine described in Patent Document 1, when the E mode is selected by the engine output mode switching switch and the output of the engine is limited, the rotation speed of the air cooling fan decreases.

  On the other hand, even when an abnormality occurs in the engine (for example, when a failure of a sensor [a water temperature sensor that detects the temperature of cooling water, etc.] occurs), the output of the engine is limited.

  However, the work machine described in Patent Document 1 reduces the rotation speed of the air cooling fan when the engine output mode is set to the E mode. Even if an abnormality occurs, the rotation speed of the air cooling fan is maintained. In this case, there is a possibility that an excessive load is applied to the engine whose output is limited due to the occurrence of abnormality by driving the air cooling fan.

  An object of the present invention is to prevent an excessive load from being applied to an engine by driving a fan in a situation where an abnormality occurs in the engine.

  In order to solve the above problems, the present invention provides a construction machine, an engine, a fan that operates using power of the engine, a fan controller that controls the rotational speed of the fan, and an abnormality in the engine. An engine controller that limits the output of the engine that is in a normal state when the engine occurs, and the fan controller is configured to output the engine with respect to the engine output in a normal state. Information for specifying a horsepower factor indicating a current output ratio is acquired from the engine controller, and the horsepower factor is set in advance to confirm that the engine has an abnormality. Provided is a construction machine that limits the rotational speed of the fan so that the rotational speed of the fan becomes smaller as the horsepower factor becomes smaller when the power is below a threshold value.

  According to the present invention, it is possible to confirm that an abnormality has occurred in the engine when the horsepower factor is equal to or less than the horsepower factor threshold value. That is, the “horsepower factor threshold” in the present invention is set in advance based on the ratio of the output limited by the engine controller when an abnormality occurs in the engine.

  Furthermore, in the present invention, when the engine is abnormal, the fan speed is limited so that the smaller the horsepower factor is, the smaller the fan speed is. Therefore, the greater the engine output limit, The applied load can be reduced.

  Therefore, according to the present invention, it is possible to prevent an excessive load from being applied to the engine by driving the fan in a situation where an abnormality has occurred in the engine.

  Here, the fan controller may acquire the horsepower factor itself as “information for specifying the horsepower factor” from the engine control unit, but if the horsepower factor does not contribute to the engine control, It is necessary to add an extra function (a function for calculating a horsepower factor) to the control unit, which is inefficient.

  Therefore, in the construction machine, the fan controller stores in advance normal output information regarding the output of the engine in a normal state, and acquires current output information regarding the current output of the engine from the engine controller, Furthermore, it is preferable to calculate the horsepower factor based on the normal output information and the current output information.

  According to this aspect, it is possible to efficiently specify the horsepower factor by adding a function of calculating the horsepower factor to the fan controller that controls the fan without adding an extra function to the engine controller. it can.

  Here, the rotational speed of the fan may be limited when the horsepower factor is equal to or less than the horsepower reduction threshold even in a situation where the temperature of the object to be cooled by the fan is relatively high. However, in this case, it is possible to prevent the engine from being overloaded, but there is a possibility that a new problem may occur due to the temperature rise of the object to be cooled.

  Therefore, the construction machine further includes a temperature detector that detects the temperature of the object to be cooled that is cooled by the fan, and the fan controller has the horsepower factor equal to or less than the horsepower reduction threshold and the temperature. When the temperature of the object to be cooled detected by the detector exceeds a preset temperature threshold value, it is preferable to restrict the rotational speed of the fan.

  According to this aspect, even when the horsepower factor is equal to or less than the horsepower factor threshold, it is possible to prohibit the restriction on the rotational speed of the fan when the temperature of the object to be cooled exceeds the temperature threshold. Therefore, it is possible to prevent a new problem from occurring due to the temperature rise of the object to be cooled.

  The fan controller, for example, sets the target rotation speed of the fan based on the temperature of the object to be cooled, and stores in advance a characteristic indicating the relationship between the magnitude of the horsepower factor and the limiting ratio of the target rotation speed. The engine output may be limited based on the horsepower factor. However, in this case, it is necessary to prepare a characteristic indicating the relationship between the horsepower factor and the limiting rate and to secure an area for storing this characteristic.

  Therefore, the construction machine further includes at least one temperature detector that detects the temperature of the object to be cooled that is cooled by the fan, and the fan controller detects the temperature of the object to be cooled that is detected by the temperature detector. A target rotational speed of the fan is set based on temperature, and the target rotational speed of the fan is limited by multiplying the target rotational speed by the horsepower factor when the horsepower factor is equal to or less than the horsepower factor threshold value. It is preferable.

  According to this aspect, since the target rotational speed can be limited based on the target rotational speed and the horsepower factor set based on the temperature of the object to be cooled, a separate characteristic is prepared and the characteristic is stored. It becomes unnecessary to secure the area.

  The construction machine includes a plurality of the temperature detectors, and the fan controller sets a target rotation speed of the fan based on the temperature detected by each temperature detector, and sets all the target rotation speeds. It is preferable to limit the target rotational speed of the fan by selecting the largest one from the above and multiplying the selected target rotational speed by the horsepower factor.

  According to this aspect, the target rotational speed is set for each temperature detected by the plurality of temperature detectors, and the largest one of these target rotational speeds is selected. As a result, it is possible to reduce the load on the engine while ensuring the cooling capacity of the fan based on the highest temperature.

  In the above aspect, the plurality of temperature detectors may detect the temperature of a common object to be detected, or may detect the temperature of another object to be detected. The construction machine is connected to the engine and has a function of changing tilt, a hydraulic motor that is operated by hydraulic oil supplied from the hydraulic pump and has a rotating shaft connected to the fan, Preferably, the fan controller outputs a command for reducing the tilt of the hydraulic pump when the horsepower factor is equal to or less than the horsepower factor threshold value.

  According to this aspect, since an existing hydraulic device (such as a hydraulic oil tank) can be used when a hydraulically driven construction machine is used as an application target, the construction machine can be configured compactly.

  On the other hand, the construction machine is connected to the engine and generates electric power using the power of the engine, and an electric motor that operates by the electric power generated by the generator and has a rotating shaft connected to the fan; An inverter that controls electric power supplied from the generator to the electric motor, and the fan controller is supplied from the generator to the electric motor when the horsepower factor is equal to or less than the horsepower factor threshold value. A command for limiting power may be output to the inverter.

  According to this aspect, when a hybrid construction machine is used as an application target, an existing hybrid device (such as a generator motor) can be used, so that the construction machine can be configured compactly.

  Further, since the rotational speed of the fan is electrically controlled, the rotational speed of the fan can be controlled more accurately than in the case where the rotational speed of the fan is hydraulically controlled.

  According to the present invention, it is possible to prevent an excessive load from being applied to drive the fan to the engine in a situation where an abnormality has occurred in the engine.

1 is a side view showing an overall configuration of a hydraulic excavator according to a first embodiment of the present invention. It is a circuit diagram which shows a part of drive system provided in the hydraulic shovel of FIG. It is a graph which shows a normal torque map and a limitation torque map. It is a map which shows the relationship between the hydraulic oil temperature memorize | stored in the main controller of FIG. 2, and a fan rotation speed. It is a map which shows the relationship between the engine water temperature memorize | stored in the main controller of FIG. 2, and a fan rotation speed. It is a flowchart which shows the process performed by the main controller of FIG. It is a circuit diagram which shows a part of drive system provided in the hybrid shovel which concerns on 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The following embodiments are examples embodying the present invention, and are not of a nature that limits the technical scope of the present invention.

<First Embodiment>
Referring to FIG. 1, a hydraulic excavator 1 according to a first embodiment of the present invention includes a lower traveling body 2 having a crawler 2a, an upper revolving body 3 provided on the lower traveling body 2 so as to be able to swivel, and an upper portion. And an attachment 4 attached to the swivel body 3.

  The attachment 4 includes a boom 5 having a base end portion rotatably attached to the upper swing body 3, an arm 6 having a base end portion rotatably attached to the distal end portion of the boom 5, and an arm And a bucket 7 that is rotatably attached to the tip of 6.

  The attachment 4 further includes a boom cylinder 8 that rotates the boom 5 relative to the upper swing body 3, an arm cylinder 9 that rotates the arm 6 relative to the boom 5, and a bucket 7 that rotates relative to the arm 6. And a bucket cylinder 10 that performs.

  The excavator 1 includes a drive system 11 for driving the excavator 1 as shown in FIG.

  The drive system 11 is connected to an engine 12, a main pump 13 connected to the output shaft of the engine 12, a hydraulic drive circuit 14 to which hydraulic oil discharged from the main pump 13 is supplied, and an output shaft of the engine 12. A fan pump (hydraulic pump) 15, a fan motor (hydraulic motor) 16 to which hydraulic oil discharged from the fan pump 15 is supplied, a fan 17 connected to the fan motor 16, and the fan 17. A heat exchanger 18 for exchanging heat with the supplied cooling air.

  The main pump 13 is a so-called variable displacement hydraulic pump having a function of changing its tilt.

  Although not shown, the hydraulic drive circuit 14 includes a hydraulic actuator and a control valve that controls supply and discharge of hydraulic oil from the main pump 13 to the hydraulic actuator. The hydraulic actuator includes the above-described cylinders 8 to 10, a turning motor (not shown) that drives the upper turning body 3 to turn, and a traveling motor (not shown) provided on the lower traveling body 2.

  The fan pump 15 is a so-called variable displacement hydraulic pump having a function of changing its tilt.

  The fan motor 16 has a rotating shaft (not shown) that is operated by hydraulic oil supplied from the fan pump 15 and connected to the fan 17.

  The fan 17 operates using the power of the engine 12. Specifically, the fan 17 operates as the fan motor 16 is operated by the hydraulic oil supplied from the fan pump 15 using the power of the engine 12 as described above.

  The heat exchanger 18 includes a radiator 18a for cooling the cooling water that cools the engine 12, and an oil cooler 18b for cooling the working oil.

  Further, the drive system 11 is electrically connected to the engine controller 19 that controls the drive of the engine 12 and the engine controller 19, and the main controller (fan controller) that controls the drive of the hydraulic drive circuit 14 and the fan 17. 20).

  The engine controller 19 is electrically connected to the engine 12, monitors the state of the engine 12, and controls driving of the engine 12 according to the state of the engine 12.

  Specifically, the engine controller 19 controls the output torque of the engine 12 according to a normal torque map M1 indicated by a solid line in FIG. 3 when the engine 12 is in a normal state. The normal torque map M1 shows the relationship between the rotational speed of the engine 12 and the output torque in a normal state. The normal torque map M1 is stored in the engine controller 19 in advance.

  On the other hand, the engine controller 19 determines whether the engine 12 is in a normal state when an abnormality occurs in the engine 12 (for example, when a failure of a sensor [a water temperature sensor that detects the temperature of cooling water, etc.] occurs). The output of the engine 12 is limited rather than the output. Specifically, the engine controller 19 controls the output torque of the engine 12 according to a limit torque map M2 indicated by a broken line in FIG. 3 when an abnormality occurs in the engine 12. The limit torque map M2 shows the relationship between the rotational speed of the engine 12 in which an abnormality has occurred and the output torque, and the output torque lower than the normal torque map M1 except for the portion where the output torque of the engine 12 is zero. Is set in the range. The limit torque map M2 may be stored in the engine controller 19 in advance, or may be created by the engine controller 19 according to the degree of abnormality of the engine 12.

  Referring to FIG. 2, the main controller 20 controls the drive of the hydraulic drive circuit 14 by adjusting the tilt of the main pump 13 that supplies hydraulic oil to the hydraulic drive circuit 14. Specifically, the drive system 11 includes a regulator 13a for adjusting the tilt of the main pump 13, a pilot pump 24 for supplying hydraulic oil to the regulator 13a, and an operation from the pilot pump 24 to the regulator 13a. And an electromagnetic proportional valve 22 for controlling the supply of oil.

  The main controller 20 controls the rotational speed of the fan 17 by adjusting the tilt of the fan pump 15 that supplies hydraulic oil to the fan motor 16. Specifically, the drive system 11 includes a regulator 15a for adjusting the tilt of the fan pump 15 and an electromagnetic proportional valve 23 for controlling the supply of hydraulic oil from the pilot pump 24 to the regulator 15a.

  Since the regulators 13a and 15a have the same configuration and the electromagnetic proportional valves 22 and 23 have the same configuration, the regulator 15a and the electromagnetic proportional valve 23 will be described below.

  The electromagnetic proportional valve 23 is energized to a position where the pilot pump 24 shuts off the regulator 15a (right side position in FIG. 2) in a state where the command is not received from the main controller 20, and the command is received from the main controller 20. The position is switched to a position for supplying hydraulic oil from the pilot pump 24 to the regulator 15a (left side position in FIG. 2). Further, the electromagnetic proportional valve 23 can adjust the flow rate of the hydraulic oil to the regulator 15a according to the magnitude of the command value (current value) from the main controller 20.

  The regulator 15a is urged so that the rod is contracted in a state where the hydraulic oil is not supplied from the pilot pump 24, and has a cylinder in which the rod extends when the hydraulic oil is supplied from the pilot pump 24.

  Therefore, in a state where no electrical command is input from the main controller 20 to the solenoid of the electromagnetic proportional valve 23, the cylinder rod of the regulator 15a is reduced and the tilt of the fan pump 15 is minimized. On the other hand, when an electric command is input from the main controller 20 to the solenoid of the electromagnetic proportional valve 23, the cylinder rod of the regulator 15a extends and the tilt of the fan pump 15 increases.

  Moreover, the main controller 20 sets the target rotation speed of the fan 17 based on the temperature of the cooling water cooled by the fan 17 and the hydraulic oil (each example of an object to be cooled). Specifically, the drive system 11 is provided in the engine 12, a water temperature sensor (temperature detector) 12 a that detects the temperature of the cooling water, a hydraulic oil tank 21 that stores hydraulic oil, and the hydraulic oil tank 21. And a hydraulic oil temperature sensor (temperature detector) 21a for detecting the temperature of the hydraulic oil. The water temperature sensor 12 a is electrically connected to the engine controller 19, and the main controller 20 acquires the temperature of the cooling water detected by the water temperature sensor 12 a via the engine controller 19. The hydraulic oil temperature sensor 21 a is electrically connected to the main controller 20. In FIG. 2, a plurality of hydraulic oil tanks 21 are shown for convenience of drawing, but in reality, the hydraulic excavator 1 is provided with one hydraulic oil tank.

  The main controller 20 stores the map of FIG. 4 showing the relationship between the temperature of the hydraulic oil and the rotational speed of the fan 17, and the temperature of the hydraulic oil detected by the hydraulic oil temperature sensor 21a and the map of FIG. Based on the above, the target rotational speed is specified.

  Further, the main controller 20 stores the map shown in FIG. 5 showing the relationship between the temperature of the cooling water and the rotation speed of the fan 17, and the temperature of the cooling water detected by the water temperature sensor 12a and the temperature shown in FIG. The target rotational speed is specified based on the map.

  Then, the main controller 20 sets a larger one of the target rotational speed based on the hydraulic oil temperature and the target rotational speed based on the coolant temperature as the target rotational speed.

  Further, the main controller 20 stores in advance a normal torque map (normal output information: see FIG. 3) M1 related to the output of the engine 12 in a normal state, and the current related to the current output of the engine 12 from the engine controller 19. Get output information. Here, the current output information is a normal torque map M1 when the engine 12 is in a normal state at the current time, and a limit torque map M2 when an abnormality occurs in the engine 12 at the current time.

  Then, the main controller 20 calculates a horsepower factor indicating the ratio of the current output of the engine 12 to the output of the engine 12 in a normal state based on the normal output information (normal torque map) and the current output information.

  Specifically, when the current output information is the limit torque map M2 and the rotation speed of the engine 12 is N, the main controller 20 outputs the output torque α1 and the limit torque map at the current rotation speed N in the normal torque map M1. The following equation (1) is calculated using the output torque α2 at the current rotational speed N of M2.

Horsepower factor at rotation speed N = (α2 / α1) × 100 (1)
Then, the main controller 20 rotates the fan 17 so that the lower the horsepower factor is, the smaller the number of revolutions of the fan 17 is when the horsepower factor obtained by the equation (1) is equal to or less than a preset horsepower factor threshold. Limit the number. Here, the “horse reduction threshold” is preliminarily determined based on the ratio of the output limited by the engine controller 19 when an abnormality occurs in the engine 12 in order to confirm that an abnormality has occurred in the engine 12. It is set. Specifically, when the ratio of the output of the engine 12 limited by the engine controller 19 differs depending on the degree of abnormality of the engine 12, the horsepower reduction threshold value is the one with the maximum ratio of the output limited by the engine controller 19. It is set as a standard. In this embodiment, the “horse reduction threshold” is set to 95%.

  In the present embodiment, the main controller 20 limits the rotation speed of the fan 17 so that the lower the horsepower factor, the smaller the rotation speed of the fan 17 by multiplying the target rotation speed of the fan 17 by the horsepower factor. To do. Specifically, the main controller 20 outputs a command for reducing the tilt of the fan pump 15 (outputs a smaller electric command value than when the engine 12 is normal).

  On the other hand, when the temperature of the cooling water and the temperature of the hydraulic oil detected by the water temperature sensor 12a and the hydraulic oil temperature sensor 21a shown in FIG. Even if it is below the horsepower factor threshold value, the limitation on the rotational speed of the fan 17 is prohibited.

  Specifically, a hydraulic oil temperature threshold is set for the hydraulic oil temperature. The hydraulic oil temperature threshold is a temperature at which a malfunction may occur in the hydraulic equipment (pumps 13 and 15, fan motor 16, and hydraulic oil tank 21) when the hydraulic oil temperature is maintained above the hydraulic oil temperature threshold. It is a preset temperature (for example, 95 ° C.).

  Further, a water temperature threshold is set for the temperature of the cooling water. The water temperature threshold is a temperature (for example, 100 ° C.) set in advance as a temperature at which the engine 12 may fail due to insufficient cooling of the engine 12 when the temperature of the cooling water exceeds the water temperature threshold. It is.

  Hereinafter, processing executed by the main controller 20 will be described with reference to FIGS. 2 and 6. FIG. 6 is a flowchart showing processing executed by the main controller 20.

  When the processing is started, first, the temperature of the hydraulic oil detected by the hydraulic oil temperature sensor 21a is acquired (step S1), and the fan for the oil cooler 18b is obtained based on the temperature of the hydraulic oil and the map of FIG. A target rotational speed of 17 is specified (step S2).

  Next, the temperature of the cooling water detected by the water temperature sensor 12a is acquired via the engine controller 19 (step S3), and the target rotation of the fan 17 with respect to the radiator 18a based on the temperature of this cooling water and the map of FIG. The number is specified (step S4).

  Then, the target rotational speed is determined by performing a high-order selection between the target rotational speed of the fan 17 for the oil cooler 18b and the target rotational speed of the fan 17 for the radiator 18a (step S5).

  Next, a current torque map is acquired from the engine controller 19 (step S6). Specifically, when the engine 12 is in a normal state at the current time, the main controller 20 acquires the normal torque map M1 of FIG. 3, while when the engine 12 is abnormal at the current time, the main controller 20 Obtains the limit torque map M2 of FIG.

  The horsepower factor is calculated by performing the calculation of the equation (1) using the torque map acquired in step S6 and the normal torque map M1 stored in the main controller 20 in advance (step S7).

  When the engine 12 is in a normal state, the values of α1 and α2 in the equation (1) coincide with each other so that the horsepower factor becomes 100%. On the other hand, when the engine 12 has an abnormality, the α2 in the equation (1) Since the value is smaller than the value of α1, the horsepower factor is less than 100%.

  Next, it is determined whether or not the horsepower factor is greater than a horsepower factor threshold value (step S8). The horsepower factor threshold value is set in advance with reference to the ratio of the output limited by the engine controller 19 when an abnormality occurs in the engine 12 in order to confirm that an abnormality has occurred in the engine 12.

  If it is determined that the horsepower factor is equal to or less than the horsepower factor threshold value (NO in step S8), it is determined whether or not the temperature of the hydraulic oil detected by the hydraulic oil temperature sensor 21a is greater than a preset hydraulic oil temperature threshold value. Determination is made (step S9).

  If it is determined that the temperature of the hydraulic oil is equal to or lower than the hydraulic oil temperature threshold (NO in step S9), it is determined whether or not the temperature of the cooling water detected by the water temperature sensor 12a is greater than a preset water temperature threshold. (Step S10).

  If it is determined that the temperature of the cooling water is equal to or lower than the water temperature threshold (NO in step S10), the target rotational speed is corrected to limit the rotational speed of the fan 17 (step S11). Specifically, in step S11, the rotational speed of the fan 17 is limited by multiplying the target rotational speed determined in step S5 by the horsepower factor calculated in step S7.

  After step S11, in step S12, a command value corresponding to the target rotational speed corrected as described above is output to the electromagnetic proportional valve 23.

  As a result, the engine 12 is abnormal, that is, the horsepower factor is equal to or lower than the horsepower factor threshold value (NO in step S8), and the hydraulic oil temperature and the cooling water temperature are the hydraulic excavator 1. In a situation where the temperature is low enough not to cause an abnormality (No in steps S9 and S10), the rotation speed of the fan 17 can be limited. Therefore, it is possible to prevent an excessive load for driving the fan from being applied to the engine 12 in a situation where an abnormality occurs in the engine 12.

  On the other hand, if it is determined as NO in step S8, that is, if it is determined that the engine 12 is in a normal state, in step S12, a command corresponding to the target rotational speed determined in step S5 is output. That is, since the engine 12 is in a normal state, the rotational speed of the fan 17 is not limited.

Further, when it is determined NO in step S9, that is, when it is determined that the temperature of the hydraulic oil is a temperature that may cause an abnormality in the hydraulic equipment, in step S12, the target rotational speed determined in step S5. A command corresponding to is output. Thus, the hydraulic equipment can be protected by preferentially performing cooling of the oil cooler 18b over the load reduction of the engine 12. Furthermore, if NO is determined in step S10, that is, the temperature of the cooling water. Is determined to be a temperature that may cause an abnormality in the engine 12, a command corresponding to the target rotational speed determined in step S5 is output in step S12. As described above, the cooling of the radiator 18a is performed in preference to the load reduction of the engine 12, thereby protecting the engine 12 from heat.

  As described above, it can be confirmed that an abnormality has occurred in the engine 12 when the horsepower factor is equal to or less than the horsepower factor threshold. That is, the “horsepower factor threshold value” is set in advance based on the ratio of the output limited by the engine controller 19 when an abnormality occurs in the engine.

  Further, since the rotational speed of the fan 17 is limited so that the rotational speed of the fan 17 decreases as the horsepower factor decreases when an abnormality occurs in the engine 12, the engine 12 increases as the output limit of the engine 12 increases. Can be reduced.

  Therefore, it is possible to prevent an excessive load from being applied to the engine 12 by driving the fan 17 in a situation where an abnormality has occurred in the engine 12.

  Moreover, according to 1st Embodiment, there can exist the following effects.

  The engine controller 19 does not calculate the horsepower factor, but the main controller 20 calculates the horsepower factor. Thus, it is possible to efficiently specify the horsepower factor by adding a function for calculating the horsepower factor to the main controller 20 that controls the fan 17 without adding an extra function to the engine controller 19. it can.

  Even in a situation where the horsepower factor is equal to or less than the horsepower factor threshold, it is possible to prohibit the limitation on the rotational speed of the fan 17 when the temperature of the object to be cooled (hydraulic oil and cooling water) exceeds the temperature threshold. Therefore, it is possible to prevent a new problem from occurring due to the temperature rise of the object to be cooled.

  The rotation speed of the fan 17 is limited by multiplying the target rotation speed by the horsepower factor. As a result, the target rotational speed can be limited based on the target rotational speed and the horsepower factor set based on the temperature of the object to be cooled, and therefore the relationship between the magnitude of the horsepower factor and the limiting rate of the target rotational speed separately. It is not necessary to prepare a characteristic indicating the above and to secure an area for storing the characteristic.

  In particular, in the first embodiment, a target rotational speed is set for each temperature detected by a plurality of temperature detectors (water temperature sensor 12a and hydraulic oil temperature sensor 21a) (steps S2 and S4). Is selected (step S5). Thereby, it is possible to reduce the load on the engine 12 while ensuring the cooling capacity by the fan 17 based on the highest temperature.

  Since the fan 17 is driven using the fan pump 15 and the fan motor 16, hydraulic equipment (such as the hydraulic oil tank 21) in the excavator 1 can be used, and the excavator 1 can be configured in a compact manner. it can.

Second Embodiment
In the first embodiment, an example in which the fan 17 is hydraulically driven has been described. However, the driving method of the fan 17 is not limited as long as the fan 17 is driven using the power of the engine 12.

  For example, in the hybrid excavator according to the second embodiment shown in FIG. 7, the fan 17 is driven using the electric power generated by the engine 12. Hereinafter, with reference to FIG. 7, a different part from 1st Embodiment of the drive system 11 which concerns on 2nd Embodiment is demonstrated.

  Specifically, the drive system 11 provided in the hybrid excavator according to the second embodiment is connected to the output shaft of the engine 12, and a generator motor (generator) 25 that generates power using the power of the engine 12, and the generator motor The electric motor 26 that operates using the electric power generated by the electric motor 25 and the inverter 27 that controls electric power supplied from the electric generator motor 25 to the electric motor 26 are provided.

  The generator motor 25 has a function of operating as a generator using the power of the engine 12 and a function of operating as a motor using electric power from a power storage device (not shown). As the generator motor 25 operates as an electric motor, the engine 12 is assisted by the power of the generator motor 25.

  The electric motor 26 has a rotating shaft (reference numeral omitted) connected to the fan 17.

  The inverter 27 is electrically connected to the main controller 20. Further, the inverter 27 adjusts the electric power supplied from the generator motor 25 to the motor 26 in accordance with a command from the main controller 20.

  The main controller 20 outputs a command for limiting the power supplied from the generator motor 25 to the motor 26 to the inverter 27 when the horsepower factor is equal to or less than the horsepower factor threshold value. Specifically, the main controller 20 outputs a command corresponding to the target rotational speed to the inverter 27 in step S12 shown in FIG.

  According to the second embodiment, since an existing hybrid device (such as the generator motor 25) of the hybrid excavator can be used, the hybrid excavator can be configured in a compact manner.

  Further, since the rotational speed of the fan 17 is electrically controlled, the rotational speed of the fan 17 can be accurately controlled as compared with the case where the rotational speed of the fan 17 is hydraulically controlled.

  In addition, this invention is not limited to the said embodiment, For example, the following aspects can also be employ | adopted.

  The main controller 20 is not limited to storing the normal torque map M1. The horsepower factor may be provided from the engine controller 19 to the main controller 20.

  When the main controller 20 stores the normal torque map M1, the main controller 20 is not limited to calculating the horsepower factor by comparing the maps. For example, if the engine speed at the current time and the output torque of the engine 12 at that speed are provided from the engine controller 19 to the main controller 20, the main controller 20 can calculate the horsepower factor.

  The method of limiting the rotational speed of the fan 17 is not limited to multiplying the target rotational speed by the horsepower factor, and the main controller 20 rotates the fan 17 so that the rotational speed of the fan 17 decreases as the horsepower factor decreases. What is necessary is just to control a number. For example, when the target flow rate of the fan pump 15 (see FIG. 1) is set in step S2 of FIG. 6 instead of the target rotational speed, the target flow rate is obtained by multiplying the target flow rate of the fan pump 15 by the horsepower factor in step S11. Can be corrected. In step S12, the main controller 20 outputs a command corresponding to the corrected target flow rate to the electromagnetic proportional valve 23, so that the lower the horsepower factor, the lower the fan 17 rotational speed. Can be limited.

  For example, the main controller 20 sets the target rotational speed of the fan 17 based on the temperature of the object to be cooled (hydraulic oil, cooling water, etc.), and the relationship between the magnitude of the horsepower factor and the limiting ratio of the target rotational speed. The characteristic to be shown may be stored in advance, and the output of the engine 12 may be limited based on this characteristic and the horsepower factor.

  In the above embodiment, a plurality of temperature detectors (water temperature sensor 12a and hydraulic oil temperature sensor 21a) for detecting the temperatures of separate objects to be detected (cooling water and hydraulic oil) are exemplified. A common object to be detected may be detected.

  The construction machine is not limited to an excavator, and may be a crane and a dismantling machine. The construction machine is not limited to a hydraulic or hybrid construction machine, and may be an electric type.

M1 normal torque map (an example of normal output information and current output information)
M2 torque limit map (example of current output information)
1 Hydraulic excavator (an example of construction machinery)
12 Engine 12a Water temperature sensor (example of temperature detector)
15 Fan pump 15a Regulator 16 Fan motor 17 Fan 19 Engine controller 20 Main controller (fan controller)
21a Hydraulic oil temperature sensor (example of temperature detector)
25 Generator motor (an example of a generator)
26 Electric motor 27 Inverter

Claims (7)

A construction machine,
Engine,
A fan that operates using the power of the engine;
A fan controller for controlling the rotational speed of the fan;
An engine controller that limits the output of the engine rather than the output of the engine in a normal state when an abnormality occurs in the engine,
The fan controller obtains information for specifying a horsepower factor indicating a ratio of a current output of the engine to an output of the engine in a normal state from the engine controller, and the horsepower factor is Limiting the number of revolutions of the fan so that the smaller the horsepower factor is, the smaller the number of revolutions of the fan is when it is less than or equal to a preset horsepower factor threshold value to confirm that an abnormality has occurred in the engine; Construction machinery. The construction machine according to claim 1,
The fan controller stores in advance normal output information regarding the output of the engine in a normal state, acquires current output information regarding the current output of the engine from the engine controller, and further includes the normal output information and A construction machine that calculates the horsepower factor based on the current output information. The construction machine according to claim 1 or 2, further comprising a temperature detector that detects a temperature of an object to be cooled that is cooled by the fan,
The fan controller rotates the fan when the horsepower factor is equal to or less than the horsepower reduction threshold value and the temperature of the object to be cooled detected by the temperature detector exceeds a preset temperature threshold value. Construction machinery that prohibits the number limit. The construction machine according to claim 1 or 2, further comprising at least one temperature detector that detects a temperature of an object to be cooled that is cooled by the fan,
The fan controller sets a target rotational speed of the fan based on the temperature of the object to be cooled detected by the temperature detector, and the target rotational speed when the horsepower factor is equal to or less than the horsepower factor threshold value. A construction machine that limits the target rotational speed of the fan by multiplying the horsepower factor with respect to the fan. The construction machine according to claim 4, comprising a plurality of the temperature detectors,
The fan controller sets the target rotational speed of the fan based on the temperature detected by each temperature detector, selects the largest target rotational speed from all the target rotational speeds, and selects the selected target A construction machine that limits the target rotational speed of the fan by multiplying the rotational speed by the horsepower factor. The construction machine according to any one of claims 1 to 5, wherein the construction machine is connected to the engine and has a function of changing a tilt, and is operated by hydraulic oil supplied from the hydraulic pump and the fan. A hydraulic motor having a rotating shaft connected to
The fan controller is a construction machine that outputs a command for reducing the tilt of the hydraulic pump when the horsepower factor is equal to or less than the horsepower factor threshold value. The construction machine according to any one of claims 1 to 5, wherein the construction machine is connected to the engine and generates electric power using power of the engine, and is operated by the electric power generated by the generator and the fan. An electric motor having a rotating shaft connected to the inverter, and an inverter that controls electric power supplied from the generator to the electric motor,
The said fan controller is a construction machine which outputs the instruction | command for restrict | limiting the electric power supplied from the said generator to the said motor to the said inverter, when the said horsepower factor is below the said horsepower factor threshold value.

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