JP2021050666A - Cooling fan control device, cooling device and cooling fan control method - Google Patents

Abstract

To provide a cooling fan control device, a cooling device and a cooling fan control method capable of appropriately cooling a cooling object by effectively using power capacity of a power supply.SOLUTION: A cooling fan control device 40 controls rotation speeds of a plurality of fans 25, 26 and 27 which is driven with power supply from an alternator 30 and has a different main cooling object. The cooling fan control device 40 has a controller 42 which optimizes target rotation speeds of respective fans 25, 26 and 27 within a range where power consumption of the fans 25, 26 and 27 does not exceed the power capacity of the alternator 30 on the basis of the power capacity of the alternator 30 and a total of required power according to cooling conditions of the cooling objects of respective fans 25, 26 and 27.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cooling fan control device, a cooling device, and a cooling fan control method for controlling the rotation speeds of a plurality of cooling fans.

In work machines such as hydraulic excavators, radiators for cooling the engine, oil coolers for cooling the hydraulic oil supplied and discharged to each hydraulic actuator, and aftercoolers for cooling the engine intake compressed by the turbo supercharger, etc. A cooling package, which is a cooling unit including a heat exchanger and an electric cooling fan corresponding to each of these heat exchangers, is installed. Each cooling fan controls the rotation speed, that is, the fan speed separately. Conventionally, each cooling fan has a predetermined upper limit fan speed so as not to exceed the current capacity of the alternator serving as a power supply (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-9517

In the cooling package, if the cooling states of multiple heat exchangers are uneven, the fan speed of the cooling fan for the low temperature heat exchanger is suppressed, while the fan speed of the cooling fan for the high temperature heat exchanger is increased. It is hoped that it will increase.

For example, when the water temperature is relatively high and the oil temperature is relatively low, such as when the radiator is clogged, the fan speed of the cooling fan for cooling the oil cooler or aftercooler may be relatively low, but for radiator cooling. The fan speed of the cooling fan is required.

Further, when the work machine is used in a high place, the performance of the radiator is lower than that of the oil cooler because the air density is low, so it is desired to increase the fan speed of the cooling fan for cooling the radiator.

Further, when an attachment such as a hammer is used, the fan speed of the cooling fan for cooling the oil cooler is required as compared with the fan speed of the cooling fan for cooling the radiator.

However, if the upper limit fan speed of the cooling fan is predetermined, the total required current of the cooling fan is relatively small, and even if the alternator has a margin of current capacity, the cooling fan may be set to be equal to or higher than the upper limit fan speed. Can not.

The present invention has been made in view of these points, and provides a cooling fan control device, a cooling device, and a cooling fan control method capable of appropriately cooling a cooling target by efficiently utilizing the power capacity of a power supply. The purpose is to do.

The invention according to claim 1 is a cooling fan control device that is driven by power supply from a power supply and controls the rotation speeds of a plurality of cooling fans whose main cooling targets are different from each other. Based on the total required power according to the cooling state of the cooling target for each cooling fan, the rotation that optimizes the target rotation speed of each cooling fan within the range where the power consumption of the cooling fan does not exceed the power capacity of the power supply. It is equipped with a number setting means.

The invention according to claim 2 is the case where the rotation speed setting means in the cooling fan control device according to claim 1 exceeds the power capacity of the power supply power supply when the total required power according to the cooling state of the cooling target for each cooling fan exceeds. Is to set the target rotation speed of each cooling fan to a predetermined upper limit target rotation speed, and if the total required power according to the cooling state of the cooling target for each cooling fan does not exceed the power capacity of the power supply. , The target rotation speed of some cooling fans can be set beyond the upper limit target rotation speed.

The invention according to claim 3 comprises an alternator as a power supply, a heat exchanger, and a plurality of cooling fans driven by the electric power generated by the alternator and having different main cooling target heat exchangers. A cooling device including the cooling fan control device according to claim 1 or 2, which controls the rotation speeds of a plurality of cooling fans, respectively.

The invention according to claim 4 is a cooling fan control method that is driven by power supply from a power supply and controls the rotation speeds of a plurality of cooling fans whose main cooling targets are different from each other. Based on the total required power according to the cooling state of the cooling target for each cooling fan, the target rotation speed of each cooling fan is optimized within the range where the power consumption of the cooling fan does not exceed the power capacity of the power supply. Is.

According to the fifth aspect of the present invention, in the cooling fan control method according to the fourth aspect, when the total required power of each cooling fan according to the cooling state of the cooling target exceeds the power capacity of the power supply, each cooling fan. If the target rotation speed of is set to a predetermined upper limit target rotation speed and the total required power according to the cooling state of the cooling target for each cooling fan does not exceed the power capacity of the power supply, some cooling The target rotation speed of the fan can be set beyond the upper limit target rotation speed.

According to the invention of claim 1, when the required power has a margin according to the cooling state of the cooling target, the power of the cooling fan having a small required power is suppressed, and the power of the cooling fan having a large required power is suppressed by that amount. It becomes possible to appropriately cool the cooling target by efficiently using the power capacity of the power supply.

According to the invention according to claim 2, when the total required power according to the cooling state of the cooling target for each cooling fan does not exceed the power capacity of the power supply, the target rotation speed of some cooling fans is set. Since it can be set beyond the upper limit target rotation speed, the target rotation speed can be increased without being limited to the upper limit target rotation speed for a cooling fan that requires a large amount of power, and the cooling target can be appropriately cooled.

According to the invention of claim 3, the electric power of the alternator can be effectively used, and the heat exchanger to be cooled can be appropriately cooled by the cooling fan without increasing the size of the alternator.

According to the invention of claim 4, if there is a margin in the required power according to the cooling state of the cooling target, more power is supplied to the cooling fan having a large required power, and the power capacity of the power supply is supplied. Can be used efficiently to appropriately cool the object to be cooled.

According to the invention of claim 5, when the total required power according to the cooling state of the cooling target for each cooling fan does not exceed the power capacity of the power supply, the target rotation speed of some cooling fans is set. Since the setting exceeds the upper limit target rotation speed, for a cooling fan that requires a large amount of power, the target rotation speed can be increased without being limited by the upper limit target rotation speed, and the cooling target can be appropriately cooled.

It is a block diagram which shows one Embodiment of the cooling device which includes the cooling fan control device which concerns on this invention. It is explanatory drawing which shows the cooling fan control device of the same as above. It is explanatory drawing which shows typically the process of the rotation speed setting means of the cooling fan control device. It is explanatory drawing which shows an example of the table of the power generation current of the supply power with respect to the engine speed of the cooling fan control device of the same as above. (A) is an explanatory diagram showing an example of a table of required rotation speeds of the first cooling fan with respect to the temperature of the first heat exchanger of the same cooling fan control device, and (b) is the second of the same cooling fan control device. An explanatory diagram showing an example of a table of required rotation speeds of the second cooling fan with respect to the temperature of the heat exchanger, (c) is the need for the third cooling fan with respect to the temperature of the third heat exchanger of the cooling fan controller as above. It is explanatory drawing which shows an example of the table of the number of rotations.

Hereinafter, the present invention will be described in detail based on the embodiment shown in FIGS. 1 to 5.

In FIG. 1, reference numeral 11 denotes a cooling device. The cooling device 11 of the present embodiment is a cooling device for a work machine such as a hydraulic excavator. The cooling device 11 includes a plurality of heat exchangers to be cooled. In the present embodiment, the heat exchangers are the radiator 15 which is the first heat exchanger through which the engine cooling water passes, and the oil cooler 16 which is the second heat exchanger through which the hydraulic oil supplied to and discharged from the hydraulic actuator passes. And an aftercooler 17, which is a third heat exchanger through which air compressed by a turbo supercharger (not shown) passes.

Further, the cooling device 11 includes a cooling fan arranged for each heat exchanger. That is, the cooling device 11 includes a plurality of cooling fans. The cooling fans are arranged to face each other with respect to the heat exchanger. The cooling fan is driven by the driving means. The drive means is an electric drive means, and is driven by being supplied with power from a power supply. That is, the cooling fan of the present embodiment is an electric fan. In the present embodiment, the cooling fans are the radiator fan 25, which is the first cooling fan for cooling the radiator 15, the oil cooler fan 26, which is the second cooling fan for cooling the oil cooler 16, and the aftercooler 17. It has an aftercooler fan 27 which is a third cooling fan for cooling. As the driving means, the electric motor 25m for the radiator fan, which is the first electric motor for driving the radiator fan 25, and the electric motor 26m for the oil cooler fan, which is the second electric motor for driving the oil cooler fan 26, are used. It has an electric motor 27m for an aftercooler fan, which is a third electric motor for driving the aftercooler fan 27.

An alternator 30 is used as a power supply to supply power to the drive means. The alternator 30 is connected to the output shaft of the engine 31 and is driven by the engine 31 to generate electric power, and the generated electric power is stored in the battery 32. The rotation speed of the alternator 30 is set according to the rotation speed of the engine 31, and the higher the rotation speed of the alternator 30, the larger the generated current. Normally, the rotation speed of the engine 31 and the rotation speed of the alternator 30 have a positive correlation, and in the present embodiment, the rotation speed of the engine 31 and the rotation speed of the alternator 30 are in a proportional relationship. The battery 32 is electrically connected to the electric motors 25m, 26m and 27m, and the electric power generated by the alternator 30 is supplied to the electric motors 25m, 26m and 27m via the battery 32. Further, the rotation speed of the engine 31 is detected by the rotation speed detecting means 33.

Further, the cooling device 11 includes a temperature sensor arranged for each heat exchanger. That is, the cooling device 11 includes a plurality of temperature sensors. The temperature sensor directly or indirectly acquires information related to the temperature of each heat exchanger or the temperature of the fluid passing through each heat exchanger. In the present embodiment, the temperature sensor includes a first temperature sensor 35 for the radiator 15, a second temperature sensor 36 for the oil cooler 16, and a third temperature sensor 37 for the aftercooler 17. In the present embodiment, the first temperature sensor 35 directly or indirectly detects the temperature of the engine cooling water passing through the radiator 15. The second temperature sensor 36 directly or indirectly detects the temperature of the hydraulic oil passing through the oil cooler 16. Further, the third temperature sensor 37 directly or indirectly detects the temperature of the air passing through the aftercooler 17.

Further, the cooling device 11 includes a cooling fan control device 40. The cooling fan control device 40 controls the rotation speeds (fan speeds) of the plurality of cooling fans. In the present embodiment, the cooling fan control device 40 controls the rotation speeds of the fans 25, 26, and 27, that is, the rotation speeds of the electric motors 25m, 26m, and 27m, respectively. The cooling fan control device 40 includes a controller 42.

The controller 42 may consist of a computer. The controller 42 is electrically connected to the driving means of the cooling fan and the temperature sensor. In the present embodiment, the controller 42 includes an electric motor for a radiator fan 25 m, an electric motor for an oil cooler fan 26 m, an electric motor for an aftercooler fan 27 m, a rotation speed detecting means 33, a first temperature sensor 35, and a second temperature. It is electrically connected to the sensor 36, the third temperature sensor 37, and the like.

Then, in the present embodiment, the controller 42 has a function of a rotation speed setting means. The controller 42 cools each cooling fan within a range in which the power consumption of each cooling fan does not exceed the power capacity of the alternator 30 based on the power capacity of the alternator 30 and the total power required according to the cooling state of the cooling target for each cooling fan. Optimize the target rotation speed of the fan. Hereinafter, in the present embodiment, "electric power" will be described as "current".

The controller 42 contains a table of generated current of the alternator 30 with respect to the rotation speed of the engine 31 (Fig. 4), current values required for controlling electrical components other than the electric motors 25m, 26m, and 27m of the fans 25, 26, and 27, and electric motor. For the current values supplied to the motors 25m, 26m, 27m, the rotation speed table of the electric motors 25m, 26m, 27m, and the temperatures TR, TO, TA detected by the first to third temperature sensors 35, 36, 37. Fans 25, 26, 27 or electric motors 25m, 26m, 27m rotation speeds NR, NO, NA tables T1, T2, T3 (Figs. 5 (a) to 5 (c)), and fans 25, 26, The upper limit target rotation speed of 27 (electric motors 25m, 26m, 27m) is stored in advance.

As an example is shown in FIG. 4, the generated current of the alternator 30 basically has a positive correlation with the rotation speed of the engine 31. A plurality of tables of the generated current of the alternator 30 with respect to the rotation speed of the engine 31 may be stored in advance according to, for example, the ambient temperature of the alternator 30.

As an example is shown in FIG. 5A, for the table T1 having a rotation speed NR of the radiator fan 25 or the electric motor 25 m for the radiator fan with respect to the temperature TR, the temperature TR is equal to or less than the predetermined first temperature threshold TR1 (TR). In the case of ≦ TR1), the rotation speed NR is constant at a predetermined first rotation speed NR1. When the temperature TR is larger than the first temperature threshold TR1 and less than the predetermined second temperature threshold TR2 (TR1 <TR <TR2), the rotation speed NR is from the first rotation speed NR1 to the predetermined second. There is a positive correlation between the rotation speeds NR2 (NR1 <NR2), for example, a proportional relationship. Further, when the temperature TR is equal to or higher than the second temperature threshold value TR2 (TR2 ≦ TR), the rotation speed NR is constant at the second rotation speed NR2.

Similarly, as shown in FIG. 5B, for the table T2 having the rotation speed NO of the oil cooler fan 26 or the electric motor 26m for the oil cooler fan with respect to the temperature TO, the temperature TO is the predetermined first temperature. When the threshold value is TO1 or less (TO ≦ TO1), the rotation speed NO is constant at a predetermined first rotation speed NO1. When the temperature TO is larger than the first temperature threshold TO1 and less than the predetermined second temperature threshold TO2 (TO1 <TO <TO2), the rotation speed NO is from the first rotation speed NO1 to the predetermined second. There is a positive correlation between the rotation speeds NO2 (NO1 <NO2), for example, a proportional relationship. Further, when the temperature TO is equal to or higher than the second temperature threshold value TO2 (TO2 ≦ TO), the rotation speed NO is constant at the second rotation speed NO2.

Further, as shown in FIG. 5 (c), for the table T3 having the rotation speed NA of the aftercooler fan 27 or the electric motor 27 m for the aftercooler fan with respect to the temperature TA, the temperature TA is a predetermined first temperature threshold value. When TA1 or less (TA ≤ TA1), the rotation speed NA is constant at a predetermined first rotation speed NA1. When the temperature TA is larger than the first temperature threshold TA1 and less than the predetermined second temperature threshold TA2 (TA1 <TA <TA2), the rotation speed NA is from the first rotation speed NA1 to the predetermined second. There is a positive correlation between the rotation speeds NA2 (NA1 <NA2), for example, a proportional relationship. Further, when the temperature TA is equal to or higher than the second temperature threshold value TA2 (TA2 ≦ TA), the rotation speed NA is constant at the second rotation speed NA2.

The upper limit target rotation speeds of the fans 25, 26, 27 (electric motors 25m, 26m, 27m) may be the same as or different from each other. Further, the upper limit target rotation speed may be set in advance according to the rotation speed of the engine 31. For example, the upper limit target rotation speed is the current capacity of the power supply, that is, the capacity obtained by subtracting the current value required for controlling other electrical components from the generated current of the alternator 30, equally divided by the number of cooling fans, that is, in this implementation. In the embodiment, the number of rotations corresponding to a predetermined current value equal to or less than the current value divided into three equal parts may be set in advance.

Then, as shown in FIGS. 1 and 2, the controller 42 has a calculation means 43 for calculating the target rotation speeds TNR, TNO, and TNA of the fans 25, 26, and 27, and a target rotation speed calculated by the calculation means 43. It is equipped with an output means 44 that outputs control signals of fans 25, 26, and 27 so as to be TNR, TNO, and TNA.

In the present embodiment, the calculation means 43 calculates the target rotation speeds TNR, TNO, and TNA of the fans 25, 26, and 27 by calculating the target rotation speeds of the electric motors 25m, 26m, and 27m. The calculation means 43 is the sum of the current capacity of the alternator 30 and the required currents of the heat exchangers to be cooled for each of the fans 25, 26, and 27, that is, the radiator 15, the oil cooler 16, and the aftercooler 17. Based on the above, the optimum fan 25, 26, 27 or electric motor 25m, 26m, 27m is used as long as the current consumption of the electric motors 25m, 26m, 27m of each fan 25, 26, 27 does not exceed the current capacity of the alternator 30. Calculate the target rotation speeds TNR, TNO, and TNA of. For example, when the calculation means 43 has a bias in the cooling state of the object to be cooled by the cooling fan and there is a cooling fan whose required current is smaller than a predetermined current value, the alternator 30 has a margin in the current capacity. The target rotation speed of this cooling fan is increased so that the surplus of the current capacity of the alternator 30 is turned to the cooling fan having a large required current. In other words, the calculation means 43 suppresses the target rotation speed of the cooling fan that has a margin in terms of cooling to decelerate the cooling fan, and the cooling fan that requires the floating current (the cooling target is insufficiently cooled). The target rotation speed of the cooling fan is calculated so as to increase the rotation speed (fan speed) of the cooling fan by turning it to the cooling fan).

The temperature detected by the temperature sensor is input to the calculation means 43 as the cooling state of the heat exchanger to be cooled. Preferably, the average value of the temperature detected by the temperature sensor is input to the calculation means 43. That is, the averaging means is electrically connected to the calculation means 43. In the present embodiment, the moving average values of the temperatures TR, TO, and TA detected by the first to third temperature sensors 35, 36, and 37 are input to the calculation means 43. That is, the first to third averaging means 45, 46, and 47 are electrically connected to the calculation means 43. The first to third averaging means 45, 46, 47 are electrically connected to the first to third temperature sensors 35, 36, 37, and these first to third temperature sensors 35, 36, 37 are connected. The temperature TR, TO, and TA output from the above are averaged in a predetermined moving average time and output to the calculation means 43. The predetermined moving average time may be set in advance, or may be arbitrarily set by an operator or the like. Hereinafter, the temperatures TR, TO, and TA indicate the temperature detected by the first to third temperature sensors 35, 36, and 37, and the first to third averaging means 45, 46, 47. It shall include both the case where the temperature is averaged by and the case where the temperature is averaged by.

Next, the operation of the illustrated embodiment will be described.

When controlling the rotation speeds of the fans 25, 26, and 27, the controller 42 first uses the calculation means 43 to detect the rotation speeds based on the table of the generated current of the alternator 30 with respect to the rotation speeds of the engine 31 (FIG. 4). The generated current of the alternator 30 is calculated from the rotation speed of the engine 31 detected by 33. When calculating the generated current, the table may be selected in consideration of the ambient temperature of the alternator 30. In that case, a temperature sensor that detects the ambient temperature of the alternator 30 may be further provided.

Next, the controller 42 subtracts the current value required for controlling the electrical components other than the electric motors 25m, 26m, and 27m from the calculated current generated by the alternator 30 in the calculation means 43. Further, the calculation means 43 is a table T1, T2, T3 (FIGS. 5A to 5A) of fans 25, 26, 27 for temperatures TR, TO, TA or rotation speeds NR, NO, NA of electric motors 25m, 26m, 27m. From FIG. 5C), the required rotation speed, that is, the required current is calculated.

After that, the controller 42 determines the fans 25, 26 in the calculation means 43 based on the current capacity of the alternator 30 and the required currents of the fans 25, 26, 27, that is, the sum of the required currents of the electric motors 25 m, 26 m, and 27 m. , 27 target rotation speeds TNR, TNO, TNA are calculated to be optimized. In the present embodiment, the calculation means 43 subtracts the current value required for controlling the electric components other than the electric motors 25m, 26m, and 27m from the current generated by the alternator 30, and the electric motors 25m, 26m, and 27m. Calculate to optimize the target rotation speeds TNR, TNO, and TNA of the fans 25, 26, and 27 based on the magnitude relationship with the required current.

The calculation means 43 preferably sequentially calculates the target rotation speed. That is, the calculation means 43 calculates one target rotation speed, and the power consumption corresponding to the calculated target rotation speed, the current consumption in the present embodiment, the current capacity of the power supply, and the alternator 30 in the present embodiment. The current value required for controlling electrical components other than the electric motors 25m, 26m, and 27m is subtracted from the current generated by the electric motor, and the current value is further subtracted to calculate the next other target rotation speed. That is, in the present embodiment, the setting of the target rotation speed by the calculation means 43 has a priority. The order of priority is, for example, the order of the heat capacity of the cooling target, or the order in which the cooling target is likely to overheat. This priority may be predetermined, or the priority may be arbitrarily set by an operator or the like. In the present embodiment, the target rotation speed TNR of the radiator fan 25 (electric motor 25m for the radiator fan) is given the highest priority, then the target rotation speed TNO of the oil cooler fan 26 (electric motor 26m for the oil cooler fan), and further after. Calculate in the order of the target rotation speed TNA of the cooler fan 27 (electric motor 27m for the aftercooler fan).

In the present embodiment, as shown in FIG. 3, the calculation means 43 first calculates the target rotation speed TNR of the radiator fan 25 (electric motor for radiator fan 25 m) (processing block for radiator fan (for radiator fan)). Processing sequence) BR). The calculation means 43 calculates the sum of the required currents of the cooling fan (step S1), and the calculated sum and the current capacity of the power supply, that is, the current value required for controlling other electrical components from the generated current of the alternator 30. It is determined whether or not the total sum exceeds the current capacity of the power supply by comparing with the capacity obtained by subtracting (step S2). When the total exceeds the current capacity (YES in step S2), the target rotation speed TNR is maintained at the current rotation speed such as a predetermined upper limit target rotation speed (step S3), and the total is the current. If the capacity is not exceeded (NO in step S2), the target rotation speed TNR is set as the required rotation speed (step S4). At this time, the required rotation speed allows a rotation speed larger than the upper limit target rotation speed. Then, the target rotation speed TNR determined in step S3 or step S4 is output to the output means 44 (FIG. 2), and this target rotation speed TNR is stored as the current rotation speed (step S5).

After that, in the calculation means 43, the oil cooler fan processing block (oil cooler fan processing sequence) BO and the after are the same as in steps S1 to S5 in the radiator fan processing block (radiator fan processing sequence) BR. In the cooler fan processing block (after-cooler fan processing sequence) BA, the total required current of the remaining cooling fans is calculated, and the current value obtained by subtracting the current consumption according to the target rotation speed calculated from the current capacity and Compare the size with the calculated total in the same way, and find the target rotation speed TNO of the oil cooler fan 26 (electric motor 26m for the oil cooler fan) and the target rotation speed TNA of the aftercooler fan 27 (electric motor 27m for the aftercooler fan). Calculate sequentially.

Then, as shown in FIG. 2, in the output means 44, the control signals corresponding to the target rotation speeds TNR, TNO, and TNA calculated by the calculation means 43 are transmitted to the electric motors 25m, 26m, and 27m shown in FIG. Output.

As described above, according to one embodiment, the sum of the power capacity of the alternator 30 and the required power according to the cooling state of the radiator 15, the oil cooler 16, and the aftercooler 17 to be cooled for each of the fans 25, 26, and 27. Based on the above, the target rotation speeds TNR, TNO, and TNA of each fan 25, 26, and 27 are optimized within the range where the power consumption of the fans 25, 26, and 27 does not exceed the power capacity of the alternator 30, so it is subject to cooling. Depending on the cooling state of the radiator 15, oil cooler 16, and aftercooler 17, if there is a margin in the required power, the power of the cooling fan with the smaller required power is suppressed, and that amount is transferred to the cooling fan with the larger required power. , The radiator 15, oil cooler 16, and aftercooler 17 can be appropriately cooled by efficiently using the power capacity of the alternator 30.

Specifically, the controller 42 is a fan when the total required power according to the cooling state of the cooling target for each fan 25, 26, 27 (electric motor 25m, 26m, 27m) exceeds the power capacity of the power supply. Target rotation speeds of 25, 26, 27 (electric motors 25m, 26m, 27m) TNR, TNO, TNA are set to predetermined upper limit target rotation speeds, and every fan 25, 26, 27 (electric motors 25m, 26m, 27m) If the total required power according to the cooling state of the cooling target does not exceed the power capacity of the power supply, the target rotation speeds of fans 25, 26, 27 (electric motors 25m, 26m, 27m) TNR, TNO, TNA Since any of the above can be set beyond the upper limit target rotation speed, if the total required power according to the cooling state of the cooling target for each cooling fan does not exceed the power capacity of the power supply, some It is also possible to set the target rotation speed of the cooling fan beyond the upper limit target rotation speed, and for cooling fans that require a large amount of power, the target rotation speed is increased without being limited to the upper limit target rotation speed to be cooled. Can be cooled properly.

By providing the above-mentioned cooling fan control device 40, the power of the alternator 30 can be effectively used, and the power capacity of the alternator 30 can be increased to increase the power capacity without improving the cooling capacity of the cooling fan. , 26, 27 can provide a cooling device 11 capable of appropriately cooling the heat exchanger to be cooled. That is, it is not necessary to newly develop and install a large alternator 30, there is no need to change the design of the work machine, and the cooling device 11 can cool the heat exchanger inexpensively and appropriately.

That is, in the conventional example in which the upper limit target rotation speed is set according to the standard specifications and applications, the target rotation speed cannot be set higher than the upper limit target rotation speed even though there is a margin in the power capacity. There was a risk of insufficient cooling of the object to be cooled due to specifications that deviate from the standard specifications, work environment (high temperature / high altitude), or work content. In addition, it was not realistic to increase the size of the alternator 30 in order to increase the power capacity from the viewpoints of cost and vehicle body space. In the present embodiment, these problems can be solved, and a cooling device 11 which is small in size and has good cooling efficiency can be provided.

In the above embodiment, the cooling fan is not limited to the fans 25, 26, and 27, and the cooling fan control device 40 can be applied to an electric fan that cools any other cooling target.

The number of cooling fans is not limited to three as long as it is plural, and may be two or four or more.

The present invention has industrial applicability for businesses engaged in the manufacturing industry, sales industry, and the like of cooling devices used in work machines such as hydraulic excavators.

11 Cooling device
15 Radiator, a heat exchanger to be cooled
16 Oil cooler, which is the heat exchanger to be cooled
17 Aftercooler, which is the heat exchanger to be cooled
25 Radiator fan, which is a cooling fan
26 Oil cooler fan, which is a cooling fan
27 Aftercooler fan, which is a cooling fan
30 Alternator that is the power supply
40 Cooling fan controller
42 Controller with the function of rotation speed setting means

Claims (5)

It is a cooling fan control device that is driven by the power supply from the power supply and controls the rotation speeds of a plurality of cooling fans whose main cooling targets are different.
Based on the power capacity of the power supply and the total power required for each cooling fan according to the cooling state of the cooling target, the target rotation of each cooling fan within the range where the power consumption of the cooling fan does not exceed the power capacity of the power supply. A cooling fan control device characterized by having a rotation speed setting means for optimizing the number. When the total required power of each cooling fan according to the cooling state of the cooling target exceeds the power capacity of the power supply, the rotation speed setting means sets the target rotation speed of each cooling fan to a predetermined upper limit target rotation speed. If the total required power for each cooling fan according to the cooling state of the cooling target does not exceed the power capacity of the power supply, the target rotation speed of some cooling fans will be exceeded. The cooling fan control device according to claim 1, wherein the cooling fan control device can be set. The alternator that serves as the power supply and
With a heat exchanger
Multiple cooling fans that are driven by the electric power generated by the alternator and have different main heat exchangers to be cooled.
The cooling fan control device according to claim 1 or 2, which controls the rotation speeds of the plurality of cooling fans, respectively.
A cooling device characterized by being equipped with. It is a cooling fan control method that is driven by power supply from a power supply and controls the rotation speeds of a plurality of cooling fans whose main cooling targets are different.
Based on the power capacity of the power supply and the total power required for each cooling fan according to the cooling state of the cooling target, the target rotation of each cooling fan within the range where the power consumption of the cooling fan does not exceed the power capacity of the power supply. A cooling fan control method characterized by optimizing the number. When the total power required for each cooling fan according to the cooling state of the cooling target exceeds the power capacity of the power supply, the target rotation speed of each cooling fan is set to a predetermined upper limit target rotation speed, and the cooling fan is set. If the total required power according to the cooling state of each cooling target does not exceed the power capacity of the power supply, the target rotation speed of some cooling fans can be set to exceed the upper limit target rotation speed. 4. The cooling fan control method according to claim 4.

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