JP2016030999A - Cooler for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of difficulty in installing, in an apparatus for cooling an object to be cooled in a construction machine by driving a plurality of cooling fans by using a plurality of motors corresponding to the fans, a large-sized power generator for driving each motor in a limited space.MEANS FOR SOLVING THE PROBLEM: A cooler comprises: a plurality of cooling fans (42A to 42I) for cooling objects (11 to 13) to be cooled; a plurality of motors (42A to 42I) for rotationally driving the respective cooling fans (42A to 42I); an engine (20); and a power generation unit (30) that is driven by force output by the engine (20) to generate power to be supplied to the respective motors. The power generation unit (30) includes: an input shaft (36) that is rotationally driven by the force of the engine (20); and a plurality of power generators (32A to 32I) that are arranged so as to line up along an axis direction of the input shaft (36) and individually generate power by means of the rotation of the input shaft (36).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cooling device provided in a construction machine such as a hydraulic excavator.

  A construction machine such as a hydraulic excavator is generally equipped with a blower for cooling various objects to be cooled, such as a radiator, an oil cooler, and an intercooler. The blower device includes a fan connected to the engine, and the fan is rotated by the engine to form cooling air and supplies the cooling air to the object to be cooled.

  As this type of construction machine, Patent Document 1 includes a radiator, an oil cooler, and an intercooler as the cooling object, and a first cooling fan, a second cooling fan, and a third cooling fan for supplying cooling air to the radiator, oil cooler, and intercooler, respectively. A hydraulic excavator with a cooling fan is disclosed. Of the first to third cooling fans, the first cooling fan is directly driven by an engine, and the second and third cooling fans are driven by a hydraulic motor. Patent Document 1 describes that the cooling fan may be driven by an electric motor.

JP 2007-198031 A

  When each of the plurality of cooling fans is driven by an electric motor, there is an advantage that each cooling fan can be driven at a speed independent of the rotational speed of the engine. On the other hand, necessary electric power is supplied to each electric motor. However, a large generator is necessary, and it is difficult to secure the installation space. In particular, in construction machines such as hydraulic excavators, the space for mounting various devices is extremely limited, and it is difficult to reasonably arrange a large generator near the engine that is the power source. .

  In view of such circumstances, the present invention is an apparatus for cooling a cooled object of a construction machine, wherein the cooled object is cooled by driving a plurality of cooling fans by a plurality of electric motors, respectively. And it aims at providing the cooling device which can produce | generate electric power required for the drive of each said cooling fan in the limited space.

  The present invention provides an apparatus for cooling at least one object to be cooled provided in a construction machine, and each of them is rotationally driven to form cooling air for cooling the object to be cooled. A plurality of cooling fans, a plurality of electric motors that rotationally drive these cooling fans, an engine that generates and outputs power, and a power that is output from the engine, thereby being supplied to each of the motors. And a power generation unit that generates electric power. The power generation unit is arranged so as to be aligned along an input shaft that is rotationally driven by the power of the engine and the axial direction of the input shaft, and each of the power generation units individually generates electric power by rotation of the input shaft. And have a machine.

  According to this cooling device, it is possible to generate electric power necessary for driving each electric motor by the power generation unit while arranging the power generation unit in a limited space. Specifically, since the power generation unit includes a plurality of power generators, it is possible to generate sufficient power by these power generators, and these power generators are arranged along a common input shaft. Since each of them generates power separately by rotation of the common input shaft, it is necessary to install a power generation unit compared to using one large generator to generate the same amount of power. Increased freedom of space for.

  This effect is more remarkable when the power generation unit is arranged so that the input shaft of the power generation unit is parallel to the output shaft when the engine has an output shaft for outputting the power. Become.

  It is preferable that the power generation unit further includes a casing that rotatably supports the input shaft and stores the generators collectively. This casing can perform both collective protection of each generator and support of the input shaft.

  When each of the generators has a stator and a rotor and generates electric power by relative rotation of the rotor with respect to the stator, the rotor of each generator follows the axial direction of the input shaft. Fixed on the outer peripheral surface of the input shaft so as to be lined up, and fixed on the inner surface of the casing so that the stator of each generator surrounds the rotor from the outside in the rotational radius direction, respectively. preferable. According to this arrangement, it is possible to rationally construct a plurality of generators with a compact structure by effectively using the input shaft and the casing.

  In this case, it is preferable that a cooling flow path that allows the flow of the cooling medium is formed inside the casing. When the cooling medium flows through the cooling flow path, the stators of the generators fixed to the casing can be efficiently cooled together.

  The power generation unit includes, as the plurality of generators, generators corresponding to the plurality of electric motors, respectively, and the electric motors are individually supplied so that each generator can supply electric power to the electric motors corresponding to the generators. It is preferable that it is electrically connected to. In this way, the power generators corresponding to the plurality of electric motors individually supply electric power to each other to facilitate drive control of the electric motors.

  For example, it is preferable that the cooling device further includes a plurality of contacts that individually open and close power supply paths connecting the plurality of electric motors and the plurality of generators corresponding thereto. With the provision of the plurality of contacts, it is possible to individually turn on / off the power supply to each electric motor, and it is possible to control the amount of cooling air generated by the plurality of cooling fans with a high degree of freedom. become.

  Specifically, the cooling device includes a temperature detection unit that detects a temperature of the at least one object to be cooled, and a temperature control unit that switches between opening and closing of the contacts based on the temperature detected by the temperature detection unit. Are preferably further provided. The said temperature control part can control the temperature of the said to-be-cooled body by simple operation of switching of opening / closing of each said contact.

  For example, if these cooling fans are arranged so that the cooling air formed by a plurality of cooling fans strikes the object to be cooled with respect to at least one object to be cooled, the temperature control unit Based on the detected temperature, the number of cooling fans to be operated among the plurality of cooling fans given to the object to be cooled is determined and only the cooling fans are operated. By switching the above, it is possible to appropriately control the temperature of the object to be cooled by adjusting the amount of cooling air supplied to the object to be cooled.

  Further, when the cooling device includes a plurality of objects to be cooled as the at least one object to be cooled, the temperature detection unit includes a plurality of temperature detectors that respectively detect the temperatures of the objects to be cooled, and each of the objects to be cooled It is preferable that at least one of the plurality of cooling fans is provided to the body, and the temperature control unit performs switching of opening / closing of each contact based on a temperature detected by each temperature detector. Thereby, it becomes possible to perform the temperature control of the plurality of objects to be cooled individually and appropriately using the plurality of cooling fans.

  As described above, according to the present invention, a cooling target of a construction machine is cooled by driving a plurality of cooling fans by a plurality of electric motors, respectively, and each cooling fan is limited in a limited space. A cooling device capable of generating electric power necessary for driving is provided.

It is a side view which shows the hydraulic shovel which is an example of the construction machine with which the cooling device which concerns on embodiment of this invention is mounted. It is a system block diagram which shows the said cooling device. It is a front view which shows arrangement | positioning of several cooling device cooled by the said cooling device, and each cooling fan for the cooling. It is a cross-sectional side view which shows the electric power generation unit in the said cooling device. It is a front view which shows the 1st modification of arrangement | positioning of each said cooler and each cooling fan. It is a front view which shows the 2nd modification of arrangement | positioning of each said cooler and each cooling fan. It is a block diagram which shows the function structure of the controller of the said cooling device. It is a flowchart which shows the control operation which the said controller performs. It is a graph which shows the example of the temperature control which the said controller performs.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a hydraulic excavator which is an example of a construction machine on which a cooling device according to an embodiment of the present invention is mounted. The hydraulic excavator includes a lower traveling body 1, an upper revolving body 2 that is turnably mounted thereon, and a excavation attachment 3 that is attached to the upper revolving body 2. The upper swing body 2 has an upper frame 4 on which a cabin 5, an engine room 6 and the like are mounted. And in this engine room 6, the to-be-cooled body and the main part of the said cooling device for cooling this are accommodated.

  FIG. 2 shows the object to be cooled and the main components of the cooling device. This embodiment includes a plurality of objects to be cooled, that is, a first cooler 11, a second cooler 12, and a third cooler 13. The cooling device includes an engine 20 that is a power source for cooling, a power generation unit 30 that is driven by the engine 20 to generate power, and receives each of the coolers that receives power generated by the power generation unit 30. A blower 40 that forms cooling air for cooling 11 to 13, a switch unit 50 that is interposed between the power generation unit 30 and the blower 40, a battery 60 that stores electricity, and the blower 40. And a controller 70 that controls the temperature of each of the coolers 11 to 13.

  The first to third coolers 11 to 13 are cooling heats that cool the fluid by exchanging heat between the fluid flowing through the first to third coolers 11 to 13 and the cooling air supplied to the first to third coolers 11 to 13. Therefore, it corresponds to an object to be cooled by the cooling air, that is, an “object to be cooled” according to the present invention. The first cooler 11 is, for example, an oil cooler that cools hydraulic oil used in a hydraulic circuit, and the second cooler 12 is, for example, a radiator that cools engine coolant for cooling the engine 20. The third cooler 13 is an intercooler for cooling engine intake air whose temperature is increased by adiabatic compression by a supercharger, for example.

  The first cooler 11, the second cooler 12, and the third cooler 13, respectively, include a first temperature sensor 14 and a second temperature sensor that detect the temperature of a fluid to be cooled that is a fluid flowing through the cooler. 15 and a third temperature sensor 16 are provided. The temperature of the fluid to be cooled is, for example, the temperature of hydraulic oil in an oil cooler, the temperature of engine cooling water in a radiator, and the temperature of engine intake air adiabatically compressed in an intercooler.

  As shown in FIG. 3, the first to third coolers 11 to 13 according to this embodiment are arranged in a horizontal row in the engine room 6. However, the specific number and arrangement of “at least one object to be cooled” according to the present invention are not limited. In addition, the “cooled body” according to the present invention is not limited to the cooling heat exchangers such as the first to third coolers 11 to 13, and may be cooled by supplying cooling air. Any possible object can correspond to the “cooled object”.

  The engine 20 is a power source for the entire cooling device, and in this embodiment is a power source for driving main actuators of the hydraulic excavator, and generates necessary power upon receiving fuel supply. Specifically, the engine 20 has an engine output shaft 22 that rotates as an output portion of the power.

  The power generation unit 30 includes a plurality of generators, specifically nine generators 32A, 32B, 32C, 32D, 32E, 32F, 32G, 32H and 32I in this embodiment. These generators 32A to 32I are driven by the power supplied from the engine 20, thereby generating electric power individually.

  FIG. 4 shows the details of the power generation unit 30 according to this embodiment. The power generation unit 30 includes a casing 35 and an input shaft 36 in addition to the generators 32A to 32I.

  The casing 35 collectively stores the generators 32A to 32I and supports the input shaft 36 rotatably. The casing 35 illustrated in FIG. 4 includes a cylindrical peripheral wall 35a and a pair of end walls 35b and 35c connected to both ends in the axial direction. The input shaft 36 is a central axis of the peripheral wall 35a. The end walls 35b and 35c respectively support the front and rear end portions of the input shaft 36 via bearings 37 in a state of penetrating the both end walls 35b and 35c. The casing 35 is fixed to an appropriate part in the engine room 6, for example, an appropriate frame or fixed plate constituting the upper swing body 2. In the example shown in FIG. 4, the outer peripheral portion of the end wall 35 c constitutes a flange portion, and this flange portion is fastened to the appropriate portion by a bolt 38.

  The input shaft 36 takes in the power generated by the engine 20 and transmits it to the generators 32A to 32I. In other words, the generators 32 </ b> A to 32 </ b> I generate power by the rotation of the input shaft 36. As shown in FIG. 2, the power generation unit 30 is preferably disposed in the engine room 6 in a posture in which the input shaft 36 is parallel to the engine input shaft 22, thereby further increasing the power generation unit 30 in the engine room 6. Space saving is possible.

  The input shaft 36 is connected to the engine output shaft 22 via a power transmission mechanism 24. The power transmission mechanism 24 transmits the rotational power of the engine output shaft 22 to the input shaft 36 to rotate the input shaft 36. In the example shown in FIG. 2, the power transmission mechanism 24 includes pulleys 25 and 26 fixed to the engine output shaft 22 and the input shaft 36, and a power transmission belt 28 spanned between the pulleys 25 and 26. However, a well-known transmission mechanism can be applied to the power transmission mechanism 24 such as another winding transmission mechanism or a gear mechanism.

  The generators 32 </ b> A to 32 </ b> I are arranged in a state of being aligned in the axial direction of the input shaft 36, and are constructed between the common input shaft 36 and the casing 35. Specifically, each of the generators 32A to 32I includes a stator (stator) 33 fixed to the casing 35, and a rotor (rotor) 34 fixed to the input shaft 36 and rotated integrally therewith. Have.

  Each stator 33 has a plurality of stator cores 33a and a plurality of exciting coils 33b formed around each stator core 33a. Each stator core 33a has a circumference on the inner peripheral surface of the peripheral wall 35a of the casing 35. Arranged at a plurality of positions aligned in the direction. The exciting coil 33b is formed of a coil wire wound around the stator core 33a, and a current flows through the exciting coil 33b with the relative rotation of the rotor 34 with respect to the stator 33. In other words, each of the stators 33 is disposed so as to surround the corresponding rotor 34 from the outside in the rotational radius direction, and the rotor 34 generates an electromotive force on the stator 33 by relative rotation of the rotor 34 with respect to the stator 33. It has a structure to give. Specifically, each rotor 34 according to this embodiment includes a plurality of permanent magnets 34a, and these permanent magnets 34a are circumferentially arranged on the outer peripheral surface of the input shaft 36 so as to rotate integrally with the input shaft 36. It is fixed at a plurality of positions arranged in a row.

  The structure of the power generation unit 30, particularly the structure in which a plurality of generators 32 </ b> A to 32 </ b> I are arranged in the axial direction around a common input shaft 36 driven by the engine 20 is a large number of generators 32 </ b> A in a small space. It is possible to drive them all together while accommodating ~ 32I and enabling generation of large electric power.

  The casing 35 plays an important role of supporting the input shaft 36 and collectively protecting the generators 32A to 32I. In addition, the casing 35 has a cooling channel that allows the coolant to flow through the casing 35. By providing, it is also possible to cool the generators 32A to 32I at once. Specifically, in the example shown in FIG. 4, a plurality of water-cooled pipes 39 are disposed so as to penetrate the peripheral wall 35 a of the casing 35 in the axial direction. As the cooling water flows through the water cooling pipe 39, each stator core 33a fixed to the casing 35 and the exciting coil 33b disposed around the stator core 33a are efficiently cooled.

  The air blowing section 40 includes “a plurality of cooling fans” according to the present invention and “a plurality of electric motors” for individually driving these cooling fans. Specifically, the air blowing unit 40 according to this embodiment includes nine electric fans 42A, 42B, 42C, 42D, 42E, 42F, 42G, 42H, and 42I, each including an electric motor 44 and a cooling fan 46. . The electric fans 42A, 42B, 42C, 42D, 42E, 42F, 42G, 42H and 42I correspond to the generators 32A, 32B, 32C, 32D, 32E, 32F, 32G, 32H and 32I, respectively. A cooling wind is formed by operating with the supply of electric power from the corresponding generator.

  The electric motor 44 included in each of the electric fans 42A to 42I has a motor output shaft 45, and rotates the motor output shaft 45 by electric power supplied from a corresponding generator among the generators 32A to 32I. Each cooling fan 46 has a shape that is fixed to the motor output shaft 45 so as to rotate integrally with the motor output shaft 45 and forms the cooling air by the rotation. Specifically, each of the cooling fans 46 includes a plurality of blades arranged around the rotation shaft, and the blades have a shape that forms cooling air flowing in a direction parallel to the rotation shaft.

  Thus, although each said electric fan 42A-42I integrates the cooling fan 46 and the electric motor 44 for the rotational drive, this invention is not limited to this. For example, in the present invention, a plurality of cooling fans and a plurality of electric motors for driving the cooling fans may be individually arranged, and a drive transmission mechanism may be interposed between the corresponding cooling fans and the electric motors.

  The plurality of electric fans 42 </ b> A to 42 </ b> I satisfy the condition that at least one electric fan is given to any one of the first to third coolers 11 to 13. Assigned to the first to third coolers 11 to 13. In this embodiment, among the nine electric fans 42A to 42I, three electric fans 42A, 42B and 42C are assigned to the first cooler 11, and the three electric fans 42D, 42E and 42F are the first ones. The two coolers 12 are allocated, and the three electric fans 42G, 42H, and 42I are allocated to the third cooler 13. Specifically, all the cooling air formed by the three electric fans 42A to 42C hits the first cooler 11, and all the cooling air formed by the three electric fans 42D to 42F is the second air. The arrangement positions of the electric fans 42A to 42I are set such that the cooling air formed by the three electric fans 42G to 42I hits the third cooler 13 when hitting the cooler 12.

  These electric fans 42 </ b> A to 42 </ b> I can be collectively supported as a single unit, for example, by fixing the electric motors 44 to a common frame. However, the present invention is not limited to such a configuration in which a plurality of cooling fans and electric motors are unitized as a single “blower”.

  In the present invention, the number of cooling fans assigned to each object to be cooled is not particularly limited. The number can be freely set based on the amount of cooling air required for cooling each object to be cooled. FIG. 5 is an example of a suitable arrangement when a large amount of air is required for the second cooler 12 compared to the first cooler 11, and conversely, a small amount of air is required for the third cooler 13. In the example shown in FIG. 5, four electric fans 42 </ b> D, 42 </ b> E, 42 </ b> F, and 42 </ b> I are assigned to the second cooler 12 among the nine electric fans 42 </ b> A to 42 </ b> I in the same manner as the example shown in FIG. Only two electric fans 42G and 42H are assigned to the cooler 13.

  In addition, the condition that “at least one cooling fan is given to the object to be cooled” is not limited to the condition that one whole electric fan is given to one object to be cooled, but a part of at least one electric fan. It is meant to include those that are only given. For example, the effective area of the corresponding cooling fan may be set according to the air volume required for cooling each cooled object. FIG. 6 is an example of an arrangement suitable for the case where a large amount of air is required for the first cooler 11 compared to the second cooler 12, and conversely, a small amount of air is required for the third cooler 13. A total of three electric fans 42J, 42K, and 42L are provided for cooling, and the electric fan 42K is disposed so as to straddle the first and second coolers 11 and 12, and the electric fan 42L includes the second and second electric fans 42L. It arrange | positions so that the 3rd coolers 12 and 13 may be straddled. In this arrangement, the first cooler 11 is given an effective area of about 1.5 electric fans, the second cooler 12 is given an effective area of about 1 electric fan, and the third cooler 13 is given an effective area. An effective area equivalent to about 0.5 electric fans is provided.

In addition, the sizes and air blowing capacities of the plurality of cooling fans according to the present invention need not all be the same.
For example, the same number of cooling fans may be assigned to each of the plurality of objects to be cooled, and a difference may be given to the size and blowing capacity of each cooling fan according to the air volume required for cooling the objects to be cooled.

  Further, the present invention can be effectively applied to a case where only a single object to be cooled is cooled, in which a plurality of cooling fans are required to cool the object to be cooled.

  The switch unit 50 shown in FIG. 2 is interposed between the power generation unit 30 and the air blower 40, and the electric fans 42A to 42I corresponding to the generators 32A to 32I included in the power generation unit 30 are provided. The power supply path for supplying electric power to each other is individually opened / closed, that is, conducted / interrupted. Specifically, in this embodiment, the generators 32 </ b> A to 32 </ b> I and the electric motors 44 of the electric fans 42 </ b> A to 42 </ b> I are individually connected via a plurality of power supply lines 54, while the switch unit 50. Includes nine contacts 52A, 52B, 52C, 52D, 52E, 52F, 52G, 52H and 52I, which are connected to the generators 32A, 32B, 32C, 32D, 32E, 32F, 32G, 32H and 32I and the electric fans 42A, 42B, 42C, 42D, 42E, 42F, 42G, 42H, and 42I are respectively interposed in the middle of nine feeding lines 54 that connect the electric motors 44. In the present embodiment, each of the contacts 52A to 52I is included in a single switch unit 50, and can be opened and closed independently of each other.

  The battery 60 takes in excess power generated by the power generation unit 30 and stores it, that is, stores it, and supplies power to the switch unit 50 and other electrical loads as necessary. To do. The battery 60 is not an essential element for the cooling device according to the present invention.

  The controller 70 is supplied to the first to third coolers 11 to 13 based on the temperatures of the first to third coolers 11 to 13 detected by the first to third temperature sensors 14 to 16. The temperature of the cooling air is adjusted, thereby controlling the temperature. Specifically, the controller 70 inputs an on / off command signal to the switch unit 50 in accordance with the temperatures detected by the first to third temperature sensors 14 to 16, so that the electric motors in the respective electric fans 42 </ b> A to 42 </ b> I. 44 is turned on / off.

  FIG. 7 shows the main functional configuration of the controller 70, and FIG. 8 shows its control operation. The controller 70 captures each of the detected temperatures T1 to T3 (step S0 in FIG. 8), and the first temperature shown in FIG. 7 as a component for performing control based on the detected temperatures T1 to T3. It has a determination unit 71, a second temperature determination unit 72, a third temperature determination unit 73, and a drive fan determination unit 74.

  The first temperature determination unit 71 determines which temperature region the first detected temperature T1 detected by the first temperature sensor 14, that is, the temperature of the fluid to be cooled in the first cooler 11, belongs to. (Step S1 in FIG. 8).

Low temperature region: a region in which the detected temperature is less than a preset temperature TL (for example, 40 ° C.) first intermediate region: a preset temperature TM (for example, 60 in which the detected temperature is equal to or higher than the preset temperature TL) Region below ° C) Second intermediate region: Region where the detected temperature is equal to or higher than the preset temperature TM and less than a preset temperature TH (for example, 70 ° C) High temperature region: The detected temperature is the preset temperature TH Similarly, the second temperature determination unit 72 determines that the second detected temperature T2 detected by the second temperature sensor 15, that is, the temperature of the fluid to be cooled in the second cooler 12, is in the temperature range. It is determined which one of them belongs (step S2 in FIG. 8), and the third temperature determination unit 73 applies the third detected temperature T3 detected by the third temperature sensor 16, that is, the third cooler 13. It is determined to which of the temperature regions the temperature of the fluid to be cooled belongs (step S3 in FIG. 8).

  The set temperatures TL, TM, and TH are relative, and specific values can be freely set according to the specifications of the object to be cooled. Further, the number of the set temperatures can be freely set, and two or less set temperatures (that is, a temperature region of 3 or less) may be set, or four or more set temperatures (that is, a temperature region of 5 or more). ) May be set.

  In this embodiment, common set temperatures TL, TM, and TH are given to the first to third detection temperatures T1 to T3 for the first to third coolers 11 to 13, respectively. Different set temperatures may be given depending on the object to be cooled.

  The driving fan determination unit 74 is based on the determination result of the first to third temperature determination units 71 to 73, that is, the determination result of which temperature region each of the first to third detection temperatures T1 to T3 belongs to. The electric fan to be driven is selected from the electric fans 42A to 42I. In other words, the on / off determination of the electric motor 44 in each of the electric fans 42A to 42I is performed individually. Specifically, the drive fan determination unit 74 stores the contents shown in the following table given in advance for the correspondence between the determined temperature range and the electric fan to be driven, and drives based on the stored contents. A power fan is selected (step S4 in FIG. 8). That is, for the electric motors 44 included in the respective electric fans 42A to 42I, it is determined whether or not the electric motors 44 should be operated.

  That is, for each of the first to third coolers 11 to 13, the drive fan determination unit 74 increases the number of electric fans to be operated among the electric fans assigned to the cooler as the detected temperature is higher. Specifically, among the three electric fans assigned to each of the coolers 11 to 13, so as to increase the electric fans to be driven in the order of the intermediate electric fan, the lower electric fan, and the upper electric fan, Select the electric fan. That is, the determination as to whether or not the electric power should be supplied to each motor 44, in other words, the determination of the opening / closing of the contacts 52A to 52I related to each motor 44, is performed individually.

  A specific example of the control operation performed by the controller 70 is shown below. FIG. 9 is a graph showing an example of the passage of time of the first to third detection temperatures T1 to T3, and shows an example of the control operation of the controller 70 accompanying the change of the first to third detection temperatures T1 to T3. It is a graph for. In this example, the first detection temperature T1 is the hydraulic oil temperature of the oil cooler, the second detection temperature T2 is the engine coolant temperature of the radiator, the third detection temperature T3 is the engine intake air temperature of the intercooler, and the set temperature TL is 40 ° C, set temperature TM is 60 ° C, and set temperature TH is 70 ° C.

  At each time t1 to t13 shown in FIG. 9, the controller 70 performs the following operation.

  Time t0: the detected temperatures T1 to T3 are all 40 ° C. or lower → all the electric fans 42A to 42I are stopped.

  Time t1: The third detected temperature (intercooler temperature) T3 rises to 40 ° C. → The intermediate-stage electric fan 42H is operated for the intercooler.

  Time t2: The first detected temperature (oil cooler temperature) T1 rises to 40 ° C. → The electric fan 42B at the intermediate stage is operated for the oil cooler.

  Time t3: The second detection temperature (radiator temperature) T2 rises to 40 ° C and at the same time the third detection temperature T3 rises to 60 ° C → the intermediate-stage electric fan 42E is activated for the radiator and the intercooler is The electric fan 42I is operated (two electric fans 42H and 42I are operated for the intercooler).

  Time t4: First detection temperature T1 rises to 60 ° C. → Lower electric fan 42C is operated for the oil cooler (two electric fans 42B and 42C are operated for the oil cooler).

  Time t5: Third detection temperature T3 rises to 70 ° C. → Upper electric fan 42G is operated for the intercooler (three electric fans 42G to 42I are operated for the intercooler).

  Time t6: The second detected temperature rises to 60 ° C. → The lower electric fan 42F is activated for the radiator (two electric fans 42E, 42F are activated for the radiator).

  Time t7: The first detected temperature T1 rises to 70 ° C. → The upper electric fan 42A is activated for the oil cooler (three electric fans 42A to 42C are activated for the oil cooler).

  Time t8: The second detected temperature T2 rises to 70 ° C. → The upper electric fan 42D is activated for the radiator (three electric fans 42D to 42F are activated for the radiator).

  Time t9: The first to third detection temperatures T1 to T3 are all lowered to 70 ° C. → the upper electric fans 42A, 42D and 42G are stopped.

  Time t10: Third detected temperature T3 drops to 60 ° C. → Lower electric fan 42I is stopped for the intercooler.

  Time t11: At the same time the first detection temperature T1 drops to 60 ° C., the third detection temperature T3 drops to 40 ° C. → The lower electric fan 42C for the oil cooler is stopped and the intermediate electric fan 42H for the intercooler is turned off. Stop.

  Time t12: At the same time the second detection temperature T2 drops to 60 ° C., the first detection temperature T1 drops to 40 ° C. → The lower electric fan 42F is stopped for the radiator and the intermediate electric fan 42B is stopped for the oil cooler. Let

  Time t13: The second detected temperature T2 drops to 40 ° C. → The intermediate-stage electric fan 42E is stopped for the radiator.

  In this control example, a set temperature for determining the start of driving of the electric fan (increase in the number of electric fans to be driven) and a set temperature for determining stop of driving of the electric fan (a decrease in the number of electric fans to be driven). Are the same, but hysteresis may be provided between them for stabilization of control.

  In the embodiment described above, the plurality of generators 32A to 32I included in the power generation unit 30 and the plurality of motors 44 constituting each of the electric fans 42A to 42I correspond one-to-one, and the corresponding generators Since the contacts 52A to 52I are respectively interposed between the motor and the motor, the controller 70 can appropriately set the amount of cooling air to each of the coolers 11 to 13 simply by switching the contacts 52A to 52I. The temperature of the cooling 11 to 13 can be controlled.

  However, the cooling device according to the present invention is not limited to this embodiment. For example, in the present invention, the number of the plurality of generators may be different from the number of the plurality of electric motors. In this case, a control device including an inverter or the like may be interposed between the plurality of generators and the plurality of motors, and supply of the power generated by the plurality of generators to the plurality of motors may be controlled. . Alternatively, even when there is a one-to-one correspondence between a plurality of generators and a plurality of motors, the inverter or the like may be interposed between the corresponding generators and motors.

6 Engine room 11 1st cooler (cooled body)
12 Second cooler (object to be cooled)
13 Third cooler (cooled object)
14 First temperature sensor (temperature detector)
15 Second temperature sensor (temperature detector)
16 Third temperature sensor (temperature detector)
20 Engine 22 Engine output shaft 30 Power generation unit 32A to 32I Generator 33 Stator (stator)
34 Rotor
35 Casing 36 Input shaft 37 Bearing 39 Water-cooled piping (cooling flow path)
40 Blower 42A-42I Electric Fan 44 Electric Motor 46 Cooling Fan 50 Switch Unit 52A-52I Contact 54 Feed Line 70 Controller (Temperature Control Unit)
71 First temperature determination unit 72 Second temperature determination unit 73 Third temperature determination unit 74 Drive fan determination unit

Claims (10)

An apparatus for cooling at least one object to be cooled provided in a construction machine,
A plurality of cooling fans that form cooling air for cooling the cooled object by being driven to rotate;
A plurality of electric motors that respectively rotate and drive these cooling fans, an engine that generates and outputs power,
A power generation unit that is driven by the power output by the engine and thereby generates electric power to be supplied to each electric motor. The power generation unit includes an input shaft that is rotationally driven by the power of the engine; A cooling device for a construction machine, comprising: a plurality of generators that are arranged along the axial direction of an input shaft and that individually generate electric power by rotation of the input shaft.   The cooling device for a construction machine according to claim 1, wherein the engine has an output shaft for outputting the power, and the power generation unit is arranged so that an input shaft of the power generation unit is parallel to the output shaft. Arranged cooling equipment for construction machinery.   The construction machine cooling device according to claim 1, wherein the power generation unit further includes a casing that rotatably supports the input shaft and stores the generators collectively. apparatus.   The construction machine cooling device according to claim 3, wherein each of the generators includes a stator and a rotor, and generates electric power by relative rotation of the rotor with respect to the stator. The rotor of the machine is fixed on the outer peripheral surface of the input shaft so as to be aligned along the axial direction of the input shaft, and the stator of each generator surrounds the rotor from the outside in the rotational radius direction. A cooling device for a construction machine, which is fixed on an inner surface of the casing.   5. The cooling device for a construction machine according to claim 4, wherein a cooling channel that allows a cooling medium to flow is formed inside the casing.   The construction machine cooling device according to any one of claims 1 to 5, wherein the power generation unit includes, as the plurality of generators, generators corresponding to the plurality of electric motors, respectively, A cooling device for a construction machine, which is individually electrically connected to the electric motor so that electric power can be supplied to the electric motor corresponding to the generator.   The cooling device for a construction machine according to claim 6, wherein the cooling device further includes a plurality of contacts that individually open and close power supply paths connecting the plurality of electric motors and the plurality of generators corresponding thereto. , Cooling equipment for construction machinery.   8. The cooling device for a construction machine according to claim 7, wherein the cooling device detects a temperature of the at least one object to be cooled, and each contact point based on a temperature detected by the temperature detection unit. And a temperature control unit that switches between opening and closing of the construction machine.   The cooling device for a construction machine according to claim 8, wherein the cooling fans are arranged so that the cooling air formed by the plurality of cooling fans hits the cooled body with respect to the cooled body. The temperature control unit determines a cooling fan to be operated among the plurality of cooling fans given to the cooled body based on the temperature detected for the cooled body, and operates only the cooling fan. A construction machine cooling device that switches between opening and closing of the contacts.   The construction machine cooling device according to claim 8 or 9, wherein the at least one object to be cooled includes a plurality of objects to be cooled, and the temperature detection unit detects a temperature of each object to be cooled. A detector, and at least one of the plurality of cooling fans is provided to each object to be cooled, and the temperature control unit opens and closes each contact based on the temperature detected by each temperature detector. A cooling device for construction machinery that performs switching.

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