JP2015004187A - Pipe cooling system in engine room of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe cooling system in an engine room of a construction machine, which can cool a pipe in the engine room while restraining the cost.SOLUTION: A pipe cooling system 20 for cooling a pipe 19 is provided in an engine room ER. The pipe cooling system 20 comprises an existing fan 13 arranged to face an existing radiator 14 for cooling an engine 11, an existing shroud 15 arranged between the fan 13 and the radiator 14 so as to surround the fan 13, and a newly-added cooling pipe 21. The cooling pipe 21 is arranged so as to cover the pipe 19. One end of the cooling pipe 21 is connected to an opening for connection 15a provided in the shroud 15 and the other end of it is connected to an opening for connection 101a provided in a building cover 101.

Description

  The present invention relates to a cooling device used for cooling piping in an engine room of a construction machine such as a hydraulic excavator.

  In an engine room of a construction machine such as a hydraulic excavator, an engine, a hydraulic pump, a radiator for cooling the engine, a fan arranged opposite to the radiator, and a shroud arranged so as to surround the fan between the fan and the radiator Etc. are arranged. Furthermore, piping such as fuel piping, urea water piping, and electrical wiring is arranged in the engine room.

  On the other hand, when the construction machine is driven in a high-temperature environment such as under hot weather, the interior of the engine room becomes hot. In this case, the temperature of the fluid passing through the pipe rises due to the pipe being heated by the heat in the engine room, which may hinder the operation of the construction machine.

  Therefore, a method is adopted in which an opening is provided in the building cover forming the engine room, and the piping is cooled by introducing outside air into the engine room through this opening to lower the temperature in the engine room.

  However, considering the protection of equipment such as an engine, the size of the opening is limited. Therefore, even if the opening is provided in the building cover, the piping may not be sufficiently cooled.

  Thus, for example, a method has been proposed in which an air flow source (fan) is newly provided in the engine room and the piping is cooled using the air flow source (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-338036

  However, when a new air flow source is provided in the engine room, there is a problem that the cost is significantly increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a piping cooling device in an engine room of a construction machine that can cool the piping in the engine room at a reduced cost. .

  As a result of diligent research, the present inventors have employed a pipe cooling device in the engine room of a construction machine as described below in order to solve the above-described problems.

The piping cooling device for the engine room of the construction machine according to the present invention,
A pipe cooling device in the engine room of a construction machine used for cooling the pipe in the engine room formed by the building cover,
An existing fan disposed opposite to an existing radiator for cooling an engine in the engine room, an existing shroud disposed so as to surround the fan between the fan and the radiator, and the piping. A cooling pipe arranged to cover,
The cooling pipe has one end connected to a connection opening provided in the shroud, and the other end connected to a connection opening provided in the building cover.

  In the pipe cooling device in the engine room of the construction machine of the present invention, a cooling pipe covering the pipe is newly added, and both ends of the cooling pipe are connected to the shroud connection opening and the building cover connection opening. Connected. As a result, when the fan is driven, outside air enters the cooling pipe from the connection opening of the building cover and flows toward the shroud. The pipe is cooled by outside air flowing through the cooling pipe. Therefore, the pipe cooling device in the engine room of the construction machine according to the present invention can cool the pipe in the engine room using an existing fan, so that a new air source is not required and the cost can be reduced. . Therefore, the piping cooling device for the engine room of the construction machine according to the present invention can cool the piping in the engine room at a reduced cost.

1 is a left side view of a hydraulic excavator showing an embodiment of the present invention. It is a schematic diagram of the upper surface of the engine room of the embodiment. It is a schematic diagram of the side surface of the engine room of the embodiment. It is sectional drawing of the piping for cooling of the embodiment. It is a figure which shows the structure of the urea SCR system of the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a left side view of a hydraulic excavator 1 showing an embodiment of the present invention. The hydraulic excavator 1 includes a traveling body 2, a revolving body 3 provided on the traveling body 2 so as to be able to swivel, and a work device 4 for performing excavation work and the like provided on the front side of the revolving body 3.

  On the swivel body 3, a cab 5 is provided on the front side, and a machine room 6 is provided on the rear side. A counterweight 7 is provided on the rear side of the machine room 6.

  The machine room 6 is provided with an engine room ER as shown in FIGS. The engine room ER is formed by a building cover 101 provided on the revolving structure 3.

  First, a basic configuration in the engine room ER will be described. An engine 11, a hydraulic pump 12 connected to the engine 11, and a fan 13 are provided in the engine room ER.

  Further, a radiator 14 that cools the engine 11 is disposed in the engine room ER so as to face the fan 13. A shroud 15 is disposed between the radiator 14 and the fan 13 so as to cover the fan 13. A battery 16 is provided on the side of the radiator 14 opposite to the fan 13.

  On the upper surface of the building cover 101, although not shown, an intake port is formed at a position opposite to the fan 13 of the radiator 14.

  A muffler 17 is attached to the exhaust side of the engine 11. An exhaust pipe 18 is attached to the muffler 17 so as to protrude from the upper surface of the building cover 101. Further, although not shown, a discharge port is formed in the vicinity of the exhaust pipe 18 on the upper surface of the building cover 101.

  Next, basic operations in the engine room ER will be described. When the fan 13 is driven, the outside air A flows into the engine room ER from the intake port and passes through the radiator 14. The radiator 14 uses the outside air A to cool the cooling water of the engine 11 circulating with the engine 11. The engine 11 is cooled by this cooling water.

  Further, since the outside air A flowing in from the intake port is smoothly guided to the radiator 14 by the shroud 15, a large amount of outside air A can be passed through the radiator 14, and the engine 11 can be efficiently cooled. Yes.

  Further, the outside air A that has passed through the radiator 14 rises and is sent to the engine 11 side, and is discharged out of the engine room ER from the discharge port.

  Next, the configuration according to the present invention in the engine room ER will be described. A piping 19 is routed in the engine room ER. The piping 19 includes fuel piping, urea water piping, electrical wiring, and the like.

  Further, a pipe cooling device 20 is provided in the engine room ER for cooling the pipe 19. The pipe cooling device 20 includes the existing fan 13 and the existing shroud 15 described above, a newly added cooling pipe 21 and a control valve 22.

  The cooling pipe 21 is disposed so as to cover the pipe 19. One end side of the cooling pipe 21 is connected to a connection opening 15 a provided in the shroud 15. The other end of the cooling pipe 21 is connected to a connection opening 101 a provided in the building cover 101. The control valve 22 opens and closes the inside of the cooling pipe 21.

  Next, the operation of the pipe cooling device 20 will be described. When the fan 13 is driven, the outside air A enters the cooling pipe 21 from the connection opening 101 a of the building cover 101 and flows toward the shroud 15. The pipe 19 is cooled by the outside air A flowing through the cooling pipe 21.

  As described above, in the pipe cooling device 20 of the present embodiment, the pipe 19 in the engine room ER can be cooled using the existing fan 13 (air flow source). Therefore, since a new air current source is not required, the cost can be reduced. Therefore, the pipe cooling device 20 of the present embodiment can cool the pipe 19 in the engine room ER at a reduced cost.

  Further, the pipe cooling device 20 of the present embodiment closes the inside of the cooling pipe 21 by the control valve 22 so that the outside air A does not flow when the hydraulic excavator 1 is operated in a cold region. By doing in this way, even when the temperature of the outside air A is low, the temperature of the fluid in the pipe 19 does not drop too much, and there is no possibility of adversely affecting the operation of the excavator 1. Therefore, the pipe cooling device 20 according to the present embodiment can cool the pipe 19 according to the temperature of the outside air A, so that convenience can be improved.

  The control valve 22 may be opened or closed manually or automatically. When the control valve 22 is automatically opened and closed, the temperature of the pipe 19 may be detected by a sensor or the like, and the control valve 22 may be opened and closed based on the detected temperature.

  As mentioned above, although embodiment concerning this invention was illustrated, said embodiment does not limit the content of this invention. Various modifications can be made without departing from the scope of the claims of the present invention.

  For example, the material of the cooling pipe 21 may be a bellows pipe or the like as long as it has negative pressure durability and heat resistance in addition to the steel pipe. Further, the layout of the cooling pipe 21 is not particularly limited. The cooling pipe 21 may be installed together with the piping 19 or may be retrofitted. Further, any space in the engine room ER may be used as long as there is a space for the cooling pipe 21. For example, as shown in FIG. 3, the cooling pipe 21 may be extended from the lower side of the engine 11 to the lower side of the hydraulic pump 12.

  The cross-sectional shape of the cooling pipe 21 is not particularly limited as shown in FIG. The number of the pipes 19 covered with the cooling pipe 21 is not particularly limited. Moreover, the range (cooling range) which covers the piping 19 of the piping 21 for cooling is not specifically limited.

  Although not shown, the connection opening 101a of the building cover 101 may be attached by covering it with a mesh material (net material). Since the mesh material captures dust in the outside air A when the outside air A enters the cooling pipe 21, the inside of the cooling pipe 21 can be prevented from being clogged with dust. Therefore, it becomes possible to flow the outside air A smoothly through the cooling pipe 21, and the cooling efficiency of the pipe 19 can be increased.

  Further, as the pipe 19 to which the pipe cooling device 20 of the present embodiment is applied, a fuel pipe, a urea water pipe, an electric wiring, and the like are given. The urea water pipe is used in the urea SCR system 201 shown in FIG.

  As is well known, the urea SCR system 201 is provided in an engine room ER of a vehicle such as a construction machine on which a diesel engine is mounted, and purifies the exhaust gas by reducing nitrogen oxides in the exhaust gas.

  The urea SCR system 201 includes a urea SCR system main body 202 and a urea water adding device 203 that adds urea water to the urea SCR system main body 202.

  The urea SCR system main body 202 includes a front-stage oxidation catalyst 221, an SCR catalyst 222, and a rear-stage oxidation catalyst 223 that are sequentially arranged from the upstream side in the exhaust passage 11 a of the engine 11.

  The urea water addition device 203 includes a urea water tank 231, a urea water pump 232 connected to the urea water tank 231, and a urea water injection device 233 connected to the urea water pump 232. The injection position of the urea water injection device 233 is set between the upstream oxidation catalyst 221 and the SCR catalyst 222.

  A method for purifying exhaust gas by the urea SCR system 201 will be described. The urea water pump 232 sucks urea water from the urea water tank 231 and supplies it to the urea water injection device 233. The urea water injection device 233 injects the urea water supplied from the urea water pump 232 between the pre-stage oxidation catalyst 221 and the SCR catalyst 222.

  The pre-stage oxidation catalyst 221 oxidizes hydrocarbons and carbon monoxide in the exhaust gas of the engine 11 to harmless carbon dioxide and water. The urea water injected from the urea water injection device 233 is added to the nitrogen oxides in the exhaust gas that has passed through the pre-stage oxidation catalyst 221. The urea water is hydrolyzed by the heat of the exhaust gas to generate ammonia. This ammonia reduces nitrogen oxides to harmless nitrogen in the SCR catalyst 222. Excess ammonia is oxidized by the post-stage oxidation catalyst 223 into harmless nitrogen and water.

  In the urea SCR system 201 described above, the urea water pipe to which the pipe cooling device 20 of the present embodiment is applied is the urea water pipe 19 that connects the urea water pump 232 and the urea water injection device 233. The reason is as follows.

  While the urea water decomposes at about 70 ° C., the temperature in the engine room ER is usually 80 ° C. to 90 ° C. Further, the length of the urea water pipe 19 connecting the urea water pump 232 and the urea water injection device 233 is generally long. Therefore, the urea water passing through the urea water pipe 19 may be decomposed under the influence of heat in the engine room ER.

  Therefore, in the pipe cooling device 20 of the present embodiment, the urea water pipe 19 is covered with the cooling pipe 21 and cooled, thereby suppressing an increase in the temperature of the urea water passing through the urea water pipe 19 and preventing decomposition. be able to. Therefore, the pipe cooling device 20 of the present embodiment can suppress the reduction in exhaust gas purification processing efficiency by reducing the cost even when the urea water pipe 19 is cooled.

1 Excavator (construction machine)
DESCRIPTION OF SYMBOLS 11 Engine 13 Fan 14 Radiator 15 Shroud 15a Shroud connection opening 19 Pipe 20 Pipe cooling device 21 Cooling pipe 22 Control valve 101 Building cover 101a Building cover connection opening 201 Urea SCR system 232 Urea water pump 233 Urea water Injector ER Engine room

Claims (3)

A pipe cooling device in the engine room of a construction machine used for cooling the pipe in the engine room formed by the building cover,
An existing fan disposed opposite to an existing radiator for cooling an engine in the engine room, an existing shroud disposed so as to surround the fan between the fan and the radiator, and the piping. A cooling pipe arranged to cover,
The cooling pipe has one end connected to a connection opening provided in the shroud and the other end connected to a connection opening provided in the building cover. Piping cooling device in the room. In the piping cooling device in the engine room of the construction machine according to claim 1,
A pipe cooling device in an engine room of a construction machine, comprising a control valve for opening and closing the inside of the cooling pipe. In the piping cooling device in the engine room of the construction machine according to claim 1 or 2,
The pipe is a urea water pipe that connects a urea water pump and a urea water injection device constituting the urea SCR system, and the cooling pipe covers the urea water pipe. Pipe cooling system in the engine room of the machine.