JP6103639B2 - Arrangement structure of piping for reducing agent in construction machinery - Google Patents

Description

  The present invention relates to a technical field of an arrangement structure of a reducing agent pipe extending from a reducing agent tank to an exhaust gas purifying device in a construction machine including an exhaust gas purifying device and a reducing agent tank.

Generally, diesel engines are widely used as power sources in construction machines such as hydraulic excavators. However, exhaust gas discharged from diesel engines contains a large amount of nitrogen oxides (NOx). Various exhaust gas purification apparatuses for removing and purifying nitrogen oxides therein have been put into practical use.
As such an exhaust gas purification device, a device in which a reducing agent such as urea water is injected into the exhaust passage of a diesel engine to reduce nitrogen oxides is known. When using a reducing agent, the reducing agent is stored in a reducing agent tank mounted on a construction machine, reaches the injection device through the reducing agent pipe from the reducing agent tank, and is injected into the exhaust passage by the injection device. It is comprised so that.
By the way, the exhaust gas purifying apparatus as described above is usually disposed in the engine room because it is connected to the exhaust path of the engine. On the other hand, it is necessary to replenish the reductant tank appropriately. However, it is desirable to replenish the reductant at the same timing as the fuel replenishment. It is known that a reductant tank is disposed and a reductant pipe extending from the reductant tank to the exhaust gas purification device is disposed along a fuel tank or a hydraulic oil tank adjacent to the fuel tank. (For example, refer to Patent Document 1).

JP 2012-207552 A

  However, when the reducing agent such as urea water becomes a high temperature before being injected into the exhaust passage, it may be thermally decomposed and may not perform its function. If the temperature of the urea water supplied to the injection device is high, it may crystallize before being mixed with exhaust gas after injection, and an appropriate reduction reaction may not be obtained. On the other hand, since the reducing agent injection device is connected to the exhaust passage, it tends to be hot. For this reason, it is necessary to consider that the temperature of a reducing agent does not rise as much as possible until it reaches an injection device. However, when the reducing agent pipe is arranged along the fuel tank or the hydraulic oil tank as in Patent Document 1, the fuel tank is returned from the injection device, and the hydraulic oil tank is supplied from the actuator. Since it becomes high temperature by return oil, there exists a possibility that the temperature of a reducing agent may rise in response to the heat from these fuel tanks or hydraulic oil tanks, and here is a problem to be solved by the present invention.

The present invention has been created for the purpose of solving these problems in view of the above circumstances, and the invention of claim 1 includes a diesel engine, an oil tank for storing fuel and hydraulic oil, In a construction machine including an exhaust gas purifying device provided in an exhaust passage of the diesel engine and a reducing agent tank for storing a reducing agent supplied to the exhaust gas purifying device, the reducing agent tank leads to the exhaust gas purifying device. When arranging the reducing agent piping along the oil tank, the piping cover forming the reducing agent piping is extended from the outer wall surface of the oil tank or the outer cover covering the outer wall surface. And a reducing agent pipe in a construction machine, wherein the reducing agent pipe is held on the pipe cover at a distance from the oil tank.
The invention of claim 2 is the arrangement structure of the reducing agent pipe in the construction machine according to claim 1, wherein the pipe cover is provided with a slit for ventilation.
The invention according to claim 3, in claim 1 or 2, the construction machine, the cooling device is mounted comprising a radiator and an oil cooler, the pipe cover, a pipe for the reducing agent from the exhaust air from the cooling device It is the arrangement | positioning structure of the piping for reducing agents in the construction machine characterized by providing the wind-shielding wall for shielding.
A fourth aspect of the present invention is the construction machine according to any one of the first to third aspects, wherein the piping cover is formed by extending an outer wall surface of the oil tank or an outer cover that covers the outer wall surface. 2 is a structure for arranging a reducing agent pipe in FIG.

According to the first aspect of the present invention, the reducing agent pipe can be disposed without being in contact with the oil tank, and the temperature of the reducing agent due to heat from the oil tank is reliably suppressed. it can.
By setting it as invention of Claim 2, it can prevent more reliably that a reducing agent will rise in temperature.
By setting it as invention of Claim 3, piping for reducing agents can be shielded from the exhaust air of a cooling device with high temperature.
The invention of claim 4 is advantageous in that it is excellent in appearance and does not require a separate member for the piping cover.

It is a partially notched top view of an upper revolving structure. It is a perspective view of the airframe right side part. (A) is a perspective view which shows the arrangement | positioning state of the piping for urea water, (B) is sectional drawing which shows the arrangement | positioning state of the piping for urea water. (A) is sectional drawing which shows the arrangement | positioning state of the piping for urea water in 2nd embodiment, (B) is sectional drawing which shows the arrangement | positioning state of the piping for urea water in 3rd embodiment, (C ) Is a cross-sectional view showing the arrangement of urea water pipes in the fourth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes an upper swing body of a hydraulic excavator which is an example of a construction machine. The upper swing body 1 is equipped with a front work machine 2 for performing various operations such as excavation and a driver's seat. Various member devices such as a cab 3 arranged, a fuel tank 4 in which fuel is stored, a hydraulic oil tank 5 in which hydraulic oil is stored, a diesel engine (hereinafter also simply referred to as an engine) 6 serving as a power source, and a counterweight 7 The basic configuration such as is mounted as before.

  The fuel tank 4 and the hydraulic oil tank 5 are disposed on the right side of the upper swing body 1 and adjacent to each other in the front-rear direction with the fuel tank 4 positioned on the front side and the hydraulic oil tank 5 positioned on the rear side. . The outer wall surfaces 4a and 5a (right side surface in the present embodiment) of the fuel tank 4 and the hydraulic oil tank 5 are covered with a thin plate-like outer cover 8, and welding marks and the like of the outer wall surfaces 4a and 5a are visually observed from the outside. Not to be. A storage chamber (storage box) 9 is provided in front of the fuel tank 4, and a urea water tank (corresponding to a reducing agent tank of the present invention) 10 described later is stored in the storage chamber 9. Yes. The fuel tank 4 and the hydraulic oil tank 5 correspond to an oil tank for storing the fuel and hydraulic oil of the present invention.

  On the other hand, the engine 6 is disposed at a substantially central portion in the left-right direction of the engine room 11 provided at the rear of the machine body. Furthermore, in the engine room 11, various devices such as a hydraulic pump 12 driven by the engine 6, a cooling device 13 such as a radiator and an oil cooler, an exhaust gas purification device 14 and a muffler 15 described later are disposed. In the present embodiment, the engine 6 is arranged in a state of being partitioned from the hydraulic pump 12 and the cooling device 13 by a firewall (fire wall).

  The exhaust gas purifying device 14 is for removing and purifying nitrogen oxides in the exhaust gas discharged from the engine 6, and is connected to a midway part of the exhaust pipe 16 serving as an exhaust gas exhaust path. The exhaust gas discharged from the engine 6 is purified by the exhaust gas purification device 14 and then discharged to the outside through the muffler 15.

  Here, in the present embodiment, the exhaust gas purification device 14 is obtained by injecting urea water (corresponding to the reducing agent of the present invention) from the urea water injection device 14a into the exhaust passage and hydrolyzing it at a high temperature. A urea SCR system configured to reduce nitrogen oxide in exhaust gas with the generated ammonia and decompose it into nitrogen and water is employed. In addition, although not shown, the exhaust gas purification device 14 is also provided with a PM collection device (DPF) having a filter for collecting particulate matter (PM).

  On the other hand, 17 is a urea water pipe (corresponding to the reducing agent pipe of the present invention) from the urea water tank 10 to the urea water injection device 14a of the exhaust gas purification device 14, and the urea water pipe 17 is: The engine room 11 is drawn from the storage chamber 9 in the front part of the machine body in which the urea water tank 10 is stored, led to the rear part of the machine body along the fuel tank 4 and the hydraulic oil tank 5, and the exhaust gas purification device 14 is disposed. It is piped to reach.

  Thus, the urea water pipe 17 is disposed along the fuel tank 4 and the hydraulic oil tank 5. In this case, the outer wall surfaces (right side surfaces) of the fuel tank 4 and the hydraulic oil tank 5 are arranged. The front cover of the outer cover 8 that covers 4a and 5a extends forward from the front surface 4b of the fuel tank 4, and the upper end of the outer cover 8 covers the upper surfaces 4c and 5c of the fuel tank 4 and the hydraulic oil tank 5. A pipe cover 18 serving as an arrangement path for the urea water pipe 17 is formed by extending portions of the outer cover 8.

  The piping cover 18 includes a front piping cover portion 18 </ b> X serving as a urea water piping 17 arrangement path on the front side of the fuel tank 4, and a urea water piping 17 arrangement path above the fuel tank 4 and the hydraulic oil tank 5. The upper piping cover portion 18Y is formed in a series, and the front piping cover portion 18X is formed to extend forward from the front end portion of the outer cover 8 and is flush with the outer cover 8. An extended side 18a, and a bent side 18b that is bent from the front end of the extended side 18a and is parallel to the front surface 4b of the fuel tank 4, with an upper pipe cover. The portion 18Y extends upward from the upper end portion of the outer cover 8 and is formed to extend from the upper end of the extending side 18a and the extended side 18a that is flush with the outer cover 8, and to form a fuel tank. 4 and the upper surface of the hydraulic oil tank 5 c, 5c and a bent side 18b that is parallel to each other, and the front side, the extended side 18a of the upper side pipe cover portions 18X and 18Y, or the bent side 18b includes a pipe 17 for urea water. A plurality of pipe holders 19 such as clips for holding the bolts are secured at appropriate intervals. The urea water pipe 17 is held by the pipe holder 19 so as to be spaced from the front surface 4 b of the fuel tank 4 and the upper surfaces 4 c and 5 c of the fuel tank 4 and the hydraulic oil tank 5. 18 (front side pipe cover part 18X and upper side pipe cover part 18Y) is arranged along the inner side surface of the bent side 18b, whereby the urea water pipe 17 is operated in the fuel tank 4 and the operation. It is configured so that piping can be performed without contacting the oil tank 5.

  Further, a plurality of slits 18c for ventilation are provided in the pipe cover 18 with a predetermined interval. As a result, the urea water pipe 17 is cooled by the outside air, and heat can be prevented from being trapped inside the pipe cover 18, and the temperature of the urea water in the urea water pipe 17 rises. It can be prevented.

  In the present embodiment configured as described, the hydraulic excavator includes a diesel engine 6 as a power source, a fuel tank 4 in which fuel is stored, a hydraulic oil tank 5 in which hydraulic oil is stored, and an exhaust path of the diesel engine 6. An exhaust gas purification device 14 provided, a urea water tank 10 for storing urea water supplied to the exhaust gas purification device 14 and the like are mounted, and a urea water pipe 17 extending from the urea water tank 10 to the exhaust gas purification device 14 includes: Although arranged along the fuel tank 4 and the hydraulic oil tank 5, in this case, the outer cover 8 covering the outer wall surfaces 4 a and 5 a of the fuel tank 4 and the hydraulic oil tank 5 is provided with a urea water pipe 17. A pipe cover 18 serving as an arrangement path is extended and the urea water pipe 17 is spaced from the fuel tank 4 and the hydraulic oil tank 5 in the pipe cover 18. It will be held.

  As a result, the urea water pipe 17 is arranged without being in contact with the fuel tank 4 and the hydraulic oil tank 5 while the urea water pipe 17 is arranged along the fuel tank 4 and the hydraulic oil tank 5. As a result, it is possible to reliably suppress the temperature of the urea water in the urea water pipe 17 from rising due to heat from the fuel tank 4 and the hydraulic oil tank 5.

  Moreover, the pipe cover 18 that holds the urea water pipe 17 is formed to extend from the outer cover 8 that covers the outer wall surfaces 4 a and 5 a of the fuel tank 4 and the hydraulic oil tank 5. And is excellent in appearance, and there is an advantage that a separate member for the piping cover 18 is not required.

  Further, the slit 18c for ventilation is formed in the pipe cover 18, so that the urea water pipe 17 is cooled by the outside air, and heat can be prevented from being accumulated inside the pipe cover 18, It is possible to more reliably prevent the temperature of the urea water in the urea water pipe 17 from rising.

Needless to say, the present invention is not limited to the above embodiment, and in the above embodiment, the reducing agent pipe (urea water pipe) is disposed along the fuel tank and the hydraulic oil tank. However, it is needless to say that the present invention can be implemented even when it is disposed along any one of the oil tanks (fuel tank or hydraulic oil tank).
Further, in the above embodiment, the pipe cover is configured to be a reducing agent pipe arrangement path on the front side and the upper side of the oil tank, but the reducing agent is provided on either the front side or the upper side of the oil tank. It may be an arrangement path for the pipe for use, or may be an arrangement path for the reducing agent pipe on the rear side of the oil tank.
In the above embodiment, the piping cover is formed by extending the outer cover that covers the outer wall surface of the oil tank (fuel tank or hydraulic oil tank). The second cover shown in FIG. As in the embodiment, the pipe cover 21 may be formed by extending the outer wall surface 20 a of the oil tank 20. In FIG. 4A, 17 is a urea water pipe, 19 is a pipe holder, 21a and 21b are extended sides and bent sides constituting the pipe cover 21, and 22 is an outer cover.
Further, as in the third embodiment shown in FIG. 4B, the pipe cover 23 is formed of a separate member from the outer cover 24 (or the outer wall surface 25a of the oil tank 25) and is made of the separate member. The piping cover 23 is extended from the outer cover 24 (or the outer wall surface 25a of the oil tank 25) by fixing it to the outer cover 24 (or the outer wall surface 25a of the oil tank 25) using fixing means 26 such as bolts. It may be configured. In FIG. 4B, 17 is a urea water pipe, 19 is a pipe holder, and 23 a and 23 b are extended sides and bent sides constituting the pipe cover 23.
Further, depending on the arrangement of various member devices in the construction machine, exhaust air discharged from a cooling device such as a radiator or an oil cooler may be discharged to the reducing agent pipe (urea water pipe) arranged along the oil tank. Sometimes sprayed from the inside. In such a case, as in the fourth embodiment shown in FIG. 4C, the windshield wall 27c for shielding the urea water pipe 17 from the exhaust air from the cooling device is provided on the pipe cover 27. By providing this, it is possible to shield the urea water pipe 17 from exhaust air having a high temperature. In FIG. 4C, 19 is a pipe holder, 27a and 27b are extended sides and bent sides constituting the pipe cover 27, 28 is an outer cover, and 29 is an oil tank.

  INDUSTRIAL APPLICABILITY The present invention can be used in a construction machine including an exhaust gas purification device and a reducing agent tank when a reducing agent pipe extending from the reducing agent tank to the exhaust gas purification device is disposed.

4 Fuel tank 4a Outer wall surface 5 Hydraulic oil tank 5a Outer wall surface 6 Diesel engine 8 Outer cover 10 Urea water tank 13 Cooling device 14 Exhaust gas purification device 17 Urea water piping 18 Piping cover 18c Slit

Claims (4)

  A diesel engine, an oil tank for storing fuel and hydraulic oil, an exhaust gas purification device provided in the exhaust passage of the diesel engine, and a reducing agent tank for storing a reducing agent supplied to the exhaust gas purification device are mounted. In the construction machine, when the reducing agent pipe extending from the reducing agent tank to the exhaust gas purification device is arranged along the oil tank, a pipe cover that forms an arrangement path of the reducing agent pipe is provided with an oil A reducing agent in a construction machine, wherein the reducing agent pipe is provided in a state extending from an outer wall surface of the tank or an outer cover that covers the outer wall surface, and the pipe for reducing agent is held in the pipe cover at a distance from the oil tank. Piping arrangement structure.   2. The arrangement structure of a reducing agent pipe in a construction machine according to claim 1, wherein a slit for ventilation is provided in the pipe cover. According to claim 1 or 2, the construction machine, the cooling device comprising a radiator and oil cooler are mounted, the pipe cover, Saegikazekabe for shielding the piping reducing agent from the exhaust air from the cooling device An arrangement structure of a reducing agent pipe in a construction machine.   4. The piping of the reducing agent pipe in a construction machine according to claim 1, wherein the piping cover is formed by extending an outer wall surface of the oil tank or an outer cover covering the outer wall surface. Construction structure.

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