JP2015161260A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction machine for suppressing the temperature rise of a reductant tank, thus suppressing the influences on reductant.SOLUTION: The construction machine comprises: an exhaust emission control device installed in an exhaust flow path of an engine, and including a reduction catalyst using reductant for reducing nitrogen oxide to be eliminated from exhaust gas, and a reductant injection valve for injecting the reductant into the exhaust flow path; a carrier; a revolving superstructure provided on the upper part of the carrier in a revolvable manner; and a working device provided on the revolving superstructure. In the revolving superstructure, a reductant tank for storing the reductant to be injected from the reductant injection valve and a working oil tank for storing working oil to be used for a hydraulic circuit to drive the working device are arranged neighboring each other. The reductant tank is covered with a tank cover having an air inlet and an air outlet located above the air inlet. On the tank cover, a heat insulation member is provided for suppressing the propagation of heat from the working oil tank.

Description

  The present invention relates to a construction machine including a reducing agent tank.

  A construction machine including an exhaust gas purification device that removes nitrogen oxides in exhaust gas is known (see Patent Document 1). As this type of exhaust gas purifying apparatus, there is an apparatus in which a reducing catalyst is arranged in an exhaust system of an engine and a reducing agent is supplied from a reducing agent injection valve provided in an exhaust passage upstream of the reducing catalyst. NOx in the exhaust gas is purified into harmless components by contacting the reducing agent and promoting the reduction reaction in the reduction catalyst.

  The reduction reaction is a reduction reaction between NOx and ammonia. For example, a urea aqueous solution, an ammonia aqueous solution, or another reducing agent aqueous solution is used as a reducing agent that efficiently generates ammonia. The reducing agent is stored in the reducing agent tank, and a required amount is supplied from the reducing agent tank to the reducing agent injection device based on the exhaust temperature, the NOx emission amount, and the like.

JP 2013-2082 A

  When the hydraulic oil tank and the reducing agent tank are arranged adjacent to each other as in the construction machine described in Patent Document 1, the heat of the hydraulic oil tank propagates to the reducing agent tank, and the reducing agent is altered. There is a risk of adverse effects.

The construction machine according to claim 1 is installed in an exhaust passage of an engine and reduces and purifies nitrogen oxides of exhaust gas with a reducing agent, and a reducing agent that injects the reducing agent into the exhaust passage. An exhaust gas purifying device provided with an injection valve, a traveling body, a revolving body provided on the upper part of the traveling body, and a working device provided on the revolving body. A reducing agent tank that stores the reducing agent injected from the valve and a hydraulic oil tank that stores hydraulic oil used in a hydraulic circuit for driving the working device are disposed adjacent to each other. And an exhaust port positioned above the intake port, and the tank cover is provided with a heat insulating member for suppressing the propagation of heat from the hydraulic oil tank.
The construction machine according to claim 2 is the construction machine according to claim 1, wherein the tank cover has a rectangular box shape and has a side surface facing the hydraulic oil tank and a plurality of side surfaces different from the side surface. However, the intake port is provided on a side surface different from the side surface in the vicinity of the side surface where the outside air temperature is highest among the plurality of side surfaces.
A construction machine according to a third aspect is the construction machine according to the second aspect, wherein the revolving structure includes a main frame that is turnably provided on an upper portion of the traveling body, and a bed that is attached to a side portion of the main frame. The bed is provided with an engine, a heat exchanger for cooling the refrigerant of the engine, a fan device for the heat exchanger, a reducing agent tank, and a hydraulic oil tank. The bed is generated by the fan device for the heat exchanger. And a cooling air guide member that guides the cooling air that has passed through the heat exchanger toward the engine, and that guides the cooling air that has exchanged heat with the engine toward the main frame. It is provided on the surface opposite to the surface on the side.
A construction machine according to a fourth aspect is the construction machine according to any one of the first to third aspects, wherein the reducing agent tank is disposed between the cab and the hydraulic oil tank.
A construction machine according to a fifth aspect is the construction machine according to any one of the first to fourth aspects, further comprising a tank cover fan device for discharging the gas in the tank cover to the outside.

  According to the present invention, even if the hydraulic oil tank and the reducing agent tank are disposed adjacent to each other, the temperature rise of the reducing agent tank can be suppressed and the influence on the reducing agent can be suppressed.

The side view of the crawler crane which is an example of the construction machine which concerns on 1st Embodiment. The perspective view which looked at the turning body of the crawler crane of FIG. 1 from diagonally backward. The side surface schematic diagram which shows the turning body and traveling body of FIG. The plane schematic diagram which looked at the turning body and traveling body of FIG. 3 from the upper direction. The perspective view which shows the front part of the right side bed attached to the main frame. The schematic diagram which shows the various apparatuses arrange | positioned on a right side bed. The schematic diagram which shows typically the positional relationship of a driver's cab, a urea water tank, and a hydraulic oil tank, and the heat insulating material provided in the tank cover. The schematic diagram which shows typically the piping around a urea water tank, and the flow of the air in a tank cover. The schematic diagram which shows typically the flow of the cooling air which generate | occur | produced with the radiator fan. (A) is a plane schematic diagram which shows a temperature measurement point, (b) is a side surface schematic diagram which shows a temperature measurement point. The figure which looked at the exhaust-gas purification apparatus from diagonally upper left of the crane. The schematic diagram which shows the structure of an exhaust-gas purification apparatus. The schematic diagram which shows typically the flow of the air in a fan apparatus provided in the tank cover of the construction machine which concerns on 2nd Embodiment, and a tank cover. The plane schematic diagram which shows the various apparatuses arrange | positioned on the left side bed of the construction machine which concerns on the modification 1. As shown in FIG.

Hereinafter, an embodiment of a construction machine according to the present invention will be described with reference to the drawings.
-First embodiment-
FIG. 1 is a side view of a crawler crane (hereinafter referred to as a crane) as an example of a construction machine according to the present invention, and FIG. 2 is a perspective view of a swing body 103 of the crane of FIG. In the following, as shown in the drawing, the up and down, front and rear, and left and right directions of the crane are defined based on the postures of FIGS.

  As shown in FIG. 1, the crane includes a traveling body 101, a revolving body 103 that is turnably provided on an upper portion of the traveling body 101 via a turning wheel, and a boom that is pivotally supported by the revolving body 103. 104. The traveling body 101 has a track frame (not shown) and side frames 101a provided on both sides of the track frame (not shown), and an endless track crawler belt 101b is attached to the side frame 101a. As shown in FIGS. 1 and 2, a cab (cabin) 107 is provided at the front portion of the swing body 103, and a counterweight 109 is attached to the rear portion of the swing body 103.

  FIG. 3 is a schematic side view showing the revolving structure 103 and the traveling body 101 of FIG. 1, and FIG. 4 is a schematic plan view of the revolving structure 103 and the traveling body 101 of FIG. 3 and 4, the rectangular box-shaped building covers 131C and 132C (see FIG. 2) are not shown. In FIG. 4, the exhaust gas purification device 160 shown in FIG. 3 is not shown. As shown in FIG. 4, the revolving structure 103 includes a main frame 130, a left bed 131, a right bed 132, a cab bed 133, and a main frame 130 that are turnably provided on a track frame (not shown) of the traveling body 101. It is comprised including. The main frame 130 is provided so as to extend in the front-rear direction at the center in the left-right direction of the crane. The left bed 131 is attached to the left side of the main frame 130, and the right bed 132 is attached to the right side of the main frame 130. The cab bed 133 is attached to the main frame 130 in front of the right bed 132, and the cab 107 is disposed on the cab bed 133.

  The main frame 130 is equipped with a hoisting drum 105 that is a winch drum for raising and lowering a hook, and a hoisting drum 106 that is a winch drum for raising and lowering a boom. As shown in FIG. 1, a hoisting rope 105 a is wound around the hoisting drum 105, and the hoisting rope 105 a is wound or fed out by the rotation of the hoisting drum 105, and the hook 108 moves up and down. A hoisting rope 106 a is wound around the hoisting drum 106, and the hoisting rope 106 a is wound or fed out by driving of the hoisting drum 106, and the boom 104 is raised and lowered.

  As shown in FIG. 4, although not shown, various hydraulic devices such as a hydraulic valve device are mounted on the left bed 131, and these devices are covered with a building cover 131C (see FIG. 2). As shown in FIGS. 3 and 4, various devices such as an engine 140, a hydraulic pump 141, a hydraulic valve device (not shown), a radiator 142, and an exhaust gas purification device 160 are mounted on the right bed 132. Is covered with a building cover 132C (see FIG. 2). A hydraulic oil tank 143 that stores hydraulic oil and a urea water tank 150 that stores a urea aqueous solution (hereinafter referred to as urea water) are disposed adjacent to the front portion of the right bed 132. The hydraulic oil tank 143 and the urea water tank 150 are rectangular box-shaped containers, respectively. The urea water tank 150 is covered with a tank cover 151 as will be described later. As described above, in this embodiment, the engine 140, the exhaust gas purification device 160, the urea water tank 150, and the hydraulic oil tank 143 are placed on a single bed (the right bed 132) to form a single module. Yes.

  As shown in FIG. 4, the left bed 131 includes a left frame member 136L and a right frame member 136R extending in the front-rear direction. The left frame member 136L and the right frame member 136R have a substantially U-shaped cross section, and are disposed so that the substantially U-shaped opening sides face each other. The left frame member 136L and the right frame member 136R are connected by a plurality of connecting members extending in the left-right direction. The left and right ends of each connection member are connected to the inner peripheral surfaces of the substantially U-shaped cross sections of the left frame member 136L and the right frame member 136R, respectively. The left frame member 136L and the right frame member 136R between the left frame member 136L and the right frame member 136R are provided with attachment portions for attaching various devices to the side portion and the connection member.

  The configuration of the right bed 132 is substantially the same as that of the left bed 131. That is, the right bed 132 includes a left frame member 137L and a right frame member 137R extending in the front-rear direction. The left frame member 137L and the right frame member 137R have a substantially U-shaped cross section, and are disposed so that the substantially U-shaped opening sides face each other. The left frame member 137L and the right frame member 137R are connected by a plurality of connection members 139 extending in the left-right direction. The left and right ends of the connecting member 139 are connected to the inner peripheral surfaces of the left frame member 137L and the right frame member 137R, respectively, having a substantially U-shaped cross section (see FIG. 5). An attachment portion 138 for attaching various devices to the side portion of the left frame member 137L, the side portion of the right frame member 137R, and the connection member 139 between the left frame member 137L and the right frame member 137R (see FIG. 6). ) Is provided.

  FIG. 5 is a perspective view showing a front portion of the right bed 132 attached to the main frame 130. In FIG. 5, the boom 104, the cab 107, and the cab bed 133 are not shown. The main frame 130 is orthogonal between the bottom plate 110, a pair of left and right vertical plates 111 erected on the bottom plate 110, an upper plate 112 joined to the upper surface of each vertical plate 111, and the left and right vertical plates 111. And an intermediate plate 113 provided.

  The left frame member 137 </ b> L of the right bed 132 is fastened to the main frame 130 with bolts while being in contact with the vertical plate 111 and the bottom plate 110 constituting the right side portion of the main frame 130. Although not shown, the left bed 131 is similarly bolted to the main frame 130 with the right frame member 136R of the left bed 131 in contact with the vertical plate 111 and the bottom plate 110 constituting the left side of the main frame 130, respectively. It is concluded with.

  The arrangement of the device on the right bed 132 will be described. FIG. 6 is a schematic diagram showing various devices arranged on the right bed 132. In FIG. 6, the building cover 132C (see FIG. 2) and the tank cover 151 (see FIG. 2) are not shown. The urea water tank 150 is disposed at the front end of the right bed 132 and is covered with a rectangular box-shaped tank cover 151 (see FIG. 5). In the tank cover 151, a urea water pump 165 (see FIG. 8), which will be described later, is disposed.

  As shown in FIGS. 5 and 8, the tank cover 151 includes a front plate 151 f disposed on the right side of the urea water tank 150, a back plate 151 r disposed on the left side of the urea water tank 150, and the urea water tank 150. A pair of side plates 151 s disposed on the front and rear sides, an upper surface plate 151 t disposed above the urea water tank 150, and a mounting table 155 on which the urea water tank 150 is mounted. The front plate 151f is a door member that can be opened and closed via a hinge. By opening the front plate 151f, the urea water tank 150 is replenished with urea water and the urea water tank 150 and the urea water pump 165 are maintained. It can be carried out.

  The mounting table 155 is a rectangular box-shaped member and is fixed to the right bed 132. As shown in FIGS. 7 and 8, the mounting table 155 has a rectangular flat plate-shaped mounting plate 155p and extends from the four sides of the mounting plate 155p toward the right bed 132 and is mounted on the right bed 132. And a support plate 155s. The pair of side plates 151s, the front plate 151f, and the back plate 151r are mounted and fixed on the edge of the mounting plate 155p of the mounting table 155, respectively.

  FIG. 7 is a schematic diagram schematically showing the positional relationship between the cab 107, the urea water tank 150, and the hydraulic oil tank 143, and the heat insulating material 190 provided in the tank cover 151. As shown in FIG. 7, the urea water tank 150 is disposed between the cab 107 and the hydraulic oil tank 143. A heat insulating material 190 is adhered to the inner surface of the tank cover 151 of the urea water tank 150. Specifically, the inner surfaces of the pair of side plates 151s, the inner surface of the back plate 151r, and the upper surface of the flat plate member extending in the left-right direction of the crane at the upper portion of the right bed 132 below the mounting plate 155p are pasted. It is worn. The heat insulating material 190 is made of a material that is lower than the thermal conductivity of the material constituting the tank cover 151, and effectively suppresses the heat from the hydraulic oil tank 143 from propagating to the urea water tank 150. be able to.

  As shown in FIG. 5, the front plate 151 f is provided with an intake port 15 i for introducing outside air into the tank cover 151, and air whose temperature has risen in the tank cover 151 is outside the tank cover 151 on the top plate 151 t. An exhaust port 15e is provided for discharge. The intake port 15i is provided with a louver that prevents rain and the like from entering, and the exhaust port 15e is provided with a rain cover 159 that prevents the rain and the like from entering. In the louver, a plurality of blades extending in the horizontal direction are assembled in a rectangular frame in parallel with a gap.

  The rain protection cover 159 has a top plate facing the exhaust port 15e, a side plate extending from the edge of the top plate toward the upper surface plate 151t, and an opening 159a having an open front surface. FIG. 8 is a schematic diagram schematically showing the piping around the urea water tank and the flow of air in the tank cover. FIG. 8A shows the urea water tank 150 viewed from the front. In FIG. 8A, the side plate 151s in front of the urea water tank 150 is omitted, and the urea water tank 150 and the urea water pump 165 disposed in the tank cover 151 are shown. FIG. 8B is a view of the tank cover 151 as viewed from the left. In FIG. 8, the flow of air introduced into the tank cover 151 from the intake port 15i and discharged from the exhaust port 15e is schematically indicated by arrows.

  When heat from the hydraulic oil tank 143 is transmitted to the tank cover 151, the temperature of the air in the tank cover 151 gradually increases. As the air in the tank cover 151 is warmed, natural convection occurs in the tank cover 151. The warmed air rises and is discharged from the exhaust port 15e at the top of the tank cover 151.

  As described above, the tank cover 151 that covers the urea water tank 150 is provided with the intake port 15i and the exhaust port 15e positioned above the intake port 15i, thereby preventing heat from being generated in the tank cover 151. be able to.

  As shown in FIG. 6, a hydraulic oil tank 143 is disposed behind the urea water tank 150 and adjacent to the urea water tank 150. In the present embodiment, a gap of about several tens of millimeters is provided between the hydraulic oil tank 143 and the tank cover 151. A hydraulic pump 141 is disposed behind the hydraulic oil tank 143, and an engine 140 is disposed behind the hydraulic pump 141. The hydraulic pump 141 is mechanically connected to the engine 140 and is driven by the engine 140 to supply hydraulic oil (not shown) stored in the hydraulic oil tank 143 to a hydraulic circuit (not shown). The hook 108 is driven. The hoisting drum 106 and the hoisting drum 105 are driven by hydraulic oil supplied to a hydraulic circuit (not shown), and the boom 104 is raised and lowered and the suspended load suspended from the hook 108 is raised and lowered.

  A radiator 142 and a radiator fan 144 are disposed behind the engine 140. The radiator fan 144 is driven by the engine 140, sucks outside air from the rear of the crane, and discharges it toward the front of the crane. With reference to FIG. 9, the flow of the cooling air generated by the radiator fan 144 will be described. FIG. 9 is a schematic diagram schematically showing the flow of cooling air generated by the radiator fan 144 by arrows.

  As shown in FIG. 9, the cooling air generated by the radiator fan 144 passes through the radiator 142, and the engine cooling water (refrigerant) is cooled. The cooling air that has passed through the radiator 142 is introduced into the building cover 132C from the air inlet 134 provided on the rear side surface (side surface on the counterweight 109 side) of the building cover 132C, and the engine 140, the hydraulic pump 141, and the like are cooled. . An exhaust port 135 for discharging cooling air is provided on the left side surface (side surface on the main frame 130 side) of the building cover 132C. The exhaust port 135 is provided with a louver (not shown) that prevents rain and the like from entering.

  That is, the building cover 132C of the right bed 132 guides the cooling air generated by the radiator fan 144 and passed through the radiator 142, which is a heat exchanger, toward the engine 140, and the cooling air heat-exchanged with the engine 140 is main frame. It functions as a cooling air guide member that guides it toward 130.

  The reason why the exhaust port 135 is provided on the left side surface (the main frame 130 side surface) of the building cover 132C is as follows. When an exhaust port is provided on the right side surface (the surface opposite to the main frame 130 side) of the building cover 132C, when there is an operator on the right side of the crane, the heated cooling air may hit the operator, The influence of noise around the crane is increased.

  When an exhaust port is provided on the bottom surface of the building cover 132C and the cooling air is discharged toward the lower side of the right bed 132, dust on the ground is wound up, heat is generated below the right bed 132, and high-temperature air is discharged from the radiator. By being sucked in by the fan 144, the cooling efficiency of the engine coolant may be deteriorated. For this reason, when the exhaust port is provided on the bottom surface of the building cover 132C, the exhaust port is provided as far as possible from the radiator fan 144 and measures such as changing the direction of the exhaust port in a direction in which dust is not easily generated are taken. It is preferable.

  When an exhaust port is provided on the upper surface of the building cover 132C, there is a risk that falling objects such as rain may enter the building cover 132C. For this reason, when providing an exhaust port on the upper surface of the building cover 132C, it is preferable to take measures such as providing a rain cover.

  Therefore, in the present embodiment, the exhaust port 135 is provided on the left side surface of the building cover 132C in order to reduce the influence on the surroundings of the crane and prevent the cooling efficiency of the engine coolant from deteriorating. In addition, when sufficient exhaust area is not securable only by the exhaust port 135 of the left side surface of the building cover 132C, you may provide after taking the countermeasure mentioned above on the bottom face and upper surface of the building cover 132C.

  Due to the influence of cooling air generated by the radiator fan 144, the temperature of the air near the back plate 151 r outside the tank cover 151 becomes higher than the temperature of the air near the front plate 151 f outside the tank cover 151.

  In the present embodiment, as shown in FIG. 8, the intake port 15i is provided on the front plate 151f constituting the tank cover side opposite to the back plate 151r constituting the tank cover side on the main frame 130 side. ing. For this reason, as shown in FIG. 9, the cooling air discharged from the building cover 132 </ b> C toward the main frame 130, that is, warmed by heat exchange with each heat source (engine cooling water in the radiator 142, engine 140). Cooling air can be prevented from flowing into the tank cover 151. That is, by providing the intake port 15i on the front plate 151f, the side opposite to the main frame 130 side (front plate 151f side) where the temperature is lower than the outside air temperature near the main frame 130 side (back plate 151r side) of the tank cover 151. ) Since the outside air in the vicinity can be introduced into the tank cover 151, the temperature rise of the urea water can be effectively suppressed.

  With reference to FIG. 10, the outside temperature measurement result in the vicinity of each side surface (front plate 151 f, back plate 151 r, pair of side plates 151 s) of tank cover 151 will be described during the crane operation. FIG. 10A is a schematic plan view showing temperature measurement points P1, P2, P3, and P4, and FIG. 10B is a schematic side view showing temperature measurement points P1, P2, P3, and P4. As shown in FIG. 10, in the temperature measurement, the outside air temperature (atmosphere temperature) at a position about dmm away from the outer surface of the plate constituting the side surface of the tank cover 151 that opposes each central portion of the front, rear, left and right side surfaces of the urea water tank 150 ) Was measured with a thermocouple temperature sensor. dmm is, for example, about 5 to 10 mm. Further, as shown in the figure, the measurement positions in the vertical direction are set so that the temperature measurement points P1, P2, P3, and P4 have the same height h from the upper surface of the mounting plate 155p.

  As a result of the temperature measurement, the outside air temperature near the rear side plate 151s (measurement point P1) facing the hydraulic oil tank 143 is the first highest, and the outside air temperature near the back plate 151r (measurement point P2) is the second highest. The outside air temperature in the vicinity of the front side plate 151s (measurement point P3) facing the cab 107 was the third highest, and the outside air temperature in the vicinity of the front plate 151f (measurement point P4) was the lowest. The reason why the outside air temperature in the vicinity of the side plate 151s (measurement point P1) facing the hydraulic oil tank 143 is the highest is that it is greatly affected by the heat from the hydraulic oil tank 143. The outside air temperature in the vicinity of the back plate 151r (measurement point P2) and the outside air temperature in the vicinity of the side plate 151s (measurement point P3) facing the cab 107 are higher than the outside air temperature in the vicinity of the front plate 151f (measurement point P4). This is because the cooling air heated by the engine 140 or the like flows in the vicinity of the back plate 151r of the tank cover 151 and further flows between the cab 107 and the tank cover 151. Thus, in the present embodiment, the intake port 15i is provided on the side surface of the four side surfaces of the tank cover 151 where the outside air temperature near the side surface is the lowest.

  As shown in FIG. 6, an exhaust gas purification device 160 is disposed above the hydraulic pump 141. The exhaust gas purifying device 160 is supported by a support base 169 fixed to the mounting portion 138 of the right bed 132. The exhaust gas purification device 160 will be described with reference to FIGS. 11 and 12. FIG. 11 is a view of the exhaust gas purification device 160 as viewed from the upper left side of the crane, and FIG. 12 is a schematic diagram showing the configuration of the exhaust gas purification device 160.

  As shown in FIGS. 11 and 12, the exhaust gas purification device 160 includes an oxidation catalyst device 161, a NOx purification device 162, and a urea water injection device 163 installed in the exhaust passage of the engine 140. . The oxidation catalyst device 161 includes an oxidation catalyst (DOC: Diesel Oxidation Catalyst) that oxidizes and removes nitrogen monoxide (NO), carbon monoxide (CO), hydrocarbon (HC), and the like contained in the exhaust gas. . The NOx purification device 162 is a device that includes a reduction catalyst that reduces and purifies nitrogen oxides (NOx) contained in exhaust gas using urea water. The NOx purification device 162 is configured, for example, such that a urea SCR (Selective Catalytic Reduction) is provided on the upstream side in the cylinder and an oxidation catalyst is provided on the downstream side of the urea SCR.

  The urea water injection device 163 is installed on the upstream side of the NOx purification device 162. The urea water injection device 163 includes a urea water injection valve 164 connected to the urea water tank 150 via the urea water supply pipe 152 and the urea water pump 165. The urea water injection valve 164 generates a magnetic flux in a magnetic circuit including a mover and a core by passing a current through the coil, and opens and closes the valve body by applying a magnetic attractive force that attracts the mover toward the core. This is performed and has the same configuration as a well-known electromagnetically driven fuel injection valve (injector).

  The urea water injection valve 164 injects urea water into the exhaust passage in response to a control signal from a control device (not shown). When the urea water is injected, ammonia is generated from the urea water by the urea SCR of the NOx purification device 162, and NOx in the exhaust gas is reduced by the ammonia and decomposed into water and nitrogen. Ammonia in the exhaust gas is reduced by the oxidation catalyst provided on the downstream side of the urea SCR of the NOx purification device 162.

  As shown in FIG. 12, the urea water pump 165 and the urea water tank 150 are connected by a suction pipe 153a and a return pipe 153b. The urea water pump 165 and the urea water injection valve 164 are connected by a urea water supply pipe 152. The suction pipe 153 a has a urea water inlet 154 a disposed near the bottom of the urea water tank 150, and the return pipe 153 b has a urea water outlet 154 b disposed near the top of the urea water tank 150. The urea water sucked up from the bottom of the urea water tank 150 by the urea water pump 165 is supplied into the urea water supply pipe 152 and pressurized. The urea water in the urea water supply pipe 152 is supplied to the exhaust passage of the engine 140 when the urea water injection valve 164 is opened. The surplus urea water is returned to the urea water tank 150 via the return pipe 153b.

  The urea water freezes at about -11 ° C. When the crane operation is performed in winter or in a cold region, the urea water cannot be supplied to the urea water injection device 163 if the urea water is frozen. For this reason, in order to use the urea water injection device 163, it is necessary to thaw the frozen urea water and prevent the thawed urea water from freezing again. Therefore, in this embodiment, the following thawing / freezing prevention system is provided.

  The thawing / freezing prevention system is a system in which engine cooling water heated by exchanging heat with the engine 140 is guided to the urea water tank 150 and the urea water injection valve 164 to exchange heat between the engine cooling water and the urea water. By this thawing / freezing prevention system, the frozen urea water can be thawed and the thawed urea water can be prevented from freezing again. The thawing / freezing prevention system includes an engine cooling system 180 and a refrigerant pipe 181 that guides the engine cooling water from the engine cooling system 180 to the urea water tank 150.

  The engine cooling system 180 cools the engine 140 by supplying engine cooling water cooled by the radiator 142 to the engine 140. The engine 140 is provided with a cooling water pump (not shown) for circulating engine cooling water and a thermostat 182. The thermostat 182 opens and closes the path of the engine cooling system 180 between fully closed and fully open according to the temperature of the engine coolant.

  Although not shown, a bypass path is provided in the engine to bypass the engine cooling water so that the engine cooling water is not supplied to the radiator 142 when the thermostat 182 is fully closed. If the temperature of the engine cooling water is low when the engine is started, the engine cooling water circulates in the engine and is warmed by the heat generated by the engine 140.

  The refrigerant pipe 181 through which the engine cooling water flows includes a first refrigerant pipe 156 arranged so as to pass through the urea water injection valve 164 and a second refrigerant pipe arranged so as to pass through the urea water tank 150. Path 157. The first refrigerant pipe 156 includes a first supply pipe 156 s that guides the engine cooling water heated by the engine 140 to the urea water injection valve 164, and a first return that returns the engine cooling water from the urea water injection valve 164 to the engine 140. A conduit 156r. The second refrigerant pipe 157 includes a second supply pipe 157 s that guides the engine cooling water heated by the engine 140 to the urea water tank 150, and a second return pipe that returns the engine cooling water from the urea water tank 150 to the engine 140. 157r. The second refrigerant pipe 157 is provided with a switching valve 157v that is switched between fully closed and fully opened in response to a control signal from a control device (not shown).

  The piping around the urea water tank will be described with reference to FIG. As shown in FIG. 8A, the suction pipe 153a and the return pipe 153b are inserted into the urea water tank 150 from the upper surface of the urea water tank 150, respectively. The suction pipe 153 a and the return pipe 153 b are connected to a urea water pump 165 disposed at the upper part in the tank cover 151. The urea water supply pipe 152 through which the urea water discharged from the urea water pump 165 flows is guided to the outside of the tank cover 151 through the opening of the back plate 151r of the tank cover 151, and is connected to the urea water injection valve 164. (See FIGS. 11 and 12).

  The second supply pipe 157 s constituting the second refrigerant pipe 157 is led into the tank cover from the outside of the tank cover 151 through the opening of the back plate 151 r and is inserted from the opening on the upper surface of the urea water tank 150. Yes. The second return pipe 157r constituting the second refrigerant pipe 157 is led from the opening on the upper surface of the urea water tank 150 to the outside of the urea water tank 150, and further outside the tank cover 151 through the opening of the back plate 151r. Is connected to the engine 140 (see FIG. 12). That is, the second refrigerant pipe 157 through which the engine coolant flows is disposed so as to pass through the urea water tank 150.

According to the first embodiment described above, the following operational effects are obtained.
(1) The urea water tank 150 is covered with a tank cover 151 having an intake port 15i and an exhaust port 15e positioned above the intake port 15i. The tank cover 151 has heat from the hydraulic oil tank 143. A heat insulating material 190 for suppressing propagation is provided. Thereby, even if the hydraulic oil tank 143 and the urea water tank 150 are adjacently arranged, the temperature rise of the urea water tank 150 can be suppressed and the influence on the urea water can be suppressed.

(2) In the right bed 132, the cooling air generated by the radiator fan 144 and passed through the radiator 142, which is a heat exchanger, is guided toward the engine 140, and the cooling air exchanged with the engine 140 is transferred to the main frame 130. A building cover 132 </ b> C is provided as a cooling air guide member that is directed toward the building. The intake port 15i of the tank cover 151 is provided in a front plate 151f which is a side plate opposite to the main frame 130 in consideration of the flow of cooling air. This prevents the cooling air warmed by heat exchange with the heat source such as the engine cooling water or the engine 140 from flowing into the tank cover 151, and the front plate having a lower temperature than the outside air near the back plate 151r. By introducing the outside air in the vicinity of 151f, the temperature rise of the urea water can be effectively suppressed.

(3) The urea water tank 150 is disposed between the cab 107 and the hydraulic oil tank 143. For this reason, the heat from the hydraulic oil tank 143 is shielded by the tank cover 151 of the urea water tank 150, and the heat can be prevented from being transmitted into the cab 107. By sticking the heat insulating material 190 to the inner surface of the tank cover 151 of the urea water tank 150, the transfer of heat to the cab 107 can be further suppressed.

(4) The urea water tank 150 is disposed adjacent to the cab 107. Thereby, the temperature of urea water can also be adjusted by introduce | transducing into the tank cover 151 the ventilation from the air-conditioning equipment arrange | positioned in the cab 107. FIG.

(5) The urea water tank 150 is disposed adjacent to the rear of the cab 107, and the engine 140, the hydraulic pump 141, and the exhaust gas purification device 160 are disposed behind the urea water tank 150. Thereby, the noise generated by the engine 140, the exhaust gas purification device 160, and the hydraulic pump 141 can be shielded by the tank cover 151 of the urea water tank 150, and the noise can be prevented from being transmitted into the cab 107.

-Second Embodiment-
A construction machine according to a second embodiment will be described with reference to FIG. In the figure, the same reference numerals are assigned to the same or corresponding parts as those in the first embodiment, and the differences will be mainly described. The construction machine according to the second embodiment has the same configuration as the construction machine according to the first embodiment. FIG. 13 is a view similar to FIG. 8 and is a schematic view schematically showing the fan device 258 provided in the tank cover 151 of the construction machine according to the second embodiment and the air flow in the tank cover. is there.

  In the second embodiment, a fan device 258 is provided at the exhaust port 15 e of the tank cover 151. The fan device 258 sucks up air in the tank cover 151 and discharges the air in the tank cover 151 to the outside of the tank cover 151 through the exhaust port 15e. By forced convection by the fan device 258, outside air having a temperature lower than that in the tank cover 151 can be effectively sucked into the tank cover 151 from the intake port 15i of the front plate 151f.

  According to such 2nd Embodiment, there exists an effect similar to 1st Embodiment. Further, by generating forced convection by the fan device 258, it is possible to prevent heat from being generated in the tank cover 151 more effectively than in the first embodiment. Note that the rotational speed of the fan device 258 may be adjusted in order to set the inside of the tank cover 151 to an appropriate temperature range.

The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.
(Modification 1)
In the above-described embodiment, the example in which the engine 140, the exhaust gas purification device 160, and the urea water tank 150 are disposed in the right bed 132 out of the left bed 131 and the right bed 132 has been described. It is not limited. For example, as shown in FIG. 14, the engine 140, the exhaust gas purification device 160, and the urea water tank 150 may be disposed on the left bed 131. In the construction machine according to the first modification, a radiator 142, an engine 140, a hydraulic pump 141, a hydraulic oil tank 143, and a urea water tank 150 are disposed from the front to the rear of the left bed 131. The exhaust gas purification device 160 is disposed above the hydraulic pump 141.

(Modification 2)
One of the left bed 131 and the right bed 132 may be omitted, and the engine 140, the exhaust gas purification device 160, and the urea water tank 150 may be disposed on the other.

(Modification 3)
In the above-described embodiment, the example using urea water (urea aqueous solution) as the reducing agent has been described, but the present invention is not limited to this. The present invention can be applied to a construction machine provided with an exhaust gas purifying device using various reducing agents such as an aqueous ammonia solution.

(Modification 4)
In the embodiment described above, the building cover 132 </ b> C is configured as a cooling air guide member that guides the cooling air generated by the radiator fan 144 and passing through the radiator 142 to the main frame 130 after passing the engine 140. However, the present invention is not limited to this.

(Modification 5)
In the above-described embodiment, the heat insulating material 190 provided in the tank cover 151 is arranged in the left-right direction of the crane on the inner surface of the pair of side plates 151s, the inner surface of the back plate 151r, and the upper right bed 132 below the mounting plate 155p. Although the example stuck on each of the upper surface of the extending flat member was demonstrated, this invention is not limited to this. For example, the heat insulating material 190 may be attached to the lower surface of the mounting plate 155p instead of the upper surface of the flat plate member extending in the left-right direction of the crane at the upper portion of the right bed 132 below the mounting plate 155p. Furthermore, the heat insulating material 190 may be provided on the inner surface of the upper surface plate 151t and the front plate 151f and the inner surface of the support plate 155s of the mounting table 155.

(Modification 6)
The structures of the urea water tank 150 and the tank cover 151 are not limited to a rectangular box shape, and may be, for example, a polygonal cylinder shape or a cylindrical shape. As for the arrangement structure of the urea water tank 150 in the tank cover 151, the urea water tank 150 may be suspended and supported without using the mounting table 155.

(Modification 7)
In the above-described embodiment, the example in which the intake port 15i is provided in the front plate 151f has been described, but the present invention is not limited to this. For example, the intake port 15 i may be provided not only on the front plate 151 f but also on the front side plate 151 s facing the cab 107. Further, instead of the front plate 151f, the intake port 15i may be provided on the front side plate 151s facing the cab 107. At least, the intake port 15i has a side surface (front plate 151f or a side surface different from the side surface (back plate 151r) having the highest outside air temperature (atmosphere temperature) in the vicinity of the side surface among the side surfaces different from the side surface facing the hydraulic oil tank 143 Preferably, it is provided on the side plate 151 s facing the cab 107, and constitutes the side surface of the four side surfaces (front plate 151 f, back plate 151 r, pair of side plates 151 s) that has the lowest outside air temperature in the vicinity of the side surfaces. More preferably, it is provided on the front plate 151f, that is, on the side surface opposite to the side surface on the main frame side. By providing the intake port 15i on the side surface of the tank cover that is less affected by the cooling air generated by the radiator fan 144, the temperature rise of the urea water tank 150 can be effectively suppressed.

(Modification 8)
In the above-described embodiment, an example in which the present invention is applied to a crawler crane has been described. However, the present invention can also be applied to a mobile crane such as a telescopic crane or a fixed crane. Furthermore, the present invention can be similarly applied to various construction machines such as a hydraulic excavator and a wheel loader.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

15e exhaust port, 15i intake port, 101 traveling body, 101a side frame,
101b Endless track crawler, 103 slewing body, 104 boom, 105 hoisting drum, 105a hoisting rope, 106 hoisting drum, 106a hoisting rope, 107 cab, 108 hook, 109 counterweight, 110 bottom plate, 111 vertical plate, 112 upper Plate, 113 intermediate plate, 130 main frame, 131 left bed, 131C building cover, 132 right bed, 132C building cover, 133 cab bed, 134 air inlet, 135 exhaust port, 136L left frame member, 136R right frame member, 137L left side Frame member, 137R right frame member, 138 mounting portion, 139 connecting member, 140 engine, 141 hydraulic pump, 142 radiator, 143 hydraulic oil tank, 144 radiator fan, 150 urea water tank, 151 tank cover 151f Front plate, 151r Back plate, 151s Side plate, 151t Top plate, 152 Urea water supply piping, 153a Suction piping, 153b Return piping, 154a Inlet, 154b Outlet, 155 Mounting table, 155p Mounting plate, 155s Supporting plate 156 1st refrigerant line, 156r 1st return line, 156s 1st supply line, 157 2nd refrigerant line, 157r 2nd return line, 157s 2nd supply line, 157v selector valve, 159 rain protection cover 159a opening, 160 exhaust gas purification device, 161 oxidation catalyst device, 162 NOx purification device, 163 urea water injection device, 164 urea water injection valve, 165 urea water pump, 169 support base, 180 engine cooling system, 181 refrigerant pipe Road, 182 thermostat, 190 insulation, 258 fan device

Claims (5)

An exhaust gas purification apparatus provided in the exhaust flow path of the engine, comprising a reduction catalyst for reducing and purifying nitrogen oxides of exhaust gas with a reducing agent, and a reducing agent injection valve for injecting the reducing agent into the exhaust flow path When,
A traveling body,
A swivel body provided so as to be turnable on an upper portion of the traveling body;
A working device provided on the swivel body,
Adjacent to the swivel body are a reducing agent tank that stores the reducing agent injected from the reducing agent injection valve and a hydraulic oil tank that stores hydraulic oil used in a hydraulic circuit for driving the working device. Arranged,
The reducing agent tank is covered with a tank cover having an intake port and an exhaust port positioned above the intake port;
A construction machine in which the tank cover is provided with a heat insulating member for suppressing heat propagation from the hydraulic oil tank. The construction machine according to claim 1,
The tank cover has a rectangular box shape, and has a side surface facing the hydraulic oil tank, and a plurality of side surfaces different from the side surface,
The said inlet is a construction machine provided in the side surface different from the side surface in which the external temperature near the side surface becomes the highest among these side surfaces. The construction machine according to claim 2,
The swivel body includes a main frame that is turnable on an upper portion of the traveling body, and a bed that is attached to a side portion of the main frame,
The bed is provided with the engine, a heat exchanger that cools the refrigerant of the engine, a fan device for a heat exchanger, the reducing agent tank, and the hydraulic oil tank.
In the bed, the cooling air generated by the heat exchanger fan device and passed through the heat exchanger is guided toward the engine, and the cooling air heat-exchanged with the engine is guided toward the main frame. A cooling air guide member is provided,
A construction machine in which an intake port of the tank cover is provided on a surface opposite to the surface on the main frame side. The construction machine according to any one of claims 1 to 3,
The reducing agent tank is a construction machine disposed between a cab and the hydraulic oil tank. The construction machine according to any one of claims 1 to 4,
A construction machine comprising a tank cover fan device for discharging the gas in the tank cover to the outside.

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