Machine main body and working machine

Abstract

A machine body (11) includes a swing frame (16) having a floor (16b). The machine body (11) includes an engine. The machine body (11) includes an exhaust gas cleaning device that performs reduction processing on predetermined oxides in exhaust gas of the engine by injecting a liquid reducing agent. The machine body (11) includes a reducing agent tank that stores the liquid reducing agent. The machine body (11) includes a reducing agent pump (37) that supplies the liquid reducing agent stored in the reducing agent tank to the exhaust gas cleaning device. The machine body (11) includes a cooling fan (33). The machine body (11) is arranged on the floor (16b) of the swing frame (16) and includes an opening section (46) that draws in outside air that cools the reducing agent pump (37) by driving the cooling fan (33). The machine body (11) includes a duct section (48) that guides the outside air taken from the opening section (46) to the cooling fan (33).

Description

TECHNICAL FIELD

[0001] The present application relates to a machine main body having a reductant pump that supplies liquid reductant stored in a reductant tank to an exhaust cleaning device, and a working machine including the machine main body. BACKGROUND

[0002] Generally, a diesel engine is used as an engine of a working machine such as a hydraulic excavator. Since exhaust gas discharged from a diesel engine contains a large amount of nitrogen oxides, an exhaust cleaning device is installed that reduces nitrogen oxides to nitrogen gas by injecting liquid reductant such as urea water into the exhaust gas.

[0003] A reductant tank that stores liquid reductant and an injector that serves as an injection device of the exhaust cleaning device are connected by a pipe, and liquid reductant is pumped from the reductant tank to the injector of the exhaust cleaning device by a reductant pump through the pipe.

[0004] In the case of a large working machine or the like, the distance from the reductant tank to the exhaust cleaning device can be long in layout. For example, a working machine is known in which the reductant tank is arranged at the right front end of the machine main body and the exhaust cleaning device is arranged at the left rear end of the machine main body (see, for example, Patent Documents 1 and 2). Therefore, by arranging the reductant pump midway between the reductant tank and the exhaust cleaning device, an existing typical reductant pump can be used. In this case, it is desirable to cool the reductant pump to maintain the quality of the liquid reductant.

[0005] In this regard, for example, a working machine is known in which an opening section is formed in a bottom guard device at the bottom of a swing frame so that the air cleaner can be accessed from below the air cleaner for maintenance such as replacement of the filter of the air cleaner. In this working machine, a hole portion is formed in a cover that detachably covers the opening section with the opening section for accessing the air cleaner, so that external air can be taken in from the hole portion and guided to a radiator (see, for example, Patent Document 3).

[0006] PRIOR ART DOCUMENTS

[0007] [PATENT DOCUMENTS]

[0008] [Patent Document 1] Japanese Patent No. 5501534

[0009] [Patent Document 2] Japanese Patent No. 5636512

[0010] [Patent Document 3] Japanese Patent Application Publication No. H9-221789 SUMMARY

[0011] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0012] However, as described in Patent Literature 3, the reducing agent pump can not be sufficiently cooled by simply sucking the outside air through the intake opening section. Therefore, it is desirable to effectively cool the reducing agent pump with the sucked outside air.

[0013] The present application was completed in view of these points, and an object of the present application is to provide a machine body capable of effectively cooling a reducing agent pump and a work machine including the machine body.

[0014] [Method of solving the problem]

[0015] The application according to claim 1 is a machine body including a frame having a floor; an engine; an exhaust cleaning device that performs a reduction process on a predetermined oxide in exhaust gas of the engine by injecting a liquid reducing agent; a reducing agent tank that stores the liquid reducing agent; a reducing agent pump that supplies the liquid reducing agent stored in the reducing agent tank to the exhaust cleaning device; a cooling fan; an opening section that is provided on the floor of the frame and sucks outside air that cools the reducing agent pump by driving the cooling fan; and a duct section that guides the outside air taken out from the opening section to the cooling fan.

[0016] The application according to claim 2 is the machine body according to claim 1, wherein the opening section is an intake opening section that allows access to the reducing agent pump therethrough.

[0017] The application according to claim 3 is the machine body according to claim 1 or 2, including a tank that stores a fluid, wherein a portion of a wall section of the duct section is formed by a side surface of the tank.

[0018] The application according to claim 4 is a work machine including the machine body according to any one of claims 1 to 3; and a work device mounted on the machine body.

[0019] [Advantages of the present application]

[0020] The application according to claim 1, the reducing agent pump can be arranged in a flow passage of the cooling air from the opening section to the cooling fan, so that the reducing agent pump can be effectively cooled.

[0021] The application according to claim 2, it is not necessary to form a separate opening section for sucking the outside air, and improvement in accessibility of the reducing agent pump and improvement in cooling efficiency of the reducing agent pump can be kept compatible.

[0022] According to the invention of claim 3, the individual components of the wall sections used to form the pipe sections can be reduced by effectively using the side surfaces of the box, and thus the pipe sections can be formed cheaply and easily.

[0023] According to claim 4, a working machine can be provided that can maintain the quality of the liquid reducing agent for a long time by means of a cooling reducing agent pump, and can effectively reduce the exhaust gas discharged from the engine with the liquid reducing agent by means of an exhaust cleaning device. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view showing an embodiment of the machine body according to the present invention.

[0025] Figure 2 This is a perspective view showing the main body of the machine according to the present invention.

[0026] Figure 3 This is a plan view showing the main body of the machine according to the present invention.

[0027] Figure 4 This is a side view showing a working machine including the machine body according to the invention. Detailed Implementation

[0028] In the following text, based on Figures 1 to 4 The present invention is described in detail with reference to one embodiment shown.

[0029] like Figure 4 As shown, the work machine 10, similar to a hydraulic excavator, is configured to include: a machine body 11, which includes a lower traveling body 12 and an upper slewing body 13 disposed on the lower traveling body 12 for rotation; and a work device 14 for various operations and a counterweight 15 mounted on the upper slewing body 13 of the machine body 11. In the example shown, the work device 14 is similar to a bucket, but is not limited thereto, and may be a work device equipped with a crusher or the like.

[0030] The upper slewing body 13 is configured such that the cab 18, which has an operator's seat, is mounted on the slewing frame 16, which serves as the frame, and as... Figure 3 As shown, the control valve, engine 20, pump, housing, cooling assembly 23, exhaust purification system (exhaust aftertreatment system) 24, etc., are mounted on it. The side of the slewing frame 16 is composed of... Figure 4 The outer cover 25 is shown. In the following text, the front-back, left-right, and up-down directions are based on the direction of view from the operator seated in the operator's chair. In the figures, arrows FR and RR indicate the front-back direction, arrows L and R indicate the left-right direction, and arrows U and D indicate the up-down direction.

[0031] like Figure 3As shown, the swing frame 16 has a center frame 26 in the central portion in the left-right direction, which is the lateral direction. The center frame 26 is formed linearly along the front-rear direction. The center frame 26 includes longitudinal plates 26a, 26a (which are a pair of side plates) that are spaced apart from each other in the left-right direction, and a bottom end portion of the work implement 14 is supported by the longitudinal plates 26a, 26a. Figure 4 ) axially between the front portions of these longitudinal plates 26a, 26a.

[0032] Further, the swing frame 16 has side frames 27, 28 on the left and right sides of the center frame 26. The side frames 27, 28 are configured such that a beam member extending in the left-right direction with respect to the center frame 26 is welded, a frame body is welded at a top end portion of the beam member, and a support member is welded. The side frames 27, 28 each extend in the front-rear direction.

[0033] The cab 18( Figure 4 ) is arranged on the left side frame 27. The tank, control valves, the engine 20, pumps, the cooling assembly 23, and the exhaust purification system 24 are arbitrarily arranged according to the space of the swing frame 16. In the present embodiment, the control valves and the engine 20 are arranged on the center frame 26; the pumps and a portion of the exhaust purification system 24 are arranged on the left side frame 27; and at least a portion of the tank, the cooling assembly 23, and the remaining other portions of the exhaust purification system 24 are arranged on the right side frame 28.

[0034] The control valves are supported by the center frame 26 behind the work implement 14, for example. Figure 4 The control valves control the flow rate and direction of hydraulic oil supplied to and discharged from the actuators for travel operation of the lower travel body 12, swing operation of the upper swing body 13, and Figure 4 Operation of the work implement 14 shown.

[0035] Returning to Figure 3 The engine 20 is supported by the center frame 26 behind the control valves. The engine 20 is located at the rear end portion of the swing frame 16. The engine 20 is housed in a machine room.

[0036] Pumps as hydraulic pumps are connected to and driven by the engine 20 to supply hydraulic oil to the control valves and the like. The pumps are housed in a pump room adjacent to the left side of the machine room. Various hydraulic devices and the like can be additionally housed within the pump room.

[0037] The tank includes a fuel tank 30 that stores fuel as a fluid for the engine 20 and a hydraulic oil tank that stores hydraulic oil as a fluid. In the present embodiment, the fuel tank 30 is arranged on the right side frame 28. The hydraulic oil tank (not shown) can be arranged in any space and is arranged on the center frame 26 or the left side frame 27, for example.

[0038] The cooling assembly 23 is a heat exchanger assembly, such as a radiator for primarily cooling engine coolant water, an oil cooler for cooling return oil (i.e., hydraulic oil from the actuators), and an intercooler for cooling the supercharger. The cooling assembly 23 is arranged in a flow passage of cooling air drawn in from a vent formed on a side surface of the upper swing body 13( Figure 1 ) by a cooling fan 33( Figure 4 ) driven by the engine 20 or the electric motor. In the present embodiment, the cooling assembly 23 is arranged at a rear portion of the right side frame 28. Further, the cooling assembly 23 is housed in a machine room adjacent to the engine 20. Further, the cooling assembly 23 is arranged to face the side of the upper swing body 13( Figure 4 ).

[0039] The exhaust purification system 24 then purifies exhaust gas for the exhaust system of the engine 20 by using a liquid reducing agent. The exhaust purification system 24 includes a reducing agent tank 35 that stores the liquid reducing agent, an exhaust cleaning device 36 that treats exhaust gas of the engine 20, and a reducing agent pump 37 that supplies the liquid reducing agent to the exhaust cleaning device 36 by pumping and discharging the liquid reducing agent stored in the reducing agent tank 35, and these are connected by a pipe 38( Figure 1 ).

[0040] The reducing agent tank 35 stores a liquid reducing agent, such as urea water, used in the exhaust cleaning device 36. In the present embodiment, the reducing agent tank 35 is arranged at a front end portion of the right side frame 28. The reducing agent tank 35 is housed in a storage tank for storing, for example, tools. In other words, in the illustrated example, the reducing agent tank 35 is arranged at a right front end portion of the swing frame 16. Further, the reducing agent tank 35 is arranged in front of the fuel tank 30. Further, the reducing agent tank 35 is arranged near a lower portion of the swing frame 16.

[0041] The exhaust gas cleaning apparatus 36 includes a soot removal apparatus (diesel particulate filter) that removes soot in the exhaust gas, a nitrogen oxide reduction apparatus (selective catalytic reduction) that performs reduction processing on nitrogen oxide as a predetermined oxide in the exhaust gas, and a diesel oxidation catalyst. The diesel oxidation catalyst is connected to an exhaust port of the engine 20 by a connection pipe that becomes a starting point of an exhaust passage; the soot removal apparatus is connected to the diesel oxidation catalyst by a connection pipe; the nitrogen oxide reduction apparatus is connected to the soot removal apparatus; and the remaining portion of the exhaust passage is connected to the nitrogen oxide reduction apparatus. An injector that serves as an injection device that injects a liquid reducing agent is arranged in the connection pipe that connects the diesel oxidation catalyst and the soot removal apparatus. In the present embodiment, the injector is located at a rear portion of the exhaust gas cleaning apparatus 36. A supply pipe for supplying the liquid reducing agent from the reducing agent tank 35 by a reducing agent pump 37 is connected to the injector. Then, the liquid reducing agent such as urea water contained in the reducing agent tank 35 is pumped by the reducing agent pump 37 and supplied to the injector of the exhaust gas cleaning apparatus 36 through the supply pipe, and is injected by the injector to the upstream side of the soot removal apparatus.

[0042] In the present embodiment, the exhaust gas cleaning apparatus 36 is arranged at a rear end portion of the left side frame 27. The exhaust gas cleaning apparatus 36 is located above the pump. Further, the exhaust gas cleaning apparatus 36 is housed in a machine room arranged above the pump room. In other words, in the illustrated example, the exhaust gas cleaning apparatus 36 is arranged at a left rear end portion of the swing frame 16. Further, the exhaust gas cleaning apparatus 36 is arranged to be spaced upward from the swing frame 16. Therefore, the exhaust gas cleaning apparatus 36 is positioned spaced apart from the reducing agent tank 35 in the front-rear direction, the left-right direction, and the up-down direction, respectively, and diagonally to the swing frame 16 in a plan view.

[0043] The reducing agent pump 37 is arranged at an intermediate position between the reducing agent tank 35 and the exhaust gas cleaning apparatus 36. In other words, the reducing agent pump 37 is arranged at a position spaced apart from each of the reducing agent tank 35 and the exhaust gas cleaning apparatus 36. In the present embodiment, the reducing agent pump 37 is arranged at a central portion in the front-rear direction of the right side frame 28 of the swing frame 16. In other words, in the illustrated example, the reducing agent pump 37 is located on the same side as the reducing agent tank 35, and on the opposite side in the left-right direction from the exhaust gas cleaning apparatus 36, and at an intermediate position in the front-rear direction between the reducing agent tank 35 and the exhaust gas cleaning apparatus 36. In addition, the reducing agent pump 37 is located behind the fuel tank 30 and in front of the cooling assembly 23. That is, the reducing agent pump 37 is located between the fuel tank 30 and the cooling assembly 23 in the front-rear direction. Therefore, in the right side (right side frame 28) of the swing frame 16, the reducing agent tank 35, the fuel tank 30, the reducing agent pump 37, and the cooling assembly 23 are arranged in this order from the front portion toward the rear portion.

[0044] In addition, as Figure 1 and Figure 2Also shown, the reducing agent pump 37 is arranged near a lower portion of the slewing frame 16. In the present embodiment, the reducing agent pump 37 is mounted on a mounting member 39 fixed to the slewing frame 16. The mounting member 39 is, for example, a reinforcing member of the skirt portion 16a, which is an outer frame portion of the slewing frame 16. The mounting member 39 is formed in a plate shape. In the illustrated example, the mounting member 39 is arranged in the up-down direction and the left-right direction along a main surface, and the reducing agent pump 37 is mounted on a front surface of the mounting member 39. The reducing agent pump 37 is arranged with a filter mounting / demounting portion 37a facing downward. In the illustrated example, the reducing agent pump 37 is located below the skirt portion 16a.

[0045] Further, a lower portion of the reducing agent pump 37 is opposite a floor panel 16b of the slewing frame 16. The lower portion of the reducing agent pump 37 is close to the floor panel 16b and separated upward from the floor panel 16b. The floor panel 16b is formed with an access opening portion 42 that allows access to the reducing agent pump 37. The access opening portion 42 is an opening portion for maintenance of the reducing agent pump 37. The access opening portion 42 enables access to the filter mounting / demounting portion 37a from below, and a filter can be mounted / demounted (replaced) from the filter mounting / demounting portion 37a via the access opening portion 42. In the illustrated example, the access opening portion 42 is opened at the lower portion of the reducing agent pump 37, particularly in an area including a position facing the filter mounting / demounting portion 37a.

[0046] The access opening portion 42 is openable / closable by an opening / closing member 44. The opening / closing member 44 is, for example, a floor protection member formed in a plate shape. In the present embodiment, the opening / closing member 44 is detachably fixed to the floor panel 16b by a fixing member 45 such as a bolt. In other words, the access opening portion 42 is adapted to be opened by removal of the opening / closing member 44. The opening / closing member 44 is formed with a single or a plurality of opening portions 46. That is, the opening portions 46 are arranged in the floor panel 16b of the slewing frame 16. The opening portions 46 are openings that communicate with the access opening portion 42 and through which external air is drawn into the slewing frame 16 (above the slewing frame 16). The opening portions 46 have a smaller opening area than the access opening portion 42. In the present embodiment, the opening portions 46 are located at least at positions facing the lower portion of the reducing agent pump 37. In the illustrated example, the opening portions 46 have a main opening portion 46a located at a position facing the lower portion of the reducing agent pump 37 and an auxiliary opening portion 46b located at a position spaced apart from the main opening portion 46a. In the present embodiment, a plurality of main opening portions 46a are arranged side by side in the front-rear direction. A plurality of auxiliary opening portions 46b are arranged side by side in the front-rear direction and the width direction at positions spaced apart from the lower portion of the reducing agent pump 37 outward in the width direction, i.e., at positions spaced apart to the right of the main opening portions 46a.

[0047] Then, the outside air taken out from the opening section 46 is guided to the cooling assembly 23 or the cooling fan 33 via the duct section 48. The duct section 48 is formed to include a space portion in which the reducing agent pump 37 is arranged. The duct section 48 is formed by allowing the opening section 46 and the intake opening section 42 to communicate with the side of the cooling assembly 23 or the cooling fan 33. Depending on the position at which the reducing agent pump 37 is arranged, the duct section 48 can be formed in any shape by using the space around the position. In the present embodiment, the duct section 48 is formed to extend upward from the reducing agent pump 37 substantially. Further, the duct section 48 is formed adjacent to the machine room. The duct section 48 is formed between the front of the cooling assembly 23 and the rear portion of the fuel tank 30. Further, the duct section 48 is located behind the center of the swing frame 16 in the swing.

[0048] The wall section (outer wall) of the duct section 48 is formed by one or more partition members 50. In the present embodiment, the front portion that is a part of the wall section of the duct section 48 is formed by the rear side surface 30a that is a side of the fuel tank 30 as a tank. Further, in the present embodiment, the right side portion that is a part of the wall section of the duct section 48 is formed by the outer cover 25. The duct section 48 of the present embodiment partitions flow passages having a quadrangular cross section. In the example shown, the inside of the duct section 48 is partitioned into a series of flow passages having a housing space SI that houses the reducing agent pump 37 therein and directly communicates with the opening section 46 and the intake opening section 42, and an air guiding space S2 that guides the outside air from the housing space SI to the cooling assembly 32 or the cooling fan 33. In the present embodiment, the air guiding space S2 is arranged upward with respect to the housing space SI, i.e., outward in the width direction. The air guiding space S2 is formed along the side surface of the machine body 11.

[0049] The partition members 50 can have any number and any shape so that the duct section 48 can be formed. In the present embodiment, the partition members 50 include a first partition member 51, a second partition member 52, a third partition member 53, and a fourth partition member 54.

[0050] The first partition member 51 mainly partitions the housing space SI within the duct section 48. In the present embodiment, the first partition member 51 covers the reducing agent pump 37 from above to rearward and inward (i.e., leftward) in the width direction. More specifically, in the present embodiment, the first partition member 51 includes an upper surface portion 51a that faces the upper portion of the reducing agent pump 37, a rear surface portion 51b that faces the rear portion of the reducing agent pump 37, and a left side surface portion 51c that faces the left portion (i.e., inward along the width direction of the reducing agent pump 37).

[0051] The upper surface portion 51a forms an upper portion of the accommodation space S1 and is inward in the width direction of the duct section 48, i.e., a portion of the wall section on the left side. The upper surface portion 51a is located upwardly spaced from an upper portion of the reductant pump 37. The upper surface portion 51a is parallel or substantially parallel to the floor panel 16b of the slewing frame 16. In the present embodiment, the upper surface portion 51a is located above the skirt section 16a of the slewing frame 16. The rear surface portion 51b forms a portion of the wall section of the rear portion of the duct section 48. The rear surface portion 51b forms a rear portion of the accommodation space S1. In the present embodiment, the left side surface portion 51c forms a portion of the wall section inward in the width direction on the left side of the duct section 48. The left side surface portion 51c forms a left side portion of the accommodation space S1.

[0052] Further, in the present embodiment, the first partition member 51 is arranged to extend over the second partition member 52 and the support member 55. The support member 55 is arranged adjacent to the rear side surface 30a of the fuel tank 30. The support member 55 is formed to have a lower end portion fixed to the slewing frame 16 (the right side frame 28) and to be upright in the up-down direction.

[0053] The second partition member 52 mainly partitions the air guide space S2 within the duct section 48. Further, the second partition member 52 is a plate-like member partitioning the duct section 48 and the machine room. The second partition member 52 forms the remaining other portions of the wall section of the rear portion of the duct section 48. The second partition member 52 forms a rear portion of the air guide space S2. The second partition member 52 is arranged such that a major surface thereof extends in the up-down direction and in the left-right direction.

[0054] The second partition member 52 is attached to a pillar 57 in the machine room. The pillar 57 extends linearly in the up-down direction such that a lower end portion thereof is fixed to the slewing frame 16 (the right side frame 28). In the present embodiment, the pillar 57 is located at a right front end of the machine room.

[0055] Further, in the second partition member 52, a communication opening 58 is formed that communicates between the duct section 48 and the cooling assembly 23 or the cooling fan 33 side, i.e., the machine room. That is, the communication opening 58 allows external air to be supplied from the air guide space S2 to the cooling assembly 23 or the cooling fan 33. The communication opening 58 is formed to penetrate the second partition member 52. A plurality of communication openings 58 are arranged and positioned spaced apart from each other in the up-down direction.

[0056] The third partition member 53 mainly partitions the air guide space S2 within the duct section 48. Further, the third partition member 53 forms the other remaining portions of the left wall section of the duct section 48 in the width direction, i.e., in the present embodiment. The third partition member 53 forms a left side portion of the air guide space S2. The third partition member 53 is arranged such that a major surface thereof extends in the up-down direction and in the left-right direction with respect to the outer cover 25 Figure 4) is positioned inward in the width direction and, in this embodiment, is separated to the left, and faces the outer cover 25 Figure 4 ) The third partition member 53 is arranged so that its main surface extends in the front-rear direction and the up-down direction. That is, the second partition member 52 and the third partition member 53 are arranged so that their main surfaces intersect each other. The third partition member 53 extends forward from the front portion of the second partition member 52. Further, the third partition member 53 has a longitudinal shape in the up-down direction. The third partition member 53 is arranged so as to extend over the second partition member 52 and the support member 55.

[0057] The fourth partition member 54 partitions the air guide space S2 within the duct section 48. Further, the fourth partition member 54 forms the upper portion of the duct section 48 and the air guide space S2. The fourth partition member 54 is attached to the upper portion of the third partition member 53, and is arranged so as to extend over the second partition member 52 and the support member 55.

[0058] At least any one of the first partition member 51 to the fourth partition member 54 can be integrally formed or can be further divided into a plurality of members. Further, at least a portion of the first partition member 51 can be integrally formed with the second partition member 52 or the third partition member 53. Similarly, at least a portion of the second partition member 52 can be integrally formed with at least any one of the first partition member 51 to the fourth partition member 54; at least a portion of the third partition member 53 can be integrally formed with the first partition member 51, the second partition member 52, or the fourth partition member 54; and at least a portion of the fourth partition member 54 can be integrally formed with the second partition member 52 or the third partition member 53. In short, depending on the dimensions of the space in which the duct section 48 is installed and the desired shape of the duct section 48, the manner in which the partition member 50 is formed by division or integration and the shape of the partition member 50 can be arbitrarily set.

[0059] The rear side surface 30a of the fuel tank 30 constituting the front portion of the wall section of the duct section 48 is formed in a planar shape and is arranged in the up-down direction and the left-right direction. The rear side surface 30a of the fuel tank 30 spans the accommodation space SI and the air guide space S2 of the duct section 48 and forms the respective front portions thereof.

[0060] Then, during operation of the work machine 10, hydraulic oil is pumped and discharged from the hydraulic oil tank by a pump driven by power obtained from the engine 20 in accordance with operation by an operator, and is supplied to and discharged from various actuators by a control valve, whereby the work machine 10 is enabled to perform such as running, turning, various work, and the like.

[0061] The exhaust gas of the engine 20 is purified by an exhaust gas purification system 24. More specifically, in the exhaust gas purification system 24, a liquid reductant such as urea water contained in a reductant tank 35 is pumped by a reductant pump 37 and supplied to an injector of an exhaust gas cleaning device 36 through a pipe 38, and is injected by the injector to an upstream side of the exhaust gas cleaning device; thus, nitrogen oxides contained in the exhaust gas of the engine 20 are reduced to nitrogen gas.

[0062] By driving the cooling fan 33 to suck the outside air into the cooling assembly 23 from the vent, the cooling water of the engine 20 and the injector, the oil return from the actuator, or the air temperature-increased due to the compression of the supercharger of the engine 20, etc. are cooled, respectively.

[0063] Similarly, by driving the cooling fan 33, the outside air is sucked into the accommodation space S1 of the duct section 48 from the opening section 46, and the reductant pump 37 is cooled by the outside air. The outside air sucked mainly from the main opening section 46a of the opening section 46 is directly blown to the reductant pump 37 so that the reductant pump 37 is cooled, and the outside air sucked from the auxiliary opening section 46b of the opening section 46 flows into the air guide space S2 to secure the amount of outside air sucked into the duct section 48. The sucked outside air is further sucked into the cooling assembly 23 from the air guide space S2 of the duct section 48 through the communication opening 58, and then passes through the cooling assembly 23 to cool the cooling assembly 23.

[0064] In this way, the outside air for cooling the reductant pump 37 by driving the cooling fan 33 is sucked from the opening section 46 arranged in the floor 16b of the swing frame 16, and the outside air sucked from the opening section 46 is guided to the cooling fan 33 through the duct section 48. Therefore, the reductant pump 37 can be arranged in the flow passage of the cooling air from the opening section 46 to the cooling fan 33, so that the reductant pump 37 can be efficiently cooled.

[0065] Therefore, even when the reductant pump 37 is arranged apart from the reductant tank 35 and the exhaust gas cleaning device 36 as in the large working machine 10, the reductant pump 37 can be efficiently cooled, so that the deterioration of the liquid reductant due to the overheating of the reductant pump 37 can be suppressed, and the quality of the liquid reductant can be maintained. In other words, the degree of freedom of the layout of the exhaust gas purification system 24 including the reductant tank 35, the exhaust gas cleaning device 36, and the reductant pump 37 can be increased while maintaining the quality of the liquid reductant.

[0066] Further, when maintenance of the reductant pump 37 is performed, the opening / closing member 44 is removed from the bottom plate 16b of the swing frame 16 during shutdown of the work machine 10, and the reductant pump 37 enters from the entry opening section 42 when opened. For example, a filter of the reductant pump 37 can be replaced at the filter mounting / demounting portion 37a. In this way, by allowing the opening section 46 to communicate with the duct section 48 via the entry opening section 42 that can access the reductant pump 37, the entry opening section 42 can be efficiently used, and the accessibility of the reductant pump 37 and the cooling efficiency of the reductant pump 37 can be achieved.

[0067] Further, the outside air that is drawn into the duct section 48 from the opening section 46 passes through the cooling assembly 23 to cool the cooling assembly 23, so that the opening section 46 can also function as a vent that draws in outside air to cool the cooling assembly 23. Thus, the opening section 46 of the present embodiment can increase the amount of outside air drawn in for cooling the cooling assembly 23.

[0068] Further, by utilizing the structure around the reductant pump 37, the duct section 48 can be easily formed by assembling the partition member 50.

[0069] Since a portion of the wall section of the duct section 48 is formed by a tank, i.e., the side surface of the fuel tank 30 in the present embodiment, by efficiently utilizing the side surface of the fuel tank 30, a separate member for forming the wall section of the duct section 48 can be reduced, and the duct section 48 can be formed inexpensively and easily.

[0070] Then, by including the machine body 11 as described above, a work machine 10 can be provided that can maintain the quality of the liquid reductant for a long time by cooling the reductant pump 37 and effectively reducing the exhaust gas discharged from the engine 20 with the liquid reductant by the exhaust gas cleaning device 36.

[0071] In the above-described one embodiment, the side surface of the fuel tank 30 is used as a portion of the wall section of the duct section 48, but is not limited thereto; and if a tank is adjacent to a position where the duct section 48 is formed, a side surface of other tank, such as a hydraulic oil tank, can be used as a portion of the wall section of the duct section 48. Similarly, in addition to using the side surface of a tank as a portion of the wall section of the duct section 48, a side surface of other structure adjacent or close to the duct section 48 can be used as a portion of the wall section of the duct section 48.

[0072] Depending on the size of the entry opening section 42, the entry opening section 42 can be used as the opening section 46 that draws in outside air into the duct section 48. In this way, by using the entry opening section 42 as the opening section 46, a separate opening section for drawing in outside air does not have to be formed, and the improvement of the accessibility of the reductant pump 37 and the compatibility of the cooling efficiency of the reductant pump 37 can be maintained.

[0073] Industrial applicability

[0074] The present application can be utilized by business operators included in the manufacturing industry of machine bodies and working machines having a reductant pump for supplying a reductant to an exhaust gas cleaning device.

Claims

1. A machine body comprising: a frame having a floor; an engine; an exhaust cleaning device that performs reduction treatment on predetermined oxides in exhaust gas of the engine by injecting a liquid reducing agent; a reducing agent tank that stores the liquid reducing agent; a reducing agent pump that supplies the liquid reducing agent stored in the reducing agent tank to the exhaust cleaning device, the reducing agent pump being disposed at a position spaced apart from the reducing agent tank; a cooling fan; an opening section that is provided on the floor of the frame and that draws in outside air that cools the reducing agent pump by driving the cooling fan; and a duct section that guides the outside air taken out from the opening section to the cooling fan; wherein a lower portion of the reducing agent pump opposes the floor, and the opening section is an access opening section formed in the floor that allows access to the reducing agent pump.

2. The machine body according to claim 1, comprising: a fuel tank, wherein a portion of a wall section of the duct section is formed by a side surface of the fuel tank.

3. A work machine comprising: the machine body according to any one of claims 1 to 2; and a work device mounted on the machine body. ​

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