Working machinery

Abstract

To provide a work machine capable of preventing a coolant leaked from an air conditioner system from reaching an engine.SOLUTION: A work machine includes: a bracket for supporting a cooling fan and a heat exchanger by an upper surface; an undercover mounted on a lower surface of the bracket; a compressor for compressing a coolant; and an air conditioning unit for supplying cool air controlled to a predetermined temperature by the coolant that is compressed by the compressor and is heat-exchanged by the heat exchanger, into a cab. Between the bracket and the undercover, an internal space is formed. In the bracket, a notch connected to the internal space is provided. A pipe conduit for circulating the coolant among the compressor, the heat exchanger and the air conditioning unit is stored in the internal space, and extends toward each of the compressor, the heat exchanger and the air conditioning unit by the notch. Between the bracket and the undercover, a partition wall for airtightly blocking the internal space is provided.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a work machine equipped with an air conditioner.

Background Art

[0002] Conventionally, there has been known a work machine including a cab, a cooling fan that generates cooling air, an engine arranged downstream of the cooling fan in the flow direction of cooling air, a heat exchanger arranged upstream of the cooling fan in the flow direction of cooling air, and an air conditioning system that circulates a refrigerant to supply cool air into the cab.

[0003] In such a work machine, slightly flammable HFO1234yf, which has a lower global warming potential than HFC134a, may sometimes be used as the refrigerant circulating in the air conditioning system. Accordingly, Patent Document 1 discloses an air-conditioning refrigerant gas leakage alarm device that detects refrigerant leakage and issues an alarm to an occupant.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] However, if the refrigerant leaks upstream of the engine in the flow direction of cooling air, the leaked slightly flammable refrigerant may be drawn into the engine room before the occupant who received the alarm can take action.

[0006] The present invention has been made in view of the above-described actual situation, and an object of the present invention is to provide a work machine capable of preventing refrigerant leaking from an air conditioning system from reaching the engine.

Means for Solving the Problem

[0007] To achieve the above objective, the present invention provides a work machine comprising a cab, a cooling fan for generating cooling air, an engine positioned downstream of the cooling fan in the direction of cooling air flow, a heat exchanger positioned upstream of the cooling fan in the direction of cooling air flow, a bracket supporting the cooling fan and the heat exchanger on its upper surface, an under cover attached to the lower surface of the bracket, and an air conditioning system for supplying cool air into the cab, wherein the air conditioning system comprises a compressor for compressing a refrigerant, and the refrigerant compressed by the compressor and heat-exchanged by the heat exchanger The vehicle is equipped with an air conditioning unit that supplies cool air adjusted to a predetermined temperature into the cab, and an internal space is formed between the bracket and the under cover, the bracket is provided with a notch that connects to the internal space, and the piping for circulating the refrigerant between the compressor, the heat exchanger and the air conditioning unit is housed in the internal space and extends toward the compressor, the heat exchanger and the air conditioning unit, respectively through the notch, and a partition wall is provided between the bracket and the under cover to airtightly close the internal space. The partition wall is, at least a portion thereof, a resin sealing material that is compressed and placed between the bracket and the under cover. It is characterized by the following: [Effects of the Invention]

[0008] According to the present invention, it is possible to obtain a work machine that prevents refrigerant leaking from the air conditioning system from reaching the engine. Other problems, configurations, and effects will be clarified by the following description of embodiments. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view of a hydraulic excavator. [Figure 2] This is a plan view of the upper rotating body. [Figure 3] This is an upper rear perspective view of the swivel frame. [Figure 4] This is a downward perspective view of the swivel frame. [Figure 5] This is a schematic diagram of an air conditioning system installed in a hydraulic excavator. [Figure 6] This is a disassembled perspective view of the bracket and under cover. [Figure 7] This is a perspective view of the bracket. [Figure 8] This diagram shows the relative positions of the bracket and the sealing material. [Figure 9] Figure 8 shows a cross-sectional view from IX to IX. [Figure 10] This is a control block diagram for a hydraulic excavator. [Modes for carrying out the invention]

[0010] An embodiment of the hydraulic excavator 1 (working machine) according to the present invention will be described with reference to the drawings. Note that the specific working machine is not limited to the hydraulic excavator 1, but may also be a wheel loader, crane, dump truck, etc. Furthermore, unless otherwise specified, the terms front, back, left, and right in this specification refer to the viewpoint of the operator riding and operating the hydraulic excavator 1.

[0011] Figure 1 is a side view of a hydraulic excavator 1. As shown in Figure 1, the hydraulic excavator 1 comprises a lower traveling body 2 and an upper rotating body 3 supported by the lower traveling body 2. The lower traveling body 2 and the upper rotating body 3 are examples of the vehicle body. The lower traveling body 2 is equipped with a pair of left and right crawlers 4, which are continuous tracks. Driven by a travel motor 5, the pair of left and right crawlers 4 rotate independently. As a result, the hydraulic excavator 1 moves. However, the lower traveling body 2 may be wheeled instead of having crawlers 4.

[0012] The upper slewing body 3 is supported by the lower traveling body 2 so as to be rotatable by a slewing motor 6. The upper slewing body 3 mainly consists of a base slewing frame 7, a cab (driver's seat) 8 located on the front left side of the slewing frame 7, a counterweight 9 located at the rear of the slewing frame 7, and a front work implement 10 (working device) mounted on the front center of the slewing frame 7 so as to be rotatable in the vertical direction.

[0013] The cab 8 is formed with a space for an operator who operates the hydraulic excavator 1 to ride. Inside the cab 8, there are arranged a seat on which the operator sits, an operating device operated by the operator seated on the seat, a display 8A (see Fig. 2), and an air conditioner unit 36 (see Fig. 2).

[0014] The operating device receives an operator's operation for actuating the hydraulic excavator 1. When the operating device is operated by the operator, the lower traveling structure 2 travels, the upper swinging structure 3 swings, and the front working implement 10 operates. Specific examples of the operating device include levers, steering wheels, pedals, switches, and the like.

[0015] The display 8A is an example of a notification device that notifies information to the operator riding in the cab 8. Specific examples of the notification device are not limited to the display 8A, and may be LED lamps, speakers, or a combination thereof.

[0016] The front working implement 10 includes a boom 11 vertically pivotably supported by the upper swinging structure 3, an arm 12 rotatably supported at a distal end of the boom 11, a bucket 13 rotatably supported at a distal end of the arm 12, a boom cylinder 14 that drives the boom 11, an arm cylinder 15 that drives the arm 12, and a bucket cylinder 16 that drives the bucket 13. The counterweight 9 is for balancing the weight with the front working implement 10, and is a heavy object having an arcuate shape in a top view.

[0017] Further, the upper swinging structure 3 supports an engine housing 20 (housing). The engine housing 20 is supported by the swing frame 7 rearward of the cab 8 and the front working implement 10 and forward of the counterweight 9. The engine housing 20 has a space for accommodating components for operating the hydraulic excavator 1.

[0018] FIG. 2 is a plan view of the upper revolving structure 3. FIG. 3 is an upper rear perspective view of the revolving frame 7. FIG. 4 is a lower perspective view of the revolving frame 7. As shown in FIGS. 2 to 4, an engine 21, a cooling fan 22, a heat exchanger 23 and the like, which are components for operating the hydraulic excavator 1, are housed inside an engine building 20.

[0019] The engine 21 is disposed to the right of the cooling fan 22 and the heat exchanger 23. The engine 21 generates driving force for operating the hydraulic excavator 1 by mixing fossil fuel and air and combusting the mixture.

[0020] The cooling fan 22 is disposed to the left of the engine 21 and to the right of the heat exchanger 23. The cooling fan 22 generates cooling air that flows from left to right inside the engine building 20. As one example, the cooling fan 22 is directly connected to an output shaft of the engine 21 and rotates. As another example, the cooling fan 22 is rotated by the driving force of a driving source (not shown) such as a hydraulic motor or an electric motor.

[0021] The heat exchanger 23 is disposed to the left of the engine 21 and the cooling fan 22. The heat exchanger 23 includes a radiator that causes cooling coolant that has cooled the engine 21 to exchange heat with cooling air, and a condenser 32 that causes a refrigerant circulating in an air conditioner system 30, which will be described later, to exchange heat with cooling air. In addition, the heat exchanger 23 may further include an intercooler that cools air compressed by a supercharger (turbocharger), a hydraulic oil cooler that cools hydraulic oil stored in a hydraulic oil tank, and the like.

[0022] Note that, as shown in FIGS. 3 and 4, the cooling fan 22 and the heat exchanger 23 according to the present embodiment are unitized to form a radiator assembly 24. However, the cooling fan 22 and the heat exchanger 23 may be each independently arranged inside the engine building 20 without being unitized.

[0023] As shown in Figure 1, an air intake port 25 is formed on the left side of the engine building 20. Furthermore, an exhaust port (not shown) is formed on the right side of the engine building 20. When the cooling fan 22 rotates, the air (cooling air) that flows into the engine building 20 from the air intake port 25 passes through the heat exchanger 23 and the engine 21, and is discharged to the outside of the engine building 20 from the exhaust port.

[0024] The direction of the cooling airflow generated by the cooling fan 22 is not limited to left to right; it may also be right to left. In this case, the arrangement of the engine 21, cooling fan 22, and heat exchanger 23 is reversed left to right. That is, the engine 21 should be positioned downstream of the cooling fan 22 in the direction of cooling airflow within the engine building 20. The heat exchanger 23 should be positioned upstream of the cooling fan 22 in the direction of cooling airflow within the engine building 20.

[0025] Furthermore, the hydraulic excavator 1 is equipped with an air conditioning system 30. Figure 5 is a schematic diagram of the air conditioning system 30 installed in the hydraulic excavator 1. The air conditioning system 30 supplies air (cold or warm) adjusted to a predetermined temperature into the cab 8. As shown in Figure 5, the air conditioning system 30 mainly comprises a compressor 31, a condenser 32, an expansion valve 33, an evaporator 34, and a blower fan 35.

[0026] The compressor 31 compresses the refrigerant circulating within the air conditioning system 30. This causes the temperature of the refrigerant to rise. The condenser 32 exchanges heat between the refrigerant compressed by the compressor 31 (i.e., whose temperature has risen) and the cooling air generated by the cooling fan 22. This causes the temperature of the refrigerant to decrease. In other words, thermal energy is removed from the refrigerant.

[0027] The expansion valve 33 expands the refrigerant that has undergone heat exchange in the condenser 32. As a result, the temperature of the refrigerant decreases compared to before it flows into the compressor 31. The evaporator 34 generates cool air by exchanging heat between the air generated by the blower fan 35 and the refrigerant that has been expanded (i.e., whose temperature has decreased) in the expansion valve 33. The cool air generated by the evaporator 34 is then supplied into the cab 8. The evaporator 34 and the blower fan 35 constitute the air conditioning unit 36 ​​installed in the cab 8. Furthermore, the refrigerant whose temperature has risen due to heat exchange is supplied back to the compressor 31.

[0028] In this way, the refrigerant circulates within the air conditioning system 30 through the conduit 37 connecting the compressor 31, condenser 32, expansion valve 33, and evaporator 34. Then, as the refrigerant circulates clockwise within the air conditioning system 30 shown in Figure 5, cold air is supplied into the cab 8. On the other hand, as the refrigerant circulates counterclockwise within the air conditioning system 30 shown in Figure 5, warm air is supplied into the cab 8.

[0029] The conduit 37 is a passage (pipe, hose, etc.) through which the refrigerant passes. The conduit 37 consists of conduit 37A connecting the compressor 31 and the condenser 32, conduit 37B connecting the condenser 32 and the expansion valve 33, conduit 37C connecting the expansion valve 33 and the evaporator 34, and conduit 37D connecting the evaporator 34 and the compressor 31. Furthermore, as the refrigerant circulating through the conduit 37 in the air conditioning system 30, for example, a slightly flammable HFO1234yf is used.

[0030] As shown in Figure 4, the radiator assembly 24 is supported on the upper surface of a bracket 40 attached to the swivel frame 7. A portion of the conduit 37 is routed along the lower surface of the bracket 40. Furthermore, an under cover 41 (see Figure 6) is attached to the lower surface of the bracket 40. That is, a portion of the conduit 37 is routed into an internal space 46 (see Figure 9) formed between the bracket 40 and the under cover 41. This internal space 46 between the bracket 40 and the under cover 41 is then airtightly sealed by sealing materials 43A, 43B, 43C, 43D, 43E, 43F, 43G, and 43H (see Figures 6 to 8).

[0031] Figure 6 is an exploded perspective view of the bracket 40 and the under cover 41. Figure 7 is a perspective view of the bracket 40. Figure 8 is a diagram showing the positional relationship between the bracket 40 and the sealing material 43. Figure 9 is a cross-sectional view taken along line IX-IX in Figure 8.

[0032] As shown in Figure 4, the bracket 40 is positioned at the left rear corner of the slewing frame 7. More specifically, as shown in Figures 4 and 6, the bracket 40 is attached to the rear plate 7B and the left side plate 7L of the slewing frame 7. The bracket 40 is composed of a first bracket 44 and a second bracket 45. The slewing frame 7, the first bracket 44, the second bracket 45, and the under cover 41 (described later) are made of, for example, steel plate (an example of a metal material).

[0033] The rear end of the first bracket 44 is fixed to the back panel 7B. The first bracket 44 also extends parallel to the left side panel 7L (i.e., in the front-to-back direction). Furthermore, the front end of the first bracket 44 is connected to the center of the second bracket 45. The left end of the second bracket 45 is fixed to the left side panel 7L. Furthermore, the second bracket 45 extends parallel to the back panel 7B (i.e., in the left-to-right direction). Furthermore, the center of the second bracket 45 is connected to the front end of the first bracket 44. In other words, the bracket 40 is constructed by combining the first bracket 44 and the second bracket 45 in a T-shape.

[0034] Furthermore, as shown in Figure 7, the first bracket 44 is composed of a main wall 44A and a pair of protruding walls 44B and 44C. The main wall 44A is a flat plate that extends in the front-rear and left-right directions. The main wall 44A has a flattened shape in which the length in the front-rear direction is longer than the length in the left-right direction. The protruding wall 44B protrudes downward from the left end of the main wall 44A and extends in the front-rear direction. The protruding wall 44C protrudes downward from the right end of the main wall 44A and extends in the front-rear direction.

[0035] Furthermore, as shown in Figure 7(B), notches 44D and 44E are formed in a portion of the rear side of the protruding walls 44B and 44C. In addition, a notch 45A is formed in a portion of the second bracket 45 connected to the front end of the first bracket 44. The notches 44D, 44E, and 45A are gaps that connect to the internal space 46. The notches 44D, 44E, and 45A are also gaps that allow the conduits 37A, 37B, and 37D to extend out of the internal space 46.

[0036] As shown in Figure 6, the under cover 41 has a generally flat outer shape. The under cover 41 is fixed to the slewing frame 7 below the first bracket 44. Furthermore, as shown in Figure 9, the under cover 41 faces the first bracket 44 (more specifically, the main wall 44A) at a predetermined distance in the vertical direction. That is, the internal space 46 is surrounded by the under cover 41, the main wall 44A, and a pair of protruding walls 44B and 44C.

[0037] As shown in Figure 8, the internal space 46 houses parts of the pipes 37A, 37B, and 37D. Parts of the pipes 37A, 37B, and 37D extend roughly in the front-rear direction between a pair of protruding walls 44B and 44C. In other words, protruding wall 44B is located upstream of the pipes 37A, 37B, and 37D in the direction of cooling air flow, and protruding wall 44C is located downstream of the pipes 37A, 37B, and 37D in the direction of cooling air flow.

[0038] The conduits 37A and 37D extend out of the internal space 46 through the notch 44E and are connected to the compressor 31. More specifically, after extending out of the notch 44E, the conduits 37A and 37D pass behind the engine 21 and reach the compressor 31, which is located to the right of the engine 21. In addition, the conduits 37A and 37B extend out of the internal space 46 through the notch 44D and are connected to the condenser 32. Furthermore, the conduits 37B and 37D extend out of the internal space 46 through the notch 45A and are connected to the expansion valve 33 and evaporator 34, which are located in front of the second bracket 45.

[0039] The rear end of the internal space 46 is closed by the back plate 7B of the slewing frame 7. The front end of the internal space 46 is closed by the second bracket 45. In other words, the front and rear ends of the internal space 46 are sealed by metal-to-metal contact. The back plate 7B and the second bracket 45 are examples of partitions that seal the internal space 46 airtight.

[0040] The sealing materials 43A to 43H are made of a material that is impermeable to gases and is flexible (in other words, has elastic deformability). The sealing materials 43A to 43H are, for example, made of resin. Examples of resin materials that make up the sealing materials 43A to 43H include ethylene propylene rubber (EPDM) and urethane foam.

[0041] As shown in Figure 6, sealing materials 43A and 43B are attached to the upper surface of the under cover 41. The sealing materials 43A and 43B are spaced apart in the left-right direction (i.e., in the direction of cooling airflow) and each extends in the front-rear direction. The sealing materials 43A and 43B are also positioned facing the protruding walls 44B and 44C.

[0042] Furthermore, as shown in Figure 6, the sealant 43C is positioned on the sealant 43A at a location corresponding to the notch 44D. The sealant 43D is positioned on the sealant 43B at a location corresponding to the notch 44E. The sealant 43E is positioned on the under cover 41 at a location corresponding to the notch 45A.

[0043] Furthermore, as shown in Figure 7(B), the sealants 43F, 43G, and 43H are positioned on the lower surface of the first bracket 44 (more specifically, the main wall 44A) at the locations of the notches 44D, 44E, and 45A. In other words, the sealants 43C to 43E (second sealants) and the sealants 43F to 43H (first sealants) are positioned facing each other in the vertical direction.

[0044] When the under cover 41 and the first bracket 44 are assembled, the sealing materials 43A and 43B are positioned in a compressed state between the under cover 41 and the first bracket 44. More specifically, as shown in Figure 9, the sealing materials 43A and 43B are positioned in a compressed state between the upper surface of the under cover 41 and the protruding ends of the protruding walls 44B and 44C. The sealing materials 43A and 43B are another example of a partition that airtightly seals the internal space 46. That is, the back plate 7B, the second bracket 45, and the sealing materials 43A and 43B airtightly seal the internal space 46 so as to surround a portion of the conduits 37A, 37B, and 37D.

[0045] The sealants 43C and 43F maintain airtightness at the notch 44D by contacting each other in a compressed state. The pipes 37A and 37B extend from the notch 44D, passing between the sealants 43C and 43F. The sealants 43D and 43G maintain airtightness at the notch 44E by contacting each other in a compressed state. The pipes 37A and 37D extend from the notch 44E, passing between the sealants 43D and 43G. The sealants 43E and 43H maintain airtightness at the notch 45A by contacting each other in a compressed state. The pipes 37B and 37D extend from the notch 45A, passing between the sealants 43E and 43H. As a result, the conduits 37A, 37B, and 37D extend out of the internal space 46 through the notches 44D, 44E, and 45A while maintaining the airtightness of the internal space 46.

[0046] Furthermore, as shown in Figure 8, the longitudinal length L1 of the internal space 46 (in other words, the longitudinal length of the first bracket 44) is longer than the longitudinal length L2 of the engine 21. When the hydraulic excavator 1 is viewed from the side, the engine 21 is positioned within the longitudinal range of the internal space 46. More specifically, the front end of the engine 21 is located behind the front end of the internal space 46, and the rear end of the engine 21 is located in front of the rear end of the internal space 46. As a result, the conduit 37 is housed in the internal space 46, which is airtightly sealed by a bulkhead, below the bracket 40, within the range through which the cooling air that flows into the engine building 20 through the air intake 25 and reaches the engine 21 passes.

[0047] Figure 10 is a control block diagram of the hydraulic excavator 1. As shown in Figure 10, the hydraulic excavator 1 includes a controller 50 having a CPU 51 (Central Processing Unit) and memory 52. ​​The memory 52 is composed of, for example, ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), or a combination thereof. The controller 50 performs the processing described later by having the CPU 51 read and execute the program code stored in the memory 52.

[0048] However, the specific configuration of the controller 50 is not limited to this and may be implemented using hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array).

[0049] Furthermore, as shown in Figure 10, the hydraulic excavator 1 is equipped with a refrigerant detection sensor 38 (sensor) that detects refrigerant leakage from the pipeline 37. For example, the refrigerant detection sensor 38 detects the pressure of the refrigerant in the pipeline 37. As another example, the refrigerant detection sensor 38 detects the concentration of the refrigerant in the internal space 46.

[0050] The controller 50 determines that refrigerant is leaking from the pipeline 37 if the refrigerant pressure detected by the refrigerant detection sensor 38 falls below a predetermined threshold, or if the refrigerant concentration detected by the refrigerant detection sensor 38 exceeds a predetermined threshold. When the refrigerant leak is detected by the refrigerant detection sensor 38, the controller 50 may notify the display 8A of the refrigerant leak, or it may stop the engine 21 or the air conditioning system 30.

[0051] According to the above embodiment, for example, the following effects are achieved.

[0052] According to the above embodiment, an airtight internal space 46 is formed directly below the radiator assembly 24, which is located upstream of the engine 21 in the direction of cooling airflow, and a portion of the piping 37 is routed within this internal space 46. This prevents the refrigerant from reaching the engine 21 even if a slightly flammable refrigerant leaks from the piping 37, thanks to the partition wall.

[0053] Furthermore, according to the above embodiment, by constructing at least a portion of the partition wall with resin sealing materials 43A to 43H, leakage of refrigerant from the internal space 46 can be achieved with a simple configuration. However, as mentioned above, the partition wall may also be constructed using metal-to-metal contact.

[0054] In the above embodiment, of the four sides of the internal space 46, the left and right sides facing each other in the direction of cooling airflow were sealed with sealing materials 43A and 43B, while the front and rear sides facing each other in a direction perpendicular to the direction of cooling airflow were sealed with metal-to-metal contact. However, the combination of partitions sealing each side of the internal space 46 is not limited to the example described above.

[0055] Furthermore, according to the above embodiment, the airtightness of the internal space 46 can be improved by compressing and clamping the sealing materials 43A and 43B at the protruding ends of the under cover 41 and the protruding walls 44B and 44C. However, the sealing materials 43A and 43B may also be compressed and clamped between the under cover 41 and the main wall 44A.

[0056] Furthermore, according to the above embodiment, by sandwiching the conduits 37A, 37B, and 37D extending from the internal space 46 with sealing materials 43C to 43H at the positions of the notches 44D, 44E, and 45A, the conduits 37A, 37B, and 37D can be extended from the internal space 46 while maintaining the airtightness of the internal space 46. However, the specific method for extending the conduits 37A, 37B, and 37D while maintaining the airtightness of the internal space 46 is not limited to the above example. As another example, the area around the conduits 37A, 37B, and 37D extending from the notches 44D, 44E, and 45A may be sealed with a sealant.

[0057] Furthermore, according to the above embodiment, by detecting refrigerant leakage with the refrigerant detection sensor 38, the controller 50 can notify the operator of the refrigerant leakage or stop the engine 21 or the air conditioning system 30 before the refrigerant leaking from the pipeline 37 reaches the engine 21.

[0058] The embodiments described above are illustrative for explaining the present invention and are not intended to limit the scope of the invention to those embodiments only. Those skilled in the art can implement the present invention in various other forms without departing from the spirit of the invention. [Explanation of Symbols]

[0059] 1. Hydraulic excavator (working machine) 2 Lower running body 3. Upper rotating body 4 Crawler 5. Driving motor 6. Swivel motor 7. Swivel Frame 7B Back plate (bulkhead) 7L Left side plate 8 cabs 8A Display 9 Counterweight 10 Front work equipment 11 Boom 12 arms 13 buckets 14 Boom Cylinder 15 Arm Cylinder 16 Bucket Cylinder 20 Engine building 21 Engine 22 Cooling Fans 23 Heat exchanger 24 Radiator Assembly 25 Air supply port 30 Air Conditioning System 31 Compressor 32 Capacitors 33 Expansion valve 34 Evaporator 35 Blower Fan 36 Air Conditioning Unit 37 Pipeline 38 Refrigerant detection sensor (sensor) 40 brackets 41 Undercover 43. Sealing material (partition wall) 44 First bracket 44A Main wall 44B,44C Projecting wall 44D, 44E, 45A Notches 45 Second bracket 46 Interior space 50 Controllers 51 CPU 52 memory

Claims

1. The cab and, A cooling fan that generates cooling air, An engine positioned downstream of the cooling fan in the direction of the cooling airflow, A heat exchanger is positioned upstream of the cooling fan in the direction of the cooling airflow, A bracket that supports the cooling fan and the heat exchanger on its upper surface, An under cover attached to the lower surface of the bracket, In a work machine equipped with an air conditioning system that supplies cold air into the cab, The aforementioned air conditioning system, A compressor that compresses the refrigerant, The system includes an air conditioning unit that supplies cold air, which has been compressed by the compressor and heat-exchanged by the heat exchanger, to the cab, and is adjusted to a predetermined temperature by the refrigerant. An internal space is formed between the bracket and the under cover. The bracket is provided with a notch that connects to the internal space. The piping for circulating the refrigerant between the compressor, the heat exchanger, and the air conditioning unit is housed in the internal space and extends outwards from the notches toward the compressor, the heat exchanger, and the air conditioning unit, respectively. A partition wall is provided between the bracket and the under cover to airtightly seal the internal space. A working machine characterized in that at least a portion of the partition wall is a resin sealing material placed in a compressed state between the bracket and the under cover.

2. In the work machine described in claim 1, The aforementioned bracket is The main wall supporting the cooling fan and the heat exchanger, The pipeline has a pair of protruding walls on both the upstream and downstream sides in the direction of cooling airflow, which protrude from the main wall toward the under cover and extend in a direction intersecting the direction of cooling airflow. The working machine is characterized in that the sealing material is placed in a compressed state between the protruding ends of the pair of protruding walls and the under cover.

3. In the work machine described in claim 1, The first sealing material positioned on the bracket side and the second sealing material positioned on the under cover side come into contact in a compressed state, thereby maintaining airtightness at the notch position. The working machine is characterized in that the conduit extends from the notch, passing between the first and second sealing materials.

4. In the work machine described in claim 1, A work machine characterized by being equipped with a sensor for detecting refrigerant leakage from the aforementioned pipeline.

Images