Construction machine

Abstract

A hydraulic shovel (1) is provided with: a cooling fan (8A); a heat exchanger (21) to which the cooling air from the cooling fan (8A) is supplied; an air-conditioning device (24) provided inside the operation cabin (10); and an outside air introduction duct (25) for introducing outside air to the air conditioning device (24). The outside air intake port (25B) of the outside air introduction duct (25) opens toward the upstream side of the flow of the cooling air within the heat exchanger chamber (23) into which the cooling air supplied to the heat exchanger (21) flows.

Description

Technical Field

[0001] The present invention relates to a construction machine such as a hydraulic excavator, and more particularly to a construction machine equipped with an air conditioner. Background Art

[0002] Generally, a hydraulic excavator, which is a typical example of construction machinery, comprises a lower traveling body capable of traveling automatically and an upper revolving body rotatably mounted on the lower traveling body. A working device is provided on the front side of the upper revolving body, and excavation work is performed using the working device.

[0003] The upper revolving body of the hydraulic excavator has a revolving frame that forms a supporting structure. The revolving frame is equipped with a cab, a prime mover such as an engine, a hydraulic pump, a cooling fan, a heat exchanger, etc. The heat exchanger is configured to include, for example, a radiator and an oil cooler, and the heated fluid (refrigerant) such as engine cooling water and working oil is cooled by the cooling air supplied from the cooling fan. The hydraulic excavator sometimes performs excavation operations with the body of the hydraulic excavator staying at a predetermined position. Therefore, the hydraulic excavator needs to always take in external air through the cooling fan and generate cooling air while the engine is driven.

[0004] In addition, an air conditioning device for supplying conditioned air to the cab in the cab is provided on the upper rotating body of the hydraulic excavator. The air conditioning device takes in external air through a pipe to cool or heat the cab. A dust filter is usually installed at the external air intake of the pipe, and dust mixed in the external air is removed by the dust filter (Patent Document 1). The hydraulic excavator of Patent Document 1 is provided with a pipe in the cab, and the external air intake of the pipe is connected to the equipment storage room via an external air intake path. As a result, external air is introduced from the equipment storage room into the air conditioning device via the external air intake path and the pipe, and dust mixed in the external air is captured by the dust filter installed at the external air intake of the pipe.

[0005] On the other hand, there is known a small (rear small swing type) hydraulic excavator used in narrow work sites such as urban areas. This small hydraulic excavator sets the swing radius of the rear end of the upper swing body as small as possible by arranging the prime mover close to the swing center (Patent Document 2). Therefore, in the small hydraulic excavator of Patent Document 2, an air conditioner is arranged in a narrow space formed on the lower side of the cab. The external air inlet of the duct for introducing external air to the air conditioner opens in the space where the heat exchanger is accommodated.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2016-138404

[0009] Patent Document 2: Japanese Patent Application Publication No. 2012-67484 Summary of the invention

[0010] However, in the air conditioning device of Patent Document 1, the inlet of the external air introduction path for taking the external air in the equipment accommodation room into the air conditioning device opens in the equipment accommodation room at a position away from the cooling fan. Therefore, it is difficult to efficiently supply external air to the air conditioning device using the cooling wind flowing into the equipment accommodation room through the cooling fan. On the other hand, in the air conditioning device of Patent Document 2, the external air introduction port of the duct opens in a direction orthogonal to the flow of the cooling wind supplied to the radiator. Therefore, the introduction of external air into the external air introduction port is hindered by the flow of the cooling wind, and it may be impossible to efficiently supply external air to the air conditioning device.

[0011] An object of the present invention is to provide a construction machine capable of efficiently supplying outside air to an air conditioner.

[0012] The engineering machinery of the present invention comprises: a cooling fan that generates cooling air; a heat exchanger that uses the cooling air supplied from the cooling fan to cool a fluid; an exterior cover that covers the cooling fan and the heat exchanger to form a heat exchanger chamber and has a vent for circulating the cooling air with the outside of the vehicle body; a cab that forms a driver's cabin; an air conditioning device that supplies conditioned air into the cab; and a duct that has an external air inlet and is used to introduce external air taken in from the external air inlet into the air conditioning device. The engineering machinery is characterized in that the external air inlet is disposed in the heat exchanger chamber and is configured in a manner that opens toward the upstream side of the flow of the cooling air.

[0013] According to the present invention, when cooling air supplied to the heat exchanger flows into the heat exchanger chamber, part of the cooling air is guided to the outside air intake port of the duct, thereby allowing outside air to be efficiently introduced into the air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a right side view of the hydraulic excavator showing the embodiment of the present invention.

[0015] Figure 2 This is a rear view of the hydraulic excavator as seen from the rear.

[0016] Figure 3 This is a perspective view of the upper rotating body with the right rear side cover removed, as viewed from the right rear.

[0017] Figure 4This is a right side view of the upper rotating body after removing the right rear side cover as viewed from the right side.

[0018] Figure 5 This is a top view of the upper rotating body after removing the right front upper surface cover and the right rear upper surface cover from above.

[0019] Figure 6 This is a rear view of the upper rotating body after removing the counterweight as viewed from the rear. DETAILED DESCRIPTION

[0020] Below, take the small swing type hydraulic excavator as an example, refer to Figures 1 to 6 An embodiment of a construction machine according to the present invention will be described in detail.

[0021] A hydraulic excavator 1 as a typical example of a construction machine includes a crawler-type lower traveling body 2 capable of automatic travel and an upper revolving body 3 rotatably mounted on the lower traveling body 2. A swing-type working device 4 for excavating soil and sand is provided in front of the upper revolving body 3.

[0022] The working device 4 is configured to include a swing column 4A mounted to the front end of a revolving frame 5 described later so as to be swingable in the left-right direction, a boom 4B mounted to the swing column 4A so as to be rotatable, an arm 4C mounted to the front end of the arm 4B so as to be rotatable, a bucket 4D mounted to the front end of the arm 4C so as to be rotatable, and a boom cylinder 4E, an arm cylinder 4F, and a bucket cylinder 4G. In addition, a swing cylinder for swinging the swing column 4A in the left-right direction is provided between the revolving frame 5 and the swing column 4A.

[0023] The upper revolving body 3 includes a revolving frame 5 , a counterweight 6 , an engine 8 , a hydraulic pump 9 , a cab 10 , a left exterior cover 13 , a right front exterior cover 14 , a right rear exterior cover 17 , and the like.

[0024] The revolving frame 5 is a base of the upper revolving body 3, and is rotatably mounted on the lower traveling body 2 via a revolving device. A support bracket 5A protruding forward is provided on the front side of the revolving frame 5, and a swing column 4A of the working device 4 is supported on the support bracket 5A so as to be swingable in the left-right direction. A counterweight 6 is provided on the rear side of the revolving frame 5, and the weight balance with the working device 4 is maintained by the counterweight 6. The counterweight 6 stands up from the revolving frame 5 in a manner covering the engine 8 from the rear, and the lower part of the counterweight 6 is an extension portion 6A extending rearward from the revolving frame 5. An inspection opening (not shown) for inspecting the engine 8, etc. is formed on the upper side of the counterweight 6 than the extension portion 6A, and the inspection opening is covered by the engine cover 7 so as to be openable and closable.

[0025] The engine 8 as a prime mover is located in front of the counterweight 6 and mounted on the revolving frame 5. The engine 8 is mounted on the revolving frame 5 in a horizontal state with a crankshaft (not shown) extending in the left-right direction. A suction-type cooling fan 8A is provided on the right side of the engine 8. The cooling fan 8A generates cooling air by being driven by the engine 8 to rotate, and supplies the cooling air to the heat exchanger 21 described later. A hydraulic pump 9 is provided on the left side of the engine 8. The hydraulic pump 9 sucks in and pressurizes the working oil by being driven by the engine 8, and supplies the working oil (pressure oil) to various hydraulic actuators mounted on the hydraulic excavator 1. In addition, as a prime mover, an electric motor or a hybrid power prime mover combining an engine and an electric motor can be used.

[0026] The cockpit 10 is located in front of the counterweight 6 and mounted on the revolving frame 5. The cockpit 10 is surrounded by a front surface portion 10A, a rear surface portion 10B, a left side surface portion 10C, a right side surface portion 10D, and an upper surface portion 10E, and a driver's room is divided. The cockpit 10 is provided with a driver's seat 11, a travel lever, a pedal device (not shown), an operating lever device 12, and an air conditioning device 24 described later.

[0027] The left exterior cover 13 is arranged on the left side of the revolving frame 5. The left exterior cover 13 stands upward from the left side of the rear portion of the revolving frame 5, and extends from the left end portion of the counterweight 6 toward the left side surface 10C of the cab 10. The left exterior cover 13 is detachably mounted on a support member (not shown) using bolts or the like, and covers the hydraulic pump 9 and the like from the left side.

[0028] The right front exterior cover 14 is disposed on the right front side of the revolving frame 5. The right front exterior cover 14 stands upward from the right side of the front portion of the revolving frame 5, and extends from the front end portion of the right rear exterior cover 17 described later toward the right front corner of the cockpit 10 (the corner where the front surface portion 10A and the right side surface portion 10D intersect). The right front exterior cover 14 has a right front side cover 14A that stands upward from the revolving frame 5, and a right front upper surface cover 14B that closes the upper end of the right front side cover 14A. The right front side cover 14A is detachably mounted on a support member (not shown) using bolts or the like, and covers the fuel tank 15 and the working oil tank 16 from the right side (refer to Figure 5 ). The rear end of the right front upper surface cover 14B is mounted on a support member (not shown) via a hinge mechanism, and the front side of the right front upper surface cover 14B rotates in the vertical direction around the hinge mechanism. Thus, the right front upper surface cover 14B can open and close the upper end of the right front side cover 14A, covering the fuel tank 15 and the working oil tank 16 from above.

[0029] The right rear exterior cover 17 is arranged adjacent to the rear side of the right front exterior cover 14 on the right rear side of the revolving frame 5. The right rear exterior cover 17 stands upward from the right side of the rear portion of the revolving frame 5 and extends from the right end of the counterweight 6 toward the right front exterior cover 14. The right rear exterior cover 17 has a right rear side cover 17A that stands upward from the revolving frame 5 and a right rear upper surface cover 17B that closes the upper end of the right rear side cover 17A. The front end of the right rear side cover 17A is mounted on a support member (not shown) via a hinge mechanism, and the rear side of the right rear side cover 17A rotates in the front-to-back direction with the hinge mechanism as the center. Thus, the right rear side cover 17A covers the heat exchanger chamber 23 described later in an openable and closable manner from the right side. The right rear upper surface cover 17B is detachably mounted on the support member (not shown) using bolts, etc., and covers the heat exchanger chamber 23 from above. In this manner, right rear exterior cover 17 covers cooling fan 8A and heat exchanger 21 , thereby forming heat exchanger chamber 23 .

[0030] A plurality of (e.g., three) vents 17C, 17D, and 17E arranged in the vertical direction are provided on the right rear side cover 17A of the right rear exterior cover 17. These vents 17C, 17D, and 17E allow the heat exchange chamber 23 to communicate with the outside. The cooling wind (outside air) generated by the rotation of the cooling fan 8A flows into the heat exchange chamber 23 through the vents 17C, 17D, and 17E.

[0031] The inner cover 18 is provided between the fuel tank 15 and the hydraulic oil tank 16 and the cockpit 10. The inner cover 18 is formed of a flat plate-shaped member extending in the up-down direction and the front-back direction, and separates the cockpit 10 from the outside. In addition, the inner cover 18 also functions as a bracket for mounting the air conditioning device 24, the external air introduction duct 25, etc., which will be described later.

[0032] The partition member 19 is provided at the rear side of the hydraulic oil tank 16. The partition member 19 is formed of a flat plate-shaped member extending in the up-down direction and the left-right direction, and partitions the hydraulic oil tank 16 from the heat exchanger chamber 23. The heat exchanger bracket 20 is provided between the upper end side of the inner cover 18 and the counterweight 6, and extends in the front-back direction. A heat exchanger 21 is installed between the heat exchanger bracket 20 and the revolving frame 5.

[0033] The heat exchanger 21 is disposed on the right side of the engine 8 in a state of being opposed to the cooling fan 8A in the left-right direction. The heat exchanger 21 includes, for example, a radiator 21A for cooling the engine cooling water and an oil cooler 21B for cooling the working oil. These radiators 21A and oil coolers 21B are installed between the revolving frame 5 and the heat exchanger bracket 20 in a state of being adjacent in the front-back direction. That is, the radiator 21A and the oil cooler 21B are arranged in parallel with respect to the flow direction of the cooling air supplied by the cooling fan 8A. In addition, the heat exchanger bracket 20 and the heat exchanger 21 separate the engine room 22 and the heat exchanger room 23.

[0034] The engine room 22 is provided at the rear side of the upper revolving body 3. The engine room 22 is formed as a space surrounded by the revolving frame 5, the counterweight 6, the engine cover 7, the cab 10, the left exterior cover 13, the heat exchanger bracket 20, the heat exchanger 21, etc. The engine 8, the hydraulic pump 9, etc. are accommodated in the engine room 22.

[0035] The heat exchanger chamber 23 is provided on the right rear side of the upper rotating body 3. The heat exchanger chamber 23 is formed as a space surrounded by the rotating frame 5, the right rear exterior cover 17, the partition member 19, the heat exchanger bracket 20, the heat exchanger 21, etc. The heat exchanger 21, the filter box 26 and the dust filter 27 described later are accommodated in the heat exchanger chamber 23. The heat exchanger chamber 23 is formed as a space isolated from the outside when the right rear exterior cover 17 (right rear side cover 17A) is closed. In addition, by rotating the cooling fan 8A using the engine 8, as shown in FIG. Figure 5 As shown by the middle arrow F, cooling air (outside air) flows into the heat exchanger chamber 23 through the vents 17C, 17D, and 17E of the right rear exterior cover 17. After cooling the heat exchanger 21 (radiator 21A, oil cooler 21B), the cooling air is introduced into the engine room 22 to cool the engine 8 and the hydraulic pump 9 from the outside.

[0036] The air conditioner 24 is provided in the cockpit 10. The air conditioner 24 is arranged close to the right side face 10D of the cockpit 10 when it is installed on the inner cover 18 or the like. A fan, an evaporator, etc. (none of which are shown) are provided inside the air conditioner 24. The air conditioner 24 selectively inhales the air in the cockpit 10 (inside air) and the air outside the cockpit 10 (outside air), and supplies them to the cockpit 10 as conditioned air, thereby adjusting the temperature environment in the cockpit 10 to the temperature desired by the operator.

[0037] The external air introduction duct 25 is connected to the air conditioning device 24, and introduces the air outside the cockpit 10 (external air) into the air conditioning device 24. The external air introduction duct 25 is composed of a cylindrical body extending in the front-to-back direction, and is installed on the inner cover 18 or the like. The front end of the external air introduction duct 25 is a connection port 25A, which is connected to the air conditioning device 24. The external air introduction duct 25 extends rearward while being inclined obliquely upward from the air conditioning device 24. The rear end side of the external air introduction duct 25 is bent toward the heat exchanger chamber 23, and is supported by, for example, the inner cover 18. Furthermore, the rear end of the external air introduction duct 25 is an external air intake port 25B, which opens in the heat exchanger chamber 23. The external air intake port 25B of the external air introduction duct 25 opens toward the upstream side of the flow F of the cooling air flowing into the heat exchanger chamber 23 (refer to Figure 5 ).

[0038] The filter box 26 is arranged in the heat exchanger chamber 23 in a state of being connected to the external air intake port 25B of the external air introduction duct 25. The filter box 26 is formed in a box shape having a connection port 26A connected to the external air intake port 25B of the external air introduction duct 25 and an air intake port 26B protruding into the heat exchanger chamber 23. The air intake port 26B of the filter box 26 is opposite to the right rear exterior cover 17 (right rear side cover 17A). Therefore, when the air conditioner 24 operates, a part of the air that flows into the heat exchanger chamber 23 from the vents 17C, 17D, and 17E of the right rear exterior cover 17 is supplied to the air conditioner 24 from the air intake port 26B of the filter box 26 disposed in the heat exchanger chamber 23 through the external air introduction duct 25.

[0039] The dust filter 27 is detachably mounted on the air inlet 26B of the filter box 26. The dust filter 27 captures dust and the like in the outside air introduced into the air inlet 26B of the filter box 26, and supplies clean outside air to the air conditioner 24 through the outside air introduction duct 25.

[0040] Here, by the rotation of the cooling fan 8A, a large amount of external air (cooling wind) flows into the heat exchanger chamber 23. A part of the cooling wind is guided to the external air inlet 25B of the external air introduction duct 25 opened in the heat exchanger chamber 23, and the external air is efficiently supplied to the air conditioner 24 through the external air introduction duct 25. In this case, the amount of external air sucked by the air conditioner 24 is smaller than the flow rate of the cooling wind (external air) supplied to the heat exchanger 21 through the cooling fan 8A. Therefore, even if dust is originally mixed in the external air flowing into the heat exchanger chamber 23, the intrusion of dust into the external air introduction duct 25 can be suppressed.

[0041] Furthermore, the outside air intake port 25B of the outside air introduction duct 25 opens in the heat exchanger chamber 23 which is isolated from the outside when the right rear exterior cover 17 is closed. Therefore, even when a large amount of dust is scattered around the hydraulic excavator 1 during excavation, the amount of dust that enters the heat exchanger chamber 23 can be suppressed. Therefore, the amount of dust introduced into the air conditioner 24 through the outside air introduction duct 25 is reduced, and clogging of the dust filter 27 installed at the air inlet 26B of the filter box 26 can be suppressed.

[0042] In addition, if Figure 4As shown, the external air inlet 25B of the external air introduction duct 25 equipped with the filter box 26 is arranged above the heat exchanger 21 in the heat exchanger chamber 23. Therefore, it is possible to prevent the cooling air supplied to the heat exchanger 21 through the vents 17C, 17D, and 17E of the right rear exterior cover 17 from directly flowing into the external air introduction duct 25. Thus, it is possible to prevent the dust mixed in the cooling air from flowing into the air conditioning device 24 through the external air introduction duct 25. Moreover, when the cockpit 10 is heated by the air conditioning device 24, the warm air retained above the heat exchanger 21 is guided to the air conditioning device 24 through the external air introduction duct 25, so that the cockpit 10 is efficiently heated.

[0043] And, if Figure 6 As shown, three vents 17C, 17D, and 17E are arranged in the vertical direction on the right rear exterior cover 17 that can cover the heat exchanger chamber 23 in an openable and closable manner. The external air inlet 25B of the external air introduction duct 25 equipped with the filter box 26 is arranged above the vent 17C that is arranged at the uppermost side among the three vents 17C, 17D, and 17E. Thus, even if dust is mixed in the cooling air that flows into the heat exchanger chamber 23 through the vents 17C, 17D, and 17E by the rotation of the cooling fan 8A, it is possible to prevent the dust from intruding into the external air introduction duct 25 through the external air inlet 25B.

[0044] The hydraulic excavator 1 of the present embodiment has the above-described structure. When the hydraulic excavator 1 is used for excavation work, the operator, for example, sits on the driver's seat 11 in the cab 10 and operates the travel lever and pedal device (not shown) to drive the hydraulic excavator 1 to the work site. Then, the operator operates the operating lever device 12 at the work site to rotate the upper rotating body 3 while using the working device 4 to perform excavation work such as sand and soil.

[0045] When the hydraulic excavator 1 is in operation, the cooling fan 8A is rotated by the engine 8, and a large amount of outside air flows into the heat exchanger chamber 23 through the vents 17C, 17D, and 17E of the right rear exterior cover 17. The outside air becomes cooling air and is supplied to the radiator 21A and the oil cooler 21B of the heat exchanger 21, so that the engine cooling water and the hydraulic oil can be cooled.

[0046] On the other hand, when the hydraulic excavator 1 is in operation, in order to improve the living environment in the cab 10, the air conditioner 24 is operated to supply conditioned air to the cab 10. In this case, when the air conditioner 24 is switched to the outside air side, the air in the heat exchanger chamber 23 (outside air) flows from the filter box 26 into the air conditioner 24 through the outside air introduction duct 25. Thus, the air conditioner 24 supplies the conditioned air adjusted to a desired temperature to the cab 10.

[0047] Here, in the hydraulic excavator 1 of the present embodiment, the outside air intake port 25B of the outside air intake duct 25 is opened toward the upstream side of the flow F of the cooling air in the heat exchanger chamber 23 into which the cooling air flows. Since a large amount of cooling air flows into the heat exchanger chamber 23 due to the rotation of the cooling fan 8A, a part of the cooling air is guided to the outside air intake port 25B arranged in the heat exchanger chamber 23. Thus, the outside air can be efficiently introduced into the air conditioner 24 through the outside air intake duct 25.

[0048] Furthermore, the amount of outside air sucked by the air conditioner 24 is smaller than the flow rate of cooling air supplied to the heat exchanger 21 by the cooling fan 8A. Therefore, even if dust is scattered around the operating hydraulic excavator 1 and mixed with the outside air flowing into the heat exchanger chamber 23, most of the dust will flow toward the heat exchanger 21. Therefore, it is possible to suppress the dust from intruding into the air conditioner 24 through the outside air introduction duct 25.

[0049] In addition, the outside air intake port 25B of the outside air introduction duct 25 opens in the heat exchanger chamber 23 which is isolated from the outside when the right rear exterior cover 17 is closed. Therefore, even when a large amount of dust is scattered around the hydraulic excavator 1, it is possible to suppress the dust from entering the heat exchanger chamber 23. As a result, the dust in the outside air introduced into the air conditioner 24 through the outside air introduction duct 25 can be further reduced, and clean outside air can be supplied to the air conditioner 24.

[0050] In addition, the dust filter 27 is installed at the external air inlet 25B of the external air introduction duct 25 via the filter box 26 in the heat exchanger chamber 23. Therefore, dust mixed in the external air introduced into the external air inlet 25B can be reliably captured by the dust filter 27. In addition, the dust intruding into the heat exchanger chamber 23 is reduced, so the clogging of the dust filter 27 can be suppressed, and the life of the dust filter 27 can be extended.

[0051] In addition, the outside air inlet 25B of the outside air introduction duct 25 to which the filter box 26 is installed is arranged above the heat exchanger 21 in the heat exchanger chamber 23. Therefore, it is possible to prevent the cooling air supplied to the heat exchanger 21 through the vents 17C, 17D, and 17E of the right rear exterior cover 17 from directly flowing into the outside air introduction duct 25. As a result, it is possible to prevent dust mixed in the cooling air from intruding into the air conditioning device 24 through the outside air introduction duct 25. Moreover, when the cockpit 10 is heated by the air conditioning device 24, the warm air retained above the heat exchanger 21 can be guided to the air conditioning device 24 through the outside air introduction duct 25. As a result, the cockpit 10 can be efficiently heated.

[0052] In addition, the outside air inlet 25B of the outside air introduction duct 25 is arranged above the vent 17C arranged at the uppermost side among the three vents 17C, 17D, and 17E provided in the right rear exterior cover 17 that covers the heat exchanger chamber 23 in an openable and closable manner. Thus, even if dust is mixed in the cooling air that flows into the heat exchanger chamber 23 through the vents 17C, 17D, and 17E by the rotation of the cooling fan 8A, it is possible to suppress the dust from intruding into the outside air introduction duct 25 through the outside air inlet 25B.

[0053] Thus, the hydraulic excavator 1 of the embodiment includes: a cooling fan 8A that generates cooling air; a heat exchanger 21 that uses the cooling air supplied from the cooling fan 8A to cool the fluid; a right rear exterior cover 17 that covers the cooling fan 8A and the heat exchanger 21 to form a heat exchanger chamber 23 and has vents 17C, 17D, and 17E for circulating the cooling air with the outside of the vehicle body; a cab 10 that forms a cab; an air conditioning device 24 that supplies conditioned air into the cab 10; and an external air introduction duct 25 that has an external air inlet 25B and is used to introduce external air taken in from the external air inlet 25B into the air conditioning device 24, the external air inlet 25B being disposed in the heat exchanger chamber 23 and configured to open toward the upstream side of the flow of the cooling air.

[0054] According to this structure, in the heat exchanger chamber 23 into which a large amount of cooling air flows by the cooling fan 8A, a part of the cooling air is guided to the outside air intake port 25B, thereby enabling the outside air to be efficiently supplied to the air conditioner 24 through the outside air introduction duct 25. In this case, the amount of outside air sucked by the air conditioner 24 is smaller than the flow rate of the cooling air supplied to the heat exchanger 21 by the cooling fan 8A. Therefore, even if dust scattered around the hydraulic excavator 1 is mixed with the cooling air, since most of the dust flows to the heat exchanger 21, it is possible to suppress the dust from entering the air conditioner 24 through the outside air introduction duct 25.

[0055] In the embodiment, the air conditioning device 24 is provided in the cockpit 10, and the outside air inlet 25B of the outside air introduction duct 25 is arranged above the heat exchanger 21 in the heat exchanger chamber 23. According to this structure, when the cockpit 10 is heated by the air conditioning device 24, the warm air stagnating in the heat exchanger chamber 23 where the heat exchanger 21 that has reached a high temperature is arranged and above the heat exchanger 21 can be guided to the air conditioning device 24 through the outside air introduction duct 25, so that the cockpit 10 can be efficiently heated.

[0056] In the embodiment, a dust filter 27 is installed at the external air intake port 25B of the external air introduction duct 25, and the dust filter 27 is arranged above the upper ends of the vents 17C, 17D, and 17E provided in the right rear exterior cover 17. According to this structure, dust and foreign matter mixed in the cooling air are captured by the dust filter 27, so it is possible to suppress the dust and foreign matter from invading the external air introduction duct 25 through the external air intake port 25B. In addition, the external air intake port 25B is provided above the flow path of the cooling air between the cooling fan 8A and the vents 17C, 17D, and 17E. Therefore, it is possible to suppress the cooling air that flows into the heat exchanger chamber 23 through the vents 17C, 17D, and 17E by the rotation of the cooling fan 8A and flows toward the heat exchanger 21 from directly flowing into the external air intake port 25B. That is, even if dust or foreign matter is mixed in the cooling air, the dust or foreign matter collected by the dust filter 27 can be relatively reduced compared to the case where the external air intake port 25B is provided in the cooling air flow path between the cooling fan 8A and the vents 17C, 17D, 17E, or the case where the external air intake port 25B is provided below the cooling air flow path where dust or foreign matter is easily accumulated. As a result, the clogging of the dust filter 27 can be suppressed, and the period during which the dust filter 27 needs to be replaced can be extended.

[0057] In addition, in the embodiment, the following case is illustrated, that is, the filter box 26 is installed at the external air intake port 25B of the external air introduction duct 25, and the dust filter 27 is installed at the air intake port 26B of the filter box 26. However, the present invention is not limited to this, and for example, the following structure may be adopted, that is, without using the filter box 26, the dust filter is directly installed at the external air intake port 25B of the external air introduction duct 25.

[0058] In the embodiment, a small hydraulic excavator 1 having a crawler-type lower traveling body 2 is exemplified as a construction machine. However, the present invention is not limited thereto and can be widely applied to construction machines such as standard hydraulic excavators, wheeled hydraulic excavators, and hydraulic cranes.

[0059] Explanation of symbols

[0060] 1—hydraulic excavator (construction machinery), 2—lower traveling body (body), 3—upper rotating body (body), 4—working device, 8A—cooling fan, 10—operating cabin, 21—heat exchanger, 23—heat exchanger chamber, 24—air conditioning device, 25—external air introduction duct (duct), 25B—external air intake, 17—right rear exterior cover (external cover), 17C, 17D, 17E—air vents, 27—dust filter.

Claims

1. A construction machine comprising: a cooling fan that generates cooling air; a heat exchanger for cooling a fluid using the cooling air supplied from the cooling fan; an exterior cover covering the cooling fan and the heat exchanger to form a heat exchanger chamber and having a vent for allowing the cooling air to flow to the outside of the vehicle body; a cockpit, which forms the pilothouse; an air conditioning device that supplies conditioned air into the cockpit; and a duct having an external air intake port and used to introduce the external air taken in from the external air intake port into the air conditioning device, The construction machinery is characterized in that The outside air intake port is provided in the heat exchanger chamber and is arranged to open toward an upstream side of a flow of the cooling air.

2. The construction machinery according to claim 1, characterized in that: The air conditioning device is arranged in the cockpit. The outside air intake port of the duct is arranged above the heat exchanger in the heat exchanger chamber.

3. The construction machine according to claim 1, characterized in that: A dust filter is mounted on the outside air intake port of the duct, and the dust filter is disposed above an upper end of the vent provided in the exterior cover.

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