[Title of Invention]

AIR-CONDITIONING UNIT FOR THE CAB OF A CONSTRUCTION MACHINE

[Technical Field]

[0001] The present invention relates to a construction machine which has a cab incorporating an air conditioner and an equipment housing chamber disposed behind the cab, and in which one side wall of the cab is configured to have an outside air inlet provided with a filter and a cover member covering the outside air inlet.

[Background Art]

[0002] PTL 1 described below discloses a construction machine that has an outside air introduction part for

introducing outside air into an air conditioner inside a cab. The outside air introduction part has a filter for removing dust from the outside air introduced into the air conditioner, an openable/closeable cover that faces the outside of the filter and is provided with an outside air introduction hole for introducing the outside air, and waterproofing members provided between the cover and the filter so as to face each other. The waterproofing members are each provided with a through-hole for introducing the outside air to a position that is away from a region facing the filter. The

waterproofing members are each provided in a linear flow path for the outside air that is introduced to the inside through the outside air introduction hole. According to the construction machine disclosed in PTL 1, the waterproofing members block the water that flows in through the outside air introduction hole of the cover when the construction machine is washed or exposed to the weather, preventing the filter from direct exposure to water.

[Citation List]

[Patent Literature]

[0003]

[PTL 1] Japanese Patent No. 5415228

[Summary of Invention]

[Technical Problem]

[0004] However, the construction machine disclosed in PTL 1 is likely to cause early clogging of the filter because the outside air introduction hole of the cover is provided on an outer surface of the cab and therefore the outside air

containing a large amount of powder dust is introduced

directly into the outside air introduction hole from the outside air introduction hole in a construction site or the like having a large amount of powder dust.

[0005] The present invention was contrived in view of the foregoing circumstances, and a main technical object thereof is to provide a construction machine that curbs the entry of powder dust into a filter that is attached to an outside air inlet of an air conditioner.

[Solution to Problem] [0006] The present invention provides a construction machine for solving the foregoing technical problems, the construction machine including: a cab incorporating an air conditioner; and an equipment housing chamber disposed behind the cab, one side wall of the cab being configured to have an outside air inlet provided with a filter and a cover member covering the outside air inlet, wherein the cover member defines an outside air introduction path that extends from an inlet communicating with the inside of the equipment housing chamber to an outlet facing the outside air inlet, and

accordingly outside air is introduced from the equipment housing chamber to the air conditioner through the outside air introduction path and the filter.

[0007] It is preferred that the cover member have a hollow structure formed by an inner plate and an outer plate disposed in a width direction with a space therebetween and a

connecting plate connecting an outer rim of the inner plate and an outer rim of the outer plate to each other, and that the outside air introduction path be defined by the inside of the hollow cover member. It is preferred that the inner plate extend rearward past a rear end of the cab, that the outer plate extend rearward past a rear end of the inner plate, and that the inlet be defined between a rear end portion of the inner plate and a rear end portion of the outer plate. It is also preferred that a front end portion of the cover member extend forward past the outside air inlet, that an opening facing the outside air inlet be formed on the front end side of the inner plate, and that the outlet be defined by the opening. Moreover, it is preferred that the cover member be configured by a cover plate extending rearward past a rear end of the cab, first sealing means disposed between the cover plate and the one side wall at a section in front of the outside air inlet, above the outside air inlet, and below the outside air inlet, and second sealing means disposed along a rear edge and an upper edge of the outside air inlet, and between the cover plate and the one side wall.

[Advantageous Effects of Invention]

[0008] According to the construction machine provided by the present invention, because the cover member defines the outside air introduction path that extends from the inlet communicated with the inside of the equipment housing chamber to the outlet facing the outside air inlet, the entry of powder dust to the filter can be curbed by introducing outside air from the equipment housing chamber having a relatively small amount of powder dust to the air conditioner through the outside air introduction path and the filter, even in a working site having a large amount of powder dust.

[Brief Description of Drawings]

[0009]

[Fig. .1] Fig. 1 is a side view of a hydraulic shovel according to a first embodiment of the present invention.

[Fig. 2]

Fig. 2 is a side view of an upper slewing body shown in Fig. 1.

[Fig. 3]

Fig. 3 is a cross-sectional diagram taken along the direction of A-A of Fig. 2.

[Fig. 4]

Fig. 4 is a side view of the upper slewing body without a decorative cover shown in Fig. 2.

[Fig. 5]

Fig. 5 is a side view of the upper slewing body according to a second embodiment of the present invention.

[Fig. 6]

Fig. 6 is a cross-sectional diagram taken along the direction of B-B of Fig. 5.

[Description of Embodiments]

[0010] First and second embodiments of a construction machine configured according to the present invention are described hereinafter in detail with an example of a hydraulic shovel, which is a typical construction machine, and with reference to the accompanying drawings. [0011] The first embodiment of the construction machine according to the present invention is described first. As shown in Fig. 1, a hydraulic shovel, the entirety of which is shown by reference numeral 2, is configured roughly by a self- propelled lower traveling body 4, an upper slewing body 6 that is mounted on the lower traveling body 4 so as to be able to slew freely, and a working arm device 8 that is connected to the upper slewing body 6 so as to be able to move up and down. Excavation of sediment and the like can be accomplished by moving the working arm device 8 of the hydraulic shovel 2 up and down and allowing the upper slewing body 6 of the same to slew with respect to the lower traveling body 4.

[0012] The upper slewing body 6 has a slewing frame 10 configuring the frame structure, wherein on the slewing frame 10 are disposed a cab 12 for boarding an operator, an

equipment housing chamber 14 for housing various pieces of equipment such as the engine and a heat exchanger for cooling the engine cooling water, a counterweight 16 for balancing the load with respect to the working arm device 8, and the like. The cab 12 is disposed on the front left-hand side of the slewing frame 10, the equipment housing chamber 14 is disposed behind the cab 12, and the counterweight 16 is disposed behind the' equipment housing chamber 14. Note that the front-back direction and the width direction that are described in the present specification are equivalent to the front-back direction and the width direction in relation to the operator sitting in the cab 12 shown in Fig. 1.

[0013] The present embodiment is now described with

reference to Fig. 2. The cab 12 is overall in the shape of a rectangular cuboid and incorporates an air conditioner 18 in its lower back. On a left side surface of the cab 12, a front left support 20 is provided upright at a front end, a back left support 22 is provided upright at a rear end, and a middle left support 24 is provided upright between the front left support 20 and the back left support 22. The front left support 20, the back left support 22, and the middle left support 24 are each formed from a steel pipe. A door 26 is disposed between the front left support 20 and the middle left support 24. The door 26 is supported by the middle left support 24 so as to be opened/closed on a pair of upper and lower hinges 28, and can be opened to the outside of the cab 12. The door 26 is configured roughly by a frame material 26a made of steel, an upper glass window 26b disposed in an upper part of the frame material 26a, and a lower glass window 26c disposed below the upper glass window 26b. A rear glass window 30 is disposed between the middle left support -24 and the back left support 22, and a decorative cover 32 made of suitable metal or resin is disposed below the rear glass window 30. The decorative cover 32 extends rearward past the rear end of the cab 12, and a rear end portion of the

decorative cover 32 is bent inward in the width direction. [0014] The present embodiment is now described with reference to Figs. 3 and 4. On the inside of the decorative cover 32, a left side wall 34 formed from a steel plate is connected to the middle left support 24 and the back left support 22. An outside air inlet 34a in the shape of a square tube is formed in the left side wall 34. The outside air inlet 34a is connected to the air conditioner 18 by a duct 36. A filter 38, shaped into a flat rectangular cuboid to match the shape of the outside air inlet 34a, is installed

detachably in the outside air inlet 34a. The filter 38 is configured to remove dust from the outside air introduced into the air conditioner 18.

[0015] A cover member 40 for covering the outside air inlet 34a is disposed between the decorative cover 32 and the left side wall 34. The cover member 40 defines an outside air introduction path that extends from an inlet communicated with the inside of the equipment housing chamber 14 to an outlet facing the outside air inlet 34a, and accordingly outside air is introduced from the equipment housing chamber 14 into the air conditioner 18 through the outside air introduction path, the filter 38, and the duct 36.

[0016] The cover member 40 has an inner plate 42 and an outer plate 44, which are disposed in the width direction with a space therebetween, and a connecting plate 46 connecting an outer rim of the inner plate 42 and an outer rim of the outer plate 44 to each other. The cover member 40 is made of suitable metal or resin and shaped into a hollow, and the inside thereof defines the outside air introduction path. The inner plate 42 extends rearward past the rear end of the cab 12, and the outer plate 44 extends rearward past a rear end of the inner plate 42. A gap between a rear end portion of the inner plate 42 and a rear end portion of the outer plate 44 is located between the rear end of the cab 12 and a front end of a left side surface cover 48 of the equipment housing chamber 14, which is described hereinafter, and thereby defines the inlet of the outside air introduction path communicated with the inside of the equipment housing chamber 14. In addition, a front end portion of the cover member 40 extends forward past the outside air inlet 34a, and a rectangular opening 42a facing the outside air inlet 34a is formed on the front end side of the inner plate 42. This opening 42a defines the outlet of the outside air introduction path.

[0017] The equipment housing chamber 14 configures the frame structure with a plurality of steel supports and a plurality of steel beams, wherein the front surface, both side surfaces, and the upper surface of the equipment housing chamber 14 are defined by covers 48 (only the left side surface is shown) , and the back surface of the same is defined by the counterweight 16. The equipment housing chamber 14 is defined behind the cab 12 by a back surface plate 50 connected to the back left support 22 of the cab 12. Therefore, there is no cover provided behind the cab 12 to define the equipment housing chamber 14. The inside and the outside of the equipment housing chamber 14 are communicated with each other by openings formed in the cover 48, e.g., a plurality of openings 48a that are formed in a rear portion of the left side surface cover 48 as flow paths through which outside air flows into the heat exchanger.

[0018] The effects of the foregoing first embodiment of the construction machine according to the present invention shown in Figs. 1 to 4 are now described. In the first embodiment, because the cover member 40 defines the outside air

introduction path that extends from the inlet communicated with the inside of the equipment housing chamber 14 to the outlet facing the outside air inlet 34a, outside air is introduced from the equipment housing chamber 14 having a relatively small amount of powder dust to the air conditioner 18 through the outside air introduction path 40, the filter 38, and the duct 36 even in a working site having a large amount of powder dust, curbing the entry of powder dust to the filter 38. As a result, early clogging of the filter 38 can be prevented.

[0019] The second embodiment of the construction machine according to the present invention is described next with reference to Figs. 5 and 6. Note that the components and reference numerals same as those of the foregoing first embodiment are used in the second embodiment; thus, the overlapping descriptions are omitted accordingly. [0020] A cover plate 52 for covering the outside air inlet 34a is disposed below the rear glass window 30. The cover plate 52 has a flat portion 52a extending planarly past the rear end of the cab 12, a bent portion 52b that is bent inward in the width direction at a rear end of the flat portion 52a, and a rim portion 52c that extends obliquely inward in the width direction from an outer rim other than the rear end of the flat portion 52a and then extends substantially parallel to the flat portion 52a. The cover plate 52 is made of suitable metal, resin, or the like. The bent portion 52b is located between the rear end of the cab 12 and the front end of the left side surface cover 48. Furthermore, first sealing means 54 for sealing between the cover plate 52 and the left side wall 34 of the cab 12 is disposed between the cover plate 52 and the left side wall 34, at a section in front of the outside air inlet 34a, above the outside air inlet 34a, and below the outside air inlet 34a, i.e., a section corresponding to the rim portion 52c. Accordingly, the inlet of the outside air introduction path communicated with the inside of the equipment housing chamber 14 is defined. In addition, second sealing means 56 for sealing between the cover plate 52 and the left side wall 34 of the cab 12 is disposed along a rear edge and an upper edge of the outside air inlet 34a, between the cover plate 52 and the left side wall 34. Accordingly, the outlet facing the outside air inlet 34a is defined - between the cover plate 52 and the left side wall 34, and a path that circumvents the second sealing means 56 is defined as the outside air introduction path between an inlet and an outlet of the outside air inlet. The first and second sealing means 54 and 56 are made of an elastic material such as rubber.

[0021] The effects of the foregoing second embodiment of the construction machine according to the present invention shown in Figs. 5 and 6 are now described. In the second embodiment, the outside air introduction path that extends from the inlet communicated with the inside of the equipment housing chamber 14 to the outlet facing the outside air inlet 34a is defined by the cover plate 52 extending rearward past the rear end of the cab 12, the first sealing means 54 for sealing between the cover plate 52 and the left side wall 34, which is disposed at the section in front of the outside air inlet 34a, above the outside air inlet 34a, and below the outside air inlet 34a, and the second sealing means 56 disposed along the rear edge and the upper edge of the outside air inlet 34a, between the cover plate 52 and the left side wall 34. Therefore, outside air is introduced from the equipment housing chamber 14 having a relatively small amount of powder dust to the air conditioner 18 through the outside air introduction path 40, the filter 38, and the duct 36 even in a working site having a large amount of powder dust, curbing the entry of powder dust to the filter 38. As a result, early clogging of the filter 38 can be prevented.

Also in the second embodiment, . even when the outside air introduced from the equipment housing chamber 14 is mixed with powder dust, the second sealing means 56 for sealing between the cover plate 52 and the left side wall 34, which is

disposed along the rear edge and upper edge of the outside air inlet 34a, can separate the powder dust from the outside air when the outside air circumvents the second sealing means 56 and enters the outside air inlet 34a. Therefore, the entry of powder dust to the filter 38 can be further curbed.

[Reference Signs List]

[0022]

2 Hydraulic shovel (construction machine)

12 Cab

14 Equipment housing chamber

18 Air conditioner

34 Left side wall (one side wall)

34a Outside air inlet

38 Filter

40 Cover member (first embodiment)

42 Inner plate

44 Outer plate

46 Connecting plate

52 Cover plate (second embodiment)

52a Flat portion

52b Bent portion

52c Rim portion First sealing means Second sealing means