Construction machine

An upper revolving structure (3) includes a revolving frame (5), a floor member (9) which is provided on the revolving frame (5) and a front side of which serves as a footrest section (11) on which an operator rests his or her feet, a cab box (17) which forms an operating room (18) above the floor member (9), and an indoor unit (23) disposed on the floor member (9) to supply sucked air as conditioned air. A lower surface (11B) side of the footrest section (11) of the floor member (9) is formed as a unit mounting surface (12), and, as for the indoor unit (23), a box body (24) is disposed on the lower side of the unit mounting surface (12) and, in this state, the box body (24) is mounted on the unit mounting surface (12) by means of a plurality of bolts (32).

TECHNICAL FIELD

The present invention relates to a construction machine such as a hydraulic excavator having an indoor unit on a floor member.

BACKGROUND ART

Generally, a hydraulic excavator as a construction machine is largely constituted by an automotive lower traveling structure, an upper revolving structure which is swingably mounted on the lower traveling structure, and a working mechanism liftably mounted on the front side of the upper revolving structure.

The upper revolving structure is largely constituted by a revolving frame which forms a support structure; an engine provided on the rear side of the revolving frame to drive a hydraulic pump; a floor member provided on the revolving frame by being located on the front side of the engine, a rear side of which serves as an operator's seat mounting section for mounting an operator's seat, and a front side of which serves as a footrest section on which an operator rests his or her feet; a cab box provided so as to cover the surroundings and the upper side of the floor member to form an operating room above the floor member; and an air conditioner for supplying conditioned air to the operating room so as to improve the working environment of the operating room.

Here, the air conditioner is formed by connecting an outdoor unit on the engine side and an indoor unit on the floor member side by means of refrigerant pipes. The outdoor unit on the engine side is configured by including a condenser which is located midway in the refrigerant pipes and cools the refrigerant by the cooling air generated by a cooling fan of the engine. The indoor unit on the floor member side is configured by including a fan for generating a flow of air directed toward the operating room, as well as an evaporator which effects heat exchange at the time of expansion of the compressed refrigerant and cools the air generated by the fan and/or a heater core for heating through which engine cooling water circulates.

Meanwhile, among hydraulic excavators, there are small-sized hydraulic excavators called mini excavators which are suitable for operation in narrow work sites and in this small-sized hydraulic excavator, the upper revolving structure is formed to be small so as to be able to revolve even in narrow places.

In the small-sized hydraulic excavator, since the operating room is narrow, the indoor unit is disposed at the operator's foot. Namely, a large opening is provided in a footrest section of a floor member, and a bottomed box-shaped tray which is downwardly recessed is mounted in this opening. The indoor unit is disposed in this tray, and the upper side of the indoor unit is arranged to be covered with a cover (Patent Document 1).

PRIOR ART DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

Incidentally, the hydraulic excavator is such as to be operated on waste land and muddy places, and the interior of the operating room becomes soiled as mud and the like attached to the operator's shoes come off, so that the interior of the operating room is sometimes washed with water. In this case, with the hydraulic excavator according to Patent Document 1, the box-shaped tray is provided in the opening of the footrest section of the floor member, and the indoor unit is accommodated in this tray. For this reason, a seal member must be provided between the footrest section and the cover in order that water does not enter the indoor unit even when the interior of the operating room is washed with water. Moreover, with the hydraulic excavator according to Patent Document 1, in order to dispose the indoor unit, the opening is processed in the footrest section of the floor member, the box-shaped tray to be mounted in this opening is fabricated, and the cover for covering the upper side of the indoor unit is fabricated, so that there is a problem in that the number of parts and man-hour for processing increase.

In view of the above-discussed problems with the prior art, it is an object of the present invention to provide a construction machine which makes it possible to dispose the indoor unit on the footrest section of the floor member with a small number of parts and less man-hour while water is prevented from entering the indoor unit at the time of washing the interior of the operating room with water.

(1) A construction machine in accordance with the present invention includes an automotive lower traveling structure, an upper revolving structure which is swingably mounted on the lower traveling structure, and a working mechanism liftably mounted on the upper revolving structure, the upper revolving structure being provided with a revolving frame forming a support structure; a floor member which is provided on the revolving frame, a rear side of which serves as an operator's seat mounting section for mounting an operator's seat, and a front side of which serves as a footrest section on which an operator rests his or her feet; a cab box which is provided in such a manner as to cover surroundings and an upper side of the floor member to form an operating room above the floor member and which has on one side thereof a door which is opened and closed when the operator enters and exits; and an indoor unit which is disposed on the floor member and constitutes a part of an air conditioner for supplying sucked air into an interior of the operating room as conditioned air.

The characteristic of the construction adopted in the present invention to solve the above-described problems lies in that the footrest section has its lower surface side used as a unit mounting surface for mounting the indoor unit thereon, and the indoor unit is arranged to be disposed in a suspended state on the unit mounting surface by being mounted on the unit mounting surface by means of fastening members.

With this arrangement, the lower surface side of the footrest section of the floor member is used as the unit mounting surface, and the indoor unit is abutted against this unit mounting surface from below and in this state, the indoor unit is mounted on the unit mounting surface by means of the fastening members. In consequence, the indoor unit can be disposed in a suspended state on the lower surface (unit mounting surface) of the footrest section.

Accordingly, since the footrest section of the floor member is sufficient if the indoor unit can be mounted to the unit mounting surface of the lower surface side, it is unnecessary to additionally provide special processing or parts, so that the footrest section can be formed as a simple flat surface.

As a result, since it is unnecessary for an opening for disposing the indoor unit to be provided in the footrest section of the floor member, it is possible to reliably prevent water from entering the indoor unit at the time of washing the interior of the operating room with water, without needing to separately provide a seal member or the like. In consequence, at the time of washing the interior of the operating room with water, the cleaning operation can be performed efficiently since it is unnecessary to give extra consideration to the indoor unit being splashed with water. Furthermore, it is possible to reduce the number of parts such as the seal member, the tray, and the cover as well as man-hour for processing the footrest section.

(2) According to the present invention, a plurality of female screw holes are provided in the footrest section by being located in peripheries of the unit mounting surface, fastening member insertion holes are provided in the indoor unit at positions corresponding to the female screw holes, and the indoor unit is arranged to be fastened to the unit mounting surface as the fastening members inserted in the fastening member insertion holes are threadedly secured to the female screw holes.

With this arrangement, the indoor unit is abutted from below against the unit mounting surface on the lower surface side of the footrest section, and the female screw holes provided in the peripheries of the unit mounting surface of the footrest section and the fastening member insertion holes of the indoor unit are positioned. In this state, the fastening members are inserted in the fastening member insertion holes and are threadedly secured to the female screw holes. In consequence, the indoor unit can be simply mounted to the unit mounting surface by using the fastening members, and can be simply dismounted by loosening the fastening members.

(3) According to the present invention, the indoor unit is configured by including a box body constituted by a closed structure having a bottom surface, peripheral surfaces, and a top surface which form an outer shell thereof, a fan disposed in the box body to generate a flow of air, and an evaporator and/or a heater core disposed in the box body to condition air, and the indoor unit is mounted on the unit mounting surface in a state in which the top surface of the box body is opposed to the unit mounting surface of the footrest section.

With this construction, as the top surface of the box body having a closed structure which forms the outer shell of the indoor unit is opposed to the unit mounting surface of the footrest section, the indoor unit in this state can be mounted on the unit mounting surface in a suspended state.

(4) According to the present invention, the indoor unit is configured by including a box body of a frame-like structure whose upper side is opened and having a bottom surface and peripheral surfaces which form an outer shell thereof, a fan disposed in the box body to generate a flow of air, and an evaporator and/or a heater core disposed in the box body to condition air, and the unit mounting surface of the footrest section is able to form a closing surface which closes an upper side of the box body when the box body is mounted on the unit mounting surface.

With this arrangement, as the box body whose upper side is open is mounted on the unit mounting surface of the footrest section, the upper side of the box body can be closed by making use of the unit mounting surface as the closing surface. Accordingly, since the vertical dimension of the box body can be made small by the amount in which the top surface is omitted, the height dimension of the upper revolving structure can be reduced to a low level, making it possible to enhance stability during traveling and work operation. Meanwhile, the accommodating space on the lower side of the floor member above the revolving frame can be made large. Furthermore, at the time of performing inspection operation or repair operation of the indoor unit, by merely dismounting the indoor unit from the footrest section it is possible to inspect or repair the fan, the evaporator, the heater core, and the like inside it without needing to disassemble the box body.

(5) In the present invention, the box body in a plan view is formed in a rectangular shape extending in a left-right direction, air intake ports for admitting air are provided in the box body by being located on a side of the door of the cab box, and air outlet ports for discharging the conditioned air are provided in the box body by being located on an opposite side to the door, the evaporator and/or the heater core being arranged to be disposed between the air intake ports and the air outlet ports inside the box body.

With this arrangement, the rectangular box body extending in the left-right direction is able to admit air from the air intake ports provided on the door side of the cab box. The air admitted from the air intake ports can be regulated to a desired temperature by the evaporator and the heater core, and this conditioned air can be supplied to the operating room by being discharged from the air outlet ports disposed on the opposite side in the left-right direction to the door.

MODE FOR CARRYING OUT THE INVENTION

Hereafter, a construction machine which is applied to an embodiment of the present invention will be in detail explained with reference to the accompanying drawingsFIG. 1toFIG. 13, by taking a hydraulic excavator of cab specifications as an example.

FIGS. 1 to 9show a construction machine in accordance with a first embodiment. The characteristic of this embodiment lies in that the box body of the indoor unit is formed as a closed structure having a bottom surface, peripheral surfaces, and a top surface, and the indoor unit is arranged to be mounted in a state in which the top surface of the box body is opposed to a unit mounting surface of a footrest section.

InFIG. 1, designated at1is a hydraulic excavator of the cab specifications as a construction machine which is applied to this embodiment, and the hydraulic excavator1is a small-sized hydraulic excavator called a mini excavator which is suitable for operation in narrow work sites. The hydraulic excavator1is largely constituted by an automotive lower traveling structure2, an upper revolving structure3which is swingably mounted on the lower traveling structure2, and a working mechanism4provided on the front side in the front-rear direction of the upper revolving structure3to perform the excavating operation of earth and sand.

Here, as shown inFIG. 2, the upper revolving structure3has a width dimension in the left-right direction which is substantially equal to the vehicle width of the lower traveling structure2, and is formed in a substantially circular shape, as viewed from above, so as to be accommodated within an imaginary circle C having a revolving radius R with a revolving center O as a center. In consequence, the hydraulic excavator1is configured as a rear small turn type hydraulic excavator in which when the upper revolving structure3revolves on the lower traveling structure2about the revolving center O as a center, a rear surface of a below-described counterweight36is accommodated substantially within the vehicle width of the lower traveling structure2.

It should be noted that the aforementioned revolving radius R is defined by the distance from the revolving center O to the rear surface of the counterweight36, and the aforementioned imaginary circle C is a locus of the rear surface of the counterweight36when the upper revolving structure3revolves.

The upper revolving structure3is constituted by such as a revolving frame5, a floor member9, an operator's seat14, a cab box17, an indoor unit23, bolts32, an air conditioner duct33, and a counterweight36which will be described hereinafter.

The revolving frame5forms a support structure of the upper revolving structure3mounted on the lower traveling structure2. The working mechanism4is mounted swingably and liftably on the front side of the revolving frame5.

An engine6is mounted on the rear side of the revolving frame5, and the engine6is disposed in a transversely mounted state in which it extends, for example, in the left-right direction. A heat exchanger7is provided on the right side of the engine6in such a manner as to oppose a cooling fan6A, and a hydraulic pump8is disposed on the left hand side thereof. The heat exchanger7is configured by including such as a radiator7A connected to a water jacket6B for cooling the engine6, an oil cooler7B for cooling operating oil for driving various actuators, and a condenser21of a below-described outdoor unit20.

Indicated at9is the floor member provided on the revolving frame5nearer the left side. As shown inFIG. 3, this floor member9is tiltably supported at its front side position by the revolving frame5at its front side position and is supported at its rear side position on an upper portion of the below-described counterweight36. In consequence, the floor member9together with the operator's seat14, the cab box17, the indoor unit23, the air conditioner duct33, and the like can be tilted up (the state ofFIG. 3) and tilted down (the state ofFIG. 1) by using the front side position as a fulcrum. When the floor member9is tilted down, a below-described mounting plate10D is supported in a vibration isolated manner on the counterweight36. Here, as shown inFIGS. 4 to 7, the floor member9is largely constituted by an operator's seat mounting section10, a footrest section11, and a lever/pedal mounting section13which will be described hereinafter.

The operator's seat mounting section10is formed in a stepped shape by being located on the rear side of the floor member9, and the operator's seat mounting section10is for mounting the below-described operator's seat14thereon. This operator's seat mounting section10is largely constituted by a front plate10A extending upwardly from a rear portion of the footrest section11, a substantially flat placing plate10B extending rearwardly from an upper portion of the front plate10A to mount the operator's seat14thereon, a back plate10C extending upwardly from a rear portion of the placing plate10B, the mounting plate10D extending rearwardly from an upper portion of the back plate10C, and a left side plate10E extending rearwardly from the front plate10A along left-side edges of the placing plate10B and the back plate10C.

Here, an internal air filter (not shown) for removing dust in the internal air which is supplied to the below-described indoor unit23, for example, is provided on the front plate10A of the operator's seat mounting section10by being located on the front side of the operator's seat14. Correspondingly, internal air inlet ports10F for allowing the internal air to flow in toward the internal air filter is provided in front portions of the placing plate10B. Due to being provided in the placing plate10B, these internal air inlet ports10F are made difficult to suck in the cool air around the operator's feet, and cause the air which has been heated to some extent to be sucked in by the below-described indoor unit23, thereby making it possible to enhance the heating efficiency.

The footrest section11of the floor member9is for the operator seated in the operator's seat14to rest his or her feet thereon, and is provided on the front side of the operator's seat mounting section10. The footrest section11is formed as a substantially rectangular flat plate which is elongated in the left-right direction. Namely, the footrest section11has an upper surface11A on which the operator's feet rest and a lower surface11B on which the below-described indoor unit23is mounted.

Three outlet port mounting openings11C,11D, and11E, for example, are provided on the right end side of the footrest section11in such a manner as to extend in the front-rear direction. A front side air outlet port24J of a box body24of the indoor unit23, which allows conditioned air directed toward the front side of a below-described operating room18and toward the operator seated in the operator's seat14to flow out, is disposed at the outlet port mounting opening11C located on the front side among the three outlet port mounting openings11C,11D, and11E. A foot side air outlet port24K, which allows conditioned air directed toward the operator's feet to flow out, is disposed at the outlet port mounting opening11D located on the rear side of the outlet port mounting opening11C. Further, a rear side air outlet port24L, which allows conditioned air directed toward the rear side of the operating room18to flow out, is disposed at the outlet port mounting opening11E located on the left side of the outlet port mounting opening11D.

As shown in such asFIGS. 5 and 6, a plurality of female screw holes11F, in which the below-described bolts32for mounting the indoor unit23are threadedly secured, are provided at six locations in the upper surface11A of the footrest section11by being located in the surroundings of a below-described unit mounting surface12. These female screw holes11F at the six locations are arranged at positions corresponding to bolt through holes24G at six locations which are provided in the surroundings of the below-described box body24. Here, each of the female screw holes11F is formed by, for example, welding a weld nut to a through hole bored in the footrest section11.

It should be noted that the left end of the footrest section11, which is on a door17F side of the below-described cab box17, serves as a step-like footstep section11G for the operator to step on when getting into or out of the operating room18.

The unit mounting surface12is provided on the lower surface11B side of the footrest section11, and the below-described indoor unit23is mounted on this unit mounting surface12. Specifically, the unit mounting surface12is provided in a range in which the box body24of the indoor unit23abuts in the lower surface11B of the footrest section11, namely, in a range indicated by two-dot chain lines inFIG. 6. The indoor unit23is directly mounted on this unit mounting surface12in a suspended state such that the box body24is opposed thereto.

The lever/pedal mounting section13is provided on the front side of the footrest section11, and the lever/pedal mounting section13extends in the left-right direction along the front end of the footrest section11. As shown inFIG. 4, below-described operating levers/pedals16for traveling and the like are mounted on the lever/pedal mounting section13.

The operator's seat14is provided on the floor member9, and the operator's seat14is placed in a central position in the left-right direction of the placing plate10B for constituting the operator's seat mounting section10. This operator's seat14is for the operator to be seated therein when operating the hydraulic excavator1. As shown inFIG. 4, operating levers15for work operation for operating the working mechanism4and the like are disposed on both left and right hand sides of the operator's seat14. The operating levers/pedals16for traveling and the like, which are operated by manual operation or pedal operation when the lower traveling structure2is caused to travel, are provided on the lever/pedal mounting section13located in front of the operator's seat14.

The cab box17is provided on the floor member9, and the cab box17is for covering the surroundings and the upper side of the floor member9. The cab box17is formed into a box shape by a front panel17A, a rear panel17B, a left side panel17C, a right side panel17D, and a top panel17E, and its lower end portions are affixed to peripheral edges of the floor member9. In consequence, the cab box17forms above the floor member9the operating room18which serves as an occupying space for the operator.

The door17F is openably provided in the left side panel17C forming a side surface of the cab box17by being located close to a front side corresponding to the footrest section11of the floor member9. This door17F is for opening and closing an entrance way provided on the left side of the footrest section11.

Next, an air conditioner19which is provided on the upper revolving structure3to supply conditioned air into the operating room18will be explained.

Namely, designated at19is the air conditioner which is used in the first embodiment. As shown inFIG. 13, this air conditioner19is constituted by the outdoor unit20provided on the engine6side, the indoor unit23provided on the floor member9side, and refrigerant pipes30and hot water pipes31for connecting the outdoor unit20and the indoor unit23.

The outdoor unit20is provided on the engine6side, and the outdoor unit20is disposed on the front side of the radiator7A. This outdoor unit20is constituted by the condenser21which liquefies the vaporized refrigerant by cooling it, a receiver dry22which is provided on the downstream side of the condenser21and is adapted to separate the liquefied refrigerant into a gas and a liquid while temporarily storing the liquefied refrigerant, and the radiator7A of the heat exchanger7for supplying hot water into a below-described heater core27.

Designated at23is the indoor unit in accordance with the first embodiment for constituting the air conditioner19. As shown inFIG. 8, this indoor unit23is directly mounted in a suspended state on the unit mounting surface12provided on the lower surface11B side of the footrest section11of the floor member9. The indoor unit23together with the aforementioned outdoor unit20constitutes the air conditioner19. Here, the indoor unit23sucks in internal air inside the operating room18or external air outside the operating room18, converts it into conditioned air regulated to a desired temperature and humidity, and supplies it from the below-described air conditioner duct33into the operating room18.

As shown inFIG. 10, the indoor unit23is constituted by the box body24for forming an outer shell, a fan25which is provided on the upstream side within the box body24and delivers toward the air conditioner duct33the air sucked into the box body24, an evaporator26accommodated in the box body24by being located downstream of the fan25, the heater core27disposed downstream of the evaporator26, and a flow direction changing mechanism28located downstream of the heater core27and adapted to change over the supply direction of the conditioned air.

Here, the box body24of the indoor unit23is formed as a casing having a rectangular parallelepiped-shaped closed structure which, in a plan view, has a rectangular shape extending in the left-right direction, is hence elongated in the left-right direction, and is flattened in the vertical direction. Namely, the box body24is largely constituted by a rectangular bottom surface portion24A located at the bottom and extending in the left-right direction, a front surface portion24B, a rear surface portion24C, a left side surface portion24D, and a right side surface portion24E which form peripheral surfaces extending upwardly from peripheries of the bottom surface portion24A, and a rectangular top surface portion24F extending in the left-right direction to close upper ends of these side surface portions24B to24E.

The bolt through holes24G serving as fastening member insertion holes are formed at six locations corresponding to the six female screw holes11F of the footrest section11on the box body24, and the below-described bolts32are inserted into the respective bolt through holes24G. The top surface portion24F of the box body24opposes the unit mounting surface12formed in the lower surface11B of the footrest section11in a state of abutment against or close proximity to it.

The left side surface portion24D located on the door17F side of the cab box17is located on the upstream side in the flowing direction of air inside the box body24. This left side surface portion24D is provided with an air intake port24H for admitting air into the box body24.

Meanwhile, the front side air outlet port24J, the foot side air outlet port24K, and the rear side air outlet port24L for discharging the conditioned air from the box body24are provided on the downstream side of the box body24which is on the opposite side in the left-right direction to the door17F of the cab box17, namely, on the right end side of the top surface portion24F. The front side air outlet port24J, the foot side air outlet port24K, and the rear side air outlet port24L extend upwardly in frame shape so as to project upwardly of the upper surface11A of the footrest section11.

The front side air outlet port24J located on the front side of the top surface portion24F is for allowing the conditioned air directed toward the front side of the operating room18and the operator seated in the operator's seat14to flow out, and a below-described front side supply duct35A is connected thereto. The foot side air outlet port24K located on the rear side of the front side air outlet port24J is for allowing the conditioned air directed toward the operator's feet to flow out, and a below-described foot side supply duct35B is connected thereto. Further, the rear side air outlet port24L located on the left side of the foot side air outlet port24K is for allowing the conditioned air directed toward the rear side of the operator's seat14to flow out, and a below-described rear side supply duct35C is connected thereto.

The cooling fan25is provided on the upstream side (left side) in the box body24, and the fan25is for allowing the air admitted from the air intake port24H to be circulated toward the air outlet ports24J,24K, and24L.

The evaporator26is accommodated in the box body24, and the evaporator26is disposed in the vicinity of the downstream side (right side) of the fan25. This evaporator26is for cooling the air by utilizing vaporization heat at the time of evaporation of the refrigerant, and is connected to such as the condenser21and the receiver dry22of the outdoor unit through the below-described refrigerant pipes30.

The heater core27for heating is accommodated in the box body24, and the heater core27is disposed in the vicinity of the downstream side (right side) of the evaporator26. This heater core27is for heating the air by utilizing engine cooling water heated by the engine6, and is connected to the radiator7A through the below-described refrigerant pipes30.

The flow direction changing mechanism28is accommodated in the box body24by being located between the heater core27and the air outlet ports24J,24K, and24L. This flow direction changing mechanism28is for effecting a changeover among the air outlet ports24J,24K, and24L from which the conditioned air is supplied.

It should be noted that, as shown inFIGS. 7 and 9, an internal/external air changing mechanism29is mounted in the indoor unit23by being located in a left end portion of the box body24. This internal/external air changing mechanism29is for changing over the air to be sucked by the fan25between the internal air inside the operating room18and the external air outside it.

The refrigerant pipes30are for connecting the condenser21of the outdoor unit20and the evaporator26of the indoor unit23. The hot water pipes31are for connecting the radiator7A of the outdoor unit20and the heater core27of the indoor unit23. As shown inFIG. 3, these refrigerant pipes30and hot water pipes31are connected all the time while tilting up the floor member9and extend in such a manner as to turn back at a front side position of the revolving frame5so as not to hamper the maintenance operation.

Indicated at32are a plurality of, for example, six, bolts which form fastening members. As these bolts32are inserted into the respective bolt through holes24G of the box body24from below, and their distal end sides are threadedly secured to the female screw holes11F of the footrest section11, the indoor unit23can be mounted on the lower surface11B (unit mounting surface12) of the footrest section11.

The indoor unit23thus constructed is abutted from below against the unit mounting surface12formed in the lower surface11B of the footrest section11of the floor member9. In this state, the bolts32inserted in the respective bolt through holes24G of the box body24are threadedly secured to the female screw holes11F of the footrest section11. In consequence, the indoor unit23can be directly mounted on the unit mounting surface12in a suspended state by using the bolts32.

Indicated at33is the air conditioner duct (seeFIGS. 4 and 11) provided at the right end side of the footrest section11of the floor member9, and the air conditioner duct33is constituted by a duct cover34, the front side supply duct35A, the foot side supply duct35B, and the rear side supply duct35C. Here, the duct cover34is provided in such a manner as to extend from the right side toward the front side of the operator's seat14, a front side discharge port34A for discharging the conditioned air toward the front side of the operating room18is provided on its left surface side, and an operator's seat side discharge port34B for discharging the conditioned air toward the operator seated in the operator's seat14is provided on its upper side. A foot side discharge port34C for discharging the conditioned air toward the operator's feet is provided rearwardly of the front side discharge port34A. Further, a rear side discharge port (not shown) for discharging the conditioned air to the overall operating room18is provided on the rear side of the operator's seat14separately from the duct cover34.

Meanwhile, the front side supply duct35A of the air conditioner duct33is for guiding the conditioned air from the indoor unit23to the front side discharge port34A and the operator's seat side discharge port34B. The foot side supply duct35B is for guiding the conditioned air from the indoor unit23to the foot side discharge port34C. Further, the rear side supply duct35C is for guiding the conditioned air from the indoor unit23to the rear side discharge port.

Here, a proximal end portion of the front side supply duct35A for constituting the air conditioner duct33is mounted in an externally fitted state on the front side air outlet port24J of the box body24of the indoor unit23which projects upwardly from the outlet port mounting opening11C of the footrest section11. Similarly, a proximal end portion of the foot side supply duct35B is mounted in an externally fitted state on the foot side air outlet port24K of the box body24which projects upwardly from the outlet port mounting opening11D of the footrest section11. A proximal end portion of the rear side supply duct35C is mounted in an externally fitted state on the rear side air outlet port24L of the box body24which projects upwardly from the outlet port mounting opening11E of the footrest section11. Therefore, even when the footrest section11is washed with water, it is possible to prevent the cleaning water from entering the respective outlet ports24J,24K, and24L of the box body24.

It should be noted that indicated at36is the counterweight (seeFIGS. 2 and 3) provided on a rear portion of the revolving frame5, and the counterweight36is for keeping a weight balance with the working mechanism4. The counterweight36is formed in such a manner as to be curved in a circular arc shape so as to cover the engine6from behind. Further, the counterweight36constitutes a support structure for mounting the mounting plate10D of the operator's seat mounting section10for constituting the floor member9on the revolving frame5side.

The hydraulic excavator1in accordance with the first embodiment has the above-described construction, and its operation will be explained.

As the operator, who entered the operating room18and is seated in the operator's seat14, operates the operating levers/pedals16for traveling, the lower traveling structure2is caused to travel. Meanwhile, by operating the left and right operating levers15for work operation, the operator is able to operate the working mechanism4and the like to perform such as the operation of excavating earth and sand.

Here, during the above-described work operation, the indoor unit23of the air conditioner19is driven to improve the environment of the operating room18. At this time, the indoor unit23sucks in the air inside or outside the operating room18and cools this air by the evaporator26in the box body24or heats it by the heater core27therein to convert it into conditioned air. By selecting a supply direction by the flow direction changing mechanism28, it is possible to discharge the conditioned air to a desired location within the operating room18and regulate the temperature of the operating room18to an appropriate level.

Further, in cases where maintenance of the indoor unit23is performed, the indoor unit23can be exposed by tilting up the rear side of the floor member9together with such as the operator's seat14and the indoor unit23by using the front side as a fulcrum (seeFIG. 3). In this state, the indoor unit23can be dismounted by loosening the bolts32, thereby making it possible to perform the maintenance operation.

Thus, according to the first embodiment, the lower surface11B side of the footrest section11for forming the floor member9is used as the unit mounting surface12, and the box body24of the indoor unit23is abutted against this unit mounting surface12from below. In this state, the box body24of the indoor unit23is arranged to be mounted directly to the unit mounting surface12by means of the bolts32. In consequence, the indoor unit23can be mounted in a suspended state to the unit mounting surface12of the footrest section11by virtue of a simple mounting structure using the bolts32.

Accordingly, since the footrest section11of the floor member9is sufficient if the indoor unit23can be mounted to the unit mounting surface12on the lower surface11B side by means of the bolts32, it is unnecessary to additionally provide special processing or parts. Namely, the footrest section11can be formed as a simple flat surface-shaped plate in which the female screw holes11F are merely provided.

As a result, since the footrest section11of the floor member9is not provided with an opening for disposing the indoor unit23, it is unnecessary to provide a seal member for sealing this opening, and it is possible to reliably prevent water from entering the indoor unit23side at the time of washing the interior of the operating room18with water. In consequence, at the time of washing the interior of the operating room18with water, it is unnecessary to give extra consideration to the indoor unit23being splashed with water, so that the cleaning operation can be performed efficiently. Furthermore, it is possible to reduce the number of parts such as a seal member, a tray, and a cover as well as man-hour for processing the footrest section which have been required in the conventional art.

Meanwhile, the outlet port mounting openings11C,11D, and11E are provided in the footrest section11of the floor member9by being located in the recessed portion on the right side. The arrangement provided is such that the outlet ports24J,24K, and24L of the box body24of the indoor unit23are mounted at the respective outlet port mounting openings11C,11D, and11E in such a manner as to project to the upper side, and the supply ducts35A,35B, and35C of the air conditioner duct33are mounted in an externally fitted state to these outlet ports24J,24K, and24L. In consequence, even in the cases where the footrest section11is washed with water, it is possible to prevent cleaning water from entering the outlet ports24J,24K, and24L of the box body24, thereby making it possible to improve the service life and reliability of the air conditioner19.

Furthermore, the floor member9can be tilted up and down with respect to the revolving frame5by using the front side position as a tilting fulcrum. In consequence, in the state in which the floor member9is tilted up, the indoor unit23can be exposed to the outside, so that the mounting and dismounting operation, inspection operation, repair operation, and the like can be performed easily.

Next,FIGS. 14 and 15show a second embodiment of the present invention. The characteristic of this embodiment lies in an arrangement in which the box body of the indoor unit is formed as a frame-like structure whose upper side is open, and the unit mounting surface of the footrest section forms a closing surface which closes the upper side of the box body when the box body is mounted on the unit mounting surface. It should be noted that, in the second embodiment, the component elements that are identical to those of the foregoing first embodiment will be simply denoted by the same reference numerals to avoid repetitions of similar explanations.

InFIG. 14, indicated at41is a footrest section of the floor member in accordance with the second embodiment. In substantially the same way as the footrest section11in accordance with the above-described first embodiment, this footrest section41is formed as a substantially rectangular flat plate which is elongated in the left-right direction, and the footrest section41has an upper surface41A on which the operator rests his or her feet and a lower surface41B on which a below-described indoor unit43is mounted. A plurality of (only two are shown) female screw holes41C, in which the bolts32for mounting the indoor unit43are threadedly secured, are provided in the upper surface41A of the footrest section41.

Here, indicated at42is a unit mounting surface which is provided on the lower surface41B side of the footrest section41, and this unit mounting surface42forms a closing surface which closes the upper surface of a box body44of the below-described indoor unit43. Specifically, the box body44of the indoor unit43can be directly mounted on the unit mounting surface42in a suspended state and in this mounted state, the unit mounting surface42closes the upper surface of the box body44.

Designated at43is the indoor unit in accordance with the second embodiment which is provided on the footrest section41. As shown inFIG. 15, this indoor unit43is largely constituted by the box body44for forming an outer shell, as well as the fan25, the evaporator26, the heater core27, and the flow direction changing mechanism28which are provided in the box body44.

The box body44in accordance with the second embodiment is formed by a rectangular bottom surface portion44A extending in the left-right direction, as well as a front surface portion44B, a rear surface portion44C, a left side surface portion44D, and a right side surface portion44E which form peripheral surfaces extending upwardly from peripheries of the bottom surface portion44A. Accordingly, the box body44is formed as a bottomed and top-open frame-like structure (casing) having a rectangular parallelepiped shape which, as a whole, is elongated in the left-right direction and is flattened in the vertical direction and whose upper side is open. Bolt through holes44F serving as fastening member insertion holes are formed on the box body44at positions corresponding to the respective female screw holes41C of the footrest section41, and the bolts32are inserted in the respective bolt through holes44F.

An air intake port44G for admitting air into the box body44is provided in the left side surface portion44D located on the upstream side which is the door17F side of the cab box17. Meanwhile, a front side air outlet port44H, a foot side air outlet port44J, and a rear side air outlet port44K are provided in an upper portion on the right side which is the downstream side of the box body44.

The front side air outlet port44H located on the front side is for allowing the conditioned air directed toward the front side of the operating room18and the operator seated in the operator's seat14to flow out, and the front side supply duct35A is connected to the front side air outlet port44H with the footrest section41sandwiched therebetween. The foot side air outlet port44J located on the rear side of the front side air outlet port44H is for allowing the conditioned air directed toward the operator's feet to flow out, and the foot side supply duct35B is connected to the foot side air outlet port44J with the footrest section41sandwiched therebetween. Further, the rear side air outlet port44K located on the left side of the foot side air outlet port44J is for allowing the conditioned air directed toward the rear side of the operator's seat14to flow out, and the rear side supply duct35C is connected to the rear side air outlet port44K with the footrest section41sandwiched therebetween.

Here, although the upper surface of the box body44is open, the box body44is formed in a frame-like structure by making use of the unit mounting surface42of the footrest section41as its top surface portion. In consequence, the box body44can be formed to be small in its vertical dimension by the amount in which its top surface portion is omitted. Moreover, by merely dismounting the box body44from the footrest section41, it is possible to perform inspection operation and repair operation of the fan25, the evaporator26, the heater core27, and the like therein.

As for the indoor unit43in accordance with the second embodiment thus constructed, its box body44is abutted from below against the unit mounting surface42of the footrest section41. In this state, the bolts32inserted in the respective bolt through holes44F of the box body44are threadedly secured to the female screw holes41C of the footrest section41. As a result, the indoor unit43can be directly mounted on the unit mounting surface42in a suspended state by using the bolts32. In this state, the upper opening of the box body44can be closed by the unit mounting surface42(footrest section41).

As such, also with the second embodiment thus constructed, it is possible to obtain substantially similar operational effects to those of the above-described first embodiment. In particular, in the second embodiment, the box body44of the indoor unit43is formed as a bottomed container with its upper side open by the bottom surface portion44A as well as the front surface portion44B, the rear surface portion44C, the left side surface portion44D, and the right side surface portion44E for forming the peripheral surfaces, and this box body44is arranged to be mounted on the unit mounting surface42of the footrest section41. In consequence, the indoor unit43is able to make use of the unit mounting surface42of the footrest section41as the top surface portion of the box body44.

As a result, since the height dimension of the indoor unit43(box body44) can be made small by the amount in which the top surface portion is omitted, the height dimension of the upper revolving structure3can be reduced to a low level, making it possible to enhance stability during traveling and work operation. In addition, the accommodating space on the lower side of the floor member9above the revolving frame5can be made large, so that mounted equipment such as control valves can be disposed efficiently therein. Furthermore, at the time of performing inspection operation or repair operation of the indoor unit43, by merely dismounting the indoor unit43from the footrest section41it is possible to inspect or repair the fan25, the evaporator26, the heater core27, and the like therein without needing to disassemble the box body44, thereby making it possible improve the operational efficiency.

It should be noted that, in the first embodiment, it is explained by citing as an example the case in which both the evaporator26for cooling the air and the heater core27for heating the air are provided in the box body24of the indoor unit23. However, the present invention is not limited to the same, and, for example, in a hydraulic excavator which is used in work sites where the air temperature is low, only the heater core may be provided by omitting the evaporator so as to provide heating exclusively. On the other hand, in a hydraulic excavator which is used in work sites where the air temperature is high, only the evaporator may be provided by omitting the heater core so as to provide cooling exclusively. This arrangement can similarly be applied to the second embodiment as well.

Meanwhile, in the first embodiment, the female screw holes11F of the footrest section11and the bolt through holes24G of the box body24are respectively provided at six locations, and the box body24is arranged to be mounted on the footrest section11by means of the six bolts32. However, the present invention is not limited to the same, and, for example, the female screw holes11F of the footrest section11and the bolt through holes24G of the box body24may be respectively provided at not more than five locations or not less than seven locations, and the box body24may be arranged to be mounted on the footrest section11by means of bolts32in a number corresponding thereto. This arrangement can similarly be applied to the second embodiment as well.

Furthermore, in the embodiment, it is explained by citing as an example of the hydraulic excavator1of cab specifications having the crawler type lower traveling structure2as the construction machine. However, the present invention is not limited to the same, and may be applied to a hydraulic excavator or the like having, for example, a wheel type lower traveling structure.

DESCRIPTION OF REFERENCE NUMERALS