Sound proof box for an engine-driven work machine

A cooling air introduction path is formed in a base of a sound proof case of an engine-driven work machine. The base is divided into upper and lower portions, and a space in the upper portion is divided by a separation wall and arranged below an air discharging chamber. The upper part of one space is covered with a arranging plate, a partition wall is erected on the arranging plate, and a cooling air introduction port is provided between the partition wall and the separation wall to provide an engine chamber and one space are communicated, a hole is provided in the plate below the chamber, and one space and the space in the lower portion are communicated and located below the chamber. A cooling air intake port is provided on lateral walls of the lower portion to communicate the space inside the lower portion with the outside of the machine.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sound proof box for an engine-driven work machine (service machine) such as a compressor or generator which is equipped with an engine as a driving source, and more particularly to a sound proof box for an engine-driven work machine characterized in a structure of a cooling air introduction flow path provided in the sound proof box.

2. Description of the Related Art

An engine-driven work machine such as a compressor or generator which is provided with an engine as a driving source is usually configured as a sound proof work machine that prevents noise during operation from leaking out of the machine and is packaged by housing constituent equipment such as an engine or a work machine main body in a sound proof box in consideration of the convenience for transportation and installation.

Configurational examples of a sound proof box310for such an engine-driven work machine300are shown inFIGS.7and8.

The sound proof box310shown inFIGS.7and8is composed of a plan-view rectangular base320on which to arrange constituent equipments of an engine-driven work machine300, such as an engine351and a work machine main body (a generator main body in the example shown in theFIGS.352, and a sound proof case330that covers the base320in a state where the constituent equipment is arranged thereon.

The space inside this sound proof case330is separated into two chambers back and forth in the longitudinal direction of a sound proof box310by a partition wall312vertically erected on a base320, and one chamber of those is made to be an engine chamber330athat houses an engine351and a work machine main body (a generator main body)352, and the other chamber is made to be an air discharging chamber330bthat communicates with the outside of the machine through an air discharging port335provided on a top panel334.

Further, it is configured to communicate an engine chamber330aand an air discharging chamber330bwith each other by a communication port (not shown) provided in the central part of the aforementioned partition wall312, and to dispose a radiator of an engine351in a manner of facing this communication port and, in the case where the engine351is equipped with a supercharger, a heat exchanger354such as an intercooler or the like of the supercharger to provide a cooling fan355for introducing cooling air into this heat exchanger354to generate cooling air going from the engine chamber330ato the air discharging chamber330bby this cooling fan355and to introduce the cooling air after it exchanges heat with the heat exchanger354into the air discharging chamber330b, and to allow the cooling air introduced into the air discharging chamber330bto be discharged outside the machine through the air discharging port335provided on the top panel334.

As mentioned above when a cooling fan355is rotated to generate a flow of cooling air which goes from the engine chamber330ato the air discharging chamber330b, pressure becomes negative inside the engine chamber330a, and therefore, outside air is introduced from outside the machine into the engine chamber330aas cooling air.

Such introduction of cooling air from outside the machine is generally performed through an air intake port327provided on the lateral wall of a sound proof case330as shown inFIGS.7and8.

In this case, if an air intake port327is merely provided on the lateral wall of a sound proof case330, noise generated by an engine351, a work machine main body352or the like directly leaks out of the machine through the air intake port327.

In addition, when an engine-driven work machine300is used outdoors in the rain in the case where outside air is introduced into an engine chamber330athrough an air intake port327provided on the lateral wall of a sound proof case330in this manner, there is a risk that rainwater may enter the engine chamber330atogether with outside air through the air intake port327and wet the constituent equipment.

Particularly, a configuration in which an oil reservoir is provided in the base320of a sound proof box310so as to function as an oil weir in order to prevent the fuel, lubricating oil and so forth leaked out of equipment such as an engine351, a work machine main body352and a fuel tank (not shown) from leaking outside the machine causes the disposal costs for disposing of accumulated rainwater to accrue since, once the rainwater that has entered through an air intake port327accumulates in the oil reservoir provided in the base320, then the accumulated rainwater is polluted through being mixed with the leaked oil in the oil reservoir to preclude itself from being subjected to waste water disposal as it is.

In addition, if rainwater accumulates in an oil reservoir, there is even a risk that since no capacity remains in the oil reservoir to receive leaked oil when a leak of fuel or lubricating oil occurs, the leaked oil may overflow from the oil reservoir and pollute the surrounding environment thereof.

Therefore, in the case of providing an air intake port on the lateral wall of the sound proof case330, it is necessary to provide a duct360inside the air intake port327as shown inFIG.8(b)to prevent noise from leaking to the outside of the machine and take measures for preventing rainwater from entering the engine chamber330athrough the air intake port327.

Thus, in a configuration in which an air intake port327is provided on the lateral wall of a sound proof case330, it is necessary to provide a duct360inside the air intake port327, and therefore, in the case where it is not possible to secure a space for providing a duct360inside the air intake port327due to restrictions on the external shape or internal space of a sound proof box310, the configuration in which an air intake port327is provided on the lateral wall of the sound proof case330cannot be adopted.

For this reason, instead of a sound proof box for an engine-driven work machine which is configured to be provided with an air intake port on the lateral wall of a sound proof case, one that has a cooling air introduction flow path formed on the base has been also proposed.

As the base of such a sound proof box, the base470shown inFIG.9is disclosed in Japanese Patent KOKAI No. 2012-219704. (LOPI; automatically published after around 18 months from filing date regardless prosecution)

This base470is composed of a bed480on which to arrange an engine and a work machine main body, and a wheeled oil guard490on which to arrange the bed480, and in the oil guard490, ducts494and494are formed between the longitudinal outer walls491and491of the oil guard490and the lateral walls493and493of the oil reservoir492which are provided in parallel with the outer walls491and491, and the ducts494and494are made to communicate with the outside of the machine through an air intake port495provided in the outer walls491and491of the oil guard490.

Although these ducts494,494are separated by the partition plates496each of which is provided in front of and behind the position at which to dispose each wheel, these partition plates496are formed lower than the outer wall491of an oil guard490and the lateral wall493of an oil reservoir492and thereby the ducts494,494communicate with of a space497of a wheel upper portion.

Further, the aforementioned bed480which is arranged on an oil guard490has sack-shaped flow paths481,481surrounded by a wall surface on the top, bottom, front, back, left and right sides, formed in the part where it is placed on the aforementioned duct494, and through an opening482formed in the bottom wall of the sack-shaped flow paths481, the sack-shaped flow paths481communicate with a duct494directly or through the space497of the wheel upper portion, and the sack-shaped flow path481communicates with the space inside a sound proof case through the opening483provided on the lateral wall of the sack-shaped flow path481.

This is why a cooling air introduction flow path which goes from the air intake port495through the duct494, the space497of the wheel upper portion, the opening482provided on a bed480, the sack-shaped flow path481and the opening483to the space inside the sound proof case (not shown in the drawings) has been formed in a base470.

In the cooling air introduction flow path described in the above mentioned '219704, a cooling air introduction flow path in a complex shape is formed from an air intake port495provided on the outer wall491of an oil guard490to an opening483provided in a bed480, and thereby noise generated in the sound proof box is prevented from leaking directly outside the machine through the air intake port495.

Additionally, even if rainwater passes through an air intake port495together with cooling air by going through a flow path in a bent shape and by the outside air flowing from the lower side toward the upper side through the inside of a base470to an opening483provided in a bed480, the rainwater will drop out of the cooling air before reaching the opening483so as to be removed, and thereby, rainwater is favorably prevented from entering a sound proof case.

However, in the base470of the sound proof box described in the '219704, a structure of forming a duct494in an oil guard490by separately providing a lateral wall493of an oil reservoir492besides a longitudinal outer wall491and separating the duct494by a partitioning plate496at a plurality of locations is adopted, and a complicated structure such as one wherein to form a sack-shaped flow path481at a position above the duct494is adopted on the side of a bed480, in order to form the aforementioned inlet flow path in a complicated shape.

Therefore, since the configuration described in the '219704 is complicated in structure and requires many workloads that many components need to be attached by welding work or the like in order to form a flow path for introducing cooling air, it is high in manufacturing costs.

In addition, after a sound proof box is assembled, a duct494and the space497of the wheel upper portion are covered by the bottom plate of a bed480, and the bed480is also provided with a sack-shaped flow path481, and therefore, it is difficult to access the inside of a cooling air introduction flow path from the outside.

Therefore, dust sucked together with cooling air accumulates in a duct494or a sack-shaped flow path481, and in the case where a foreign matter such as sucked litter is clogged in the duct494or the sack-shaped flow path481, these are extremely difficult to remove, and the maintainability is poor.

Then, the present invention has been made in order to resolve a defect in the above-mentioned conventional art and the first object of the present invention is to provide a sound proof box for an engine-driven work machine which is relatively simple in structure and is equipped with a cooling air introduction flow path capable of introducing a sufficient volume of cooling air into the base without compromising the sound insulation and waterproofness of the sound proof box.

Additionally, the second object of the present invention is to provide a sound proof box for an engine-driven work machine in which a cooling air introduction flow path configured as described above can be provided in a base equipped with an oil reservoir to have the function of an oil weir without compromising the function of the oil reservoir.

Furthermore, the third object of the present invention is to provide a sound proof box for an engine-driven work machine which is so excellent in maintainability that even in the case where dust or the like accumulates in or a foreign matter is sucked into a cooling air introduction flow path, it can be easily subjected to removal or the like.

SUMMARY OF THE INVENTION

Means for solving the problems are described below with reference numerals used in the detailed description of the preferred embodiments. These reference numerals are intended to clarify the correspondence between the descriptions in the claims and the descriptions in the detailed description of the preferred embodiments, and it is needless to say that these reference numerals should not be used to restrictively interpret the technical scope of the present invention.

In order to achieve the First object, a sound proof box10for an engine-driven work machine1of the present invention comprises a base20arranging an engine51and a work machine main body52driven by the engine51and whose upper portion is opened, and a sound proof case30for covering the upper side of the base20, and a space in the sound proof case30being separated into two chambers by a vertically erected partition wall12to make one chamber as an engine chamber30ahousing the engine51and the work machine main body52and make the other chamber as an air discharging chamber30bintroducing the cooling air from the engine chamber30athrough a communication port13provided on the partition wall12and discharging to outside of the machine through an air discharging port35,

an upper opening of the base20being covered with a component arranging plate14at a position at which to place the air discharging chamber30b, to form a bottom surface of the air discharging chamber30bby the component arranging plate14,

an inside of the base20being separated into an upper stage and a lower stage by a floor plate22at a predetermined position in the height direction to make the upper stage side of the base20which includes the floor plate22as an upper stage portion20aand make the part lower than the floor plate22of the base20as a lower stage portion20b,

a separation wall24to divide a space23in the upper stage portion20ain the longitudinal direction being provided at a position below the engine chamber30ato make the space23in the upper stage portion20awhich is a space closer to the air discharging chamber30bthan the separation wall24as one space,

a cooling air introduction port15which communicates the engine chamber30awith the one space being provided between the partition wall12and the separation wall24,

a through hole25which communicates the one space23awith a space in the lower stage portion20bbeing provided at a bottom portion of the one space23aat a position below the air discharging chamber30b, and

a cooling air intake port27which communicates the space in the lower stage portion20bwith the outside of the machine being provided on lateral walls (211b,212b) of the lower stage portion20b(seeFIGS.1to6).

It is preferable that the cooling air intake port27is provided in the lateral walls (211b,212b,213b,214b) of the lower stage portion20bwhich is any part located below the engine chamber30a.

Each of the upper stage portion20aand the lower stage portion20bmay be formed as a discrete member, and that the base20is formed by arranging the upper stage portion20aon the lower stage portion20b.

The air intake port which is also used as a fork insertion port of a forklift may be provided on the lateral walls of the lower stage portion20bwhich are the longitudinal lateral walls (211b,212b) thereof.

Furthermore, the introduction port15may be covered with a mesh-like cover16(seeFIGS.1and2).

Moreover, in order to achieve the Second object, a sound proof box10for an engine-driven work machine1of the present invention is characterized in that a space in the upper stage portion20adivided by the separation wall24which is the other space23btherein is formed as a liquid-tight chamber to make an oil reservoir for reserving leaked oil.

Furthermore, in order to achieve the Third object, a sound proof box10for an engine-driven work machine1is characterized in that an inspection port28is further provided in the part of the lateral walls211,212,213,214of the base20wherein the one space23ais formed (one widthwise lateral wall213aat the air discharging chamber30bin the example in the drawings), and that a cover29for covering the inspection port28is provided (seeFIG.2).

Effect of the Invention

The configuration of the present invention which is described above has allowed the following remarkable effects to be obtained with the sound proof box10of the engine-driven work machine1of the present invention.

The inside of the base20of a sound proof box10is separated into an upper stage portion20aand a lower stage portion20bby a floor plate22at a given position in the height direction, a separation wall24dividing a space23inside the upper stage portion in the longitudinal direction is provided to set the space23divided by the separation wall24which is a space disposed closer to an air discharging chamber30bthan the separation wall24as one space23a, a cooling air introduction port15communicating an engine chamber30awith the one space23ais provided between the partition wall12and the separation wall24, a through hole25communicating the one space23awith a space in the lower stage portion20bis provided at the bottom portion of the one space23apositioned below the air discharging chamber30b, a cooling air intake port27communicating a space in the lower stage portion20bwith the outside of the machine is provided on the lateral walls (211b,212b,214b) of the lower stage portion20b, and thereby, a cooling air introduction flow path going from the air intake port27to the introduction port15can be formed in the base20.

As a result, when a flow of cooling air from the engine chamber30atoward the exhaust air chamber30bis generated by the blower55provided in the sound proof box10to create a negative pressure in the engine chamber30a, the air outside the machine which is introduced through the air intake port27can be introduced into the engine chamber30athrough the internal space of the lower stage portion20b, the through hole25, one space23aof the upper stage portion20a, and the introduction port15provided on the component arranging plate14.

As shown inFIGS.3and6, this cooling air introduction flow path is formed in a manner of meandering inside a base20, and thereby, the noise generated inside a sound proof box10cannot leak directly outside the machine through an air intake port27, and therefore, a cooling air introduction flow path can be formed inside the base20without compromising the sound insulation of the sound proof box10.

Additionally, even if as shown inFIGS.3and6, the cooling air flowing through this cooling air introduction flow path forms a flow meandering upward from the lower side to the upper side inside the base20to make rainwater pass through the air intake port27by being carried by the cooling air, this rainwater drops out of the flow of the cooling air before reaching the introduction port15and falls down so as to be removed, to allow the entrance of rainwater into an engine chamber30ato be prevented.

In addition, a cooling air introduction flow path can be formed in a base20in this way, and thereby, a cooling air intake port327does not necessarily need to be provided on the lateral walls of a sound proof case330as in the conventional sound proof box310described with reference toFIGS.7and8, and additionally, even in the case of providing a cooling air intake port327on the lateral wall of the sound proof case330, the air intake port327is allowed to be reduced in size and in number, and therefore, it is not necessary any more to provide a duct360on the inner surface of the lateral wall of a sound proof case, or it is made to be possible to reduce the duct360in size and number, and thereby, it is made to be possible to reduce the sound proof case in size and thus to reduce a whole engine-driven work machine in size.

In the configuration wherein an upper stage portion20aand a lower stage portion20bof the base20are formed as separate members and wherein the base20is formed by arranging the upper stage portion20aon the lower stage portion20b, a cooling air introduction flow path can be formed more easily in a base20.

Additionally, in the configuration wherein the air intake port27which is shared with a fork insertion port of a forklift is provided on the lateral walls of the lower stage portion20bwhich are the longitudinal lateral walls (211b,212b), the air intake port27does not need to be formed separately from the fork insertion port, and thereby the workloads required for manufacturing can be reduced.

In the configuration wherein the introduction port15is covered with a mesh-like cover16, even in the case where a foreign matter such as litter is sucked in, the foreign matter can be collected by the mesh-like cover16before it enters an engine chamber30a, and therefore, the occurrence of a serious failure or the like caused by the sucked litter getting entangled in the fan of a blower55in the engine chamber30acan be prevented in advance.

In the configuration wherein the other space23bin the upper stage portion20adivided by the separation wall24is formed as a liquid-tight chamber and used as an oil reservoir for reserving leaked oil, an oil reservoir23bcan be easily provided in a base20, and without carrying out any processing such as drilling on the wall surface of the oil reservoir23bpart, that is, without compromising the liquid-tightness of the oil reservoir23b, a cooling air introduction flow path can be relatively easily formed in the base20.

Furthermore, in the configuration wherein an inspection port28is provided on the part of the lateral walls211,212,213,214of the base20in which the one space23ais formed (in the example shown, one lateral wall213present on the side toward an air discharging chamber30b), and wherein a cover29to cover the inspection port28is provided, a cooling air introduction flow path can be easily accessed by simply removing the cover29without removing a sound proof case30or removing a component arranging plate14, and even in the case or the like where dusts accumulate on or foreign matters such as litters are sucked into the cooling air introduction flow path, these can be easily removed to greatly improve maintainability.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The sound proof box for an engine-driven work machine of the present invention is described below with reference to the accompanying drawings.

The reference numeral1inFIGS.1and2indicates an engine-driven work machine equipped with the sound proof box10of the present invention.

This engine-driven work machine1is one packaged in the sound proof box10by housing the constituent equipment of the engine-driven work machine1, such as an engine51, a work machine main body (in the example shown in the figure, the main body of a compressor)52and a receiver tank53, and is thereby configured to be capable of preventing leakage of noise generated in the sound proof box10and facilitating the transportation and installation.

The aforementioned sound proof box10which houses the constituent equipment of the engine-driven work machine1is composed of a plan-view rectangular base20on which to arrange the aforementioned engine51, the work machine main body52, and other constituent equipment, and a sound proof case30that covers the base20in the state where the constituent equipment is arranged thereon.

A sound proof case30among them is a box-shaped case consisting of a front panel31, a rear panel32, a side panel33, and a top panel34, and by arranging the sound proof case30on the base20, a housing space to house the constituent equipment arranged on the base20is formed in the sound proof case30.

In the sound proof case30shown inFIGS.1and2, the rear panel32, a part of the side panel33on the front side of the drawing, and the top panel34are in the state of being removed, and in the state where these members are arranged, the entire case is formed in the shape of a rectangular box, as shown by the dashed lines inFIGS.1and2.

The space inside this sound proof case30is divided into two chambers back and forth in the longitudinal direction of a sound proof box10by a partition wall12vertically erected from the upper face of a base20in order to form an engine chamber30awhere the engine51, the work machine main body52and so forth are housed on the side toward a front panel31, and an air discharging chamber30bwhich communicates with the outside of the machine through an air discharging port35on the side toward a rear panel32.

The above-mentioned engine chamber30aand air discharging chamber30bcommunicates with each other through a communication port13(seeFIGS.3and5) provided in the central part of the partition wall12, and the air discharging chamber30bcommunicates with the outside of the machine through an air discharging port35provided in the top cover34as shown inFIGS.1and2.

The above-mentioned base20on which to arrange the engine51, the work machine main body52and other constituent equipment of the engine-driven work machine1is formed in a plan-view rectangular shape formed by being bounded on four sides by a pair of longitudinal lateral walls211,212and a pair of widthwise lateral walls213,214, and the space inside the base20which is formed by being enclosed by these lateral walls211-214is divided by a floor plate22into upper and lower two stages at a given position in the height direction.

As for the base20divided into upper and lower stages by the floor plate22, the present specification describes the upper stage side including the floor plate22as the upper stage portion20a, and the part below the floor plate22as the lower stage portion20b.

Therefore, as shown inFIGS.1and2, one longitudinal lateral wall211of a base20has its upper portion side forming one longitudinal lateral wall211aof an upper stage portion20a, and has its lower portion side forming one longitudinal lateral wall211bof a lower stage portion20b(seeFIG.2), the other longitudinal lateral wall212of the base20has its upper portion side forming the other longitudinal lateral wall212aof the upper stage portion20a, and has its lower portion side forming the other longitudinal lateral wall212bof the lower stage portion20b(seeFIG.1),

one widthwise lateral wall213of the base20has its upper portion side forming one widthwise lateral wall213aof the upper stage portion20a, and has its lower portion side forming one widthwise lateral wall213bof the lower stage portion20b(seeFIG.2), and

the other widthwise lateral wall214of the base20has its upper portion side forming the other widthwise lateral wall214aof the upper stage portion20a, and has its lower portion side forming the other widthwise lateral wall214bof the lower stage portion20b(seeFIG.1).

This embodiment is configured so that as shown inFIGS.3and5, the parts of the upper stage portion20aexcept for the widthwise lateral walls213a,214aand the lower stage portion20bof the frame type formed by combining four molding members are each formed as separate members, that the longitudinal end edge part of the floor plate22of the upper stage portion20ais arranged on the longitudinal lateral walls211band212bof the lower stage portion20b, and that the base20can be formed by fixing both of the members together by bolting, welding, or other methods.

As shown inFIGS.3and5, this embodiment is configured that the longitudinal lateral walls211a,212aof the upper stage portion20aand the longitudinal lateral walls211b,212bof the lower stage portion20bare each composed of different members, and that when the upper stage portion20ais arranged on the lower stage portion20b, one longitudinal lateral wall211aof the upper stage portion20aand one longitudinal lateral wall211bof the lower stage portion20bform one longitudinal lateral wall211of the base20, and the other longitudinal lateral wall212aof the upper stage portion20aand the other longitudinal lateral wall212bof the lower stage portion20bform the other longitudinal lateral wall212of the base20.

On the other hand, each of the widthwise lateral walls213and214of a base20is formed by one mold plate, and is configured so that the mold plate (a lateral wall213or214) is attached to the part of a lower stage portion20bin the state before the base20is assembled.

Further, a configuration in which when the part of an upper stage portion20except for widthwise lateral walls213aand214ais arranged on a lower stage portion20b, the lower parts of these mold plates (widthwise lateral walls213and214) form the widthwise lateral walls213band214bof the lower stage portion20band the upper parts thereof form widthwise lateral walls213aand214aof the upper stage portion20ahas been made.

However, the configurations of lateral walls211-214of a base20are not limited to the configurations shown inFIGS.3and5, and longitudinal lateral walls211and212as well as widthwise lateral walls213and214may also be formed of one mold plate, and furthermore, the widthwise lateral walls213and214may also be formed by combining the widthwise lateral walls213a,214aof the upper stage portion20aand the widthwise lateral walls213b,214bof the lower stage portion20bwhich are formed as separate members in the same way as the longitudinal lateral walls211and212.

As shown inFIGS.1-3and5, the space23formed in the upper stage portion20ais divided into two sections back and forth in the longitudinal direction by a separation wall24erected on a floor plate22at the position below an engine chamber30a, and one space23awhich is present on the side of an air discharging chamber30bwith respect to this separation wall24and is the upper portion of a part corresponding to the position at which to form the air discharging chamber30bis covered with a component arranging plate14, and this component arranging plate14is used as the bottom surface of the air discharging chamber30b.

Further, the aforementioned partition wall12which separates the inside of a sound proof case30into an engine chamber30aand an air discharging chamber30bis erected on the side of the end edge14aof the side of the engine chamber30aof that component arranging plate14.

Between the lower end of the partition plate12(the end edge14aon the side of the engine chamber30aof the component arranging plate14) and the upper end of the separation wall24, the upper portion of one space of an upper stage portion20ais opened by a cooling air introduction port15, and the engine chamber30aand one space23ain the upper stage portion20acommunicates with each other through this introduction port15.

In the embodiment shown inFIG.3, as shown inFIGS.4A to4C, a separation wall24is formed by one vertical piece of an L-shaped cross-sectional angle plate, and an introduction port15is formed in the other piece of the angle plate extending from the upper end of the separation wall24toward the lower end of a partition plate12(the end edge14aon the engine chamber30aside of a component arranging plate14), and thereby, the other piece of the angle plate is made to be a frame body17to which to attach the mesh-like cover16to be described later.

In the configuration described with reference toFIGS.3and4, the aforementioned frame body17is explained as being integrally formed with a separation wall24and provided so as to protrude from the upper end of the separation wall24toward the end edge14aon the engine chamber30aside of a component arranging plate14, however, although the illustration is omitted, the frame body17may be, on the contrary to this, integrally formed with the component arranging plate14and provided so as to protrude from the end edge14aon the engine chamber30aside of the component arranging plate14toward the upper end of the separation wall24.

Additionally, the aforementioned frame body17does not necessarily need to be provided, and as shown inFIG.5, the part between the lower end of the partition plate12(the end edge14aon the side of the engine chamber30aof the component arranging plate14) and the upper end of the separation wall24may be left open without any attachment so that the entire of this part is used as the aforementioned introduction port15.

It is preferable to attach a mesh cover16to this introduction port15as shown inFIG.1andFIG.2so that even in the case where a foreign matter such as litter is sucked in through a cooling air introduction flow path, it cannot reach an engine chamber30a.

In the part of the aforementioned floor plate22provided in an upper stage portion20awhich forms the bottom surface of the one space23a, a through hole25penetrating through the floor plate22is formed, as shown inFIG.3, below the position at which to form an air discharging chamber30b, and one space23aof the upper stage portion20aand the space in a lower stage portion20bcommunicate with each other through that through hole25.

It is preferable that this through hole25is provided as far away as possible from an introduction port15as shown inFIGS.1to3, for example, at a position close to one widthwise lateral wall213aof an upper stage portion20a.

Although the embodiments shown inFIGS.1to3show a configuration of covering the entire bottom portion of an upper stage portion20awith the floor plate22, and forming the aforementioned through hole25through the floor plate22of the bottom surface part of one space23aof the upper stage portion20a, a configuration of making the entire bottom portion of one space23aas a through hole25without providing a floor plate22in the part where the one space23aof the upper stage portion20ais formed as shown inFIG.5may be adopted instead of that configuration.

The other space23bof the space23in the upper stage portion20aseparated by the separation wall24is formed liquid-tight to be used as an oil reservoir in this embodiment, and such a configuration that the constituent equipment of the engine-driven work machine1such as the engine51and the work machine main body52can be arranged on the arranging table26provided in the oil reservoir23bis made, and at the same time, fuel and lubricating oil leaked from the engine51and the work machine main body52are reserved in the oil reservoir23bto prevent them from leaking outside the machine.

InFIG.2, the reference numeral of28refers to an inspection port provided on one widthwise lateral wall213of the base20, and this inspection port28is blocked with a cover29when an engine-driven work machine1is in operation, and on the other hand, the cover29is removed at the time of inspection and thereby dusts accumulated in one space23aof an upper stage portion20a, foreign matters sucked into the portion, or the like can be removed through the inspection port28.

In the example shown in the figure, a configuration in which the inspection port28is provided on one widthwise lateral wall213of a base20is shown, however the inspection port28may also be provided on the part where one space23ais formed among the longitudinal lateral walls211and212of the base20.

Additionally, this inspection port28and the cover29are not essential components in the sound proof box10of the present invention and need not be necessarily provided.

In any part of the lateral wall of a lower stage portion20b, preferably the part of the lateral wall of the lower stage portion20bwhich is located below an engine chamber30a, a cooling air intake port27is formed.

In the illustrated embodiment, these air intake ports27are provided at six locations, that is, two locations on each of the longitudinal lateral walls211band212bof a lower stage portion20band two locations on the other widthwise lateral wall214b, however the positions at which to form the air intake ports27are not limited to the illustrated examples and these can be provided at any position on the lateral walls of the lower stage portion20b.

In the illustrated embodiment, the air intake ports27provided on the longitudinal lateral walls211band212bof a lower stage portion20bare formed in accordance with the width of the forks of a forklift so that the air intake ports27can be also used as fork insertion ports of a forklift.

By adopting such a configuration, in the case of obtaining, the base20of the sound proof box10of the present invention by modifying the structure of an already existing base equipped with the fork insertion port, no new air intake port27needs to be provided, so that the workloads required during the manufacturing can be reduced.

The sound proof box10configured as described above is configured so that on the side of the air discharging chamber30b, a heat exchanger54such as a radiator of an engine51is placed facing a communication port (not illustrated) provided on a partition wall12as shown inFIG.2while on the side of the engine chamber30a, a blower55having cooling fans (not illustrated) internally is placed through a communication port (not illustrated) toward the aforementioned heat exchanger54, that once cooling air is generated by operating the blower55, the air in the engine chamber30apasses through the heat exchanger54through a communication port13for heat exchange and is thereafter introduced into the air discharging chamber30b, and that the cooling air introduced into the air discharging chamber30bis discharged outside the machine through an air discharging port35.

In this way, when the air in the engine chamber30ais sent into the side of the air discharging chamber30bby the operation of the blower55, the inside of the engine chamber30atakes on negative pressure.

As a result, as shown by the arrows inFIG.3andFIG.6, the outside air introduced from the air intake ports27provided on the lateral walls211b,212b, and214bof the lower stage portion20bof a base20passes through the space inside the lower stage portion20bof the base20, reaches the inside of one space23aof the upper stage portion20athrough a through hole25, and is introduced into the engine chamber30athrough the cooling air introduction port15provided on the component arranging plate14.

In other words, a cooling air introduction flow path going from the air intake port27to the introduction port15is formed in the base20.

The cooling air introduction flow path formed in this base20can introduce cooling air in an amount necessary and sufficient for cooling a heat exchanger54, and as a result, unlike a conventional sound proof box310explained with reference toFIG.7andFIG.8, the sound proof box10of the present invention does not necessarily need to be provided with an air intake port327on the lateral wall of a sound proof case330, and even in the case of providing an air intake port327on the lateral wall of a sound proof case, the air intake ports327can be reduced in size and number, and therefore, it is not necessary any more to provide a duct360inside the position at which to form the air intake port327, or by allowing the ducts360provided inside the position at which to form the air intake port327to be reduced in size and number, the sound proof case is allowed to be reduced in size, and further the entire of an engine-driven work machine is allowed to be reduced in size.

In addition, the aforementioned cooling air introduction flow path formed in the base20precludes the noise generated in the sound proof case30from directly leaking outside the machine through an air intake port27, by being formed in a manner of meandering through the inside of the base20, and the sound insulation of the sound proof box10cannot be compromised by the formation of the cooling air introduction path.

Moreover, the cooling air flowing through this introduction path is configured to move from the lower side to the upper side while meandering, and thereby, even if rainwater passes through the air intake port27by being carried by the cooling air, the rainwater is separated from the cooling air before it reaches the introduction port15to fall downward to be removed, and thereby even to prevent rainwater from entering the engine chamber30a.

Furthermore, since the above configuration allows a cooling air introduction path to be formed without carrying out hole drilling process or the like on the upper stage portion20aof the base20which is the part where to form an oil reservoir23b, the other space (oil reservoir)23bwith liquid tightness can be easily obtained, for example, by separating the inside of the oil reservoir of an already existing base provided with a function of an oil weir by the separation wall24to form the other space (oil reservoir)23b.

Furthermore, since the configuration in which an inspection port28is provided on one widthwise lateral wall of the upper stage portion20aas described above allows the inside of a cooling air introduction flow path to be easily accessed by simply removing a cover29, excellence in maintainability is realized in a matter and so on that dust and a foreign matter can be easily removed, even in the case where problems such as dusts accumulating or foreign matters sucked in being clogged in the cooling air introduction flow path occur.

In the configuration shown inFIGS.1to6, the separation wall24which divides the space23in the upper stage portion20aof the base20is provided at a position relatively close to a partition wall12, and when an introduction port15is provided on the component arranging plate14between the lower end of the partition wall12and the upper end of the separation wall24, the introduction port15necessarily opens near the blower55.

In this configuration, the cooling air introduced into the engine chamber30acan be introduced into the heat exchanger54in a cold state before being warmed up in the engine chamber30a, thus improving the cooling performance of the engine51.

However, the configuration of the sound proof box10of the present invention is not limited thereto, and the aforementioned separation wall24may be provided by moving it toward the inner part of an engine chamber30ato a position farther than a partition wall12, for example, a position below the constituent equipment placed in the engine chamber30awhich is equipment that needs to be cooled.

By making such a configuration, it is made possible to open the introduction port15below the equipment that is considered to need to be cooled, and therefore, cooling air can be introduced into an engine chamber30abelow the constituent equipment that needs to be cooled, instead of introducing cooling air near a blower55, or together with introducing cooling air near the blower55, to allow this equipment to be cooled.

Thus the broadest claims that follow are not directed to a machine that is configure in a specific way. Instead, said broadest claims are intended to protect the heart or essence of this breakthrough invention. This invention is clearly new and useful. Moreover, it was not obvious to those of ordinary skill in the art at the time it was made, in view of the prior art when considered as a whole.

Moreover, in view of the revolutionary nature of this invention, it is clearly a pioneering invention. As such, the claims that follow are entitled to very broad interpretation so as to protect the heart of this invention, as a matter of law.

Now that the invention has been described;

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