Engine-driven generator

Abstract

To dispose a resistor, which is connected to a power generator body when raising the exhaust gas temperature of an engine, in a cooling air flow passage formed in a soundproof box, without deteriorating the heat balance performance.SOLUTION: A resistor 20, which is connected to a power generator body 70 when raising the exhaust gas temperature of an engine, is formed as an aggregate of a plurality of plate-like resistance elements 21 disposed parallel to each other at predetermined intervals, and the resistor 20 is disposed in a cooling air flow passage 14 so that a plane 21a of each resistance element 21 is parallel to the flow passage 14 for cooling air generated by a cooling fan 52. With this, a flow of cooling air is not obstructed by the resistor 20, and the resistor 20 can be disposed in the cooling air flow passage 14 and cooled while suppressing deterioration of the heat balance performance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an engine-driven generator that has an exhaust gas after-treatment device installed in the exhaust path of a diesel engine, which is the driving source of the generator body, and more specifically, to an engine-driven generator that is equipped with a resistor connected to the generator body in order to apply a load to the engine when increasing the temperature of the exhaust gas introduced into the exhaust gas after-treatment device. [Background technology]

[0002] In engine-driven generators, diesel engines are generally used as the engine that drives the generator itself. However, due to its structure, diesel engines produce more particulate matter (hereinafter referred to as "PM") and nitrogen oxides (hereinafter referred to as "NO") during combustion compared to gasoline engines. X ") is emitted along with the exhaust gas.

[0003] This PM and NO X As PM and NOx emitted by diesel engines are a cause of air pollution and health damage, exhaust gas regulations have been implemented. X Regulatory values ​​(mass per unit output [g / kWh]) are set.

[0004] In order to comply with these emission regulations, the exhaust tract of a diesel engine is equipped with an exhaust gas aftertreatment device consisting of an oxidation catalyst (Diesel Oxidation Catalyst: hereafter referred to as "DOC"), a diesel particulate filter (DPF) or a urea SCR (Selective Catalytic Reduction) device, or a combination of both. This reduces PM and NOx. X Efforts are being made to reduce emissions.

[0005] When the temperature of the DOC rises above its activation temperature due to the heat of the exhaust gas, NO 2 This NO2 is used as an oxidizer to burn and remove PM.

[0006] In addition, the DPF is placed on the secondary side of the aforementioned DOC, and captures PM remaining in the exhaust gas and removes it from the exhaust gas.

[0007] In addition, the urea SCR device sprays urea water into the exhaust gas after it has passed through the DOC, and converts ammonia (NH 3 ) is generated, and the exhaust gas after spraying the urea solution is introduced into the SCR catalyst, and the ammonia generated is converted into NO X It reduces nitrogen to harmless nitrogen (N 2 ) and water (H 2 O).

[0008] In addition, urea SCR devices are usually further equipped with a DOC downstream of the SCR catalyst that breaks down the ammonia remaining in the reduction reaction into nitrogen and water.

[0009] In this way, the exhaust gas aftertreatment device equipped with the above-mentioned DOC and / or urea SCR device together with this DOC is installed in the exhaust duct of the engine of the engine-driven generator, and PM and NO in the exhaust gas are removed. X However, even in an engine-driven generator equipped with such an exhaust gas aftertreatment device, if the engine is operated under low load conditions and the exhaust gas temperature is kept low, the following problems can occur:

[0010] When the engine is operated with the exhaust gas temperature below the DOC activation temperature, NO 2 Therefore, PM is not burned by the DOC and the amount of PM in the exhaust gas cannot be reduced.

[0011] Therefore, if this operating condition is maintained for a long period of time, in an exhaust gas aftertreatment device that has a DPF on the secondary side of the DOC, a further problem occurs in that the accumulation of PM in the DPF progresses, causing the DPF to become clogged.

[0012] In addition, in a configuration where a urea SCR device is installed on the secondary side of the DOC, if the exhaust gas temperature is below the activation temperature of the DOC, unburned organic matter such as PM that could not be burned by the DOC accumulates on the SCR catalyst, and the temperature of the exhaust gas introduced into the SCR catalyst does not increase, resulting in a decrease in NOx in the SCR catalyst. X The reduction of NO is not sufficient and ammonia-derived impurities adhere to the SCR catalyst. X The reduction performance of the catalyst decreases.

[0013] In particular, if the piping from the engine to the exhaust gas aftertreatment device is long, the temperature of the exhaust gas reaching the exhaust gas aftertreatment device will be lower, making such poor combustion of PM, accumulation of PM in the DPF, and reduced performance of the SCR catalyst more likely to occur.

[0014] Therefore, in an engine-driven generator having the aforementioned DOC or an exhaust gas aftertreatment device equipped with a DOC together with a DPF and / or a urea SCR device, when the exhaust gas temperature reaches a predetermined low temperature, when the engine is operated continuously at a low load for a predetermined period of time, when the amount of PM accumulated in the DPF exceeds a certain amount, and every predetermined accumulated operating time of the engine-driven generator, the exhaust gas temperature is raised to raise the temperature of the DOC in the exhaust gas aftertreatment device above the activation temperature, thereby promoting the combustion of unburned organic matter in the exhaust gas including PM, and / or the further increase in exhaust gas temperature accompanying the combustion of such unburned organic matter causes regeneration of the DPF (forced regeneration) which forcibly burns the PM accumulated in the DPF, and cleaning of the SCR catalyst (performance restoration).

[0015] In order to achieve this increase in exhaust gas temperature, an electrical load known as a "dummy load" is installed on the engine-driven generator, and this electrical load is connected to the generator body so that the generator body generates electricity according to the power consumption of the electrical load, thereby increasing the load on the engine (engine output) and raising the temperature of the exhaust gas.

[0016] In the configuration of such an engine-driven generator, the equipment already installed in the engine-driven generator is treated as the aforementioned electrical load. In Patent Document 1 listed below, an electric heater that heats the engine's cooling water is treated as the aforementioned electrical load, and this electric heater is connected to the generator body when regenerating the DPF (see Patent Document 1).

[0017] Also proposed is an engine-driven generator that is equipped as the aforementioned electrical load with a dedicated resistor used to increase the engine exhaust temperature. As such a resistor, an engine-driven generator 100 has been proposed that is equipped with a resistor 120 constructed by mounting multiple wire-wound resistance elements 121, each having a resistance wire 121b wound in a spiral shape around the outer periphery of a cylindrical core material 121a, in a row on a rectangular frame 122, as shown in Figure 5 (see Figures 2 and 3 of Patent Document 2).

[0018] In this way, when an electric heater or resistor is connected to the generator body, the electric heater or resistor 120 generates heat when electricity is applied.

[0019] Even if such heat is generated, in a configuration in which the electrical load is an electric heater that heats the engine coolant, such as the engine-driven generator described in Patent Document 1 cited above, the heat generated by the electric heater is exchanged with the engine coolant and dissipated in the radiator, so there is no need to take measures against the heat generation.

[0020] However, in a configuration such as that of Patent Document 2, which includes a dedicated resistor 120 used to increase the engine exhaust temperature, it is necessary to employ a configuration for cooling this resistor 120.

[0021] Therefore, in the above-mentioned Patent Document 2, as shown in Figure 6, a configuration is adopted in which the above-mentioned resistor 120 is placed at any position in the cooling air flow path 114 leading from the cooling fan 152 of the engine 150 to the exhaust port 113 provided in the top panel 112d of the soundproof box 110, so that the juxtaposition surface P of the resistance element 121 is perpendicular to the cooling air flow path 114 (see Figure 2 of Patent Document 2).

[0022] In addition, reference numeral 130 in FIG. 6 denotes an exhaust duct 130 that covers the upper part of the exhaust port 113 described above provided on the top plate of the soundproof box 110 of the engine-driven generator 100 . [Prior art documents] [Patent documents]

[0023] [Patent Document 1] JP 2016-104974 A [Patent Document 2] JP 2016-17486 A Summary of the Invention [Problem to be solved by the invention]

[0024] In the configuration of the engine-driven generator 100 of Patent Document 2 mentioned above, as described above, the juxtaposed surface P of the multiple resistance elements 121 is arranged perpendicular to the cooling air flow path 114, so that all of the resistance elements 121 can be cooled by applying cooling air to them approximately evenly.

[0025] However, when a resistor 120 having such a structure is provided, the cooling air flowing inside the soundproof box 110 encounters a large resistance when passing through the resistor 120, and the flow rate (exhaust air volume) of the cooling air passing through the cooling air flow path 114 and exhausted outside the machine through the exhaust port 113 decreases.

[0026] Therefore, if a resistor 120 having the above-mentioned structure is placed in the cooling air flow path 114, the cooling performance of the equipment housed in the soundproof box 110 will be deteriorated, and the heat balance performance of the engine-driven generator 100 will be reduced.

[0027] Therefore, the present invention has been made to eliminate the drawbacks of the above-mentioned conventional technology, and aims to provide an engine-driven generator equipped with an exhaust gas aftertreatment device, which is capable of suppressing a reduction in the amount of cooling air passing through the cooling air flow path, and therefore a deterioration in heat balance performance, while also being able to cool the resistor itself appropriately, even when a configuration is adopted in which a resistor connected to the generator main body to raise the engine's exhaust gas temperature when activating a DOC provided in the exhaust gas aftertreatment device, regenerating a DPF, cleaning an SCR catalyst, etc., is placed in the above-mentioned cooling air flow path. [Means for solving the problem]

[0028] The means for solving the problems are described below together with the reference numerals used in the description of the embodiment of the invention. The reference numerals are used to clarify the correspondence between the description of the claims and the description of the embodiment of the invention, and needless to say, are not used to restrict the interpretation of the technical scope of the present invention.

[0029] In order to achieve the above object, the engine-driven generator 1 of the present invention is In an engine-driven generator 1, the generator 1 includes an engine 50 which is a diesel engine, a generator body 70 driven by the engine 50, an exhaust gas aftertreatment device 82 provided in an exhaust passage of the engine 50, and a resistor 20 connected to the generator body 70 when increasing the temperature of the exhaust gas introduced into the exhaust gas aftertreatment device 82. The resistor 20 is formed as an assembly of a plurality of flat plate-like resistive elements 21 arranged in parallel at a predetermined interval, The plane 21a of each resistor element 21 faces the flow path 14 of the cooling air generated by the cooling fan 52. always parallel Vertical surface Achieve It also exerts a straightening effect on the cooling air that changes direction from horizontal to vertical. The resistor 20 is disposed in the flow path 14 of the cooling air as shown in FIG.

[0030] In the engine-driven generator 1 having the above configuration, The cooling fan 52 is arranged in the soundproof box 10 so that the blowing direction BD of the cooling fan 52 is horizontal, and an exhaust chamber 10b is provided in the soundproof box 10 to introduce the cooling air from the cooling fan 52 and communicate with the outside of the machine via an exhaust port 13 provided in the top plate (top panel 12d) of the soundproof box 10, forming a flow path 14 for the cooling air from the cooling fan 52 to the exhaust port 13, and The resistor 20 can be configured to be accommodated below the exhaust port 13 so that the plane 21a of each resistor element 21 forms a vertical plane parallel to the blowing direction BD of the cooling fan 52 (Claim 2: see Figures 1 and 2).

[0031] In addition, instead of the above configuration, The cooling fan 52 is arranged in the soundproof box 10 so that the blowing direction BD of the cooling fan 52 is horizontal, and an exhaust chamber 10b for introducing cooling air from the cooling fan 52 is provided in the soundproof box 10, and among the side walls of the soundproof box 10 that define the exhaust chamber 10b, within a range of a predetermined height from the upper end of the side wall (rear panel 12b) forward in the blowing direction BD of the cooling fan 52, an exhaust port 31 that opens upward is provided, and an exhaust duct 30 that extends the exhaust chamber 10b in the blowing direction BD of the cooling fan 52 is provided, forming a flow path 14 for the cooling air from the cooling fan 52 to the blowing port 31 of the exhaust duct 30, The resistor 20 may be accommodated in the exhaust duct 30 such that the plane 21a of each of the resistance elements 21 forms a vertical plane parallel to the blowing direction BD of the cooling fan 52 (Claim 3: see Figures 3 and 4). Effect of the Invention

[0032] With the configuration of the present invention described above, the engine-driven generator 1 of the present invention can provide the following significant effects.

[0033] The resistor 20 is formed as an assembly of a plurality of flat resistance elements 21 arranged in parallel planes at a predetermined interval, and the resistor 20 is arranged in the flow path 14 of the cooling air generated by the cooling fan 52 so that the plane 21a of each resistance element 21 is oriented parallel to the flow path 14 of the cooling air. This makes it possible to suppress a reduction in the flow rate of the cooling air passing through the flow path 14 of the cooling air without the flow of the cooling air being impeded by the resistor 20.

[0034] As a result, the resistor 20 can be disposed in the flow path 14 of the cooling air and cooled appropriately while suppressing deterioration of the heat balance performance of the engine-driven generator 1.

[0035] Moreover, by making each resistive element 21 constituting the resistor 20 flat, the surface area of ​​the resistive element 21 can be made large, and the cooling efficiency of the resistor 20 itself can also be improved.

[0036] In a configuration in which the aforementioned cooling air flow path 14 in which such a resistor 20 is disposed is formed from the cooling fan 52 through the exhaust chamber 10b to the exhaust port 13 provided in the top plate (top panel 12d) of the soundproof box 10, the cooling air flow path 14 changes its direction from horizontal to vertical in the exhaust chamber 10b as shown by the dashed arrow in Figure 1, causing turbulence and making it difficult for the cooling air to escape.

[0037] However, in a configuration in which the resistor 20 is accommodated below the exhaust port 13 so that the plane 21a of each resistance element 21 of the resistor 20 forms a vertical plane parallel to the blowing direction BD of the cooling fan 52, the resistor 20 functions as a straightening plate, so that the amount of cooling air (exhaust air volume) discharged outside the machine through the exhaust port 13 can be increased compared to a configuration in which the resistor 20 is not provided in the exhaust chamber 10b, thereby improving the heat balance performance of the engine-driven generator 1.

[0038] Furthermore, an exhaust duct 30 is provided within a predetermined height range from the upper end of the side wall (rear panel 12b) forward in the blowing direction BD of the cooling fan 52 among the side walls of the soundproof box 10 that defines the exhaust chamber 10b, and a resistor 20 is accommodated within this exhaust duct 30.In this configuration, even a large resistor 20 that cannot be accommodated within the exhaust chamber 10b can be installed while suppressing a reduction in the exhaust volume.

[0039] In particular, by adopting a configuration in which an exhaust duct 30 is provided in addition to a configuration in which an exhaust port 13 is provided on the top plate of the exhaust chamber 10b, it is possible to significantly increase the amount of cooling air (exhaust air volume) discharged outside the machine compared to a configuration in which such an exhaust duct 30 and resistor 20 are not provided.

[0040] Furthermore, by preparing the exhaust duct 30 with the resistor 20 attached in advance, it becomes easy to assemble the resistor 20 to the engine-driven generator 1, and for example, the exhaust duct 30 equipped with the resistor 20 can be easily retrofitted to the engine-driven generator 1 as an optional item, etc.

[0041] Furthermore, in the configuration of the present invention, as described above, the exhaust duct 30 is provided to extend the exhaust chamber 10b in the blowing direction BD of the cooling fan 52 (rear of the soundproof box 10), so that the overall height of the engine-driven generator 1 can be kept low compared to the case in which an exhaust duct 130 that protrudes upward is provided as in the conventional engine-driven generator 100 described with reference to Figure 6.

[0042] As a result, when the engine-driven generator 1 is loaded onto the bed of a truck or the like and transported, it is possible to prevent the exhaust duct 30 from being hit and damaged when traveling through places with height restrictions, such as tunnels or under bridges. [Brief description of the drawings]

[0043] [Figure 1] FIG. 2 is a side view of the engine-driven generator of the present invention. [Diagram 2] 1 is a perspective view of a main portion of an engine-driven generator according to the present invention; [Diagram 3]FIG. 11 is a side view showing a modified example of the engine-driven generator of the present invention. [Figure 4] FIG. 4 is a perspective view of a main portion showing a modified example of the engine-driven generator of the present invention. [Diagram 5] (A) is a front view and (B) is a side view of a conventional exhaust gas temperature increase resistor. [Figure 6] FIG. 1 is a side view of a main portion of a conventional engine-driven generator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] The engine-driven generator of the present invention will be described below with reference to the accompanying drawings.

[0045] The symbol 1 in Figure 1 indicates an engine-driven generator of the present invention, and this engine-driven generator 1 is configured as a packaged type engine-driven generator 1 in which the component equipment is housed within a soundproof box 10 composed of a base 11 and a soundproof case 12.

[0046] The aforementioned base 11 that constitutes the soundproof box 10 is used to mount the components of the engine-driven generator 1, and other components such as an engine (water-cooled diesel engine) 50 and the generator main body 70 driven by the engine 50 are mounted on this base 11.

[0047] The aforementioned soundproof case 12, which covers the base 11 on which the components of the engine-driven generator 1 are mounted, is box-shaped and composed of side walls consisting of a front panel 12a, a rear panel 12b, and a side panel 12c, and a top panel 12d that forms a top plate covering the upper part of the space enclosed by these side walls.By covering the base 11 with this soundproof case 12, the engine-driven generator 1 is packaged as described above.

[0048] The space within the soundproof box 10 is divided into two compartments, an engine compartment 10a and an exhaust compartment 10b, by a vertically erected partition wall 15. Of these, the engine compartment 10a houses the engine 50, a radiator 51 mounted on the engine 50, a cooling fan 52 that blows cooling air onto the radiator 51, and the generator main body 70 driven by the engine 50.

[0049] On the other hand, the other chamber separated by the partition wall 15, the exhaust chamber 10b, houses an exhaust gas aftertreatment device 82 installed in the engine's exhaust path, as well as a resistor 20 which is connected to the generator main body 70 when raising the temperature of the exhaust gas introduced into the exhaust gas aftertreatment device 82 for activating the DOC, regenerating the DPF, cleaning the SCR catalyst, etc., as mentioned above.

[0050] In the central part of the aforementioned partition wall 15 that divides the soundproof box 10 into two chambers, a communication opening 16 that connects the engine chamber 10a and the exhaust chamber 10b is formed (see Figure 2), and the aforementioned radiator 51 housed in the engine chamber 10a is positioned opposite this communication opening 16 (see Figure 1).

[0051] A cooling fan 52 of the engine 50 is provided in the engine compartment 10 a so that the blowing direction BD of the cooling fan 52 can blow cooling air horizontally toward the radiator 51 and the communication port 16 .

[0052] Due to the configuration within the soundproof box 10, when the cooling fan 52 rotates, air from outside the aircraft is introduced into the engine compartment 10a through the air intake 17 (see Figure 1) provided on the side wall of the soundproof box 10 at the position where the engine compartment 10a is formed, and the cooling fan 52 blows out the introduced air in the blowing direction BD as cooling air.

[0053] The cooling air from the cooling fan 52 exchanges heat with the cooling water in the radiator 51 as it passes through the radiator 51 located in front of the blowing direction BD, and then reaches the exhaust chamber 10b through the communication port 16 provided in the partition wall 15, where it changes direction to vertical and is discharged outside the soundproof box 10 through the exhaust port 13 provided in the top plate of the exhaust chamber 10b.

[0054] Therefore, within the soundproof box 10 of the engine-driven generator 1, a flow path 14 for the cooling air generated by the cooling fan 52 is formed, extending from the cooling fan 52 to the exhaust port 13, and the resistor 20 mentioned above is arranged in this cooling air flow path 14.

[0055] As shown in FIG. 2, this resistor 20 is formed as an assembly of a plurality of flat plate-like resistance elements 21 arranged in parallel planes at predetermined intervals.

[0056] The individual resistive elements 21 constituting the resistor 20 are not particularly limited in structure as long as they are formed in a flat plate shape, and various structures can be adopted.

[0057] The resistance element 21 can be formed, for example, using a high resistance material such as a known metallic heating element such as a Ni-Cr system, an Fe-Cr-Al system, or an Fe-Cr-Al-Co system, or a non-metallic heating element such as silicon carbide, and such metallic or non-metallic resistance material may be directly molded into a plate to form the resistance element 21.

[0058] Furthermore, the resistive element 21 may have a multi-layer structure in which metallic or non-metallic resistive material is supported by being laminated, sandwiched, or enclosed on an insulating heat sink or the like.

[0059] Furthermore, the resistance element 21 may have a structure formed by winding a resistance wire around the outer periphery of a plate-shaped insulator.

[0060] As shown in Figure 2, the required number of such plate-shaped resistance elements 21 are attached parallel to each other at a specified interval on a holding frame 22, etc., and by connecting each resistance element 21 to each other, the assembly of these resistance elements 21 forms a resistor 20 having the specified resistance value required to obtain the desired increase in exhaust temperature.

[0061] The resistor 20 thus configured is disposed within the flow path 14 of the cooling air so that the plane 21a of each of the resistive elements 21 is parallel to the flow path 14 of the cooling air.

[0062] In this way, by arranging the resistor 20 so that the plane 21a of each resistance element 21 is parallel to the cooling air flow path 14, the flow resistance applied to the cooling air flowing through the cooling air flow path 14 can be made as small as possible, and even though the resistor 20 is arranged in the cooling air flow path 14, it is possible to suppress a decrease in the heat balance performance of the engine-driven generator 1.

[0063] As shown in Figures 1 and 2, in a configuration example in which an exhaust port 13 communicating with the exhaust chamber 10b is provided in the top panel 12d of the soundproof box 10, the aforementioned resistor 20 is attached below the aforementioned exhaust port 13 so that the plane 21a of each resistance element 21 forms a vertical plane parallel to the blowing direction BD of the cooling fan 52, and in the illustrated example, a plane parallel to the longitudinal side wall (side panel 12c) of the soundproof box 10.

[0064] By configuring in this manner, even if a cooling air flow path 14 is formed so that the cooling air blown out horizontally by the cooling fan 52 turns vertically within the exhaust chamber 10b, as shown by the dashed arrow in Figure 1, the plane 21a of the resistance element 21 can always be oriented parallel to the flow of the cooling air.

[0065] Furthermore, it has been confirmed that the configuration shown in Figures 1 and 2 can increase the flow rate (exhaust air volume) of cooling air discharged outside the machine through the exhaust port 13, compared to a configuration in which a resistor 20 is not arranged in the exhaust chamber 10b.

[0066] Table 1 below shows the change in exhaust air volume (actual measured value) and the change in allowable operating temperature depending on whether or not a resistor 20 is placed in the exhaust chamber 10b in the example configuration of the engine-driven generator 1 shown in Figures 1 and 2.

[0067] Here, the "permissible operating temperature" refers to the upper limit of the ambient temperature at which the engine-driven generator 1 can be operated, and is calculated according to the following formula based on the actual measured values ​​of the "engine cooling water temperature" and "engine oil temperature" measured when resistor 20 is installed and when it is not installed. Allowable operating temperature = Allowable outside operating temperature (40°C) + Minimum allowable value

[0068] Here, the "minimum allowable value" is the smaller of either the value obtained by subtracting the "actual measured value of engine coolant temperature" from the "required specification value of engine coolant temperature" or the value obtained by subtracting the "actual measured value of engine oil temperature" from the "required specification value of engine oil temperature."

[0069] In addition, the "Effect" in Table 1 indicates the percentage of the exhaust air volume and the permissible operating temperature when resistor 20 is installed, when the exhaust air volume and the permissible operating temperature when resistor 20 is not installed are each set to 100%.

[0070] [Table 1]

[0071] In the configuration of the engine-driven generator 1 of the present invention in which the resistor 20 is provided in the exhaust chamber 10b as shown in Figs. 1 and 2, the current is 26.7 m per minute, compared to the case in which the resistor 20 is not provided. 3 It has been confirmed that an increase in exhaust air volume of up to 445 liters per second can be achieved.

[0072] This significant increase in exhaust air volume is believed to be the result of the structure of resistor 20, in which multiple flat resistance elements 21 are arranged parallel to each other at a specified distance from one another, functioning as a straightening plate to straighten the flow of cooling air.

[0073] In other words, because the resistor 20 functioned as a straightening plate, it is believed that the occurrence of turbulence was suppressed and the cooling air was discharged smoothly, even when the cooling air flow path 14 was formed so that the cooling air changed direction from horizontal to vertical within the exhaust chamber 10b as described above.

[0074] By increasing the exhaust air volume in this manner, the inside of the soundproof box 10 is cooled appropriately, and the allowable operating temperature of the engine-driven generator 1 is improved by 5.2°C (13%) compared to when the resistor 20 is not installed.

[0075] Furthermore, as mentioned above, by making the resistive element 21 flat, the surface area of ​​the resistive element 21 is increased, which allows the resistive element 21 itself to have good heat dissipation properties, and the resistor 20 itself can be cooled appropriately.

[0076] In this way, in the configuration of the engine-driven generator 1 of the present invention, the resistor 20 connected to the generator main body 70 when increasing the engine exhaust temperature is arranged in the cooling air flow path 14 (exhaust air chamber 10b), yet it is possible to suppress a decrease in the amount of cooling air (exhaust air volume) discharged outside the machine, and in particular, in the configuration of the embodiment shown in Figures 1 and 2, it is possible to increase the exhaust air volume, thereby maintaining or improving the heat balance performance of the engine-driven generator 1 while also being able to suitably cool the resistor 20 itself.

[0077] In the engine-driven generator 1 described above with reference to Figures 1 and 2, a configuration has been described in which the aforementioned resistor 20, which is connected to the generator main body 70 when increasing the engine exhaust temperature, is housed within the exhaust chamber 10b of the soundproof box 10.

[0078] In contrast, in the engine-driven generator 1 shown in Figures 3 and 4, of the side walls of the soundproof box 10 that define the exhaust chamber 10b, a range of a predetermined height is removed from the upper end of the rear panel 12b, which is the side wall that is forward in the blowing direction BD of the cooling fan 52, and an exhaust duct 30 having an upwardly opening air outlet 31 is attached to this portion to extend the exhaust chamber 10b to the rear of the soundproof box 10.

[0079] Therefore, in this configuration, the cooling air generated by the cooling fan 52 is not only discharged outside the machine through the exhaust port 13 provided on the top plate of the exhaust chamber 10b, but also through the outlet 31 of the exhaust duct 30, thereby expanding the cooling air flow path 14 as shown by the dashed arrow in Figure 3.

[0080] A resistor 20 having a structure similar to that described with reference to Figure 2 is accommodated within this exhaust duct 30 so that the plane 21a of each resistance element 21 of the resistor 20 is a vertical plane parallel to the blowing direction BD of the cooling fan 52, which in the illustrated configuration is a plane parallel to the side panel 12c of the soundproof box 10.By configuring in this manner, the plane 21a of the resistance element 21 of the resistor 20 is positioned so as to be parallel to the flow of cooling air flowing within the exhaust duct 30.

[0081] In this manner, in the engine-driven generator 1 described with reference to Figures 3 and 4, the resistor 20 is housed within the exhaust duct 30, and the flow path 14 of the cooling air is expanded by the amount of the exhaust duct 30.

[0082] Moreover, the resistor 20 exerts a straightening effect on the cooling air flowing through the exhaust duct 30, thereby enabling the cooling air passing through the exhaust duct 30 to be discharged smoothly.

[0083] As a result, even in the configuration of the engine-driven generator 1 shown in Figures 3 and 4, even though a resistor 20 is provided in the cooling air flow path 14, the exhaust air volume can be increased rather than decreased, and the heat balance performance of the engine-driven generator 1 can be maintained or improved.

[0084] Furthermore, by making the resistive element 21 of the resistor 20 flat, the resistor 20 itself can be cooled appropriately, similar to the engine-driven generator 1 described with reference to Figures 1 and 2.

[0085] Furthermore, in the engine-driven generator 1 shown in Figures 3 and 4, the resistor 20 is provided in the exhaust duct 30 attached to the soundproof box 10, so that even a large resistor 20 that cannot be contained in the exhaust chamber 10b can be installed in the engine-driven generator 1.

[0086] Furthermore, by configuring the resistor 20 to be housed within an exhaust duct 30 attached to the soundproof box 10, the resistor 20 can be easily attached to the engine-driven generator 1 by preparing the exhaust duct 30 with the resistor 20 attached in advance, and it can also be easily accommodated in cases where the resistor 20 is installed as an option.

[0087] Furthermore, by arranging the aforementioned exhaust duct 30 in a direction that extends rearward from the soundproof box 10, the overall height of the engine-driven generator 1 can be maintained as it is without increasing, even though the exhaust duct 30 is provided.

[0088] As a result, when the engine-driven generator 1 of this embodiment is mounted on the bed of a truck or the like and passes through places with height restrictions such as under bridges or tunnels, it is possible to prevent the exhaust duct 30 from being hit and damaged. [Explanation of symbols]

[0089] 1 Engine-driven generator 10 Soundproof box 10a Engine room 10b Ventilation room 11 Foundation 12 Soundproof case 12a Front Panel 12b Rear panel 12c Side Panel 12d Top Panel 13 Ventilation outlet 14 Cooling air flow path 15 Partition Wall 16 Communication port 17 Air Intake 20 resistor 21 Resistance element 21a plane 22 Retaining frame 30 Exhaust duct 31 Air outlet 50 Engine 51 Radiator 52 Cooling fan 70 Generator body 82 Exhaust gas aftertreatment device 100 Engine-driven generator 110 Soundproof Box 112d Top Panel 113 Exhaust port 114 Cooling air flow path 120 resistor 121 Resistance element 121a Core material 121b resistance wire 122 frames 130 Exhaust duct 150 Engine 151 Radiator 152 Cooling fan P juxtaposition plane

Claims

1. An engine-driven generator including a diesel engine, a generator body driven by the engine, an exhaust gas aftertreatment device provided in an exhaust passage of the engine, and a resistor connected to the generator body when increasing the temperature of exhaust gas introduced into the exhaust gas aftertreatment device, The resistor is formed as an assembly of a plurality of flat plate-shaped resistive elements arranged in parallel at a predetermined interval, An engine-driven generator characterized in that the resistors are arranged in the flow path of the cooling air so that the plane of each resistance element always forms a vertical plane parallel to the flow path of the cooling air generated by the cooling fan and exerts a rectifying effect on the cooling air which changes direction from horizontal to vertical.

2. The cooling fan is disposed in a soundproof box so that the blowing direction of the cooling fan is horizontal, and an exhaust chamber is provided in the soundproof box to introduce cooling air from the cooling fan and communicate with the outside of the machine via an exhaust port provided in the top plate of the soundproof box, forming a flow path of the cooling air from the cooling fan to the exhaust port, and 2. The engine-driven generator according to claim 1, wherein the resistors are accommodated below the exhaust port such that the planes of the resistor elements form a vertical plane parallel to the blowing direction of the cooling fan.

3. The cooling fan is disposed in a soundproof box so that the blowing direction of the cooling fan is horizontal, and an exhaust chamber for introducing cooling air from the cooling fan is provided in the soundproof box, and a side wall of the soundproof box defining the exhaust chamber has an air outlet opening upward within a range of a predetermined height from the upper end of the side wall forward in the blowing direction of the cooling fan, and an exhaust duct is provided to extend the exhaust chamber in the blowing direction of the cooling fan, forming a flow path for the cooling air from the cooling fan to the air outlet of the exhaust duct, 2. The engine-driven generator according to claim 1, wherein the resistors are accommodated in the exhaust duct such that a plane of each of the resistor elements forms a vertical plane parallel to the blowing direction of the cooling fan.

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