The present invention relates to engines, such as diesel engines mounted on work machines like construction machines or agricultural machines for example. Specifically, the present invention relates to an engine in which a diesel particulate filter (DPF) for purifying exhaust gas from an exhaust manifold is disposed above a cylinder head in an orientation orthogonal or approximately orthogonal to the rotational axis of a crankshaft in a plan view and an intake collector for returning part of the exhaust gas to an intake manifold as exhaust gas recirculation (EGR) gas is fixed to the intake manifold.
In the above-described engine, the DPF disposed above the cylinder head is in a lateral orientation orthogonal or approximately orthogonal to the rotational axis of the crankshaft in a plan view. Thus, space occupied around the engine can be decreased more than that, for example, in a case where the DPF is disposed along the direction of the rotational axis of the crankshaft.
To enable the DPF in the above-described lateral orientation to be supported on the engine, as described in Patent Literature 1 (hereinafter referred to as PTL1), a support mechanism for enabling the cylinder head and the intake manifold to support the DPF is typically provided. Such a support mechanism is made up of an inlet-side bracket for fixing a portion of the DPF positioned toward the exhaust manifold to a left side surface of the cylinder head, an outlet-side bracket for fixing a portion of the DPF positioned toward the intake manifold to a front surface of the cylinder head, and a coupling bracket for coupling an intermediate portion of the outlet-side bracket positioned between the top and bottom thereof to the intake manifold.
PTL1: Japanese Patent Application Laid-Open No. 2015-178813
In the above-described DPF supporting structure, the position in which the inlet-side bracket is attached to the left side surface of the cylinder head, the position in which the outlet-side bracket is attached to the front surface of the cylinder head, and the position in which the coupling bracket is attached to the intake manifold are close to each other with respect to a line segment in a direction orthogonal to the rotational axis of the crankshaft in a plan view. Thus, the vibration that has propagated to the engine can easily cause the DPF to vibrate in the pitch direction along the rotational axis direction of the crankshaft (the direction of arrows b in
Particularly in an engine mounted on a work machine, such as a skid steer loader or the like, an apparatus to be driven (hereinafter referred to as a driven apparatus), which is large in mass (see the portions indicated with the imaginary lines in
In view of such circumstances, the present invention is mainly aimed at providing an engine that can suppress damage on a DPF supporting mechanism due to vibration in the pitch direction through reasonable modification utilizing the disposition structure on the intake side of a cylinder head.
In a first distinctive aspect of the present invention, an engine includes: a cylinder head; a diesel particulate filter (DPF) that purifies exhaust gas from an exhaust manifold, the DPF being disposed above the cylinder head in an orientation orthogonal or approximately orthogonal to a rotational axis of a crankshaft in a plan view; an intake manifold; and an intake collector that returns part of the exhaust gas to the intake manifold as exhaust gas recirculation (EGR) gas, the intake collector being fixed to the intake manifold.
In the engine, a support mechanism that enables the cylinder head, the intake manifold, and the intake collector to support the DPF is provided. The support mechanism includes a first support position in which the cylinder head supports the DPF, a second support position in which the intake manifold supports the DPF, and a third support position in which the intake collector supports the DPF, and the third support position deviates from the first support position and the second support position in a direction of the rotational axis of the crankshaft.
In the above-described configuration, the intake collector of an EGR device is fixed to the intake manifold to reduce the emission amount of nitrogen oxide by returning part of exhaust gas as EGR gas to the intake manifold. Accordingly, the intake collector belongs to a vibration system identical to that to which the cylinder head and the intake manifold belong. In addition, the third support position of the support mechanism in which the intake collector supports the DPF deviates further in the direction of the rotational axis of the crankshaft than the first support position of the support mechanism in which the cylinder head supports the DPF and the second support position of the support mechanism in which the intake manifold supports the DPF.
Utilizing the disposition structure of the intake collector identical in vibration system to the cylinder head and intake manifold described above, the support mechanism that enables the cylinder head and the intake manifold to support the DPF further enables the intake collector to support the DPF. Thus, the DPF can be supported at three points deviating in the direction of the rotational axis of the crankshaft, which are the first support position, the second support position, and the third support position. Accordingly, supporting strength against vibration in the pitch direction along the direction of the rotational axis of the crankshaft can be enhanced. In addition, compared to a case in which the DPF supporting mechanism is fixed between members different in vibration system, occurrence of internal stress in the support mechanism can be further suppressed, and the support mechanism can be made have a sturdier structure.
Thus, through the above-described reasonable modification utilizing the intake collector in the disposition structure on the intake side of the cylinder head, damage on the support mechanism of the DPF due to vibration in the pitch direction can be suppressed.
In a second distinctive aspect of the present invention, the support mechanism is made up of a first support unit for enabling the cylinder head and the intake manifold to support the DPF, and a second support unit for enabling the intake collector to support the DPF.
With the above-described configuration, even in an already-existing engine in which only the first support unit for enabling the cylinder head and the intake manifold to support the DPF is provided, damage on the support mechanism of the DPF due to vibration in the pitch direction can be suppressed simply by adding the second support unit for enabling the intake collector to support the DPF. As a result, modification cost for the already-existing engine including the first support unit only can be reduced.
In addition, compared to a case in which the cylinder head or the intake manifold supports the second support unit, the rigidities of the cylinder head and the intake manifold can be secured more desirably through the sharing of the load with the intake collector.
In a third distinctive aspect of the present invention, the first support unit includes a first bracket for enabling the cylinder head and the intake manifold to support a portion of the DPF positioned toward the intake manifold, and the second support unit is constituted by a second bracket provided on and between the first bracket and the intake collector.
In the above-described configuration, the first bracket of the first support unit is provided among three parts, which are a portion of the DPF toward the intake manifold, the cylinder head, and the intake manifold. Thus, the distance between the positions in which the first bracket and the intake collector are provided is shorter than the distance between the DPF and the intake collector. In accordance with the decrease in the distance between the positions in which the first bracket and the intake collector are provided, the weight and cost of the second bracket that constitutes the second support unit can be reduced
In a fourth distinctive aspect of the present invention, the second support unit includes an abutting portion that is abuttable from above on an attachment portion provided on an upper surface of the intake collector, and the abutting portion is fastened to the attachment portion of the intake collector with a bolt oriented in an up-down direction.
In the above-described configuration, vibration in the pitch direction that acts on the DPF can be solidly received and supported by the abutting portion of the second support unit that abuts from the upper side, where the pitch direction occurs, on the attachment portion of the intake collector using bolts oriented in the up-down direction.
In a fifth distinctive aspect of the present invention, the DPF is disposed above the cylinder head and toward an end portion positioned away from an output shaft portion for a driven apparatus.
In the above-described configuration, as the DPF is positioned farther away from the output shaft portion for the driven apparatus, up-down vibration of the driven apparatus large in mass is amplified and acts as vibration in the pitch direction more largely. The amplified vibration in the pitch direction can be solidly received and supported at three points, which are the support positions among the cylinder head, the intake manifold, and the intake collector.
Embodiments of the present invention are described with reference to the drawings.
As illustrated in
In the present embodiment, the driven apparatus 100, which is large in mass, is fixed and coupled to the flywheel housing 9 as indicated with the imaginary lines in
An intake system of the diesel engine 1 includes an intake pipe 15, where a compressor 32 of the turbocharger 30 described later is provided, an intake collector 51 of an EGR device 50 described later, and the intake manifold 6.
As illustrated in
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The exhaust manifold 7 supplies the exhaust gas generated in the plurality of combustion chambers to the turbine 31 of the turbocharger 30 collectively. Part of the exhaust gas that has passed through the exhaust manifold 7 is returned by the EGR device 50 to the intake system as EGR gas and the remainder is purified through the DPF 40 and then discharged.
As illustrated in
The intake throttle member 52 allows the intake pipe 15 and the intake collector 51 to communicate. The recirculation exhaust gas pipe 54 as a returning pipeline is connected to the exhaust manifold 7 with interposition of an EGR cooler 53. The EGR valve member 55 allows the recirculation exhaust gas pipe 54 and the intake collector 51 to communicate. The amount of the EGR gas supplied to the intake collector 51 is adjusted by adjusting the degree of opening of an EGR valve (not illustrated) in the EGR valve member 55.
With the above-described configuration, fresh air (outside air) is supplied from the intake pipe 15 into the intake collector 51 through the intake throttle member 52 while EGR gas is supplied from the exhaust manifold 7 into the intake collector 51 through the EGR valve member 55. The fresh air from the intake pipe 15 and the EGR gas from the exhaust manifold 7 are mixed in the intake collector 51 and then the resultant mixture is supplied to the intake manifold 6. That is, part of the exhaust gas discharged from the diesel engine 1 to the exhaust manifold 7 is returned from the intake manifold 6 to the diesel engine 1 and accordingly, the maximum combustion temperature at the time of high-load operation is lowered and the amount of nitrogen oxide (NOx) emitted from the diesel engine 1 is reduced.
A gas inlet portion of the EGR cooler 53 is connected to an EGR gas extracting pipe 56 formed to be integral with the exhaust manifold 7. A gas outlet portion of the EGR cooler 53 is connected to the recirculation exhaust gas pipe 54 with interposition of a pipe joint member 57. The pipe joint member 57 is fastened to the exhaust manifold 7 with bolts.
The DPF 40 includes a cylindrical exhaust gas purification case 41 that extends in the left-right direction and is made of a material of refractory metal. The exhaust gas introducing portion 42 that includes an exhaust gas introducing inlet 42a (see
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In the present embodiment, as illustrated in
With the above-described configuration, the NO2 produced by the oxidation effect of the diesel oxidation catalyst 44 is supplied into the soot filter 46. The PMs contained in the exhaust gas of the diesel engine 1 are trapped at the soot filter 46 and continuously oxidized and removed by the NO2. In addition to the removal of the PMs in the exhaust gas of the diesel engine 1, the amounts of carbon monoxide (CO) and hydrocarbon (HC) contained in the exhaust gas of the diesel engine 1 are also reduced.
In the diesel engine 1 configured as described above, particularly in the diesel engine 1 mounted on a work machine, such as a skid steer loader or the like, the driven apparatus 100, such as a hydraulic pump or the like, which is large in mass and is used for the work machine directly coupled to the output shaft portion 2A of the crankshaft 2, is fixed and coupled to the flywheel housing 9 as indicated with the imaginary lines in
In view of the above, the support structure of the DPF 40 according to the present invention addresses such vibration in the pitch direction through reasonable modification utilizing the disposition structure on the intake side of the cylinder head 4. The following describes its specific structure in detail.
As illustrated in
Further, the first support unit 61 includes the first bracket 70 and a fixing band 90. The first bracket 70 is used to fix a portion of the exhaust gas purification case 41 positioned toward the intake manifold 6 to the cylinder head 4 and the intake manifold 6. The fixing band 90 is used to fix a portion of the exhaust gas purification case 41 positioned toward the exhaust manifold 7 to the cylinder head 4.
The second support unit 62 is constituted by a second bracket 80 provided on and between the first bracket 70 and the intake collector 51.
As illustrated in
The second attachment plate portion 72 is provided in a front end portion of the first attachment plate portion 71 and formed by being bent inward in the left-right direction at a right angle and extends obliquely downward toward a left side portion of the front surface 4a of the cylinder head 4. The third attachment plate portion 73 is provided in a lower end portion of the first attachment plate portion 71 and formed to be along the horizontal direction by being bent inward in the left-right direction at a right angle.
As illustrated in
In the present embodiment, the first bolt insertion holes 71a of the first attachment plate portion 71 are formed in portions corresponding to three locations in the circumferential direction of the split reinforcing flange plate 50A of the exhaust gas purification case 41. The first bolt 74 is inserted into the first bolt insertion hole 71a positioned centrally in the circumferential direction from the inside. The nut 75 corresponding to the central first bolt 74 is screwed from the outside. This insertion direction is opposite to the direction in which the other first bolts 74 are inserted into the first bolt insertion holes 71a on both sides in the circumferential direction. The bolt insertion hole 50b, which is approximately “U”-shaped and centrally positioned in the circumferential direction of the lower split reinforcing flange plate 50A, is engaged with and held on the first bolt 74 centrally positioned in the circumferential direction from above, in a state in which the exhaust gas purification case 41 of the DPF 40 is placed on an accepting surface 91a of a support base 91 of the fixing band 90. Thus, the load of the DPF 40 can be received and supported by the first bracket 70 and the support base 91 of the fixing band 90, and the fixing operation of the DPF 40 can be facilitated accordingly.
As illustrated in
In the present embodiment, the second bolt insertion holes 72a of the second attachment plate portion 72 are formed in three positions corresponding to the vertices of a triangle.
As illustrated in
In the present embodiment, the third bolt insertion holes 73a of the third attachment plate portion 73 are formed in two positions at predetermined spacing in the front-rear direction.
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With the above-described configuration, part of the load of the DPF 40 can also be supported in an abutting portion between the reinforcing plate 78 of the first bracket 70 and the load transmission plate 79. Thus, compared to a case in which the first attachment plate portion 71 of the first bracket 70 and the split reinforcing flange plate 50A positioned toward the exhaust gas purification case 41 are fastened only with the first bolts 74 and nuts 75, the support mechanism 60 of the DPF 40 can be made have a sturdier structure.
As illustrated in
The vertical plate portion 81 is formed to have an outline that is approximately “L”-shaped when viewed in the left-right direction. The horizontal plate portion 82 is formed at the lower end of the vertical plate portion 81 by being bent inward in the left-right direction at a right angle.
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In the present embodiment, the sixth bolt insertion holes 82a of the horizontal plate portion 82 and the second screw holes 66a of the second attachment portion 66 are each formed in two positions in the front-rear direction. The sixth bolt insertion holes 82a of the horizontal plate portion 82 are formed by being cut into the shape of approximate “U” in a plan view to be opened toward the intake manifold 6.
The horizontal plate portion 82 of the second bracket 80 and the second attachment portion 66 of the intake collector 51 are fastened by threading fifth bolts 84, which have been inserted into the sixth bolt insertion holes 82a of the horizontal plate portion 82 and are oriented in the up-down direction, into the second screw holes 66a of the second attachment portion 66 so that the fifth bolts 84 are screwed therein.
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In the support structure of the DPF 40 configured as described above, as illustrated in
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Further, as illustrated in
The split reinforcing flange plate 50A of the exhaust gas purification case 41 of the DPF 40 is firmly coupled to the first attachment plate portion 71 of the first bracket 70 with the plurality of first bolts 74 and nuts 75. In the coupled state, a portion of the DPF 40 positioned toward the intake manifold 6 is supported at three points deviating in the front-rear direction, which are the first support position P1 toward the front surface 4a of the cylinder head 4, the second support position P2 toward the first attachment portion 65 of the intake manifold 6, and the third support position P3 toward the second attachment portion 66 of the intake collector 51. Accordingly, supporting strength against vibration in the pitch direction along the rotational axis direction of the crankshaft 2 can be enhanced. In addition, compared to a case in which the support mechanism 60 of the DPF 40 is fixed between members different in vibration system, occurrence of internal stress in the support mechanism 60 can be suppressed more desirably, and the support mechanism 60 can be made have a sturdier structure.
Accordingly, through the above-described reasonable modification utilizing the intake collector 51 in the intake side disposition structure of the cylinder head 4, damage on the support mechanism 60 of the DPF 40 due to vibration in the pitch direction can be suppressed.
The first bracket 70 of the first support unit 61 is provided among three parts, which are a portion of the DPF 40 positioned toward the intake manifold 6, that is, the split reinforcing flange plate 50A of the exhaust gas purification case 41, the front surface 4a of the cylinder head 4, and the first attachment portion 65 of the intake manifold 6. Thus, the distance between the positions in which the first bracket 70 and the second attachment portion 66 of the intake collector 51 are provided is shorter than the distance between the DPF 40 and the intake collector 51. In accordance with the decrease in the distance between the positions in which the first bracket 70 and the second attachment portion 66 of the intake collector 51 are provided, the weight and cost of the second bracket 80 that constitutes the second support unit 62 can be reduced.
Further, compared to a case in which the cylinder head 4 or the intake manifold 6 supports the second bracket 80 of the second support unit 62, the rigidities of the cylinder head 4 and the intake manifold 6 can be secured more desirably through the sharing of load with the intake collector 51.
(1) Although the above-described embodiment discusses the diesel engine 1 in which the DPF 40 is disposed above the cylinder head 4 and toward an end portion positioned away from the output shaft portion 2A for the driven apparatus 100, the techniques of the present invention are also applicable to the diesel engine 1 in which the DPF 40 is disposed above the cylinder head 4 and toward an end portion positioned close to the output shaft portion 2A.
(2) Although the first bracket 70 of the first support unit 61 and the second bracket 80 of the second support unit 62 are structured as being separate in the above-described embodiment, the first bracket 70 and the second bracket 80 may be structured to be integral by bending, welding, or the like.
(3) Although the second bracket 80 of the second support unit 62 is provided between the first bracket 70 and the second attachment portion 66 of the intake collector 51 in the above-described embodiment, the second bracket 80 may be provided on and between the DPF 40 and the second attachment portion 66 of the intake collector 51.
The present invention is suitably applicable to various engines.
Number | Date | Country | Kind |
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2017-117372 | Jun 2017 | JP | national |
Number | Date | Country | |
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Parent | 17076824 | Oct 2020 | US |
Child | 17529174 | US | |
Parent | 16622218 | Dec 2019 | US |
Child | 17076824 | US |