engine

Abstract

This technology is suitable for engines equipped with exhaust treatment systems. [Solution] An exemplary engine is an engine to which an exhaust treatment device is attached, comprising a support for the exhaust treatment device and a vibration-damping member disposed at a connecting portion of the support.

Description

Technical Field

[0001] The present invention relates to an engine.

Background Art

[0002] Conventionally, an engine with an exhaust gas treatment device has been known (see, for example, Patent Document 1). In Patent Document 1, the engine has a support that is fixed to the engine body while supporting the exhaust gas treatment device. The support has a first support fixing portion, a second support fixing portion, and a third support fixing portion. These three fixing portions are provided so as to be dispersed at locations on the engine body that are separated from each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the number of fixing locations of the support for supporting the exhaust gas treatment device increases, it becomes necessary to secure a corresponding amount of space for fixing to the engine body. When the number of fixing locations increases, problems such as the need for the engine to be enlarged may occur, and it is preferable that the number of fixing locations be as small as possible. On the other hand, if the number of fixing locations is reduced too much, there is a concern that problems related to the reliability of the engine, such as a decrease in the vibration resistance strength of the exhaust gas treatment device, may occur.

[0005] An object of the present invention is to provide a technology suitable for an engine to which an exhaust gas treatment device is attached.

Means for Solving the Problems

[0006] An exemplary engine of the present invention is an engine to which an exhaust treatment device is attached, comprising a support for the exhaust treatment device and a vibration-damping member disposed at a connecting portion of the support. [Effects of the Invention]

[0007] According to an exemplary version of the present invention, in an engine to which an exhaust treatment device is installed, it is possible to achieve both space savings in the space required to fix the exhaust treatment device and the assurance of reliability. [Brief explanation of the drawing]

[0008] [Figure 1] Perspective view showing the general configuration of the engine. [Figure 2] Other perspective views showing the general configuration of the engine. [Figure 3] Schematic perspective view showing the support structure of the exhaust gas treatment device. [Figure 4] Another schematic perspective view showing the support structure of the exhaust treatment device. [Figure 5] Schematic perspective view showing the configuration of the front support. [Figure 6] Figure 5 shows an exploded perspective view of the front support. [Figure 7] Schematic perspective view showing the configuration of the rear support. [Figure 8] Figure 7 shows an exploded perspective view of the rear support. [Figure 9] Plan view showing the schematic configuration of the engine in the modified example. [Modes for carrying out the invention]

[0009] Exemplary embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and descriptions will not be repeated unless they require further explanation.

[0010] <1. Engine Overview> Figures 1 and 2 are perspective views showing the schematic configuration of an engine 100 according to an embodiment of the present invention. Note that the viewing direction of the engine 100 differs between Figure 1 and Figure 2. The engine 100 of this embodiment is a diesel engine used, for example, in industrial or agricultural machinery. In detail, the engine 100 is a naturally aspirated, water-cooled, vertical 4-cylinder engine. Note that the present invention is applicable to engines other than naturally aspirated, water-cooled, vertical 4-cylinder engines. For example, the present invention is applicable to engines equipped with a supercharger. Furthermore, for example, the present invention is not limited to 4-cylinder engines, but is also applicable to engines with a number of cylinders other than 4, such as 3-cylinder engines.

[0011] Herein, the directions in this specification are defined as follows: The dashed line AX in Figures 1 and 2 indicates the axis of the crankshaft (not shown) of the engine 100, and the direction in which this axis AX extends (crankshaft direction) is defined as the front-rear direction. The engine 100 is equipped with a cooling fan CF on one end face in the front-rear direction and a flywheel FW on the other end face. The side with the cooling fan CF is defined as the front side, and the side with the flywheel FW is defined as the rear side. That is, Figure 1 is a view from the front at an angle. Figure 2 is a view from the rear at an angle. Furthermore, the direction of gravity perpendicular to the front-rear direction is defined as the up-down direction, with the upstream side of the direction of gravity being defined as "up" and the downstream side as "down". In addition, the lateral direction perpendicular to the front-rear and up-down directions is defined as the left-right direction. The side that is to the left when looking from the front to the rear is defined as "left", and the side that is to the right is defined as "right".

[0012] These directions are merely descriptive terms and are not intended to limit the actual positional relationships or directions. In the drawings, the front is indicated by "F", the rear by "B", the left by "L", the right by "R", the top by "U", and the bottom by "D".

[0013] As shown in Figures 1 and 2, the engine 100 comprises an engine body 1 and an exhaust treatment device 2. The engine 100 is an engine to which the exhaust treatment device 2 is attached.

[0014] [1-1. Engine Body] The engine body 1 includes an oil pan 11, a cylinder block 12, a cylinder head 13, and a head cover 14.

[0015] The oil pan 11 is provided at the lower end of the engine 100. The oil pan 11 is formed in a container shape with an open upper side. Lubricating oil supplied to each lubricating part of the engine 100 is stored inside the oil pan 11.

[0016] The cylinder block 12 is disposed above the oil pan 11. A crankshaft (not shown) extending in the front-rear direction is disposed at the lower part of the cylinder block 12. A plurality of cylinders (not shown) arranged at intervals in the front-rear direction are provided at the upper part of the cylinder block 12. Each cylinder extends in the vertical direction. In this embodiment, the engine 100 is an in-line four-cylinder engine, and the number of cylinders is four. A piston (both not shown) connected to the crankshaft via a connecting rod is accommodated in each cylinder. Inside the cylinder, the piston can move in the vertical direction. The crankshaft rotates about the axis AX as the piston reciprocates in each cylinder.

[0017] The cylinder head 13 is disposed above the cylinder block 12. A combustion chamber is formed corresponding to each cylinder by the cylinder head 13 and the cylinder block 12. An intake manifold 15 is disposed on the left side surface of the cylinder head 13. An exhaust manifold 16 is disposed on the right side surface of the cylinder head 13.

[0018] The head cover 14 is disposed above the cylinder head 13. Inside the head cover 14, a valve operating mechanism (not shown) including a push rod and a rocker arm for operating an intake valve and an exhaust valve (both not shown) is accommodated.

[0019] The intake manifold 15 supplies air, which has been supplied via the intake pipe 17, etc., to the combustion chamber provided for each cylinder. In each combustion chamber, the air supplied from the intake manifold 15 is compressed, and then fuel supplied from the common rail fuel injector 18 is injected. This causes combustion in the combustion chamber, which in turn causes the piston to reciprocate up and down. The power thus obtained is transmitted to various devices downstream of the power source via the crankshaft, etc.

[0020] The exhaust manifold 16 collects the exhaust gases generated in each combustion chamber. Of the exhaust gases collected in the exhaust manifold 16, a portion is recirculated to the intake system (intake manifold 15) via the EGR (Exhaust Gas Recirculation) piping 19, and the rest is released to the outside via the exhaust treatment device 2.

[0021] In addition, as described above, a cooling fan CF is rotatably mounted on the front of the engine body 1, and the cooling fan CF rotates when power is transmitted from the crankshaft. Furthermore, a flywheel FW is positioned on the rear of the engine body 1, attached to the rear end of the crankshaft. The flywheel FW rotates integrally with the crankshaft.

[0022] [1-2. Exhaust treatment equipment] The exhaust treatment device 2 is an after-treatment device that processes exhaust gas discharged from the fuel chamber. The exhaust treatment device 2 comprises a cylindrical casing 21 that extends in the front-rear direction (crankshaft direction).

[0023] An oxidation catalyst and a filter (neither shown) are arranged inside the casing 21. The oxidation catalyst and the filter are arranged in series in the direction of exhaust gas movement. The oxidation catalyst is positioned upstream of the filter in the direction of exhaust gas movement. In this embodiment, the direction of exhaust gas movement within the casing 21 is from rear to front. That is, within the casing 21, the oxidation catalyst and the filter are arranged in order from rear to front.

[0024] The oxidation catalyst and filter remove carbon monoxide, nitric oxide, and particulate matter (PM) from the exhaust gas. The oxidation catalyst is made of platinum or the like and oxidizes (burns) unburned fuel, carbon monoxide, and nitric oxide contained in the exhaust gas. The filter is configured, for example, as a fall-flow type filter and collects particulate matter contained in the exhaust gas that has been treated by the oxidation catalyst.

[0025] An inlet pipe 22 is provided at the rear end of the casing 21. More specifically, the inlet pipe 22 extends downward from the outer circumference of the rear end of the casing 21. An inlet flange 22a, used for connection to the exhaust manifold 16, is provided at the lower end of the inlet pipe 22. A portion of the exhaust gas discharged from the exhaust manifold 16 enters the casing 21 through the inlet pipe 22 and is purified by an oxidation catalyst and a filter.

[0026] The purified exhaust gas is discharged to the outside of the casing 21 through an exhaust gas outlet 23 located on the front end surface of the casing 21. A silencer and tailpipe (not shown) are connected to the front end of the casing 21. In other words, the exhaust gas that exits the casing 21 through the exhaust gas outlet 23 is discharged to the outside via the silencer and tailpipe.

[0027] <2. Support structure for exhaust treatment device> Next, the support structure of the exhaust treatment device 2 in the engine 100 configured as described above will be explained in detail.

[0028] [2-1. Overview] Figures 3 and 4 are schematic perspective views showing the support structure of the exhaust gas treatment device 2 according to an embodiment of the present invention. Note that the viewing direction of the exhaust gas treatment device 2 etc. is different in Figures 3 and 4. Figure 3 is a view from the front at an angle. Figure 4 is a view from the rear at an angle.

[0029] As shown in Figures 3 and 4, the engine 100 includes a support 3 for supporting the exhaust treatment device 2. The support 3 is fixed to the engine body 1 while supporting the exhaust treatment device 2. More specifically, multiple support 3 are arranged in the direction in which the casing 21 of the exhaust treatment device 2 extends. In this embodiment, as described above, the casing 21 extends in the front-rear direction (crankshaft direction). For this reason, multiple support 3 are arranged side by side in the front-rear direction (crankshaft direction). By arranging the support 3 in this way, the support strength of the exhaust treatment device 2 can be improved.

[0030] More specifically, the multiple support members 3 consist of two members: a support member 3a fixed to one end of the casing 21 in the longitudinal direction and a support member 3b fixed to the other end. The more support members 3 there are, the greater the support strength of the exhaust treatment device 2 can be improved, so the number of support members 3 arranged in the longitudinal direction may be three or more. However, by using two support members 3 as in this embodiment, the amount of fixing space that needs to be secured on the engine body 1 for attaching the support members 3 to the engine body 1 can be reduced.

[0031] Furthermore, the locations where the two supports 3a and 3b are placed do not necessarily have to be at both ends in the longitudinal direction of the casing 21. For example, one of the two supports 3a and 3b may be placed at one end in the longitudinal direction of the casing 21, and the other at the center in the longitudinal direction of the casing 21. However, the support strength of the exhaust treatment device 2 can be improved by configuring the two supports 3a and 3b as in this embodiment, where one is placed at one end in the longitudinal direction of the casing 21 and the other is placed at the other end in the longitudinal direction of the casing 21. Note that the longitudinal end of the casing 21 may include not only the longitudinal end face of the casing 21, but also the portion inside the end face.

[0032] Hereinafter, of the two supports 3a and 3b, the support 3a located on the front end side of the casing 21 will be referred to as the front support 3a, and the support 3b located on the rear end side of the casing 21 will be referred to as the rear support 3b.

[0033] As shown in Figures 1 and 2, the two support members 3a and 3b are fixed to the engine body 1 and the exhaust treatment device 2. More specifically, as shown in Figures 3 and 4, the two support members 3a and 3b are fixed to the metal cylinder head 13 and casing 21 using fasteners. Bolts 4 are used as fasteners, for example.

[0034] The front support 3a extends vertically. The lower end of the front support 3a is fixed to the front end surface of the cylinder head 13 using bolts 4. The upper part of the front support 3a extends diagonally upward to the right. For this reason, the upper end of the front support 3a is offset to the right relative to the lower end. The upper end of the front support 3a configured in this way is fixed to a casing projection 21a that protrudes radially from the outer circumferential surface of the front end side of the casing 21 using bolts 4. Here, "radial direction" refers to the radial direction with respect to the center line of the cylindrical casing 21. The casing projection 21a is also part of the casing 21.

[0035] The rear support 3b extends vertically. The lower end of the rear support 3b is fixed to the rear end face of the cylinder head 13 using bolts 4. The upper side of the rear support 3b extends diagonally upward to the right, similar to the front support 3a. For this reason, the upper end of the rear support 3b is offset to the right relative to the lower end. The upper end of the rear support 3b configured in this way is fixed to the rear end face of the casing 21 using bolts 4.

[0036] In this embodiment, the front support 3a and the rear support 3b not only have different fixing positions at their upper ends relative to the casing 21, but their fixing positions relative to the cylinder head 13 are also offset in the left-right direction when viewed from the front. However, this configuration is merely illustrative. For example, the fixing structures of the front support 3a and the rear support 3b to the casing 21 may be the same, so that the front support 3a and the rear support 3b are fixed to the cylinder head 13 at the same position in the left-right direction when viewed from the front. Also, in this embodiment, the shapes of the front support 3a and the rear support 3b are different, but in some cases, their shapes may be the same.

[0037] [2-2. Detailed Configuration] In this embodiment, the engine 100 is equipped with a vibration-damping member 5 (see Figures 6 and 8 described later) positioned at the connecting portion of the support body 3. By positioning the vibration-damping member 5 at the connecting portion of the support body 3, the vibration damping effect of the vibration-damping member 5 can be obtained at the connecting portion, thereby suppressing the vibration of the exhaust treatment device 2 caused by the engine 100's operation. As a result, it is possible to ensure the support strength of the exhaust treatment device 2 even if the number of support bodies 3 is reduced. In other words, in the engine 100 to which the exhaust treatment device 2 is attached, it is possible to achieve both space savings in the space required to fix the exhaust treatment device 2 and the assurance of reliability.

[0038] Furthermore, in this embodiment, as a preferred configuration, the connecting portion of the support 3 has at least one of a pair of connecting surfaces that face each other in a direction perpendicular to the crank axis direction (i.e., left-right direction) in a plan view. The vibration-damping member 5 is then positioned between the pair of connecting surfaces. Here, the pair of connecting surfaces are the surfaces that face each other when connecting the members. The pair of connecting surfaces may be in contact with each other, or they may be separated from each other due to the presence of a member between them or other reasons.

[0039] The exhaust treatment device 2, which is attached to the engine body 1, is subjected to vibration by the engine 100. The excitation force of the engine 100 has components in the longitudinal, lateral, and vertical directions, but the dominant vibration mode in the exhaust treatment device 2 differs depending on the mounting structure of the exhaust treatment device 2 on the engine 100. Specifically, the dominant vibration mode in the exhaust treatment device 2 is a bending mode in which the device bends starting from the inlet flange 22a, and in the mounting structure of the exhaust treatment device 2 in this embodiment, vibration in the direction perpendicular to the crankshaft (lateral direction) in a plan view is dominant. For this reason, by placing a vibration damping member 5 between a pair of connecting surfaces that face each other in a direction perpendicular to the crankshaft direction (i.e., the lateral direction) in a plan view, the dominant vibration mode of the exhaust treatment device 2 can be effectively dampened. In other words, the vibration damping effect of the exhaust treatment device 2 can be effectively obtained.

[0040] By the way, the configuration in which the support 3 has a connecting portion having only one of a pair of connecting surfaces means that the connecting portion is the part that connects to a member other than the support 3. The member other than the support 3 referred to here is a member that makes up the engine body 1, or a member that makes up the exhaust treatment device 2. More specifically, the member other than the support 3 is, for example, the cylinder head 13 or the casing 21.

[0041] The vibration damping member 5 may be positioned on the connecting surface of the support 3 for connecting to the cylinder head 13, or on the connecting surface for connecting to the casing 21. Even with such a configuration, the dominant vibration mode of the exhaust treatment device 2 can be effectively dampened, and the vibration of the exhaust treatment device 2 can be suppressed. However, the cylinder head 13 and the casing 21 tend to become hot. Therefore, as will be described in detail later, it is preferable to position the vibration damping member 5 at a distance from the cylinder head 13 and the casing 21 by placing it between the first stay 31 and the second stay 32.

[0042] In this embodiment, the connecting portion of the support 3 has a configuration having a pair of connecting surfaces that face each other in the left-right direction. In a configuration where the connecting portion of the support 3 has a pair of connecting surfaces, the connecting portion is the part where members connect to each other within the support 3, which is composed of multiple members. In other words, in this embodiment, the support 3 has a segmented structure, and the vibration-damping member 5 is positioned at the connecting portion created by the segmentation. This configuration will be described in detail below.

[0043] In this embodiment, the vibration-damping member 5 is made of rubber, but this is an example, and the vibration-damping member 5 may be made of other elastic materials other than rubber.

[0044] Figure 5 is a schematic perspective view showing the configuration of the front support 3a. Figure 6 is an exploded perspective view of the front support 3a shown in Figure 5. Figure 7 is a schematic perspective view showing the configuration of the rear support 3b. Figure 8 is an exploded perspective view of the rear support 3b shown in Figure 7. Note that the nut member 7 is omitted from the exploded perspective views shown in Figures 6 and 8.

[0045] As shown in Figures 5 to 8, the support 3 has a first stay 31 and a second stay 32. The first stay 31 is fixed to the engine body 1. In detail, the first stay 31 is fixed to the cylinder head 13 using bolts 4 (see Figures 3 and 4). The second stay 32 is fixed to the exhaust treatment device 2. In detail, the second stay 32 is fixed to the casing 21 using bolts 4 (see Figures 3 and 4).

[0046] Furthermore, the connecting portion 30 of the support 3 is the part that connects the first stay 31 and the second stay 32. The vibration-damping member 5, which is placed in the connecting portion 30, is positioned between the first stay 31 and the second stay 32. In this configuration, the vibration-damping member 5 can be positioned away from the cylinder head 13 and casing 21, which tend to get hot. This prevents the vibration-damping member 5 from becoming too hot. As a result, it is possible to construct the vibration-damping member 5 from a relatively inexpensive rubber material, avoiding the need for high heat resistance in the vibration-damping member 5.

[0047] Furthermore, the support 3 has a recess 33 in the connecting portion 30 for accommodating the vibration-damping member 5. More specifically, at least one of the first stay 31 and the second stay 32 has a recess 33 for accommodating the vibration-damping member 5. The provision of the recess 33 makes it easier to position the vibration-damping member 5 in the connecting portion 30, for example, improving ease of assembly. In addition, the provision of the recess 33 allows the connecting portion 30 in which the vibration-damping member 5 is placed to be made compact.

[0048] As described above, the engine 100 is equipped with multiple support members 3. The multiple support members 3 include two types of support members: a front support member 3a and a rear support member 3b. Each of these support members 3a and 3b has a segmented structure.

[0049] (2-2-1. Configuration of the front support) As shown in Figures 5 and 6, the front support 3a has a front first stay 31a and a front second stay 32a. The front first stay 31a and the front second stay 32a may be made of the same type of processed material, but in this embodiment they are made of different types of processed materials. The front first stay 31a is a casting, and the front second stay 32a is a sheet metal processed material. This configuration ensures support strength and reduces manufacturing costs.

[0050] The front first stay 31a extends in the vertical direction. Two first stay fixing holes 311 are provided at the lower part of the front first stay 31a, which penetrate in the front-to-back direction and through which bolts 4 are passed. The front first stay 31a is positioned in front of the cylinder head 13 and is fixed to the front surface of the rectangular cylinder head 13 with two bolts 4 inserted from front to rear into the first stay fixing holes 311 (see Figure 3). Screw holes (not shown) are provided in appropriate places on the front surface of the cylinder head 13 to allow tightening with bolts 4.

[0051] In this embodiment, the front first stay 31a is also fixed to the intake manifold 15 (see Figure 1) located on the left side of the cylinder head 13. For fixing to the intake manifold 15, an intake manifold fixing portion 312 (see Figures 3 and 4) is provided on the rear surface of the front first stay 31a, near the vertical center. The intake manifold fixing portion 312 is provided with a through hole (not shown) that penetrates vertically. A bolt 4 is passed through this through hole from above, and when the bolt 4 is tightened, the front first stay 31a is fixed not only to the cylinder head 13 but also to the intake manifold 15 (see Figure 1). The upper surface of the intake manifold 15 is provided with a screw hole (not shown) that allows tightening with a bolt 4.

[0052] As shown in Figure 6, the front first stay 31a has a front first stay connecting surface 313 on the right side of its upper end. The front first stay connecting surface 313 constitutes one of a pair of connecting surfaces of the front connecting portion 30a. In detail, the front first stay connecting surface 313 has a rectangular planar portion perpendicular to the left-right direction.

[0053] The front first stay connecting surface 313 is provided with a front recess 33a that is recessed to the left relative to the flat portion of the front first stay connecting surface 313. The front recess 33a is a specific example of the recess 33 that accommodates the vibration-damping member 5. The front recess 33a is rectangular in shape when viewed from the side (from the left and right direction). The bottom surface of the front recess 33a is provided with a screw hole 314 for the first stay that penetrates in the left and right direction. Two screw holes 314 for the first stay are provided, spaced apart vertically.

[0054] The front second stay 32a is composed of a front first flat plate portion 321, a front second flat plate portion 322, and a front curved portion 323. The front first flat plate portion 321 is a flat plate-shaped portion having a plane perpendicular to the left-right direction. The front second flat plate portion 322 is a flat plate-shaped portion having a plane perpendicular to the front-rear direction. The front curved portion 323 is a curved portion connecting the rear end of the front first flat plate portion 321 and the left end of the front second flat plate portion 322. The front second stay 32a is L-shaped in plan view.

[0055] The front first flat plate portion 321 has a front second stay connecting surface 321a on its left side. The front second stay connecting surface 321a constitutes the other of the pair of connecting surfaces that the front connecting portion 30a has. In detail, the front second stay connecting surface 321a has a rectangular (more specifically, parallelogram) planar portion perpendicular to the left-right direction. The front first flat plate portion 321 is provided with a second stay-side screw hole 324 that penetrates in the left-right direction. Two second stay-side screw holes 324 are provided, spaced apart vertically.

[0056] The front second flat plate portion 322 is provided with a second stay fixing hole 325 that penetrates in the front-to-back direction. Two second stay fixing holes 325 are provided, spaced apart vertically. The second stay fixing holes 325 are, in detail, screw holes. The front second stay 32a and the casing projection piece 21a (see Figure 3, etc.) provided on the casing 21 are superimposed so that the front second flat plate portion 322 is positioned behind the casing projection piece 21a. In this state, bolts 4 are inserted from the front into a through hole (not shown) that penetrates in the front-to-back direction provided on the casing projection piece 21a and into the second stay fixing hole 325 provided on the front second flat plate portion 322. This fixes the front second stay 32a to the casing projection piece 21a (see Figure 3).

[0057] The front first stay 31a and the front second stay 32a are connected with their front first stay connecting surface 313 and front second stay connecting surface 321a facing each other in the left-right direction, with the vibration-damping member 5 interposed between the two surfaces 313 and 321a. This connection is achieved by passing the left end of a screw member 6 that penetrates the vibration-damping member 5 in the left-right direction through the screw hole 314 on the first stay side and the right end through the screw hole 324 on the second stay side, and then fitting nut members 7 to both ends of the screw member 6 and tightening them (see Figure 5).

[0058] During the connection, the vibration-damping member 5, which is made of rectangular parallelepiped-shaped vibration-damping rubber, is housed in the front recess 33a. The front recess 33a is configured to be recessed in a direction perpendicular to the crankshaft axis (left-right direction) in a plan view. As a result, the front recess 33a can properly house the vibration-damping member 5, which is sandwiched from the left and right directions at the front connecting portion 30a. The vibration-damping member 5, sandwiched from the left and right directions by the front first stay 31a and the front second stay 32a, can effectively dampen the dominant vibration mode of the exhaust treatment device 2 (left-right vibration). For this reason, in this embodiment, it is possible to minimize the number of support members 3 that the engine 100 provides to support the exhaust treatment device 2.

[0059] Furthermore, the vibration-damping member 5 has a thickness in the left-right direction that is greater than the depth (length in the left-right direction) of the front recess 33a. Therefore, when simply placed in the front recess 33a, it protrudes to the right from the right end of the front recess 33a. In this state, when tightening is performed using the screw member 6 and the nut member 7, the vibration-damping member 5 is housed in the front recess 33a in an elastically compressed state. For this reason, the vibration-damping member 5 can properly exert its vibration-damping effect despite being housed in the front recess 33a.

[0060] In this embodiment, the recess 33 for housing the vibration-damping member 5 is provided only in the front first stay 31a of the front second stay 32a, but this is merely an example. The recess 33 for housing the vibration-damping member 5 may be provided in both the front first stay 31a and the front second stay 32a, or it may be provided only in the front second stay 32a. Furthermore, the recess 33 for housing the vibration-damping member 5 may not be provided at all.

[0061] (2-2-2. Configuration of the rear support) Although the rear support 3b differs in shape from the front support 3a, it has a generally similar configuration. For this reason, when describing the rear support 3b, any content that overlaps with that of the front support 3a will be omitted as appropriate.

[0062] As shown in Figures 7 and 8, the rear support 3b has a rear first stay 31b and a rear second stay 32b. The rear first stay 31b is a casting, and the rear second stay 32b is a sheet metal product.

[0063] The rear first stay 31b extends in the vertical direction. Three first stay fixing holes 315 are provided at the lower part of the rear first stay 31b, which penetrate in the front-to-back direction and through which bolts 4 are passed. The rear first stay 31b is positioned behind the cylinder head 13 and is fixed to the rear surface of the rectangular parallelepiped cylinder head 13 with three bolts 4 inserted from rear to front into the first stay fixing holes 315 (see Figure 4). Note that screw holes (not shown) are provided in appropriate places on the rear surface of the cylinder head 13 to allow tightening with bolts 4.

[0064] Unlike the front first stay 31a, the rear first stay 31b is not fixed to any component of the engine body 1 other than the cylinder head 13. However, the rear first stay 31b may be fixed to any component of the engine body 1 other than the cylinder head 13, either in addition to or separately from the cylinder head 13. Similarly, the front first stay 31a may be fixed only to the cylinder head 13, just like the rear first stay 31b.

[0065] As shown in Figure 8, the rear first stay 31b has a rear first stay connecting surface 316 on the right side of its upper end. The rear first stay connecting surface 316 constitutes one of a pair of connecting surfaces of the rear connecting portion 30b. In detail, the rear first stay connecting surface 316 has a rectangular planar portion perpendicular to the left-right direction.

[0066] The rear first stay connecting surface 316 is provided with a rear recess 33b that is recessed to the left relative to the flat portion of the rear first stay connecting surface 316. The rear recess 33b is a specific example of the recess 33 that accommodates the vibration-damping member 5. The rear recess 33b is rectangular in shape when viewed from the side (from the left and right direction). The bottom surface of the rear recess 33b is provided with a first stay side screw hole 317 that penetrates in the left and right direction. Two first stay side screw holes 317 are provided, spaced apart vertically.

[0067] The rear second stay 32b is composed of a rear first flat plate portion 326, a rear second flat plate portion 327, and a rear curved portion 328. The rear first flat plate portion 326 is a flat plate-shaped portion having a plane perpendicular to the left-right direction. The rear second flat plate portion 327 is a flat plate-shaped portion having a plane perpendicular to the front-rear direction. The rear curved portion 328 is a curved portion connecting the front end of the rear first flat plate portion 326 and the left end of the rear second flat plate portion 327. The rear second stay 32b is L-shaped in plan view.

[0068] The rear first flat plate portion 326 has a rear second stay connecting surface 326a on its left side. The rear second stay connecting surface 326a constitutes the other of the pair of connecting surfaces that the rear connecting portion 30b has. In detail, the rear second stay connecting surface 326a has a rectangular (more specifically, trapezoidal) planar portion perpendicular to the left-right direction. The rear first flat plate portion 326 is provided with a second stay-side screw hole 329 that penetrates in the left-right direction. Two second stay-side screw holes 328 are provided, spaced apart vertically.

[0069] The rear second flat plate portion 327 is provided with three second stay fixing holes 320 that penetrate in the front-rear direction. The rear second stay 32b is positioned behind the casing 21 such that the rear second flat plate portion 327 faces the rear end surface of the casing 21. In this state, bolts 4 are passed through the second stay fixing holes 320 from front to rear, and the rear second stay 32b is fixed to the casing 21 by tightening the bolts 4 (see Figure 4). Note that the rear end surface of the casing 21 is provided with screw holes (not shown) that allow tightening with bolts 4.

[0070] The rear first stay 31b and the rear second stay 32b are connected with their rear first stay connecting surface 316 and rear second stay connecting surface 326a facing each other in the left-right direction, and the vibration-damping member 5 is interposed between the two surfaces 316 and 326a. This connection is made using a screw member 6 and a nut member 7, similar to the case of the front support 3a (see Figure 7). During this connection, the vibration-damping member 5, which is made of rectangular parallelepiped-shaped vibration-damping rubber, is housed in the rear recess 33b in an elastically compressed state. The vibration-damping member 5, sandwiched from the left and right by the rear first stay 31b and rear second stay 32b, can effectively dampen the dominant vibration mode of the exhaust treatment device 2 (left-right vibration). For this reason, in this embodiment, it is possible to minimize the number of support structures 3 that the engine 100 provides to support the exhaust treatment device 2.

[0071] <3. Variant> The mounting structure of the exhaust treatment device 2 described above is merely illustrative, and the method of attaching the exhaust treatment device 2 to the engine body 1 may be changed as appropriate. For example, the position of the exhaust treatment device 2, which extends in the front-rear direction, on the engine body 1 may be changed as appropriate. Furthermore, although the exhaust treatment device 2 (casing 21) is configured to extend in the front-rear direction as described above, the exhaust treatment device 2 may also be configured to extend in another direction, for example, in the left-right direction. As mentioned above, the dominant vibration mode of the exhaust treatment device 2, which originates from the vibration of the engine 100, will differ depending on the mounting structure of the exhaust treatment device 2 on the engine 100. Taking this into consideration, it is preferable to change the configuration of the connecting portion of the support body that supports the exhaust treatment device 2 as appropriate.

[0072] Figure 9 is a plan view showing the schematic configuration of an engine 100A according to a modified example. As shown in Figure 9, in the modified engine 100A, the exhaust treatment device 2 (casing 21) is configured to extend in the left-right direction. The exhaust treatment device 2 is located at one end of the engine 100 in the front-rear direction. More specifically, the exhaust treatment device 2 is located at the rear end of the engine 100, but the exhaust treatment device 2 may also be located at the front end of the engine 100.

[0073] In this modified example, the exhaust treatment device 2 is positioned above the flywheel housing that accommodates the flywheel FW provided on the engine body 1. In this modified example, there are two support members 3 that support the exhaust treatment device 2. The number of support members 3 may be changed as appropriate. The two support members 3 are positioned side by side in the direction in which the casing 21 of the exhaust treatment device 2 extends (left-right direction). More specifically, in a preferred configuration, the two support members 3 are positioned at one end and the other end of the casing 21 in the left-right direction. In Figure 9, both support members 3 are positioned behind the casing 21, but alternatively, one may be positioned in front of the casing 21 and the other behind the casing 21. Alternatively, both support members 3 may be positioned in front of the casing 21.

[0074] Each support 3 has a first stay 31 fixed to the engine body 1 (specifically, the cylinder head 13) and a second stay 32 fixed to the exhaust treatment device 2 (specifically, the casing 21). The first stay 31 and the second stay 32 are connected by a connecting portion 30, which has a pair of connecting surfaces facing each other in the front-rear direction (crankshaft direction). The vibration damping member 5 is placed between the pair of connecting surfaces. In addition, similar to the above embodiment, the connecting portion 30 of the support 3 may consist of only one of the pair of connecting surfaces, with the other connecting surface being part of the engine body 1 or the exhaust treatment device 2. Furthermore, at least one of the pair of connecting surfaces may be provided with a recess that is recessed in the front-rear direction (crankshaft direction) to accommodate the vibration damping member 5.

[0075] As described above, the dominant vibration mode in the exhaust treatment device 2 is the bending mode that originates from the inlet flange. However, in the mounting structure of the exhaust treatment device 2 in this modified example, vibration in the pitch direction (or longitudinal direction) of the engine 100 becomes dominant. For this reason, by arranging the vibration damping member 5 between a pair of connecting surfaces facing each other in the longitudinal direction (i.e., the crankshaft direction), as in this modified example, the dominant vibration mode of the exhaust treatment device 2 can be effectively dampened by the vibration damping member 5. In other words, the vibration damping effect of the exhaust treatment device 2 can be effectively obtained.

[0076] <4. Things to keep in mind> Various technical features disclosed herein can be modified in various ways without departing from the spirit of the technical creation. Furthermore, the multiple embodiments, examples, and modifications shown herein may be combined as possible.

[0077] <5. Addendum> An exemplary engine of the present invention is an engine to which an exhaust treatment device is attached, and may have a configuration (first configuration) comprising a support for the exhaust treatment device and a vibration-damping member disposed at a connecting portion of the support.

[0078] In the engine of the first configuration described above, the connecting portion may have at least one of a pair of connecting surfaces that face each other in a direction perpendicular to the crankshaft direction in a plan view, and the vibration-damping member may be positioned between the pair of connecting surfaces (second configuration).

[0079] In the engine of the first configuration described above, the connecting portion may have at least one of a pair of connecting surfaces facing each other in the direction of the crankshaft axis, and the vibration-damping member may be positioned between the pair of connecting surfaces (third configuration).

[0080] In an engine having any of the first to third configurations described above, the support body has a first stay fixed to the engine body and a second stay fixed to the exhaust treatment device, the connecting portion is the portion connecting the first stay and the second stay, and the vibration-damping member may be arranged between the first stay and the second stay (fourth configuration).

[0081] In the engine according to any of the first to fourth configurations described above, the support may have a configuration (fifth configuration) in which a recess for housing the vibration-damping member in the connecting portion.

[0082] In the engine of the fourth configuration described above, at least one of the first stay and the second stay may have a recess for housing the vibration-damping member (sixth configuration).

[0083] In the engine of the fifth or sixth configuration described above, the vibration-damping member may be housed in the recess in an elastically compressed state (seventh configuration).

[0084] In the engine according to any of the fifth to seventh configurations described above, the recess may be configured to be recessed in a direction perpendicular to the crankshaft axis, or in the direction of the crankshaft axis (eighth configuration).

[0085] In an engine according to any of the first to eighth configurations described above, the support members may be arranged in a plurality in the direction in which the casing of the exhaust treatment device extends (the ninth configuration).

[0086] In the engine of the ninth configuration described above, the plurality of supports may consist of two supports: one fixed to one end of the exhaust treatment device in the longitudinal direction and the other fixed to the other end (the tenth configuration). [Explanation of Symbols]

[0087] 1. Engine body 2. Exhaust treatment system 3...Support 5. Vibration-damping components 30...Connection part 31...First Stage 32...Second Stage 33.. recessed 100, 100A... Engine 313...Front first stay connecting surface 316...Rear first stay connecting surface 321a Front second stay connecting surface 326a Rear second stay connecting surface

Claims

1. An engine to which an exhaust treatment device is installed, A support for the exhaust treatment apparatus, A vibration-damping member is disposed at the connecting portion of the support, An engine equipped with...

2. The connecting portion has at least one of a pair of connecting surfaces that face each other in a direction perpendicular to the crank axis in a plan view, The vibration-damping member is disposed between the pair of connecting surfaces, as described in claim 1.

3. The connecting portion has at least one of a pair of connecting surfaces that face each other in the direction of the crankshaft, The vibration-damping member is disposed between the pair of connecting surfaces, as described in claim 1.

4. The aforementioned support is A first stay fixed to the engine body, A second stay fixed to the exhaust treatment device, It has, The aforementioned connecting portion is the part that connects the first stay and the second stay. The engine according to claim 1, wherein the vibration-damping member is disposed between the first stay and the second stay.

5. The engine according to claim 1, wherein the support has a recess in the connecting portion for accommodating the vibration-damping member.

6. The engine according to claim 4, wherein at least one of the first stay and the second stay has a recess for housing the vibration-damping member.

7. The engine according to claim 5 or 6, wherein the vibration-damping member is housed in the recess in an elastically compressed state.

8. The engine according to claim 5 or 6, wherein the recess is recessed in a direction perpendicular to the crankshaft axis in a plan view, or in the direction of the crankshaft axis.

9. The engine according to any one of claims 1 to 6, wherein the support members are arranged in a plurality in the direction in which the casing of the exhaust treatment device extends.

10. The engine according to claim 9, wherein the plurality of supports consist of two supports: one fixed to one end of the exhaust treatment device in the longitudinal direction and the other fixed to the other end.

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