Engine oil pan

Abstract

Provided is an engine oil pan that is less likely to emit engine noise.　An oil pan bottom wall 1a comprises: an upper convex medium-high wall 1aa extending in a front-back direction at a lateral center part of the oil pan bottom wall 1a; a pair of oil-introduction passage walls 1ab, 1ab extending in the front-back direction along both lateral sides of the medium-high wall 1aa; and a pair of oil-introduction passages 33 provided in the pair of oil-introduction passage walls 1ab, 1ab. The medium-high wall 1aa and the pair of oil-introduction passage walls 1ab, 1ab are formed from a part of an integral casting that forms an oil pan 1.

Description

engine oil pan

[0001] The present invention relates to an engine oil pan, and more particularly to an engine oil pan that is less likely to emit engine noise.

[0002] 2. Description of the Related Art Conventionally, there have been engine oil pans made of sheet metal (see, for example, Patent Document 1).

[0003] Japanese Utility Model Application Laid-Open Publication No. 4-121411

[0004] <<Problem>> Engine noise is easily released. The sheet metal oil pan of Patent Document 1 has low rigidity, and engine noise such as explosions is easily released via vibration of the oil pan.

[0005] An object of the present invention is to provide an oil pan for an engine that is less likely to emit engine noise.

[0006] The main features of the present invention are as follows: An oil pan for an engine, comprising: an oil pan that is rectangular in plan view and includes an oil pan bottom wall and an oil pan peripheral wall that is open at the top, wherein the axial direction of the crankshaft is the front-rear direction and the width direction of the engine, which is perpendicular to the front-rear direction, is the horizontal direction, and the rectangular oil pan has its long sides aligned along the front-rear direction and its short sides aligned along the horizontal direction, and the oil pan bottom wall includes an upwardly convex height wall that extends in the front-rear direction at a horizontal center of the oil pan bottom wall, a pair of oil introduction passage walls that extend in the front-rear direction along both lateral sides of the height wall, and a pair of oil introduction passages provided within the pair of oil introduction passage walls, and the height wall and the pair of oil introduction passage walls are formed as part of an integral casting that constitutes the oil pan.

[0007] The present invention has the following advantages: <Effect> Engine noise is less likely to be emitted. According to this invention, the mid-height wall and the pair of oil introduction passages are formed as part of the integral casting that makes up the oil pan, which increases the rigidity of the oil pan and makes it less likely to vibrate, reducing the emission of engine noise such as explosions.

[0008] 1A is a plan view of an engine oil pan according to an embodiment of the present invention, FIG. 1B is a cross-sectional view taken along line B-B of FIG. 1A, FIG. 1C is a cross-sectional view taken along line C-C of FIG. 1A, and FIG. 1D is a cross-sectional view taken along line D-D of FIG. 1A. 2A is an exploded perspective view of the oil pan, oil filter, and filter chamber top cover, and FIG. 2B is a schematic perspective view of the oil introduction path from the oil introduction passage through the oil filter chamber to the oil pump. 3A is a front view of the oil pan according to an embodiment of the present invention, FIG. 3B is a view taken along line B of FIG. 3A, FIG. 3C is a view taken along line C of FIG. 3A, FIG. 3D is a view taken along line D of FIG. 3B, and FIG. 3E is a view taken along line E of FIG. 3A.

[0009] 4A is a diagram illustrating an exhaust gas treatment case for an engine according to an embodiment of the present invention, with Fig. 4(A) being a perspective view of the exhaust gas treatment case with a support plate attached, viewed obliquely from above from the front, and Fig. 4(B) being a plan view of the support plate. Fig. 5A is a diagram illustrating the support structure of the exhaust gas treatment case of Fig. 4, with Fig. 5(A) being a cross-sectional view of the front support stay and its periphery, Fig. 5(B) being a cross-sectional view of line B-B in Fig. 5(A), Fig. 5(C) being a cross-sectional view of the rear support stay and its periphery, and Fig. 5(D) being a cross-sectional view of line D-D in Fig. 5(C). Fig. 6 is a perspective view of an engine according to an embodiment of the present invention, viewed obliquely from below from the front. Fig. 6 is a perspective view of the engine of Fig. 6, viewed obliquely from below from the rear.

[0010] 7 is a front view of the engine of Figure 6, a left side view of the engine of Figure 6, a right side view of the engine of Figure 6, a top view of the engine of Figure 6, a top view of the engine of Figure 6 with the support plate and exhaust gas treatment case removed, and a rear view of the engine of Figure 6.

[0011] 1 to 13 are diagrams illustrating an engine according to an embodiment of the present invention, and in this embodiment, a vertical in-line multi-cylinder diesel engine will be described.

[0012] As shown in Figure 9, this engine 12 includes a cylinder block 7, a cylinder head 17 attached to the top of the cylinder block 7, a cylinder head cover 14 attached to the top of the cylinder head 17, an engine cooling fan 16 located in front of the cylinder block 7, a flywheel housing 13 located at the rear of the cylinder block 7, and an oil pan 1 attached to the bottom of the cylinder block 7. The oil pan 1 is fastened to the cylinder block 7 with oil pan fastening bolts (not shown) inserted from below. As shown in Figures 7 and 13, a flywheel 13a is housed in the flywheel housing 13. An exhaust gas treatment case 15 is located above the cylinder head cover 14.

[0013] This engine includes an intake system, a fuel supply system, a combustion system, an exhaust system, and an exhaust gas treatment device. As shown in FIG. 10, the intake system includes an intake manifold (21) mounted on the right side of the cylinder head (17) and an intake throttle (21a) connected to the intake manifold (21). The fuel supply system includes a common rail (22) located on the right side of the cylinder head cover (14). The combustion system includes a plurality of cylinders (not shown) arranged in the front-rear direction within a cylinder section (7a) constituting the upper half of the cylinder block (7). The crankcase (7b) constituting the lower half of the cylinder block (7) houses the crankshaft (2) shown in FIG. 7. As shown in FIG. 9, the exhaust system includes an exhaust manifold (23) mounted on the left side of the cylinder head (17) and a turbocharger (24) mounted above the exhaust manifold (23). The exhaust gas treatment device includes an exhaust gas treatment case (15).

[0014] 6 and 7, the exhaust gas treatment case (15) of the exhaust gas treatment device includes a DPF housing case (15a) and an SCR housing case (15b) arranged on the right side of the DPF housing case (15a). The DPF housing case (15a) houses a DOC on the upstream exhaust side (rear side) and a DPF on the downstream exhaust side (front side). The SCR housing case (15b) houses an SCR catalyst on the upstream exhaust side (front side) and an ASC on the downstream exhaust side (rear side). The upstream exhaust side (rear side) of the DPF housing case (15a) is connected to the exhaust outlet of an exhaust turbine (24a) of a turbocharger (24) by a heat-resistant flexible pipe (15e). A mixing passage (15c) is interposed between the exhaust downstream side (front side) of the DPF housing case (15a) and the exhaust upstream side (front side) of the SCR housing case (15b), and a urea water injector (not shown) facing the mixing passage (15c) is attached to the DPF housing case (15a).

[0015] DPF is an abbreviation for diesel particulate filter, which captures PM in exhaust gas. PM is an abbreviation for particulate matter. DOC is an abbreviation for diesel oxidation catalyst, which oxidizes CO (carbon monoxide) and NO (nitrogen monoxide) in exhaust gas. SCR catalyst is an abbreviation for selective catalytic reduction type catalyst. ASC is an abbreviation for ammonia purification oxidation catalyst, which oxidizes NH ３ (Ammonia) to prevent slippage.

[0016] In this exhaust gas treatment device, exhaust gas passes through the DOC, DPF, SCR catalyst, and ASC in that order, and the DPF captures PM in the exhaust gas, and the DOC oxidizes NO (nitric oxide) in the exhaust gas to generate NO ２ (nitrogen dioxide) to continuously oxidize and burn PM accumulated in the DPF at a relatively low temperature, and urea water injected into the exhaust gas from the urea water injector causes ammonia to be adsorbed on the SCR catalyst, which then acts as a reducing agent to reduce NOx (nitrogen oxides) in the exhaust, resulting in N ２ (nitrogen gas) and H ２ O (water vapor) is obtained.

[0017] As shown in Figure 1(A), the oil pan 1 of this engine 12 is rectangular in plan view and includes an oil pan bottom wall 1a and an open-topped oil pan peripheral wall 1b. The axial direction of the crankshaft 2 shown in Figure 7 is the front-rear direction, and the width direction of the engine 12, which is perpendicular to the front-rear direction, is the horizontal direction. As shown in Figure 1(A), the rectangular oil pan 1 has its long sides aligned along the front-rear direction and its short sides aligned along the horizontal direction. As shown in Figures 1(A) to 1(C), the oil pan bottom wall 1a includes an upwardly convex center wall 1aa extending in the front-rear direction at the horizontal center of the oil pan bottom wall 1a, a pair of oil introduction passage walls 1ab extending in the front-rear direction along both lateral sides of the center wall 1aa, and a pair of oil introduction passages 3 provided within the pair of oil introduction passage walls 1ab. As shown in Figures 1(B) and 1(C), the center wall 1aa and the pair of oil introduction passage walls 1ab and 1ab are formed as part of an integral casting that constitutes the oil pan 1. Figures 3(A) to 3(E) show the external appearance of the oil pan 1.

[0018] In this engine 12, as shown in FIGS. 1(B) and 1(C), the mid-height wall 1aa and the pair of oil introduction passage walls 1ab, 1ab are formed as part of an integral casting that constitutes the oil pan 1. Therefore, the oil pan 1 has high rigidity and is resistant to vibration, and is less likely to emit engine noise such as explosions.

[0019] As shown in FIG. 1A, the pair of oil inlets 3a, 3a of the pair of oil introduction passages 3, 3 are located in the center of the oil pan 1 in the longitudinal direction, and as shown in FIG. 1B, they open to the outer lateral sides of the lower part of the pair of oil introduction passage walls 1ab, 1ab at a position facing the inner bottom of the oil pan 1.

[0020] According to this engine (12), when the engine is tilted in the longitudinal or lateral direction, air is hardly drawn in through the oil inlets (3a) of the pair of oil introduction passages (3), (3), and the engine has high tilting performance.

[0021] As shown in Figure 2(B), the oil pan 1 is provided with a filter chamber 5 that connects the pair of oil introduction passages 3, 3 with the oil pump 4. As shown in Figure 2(A), an oil filter 6 is housed in the filter chamber 5. Arrows 25 in Figures 2(A) and 2(B) indicate the flow of oil.

[0022] According to this engine (12), there is no need to provide an oil filter at the oil inlet (3a) shown in Figures 1(B) and 2(B), so a wide oil passage area can be ensured for the pair of oil inlets (3a) (3a).

[0023] 1(A) and 2(A), the filter chamber 5 is surrounded by a filter chamber peripheral wall 5a. The filter chamber peripheral wall 5a protrudes upward from the center wall 1aa and the pair of oil introduction passage walls 1ab, 1ab along the oil pan peripheral wall 1b at one end of the oil pan bottom wall 1a in the front-to-rear direction, and is formed as part of an integral casting that constitutes the oil pan 1.

[0024] According to this engine, the filter chamber peripheral wall (5a) can increase the rigidity of the oil pan (1).

[0025] As shown in Figure 2(A), the upper side of the filter chamber 5 is closed by a top cover 5b, and the oil filter 6 is formed in a flat shape. As shown in Figure 1(A), the filter chamber peripheral wall 5a is formed in a horizontally elongated rectangular shape in a plan view, and as shown in Figure 2(A), it has an intermediate step surface 5aa and an upper end surface 5ab at the middle position and the upper end position in the height direction of the filter chamber 5. The peripheral portion 6a of the oil filter 6 is placed and fixed on the intermediate step surface 5aa, and the peripheral portion 5ba of the top cover 5b is placed and fixed on the upper end surface 5ab.

[0026] This engine 12 allows for easy installation of the oil filter 6 in the filter chamber 5. A horizontally elongated rectangular gasket 5c is sandwiched between the upper end surface 5ab of the filter chamber 5 and the peripheral edge 5ba of the top cover 5b to seal the gap between them.

[0027] As shown in Figures 6 and 7, this engine 12 is equipped with an exhaust gas treatment case support structure that provides vibration-damping support for the exhaust gas treatment case 15 above the cylinder head cover 14. The axial length direction of the crankshaft 2 is the front-to-rear direction, and in the front-to-rear direction, the engine cooling fan 16 side is the front side and the flywheel housing 13 side is the rear side. The exhaust gas treatment case 15 is vibration-damping supported by a front vibration-damping rubber 18a mounted on the front support stay 18 shown in Figures 5(A) and 5(B) and rear vibration-damping rubber 19a mounted on the rear support stay 19 shown in Figures 5(C) and 5(D). As shown in Figure 8, when viewed in the front-to-rear direction, the front support stay (18) is disposed within a fan rotation area (16b) surrounded by a rotation locus (16a) of the outer periphery of the axial flow engine cooling fan (16).

[0028] As shown in Figures 6 and 7, with this engine (12), the support for the exhaust gas treatment case (15) is a front support stay (18) attached to the cylinder head (17) and a rear support stay (19) attached to the flywheel housing (13), making it easy to maintain engine parts from the side of the engine.

[0029] Furthermore, as shown in Figures 6 and 7, with this engine (12), the support for the exhaust gas treatment case (15) is a front support stay (18) attached to the cylinder head (17) and a rear support stay (19) attached to the flywheel housing (13), so that the support for the exhaust gas treatment case (15) can be made smaller.

[0030] Furthermore, as shown in Figure 8, with this engine (12), when viewed in the longitudinal direction, the front support stay (18) is disposed within a fan rotation area (16b) surrounded by the rotation locus (16a) of the outer periphery of the axial flow engine cooling fan (16). Therefore, heat transferred from the cylinder head (17) to the front support stay (18) is dissipated into the cooling air of the engine cooling fan (16) and is less likely to be transferred to the front vibration isolation rubber (18a) shown in Figures 5(A) and (B), thereby suppressing thermal deterioration of the front vibration isolation rubber (18a).

[0031] As shown in Figure 4(A), a support plate (20) is attached to the underside of the exhaust gas treatment case (15), and as shown in Figures 5(A) and 5(C), the support plate (20) is supported by the front vibration-isolating rubber (18a) and the rear vibration-isolating rubber (19a) (19a).

[0032] With this engine (12), the vibration-proof support suppresses vibration of the exhaust gas treatment case (15) shown in Figure 4(A), making it less likely that the exhaust gas treatment case (15) or the exhaust gas treatment device housed therein will be damaged by vibration of the engine (12).

[0033] The width direction of the engine, which is perpendicular to the fore-and-aft direction, is defined as the lateral direction. As shown in Figure 8, the front support stay (18) is disposed in the front of the engine (12) at the lateral center of the engine (12), and as shown in Figure 5(A), a single front rubber support seat (18b) is mounted on the front support stay (18), and the front vibration-isolating rubber (18a) is mounted on the front rubber support seat (18b).

[0034] As shown in Figure 7, the rear support stay (19) is arranged on the rear side of the engine (12), and as shown in Figure 5(C), a pair of left and right rear rubber receiving seats (19b) (19b) are placed on the rear support stay (19), and a pair of left and right rear vibration-isolating rubbers (19a) (19a) are placed on the pair of left and right rear rubber receiving seats (19b) (19b).

[0035] According to this engine (12), the exhaust gas treatment case (15) is stably supported by three points, that is, the single front vibration isolating rubber (18a) and the pair of left and right rear rubber receiving seats (19b), (19b).

[0036] As shown in Figures 5(A) and (B), the single front rubber support seat (18b) has a cylindrical front rubber support seat peripheral wall (18c) that surrounds the front vibration-damping rubber (18a) from the periphery, and as shown in Figures 5(C) and (D), the pair of left and right rear rubber support seats (19b) (19b) have a pair of left and right cylindrical rear rubber support seat peripheral walls (19c) (19c) that respectively surround the pair of left and right rear vibration-damping rubbers (19a) (19a) from the periphery.

[0037] As shown in Figures 5(A) and 5(B), the engine 12 is provided with a single front semicircular stopper 18d and, as shown in Figures 5(C) and 5(D), a pair of left and right rear quarter-circular stoppers 19d, 19d, on the underside of the support plate 20. As shown in Figure 5(B), the single front semicircular stopper 18d faces from the rear, with a semicircular gap 18e held in the front rubber seat peripheral wall 18c. As shown in Figure 5(D), a space (19g) is provided between the pair of left and right rear rubber seat peripheral walls (19c)(19c), and the pair of left and right rear quarter-circular stoppers (19d)(19d) maintain quarter-circular gaps (19e)(19e) with the pair of left and right rear rubber seat peripheral walls (19c)(19c) and face the space (19g) from the diagonally front side.

[0038] With this engine (12), the vibration amplitude around the entire circumference of the exhaust gas treatment case (15) can be limited with a small number of stoppers consisting of a single front semicircular arc stopper (18d) and a pair of rear quarter-circular arc stoppers (19d) (19d) on the left and right.

[0039] As shown in Figures 5(A) and 5(C), the support plate (20) faces the single front rubber seat peripheral wall (18c) and the pair of rear rubber seat peripheral walls (19c) and (19c) with upper and lower gaps (18f) and (19f) therebetween.

[0040] With this engine (12), when the exhaust gas treatment case (15) descends, the support plate (20) is received by the front rubber seat peripheral wall (18c) and the rear rubber seat peripheral wall (19c) (19c), thereby stopping the descent of the exhaust gas treatment case (15) and preventing the support plate (20) from colliding with the cylinder head cover (14).

[0041] As shown in Figure 5(A), the front vibration-damping rubber (18a) has a pair of upper and lower front rubber portions (18aa) (18aa), and as shown in Figure 4(B), the support plate (20) has a front clamping portion (20a), and as shown in Figure 5(A), the front clamping portion (20a) is supported by being clamped from above and below by the pair of upper and lower front rubber portions (18aa) (18aa).

[0042] With this engine (12), when the exhaust gas treatment case (15) vibrates up and down, the front clamping portion (20a) is supported by a pair of upper and lower front rubber portions (18aa) (18aa), making it less likely that the front clamping portion (20a) will be damaged by the vibrations.

[0043] As shown in Figure 5(C), the pair of left and right rear vibration-damping rubbers (19a)(19a) each have a pair of upper and lower rear rubber portions (19aa)(19aa), and as shown in Figure 4(B), the support plate (20) has a pair of left and right rear clamping portions (20b), and as shown in Figure 5(C), the pair of left and right rear clamping portions (20b) are supported by being clamped from above and below by the pair of upper and lower rear rubber portions (19aa)(19aa).

[0044] According to this engine (12), when the exhaust gas treatment case (15) vibrates up and down, the rear clamping portion (20b) is received by the pair of upper and lower rear rubber portions (19aa) (19aa), so that the rear clamping portion (20b) is less likely to be damaged by the vibrations.

[0045] As shown in Figure 4(B), the support plate 20 has a front clamping portion 20a and a pair of left and right rear clamping portions 20b, 20b between which a front mounting plate portion 20c and a rear mounting plate portion 20d are attached to the exhaust gas treatment case 15, and a pair of left and right openings 20e, 20e are provided between the front mounting plate portion 20c and the rear mounting plate portion 20d. The support plate 20 is made of casting, and the pair of left and right openings 20e, 20e contribute to its weight reduction.

[0046] (1)...oil pan, (1a)...oil pan bottom wall, (1aa)...mid-height wall, (1ab)...oil introduction passage wall, (1b)...oil pan peripheral wall, (2)...crankshaft, (3)...oil introduction passage, (3a)...oil inlet, (4)...oil pump, (5)...filter chamber, (5a)...filter chamber peripheral wall, (5aa)...middle step surface, (5ab)...upper end surface, (5b)...top cover, (5ba)...peripheral portion, (6)...oil filter, (6a)...peripheral portion, (7)...cylinder block, (12)...engine, (13)...flywheel housing.

Claims

1. An oil pan for an engine, comprising: an oil pan bottom wall and an open-topped oil pan peripheral wall; the axial direction of the crankshaft is the front-to-rear direction; the width direction of the engine, which is perpendicular to the front-to-rear direction, is the horizontal direction; the rectangular oil pan has its long sides aligned along the front-to-rear direction and its short sides aligned along the horizontal direction; the oil pan bottom wall has an upwardly convex height wall extending in the front-to-rear direction at the horizontal center of the oil pan bottom wall; a pair of oil introduction passage walls extending in the front-to-rear direction along both lateral sides of the height wall; and a pair of oil introduction passages provided within the pair of oil introduction passage walls; the height wall and the pair of oil introduction passage walls being formed as part of an integral casting that constitutes the oil pan.

2. An oil pan for an engine as described in claim 1, wherein a pair of oil inlets of the pair of oil introduction passages are located in the center of the oil pan in the fore-and-aft direction, and open to the outside of the lower lateral sides of the pair of oil introduction passage walls, at a position facing the inner bottom of the oil pan.

3. An engine oil pan as described in claim 2, further comprising a filter chamber that connects the pair of oil introduction passages with an oil pump, and an oil filter is housed in the filter chamber.

4. An oil pan for an engine as described in claim 3, wherein the filter chamber is surrounded by a filter chamber peripheral wall, and the filter chamber peripheral wall protrudes upward from the mid-height wall and the pair of oil introduction passage walls along the oil pan peripheral wall at one end side of the bottom wall in the fore-and-aft direction of the oil pan, and is formed as part of an integral casting that constitutes the oil pan.

5. An engine oil pan as claimed in claim 4, wherein the upper side of the filter chamber is closed with an upper lid, the oil filter is formed in a flat shape, the peripheral wall of the filter chamber is formed in a horizontally elongated rectangular shape in a plan view, and has an intermediate step surface and an upper end surface at the middle position and upper end position in the height direction of the filter chamber, and the peripheral portion of the oil filter is placed and fixed on the intermediate step surface, and the peripheral portion of the upper lid is placed and fixed on the upper end surface.

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