Internal combustion engine

Abstract

To secure visibility for checking a sealed state of mating surfaces of members constituting an internal combustion engine.SOLUTION: A cover member 4, which is arranged so as to cover the lower part of a lower oil pan 3, has a joint surface covering part 13 that covers a joint surface between an upper oil pan 2 and the lower oil pan 3. A distance between a pair of first bolts 15, 15 that fix the joint surface covering part 13 to the upper oil pan 2 is set to a predetermined length so that the joint surface can be seen from between the pair of first bolts 15, 15 when the cover member is folded back between the pair of first bolts 15, 15.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an internal combustion engine. [Background technology]

[0002] For example, Patent Document 1 discloses a configuration in which multiple sound-insulating covers are attached to an internal combustion engine (engine) that is composed of multiple components such as a cylinder block, an upper oil pan attached to the bottom of the cylinder block, and a lower oil pan attached to the bottom of the upper oil pan.

[0003] In Patent Document 1, a sound insulating cover is attached to suppress noise reaching the passenger compartment located behind the internal combustion engine.

[0004] In an internal combustion engine, mating surfaces between components that constitute the engine itself, such as the mating surfaces between the upper oil pan and the lower oil pan, are sealed liquid-tight. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-236091 Summary of the Invention [Problem to be solved by the invention]

[0006] However, Patent Document 1 does not mention anything about visibility for inspecting the sealing condition of the mating surfaces between components that make up the internal combustion engine, and there is a risk that the mating surfaces will be covered by the sound-insulating cover and the sealing condition will not be visible.

[0007] That is, when a sound insulating cover is attached to an internal combustion engine, there is room for further improvement in terms of ensuring visibility for checking the sealing state of the mating surfaces of the components that make up the internal combustion engine. [Means for solving the problem]

[0008] The internal combustion engine of the present invention includes a first housing attached to a lower portion of an internal combustion engine body, a second housing attached to a lower portion of the first housing, a cover member arranged to cover the lower portion of the second housing, and a plurality of fixing members fixing the cover member to the first housing. The cover member has a joint surface covering portion that covers the joint surface, and the plurality of fixing members include a pair of first fixing members that are adjacent to each other in the circumferential direction of the cover member and fix the joint surface covering portion to the first housing. The distance between the pair of first fixing members is set to a predetermined length such that the joint surface can be seen from between the pair of first fixing members when the cover member is folded back between the pair of first fixing members. [Effects of the Invention]

[0009] According to the present invention, the sealing state at the joint surface between the first housing and the second housing can be easily visually confirmed. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a lower structure of an internal combustion engine to which the present invention is applied, in a state where a cover member is not attached. [Figure 2] 1 is a perspective view showing a lower structure of an internal combustion engine according to the present invention; [Figure 3] FIG. [Figure 4] FIG. 4 is a perspective view of a cover member of the internal combustion engine as viewed from below. [Figure 5] FIG. 3 is a perspective view of a cover member of the internal combustion engine as viewed from above. [Figure 6] 6 is a cross-sectional view taken along line AA in FIG. 5. [Figure 7] FIG. 7 is a cross-sectional view taken along line BB in FIG. 6. [Figure 8] FIG. 6 is a cross-sectional view taken along line CC in FIG. 5 . DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a perspective view showing the lower structure of an internal combustion engine 1 to which the present invention is applied. Fig. 2 is a perspective view showing the lower structure of an internal combustion engine 1 according to the present invention, showing a state in which a cover member 4 (described later) is attached to the lower part of the internal combustion engine body. In this specification, lower and lower refer to the lower side of the vehicle when the internal combustion engine 1 is mounted on the vehicle, and upper and upper refer to the upper side of the vehicle when the internal combustion engine 1 is mounted on the vehicle.

[0012] The internal combustion engine 1 is an in-line multi-cylinder internal combustion engine, and has an upper oil pan 2, a lower oil pan 3, a cover member 4, and a plurality of bolts 12 (see Figures 3 to 8 described below) at the bottom of the internal combustion engine body, which is made up of a metal cylinder head (not shown) and a cylinder block (not shown), etc.

[0013] The upper oil pan 2 corresponds to a first housing, is made of, for example, a metal material, and is located below the cylinder block and attached to the bottom of the cylinder block.

[0014] The lower oil pan 3 corresponds to the second housing and is made of, for example, a metal material, is located below the upper oil pan 2, and is attached to the lower part of the upper oil pan 2 via a sealing material (not shown). The sealing material is, for example, a liquid seal gasket, and is applied (placed) between the upper oil pan 2 and the lower oil pan 3 to liquid-tightly seal the joint surface (mating surface) 5 between them.

[0015] The cover member 4 is made of nonwoven fabric and is arranged to cover the lower part of the lower oil pan 3. The cover member 4 is fixed to the upper oil pan 2 with bolts 12, which correspond to fixing members. The cover member 4 has a drain hole 6 formed in its center. The drain hole 6 is formed in a position corresponding to the location of the drain plug 7 attached to the bottom of the lower oil pan 3 so that the drain plug 7 is exposed. The drain plug 7 is removed when draining oil from the lower oil pan 3.

[0016] The cover member 4, which is a main part of the present invention, will be described with reference to Figs. 3 to 8. Fig. 3 is a bottom view of the cover member 4. Fig. 4 is a perspective view of the cover member 4 seen from below. Fig. 5 is a perspective view of the cover member 4 seen from above. Fig. 6 is a cross-sectional view taken along line AA in Fig. 5. Fig. 7 is a cross-sectional view taken along line BB in Fig. 6. Fig. 8 is a cross-sectional view taken along line CC in Fig. 5.

[0017] The cover member 4 is formed into a dish shape by press molding and has sound insulation properties. The cover member 4 is formed into a predetermined shape by, for example, impregnating a sheet material made of nonwoven fabric with a thermosetting resin and then hot pressing it.

[0018] During press molding, the cover member 4 is formed to have a thick, relatively soft portion and a thin, relatively hard portion, as shown in Fig. 5. In Fig. 5, the area of ​​the cover member 4 where the dot pattern is drawn is the hard portion of the cover member 4. In Fig. 5, the area of ​​the cover member 4 where the dot pattern is not drawn is the soft portion of the cover member 4.

[0019] As shown in Figures 3 and 4, the cover member 4 has mounting holes 11 formed in multiple locations (five locations in this embodiment) on its outer periphery. The cover member 4 is fixed to the upper oil pan 2 with bolts 12 (see Figure 5) inserted into the mounting holes 11. The cover member 4 has a joint surface covering portion 13 that covers the joint surface 5 from the outside. The joint surface covering portion 13 is located on or near the outer periphery of the cover member 4, facing the joint surface 5 at a predetermined distance. The joint surface covering portion 13 is located on the outer periphery side of the joint surface 5.

[0020] The cover member 4 has a joint surface covering portion 13 formed continuously along the circumferential direction of the cover member 4 on the outer circumferential edge and in the vicinity of the outer circumferential edge, excluding a range R (see FIGS. 3 and 5). That is, the cover member 4 has the joint surface covering portion 13 formed continuously on the outer circumferential edge and in the vicinity of the outer circumferential edge excluding the range R.

[0021] As shown in FIG. 5 , the multiple bolts 12 include two sets of first bolts 15, 15 that are adjacent to each other in the circumferential direction of the cover member 4 and correspond to a pair of first fixing members that fix the joint surface covering portion 13 to the upper oil pan 2. That is, the multiple bolts 12 include a pair of first bolts 15a, 15b that are adjacent to each other in the circumferential direction of the cover member 4 and that fix the joint surface covering portion 13a to the upper oil pan 2, and a pair of first bolts 15b, 15c that fix the joint surface covering portion 13b to the upper oil pan 2. The pair of first bolts 15, 15 fix the cover member 4 to the upper oil pan 2 at a position where a first property portion 19 (described below) between the pair of first bolts 15, 15 is not linear along the circumferential direction of the cover member 4. The bolts 12 fix the first property portion 19 (described below) of the cover member 4 to the upper oil pan 2.

[0022] The joint surface covering portion 13a is formed on the outer periphery of a section S1 sandwiched between the first bolts 15a and 15b in a plan view of the cover member 4. Section S1 is a section on a reference line L1, which will be described later. The joint surface covering portion 13b is formed on the outer periphery of a section S2 sandwiched between the first bolts 15b and 15c in a plan view of the cover member 4. Section S2 is a section on a reference line L2, which will be described later.

[0023] The multiple mounting holes 11 are adjacent to each other in the circumferential direction of the cover member 4 and include two pairs of first mounting holes 16, 16 into which a pair of first bolts 15, 15 are inserted to secure the joint surface covering portion 13 to the upper oil pan 2. That is, the multiple mounting holes 11 are adjacent to each other in the circumferential direction of the cover member 4 and include a pair of first mounting holes 16a, 16b into which a pair of first bolts 15a, 15b are inserted to secure the joint surface covering portion 13a to the upper oil pan 2, and a pair of first mounting holes 16b, 16c into which a pair of first bolts 15b, 15c are inserted to secure the joint surface covering portion 13b to the upper oil pan 2. The pair of first mounting holes 16, 16 are positioned such that a first characteristic portion 19 (described below) between the pair of first mounting holes 16, 16 is not linear along the circumferential direction of the cover member 4. The mounting holes 11 are formed in the first characteristic portion 19 (described below).

[0024] In a plan view of the cover member 4, the distance between the pair of first bolts 15a, 15b (the length of section S1) is set to a predetermined length such that when an operator peels back the cover member 4 between the pair of first bolts 15a, 15b using a finger or the like, the joint surface 5 becomes visible from between the pair of first bolts 15a, 15b. In addition, in a plan view of the cover member 4, the distance between the pair of first bolts 15b, 15c (the length of section S2) is set to a predetermined length such that when an operator peels back the cover member 4 between the pair of first bolts 15b, 15c using a finger or the like, the joint surface 5 becomes visible from between the pair of first bolts 15b, 15c.

[0025] In other words, the cover member 4 is set to a predetermined length in plan view such that the distance between the first mounting holes 16a and 16b (the length of section S1) is a length that allows the joint surface 5 to be seen from between the pair of first mounting holes 16a and 16b when an operator uses a finger or the like to peel back the cover member 4 between the pair of first mounting holes 16a and 16b. Furthermore, the cover member 4 is set to a predetermined length in plan view such that the distance between the first mounting holes 16b and 16c (the length of section S2) is a length that allows the joint surface 5 to be seen from between the pair of first mounting holes 16b and 16c when an operator uses a finger or the like to peel back the cover member 4 between the pair of first mounting holes 16b and 16c.

[0026] 3, the cover member 4 has an overhang portion 18 that is located on the outer circumferential side of the cover member 4 relative to a reference line L that connects the pair of first bolts 15, 15 in a plan view. In other words, the cover member 4 has an overhang portion 18 that is located on the outer circumferential side of the cover member 4 relative to a reference line L that connects the pair of first mounting holes 16, 16 in a plan view.

[0027] That is, in a plan view, the cover member 4 has an overhang portion 18a that is located on the outer circumferential side of the cover member 4 relative to a reference line L1 that connects the pair of first bolts 15a, 15b, and an overhang portion 18b that is located on the outer circumferential side of the cover member 4 relative to a reference line L2 that connects the pair of first bolts 15b, 15c. In other words, in a plan view, the cover member 4 has an overhang portion 18a that is located on the outer circumferential side of the cover member 4 relative to a reference line L1 that connects the first mounting holes 16a and 16b. In addition, in a plan view, the cover member 4 has an overhang portion 18b that is located on the outer circumferential side of the cover member 4 relative to a reference line L2 that connects the first mounting holes 16b and 16c.

[0028] The overhang portion 18 includes portions other than the outer peripheral edge of the cover member 4, and includes at least both the first property portion 19 and the second property portion 20. That is, in the cover member 4, the reference line L is set so as not to follow the outer peripheral edge of the cover member 4.

[0029] The overhang portion 18 is the portion that is mainly turned up when an operator hooks his / her fingers or the like around the outer periphery of the cover member 4 between the pair of first bolts 15, 15 and turns it up.

[0030] As shown in FIG. 5 , the overhang portion 18 has a first property portion 19 and a second property portion 20 with different properties. The first property portion 19 is harder than the second property portion 20 and is less susceptible to elastic deformation than the second property portion 20. The second property portion 20 is softer than the first property portion 19 and is more susceptible to elastic deformation than the first property portion 19. The first property portion 19 is a relatively hard portion that becomes thinner and denser during press molding. In other words, the first property portion 19 is a portion that is compressed to a large extent during press molding of the sheet material that forms the base of the cover member 4. The first property portion 19 is formed so as to be continuous around the entire outer periphery of the cover member 4. The first property portion 19 is formed so as to be located outside the second property portion 20. The first property portion 19 also forms the outer periphery of the cover member 4. The second property portion 20 is a portion that becomes relatively thicker and has a lower density during press molding, making it relatively soft. In other words, the second property portion 20 is a portion that is less compressed during press molding of the sheet material that forms the base of the cover member 4. The second property portion 20 is formed adjacent to the inside of the first property portion 19.

[0031] The overhang portion 18 is fixed to the upper oil pan 2 at a first property portion 19 by a pair of first bolts 15, 15. A pair of first mounting holes 16, 16 are formed in the first property portion 19. The pair of first mounting holes 16, 16 are set at positions such that the first property portion 19 between the pair of first mounting holes 16, 16 is not linear in the circumferential direction of the cover member 4.

[0032] As shown in FIGS. 5 to 7, the overhang portion 18a has a first property portion 19 fixed to the upper oil pan 2 by a pair of first bolts 15a and 15b.

[0033] The overhang portion 18a is formed so that the second property portion 20 is continuous between the pair of first bolts 15a, 15b in the circumferential direction of the cover member 4. Therefore, when the overhang portion 18a is turned up, tension is generated in the second property portion 20 so that it is pulled by the first bolts 15a, 15b on both sides.

[0034] The overhang portion 18a has a third property portion 21, which has properties different from those of the second property portion 20, located inside the cover member 4 relative to the second property portion 20. The third property portion 21 is harder than the second property portion 20 and is less susceptible to elastic deformation than the third property portion 21. The third property portion 21 is a portion that becomes relatively thin and denser during press molding, making it relatively hard. In other words, the third property portion 21 is a portion that is largely compressed during press molding of the sheet material that forms the base of the cover member 4.

[0035] The third property portion 21 is formed so as to be continuous along the circumferential direction of the cover member 4. The third property portion 21 is formed so as to be thinner than the second property portion 20.

[0036] 5 and 8, overhang portion 18b is formed so that thicker and thinner portions alternate along reference line L2. In addition, in overhang portion 18b, a step is formed along thick dashed line P in FIG. 5. When an operator uses his or her fingers to flip up cover member 4 between the pair of first bolts 15b, 15c, the step formed along thick dashed line P becomes a factor that makes it easier to flip up.

[0037] In the internal combustion engine 1 of the embodiment described above, the sealing condition at the joint surface 5 between the upper oil pan 2 and the lower oil pan 3 can be easily checked visually.

[0038] In addition, the distance between a pair of adjacent first bolts 15, 15 in the circumferential direction of the cover member 4 is set to a length that allows an operator to manually flip the cover member 4 over and visually check the appearance of the joint surface 5 between the upper oil pan 2 and the lower oil pan 3.

[0039] Therefore, with this configuration, the distance between the pair of first bolts 15, 15 does not become too wide, and the cover member 4 that is flipped up to visually check the joint surface 5 recovers (restores) to its original shape by its own elasticity, thereby ensuring both visibility and maintaining soundproofing properties.

[0040] The cover member 4 is made of nonwoven fabric, so that the worker can easily roll it up by hand.

[0041] When an operator uses his / her fingers or the like to roll up the outer edge of the cover member 4 between the pair of first bolts 15, 15, the overhang portion 18 can be rolled up using the first bolts 15, 15 as a stop point.

[0042] In the cover member 4, the relatively soft second property portion 20 contributes to the rolling up of the overhang portion 18, and the relatively hard first property portion 19 contributes to preventing the overhang portion 18 as a whole from losing its shape.

[0043] The cover member 4 is normally prevented from sagging (drooping) downward by the relatively hard first property portion 19. Furthermore, when an operator applies force between the pair of first bolts 15, 15, the relatively soft second property portion 20 of the cover member 4 deforms, causing the overhang portion 18 to bend and roll downward around the vicinity of the first bolts 15, 15 as a fulcrum, making it possible to easily view the joint surface 5 between the pair of first bolts 15, 15 that is normally covered by the cover member 4.

[0044] The overhang portion 18a has a third property portion 21 inside the second property portion 20. Therefore, in the cover member 4, the relatively soft second property portion 20 contributes to the rolling up of the overhang portion 18a, while the relatively hard first property portion 19 and third property portion 21 prevent the overall shape of the overhang portion 18a. In the cover member 4, the second property portion 20 deforms, causing the overhang portion 18a to bend and roll downward around the first bolts 15a, 15b, while the third property portion 21 can suppress deformation of the second property portion 20 near the center between the pair of first bolts 15, 15. Furthermore, when the force applied by the worker between the pair of first bolts 15a, 15b at the overhang portion 18a of the cover member 4 is removed, the shape of the second property portion 20 is more likely to recover (restore) to cover the joint surface 5, using the third property portion 21 as a base (foothold), making it even easier to ensure both visibility and soundproofing.

[0045] The cover member 4 is formed such that the second property portion 20 is continuous between the pair of first bolts 15a, 15b in the circumferential direction of the cover member 4 at the overhang portion 18a. Therefore, when an operator applies a downward force between the pair of first bolts 15a, 15b, the second property portion 20 absorbs any misalignment between the first property portion 19 and the third property portion 21, and the third property portion 21 does not hinder the deflection of the first property portion 19.

[0046] The cover member 4 has the first property portion 19, which is the hard portion, fixed to the upper oil pan 2 by the bolts 12, making it easy to hold onto the upper oil pan 2 and making it easy to peel back the outer edge when visually inspecting the joint surface 5.

[0047] It should be noted that, although it is not easy, the joining surface covering portion 13 can be rolled up by hand or the like by an operator even in the portions other than the joining surface covering portions 13a and 13b located outside the sections S1 and S2.

[0048] Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention.

[0049] For example, the cover member 4 may have the joint surface covering portion 13 formed continuously over the entire circumference in the circumferential direction of the cover member 4. [Explanation of symbols]

[0050] 1...Internal combustion engine 2...Upper oil pan 3...Lower oil pan 4...Cover member 5…Joint surface 6...Drain hole 7...Drain plug 11...Mounting hole 12...Volts 13... Bonding surface coating part 15...First bolt 16...First mounting hole 18...Overhang 19...First property part 20…Second property part 21…Third property part

Claims

1. a first housing attached to a lower portion of an internal combustion engine body; a second housing attached to a lower portion of the first housing; a cover member arranged to cover the lower portion of the second housing; and a plurality of fixing members for fixing the cover member to the first housing; the cover member has a joint surface covering portion that covers the joint surfaces of the first housing and the second housing, The plurality of fixing members include a pair of first fixing members that are adjacent to each other in the circumferential direction of the cover member and fix the joint surface covering portion to the first housing, an internal combustion engine characterized in that the distance between the pair of first fixing members is set to a predetermined length such that, when the cover member is flipped up between the pair of first fixing members, the joint surface can be seen from between the pair of first fixing members.

2. 2. The internal combustion engine according to claim 1, wherein the cover member is made of nonwoven fabric.

3. 3. The internal combustion engine according to claim 2, wherein the cover member is press-molded.

4. 2. The internal combustion engine according to claim 1, wherein the cover member has an overhang portion that is located on the outer circumferential side of the cover member relative to a reference line connecting the pair of first fixing members in a plan view.

5. The overhang portion has a first property portion and a second property portion having different properties, 5. The internal combustion engine according to claim 4, wherein the first property portion, which is harder than the second property portion, is formed so as to be positioned outside the second property portion.

6. 6. The internal combustion engine according to claim 5, wherein the overhang portion has a third property portion harder than the second property portion and located inside the second property portion.

7. 7. The internal combustion engine according to claim 6, wherein the second property portion is formed so as to be continuous between the pair of first fixing members in the circumferential direction of the cover member.

8. 8. The internal combustion engine according to claim 7, wherein the cover member is press-molded, and the first property portion and the third property portion are formed to have a thinner wall thickness than the second property portion.

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