Noise insulation structure for automobile engine

Abstract

To improve sound insulation while allowing visual check of oil bleeding at a boundary 7 with a lower oil pan.SOLUTION: A side surface of an upper oil pan (2) located above a boundary (7) between the upper oil pan (2) and a lower oil pan is covered with a right front sound insulation cover (12) and a right rear sound insulation cover (13), the bottom surface of the lower oil pan and a part of the side surface of the upper oil pan (2) are covered with one bottom surface sound insulation cover (11), and at least a part of the boundary (7) is exposed between the right front sound insulation cover (12) and the right rear sound insulation cover (13) and the bottom surface sound insulation cover (11) so as to be visible.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a sound insulation structure for an automobile engine, which is provided with a sound insulation member covering an oil pan at the bottom of the engine. [Background technology]

[0002] A known oil pan installed at the bottom of an automobile engine is one that combines an upper oil pan, typically made of a metal casting, with a lower oil pan, typically made of a metal plate. Another known oil pan configuration includes a sound-insulating cover that covers the oil pan to block noise radiated from the oil pan at the bottom of the engine.

[0003] Patent Document 1 discloses a configuration in which the underside and periphery of a lower oil pan are covered with a single sound insulating cover. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-236091 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration of Patent Document 1, the rectangular, deep-dish sound-insulating cover covers the lower oil pan, making it impossible to visually inspect the joint boundary between the lower oil pan and the upper oil pan from the outside, and therefore making it impossible to visually inspect for oil seepage at the joint boundary due to seal deterioration or the like. [Means for solving the problem]

[0006] This invention is a sound insulation structure for an automobile engine, which has an upper oil pan attached to the lower edge of a skirt portion of the engine, and a lower oil pan that serves as an oil reservoir attached to a part of the bottom surface of the upper oil pan, a side surface of the upper oil pan above a boundary between the upper oil pan and the lower oil pan is covered with a first sound-proofing member; a bottom surface of the lower oil pan and a side surface of the upper oil pan are covered with a second sound-proofing member; At least a part of the boundary is exposed and visible between the first and second sound-insulating members. [Effects of the Invention]

[0007] According to this invention, the first sound-insulating member and the second sound-insulating member are basically arranged above and below the boundary, and sound insulation to the sides of the oil pan can be achieved while keeping the boundary visible. Furthermore, the entire bottom surface of the lower oil pan and part of the side surface of the upper oil pan are covered by a single second sound-insulating member, thereby achieving high sound-insulating performance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 4 is a perspective view of the oil pan without the sound insulating cover, viewed from diagonally below. [Figure 2] FIG. 2 is a perspective view of an oil pan equipped with a sound insulating cover, viewed obliquely from below. [Figure 3] FIG. 1 is a bottom view of an oil pan with a sound-insulating cover. [Figure 4] FIG. 4 is a side view showing the right side of the oil pan equipped with a sound insulating cover. [Figure 5] FIG. 2 is a perspective view of the left side of the oil pan equipped with a sound insulating cover, viewed obliquely from above. [Figure 6] FIG. 2 is a side view showing the left side of the oil pan equipped with a sound insulating cover. [Figure 7] FIG. 1 is a rear view of the oil pan with the sound insulation cover. [Figure 8] FIG. 2 is a perspective view of an oil pan equipped with a sound insulating cover, as viewed obliquely from the front. [Figure 9] A close-up of the key parts of the left side of the oil pan showing the opening peeking into the boundary. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will now be described in detail with reference to the drawings. First, referring to FIG. 1, an engine oil pan 1, which is the subject of the sound-insulating structure of the present invention, will be described. The oil pan 1 is provided at the bottom of the engine to collect lubricating oil supplied to various parts of the engine and is composed of two components: an upper oil pan 2 and a lower oil pan 3. FIG. 1 is a perspective view of the oil pan 1, viewed obliquely from below. The upper oil pan 2 is formed into a deep dish shape by die-casting an aluminum alloy, for example, and has relatively high rigidity. The upper oil pan 2 is attached to the lower edge of the engine skirt (not shown) at its upper flange 4. The upper oil pan 2 has an opening in a portion of its bottom surface, and a lower oil pan 3, which serves as an oil reservoir, is attached to cover this opening. The lower oil pan 3 is formed by press-forming a steel plate and has a relatively shallow dish shape. The lower oil pan 3 is equipped with an oil drain section 5 for discharging the lubricating oil.

[0010] The lower oil pan 3 is joined at its periphery to the periphery of the opening of the upper oil pan 2 and is fixed to the upper oil pan 2 with a plurality of bolts (not shown). A seal member, such as a liquid gasket, is provided at a boundary 7 between the joined lower oil pan 3 and upper oil pan 2. This boundary 7 is provided along a single plane.

[0011] The engine shown in the figure is, for example, an in-line three-cylinder engine, with the right side of FIG. 1 corresponding to the front end of the engine and the left side corresponding to the rear end of the engine. In the following description, the side of the oil pan 1 on the right side when viewed from the rear of the engine will be referred to as the right side, and the side of the oil pan 1 on the left side will be referred to as the left side. Therefore, FIG. 1 shows the bottom and right side of the oil pan 1, including the lower oil pan 3. The lower oil pan 3 is positioned toward the front in the fore-and-aft direction of the engine.

[0012] 2 to 8 show oil pan 1 fitted with sound-insulating covers 11 to 14. In this embodiment, the sound-insulating covers include four sound-insulating members: bottom sound-insulating cover 11, right front sound-insulating cover 12, right rear sound-insulating cover 13, and left sound-insulating cover 14. All of these sound-insulating covers 11 to 14 are made by hot-pressing nonwoven fabric impregnated with thermosetting resin into a desired shape, with bottom sound-insulating cover 11 corresponding to the "second sound-insulating member" in the claims, and right front sound-insulating cover 12, right rear sound-insulating cover 13, and left sound-insulating cover 14 corresponding to the "first sound-insulating member" in the claims.

[0013] FIG. 2 is a perspective view of the oil pan 1, seen obliquely from below, showing the bottom sound-insulating cover 11 covering the lower oil pan 3, and the right front sound-insulating cover 12 and right rear sound-insulating cover 13 covering the right side of the upper oil pan 2. FIG. 3 is a bottom view of the oil pan 1 with the sound-insulating covers attached, and FIG. 4 is a right side view. As in FIG. 1, in FIGS. 2 to 4, the right side of the drawings corresponds to the front end of the engine. As shown in FIGS. 2 to 4, the bottom sound-insulating cover 11 covers the entire bottom surface of the lower oil pan 3 and further extends rearward to the rear end of the oil pan 1 to cover a portion (rear portion) of the bottom surface of the upper oil pan 2. In other words, the bottom sound-insulating cover 11 has a lower oil pan corresponding portion 11a that covers the lower oil pan 3 and an upper oil pan corresponding portion 11b that covers a portion of the bottom surface of the upper oil pan 2, with the lower oil pan corresponding portion 11a projecting downward relatively. 3, a substantially triangular or trapezoidal opening 15 is formed in lower oil pan corresponding portion 11a in correspondence with oil drain portion 5 of lower oil pan 3. In this way, good sound insulation is achieved by covering the entire lower oil pan 3, which generates relatively large amounts of noise, with a single bottom sound-insulating cover 11.

[0014] 4, on the right side of oil pan 1, parts of bottom sound-insulating cover 11 (shown as upward extensions 11c and 11d) extend slightly above boundary 7 between lower oil pan 3 and upper oil pan 2. Upward extensions 11c and 11d correspond to the "upper oil pan side wall" in the claims, and cover parts of the side surfaces of upper oil pan 2 to provide sound insulation.

[0015] As shown in Figure 2, the bottom sound-insulating cover 11 is fixed to the upper oil pan 2 using a plurality of (e.g., five) general resin clips 21 that are fixed by being press-fitted into holes. The insertion direction of each of these resin clips 21 is set to be from below the engine to above it. This makes it easy to attach and detach the bottom sound-insulating cover 11 during vehicle assembly and maintenance work.

[0016] As shown in FIGS. 4 and 2, a right front sound insulation cover 12 and a right rear sound insulation cover 13 are attached to the right side of the upper oil pan 2. The right front sound insulation cover 12 covers the right side of the upper oil pan 2, closer to the front. In particular, the lower edge of the right front sound insulation cover 12 is positioned above the boundary 7 and is configured so as not to overlap with the upper extensions 11c and 11d of the bottom sound insulation cover 11. Therefore, a window-like opening 22 (see FIG. 4) remains between the upper edge of the bottom sound insulation cover 11 and the lower edge of the right front sound insulation cover 12, between the two upper extensions 11c and 11d, and the boundary 7 is exposed through this opening 22. In other words, the boundary 7 on the right side can be seen through this opening 22. In this way, the exposed portion that makes the boundary 7 visible between the right front sound insulation cover 12 and the bottom sound insulation cover 11 is provided to extend along the boundary 7.

[0017] The right rear sound insulating cover 13 covers the right side surface near the rear of the upper oil pan 2. The right rear sound insulating cover 13 is located at a relatively large upward distance from the boundary 7 and does not obstruct the view of the boundary 7.

[0018] The right front sound-insulating cover 12 and the right rear sound-insulating cover 13 are each fixed to the right side surface of the upper oil pan 2 using two resin clips 21. The insertion direction of these resin clips 21 is 90° different from the insertion direction of the resin clips 21 for the bottom sound-insulating cover 11, and they are each inserted from the side. Therefore, the right front sound-insulating cover 12 and the right rear sound-insulating cover 13 can be easily attached and detached individually, separately from the bottom sound-insulating cover 11.

[0019] As described above, a relatively large proportion of the surface area of ​​the right side of oil pan 1 is covered by the right front sound-insulating cover 12, the right rear sound-insulating cover 13, and a portion of bottom sound-insulating cover 11 (upper extensions 11c, 11d), which are divided so that boundary 7 is visible. Therefore, good sound insulation is achieved. Furthermore, in addition to the portion of boundary 7 that is directly open to the outside, by looking obliquely through opening 22, etc., it is possible to visually check for oil seepage from the right side of boundary 7 for roughly half of the entire area on the right side of lower oil pan 3.

[0020] 5 and 6 show the left side of the oil pan 1 equipped with a sound-insulating cover. In FIGS. 5 and 6, the left side of the drawings corresponds to the front end of the engine. On the left side, the bottom sound-insulating cover 11 has upward extensions 11e and 11f at its center and rear end. These upward extensions 11e and 11f extend above the boundary 7 between the lower oil pan 3 and the upper oil pan 2, covering part of the left side of the upper oil pan 2. The upward extensions 11e and 11f correspond to the "side wall for the upper oil pan" in the claims, and cover part of the side of the upper oil pan 2 to provide sound insulation.

[0021] 3 is disposed at the upper end of the upward extension 11f, and therefore fixes the upper edge of the bottom sound-insulating cover 11 to the upper oil pan 2 at a position above the boundary 7. Fixing the upper edge of the bottom sound-insulating cover 11 at a relatively high position in this manner makes it less likely that the bottom sound-insulating cover 11 will open up.

[0022] As shown in FIGS. 5 and 6 , a left sound insulation cover 14 is attached to the left side surface of the oil pan 1. This left sound insulation cover 14 covers the vicinity of the center of the left side surface of the lower oil pan 3. In particular, the lower edge of the left sound insulation cover 14 is positioned above the boundary 7 and is configured so as not to overlap with the upper extensions 11e and 11f of the bottom sound insulation cover 11. Therefore, a window-like opening 23 (see FIG. 9 ) remains between the upper edge of the bottom sound insulation cover 11 and the lower edge of the left sound insulation cover 14, between the two upper extensions 11e and 11f, and the boundary 7 is exposed through this opening 23. In other words, the boundary 7 can be visually observed through the opening 23. In this way, the exposed portion that makes the boundary 7 visible between the left sound insulation cover 14 and the bottom sound insulation cover 11 is provided to extend along the boundary 7.

[0023] In particular, the side edge of the bottom sound-insulating cover 11 where the opening 23 is located and the upward extension 11f connected thereto are positioned away from the boundary 7 so as to form a gap between them (see FIG. 7). Therefore, by looking obliquely through the opening 23, an operator can check for the presence or absence of oil seepage at the boundary 7 over an area longer than the length of the opening 23.

[0024] The left sound-insulating cover 14 is fixed to the left side surface of the upper oil pan 2 using two resin clips 21. As with the right front sound-insulating cover 12 and the right rear sound-insulating cover 13, the insertion direction of these resin clips 21 is 90° different from the insertion direction of the resin clips 21 for the bottom sound-insulating cover 11, and each is designed to be inserted from the side. Therefore, the left sound-insulating cover 14 can be easily attached and detached separately from the bottom sound-insulating cover 11.

[0025] In this way, a relatively large proportion of the surface area of ​​the left side of the oil pan 1 is covered by the left sound-insulating cover 14, which is divided so that the boundary 7 is visible, and a portion of the bottom sound-insulating cover 11 (e.g., the upper extension 11f). Therefore, good sound insulation is achieved. Furthermore, in addition to the portion of boundary 7 that is directly open to the outside, by looking obliquely through the opening 23, it is possible to visually check for oil seepage from the left side of the lower oil pan 3 at boundary 7 for roughly half of the entire area.

[0026] Figure 8 is a view of oil pan 1 with a sound-insulating cover as seen from the front. As shown in Figure 8, at the front end of oil pan 1, the upper edge of bottom sound-insulating cover 11 is basically located at a height position lower than boundary 7, making it possible to visually check boundary 7. Furthermore, in the area on the left side of Figure 8 where boundary 7 is covered by upward extension 11d of bottom sound-insulating cover 11, boundary 7 can also be visually checked by looking obliquely through the opening 23 described above.

[0027] Therefore, in the illustrated example, the boundary 7 can be visually checked over the entire periphery of the lower oil pan 3.

[0028] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment and various modifications are possible. [Explanation of symbols]

[0029] 1...Oil pan 2...Upper oil pan 3...Lower oil pan 7…boundary 11...Bottom sound insulation cover 12...Right front sound insulation cover 13...Right rear sound insulation cover 14...Left sound insulation cover 21...Resin clip 22, 23...Opening

Claims

1. A sound insulation structure for an automobile engine, comprising an upper oil pan attached to a lower edge of a skirt portion of the engine, and a lower oil pan serving as an oil reservoir attached to a part of the bottom surface of the upper oil pan, a first sound-proofing member covering a side surface of the upper oil pan above a boundary between the upper oil pan and the lower oil pan; a bottom surface of the lower oil pan and a side surface of the upper oil pan are covered with a second sound-insulating member; At least a part of the boundary is visibly exposed between the first and second sound-insulating members. Sound insulation structure for automobile engines.

2. an upper oil pan side wall portion of the second sound-proofing member covering a side surface of the upper oil pan extends above the boundary in the height direction of the engine and covers an area of ​​the side surface of the upper oil pan where the first sound-proofing member is not present; The sound insulation structure for an automobile engine according to claim 1.

3. The exposed portion that makes the boundary between the first and second sound-insulating members visible is provided so as to extend along the boundary. The sound insulation structure for an automobile engine according to claim 1.

4. the second sound-proofing member is fixed to the upper oil pan via clips at a plurality of fixing points, At least some of the fixing points are provided on the upper oil pan side wall portion extending above the boundary. The sound insulation structure for an automobile engine according to claim 2.

5. The second sound-proofing member is fixed to the upper oil pan via a clip that is inserted upward from below the engine, The first sound-proofing member is fixed to the upper oil pan via a clip that is inserted from the side of the engine. The sound insulation structure for an automobile engine according to claim 1.

6. a portion of the second sound-proofing member that crosses the boundary of the upper oil pan sidewall portion is positioned outwardly away from the boundary to form a gap between the portion and the boundary, An opening is formed in this portion to allow visual observation of the boundary of the interior covered by the upper oil pan side wall portion. The sound insulation structure for an automobile engine according to claim 2.

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