JP7048191B2 - Internal combustion engine - Google Patents

Description

The present invention relates to an internal combustion engine and is characterized by an arrangement structure of an oil level gauge.

In an internal combustion engine, the amount of oil is detected by an oil level gauge inserted into an oil pan. Although the positions of the oil level gauges are different, Patent Documents 1 to 3 pay attention to the fact that a space for arranging a timing chain is formed between the front surface of the cylinder block and the cylinder head and the front cover. , It is disclosed that a level gauge guide groove is formed in a space (chain arrangement space) between a cylinder block and a cylinder head and a front cover.

Of these, looking at Patent Document 1, in the embodiment of FIG. 1, a chain guide is formed between the chain guide and the outer wall of the cylinder block and the cylinder head, and in the embodiment of FIG. 2, the chain guide and the cylinder are formed. Vertical ribs are formed between the block and the outer wall of the cylinder head, and a level gauge guide groove is formed between the ribs and the outer wall. Further, in the examples of FIGS. 3 and 4, a level gauge guide groove is formed in the chain guide itself.

In any case, in Cited Document 1, the level gauge guide groove is open toward the front cover side. The same applies to Patent Document 2. In Patent Document 3, the level gauge guide groove is formed in a space surrounded by the chain guide and the front cover, and the level gauge guide groove is closed by the front cover.

Japanese Unexamined Patent Publication No. 09-88539 Japanese Unexamined Patent Publication No. 10-02211 Japanese Unexamined Patent Publication No. 11-36840

In the configurations of FIGS. 1, 3 and 4 of Patent Document 1 and Patent Document 2, since the level gauge guide groove is open toward the front cover, the level gauge guide groove may get wet with oil. When the gauge is pulled out, the oil adhering to the level gauge guide groove may adhere to the oil level gauge, making it difficult to accurately detect the amount of oil.

In this regard, it can be said that if the level gauge guide groove is formed in a dedicated space separated by ribs as shown in FIG. 2 of Patent Document 1, oil can be prevented or significantly suppressed from entering the level gauge guide groove. In this case, since the width of the cylinder block and the cylinder head becomes large, another problem arises that the weight increases and the fuel consumption deteriorates.

On the other hand, in Cited Document 3, since the level gauge guide groove is a closed space, oil does not enter the level gauge guide groove, but there is a problem that the structure of the front cover is limited and therefore lacks generality. ..

The invention of the present application has been made to improve such a situation.

The invention of the present application is as described in claim 1.
"It includes a cylinder block, a cylinder head fixed to the upper surface thereof, and a front cover that covers the cylinder block and the front surface of the cylinder head.
A space is formed between the cylinder block, the cylinder head, and the front cover, which is guided by a chain guide and around which the timing chain rotates.
Further, a level gauge guide groove is formed between the front surface of the cylinder block and the cylinder head and the chain guide in a state of being separated from the oil drop passage located inside the level gauge guide groove . "
It is configured as. In the present invention, the front surface of the cylinder block and the cylinder head means the end surface on the side where the timing chain is arranged.

The invention of the present application also includes the configuration of claim 2, in claim 2 in claim 1.
"The level gauge guide groove and the oil drop passage are formed in a state of being partitioned by vertically elongated ribs so that the level gauge guide groove is located on the outside and the oil drop passage is located on the inside. ,
The ribs are tilted inward as they go down, and the oil pits are arranged closer to the ribs so that the oil flowing down from the oil pits is directed toward the ribs. "
It is configured as .

In the present invention, the level gauge guide groove is formed between the cylinder block and the cylinder head and the chain guide and is separated from the oil drop passage, so that the oil does not enter the level gauge guide groove. It can be stopped to improve visibility when detecting the amount of oil. In particular, if the entire level gauge guide groove is closed with a chain guide, the intrusion of oil can be blocked, so that the amount of oil can be detected quickly and accurately.

In addition, since the chain arrangement space that originally exists is effectively used and it is not necessary to widen the width of the cylinder block and the cylinder head, the size of the cylinder block and the cylinder head is not increased, and deterioration of fuel efficiency is prevented. can. Further, since the level gauge guide groove is not covered by the front cover, the structure of the front cover is not restricted. Therefore, the freedom in designing the front cover is high and the versatility is high.

In the configuration of claim 2, even if a plurality of ribs are not provided, the oil can flow down from the oil drop passage without diffusing due to the simple structure of only the main ribs.

It is a front view of the internal combustion engine which concerns on embodiment. It is a partially enlarged view of FIG. It is a front view of the state where the chain guide is separated and shown together. FIG. 6 is a sectional view taken along line IV-IV of FIG. (A) is a schematic plan view of the cylinder head, (B) is a sectional view taken along the line BB of (A), and is a sectional view taken along the line VB-VB of FIG. (A) is a sectional view taken along the line VIA-VIA in FIG. 3, (B1) is a sectional view taken along the line VIB-VIB in FIG. It is a cross-sectional view of VIB-VIB of. It is a plan sectional view which shows the other structural example of a level gauge guide groove.

(1). Outline of Internal Combustion Engine Next, an embodiment in which the present invention is embodied in an internal combustion engine for automobiles will be described with reference to the drawings. First, an outline of the internal combustion engine will be described. The basic configuration of the internal combustion engine is the same as that of the conventional engine, and as shown in FIG. 1, a cylinder block 1 and a cylinder head 2 fixed to the upper surface thereof are provided as basic elements of the engine body. A head cover 3 is fixed to the upper surface of the cylinder head 2, and an oil pan 4 is fixed to the lower surface of the cylinder block 1.

As shown in FIGS. 6 and 4, one front cover 5 overlaps the front surface of the cylinder head 2 and the cylinder block 1, and the front cover 5 is fixed to the cylinder block 1 and the cylinder head 2 with a large number of bolts. Has been done. The front end portion of the head cover 3 overlaps the upper end surface of the front cover 5 from above. Further, as shown in FIG. 4, the front portion of the oil pan 4 slightly protrudes in front of the cylinder block 1, and the front cover 5 overlaps the forward projecting portion of the oil pan 4 from above.

Outer walls (side walls) 6a, 6b, 7a, 7b are formed forward on the left and right sides of the cylinder block 1 and the cylinder head 2. In FIGS. 1 to 3, the front end faces of the outer walls 6a, 6b, 7a, and 7b are indicated by parallel diagonal lines. Therefore, the parallel diagonal lines of the cylinder block 1 and the cylinder head 2 are not a cross-sectional display. On the other hand, in FIG. 1, the left and right side portions of the oil pan 4 are indicated by parallel diagonal lines, which is an indication of a cross section.

Needless to say, a plurality of cylinder bores are formed in the cylinder block 1, and the crank shaft 8 is rotatably held by the bearing portion formed at the lower end portion of the cylinder block 1 via the crank cap 9. There is. As simply displayed in FIG. 4, the front end portion of the crank shaft 8 projects toward the front of the front cover 5, and the crank pulley 10 is fixed to the protruding front end portion. Reference numeral 10a in FIG. 4 indicates an auxiliary drive belt.

As is clearly shown in FIG. 1, the internal combustion engine of the present embodiment is a slant type in which the bore axis O is inclined by a slight angle θ (about 15 °) with respect to the vertical line V. To be precise, the exhaust side is inclined toward the lower side.

A driving sprocket 12 to which a timing chain 11 is engaged is fixed to a portion of the crank shaft 8 between the cylinder block 1 and the front cover 5. On the other hand, as partially shown in FIG. 5A, the intake camshaft 13 and the exhaust camshaft 14 are rotatably held on the upper surface of the cylinder head 2 via a camcap (not shown). The timing chain 11 meshes with the driven sprockets 15 and 16 fixed to the camshafts 13 and 14.

In the present embodiment, the intake camshaft 13 and the exhaust camshaft 14 are provided with VVT devices (variable valve timing devices) 17 and 18, and the VVT devices 17 and 18 bring the driven sprockets 15 and 16 into rotation phases. On the other hand, the rotation phases of the camshafts 13 and 14 are controlled to be advanced or retarded. Reference numeral 19 shown in FIGS. 1 and 2 is a flange provided at the front end of the cam shafts 13 and 14.

By providing the VVT devices 17 and 18, the driven sprockets 15 and 16 tend to be arranged at a position far from the front end of the cylinder head 2.

That is, the outer walls 6a, 6b, 7a, 7b are projected from the left and right side portions of the cylinder block 1 and the cylinder head 2, and therefore, as shown in FIG. 6, the front portions of the cylinder block 1 and the cylinder head 2 are provided with outer walls 6a, 6b, 7a, 7b. A forward-facing recess 20 sandwiched between the left and right outer walls 6a, 6b, 7a, 7b is formed, but the cylinder head 2 is provided with VVT devices 17 and 18, and the driven sprocket 15 and 16 are the front ends of the cylinder head 2. Since the timing chain 11 tends to be arranged at a position far from the front, the timing chain 11 is also arranged at a certain distance forward from the bottom surface of the forward facing recess 20.

That is, there is a certain distance E between the timing chain 11 and the bottom surface of the forward concave portion 20, but the size E of the gap is large due to the presence of the VVT devices 17 and 18. .. The VVT devices 17 and 18 may be provided on either the intake side or the exhaust side. The forward-facing recess 20 is formed with ribs for reinforcement and the like, bosses for attaching various members, and the like.

(2). Chain guide means As shown in FIG. 1, the peripheral circuit of the timing chain 11 has an outward path from the main sprocket 12 to the driven sprockets 15 and 16 and a return path from the driven sprockets 15 and 16 to the driven sprocket 12. are doing. In the relationship between the intake side surface and the exhaust side surface of the cylinder block 1 and the cylinder head 2, the outward path is located on the intake side and the return path is located on the exhaust side.

Then, in the forward concave portion 20 of the cylinder block 1 and the cylinder head 2, an outward route chain arm 22 and a timing chain 11 are provided as an example of a guide means for holding the timing chain 11 in a loosely bent state in front view on the outward route. An inbound chain guide 23 is arranged as an example of the inbound chain guide that is held in a loosely bent state in the front view on the inbound route, and the timing chain 11 is provided by the outbound chain arm 22 and the inbound chain guide 23. It is maintained in a posture that narrows the distance between the outward route and the return route. The outward chain arm 22 and the return chain guide 23 have substantially the same vertical length, and the heights of the upper end and the lower end are substantially the same.

The timing chain 11 is bent more on the outward route than on the return route. The outward chain arm 22 is movable and is connected to the forward concave portion 20 of the cylinder head 2 by a bolt 24 so that it can rotate about the upper end portion thereof. A hydraulic tensioner 25 is attached to the upper and lower parts of the outward chain arm 22, and the tensioner 25 pressurizes the outward chain arm 22 to hold the timing chain 11 in an appropriate tension state. ..

As shown in FIG. 6, the return chain guide 23 has a structure in which a guide piece 27 is projected forward on a substrate 26, and the guide piece 27 is provided with a slide portion 28 overlapping with a roller of a timing chain 11. The return chain guide 23 is a fixed type, and upper and lower overhanging portions 26a and 26b are provided at the upper end portion and the lower end portion of the substrate 26, and the overhanging portions 26a and 26b are provided with the boss 29a in the forward concave portion 20. , 29b are fixed with bolts 30.

In front view, the overhanging portion 26a of the substrate 26 is located on the left side of the guide piece 27, and the underhanging portion 26b of the substrate 26 is located on the right side of the guide piece 27. This is because the space for providing the bosses 29a and 29b is limited in relation to the bending mode of 27.

The upper half of the substrate 26 of the return chain guide 23 is provided with a left eaves portion 26c that overhangs (inwardly) on the left side of the guide piece 27 in a state of being integrated with the overhanging portion 26a. On the right side portion of the above, a right eaves portion 26d overhanging (outwardly) on the right side of the guide piece 27 is provided over the entire length in a state of being integrated with the underhanging portion 26b.

(3). Level gauge guide groove A level gauge guide groove 31 is formed in the forward concave portion 20 of the cylinder head 2 and the cylinder block 1 so as to open toward the right eaves portion 26d of the return chain guide 23.

Since the return path of the timing chain 11 passes near the right outer wall 6b of the cylinder head 2 in the forward-facing recess 20 of the cylinder head 2, the portion of the level gauge guide groove 31 where the cylinder head 2 is located is in the forward-facing recess 20. It is formed by the formed main rib 32 and the right outer wall 6b of the cylinder head 2. The main rib 32 extends to the upper end of the cylinder head 2.

On the other hand, in the forward concave portion 20 of the cylinder block 1, the return path of the timing chain 11 is widened downward from the right outer wall 7b of the cylinder block 1. Therefore, the portion of the cylinder head 2 in the level gauge guide groove 31 is formed by the main rib 32 formed in the forward-facing recess 20 and the auxiliary rib 33 located outside the main rib 32. The main rib 32 and the auxiliary rib 33 extend in parallel, and each extends to the lower end of the cylinder block 1. The auxiliary rib 33 is integrated with the lower boss 29b.

In FIG. 6, most of the level gauge guide groove 31 in the width direction is closed by the right eaves portion 26d of the return route chain guide 23, but as shown by the alternate long and short dash line in each segment of FIG. The level gauge guide groove 31 may be closed by the right eaves portion 26d over the entire width.

Further, there is a gap between the upper end of the return chain guide 23 and the upper end of the cylinder head 2, so that the upper end of the level gauge guide groove 31 remains open forward, but the return chain. The right eaves portion 26d of the guide 23 may be extended to the upper end of the cylinder head 2. Similarly, although there is a gap between the lower end of the return route chain guide 23 and the lower end of the cylinder block 1, the right eaves portion 26d of the return route chain guide 23 may be extended to the lower end of the cylinder block 1.

Although not explicitly shown in the head cover 3 shown in FIG. 1, an oil level gauge insertion hole communicating with the level gauge guide groove 31 is formed so as to penetrate vertically. The handle portion 34a of the oil level gauge 34 is fitted into the upper end portion of the oil level gauge insertion hole. The oil level gauge 34 is a simple blade type that only bends in one direction. That is, since the level gauge guide groove 31 is only loosely bent in front view so as to follow the shape of the return chain guide 23 of the timing chain 11, even if it is a simple blade type, the level gauge is bent and deformed. It can be inserted and removed from the guide groove 31.

A tube 35 for draining oil when changing oil can be inserted into the level gauge guide groove 31. In FIGS. 1 to 4, both the oil level gauge 34 and the tube 35 are displayed for convenience, but only one of them is actually used. In FIG. 6, (B) displays the tube 35, and (C) displays the oil level gauge 34.

(4). Summary / Other Embodiments There is a gap between the substrate 26 of the return chain guide 23 and the bottom surface of the forward-facing recess 20, but this embodiment uses the space of the forward-facing recess 20. Since the dead space is effectively utilized by forming the level gauge guide groove 31, the level gauge guide groove 31 can be formed without increasing the size of the cylinder head 2 and the cylinder block 1.

Further, since the corresponding portion of the level gauge guide groove 31 is closed by the right eaves portion 26d of the return route chain guide 23, the insertion passage of the oil level gauge 34 is accurately defined. Therefore, the oil level gauge 34 can be smoothly inserted without causing a phenomenon of being used in the middle.

Further, since a considerable range of the total length of the level gauge guide groove 31 is blocked by the right eaves portion 26d of the return route chain guide 23, the oil level is prevented from entering the level gauge guide groove 31. It is possible to prevent the gauge 34 from getting wet with oil. Therefore, the visibility of the wet state of the oil pan 4 is excellent, and the amount of oil can be quickly grasped.

FIG. 7 shows a variation of the level gauge guide groove 31. Of these, in the example shown in (A), in the case where the timing chain 11 is arranged close to the bottom surface of the forward-facing recess 20, the guide piece 27 is projected backward from the substrate 26, and the rib 32 is provided in the forward-facing recess 20. , 33 are provided to form the level gauge guide groove 31. Also in this case, the dead space of the forward facing recess 20 can be used to form the level gauge guide groove 31 without increasing the size of the cylinder head 2 and the cylinder block 1.

In the example shown in FIG. 7B, the level gauge guide groove 31 is formed by providing the ribs 32 and 33 in the return chain guide 23, and in the example shown in FIG. 7C, the cylinder block 1 is formed. The level gauge guide groove 31 is formed by providing the ribs 32 and 33 on the return route chain guide 23 and the return chain guide 23. Although the level gauge guide groove 31 of each embodiment is U-shaped, it may be formed in a U shape.

(5). Oil drop passage In this embodiment, the oil drop passage is formed by using the forward-facing recess 20 of the cylinder head 2 and the cylinder block 1. This point will be described next. FIG. 5A is a rough plan view of the cylinder head 2, and an intermediate bearing portion 37 for rotatably holding the camshafts 13 and 14 is formed inside the cylinder head 2 surrounded by a peripheral wall. The lubricated oil of the camshafts 13 and 14 flows down to the bottom surface of the upward recesses 38a, 38b, 38c ... partitioned by the intermediate bearing portion 37.

The oil that flowed down to the first upward recess 38a counting from the front flowed down from the horizontal hole type first oil pit 39 made in the front wall portion 2a of the cylinder head 2 and flowed down to the second upward recess 38b. The oil flows down from the vertically long second oil pit 40 toward the oil pan 4, and the oil that has flowed down into the third upward recess 38c flows down from the vertically long third oil pit 41 toward the oil pan 4. Oil pits corresponding to the upward recesses 38a, 38b, 38c ... Are provided.

The first oil pit 39 is formed in front of the head bolt insertion hole 42 located in the foreground. On the other hand, the other oil drop holes 40, 41 ... Penetrate the cylinder head 2 and the cylinder block 1, and are formed on the left and right outer sides of the bore space and inside the head bolt insertion hole 42. .. It is also possible to communicate a plurality of recesses and collect the oil flowing into the plurality of recesses in one oil pit.

As is clearly shown in FIGS. 1 to 3, the first oil pit 39 is opened at a portion hidden by the upper end portion of the return route chain guide 23 and at a portion slightly inward of the main rib 32. In FIGS. 1 to 3, the first oil pit 39 is shaded with a solid line, but this is a measure for clarifying the position. In reality, the first oil pit 39 is a return chain. It is located behind the guide 23 and cannot be seen (it should be displayed as a dotted line, but it is displayed as a solid shaded line to clarify the position).

The first oil pit 39 is merely penetrated through the front wall portion 2a of the cylinder head 2, but the bottom surface of the first upward recess 38a is located above the upper end of the return chain guide 23. If so, it may be formed in an L shape consisting of a vertical hole parallel to the cylinder bore axis and a horizontal hole parallel to the crank axis (or may be penetrated diagonally).

The main ribs 32 of the cylinder head 2 and the cylinder block 1 are slanted inward as they go downward, and in the present embodiment, they are slanted so as to fall toward the exhaust side. Therefore, the oil that has flowed down from the first oil pit 39 flows down toward the oil pan 4 along the main rib 32 without being scattered. Therefore, even if a plurality of ribs are not provided, the oil can flow down without being diffused by the simple structure of the main rib 32 (as shown by the alternate long and short dash line in FIG. 6A), inside the main rib 32. It is possible to provide another rib 43 in parallel.)

Further, since the left eaves portion 26c is formed in the upper half of the return route chain guide 23, even if the automobile shakes in the front-rear direction, the oil hardly gets on the timing chain 11, and the oil is on the timing chain. Scattering can be prevented or significantly suppressed by 11 laps.

The invention of the present application can be embodied in an internal combustion engine. Therefore, it can be used industrially.

1 Cylinder block 2 Cylinder head 3 Head cover 4 Oil pan 5 Front cover 6b, 7b Right outer wall 8 Crank shaft 11 Timing chain 12 Main driving sprocket 13, 14 Camshaft 15, 16 Driven sprocket 20 Forward recess 22 Forward chain arm 23 For return route Chain guide 26 Board 27 Guide piece 31 Level gauge guide groove 32 Main rib that constitutes the level gauge guide groove 33 Auxiliary rib that constitutes the level gauge guide groove 34 Oil level gauge 35 Oil change tube 39 1st oil drop hole

Claims (2)

It is provided with a cylinder block, a cylinder head fixed to the upper surface thereof, and a front cover that covers the cylinder block and the front surface of the cylinder head.
A space is formed between the cylinder block, the cylinder head, and the front cover, which is guided by a chain guide and around which the timing chain rotates.
Further, a level gauge guide groove is formed between the front surface of the cylinder block and the cylinder head and the chain guide in a state of being separated from the oil drop passage located inside the level gauge guide groove .
Internal combustion engine. The level gauge guide groove and the oil drop passage are formed in a state of being partitioned by vertically elongated ribs so that the level gauge guide groove is located on the outside and the oil drop passage is located on the inside.
The ribs are tilted inward as they go down, and oil pits are arranged closer to the ribs so that the oil flowing down from the oil pits is directed toward the ribs.
The internal combustion engine according to claim 1.

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