KR940004355B1 - Block structure of engine - Google Patents

Abstract

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Description

Block structure of the engine

1 is a partial cross-sectional view of the lower half of the engine body in cross section.

2 is a plan view of the lower block viewed from above.

3 is a cross-sectional view taken along the line III-III of FIG.

4 is a cross-sectional view taken along the line IV-IV of FIG.

5 is a bottom view of the lower block viewed from below.

6 is a side view of the lower block viewed from the side.

7 is a sectional view taken along the line VII-VII of FIG.

* Explanation of symbols for main parts of the drawings

1: engine body 2: cylinder block body

4: crankshaft 5: crank seal

6: Lower block 6e: Side wall of the lower block

7: oil pan 8: common bolt

9-12: Partition Wall

18: Bolting hole formed in the partition wall

19: bolt 20: bearing cap

20a: Boss part installed at the side of bearing cap

21: horizontal through hole formed in the side wall of the lower block

22: Slide Bush 23: Bolt

30: thin plate portion formed on the side wall of the lower block

31: pillar portion formed on the side wall of the lower block

The present invention relates to an improvement of the block structure of an engine.

Regarding the block structure of the engine, in Japanese Laid-Open Patent Publication No. 62-108612, the edge of the cylinder block and the side of the bearing cap for supporting the crankshaft accommodated in the edge portion are fixed with a bowl to support the crank. A technique for increasing rigidity is disclosed.

The publication also discloses connecting the lower end surface of each bearing cap to a beam of a separate member.

By the way, the main purpose of lightening the engine is to shorten the length dimension of the edge part so as to be called the short edge, and to fasten the lower block made of aluminum to the lower end of the cylinder block body, It is known to form a crank seal.

However, the lower block is conventionally attached to a position as a member supporting the transmission, and thus, the present situation is that the technical development is under consideration only from the standpoint of securing rigidity against power unit vibration.

SUMMARY OF THE INVENTION An object of the present invention is to provide a block structure of an engine in which an engine having a lower block as a whole is used to improve support of a bearing cap by using the lower block.

In order to achieve the above technical problem, in the present invention, a partition wall is formed in the lower block to extend between both side walls of the lower block, and to block the inner space of the lower block back and forth, and to the partition wall. The lower part of the bearing cap which supports the said crankshaft is fixed, and the one side fixed the side part of a bearing cap to the side wall of a lower block.

EMBODIMENT OF THE INVENTION Below, the Example of this invention is described based on drawing.

In FIG. 1, 1 is an engine main body, the engine main body 1 becomes a 4-cycle reciprocating 4-cylinder engine, and the piston (not shown) slips in the inner diameter 2a of the cylinder block main body 2. In FIG. The piston moves freely, so that the reciprocating motion of the piston is transmitted to the crankshaft 4 via the connecting rod 3 and converted into rotational motion.

The cylinder block body 2 is made of cast iron, and the edge portion 2b forming the crank seal 5 is a so-called short edge, so that the height position of the lower end of the edge portion 2b is approximately the crank shaft ( It is at the height position of the rotation center 4a of 4).

The lower block 6 is provided at the lower end of the edge portion 2b, and cooperates with these edge portions 2b and the lower block 6 to form a substantial crank seal 5, and the lower block 6 The oil pan 7 is installed at the lower end of the bottom, so that the lower block 6 and the oil pan 7 are fastened together by the bolt 8.

That is, the bolt 8 is inserted from the oil pan 7 side, penetrates the lower block 6, and is fixed to the cylinder block body 2 (lower end flange).

The size of the oil pan 7 will be described later.

The lower block 6 will be described in detail with reference to the drawings below in FIG. 2.

In this embodiment, the lower block 6 is made of aluminum (A1), and its weight is reduced.

The rear end portion 6a of the lower block 6 expands gradually downward and sideways as it goes rearward, and a transmission (not shown) is attached to the rear end surface 6b.

As shown in FIG. 2, the inner space of the lower block 6 is provided in four partition walls 9 and 12 provided with a gap from the front side to the rear side (from the right side to the left side in FIG. 2). Divided by the first partition wall (9) becomes the crank space (NO. 1) for the first cylinder, and between the second partition wall (10) and the third partition wall (11) It becomes the crank space NO.2 for a cylinder, and the crank space NO.3 for a 3rd cylinder becomes between the 3rd partition wall 11 and the 4th partition wall 12, Between the partition wall 12 and the rear end wall 6C of the lower block 6 is the crank space NO. 4 (cylinder of FIG. 2) for cylinder # 4.

The partition walls 9 and 12 are connected by the partition wall plate part 13, and the front end wall 6d of the first partition wall 9 and the lower block 6 is further connected. Between the fourth partition wall 14 and the rear end wall 6C of the lower block 6 is connected by the bottom plate portion 6f of the lower block 6 therebetween. Therefore, these elements 13, 14 and the like are suppressed from being widened or reduced between the partition walls 9, 12.

In the partition portion 13 between the partition walls, as shown by reference numeral 13a in FIG. 2, an oil recovery hole is provided, and a crank for cylinder 1 and cylinder 3 through the oil recovery hole 13a. Oil in the spaces NO. 1-NO. 3 is refluxed to the oil pan 7.

In addition, an open portion 13b is formed in the plate 13, and the open portion 13b allows the crank spaces NO. 1 to NO. 3 and oil for the first and third cylinders. The space in the fan 7 is connected in series.

This open part 13b is provided on both parts of the lower block 6 (both parts of the plate 13), and is located in the crank spaces NO. 1-NO. 3 of the cylinders 1 and 3. Fog oil is also refluxed into the space in the oil pan 7 through the open portion 13b.

That is, the air in the crank space (NO. 1)-(NO. 3) is also extruded into the space in the oil pan (7) in accordance with the downward movement of the cylinder 1 and cylinder 3 piston, the movement of the air in this crank space At the same time, the misty oil in the crank spaces NO. 1-(NO. 3) of cylinders 1 and 3 is also refluxed into the space in the oil pan 7.

The oil stored in the oil pan 7 is sucked up by an oil pump (not shown), and the sucked oil is guided to each sliding part.

In Fig. 2, reference numeral 15 denotes an oil filter, and the oil purified in the oil filter 15 is also guided to the oil pump through the oil feed pipe 16.

The oil pan 7 has a length 3 in the longitudinal direction of the lower block 6 in relation to the transmission attachment portion formed on the rear end surface 6b of the lower block 6 (NO. 1). As shown in Fig. 5, the seat 6g for attaching the oil pan of the lower block 6 is located in front of the third partition wall 11 close to its rear end. It is.

The rear end of the lower block 6 (the above-expanded portion below and laterally) is a portion where the number 4 cylinder is located.

In the rear end walls 6C of the partition walls 9, 10, 12, and the lower block 6, except for the partition wall 11 of FIG. As shown in FIG. 5, a bolt insertion hole 18 extending in the vertical direction is formed, and the bolt insertion hole 18 is formed in each of the partition walls 9, 10, 12, and the lower block 6, respectively. Each of the rear end walls 6C has two spaced apart in the longitudinal direction.

The bolt 19 is inserted into the bolt insertion hole 18 at a lower side thereof, and the front end of the bolt 19 is screwed into a screw hole (not shown) which is opened at the bottom of the bearing cap 20. By the bolt 19, the lower block 6 and the bearing cap 20 in the inward direction than the bolt 20b which fastens the bearing portion 20 (not shown) of the bearing cap 20 and the cylinder block body 2 to each other. ) Is integrated.

Since the bearing cap 20 comprises a part (about lower half) of the bearing part of the crankshaft 4 as is well-known, this bearing cap 20 is usually cast iron.

Among the bearing caps 20, the bearing caps 20 provided on the first partition wall 9, the third partition wall 11, and the rear end wall 6C of the lower block 6 have a side portion thereof. It is integrated with the lower block 6.

That is, the first partition wall 9, the third partition wall 11, and the rear end wall 6C are opened on the side wall 6e of the lower block 6, as shown in FIG. A horizontal through hole 21 extending in the right direction is formed, and the slide bush 22 is fitted into the horizontal through hole 21.

On the other hand, the bearing cap 20 provided in the bearing cap 20 (the 1st, 3rd partition walls 9 and 11 and the rear end wall 6C of the lower block 6) protrudes outward to the side part. The boss part 20a is provided, and the screw hole (not shown) is formed in this boss part 20a.

Then, the front end of the bolt 23 inserted into the slide bush 22 is screwed into a screw hole formed in the boss portion 20a, whereby the side wall 6e of the lower block 6 and the bearing cap The side part of (20) is integrated.

That is, the bearing cap 20 provided corresponding to the first and third partition walls 9 and 11 and the rear end wall 6C has its side portion integrated with the lower block 6 ( The bearing cap 20 provided in the partition wall 9 and the rear end wall 6C of 1 is also integrated in the lower block 6 in its lower part.

In the bearing cap 20A provided corresponding to the second and fourth partition walls 10 and 12, as shown in FIG. 4, the boss portion 20a is not formed at the side portion thereof. Only the lower part is integrated with respect to the lower block 6.

With the above structure, since the bearing cap 20 is fixed to the lower block 6, the support rigidity of the bearing cap 20 can be improved, without using the beam made of a separate member like conventionally.

In particular, in the bearing cap 20 with the boss, the side portion thereof is fixed to the lower block 6 and is fitted laterally by the lower block 6, so that the occurrence of cracking of the bearing cap 20 is prevented. It can be prevented.

In particular, the bearing cap 20 provided in the 1st partition wall 9 and the rear end wall 6C is integrated also in the lower part with respect to the lower block 6, and is inserted in the lower part by this lower block 6, too. Therefore, the occurrence of cracking of the bearing cap 20 can be prevented more effectively.

In addition, since the slide bush 22 is interposed with respect to the side part fixing of the bearing cap 20, the slide bush 22 can absorb the dimensional error of the bearing cap 20, etc. It does not impair workability when assembling the engine.

A space 25 (hereinafter referred to as a boss attachment space, see FIG. 3) formed between the boss bearing bearing cap 20 and the partition wall 9, the boss bearing bearing 20A and the partition wall Comparing the spaces 26 (hereinafter referred to as bossless spaces, see FIG. 4) formed between (10) and the like, at least the boss portion 20a does not exist in the bossless spaces 26. As a result, it is larger than the boss attachment space 25.

The difference between the size of the boss attachment space 25 and the bossless space 26 means the following.

As described above, the second partition wall 10 provided with the bossless bearing cap 20A has a crank space NO.1 for the first cylinder and a crank space NO.2 for the second cylinder. The space 26 is partitioned between the gaps, so that the bossless space 26 constitutes a portion communicating with the spaces with these crank spaces NO. 1 and NO.

Similarly, the bossless space 26 of the fourth partition wall 12 is connected between the crank space NO.3 for the third cylinder and the crank space NO.4 for the fourth cylinder in series. Part.

On the other hand, the boss attachment space 25 of the third partition wall 11 communicates between the crank space NO. 2 for the second cylinder and the crank space NO. 3 for the third cylinder in series. Is part of the NO. 2-NO. The portion 25 that passes through 3 is the NO. 1-NO. 2 and NO. 3-NO. The passage effective area is smaller than that of the portion 26 which is connected in series.

By the way, when the ignition order is represented by the cylinder number, the engine main body 1 has NO. 1 (cylinder 1) -NO. 3 (cylinder 3) -NO. 4 (cylinder 4) -NO. 2 (cylinder 2).

For this reason, the piston of cylinder 1 (NO. 1) and the piston of cylinder 4 operate in the same direction (for example, ascending), and the piston of cylinder 2 (NO. 2) and cylinder 3 (NO. 3). Pistons in the same direction (for example, lowering) is performed.

In other words, cylinder 1 (no. 1) and cylinder 2 (no. 2) and cylinder 3 (no. 3) and number 4 with a bossless connecting part 26 having a large passage effective area in between. In cylinder NO. 4, the piston operates in the reverse direction.

On the other hand, in the second cylinder (NO. 2) and the third cylinder (NO. 3), the piston moves in the same direction with the portion 25 passing through the boss with a small passage effective area therebetween.

By the way, as an example, the air in the 2nd and 3rd crank spaces NO.2 and (NO.3) is part 26 through which the piston of the corresponding cylinder descend | falls, and has a large passage effective area, and it connects continuously. Through this, the air in cylinder 2 (NO. 2) (air of the piston's stroke) smoothly changes into space 1 (NO. 1) (the piston moves up), and space 3 (NO. 3). The air inside the) changes smoothly into space 4 (the piston moves up).

For this reason, the rising temperature or the lowering motion of the piston is not impeded by the air in the crank space, and the negative action (pumping loss) caused by the air in this crank space inhibits the operation of the piston can be reduced).

In particular, the crank space NO. 4 for cylinder No. 4 is divided by the bottom plate portion 6f of the lower block 6 as described above, so as to be in direct communication with the space in the oil pan 7. Since the open portion 13b is not connected to the oil pan 7 in the same manner as other crank spaces NO. 3 and the like, the crank space NO. 4 for the fourth cylinder is not provided. By passing through the large portion 26 is connected to the crank space (NO. 3) for the third cylinder, the pumping loss of the fourth cylinder (NO. 4) can be reduced.

6 shows the lower block 6 viewed from the side, and the side wall 6e of the lower block 6 has a thin plate portion 30, pillar portions 31 provided side by side at intervals, and ribs. It is formed of 32.

In the column portion 31, an insertion hole of the bolt 8 for fastening the lower block 6 and the cylinder block body 2 described above is formed.

In addition, the ribs 32 are provided in a transverse form to increase the torsional rigidity of the lower block 6.

In the thin plate portion 39, the portion 33 facing the crank space NO. 3 of the third cylinder and the portion 34 facing the crank space NO. 4 of the fourth cylinder include: The thin plate portion 30 is not provided.

That is, the said parts 33 and 34 are the open part opened to the side of the lower block 6. As shown in FIG.

The opening portions 33 and 34 are not to damage the intercommunication relationship between these portions 33 and 34, and are separate members from the lower block 6, for example, the plate member 35. Is covered by).

That is, the plate member 35 is fixed to the side wall 6e of the lower block 6 using a bolt (not shown).

The bolt is screwed into a screw hole (formed in the side wall 6e of the lower block 6) indicated by reference numeral 36 in FIG.

By the above structure, the crank space NO.3 of the 3rd cylinder and the crank space NO.4 of the 4th cylinder are the said plate member 35 through the said opening part 33,34. By passing through the passage formed on the side of the lower block 6, it is in communication with each other.

This makes it possible to further reduce the pumping loss of the fourth cylinder with respect to the fourth cylinder NO.

Such open portions 33, 34 and the plate member 35 may be provided only on one side wall 6e of the lower block 6, or both side portions 6e of the lower block 6, You may install in 6e.

In addition, the plate member 35 can also be used as a reinforcing member of the lower block 6 (improving the bending rigidity of the lower block 6).

Such a reinforcement function can be easily adjusted by changing the material or plate thickness of the plate member 35, or it is also possible to form and adjust the frame in the plate member 35.

A rear end portion 6a of the lower block 6 will be described with reference to FIGS. 5 and 7.

As described above, the rear end portion 6a of the lower block 6 extends laterally and downwardly from the fourth partition wall 12 toward the rear end 6b of the lower block 6. It is.

By the bulging shape in the rear end part 6a of this lower block 6, rigidity with respect to the power unit vibration of the lower block 6 (cylinder block 2) including a transmission is ensured.

In the rear end portion 6a of the lower block 6, a connection between the oil pan attachment seat portion 6g and the rear end wall 6C of the lower block 6 is connected to both side portions of the lower portion 6a. Several ribs 40 are formed.

In addition, the recessed part 41 which opens downward is formed in the center part fitted in the site | part (the said side part) in which these ribs 40 were formed, This recessed part 41 and the said rib 40 are formed, The side portion is partitioned by a second rib 42 extending between the oil pan seating surface 6g and the rear end wall 6C of the lower block 6.

In addition, the concave portions 41 allow the partition walls 12 to have different lengths of the bolt insertion holes 18 formed in the fourth partition wall 12 and the rear end wall 6C of the lower block 6. 11) is equal to the length of the bolt insertion hole 18 formed in the back.

Due to the above configuration in the rear end portion 6a of the lower block 6, first, the rear end wall 6C of the lower block 6 to which the transmission is attached by the ribs 40 and 41 is first mounted. The partition wall 12 is connected in a rigid relationship.

Therefore, by increasing the rigidity of the rear end wall 6C of the lower block 6 directly affected by the power transmission device, it is possible to suppress the vibration of the power unit or the generation of the vibration sound due to the vibration of the power unit.

Again, the length of the bolt insertion hole 18 formed in the fourth partition wall 12 and the rear end wall 6C of the lower block 6 is the bolt insertion hole formed in the other partition wall 11 or the like. Since it is the same as the length dimension of 18), the support rigidity of the bearing cap 20 provided in the 4th partition wall 12 and 6C of the rear end wall of the lower block 6 can be improved.

That is, when the lower portion of the bearing cap 20 is bolted without forming the concave portion 41, the bolt having a large shaft length such that the rear end portion 6a of the lower block 6 is swelled downward. It is necessary to use (19).

In contrast, in the present embodiment, the concave portion 41 is formed, whereby a bolt 19 having a short shaft length can be used, and the bearing cap 20 is shortened by the shortening of the bolt 19. Can increase the support stiffness.

As is clear from the above description, according to the present invention, since the lower and side portions of the bearing cap are fixed to the lower block, the support rigidity of the bearing cap can be improved.

And since the side part and the lower part of this bearing cap are pressed by the bearing cap which is the same member simultaneously, it becomes possible to prevent generation | occurrence | production of a tear of a bearing cap.

Claims (4)

The crank seal 5 is formed of the edge portion 2b of the cylinder block body 2 having the cylinder inner diameter 2a and the lower block 6 fastened to the lower end of the edge portion 2b. In the engine (1) in which the crankshaft (4) is provided in (5), the lower block (6) extends between the side walls (6e) and (6e) of the lower block (6) and the lower block thereof. Partition walls (9)-(12) are formed to partition the inner space of (6) back and forth, so that the lower portion of the bearing cap (20) supporting the crankshaft (4) on the partition walls (9)-(12). Is fixed, and a side portion of the bearing cap (20) is fixed to the side walls (6e), (6e) of the lower block (6). The side wall (6e), (6e) of the lower block (6) is formed with a through hole (21) extending laterally toward the side surface of the bearing cap (20). The bolt 23 is inserted into the slide bush 22 so that the side walls 6e and 6e of the lower block 6 and the side of the bearing cap 20 are inserted by the bolt 23. Block structure of the engine, characterized in that fixed. The side walls 6e and 6e of the lower block 6 have pillar portions 31 extending vertically, and the pillar portions 31 are arranged side by side at intervals. The portion 31 is formed into a thin plate portion 30, and a through hole 21 extending in the vertical direction is formed in the pillar portion 31, and the common bolt 23 inserted into the through hole 31 is formed. ), A block structure of an engine in which three characters of the lower block (6), an oil pan (7) provided at the lower end of the lower block (6), and the cylinder block body (2) are fastened. The side walls 6e and 6e of the lower block 6 have pillar portions 31 extending vertically, the pillar portions 31 being arranged side by side in the interval and The column portion 31 is a thin plate portion 30, and a through hole 21 extending in the up and down direction is formed in the pillar portion 31, and the common bolt inserted into the through hole 31 is formed. (3), the lower block 6, an oil pan 7 provided at the lower end of the lower block 6, and the cylinder block body 2 are fastened to each other. Block structure.