CN1573161A - Mounting structure of balancer casing for engine - Google Patents

Abstract

Provided is mounting structure of a balancer housing in an engine capable of attaining sufficient supporting rigidity of a crank shaft and securely decreasing engine noise by avoiding increase of a manufacturing cost due to structure complication and demerits due to the weight increase of the engine. A housing body 12 of the balancer housing 11 is disposed by offsetting it to the right interposing the crank shaft 4. The right side of the housing body 12 is fastened to the right side of a cylinder block 2, and the left side of the housing body 12 is fastened to respective bearing caps 5. The left side of a baffle plate 13 extended from the housing body 12 toward the left side is fastened to the left side of the cylinder block 2.

Description

Mounting structure of balancer case for engine

technical field

The present invention relates to a mounting structure of a balancer housing for an engine, and more particularly, to a mounting structure in which a balancer housing pivotally supporting a balancer shaft is mounted on a lower side of a cylinder block.

Background technique

In order to reduce the vibration of the engine during operation, the balancer shaft is rotationally driven synchronously with the rotation of the crankshaft to counteract the vibration force generated by the vertical movement of the piston and connecting rod. This type of balancer shaft is arranged on the underside of the cylinder block. In this case, the balancer shaft is pivotally supported in the balancer housing, and the support rigidity of the crankshaft is increased by fastening the balancer housing to the lower side of the cylinder block.

For example, in the mounting structure of the balancer housing disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 4-248041, the journal of the crankshaft is pivotally and detachably supported on the cylinder block of the engine by the bearing cap, and The balancer housing is fastened to the lower part of the bearing cap with bolts.

In addition, in the mounting structure of the balancer housing disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2000-65149, a base serving as a bearing cap pivotally supports the journal of the crankshaft, and the balancer housing is together Fastened to the lower part of the base.

However, according to the above mounting structure disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 4-248041, it is impossible to sufficiently increase the support rigidity of the crankshaft, and furthermore, it is impossible to reduce engine noise due to insufficient rigidity.

In addition, the above mounting structure disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2000-65149 has problems in that the production cost is increased due to the need to manufacture a base having a complicated shape, and in addition, the balancer housing is required to have Rigid structure, this is because it does not bring any help to improve the support rigidity of the crankshaft, and only uses the base to support the crankshaft, resulting in an increase in the weight of the engine.

Contents of the invention

Accordingly, an object of the present invention is to provide a mounting structure of a balancer housing for an engine in which a balancer housing pivotally supporting one balancer shaft is provided on the lower side of a cylinder block, and the balancer shaft Rotationally driven in synchronism with the rotation of the crankshaft, the journal of which is pivotally supported on the cylinder block by bearing caps, and the balancer housing is fastened on each lower portion of the bearing caps and on the lower portion of the cylinder block.

According to the above structure, the balancer shaft is rotationally driven synchronously with the rotation of the crankshaft while the balancer housing is located on the lower side of the cylinder block, which cancels the vibration generated by the vertical movement of the piston and connecting rod of each cylinder force.

In addition, the balancer housing is fastened on the lower portion of the bearing caps that support the respective journals of the crankshaft, and is also fastened on the lower portion of the cylinder block. Thus, the bearing caps are interconnected by the balancer housing and are prevented from bending (moving) relative to each other, and furthermore, the bearing caps are connected to the cylinder block by the balancer housing and are prevented from bending relative to the cylinder block. Therefore, it is possible to support the crankshaft with sufficient rigidity, and since it is not necessary to adopt an integrated bearing cap to ensure sufficient support rigidity, various disadvantages such as an increase in cost and weight that may occur if such a measure is adopted can be eliminated.

Description of drawings

The nature and other objects and advantages of the present invention will now be described with reference to the accompanying drawings, in which like reference numerals designate like or similar parts, in which:

FIG. 1 is a sectional view of an engine to which a mounting structure of a balancer housing according to an embodiment of the present invention is applied;

Fig. 2 is a side sectional view showing the engine in Fig. 1;

Figure 3 is a bottom view showing the engine in Figure 1;

Figure 4 is a bottom view showing the balancer housing in a manner corresponding to Figure 3; and

Fig. 5 is a perspective view showing a balancer case seen from a front diagonal direction.

Detailed ways

A preferred embodiment of a mounting structure of a balancer housing for an engine according to the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1 , the engine 1 is a three-cylinder in-line gasoline engine, and is set in a vehicle in a state inclined to the left as viewed from the front of the engine 1 . In FIGS. 2 and 3 , the cylinder block 3 from the right hand side is formed in order of #1, #2, and #3, and a gearbox (not shown) is connected to the left side (rear side) of the cylinder block 2 . Bearing holding portions 2 a having a semicircular cross section are formed in the cylinder block 2 at four positions in the direction in which the cylinders 3 are lined up. In the direction in which the cylinders 3 line up, the crankshaft 4 (only one end thereof is shown in FIG. 2 ) is arranged in a manner corresponding to the bearing holding portion 2 a.

The bearing holding part 2 a of the cylinder block 2 is provided with a corresponding bearing cover 5 , and the bearing cover 5 is fastened on the cylinder block 2 by bolts 6 . The bearing holding portion 5a, which is semicircular in cross section and formed at the corresponding bearing cover 5, corresponds to the bearing housing 2a of the cylinder block 2, and is pivotally supported by a crankshaft bearing (not shown) installed in its inner circumference. The journal 4a of the crankshaft 4 (as shown in FIG. 1 ).

The oil pan 7 is fastened on the lower side of the cylinder block 2 by bolts (not shown) to close the lower side of the cylinder block 2 . In the oil pan 7, screw holes 8 are formed at two positions on each of the right and left sides on the lower surface of the cylinder block 2, while a female screw boss 9 and a supply side protrusion A stage 10 is provided adjacently on the lower surface of each bearing cap 5 in a protruding form.

The balancer housing 11 is fastened on the underside of the cylinder block 2 in the oil pan 7 through the screw holes 8 and the screw holes 9 a formed in the respective female screw bosses 9 .

The structure and installation state of the balancer housing 11 will be described in detail below.

The balancer housing 11 is constructed in one piece by aluminum die-casting. As shown in FIG. 1 , on the underside of the cylinder block 2 , the housing body 12 of the balancer housing 11 is arranged in a manner offset to the right across the crankshaft 4 (that is, on the opposite side of the inclined side of the engine 1 ). above), and the baffle 13 extends entirely leftward from the left side of the housing body 12 (on the opposite side across the offset side of the crankshaft 4).

As shown in FIGS. 1 and 5 , the casing body 12 has a semicircular convex shape on its upper side and a semicircular concave shape on its lower side, and is arranged to extend in the length direction of the engine 1 . Flanges 14 (supporting portions) are formed at two positions on the front and rear of the case body 12, the flanges 14 being provided with bearing holes 14a having a circular cross section. As shown in FIG. 2, the position of each flange 14 in its length direction substantially corresponds to the position of the bearing cap 5 on the front side of the #1 cylinder and the position of the bearing cap 5 between the #2 and #3 cylinders. Location. The bolt hole 15 passes through the case body 12 on its right side and at a position corresponding to the corresponding flange 14 in the length direction of the case body 12, so that as shown in FIG. The left side of the housing 11 is fastened to the threaded hole 8 on the right side of the cylinder block 2 .

On the left side of the case body 12, receiving-side bosses 16 are protrudingly provided on each of the flanges 14, and spacer bosses are protruded at positions corresponding to #1 along the length direction of the case body 12. and the #2 cylinder between the bearing cap 5 and the position of the bearing cap 5 on the rear side of the #3 cylinder. The upper surfaces 16 a and 17 a of the receiving side boss 16 and the spacer boss 17 abut on the lower surface 10 a of the female screw boss 9 and the supply side boss 10 . The bolt hole 18 passes through the receiving side boss 16 and the spacer boss 17, and the center of the balancer housing 11 is fastened to the threaded hole 9a of each bearing cap 5 with a bolt 18a. The above-mentioned baffle 13 is formed as a substantially flat plate having substantially the same length as the case body 12 . Bolt holes 19 pass through the left side of the baffle plate 13 at positions corresponding to the respective flanges 14 in the length direction of the baffle plate 13, and fasten the right side of the balancer housing 11 to the left side of the cylinder block 2 with bolts 19a. On the threaded hole 8 on.

As shown in FIG. 2, in the case body 12, a balancer shaft 20 provided with a plurality of counterweights 20a at eccentric positions is arranged parallel to the crankshaft 4, and is arranged at two positions in the length direction of the balancer shaft 20. The journal 20b of the balancer shaft 20 at is pivotally supported in a state of being installed in the corresponding bearing hole 14a of the flange 14 . The front end of the balancer shaft 20 protrudes forward from the flange 14 at the front side, and the driven gear 23 is fastened on the front end of the balancer shaft 20 by bolts 21 . The driven gear 23 meshes with the drive gear 22 fastened to the front end of the crankshaft 4 . The balancer shaft 20 is rotationally driven in opposite directions in synchronization with the rotation of the crankshaft 4 to counteract the vibration force generated by the vertical movement of the pistons and connecting rods of the respective cylinders.

As shown in FIG. 5 , the cover member 24 is integrally formed with the front side of the balancer case 11 so as to be located at the boundary between the case body 12 and the baffle 13 . The cover member 24 includes the driving gear 22 and protects the outer circumference of the driving gear 22 from affecting the oil pan 7 on the lower side to prevent the driving gear 22 from stirring the oil.

On the other hand, as shown in FIGS. 1 and 2, on one side of the cylinder block 2, a main oil passage for supplying engine oil is formed parallel to the crankshaft 4 so that oil from the oil pump (supply oil) is supplied while the engine 1 is rotating. oil source) (not shown) is supplied into the main oil gallery. The bearing holding portions 2a of the cylinder block 2 are respectively formed with upper oil grooves 26 along the semicircular periphery, and the upper oil grooves 26 communicate with the main oil passage 25 through an oil distribution passage (first oil passage) 27, and pass through the above-mentioned crankshaft bearing. The oil hole communicates with the journal 4a of the crankshaft 4 .

Therefore, the engine oil in the main oil passage 25 is supplied into the upper oil groove 26 through the corresponding oil distribution passage 27, and is further supplied to the journal 4a of the crankshaft 4 through the oil hole of the crankshaft bearing, so that the oil in the journal 4a and the crankshaft Lubrication is achieved between the bearings.

In addition, the bearing retaining portion 5a of the bearing cap 5 at the front of the #1 cylinder and the bearing retaining portion 5a of the bearing cap 5 between the #2 and #3 cylinders are formed with corresponding lower oil grooves 28 along the semicircular periphery . The lower oil groove 28 is continuous with the upper oil groove 26 of the cylinder block 2 to form an annular groove and surround the crankshaft bearing. One end of the oil supply passage 29 (second oil passage) is connected to one side of the corresponding lower oil groove 28 , while the other end of the oil supply passage 29 opens in the lower surface 10 a of the supply side boss 10 .

One end of the oil receiving passage 30 is opened in the upper surface 16a of the receiving side boss 16 in the housing 11 in a manner corresponding to the opening of the oil supply passage 29 in the supply side boss 10, and the oil receiving passage The other end of 30 is opened in the corresponding front and rear bearing holes 14 a of the balancer housing 11 . Therefore, oil from the main oil gallery 25 is fed into the upper oil sump 26 and used to lubricate the bearings of the crankshaft 4 as described above, while part of the oil is guided through the upper oil sump 26 and the lower oil sump 28 to the oil supply passage 29 and oil receiving A lubricating effect is achieved between the bearing hole 14 a of the balancer housing 11 and the journal 20 b of the balancer shaft 20 in the channel 30 .

It should be noted that a measure is taken to ensure that the junction of the oil supply passage 29 and the oil receiving passage 30 is sealed, although a detailed description thereof is omitted.

As described above, in the oil passage structure of the engine 1 according to the present embodiment, the oil from the main oil passage 25 is supplied to the bearing of the balancer shaft 20 through the bearing of the crankshaft 4, and therefore, the oil distribution passage 27 is satisfied. , The oil supply channel 29 and the oil receiving channel 30 are continuously formed, thereby greatly simplifying the structure of the oil channel.

The mounting structure of the balancer housing 11 in the engine 1 constructed as described above will be described below.

First, the balancer housing 11 is fastened on the lower portion of all the bearing caps 5 that separately support the respective journals 4 a of the crankshaft 4 , and the balancer housing 11 is also fastened on the lower portion of the cylinder block 2 . Therefore, the bearing caps 5 are interconnected through the balancer housing 11 to prevent them from bending (moving) relative to each other. In addition, the bearing caps 5 are also connected to the cylinder block 2 through the balancer housing 11 to prevent the bearing caps 5 from moving relative to the cylinder. Body 2 is curved. This achieves sufficient support rigidity of the crankshaft 4 and effectively reduces engine noise due to insufficient rigidity.

In addition, since the crankshaft 4 can be supported with the above-mentioned sufficient rigidity, it is not necessary to take measures to integrate the bearing cap 5 as disclosed in Japanese Laid-Open Patent Publication No. 2000-65149. Disadvantages such as an increase in manufacturing costs and engine weight that would otherwise occur if measures such as those described above are adopted can thus be eliminated.

In addition, the flange 14 of the balancer housing 11 has a high rigidity sufficient to support the balancer shaft 20, and particularly in this embodiment, the flange 14 is directly mounted in a manner substantially corresponding to the bearing cap 5 of the cylinder block 2. Tightening, thus due to the high rigidity of the flange 14, bending of the bearing cover 5 can be more effectively prevented.

In addition, the case body 12 of the balancer case 11 is shifted rightward from the crankshaft 4, the right side of the case body 12 is fastened to the right side of the cylinder block 2, and the left side of the case body 12 is fastened to the bearing cap 5. and the left side of the baffle plate 13 extending leftward from the housing body 12 is fastened on the left side of the cylinder block 2 . That is, the balancer housing 11 is fastened to the cylinder block 2 on both sides of the position where the bearing cap 5 is fastened, and therefore, the bending of the bearing cap 5 can be prevented more effectively.

In addition, as shown in FIG. 5, since the case body 12 is curved along the outer periphery of the balancer shaft, it has high rigidity. On the other hand, the boundary between the housing body 12 and the substantially flat baffle 13 is prone to bending, since its cross-section is bent at right angles, but is prevented by the presence of a cover element 24 integrally formed with the boundary. . Therefore, the overall rigidity of the balancer housing 11 can be greatly improved, which greatly contributes to preventing bending of the bearing cover 5 .

For the above reasons, the use of the balancer housing 11 can effectively prevent the bending of the bearing cover 5 and further improve the support rigidity of the crankshaft 4 .

In addition, the balancer housing 11 is divided into the crankshaft 4 side and the oil pan 7 side by the housing body 12 and the baffle 13, which prevents oil level variation in the oil pan 7 and prevents the crankshaft 4 from agitating the oil. In addition, since the housing body 12 is located below the balancer shaft 20 , the balancer shaft 20 and the crankshaft 4 are separated from the oil pan 7 , thereby preventing the balancer shaft 20 from agitating the engine oil. Therefore, various troubles due to changes in the oil level and churning of the oil can be avoided.

On the other hand, the case body 12 supporting the single balancer shaft 20 is narrow in the horizontal direction, so if the case body 12 is arranged in a manner offset to the right from the crankshaft 4, the right side of the case body 12 is close to the cylinder block. 2, and the other side of the housing body 12 is close to the lower part 2 of the bearing cover 5, so that the housing body 11 can be placed in a comfortable position.

In addition, since the cylinder block 2 is inclined leftward with respect to the horizontal surface of the oil accumulated in the oil pan 7, a dead space is formed on the right side of the oil pan 7, and the housing body 12 is disposed in the dead space.

For the above reasons, by effectively utilizing the space in the oil pan 7 to provide the case body 12 , an increase in the size of the engine 1 , especially an increase in the height of the engine 1 can be suppressed due to the installation of the balancer case 11 .

On the other hand, although the balancer housing 11 is fastened to each bearing cap 5 at one position, the balancer housing 11 is fastened to the cylinder block 2 on both sides of the position where the bearing caps 5 are fastened. Therefore, the bending of the bearing cap 5 can be effectively prevented. In addition, if the balancer housing 11 is fastened to each of the bearing caps 5 at the above-mentioned one position, the bolt fastening operation during assembly, for example, can be simplified.

It should be understood that the present invention is not limited to the above-mentioned embodiments, but various changes can be made in or based on the above-mentioned embodiments without departing from the spirit of the present invention. For example, although in the above-mentioned embodiment, the mounting structure of the balancer housing 11 is applied to the three-cylinder in-line gasoline engine 1, the present invention is not limited thereto, but the present invention can be applied to a diesel engine, and the number and arrangement of cylinders can be changed , as long as the engine 1 is constructed such that the balancer housing 11 supporting the balancer shaft 20 is mounted on the lower portion of the cylinder block 2 .

In addition, although in the above-described embodiment, the housing body 12 supporting the single balancer shaft 20 is arranged in a manner offset to the right from the crankshaft 4, and the baffle plate 13 is extended to the left, the number of balancer shafts 20 and the housing The position of the body 12 is not limited thereto, but for example, the case body 12 supporting the two balancer shafts 20 may be arranged on the right and left sides of the crankshaft 4, and the baffle 13 may be omitted.

In addition, although in the above-mentioned embodiment, the balancer case 11 is fastened on all the bearing caps 5, the present invention is not limited thereto, but it may also be constructed in such a form that the balancer case Body 11 is not fastened on the bearing cap 5 at the rear of the #3 cylinder in Fig. 2 .

In addition, although in the above-described embodiment, the balancer shaft 20 is rotationally driven by the driving gear 22 and the driven gear 23, the present invention is not limited thereto, but the balancer shaft 20 may also be rotationally driven by a chain drive.

Claims (10)

1. mounting structure that is used for the balace weight housing of motor, the balace weight housing (11) that is wherein supporting a balace weight axle (20) pivotally is arranged on the downside of cylinder block (2), and balace weight axle (20) is rotated driving in the mode with the rotational synchronization of bent axle (4), it is characterized in that

The axle journal (4a) of bent axle (4) is supported on the cylinder block (2) pivotally by bearing cap (5), and balace weight housing (11) is fastened on each bottom of bearing cap (5) and on the bottom of cylinder block (2).

2. the mounting structure that is used for the balace weight housing of motor as claimed in claim 1, it is characterized in that, balace weight axle (20) is a single shaft, the position of its any side in departing from bent axle (4) both sides is supported on the described balace weight housing (11), and a side of described balace weight housing (11) is fastened to the bottom of cylinder block (2), and the opposite side of described balace weight housing (11) is fastened to the bottom of bearing cap (5).

3. the mounting structure that is used for the balace weight housing of motor as claimed in claim 2, it is characterized in that, cylinder block (2) is provided with in the mode of any lopsidedness in described bent axle (4) both sides, and balace weight axle (20) with the relative lateral deviation of the inclined side of cylinder block (2) from a position be balanced device housing (11) and support.

4. the mounting structure that is used for the balace weight housing of motor as claimed in claim 2, it is characterized in that, described balace weight housing (11) comprising: be fastened on the shell body (12) on the bearing cap (5), it is used for holding balace weight axle (20) in a position of departing from from bent axle (4); And the baffle plate (13) that extends integratedly towards a described relative side that departs from side from shell body (12), an end of balace weight housing (11) is fastened on the bottom of cylinder block (2) in a described relative side that departs from side.

5. the mounting structure that is used for the balace weight housing of motor as claimed in claim 4 is characterized in that, described shell body (12) and baffle plate (13) be the whole lower surface of coating gas cylinder body (2) basically.

6. the mounting structure that is used for the balace weight housing of motor as claimed in claim 4, it is characterized in that, also comprise the cap member that is integrally formed in the boundary between shell body (12) and the baffle plate (13), described cap member covers the secondary part (23) that is used for described balace weight axle (20).

7. the mounting structure that is used for the balace weight housing of motor as claimed in claim 6 is characterized in that, described secondary part (23) comprises and the driven gear that is installed in actuation gear (22) engagement on the front end of bent axle (4).

8. the mounting structure that is used for the balace weight housing of motor as claimed in claim 1, it is characterized in that, described bent axle (4) comprises a plurality of axle journals (4a), and bearing cap (5) is located in a plurality of axle journals (4a) on corresponding one, and balace weight housing (11) is fastened to a position on the bottom of each bearing cap (5), and is fastened on the bottom of the cylinder block (2) on the both sides that are positioned at bent axle (4).

9. the mounting structure that is used for the balace weight housing of motor as claimed in claim 1 is characterized in that, also comprises:

With the mode that cooperates with bearing cap (5) support pivotally the axle journal (4a) of bent axle (4) the bearing retaining part (2a, 5a);

Be formed on bearing retaining part (2a, 5a) oil groove in (26);

Be formed on the pivot supporting part (14) of balance support device axle (20) of being used in the balace weight housing (11);

Be formed on the main oil gallery (25) in the cylinder block (2), machine oil is fed into main oil gallery (25) from oily supply source;

From the first oily passage (27) of main oil gallery (25) branch, be used for engine oil supplying to oil groove (26); And

The second oily passage (29) that connects oil groove (26) and supporting part (14).

10. the mounting structure that is used for the balace weight housing of motor as claimed in claim 9, it is characterized in that, balace weight axle (20) is arranged on the below of bent axle (4), and the first oily passage (27) links to each other with the top of oil groove (2a, 5a), and the second oily passage (29) links to each other with the bottom of oil groove (2a, 5a).

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