KR100570423B1 - mounting structure of balancer housing for engine - Google Patents

Abstract

In the attachment structure of the balancer housing in an engine, the housing main body 12 of the balancer housing 11 is arrange | positioned, offset to the right which inserted the crankshaft 4, and the right side of the housing main body 12 is the cylinder block 2 The left side of the baffle plate 13 extending from the housing main body 12 to the left side is fastened to the right side of the housing main body 12 to each bearing cap 5, and the cylinder block ( Fasten to the left side of 2). This avoids defects such as an increase in the manufacturing cost and an increase in the weight of the engine due to the complexity of the configuration, and attains sufficient support rigidity of the crankshaft, thereby reliably reducing the engine noise.

Engine, balancer, housing

Description

Mounting structure of balancer housing for engine

1 is a cross-sectional view showing an engine to which the attachment structure of the balancer housing of the embodiment is applied.

2 is a side cross-sectional view of the engine of FIG.

3 is a bottom view of the engine of FIG.

4 is a bottom view of the balancer housing corresponding to FIG. 3; FIG.

5 is a perspective view of the balancer housing viewed obliquely from the front;

Technical Field

The present invention relates to an attachment structure of a balancer housing in an engine, and more particularly, to an attachment structure for attaching a balancer housing to a lower side of a cylinder block to rotatably support a balancer shaft. will be.

Prior art

For the purpose of reducing the vibration of the engine during the operation, the balancer shaft is driven in rotation in synchronization with the rotation of the crank shaft, thereby suppressing the vibration force generated by the vertical movement of the piston or the connecting rod. Countermeasures have been taken to offset them. This type of balancer shaft may be disposed under the cylinder block. In this case, the balancer shaft is rotatably supported in the balancer housing, and the support rigidity of the crankshaft is improved by fastening the balancer housing to the lower side of the cylinder block by bolts.

For example, in the attachment structure of the balancer housing described in Japanese Patent Application Laid-Open No. 4-248041, each journal portion of the crankshaft is rotatably supported by bearing caps individually with respect to the cylinder block side of the engine. The balancer housing is bolted to the lower part of these bearing caps.

Moreover, in the attachment structure of the balancer housing of Unexamined-Japanese-Patent No. 2000-65149, each journal part of a crankshaft is rotatably supported by the lower block which has a function of a bearing cap, and the balancer is provided in the lower part of this lower block. The housing is bolted together.

In the attachment structure of the former balancer housing, only the suppression of the deflection between the bearing caps can be suppressed, so that sufficient support rigidity can not be improved for the crankshaft, and further, engine noise due to the lack of rigidity cannot be reduced. .

In addition, in the latter balancer housing structure, it is necessary to produce a lower block having a complicated shape, and thus the manufacturing cost is high, and the balancer housing does not contribute at all to the improvement of the support rigidity of the crankshaft. Because of supporting the shaft, a rigid structure is required, causing problems such as an increase in the weight of the engine.

In the engine which arrange | positions the balancer housing which supported the balancer shaft rotatably at the lower side of a cylinder block, and rotates and balances a balancer shaft by a crank shaft, each journal part of a crankshaft is bearing individually with respect to a cylinder block side. It is rotatably supported by a cap, and the balancer housing is fastened to the lower part of each bearing cap and the lower part of a cylinder block, respectively.

Therefore, the balancer housing is driven to rotate in synchronization with the balancer shaft by the crank shaft in a state disposed below the cylinder block, and cancels the vibration force generated by the vertical movement of the piston or the cone rod of each cylinder.

And the balancer housing is fastened to the lower part of the bearing cap which supports each journal part of a crankshaft individually, and is also fastened also to the lower part of a cylinder block. As a result, each bearing cap is not only interconnected through the balancer housing and suppressed mutual warpage (position displacement), but also connected to the cylinder block through the balancer housing, thereby suppressing warp against the cold block. For this reason, sufficient crankshaft support stiffness can be obtained, and measures for integrating each bearing cap are not necessary to secure the support stiffness. Therefore, demerit such as cost rise or weight increase due to this measure is required. Is avoided beforehand.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of the attachment structure of the balancer housing in the engine which embodied this invention is described.

As shown in FIG. 1, the engine 1 is comprised as a three-cylinder gasoline engine in series, and is mounted in the vehicle in the inclined state to the left as viewed from the front of the engine. The cylinder block 2 is formed in the cylinder block 2 in the order of each cylinder of # 1, # 2, # 3 from the right side of FIG. 2, 3, and the transmission (not shown) on the left side (rear) of the cylinder block 2 is shown. Is connected. In the cylinder block 2, bearing support parts 2a having a semicircular cross section are formed at four locations along the alignment direction of the cylinder 3. The crankshaft 4 (only the front end is shown in FIG. 2) is arrange | positioned along the direction of alignment of the cylinder 3 so that it may correspond with these bearing holding parts 2a.

Bearing caps 5 are disposed in each bearing support portion 2a of the cylinder block 2, and each bearing cap 5 is fixed to the cylinder block 2 by bolts 6. The bearing support part 5a of the semicircular cross section formed in these bearing caps 5 corresponds to the bearing support part 2a on the cylinder block 2 side, and the crankshaft ( The journal part 4a (shown in FIG. 1) of 4) is rotatably supported, respectively.

An oil pan is fixed to the lower side of the cylinder block 2 by a bolt (not shown), and the lower side of the cylinder block 2 is closed by the oil pan 7. In the oil pan 7, screw holes 8 are formed at the lower left and right sides of the cylinder block 2, while female screw bosses 9 are formed on the lower surface of each bearing cap 5, respectively. And a supply-side boss 10 protrude adjacent to each other.

The balancer housing 11 is fixed to the lower side of the cylinder block 2 in the oil pan 7 using the screw hole 8 and the screw hole 9a formed in each female threaded boss 9.

Hereinafter, the configuration and attachment state of the balancer housing 11 will be described in detail.

The balancer housing 11 is integrally formed by aluminum die-casting. As shown in FIG. 1, the housing main body of the balancer housing 11 is offset to the right side (that is, the anti-inclined side of the engine 1) in which the crankshaft 4 is fitted to the lower side of the cylinder block 2. (12) is arrange | positioned, and the baffle plate 13 (baffle plate) extends integrally toward the left (opposite offset side which fitted the crankshaft 4) from the left side of this housing main body 12, have.

As shown in Figs. 1 and 5, the housing main body 12 (housing body) is arranged so as to have a convex shape downward and a concave shape upward, and extend in the front-rear direction of the engine 1. Bearing ribs 14 (bearing ribs) provided with bearing holes 14a having a circular cross section are formed at two front and rear positions in the housing main body 12. As shown in FIG. 2, the front and rear positions of these bearing ribs 14 are defined by the bearing cap 5 on the front side of the # 1 cylinder and the bearing cap 5 between the # 2 cylinder and the # 3 cylinder. Corresponds roughly with the front and back position. On the right side of the housing main body 12, bolt holes 15 penetrate up and down at the front and rear positions corresponding to the respective bearing ribs 14, respectively, and the balancer housing 11 through these bolt holes 15. ) Is fastened to the screw hole 8 on the right side of the cylinder block 2 by bolts 15a (shown in FIG. 1).

On the left side of the housing main body 12, the receiving side bosses 16 protrude on the respective bearing ribs 14, and the bearing cap 5 between the # 1 cylinder and the # 2 cylinder. The spacer boss 17 protrudes at the front-back position corresponding to the bearing cap 5 of the rear side of the cylinder and # 3 cylinder. The upper surfaces 16a and 17a of the receiving boss 16 and the spacer boss 17 abut against the lower thread 10a of the female thread boss 9 and the supply boss 10. Each of the receiving side boss 16 and the spacer boss 17 penetrates the bolt holes 18 up and down, respectively, and through the bolt holes 18, the center of the balancer housing 11 is formed by the bolts 18a. It is fastened to the screw hole 9a of the bearing cap 5. The baffle plate 13 has a substantially flat plate shape having a front and rear length substantially equal to that of the housing main body 12, and a bolt hole (for each of the front and rear positions corresponding to each bearing rib 14 on the left side of the baffle plate 13). 19 penetrates up and down, and the right side of the balancer housing 11 is fastened to the screw hole 8 on the left side of the cylinder block 2 via these bolt holes 19 by the bolt 19a.

As shown in FIG. 2, in the housing main body 12, a balancer shaft 20 having a plurality of weights 20a at an eccentric position is disposed in parallel with the crank shaft 4, and the balancer shaft 20 is disposed. The front and back two journal parts 20b are rotatably supported by being inserted in the bearing hole 14a of each bearing rib 14, respectively. The front end of the balancer shaft 20 protrudes forward from the bearing rib 14 on the front side, and the driven gear 23 is mounted by the bolt 21, and the driven gear 23 is placed at the front end of the crank shaft 4. Meshes with the mounted drive gear 22. In synchronization with the rotation of the crankshaft 4, the balancer shaft 20 is driven to rotate in the reverse direction, thereby canceling the vibration force generated by the vertical movement of the piston and the cone rod in each cylinder.

As shown in FIG. 5, the cover member 24 is integrally formed on the front side of the balancer housing 11 so as to be located at the boundary between the housing main body 12 and the baffle plate 13. The cover member 24 contains the driving gear 22 and hides the outer circumference of the driving gear 22 from the oil pan 7 side below, and the oil by the driving gear 22. It is intended to prevent the stirring.

On the other hand, as shown in Figs. 1 and 2, on one side of the cylinder block 2, a main oil 25 for oil supply is formed in parallel with the crank shaft 4, and the engine 1 During operation, oil from an oil pump (oil supplying source) (not shown) is supplied into the main gallery 25. An upper oil groove 26 is formed in each bearing support 2a of the cylinder block 2 along a semicircular inner circumference, and an oil distribution passage 27 in each upper oil groove 26 is formed. Respectively communicate with the main gallery 25 via a first oil passage, while communicating with the journal portion 4a of the crankshaft 4 via an oil hole of the crank bearing.

Therefore, the oil in the main gallery 25 is supplied into each upper oil groove 26 via each oil distribution passage 27, and the journal portion 4a of the crank shaft 4 via the oil hole of the crank bearing. And a lubricating action between the journal portion 4a and the crank bearing.

In addition, in the bearing cap 5 of the front side of the # 1 cylinder, and the bearing support 5a of the bearing cap 5 between the # 2 and # 3 cylinders, the lower oil groove 28 is formed along the semicircular inner circumference. Is formed. These lower oil grooves 28 form a ring shape continuously with the upper oil groove 26 on the cylinder block 2 side, and surround the crank bearing circumference. One end of each oil supply path 29 (second oil passage) is connected to one side of each lower oil groove 28, and the other end of the oil supply path 29 is connected to the bottom surface 10a of the supply side boss 10. It is open.

One end of the oil receiving passage 30 is provided on the upper surface 16a of the receiving boss 16 on the balancer housing 11 side so as to correspond to the opening of the oil supply passage 29 of the supply side boss 10. This opening is made, and the other end of each oil receiving passage 30 is opened into the bearing hole 14a before and after the balancer housing 11, respectively. Thus, as described above, oil from the main gallery 25 is supplied into the upper oil groove 26 and used for lubrication of the bearing portion of the crankshaft 4, while a part of the oil is from within the upper oil groove 26. After being guided to the oil supply passageway 29 and the oil receiving passageway 30 through the lower oil groove 28, the bearing hole 14a of the balancer housing 11 and the journal portion 20b of the balancer shaft 20. Lubricates with).

In addition, although the detail is not demonstrated, the countermeasure for ensuring seal property is implemented in the engagement part of the oil supply passageway 29 and the oil receiving passageway 30.

Thus, in the oil passage structure of the engine 1 of this embodiment, since oil from the main gallery 25 is supplied to the bearing part of the balancer shaft 14 through the bearing part of the crankshaft 4, It is only necessary to form the oil distribution passage 27, the oil supply passage 29, and the oil receiving passage 30 in series, so that the structure of the oil passage is considerably simplified.

Next, the effect | action of the attachment structure of the balancer housing 11 in the engine 1 comprised as mentioned above is demonstrated.

First, the balancer housing 11 is fastened to the lower part of all the bearing caps 5 which individually support each journal part 4a of the crankshaft 4, and is also fastened to the lower part of the cylinder block 2, too. . As a result, each bearing cap 5 is connected to the cylinder block 2 through the balancer housing 11 as well as being interconnected through the balancer housing 11 and suppressing mutual warpage (position displacement). Since curvature with respect to (2) is also suppressed, sufficient support rigidity of the crankshaft 4 can be achieved and engine noise resulting from lack of rigidity can be reduced reliably.

In addition, since the support rigidity of the crankshaft 4 can fully be secured in this way, it is not necessary to implement the measures which integrate each bearing cap 5 like the technique of Unexamined-Japanese-Patent No. 2000-65149, for example. Therefore, demerits, such as an increase in the manufacturing cost and an increase in the weight of the engine when this countermeasure is implemented, can be avoided beforehand.

In addition, the bearing rib 14 of the balancer housing 11 has a high rigidity for supporting the balancer shaft 20. In this embodiment, the bearing rib 14 has a bearing cap on the cylinder block 2 side. Since it is fastened directly in correspondence with (5), the warpage of the bearing cap 5 can be suppressed more reliably by using the high rigidity of the bearing ribs 14.

Furthermore, the housing main body 12 of the balancer housing 11 is arrange | positioned by offset to the right which inserted the crankshaft 4, The right side of the housing main body 12 is fastened to the right side of the cylinder block 2, and the housing The left side of the main body 12 is fastened to the bearing cap 5, and the left side of the baffle plate 13 extending from the housing main body 12 to the left side is fastened to the left side of the cylinder block 2. That is, since the balancer housing 11 is fastened to the cylinder block 2 side by the both sides of the location where the bearing cap 5 was fastened, the curvature of the bearing cap 5 can be suppressed efficiently.

In addition, as shown in FIG. 5, the housing main body 12 has a shape that is curved along the outer circumference of the balancer shaft 20 and has high rigidity, while the housing main body 12 and the roughly flat baffle plate ( The boundary portion 13) is easily bent because it is a cross-sectional shape that is bent at almost right angles, but since the warpage is suppressed by the cover member 24 formed integrally with the boundary portion, the stiffness of the balancer housing 11 as a result is greatly reduced. This greatly contributes to the suppression of the warpage of the bearing cap 5.

Therefore, the deflection of the bearing cap 5 can be reliably suppressed using the balancer housing 11 by these factors, and therefore the support rigidity of the crankshaft 4 can be improved further.

In addition, since the balancer housing 11 partitions the crankshaft 4 side and the oil pan 7 side of the engine 1 by the housing main body 12 and the baffle plate 13, the oil pan 7 It also acts to suppress oil level fluctuations in the c) or to prevent agitation of oil by the crankshaft 4. In addition, since the housing main body 12 is located below the balancer shaft 20, in addition to the crank shaft 4, the balancer shaft 20 is also partitioned from the oil pan 7 side, and the balancer shaft 20 Stirring of oil can also be prevented. Thus, there is also an advantage that various troubles caused by oil level fluctuations or agitation of oil can be avoided.

On the other hand, since the housing main body 12 supporting the single balancer shaft 20 has a relatively narrow dimension in the left and right direction, when the housing main body 12 is disposed by offsetting to the right in which the crank shaft 4 is inserted as described above, The right side of the housing main body 12 is located near the lower right side of the lower part of the cylinder block 2, and the other side of the housing main body 12 is located near the lower part of the bearing cap 5, without difficulty. The housing main body 11 can be arrange | positioned.

In addition, a dead space is formed on the right side in the oil pan 7 because the cylinder block 2 inclines to the left side with respect to the horizontal oil level of the oil stored in the oil pan 7. The housing main body 12 is disposed.

Therefore, due to these factors, the housing main body 12 can be arranged using the space in the oil pan 7 efficiently, and therefore, the enlargement of the engine 1 by the installation of the balancer housing 11, in particular, the engine height The increase of can be suppressed.

On the other hand, although the balancer housing 11 is fastened to each bearing cap 5 one by one, as described above, the balancer housing 11 is mounted on the cylinder block 2 side at both sides of the fastening portion of the bearing cap 5. In this case, the whip suppression action of the bearing cap 5 is sufficiently obtained. In addition, there is also an advantage that the bolt fixing operation and the like in the assembling process can be simplified by using one fastening as described above.

Although the description of the embodiment is completed as above, the aspect of the present invention is not limited to this embodiment. For example, in the said embodiment, although it embodied as the attachment structure of the balancer housing 11 in the inline 3-cylinder gasoline engine 1, the balancer housing 11 which supports the balancer shaft 20 is the cylinder block 2 If the engine is attached to the lower part of the engine, the type and type of the engine is not limited to this, but may be applied to, for example, a diesel engine, or the number of cylinders or the arrangement of cylinders may be changed.

Moreover, in the said embodiment, while supporting the single balancer shaft 20 in the housing main body 12, offset | positioning to the right side which fitted the crankshaft 4, and extending the baffle plate 13 toward the left side, The number of the balancer shafts 20 and the arrangement state of the housing body 12 are not limited to this, but for example, the housing body supporting the two balancer shafts 20 after the baffle plate 13 is closed. You may arrange | position 12 over the left and right both sides of the crankshaft 4.

In addition, in the said embodiment, although the balancer housing 11 was fastened to all the bearing caps 5, it is not necessary to necessarily fasten all the bearing caps 5, For example, of the # 3 cylinder shown in FIG. You may comprise so that it may not fasten to the bearing cap 5 of a rear side.

In addition, in the said embodiment, although the balancer shaft 20 was rotationally driven using the drive gear 22 and the driven gear 23, the drive system is not limited to this, For example, you may change to a chain drive.

According to the present invention, since sufficient crankshaft support rigidity can be obtained, and measures for integrating each bearing cap are not required in order to secure support rigidity, demerits such as cost rise and weight increase due to these measures are eliminated. (demerit) is avoided beforehand.

Claims (10)

delete The engine 1 which arrange | positions the balancer housing 11 which supported the balancer shaft 20 rotatably under the cylinder block 2, and rotates and drives the said balancer shaft 20 synchronously with the crankshaft 4. In the attachment structure of the balancer housing in The journal portion 4a of the crankshaft 4 is rotatably supported with respect to the cylinder block 2 side by a bearing cap 5, and the balancer housing 11 is formed of each bearing cap 5. Fastened to a lower part and a lower part of the cylinder block 2, A single balancer shaft 20 is supported by the balancer housing 11 at a position offset to either side on which the crankshaft 4 is fitted, and one side of the balancer housing 11 is offset to the cylinder block. (2), and the other side of the balancer housing (11) is fastened to the lower portion of the bearing cap (5), the attachment structure of the balancer housing in the engine. The method of claim 2, The cylinder block 2 is disposed to be inclined to either side of the crank shaft 4 on both sides, the balancer shaft 20 is offset to the half inclined side of the cylinder block (2) the balancer housing ( 11) The attachment structure of the balancer housing in an engine characterized by the above-mentioned. The method of claim 2, The balancer housing 11 includes a housing main body 12 which receives the balancer shaft 20 at a position offset from the crankshaft 4 and is fastened to the bearing cap 5, and the housing main body 12. Attachment structure of the balancer housing in the engine, characterized by having a baffle plate 13 integrally extending toward the half offset side from the side and having an end end fastened to the lower portion of the cylinder block 2 on the half offset side. . The method of claim 4, wherein The housing body (12) and the baffle plate (13) cover almost the entire lower surface of the cylinder block (2), the attachment structure of the balancer housing in the engine. The method of claim 4, wherein A balancer in an engine comprising a cover member integrally formed at a boundary between the housing main body 12 and the baffle plate 13 while covering the driven portion 23 of the balancer shaft 20. Attachment structure of the housing. The method of claim 6, The driven part (23) is an attachment structure of a balancer housing in an engine, characterized in that the driven gear is engaged with each other with the drive gear (22) mounted at the front end of the crankshaft (4). The method of claim 2, The crankshaft 4 has a plurality of journal portions 4a, the bearing caps 5 are provided for the plurality of journal portions 4a, respectively, and the balancer housing 11 is each of the bearings. Attachment structure of balancer housing in engine characterized in that it is fastened to the lower part of the cap 5 one by one, and is fastened to the lower part of the cylinder block 2 located on both sides where the crankshaft 4 is fitted. . The method of claim 2, Bearing support parts 2a and 5a rotatably supporting respective journal parts 4a of the crankshaft 4 in cooperation with the bearing cap 5, and oil grooves formed in the bearing support parts 2a and 5a. 26, a bearing portion 14 formed in the balancer housing 11 and rotatably supporting the balancer shaft 20, and a main gallery formed in the cylinder block 2 and supplied with oil from an oil supply source. (25), a first oil passage (27) branching from the main gallery (25) to supply oil to the oil groove (26), and connecting the oil groove (26) and the bearing portion (14). The balance structure of the balancer housing in an engine further provided with the 2nd oil path (29). The method of claim 9, The balancer shaft 20 is disposed below the crankshaft 4, the first oil passage is connected to an upper portion of the bearing supports 2a and 5a, and the second oil passage 29 is the oil. An attachment structure of a balancer housing in an engine, which is connected to a lower portion of a groove.

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