JP2018194140A - Balancer device - Google Patents

Abstract

A balancer device capable of improving the rigidity of an internal combustion engine is provided. A balancer device 20 includes balance shafts 21 and 22 and a balancer housing 23 on which the balance shafts 21 and 22 are rotatably provided. The balancer housing 23 includes an upper housing 231 and a lower housing 232. The upper housing 231 is attached to the lower side of the cylinder block, has a plate portion 231d that is arranged in a large part of the crank chamber as viewed in a plan view, and is arranged below the crankshaft. The plate portion 231d and the lower housing 232 are disposed adjacent to each other in the longitudinal direction of the upper housing 231. [Selection] Figure 3

Description

  The present invention relates to a balancer device for an internal combustion engine.

  Conventionally, a balancer device for reducing vibration of an internal combustion engine is known (see, for example, Patent Document 1).

  The balancer device of Patent Document 1 includes a pair of balance shafts arranged in parallel and a balancer housing in which the pair of balance shafts are rotatably provided. The balancer housing includes an upper housing and a lower housing, and a baffle plate is integrally formed in the upper housing. The balancer device is attached below the ladder frame and is housed inside the oil pan.

JP 2008-115919 A

  Here, in order to improve NV (noise vibration) performance, it is desired to improve the rigidity of the internal combustion engine.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a balancer device capable of improving the rigidity of an internal combustion engine.

  The balancer apparatus by this invention is provided with the balance shaft and the balancer housing in which the balance shaft was rotatably provided. The balancer housing includes an upper housing and a lower housing. The upper housing is attached to the lower side of the cylinder block, and has a plate portion that is disposed in a large part of the crank chamber as viewed in a plan view and that is disposed below the crankshaft. The plate portion and the lower housing are arranged adjacent to each other in the longitudinal direction of the upper housing.

  With this configuration, the upper housing is attached to the cylinder block, and the upper housing is disposed in a large part of the crank chamber, so that the balancer device can contribute to improving the rigidity of the internal combustion engine. Further, the rigidity of the balancer device itself can be improved by the plate portion.

  In the balancer device, the upper housing has an oil passage portion in which an oil passage is formed, and the oil passage portion is formed to extend in the longitudinal direction of the upper housing, and is one side of the upper housing in the short direction. May be arranged.

  If comprised in this way, since the rigidity of the balancer apparatus itself can be improved by an oil passage part, the rigidity of an internal combustion engine can be improved more.

  In this case, the oil passage of the oil passage portion may be configured such that oil discharged from the oil pump and directed to the oil filter flows.

  If comprised in this way, since high pressure oil is supplied from an oil pump to the oil path of an oil passage part, the rigidity of an oil passage part is made high.

  In the balancer device, the balance shaft includes a first balance shaft to which power is transmitted from the crankshaft, and a second balance shaft to which power is transmitted from the first balance shaft, and the first balance shaft is provided in the upper housing. A bearing member for rotatably supporting the first balance shaft is disposed on the other side of the short side direction and formed so as to be longer in the axial direction than the second balance shaft. It may be attached.

  If comprised in this way, since the rigidity of the balancer apparatus itself can be improved by the 1st balance shaft, the rigidity of an internal combustion engine can be improved more.

  According to the balancer device of the present invention, the rigidity of the internal combustion engine can be improved.

It is a figure for demonstrating an internal combustion engine provided with the balancer apparatus by one Embodiment of this invention. It is the schematic which looked at the inside of the crankcase of the internal combustion engine of FIG. 1 from the left side. It is the top view which showed the balancer apparatus provided in the internal combustion engine of FIG. It is the bottom view which showed the balancer apparatus of FIG. FIG. 3 is a diagram for explaining a planar arrangement position of a balancer device in a crank chamber of the internal combustion engine of FIG. 2.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

-Schematic configuration of internal combustion engine-
First, a schematic configuration of an internal combustion engine 100 including a balancer device 20 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  The internal combustion engine 100 is, for example, an in-line four-cylinder gasoline engine, and is a driving force source for traveling that is placed vertically on a vehicle (not shown). As shown in FIG. 1, the internal combustion engine 100 includes a cylinder block 1, a cylinder head 2, a crankcase 3, an oil pan 4, a head cover 5, and a chain cover 6 (see FIG. 2). . FIG. 1 shows only one of the four cylinders. In each figure, the X1 direction side is the front side, the X2 direction side is the rear side, the Y1 direction side is the right side, and the Y2 direction side is the left side.

  A cylinder head 2 is attached to the upper part of the cylinder block 1 and a crankcase 3 is attached to the lower part. A head cover 5 is attached to the upper part of the cylinder head 2. As shown in FIG. 2, an oil pan 4 is attached to the lower part of the rear side of the crankcase 3. A chain cover 6 is attached to the front side of the cylinder block 1, the cylinder head 2, and the crankcase 3. In FIG. 2, the crankshaft 8 to be described later and a bearing portion of the crankcase 3 that rotatably supports the crankshaft 8 are not illustrated in consideration of easy viewing.

  As shown in FIG. 1, the cylinder block 1 is formed with four cylinder bores 1a, and pistons 7 are provided in the cylinder bores 1a so as to be able to reciprocate. A crankshaft 8 is connected to the piston 7 via a connecting rod 7a. A combustion chamber 9 is formed between the piston 7 and the cylinder head 2, and an intake passage 10 and an exhaust passage 11 are connected to the combustion chamber 9.

  The cylinder head 2 is provided with an intake valve 12 that communicates or blocks the combustion chamber 9 and the intake passage 10, and an exhaust valve 13 that communicates or blocks the combustion chamber 9 and the exhaust passage 11. The intake valve 12 and the exhaust valve 13 are opened and closed by the rotation of the intake camshaft 14 and the exhaust camshaft 15 to which the rotation of the crankshaft 8 is transmitted via a timing chain (not shown). The intake camshaft 14 and the exhaust camshaft 15 are arranged in a cam chamber (space between the cylinder head 2 and the head cover 5) 16, and the timing chain is arranged in the chain cover 6 (see FIG. 2). Yes.

  In addition, an injector (fuel injection valve) 17 that injects fuel into the intake passage 10 is disposed in the cylinder head 2, and an ignition plug 18 is disposed so that the tip thereof faces the combustion chamber 9. The injector 17 is supplied with fuel from a fuel tank (not shown), and the fuel is injected from the injector 17 into the intake passage 10. This injected fuel is mixed with the intake air to form an air-fuel mixture and introduced into the combustion chamber 9. The air-fuel mixture introduced into the combustion chamber 9 is ignited by the spark plug 18 and combusted and exploded. The piston 7 is reciprocated by the combustion gas generated at this time, whereby the crankshaft 8 is rotated and the driving force (output torque) of the internal combustion engine 100 is obtained.

  Here, the crankshaft 8 is disposed in the crank chamber 19 and is rotatably supported by the cylinder block 1 and the crankcase 3. The crankshaft 8 includes a crankpin 8a to which a connecting rod 7a is connected, a balance weight 8b, and the like. Further, as shown in FIG. 2, the crankshaft 8 is provided with a crank pulley 8c around which an auxiliary machine belt (not shown) is wound, and a drive plate 8d on the rear side. The crank chamber 19 is provided with a balancer device 20 for reducing vibration of the internal combustion engine 100.

-Balancer device-
Next, the balancer apparatus 20 of this embodiment is demonstrated with reference to FIGS.

  As shown in FIG. 1, the balancer device 20 includes a pair of balance shafts 21 and 22 arranged in parallel, and a balancer housing 23 in which the balance shafts 21 and 22 are rotatably provided. The balancer device 20 is attached below the cylinder block 1 inside the crankcase 3. The balance shafts 21 and 22 are examples of the “first balance shaft” and the “second balance shaft” of the present invention, respectively.

  As shown in FIG. 4, the balancer housing 23 includes an upper housing 231, a lower housing 232, and a bearing member 233, and the lower housing 232 and the bearing member 233 are attached to the lower side of the upper housing 231. Specifically, the lower housing 232 is assembled to the upper housing 231 by a plurality of (six in this embodiment) bolts 234a. Further, the bearing member 233 is assembled to the upper housing 231 by a plurality of (two in this embodiment) bolts 234b. The bearing member 233 is disposed on the front side (one side in the longitudinal direction of the upper housing 231), and the lower housing 232 is disposed on the rear side (the other side in the longitudinal direction of the upper housing 231). A bearing portion (not shown) is provided between the bolts 234a adjacent to each other in the short side direction (Y direction) of the balancer housing 23, and a bearing portion (not shown) is provided between the bolts 234b of the balancer housing 23. It has been. For this reason, the balance shaft 21 is rotatably supported by the three bearing portions, and the balance shaft 22 (see FIG. 3) is rotatably supported by the two bearing portions.

  As shown in FIG. 3, the balance shafts 21 and 22 are formed so as to extend in the cylinder row direction (X direction), and are arranged in parallel with the crankshaft 8 (see FIG. 1). A plurality (two in this embodiment) of balance masses 211a and 211b are assembled to the balance shaft 21 so as to rotate integrally, and a plurality of (two in this embodiment) balance masses are mounted on the balance shaft 22. 221a and 221b are assembled so as to rotate integrally. The balance masses 211a, 211b, 221a, and 221b are formed in a substantially semi-cylindrical shape, and are provided in a state where the center of gravity is eccentric with respect to the center of rotation.

  The balance shaft 21 is formed to have a longer axial length than the balance shaft 22. The balance shaft 21 is disposed over the entire length of the upper housing 231 in the longitudinal direction (X direction) and protrudes to the front side of the upper housing 231. For this reason, one end (front end) of the balance shaft 21 is disposed in the chain cover 6 (see FIG. 2), and a sprocket (not shown) is attached. A chain (not shown) is wound around the sprocket, and the balance shaft 21 is connected to the crankshaft 8 through the chain. As a result, power is transmitted from the crankshaft 8 to the balance shaft 21, and the balance shaft 21 rotates at a rotational speed twice that of the crankshaft 8.

  Further, a driven gear 212 is attached to the balance shaft 21 so as to rotate integrally with the rear side of the balance mass 211b. A driven gear 222 is attached to the balance shaft 22 so as to rotate integrally, and the driven gear 222 is engaged with the driven gear 212. Accordingly, power is transmitted from the balance shaft 21 to the balance shaft 22, and the balance shaft 22 rotates in the reverse direction at the same rotational speed as the balance shaft 21.

  In such a balancer device 20, it is possible to suppress vertical vibration caused by the secondary inertia force of the internal combustion engine 100 by rotating the balance shafts 21 and 22 in the opposite directions by the rotational force of the crankshaft 8. .

  A pump driving gear 213 (see FIG. 4) is attached to the other end (rear end) of the balance shaft 21 so as to rotate integrally. Further, an oil pump 24 is assembled on the rear side of the balancer housing 23 as shown in FIG. The oil pump 24 is configured to be driven by a pump driving gear 213 (see FIG. 4) of the balance shaft 21. Here, an oil strainer 25 is provided in the oil pan 4, and an oil filter 26 is provided in the chain cover 6. Then, the oil stored in the oil pan 4 is pumped up by the oil pump 24 through the oil strainer 25, and the oil is pumped from the oil pump 24 to the oil filter 26. The oil filtered by the oil filter 26 is supplied to each part of the internal combustion engine 100, and each part is lubricated and cooled by the oil. The oil used for lubrication and cooling is returned to the oil pan 4.

  Here, as shown in FIG. 3, the upper housing 231 of the balancer device 20 is formed in a rectangular shape when seen in a plan view. The upper housing 231 includes mounting portions 231a and 231b, a column portion 231c, a plate portion 231d, and an oil passage portion 231e, which are integrally formed. Further, the upper housing 231 is formed with an opening 231f in which the balance masses 211a and 221a are disposed, and an opening 231g in which the balance masses 211b and 221b and the driven gears 212 and 222 are disposed.

  The attachment portions 231 a and 231 b are provided for attaching the lower housing 232. Balance shafts 21 and 22 are disposed between the mounting portions 231a and 231b and the lower housing 232 via bearings. The attachment portion 231a is disposed between the openings 231f and 231g in the longitudinal direction (X direction) of the upper housing 231 and is formed to extend in the short direction (Y direction) of the upper housing 231. The attachment portion 231b is disposed at the rear end portion (the end portion on the X2 direction side) of the upper housing 231 and is formed to extend in the short direction of the upper housing 231. A lower housing 232 is disposed below the mounting portions 231a and 231b and the openings 231f and 231g.

  The column portion 231c is provided to attach the upper housing 231 to the cylinder block 1 (see FIG. 1). The column portion 231c is formed to extend upward, and has a bolt insertion hole 231h into which a bolt 234c (see FIG. 2) is inserted. The upper housing 231 is attached to the cylinder block 1 by fastening the bolt 234 c inserted into the bolt insertion hole 231 h to the cylinder block 1. Therefore, as shown in FIG. 1, the upper housing 231 is provided so as to be suspended from the cylinder block 1 in the crank chamber 19, and the balance shafts 21 and 22 are disposed below the crankshaft 8. . As shown in FIG. 3, a plurality (six in this embodiment) of support columns 231 c are provided at intervals on the outer edge of the upper housing 231 as viewed in a plan view. Specifically, the column portions 231c are disposed at the four corners of the upper housing 231 and are disposed at both ends in the lateral direction in the middle portion in the longitudinal direction (position corresponding to the mounting portion 231a).

  The plate portion 231d is disposed below the crankshaft 8, and is configured so that the flow of oil that attempts to return to the oil pan 4 (see FIG. 2) is not hindered by the wind pressure caused by the rotation of the crankshaft 8. That is, the plate portion 231d is provided in order to suppress the wind pressure caused by the rotation of the crankshaft 8 from acting on the space below the plate portion 231d. As a result, the oil used for lubrication and cooling can easily return to the oil pan 4 along the bottom of the crankcase 3 (see FIG. 2).

  Specifically, the plate portion 231d is disposed on the front side with respect to the opening portion 231f. Therefore, as shown in FIG. 4, the plate portion 231d and the lower housing 232 are arranged so as to be adjacent in the longitudinal direction of the upper housing 231, and the plate portion 231d is arranged on one side (X1 direction side), The lower housing 232 is disposed on the other side (X2 direction side). The plate portion 231d is formed in an arc shape so that the central portion in the short direction of the upper housing 231 protrudes downward as compared with both end portions.

  Further, as shown in FIG. 3, the plate portion 231d is formed with a recessed portion 231i that is recessed downward, and an opening portion 231j is formed in the recessed portion 231i. The recess 231i is provided to avoid the plate portion 231d from interfering with the connecting rod 7a (see FIG. 1). The opening 231j is provided to avoid the recess 231i from interfering with the balance shaft 21.

  The oil passage portion 231e has an oil passage formed therein and is formed to extend in the longitudinal direction of the upper housing 231. The oil passage portion 231e is provided over the entire length of the upper housing 231 in the longitudinal direction, and is disposed on one side (Y1 direction side) of the upper housing 231 in the short direction. For this reason, the right end (Y1 direction side end) of the plate portion 231d is connected to the oil passage portion 231e. The balance shaft 21 is disposed on the other side (Y2 direction side) of the upper housing 231 in the short direction.

  Further, oil discharged from the oil pump 24 (see FIG. 2) and directed toward the oil filter 26 (see FIG. 2) flows through the oil passage of the oil passage portion 231e. Therefore, since the high-pressure oil is supplied to the oil passage of the oil passage portion 231e, the rigidity of the oil passage portion 231e is increased.

  Here, FIG. 5 is a diagram for explaining a planar arrangement position of the balancer device 20 in the crank chamber 19. In FIG. 5, the illustration of the crankshaft 8 and the bearing portions of the crankcase 3 and the like are omitted for ease of viewing.

  As shown in FIG. 5, the crankcase 3 has side walls 3a and 3b, a front end 3c, and a rear end wall 3d. The side walls 3a, 3b and the rear end wall 3d are attached below the cylinder block 1 (see FIG. 1), and the front end 3c is covered with a chain cover 6 (see FIG. 2). A crank chamber 19 is formed by the crankcase 3, the cylinder block 1, the chain cover 6 and the oil pan 4.

  In the present embodiment, the upper housing 231 of the balancer device 20 is disposed in most of the crank chamber 19 as viewed in plan. That is, the upper housing 231 is disposed in a portion excluding the region R in the crank chamber 19 where the oil pump 24 (see FIG. 2) is disposed in a plan view. That is, one end of the upper housing 231 in the short direction (end on the Y1 direction) is disposed in the vicinity of the side wall 3a of the crankcase 3, and the other end in the short direction of the upper housing 231 (on the Y2 direction side). (End part) is arrange | positioned in the vicinity of the side wall 3b of the crankcase 3. As shown in FIG. Further, one end portion (end portion on the X1 direction side) in the longitudinal direction of the upper housing 231 is disposed in the vicinity of the front end 3c of the crankcase 3, and the other end portion (end portion on the X2 direction side) in the longitudinal direction of the upper housing 231 is disposed. ) Is spaced from the rear end wall 3d of the crankcase 3 by a predetermined distance (region R in which the oil pump 24 is disposed). Therefore, the upper housing 231 attached below the cylinder block 1 is provided so as to correspond to (overlap with) most of the cylinder block 1 in the vertical direction.

-Effect-
In the present embodiment, as described above, the upper housing 231 is attached to the cylinder block 1 and the upper housing 231 is disposed in a large part of the crank chamber 19 when seen in a plan view, whereby the balancer device 20 is connected to the internal combustion engine 100. It is possible to contribute to the improvement of rigidity. As a result, the balancer device 20 can improve the rigidity of the internal combustion engine 100, so that the NV (noise vibration) performance can be improved.

  In the present embodiment, the rigidity of the balancer device 20 itself can be improved by integrally forming the plate portion 231d in the upper housing 231, and thus the rigidity of the internal combustion engine 100 can be further improved. The assembly man-hour can be reduced. Further, since the oil flowing along the bottom of the crankcase 3 can be prevented from being affected by the rotation of the crankshaft 8 by the plate portion 231d, the oil used for lubrication and cooling returns to the oil pan 4. It can be made easier.

  In the present embodiment, the rigidity of the balancer device 20 itself can be improved by integrally forming the oil passage portion 231e in the upper housing 231, and thus the rigidity of the internal combustion engine 100 can be further improved. At the same time, the assembly man-hours can be reduced.

  In the present embodiment, oil flowing from the oil pump 24 toward the oil filter 26 flows through the oil passage of the oil passage portion 231e, so that high-pressure oil is supplied to the oil passage portion 231. Therefore, the rigidity of the oil passage portion 231e is increased. Therefore, the rigidity of the balancer device 20 itself can be improved.

  In the present embodiment, the balance shaft 21 is made longer than the balance shaft 22, and a bearing member 233 for rotatably supporting the balance shaft 21 is attached to the plate portion 231d. Since the rigidity of the device 20 itself can be improved, the rigidity of the internal combustion engine 100 can be further improved.

-Other embodiments-
In addition, embodiment disclosed this time is an illustration in all the points, Comprising: It does not become a basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the scope of claims. Further, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the scope of the claims.

  For example, in the present embodiment, an example in which the internal combustion engine 100 is a gasoline engine has been shown, but the present invention is not limited thereto, and the internal combustion engine may be a diesel engine or the like.

  In the present embodiment, the example in which the internal combustion engine 100 is an in-line four cylinder has been described. However, the present invention is not limited to this, and the internal combustion engine may have a number of cylinders other than the in-line four cylinders or a cylinder arrangement. In this case, the number of balance shafts and the number of rotations of the balance shaft relative to the crankshaft may be set according to the number of cylinders and the cylinder arrangement. That is, in the present embodiment, an example in which two balance shafts 21 and 22 are provided and the number of rotations of the balance shafts 21 and 22 is twice that of the crankshaft 8 is shown. A balance shaft may be provided, and the rotation speed of the balance shaft may be the same as that of the crankshaft.

  In the present embodiment, an example in which the internal combustion engine 100 is installed vertically has been described. However, the present invention is not limited thereto, and the internal combustion engine may be installed horizontally.

  Further, in the present embodiment, an example in which the injector 17 that injects fuel into the intake passage 10 is shown, but the present invention is not limited thereto, and an injector that directly injects fuel into the combustion chamber may be provided.

  Further, in the present embodiment, an example in which the upper housing 231 is arranged in a large part (substantially the whole) in the crank chamber 19 as seen in a plan view is shown, but the present invention is not limited to this, and the upper housing is seen in a plan view. You may arrange | position throughout the crank chamber.

  In the present embodiment, the oil pump 24 and the oil pan 4 are disposed on the rear side. However, the present invention is not limited thereto, and the oil pump and the oil pan may be disposed on the front side. In such a case, the oil passage portion 231e may not be provided.

  In this embodiment, the plate portion 231d is disposed on the front side, and the lower housing 232 is disposed on the rear side. However, the present invention is not limited thereto, and the plate portion is disposed on the rear side. The lower housing may be arranged on the front side.

  In the present embodiment, the balance shaft 21 is disposed on the left side (Y2 direction side) and the oil passage portion 231e is disposed on the right side (Y1 direction side). The shaft may be disposed on the right side and the oil passage may be disposed on the left side.

  Further, in the present embodiment, the example in which the power of the crankshaft 8 is transmitted from the front side of the balance shaft 21 is not limited to this, but the power of the crankshaft is transmitted from the rear side of the balance shaft. May be. In such a case, the bearing member 233 may not be provided.

  Further, in the present embodiment, an example in which the crankshaft 8 and the balance shaft 21 are connected via a chain is shown, but the present invention is not limited to this, and the crankshaft and the balance shaft are connected via a gear or a belt. You may make it do.

  The present invention is applicable to a balancer device for an internal combustion engine.

1 Cylinder block 8 Crankshaft 19 Crank chamber 21 Balance shaft (first balance shaft)
22 Balance shaft (second balance shaft)
23 balancer housing 24 oil pump 26 oil filter 100 internal combustion engine 231 upper housing 231d plate portion 231e oil passage portion 232 lower housing 233 bearing member

Claims (4)

A balancer device comprising a balance shaft and a balancer housing on which the balance shaft is rotatably provided,
The balancer housing includes an upper housing and a lower housing,
The upper housing is attached to a lower part of the cylinder block, and is disposed in a large part of the crank chamber in a plan view, and has a plate part disposed under the crankshaft.
The balancer device, wherein the plate portion and the lower housing are arranged adjacent to each other in a longitudinal direction of the upper housing. The balancer device according to claim 1,
The upper housing has an oil passage portion in which an oil passage is formed,
The balancer device, wherein the oil passage portion is formed so as to extend in a longitudinal direction of the upper housing, and is disposed on one side of the upper housing in a short side direction. The balancer device according to claim 2,
The balancer device is configured such that oil discharged from an oil pump and flowing toward an oil filter flows in the oil passage of the oil passage portion. In the balancer apparatus as described in any one of Claims 1-3,
The balance shaft includes a first balance shaft to which power is transmitted from the crankshaft, and a second balance shaft to which power is transmitted from the first balance shaft,
The first balance shaft is disposed on the other side in the short direction of the upper housing, and is formed to have a length in the axial direction larger than that of the second balance shaft.
The balancer device is characterized in that a bearing member for rotatably supporting the first balance shaft is attached to the plate portion.

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