JP6617453B2 - Balancer device - Google Patents

Description

  The present invention relates to an engine balancer device.

  A balancer device may be disposed in the oil pan of the engine. In particular, the balancer device is provided to suppress an increase in engine vibration caused by an imbalance in the rotational balance of the crankshaft caused by the inertial force associated with the reciprocating motion in the vertical direction of each piston of the plurality of cylinders.

  The balancer device includes, for example, a plurality of balancer shafts whose center of gravity is eccentric with respect to the axial center by arranging a balancer weight portion having a semicircular cross section in a predetermined orientation around the axial center, and the balancer shafts. Each housing includes a housing that is rotatably supported about the axis. A housing is arrange | positioned in the oil pan provided in the lower part of an engine (for example, refer patent document 1).

  The housing includes a support portion that rotatably holds shaft portions provided at both end portions in the axial center direction of the balancer weight portion of the balancer shaft. In the support portion, the shaft portion of the balancer shaft is fixed to the housing so as to be rotatable around the shaft center via a slide bearing (metal bearing).

  Oil supply to the slide bearing is performed through a lubricating oil passage provided in the peripheral wall portion of the housing. The housing also functions to isolate the oil in the oil pan from the balancer shaft.

JP 2014-77455 A

  By the way, when a large amount of lubricating oil accumulates in the housing, the balancer shaft is immersed in the lubricating oil, and its rotational resistance increases. High rotational resistance leads to friction loss. For this reason, it is desirable that the lubricating oil be appropriately discharged out of the housing. Therefore, the housing that accommodates the balancer shaft has a structure in which one of the portions is opened so that the lubricating oil does not accumulate inside the housing.

  However, even in a structure in which a part of the housing is opened, there is a concern that the amount of the lubricating oil staying in the housing may increase depending on operating conditions. In Patent Document 1, by providing a concave portion on the outer surface of the balancer shaft, a pressure difference is generated between the concave portion and a portion other than the concave portion to promote the discharge of the lubricating oil in the outer diameter direction. When the amount of oil flowing in is large, there may be a situation where the lubricating oil is not sufficiently discharged out of the housing. Therefore, the balancer device is required to have a higher lubricating oil discharge capability.

  SUMMARY OF THE INVENTION An object of the present invention is to further enhance the capability of discharging the lubricating oil to the outside of the housing in the balancer device.

  In order to solve the above-described problems, the present invention provides a balancer shaft housing disposed in an oil pan of an engine, and a balancer shaft housed in the balancer shaft housing and rotated about an axis in synchronization with rotation of the engine. The balancer shaft includes a shaft portion supported by a support portion provided in the balancer shaft housing, and a balancer weight portion arranged eccentrically with respect to the shaft center of the shaft portion, and the balancer shaft housing The balancer shaft has an opening for discharging a lubricating oil to the outside at one end along the axial direction of the shaft portion, and the balancer shaft on the outer surface of the balancer weight portion facing the inner surface of the balancer shaft housing. The lubricant in the balancer shaft housing is moved forward along the axial direction as the shaft rotates about the axis. The balancer device comprising a first lubricant guiding unit for pressing the opening-side was adopted.

  In this configuration, the balancer shaft includes an end member having a cross-sectional area larger than that of the shaft portion at one end portion along the axial direction, and the balancer shaft housing extends along the axial direction. It is possible to employ a configuration in which a through hole is provided in one end wall and the opening for discharging the lubricating oil is provided between the end member and the inner surface of the through hole.

  Here, the lubricating oil in the balancer shaft housing is moved along the axial direction along the axial direction on the opposing outer surface of the end member facing the inner surface of the through-hole as the shaft rotates about the axial center of the balancer shaft. The structure provided with the 2nd lubricant guide part which presses to can be employ | adopted.

  In each of these configurations, the end member may have a disk shape or a column shape, and the through hole may have a circular cross section as an example.

  Further, the first or second lubricating oil guiding portion may employ a configuration including a protrusion or a recess provided on the outer surface facing the balancer weight portion or the end member.

  The opposite outer surface of the balancer weight portion or the end member is a cylindrical surface, and the lubricating oil guide portion is configured by a protrusion or a groove provided in a direction intersecting the axial direction along the cylindrical surface. Can be adopted.

  A configuration in which the ridge or the groove of the first or second lubricating oil guiding portion is arranged in a spiral shape along the opposing outer surface of the balancer weight portion or the end member can be adopted.

  In each of these configurations, a plurality of the balancer shafts are provided, and the first or second lubricating oil guide portion is provided on the plurality of balancer shafts, and relatively lubricates among the spaces in the balancer shaft housing. Lubricating oil pressing ability of the first or second lubricating oil guiding portion in the balancer shaft arranged on the side where the oil is likely to be accumulated, and lubricating oil pressing force of the first or second lubricating oil guiding portion in the other balancer shaft It is possible to adopt a configuration that is set larger than the capacity.

  The balancer shaft housing includes a partition that divides a space in the balancer shaft housing in the axial direction, the support portion is provided in the partition, and the partition is on both sides of the axial direction with the partition interposed therebetween. The structure provided with the oil passage hole which connects spaces can be employ | adopted.

  According to the present invention, the balancer shaft housing is provided with an opening for discharging lubricating oil to the outside at one end along the axial direction of the balancer shaft, and the axial center of the balancer weight portion provided on the balancer shaft Since the lubricating oil guiding portion that presses the lubricating oil toward the opening along the axial direction along with the peripheral rotation is provided, the capability of discharging the lubricating oil to the outside of the housing in the balancer device can be further enhanced.

The longitudinal cross-sectional view of the engine provided with the balancer apparatus of one Embodiment of this invention The top view which shows the balancer apparatus of the embodiment AA sectional view of FIG. BB sectional view of FIG. CC sectional view of FIG. Left side view of FIG.

  Embodiments of the present invention will be described with reference to the drawings. This embodiment is a balancer device F disposed in an oil pan of the engine, and an engine including the balancer device F.

  The main configuration of the engine includes a block main body E including a cylinder head portion, a cylinder block, a lower block, and the like, and an oil pan 10 connected to a lower portion of the block main body E in order from the upper side to the lower side.

  In many cases, the cylinder axis is inclined with respect to the vertical direction, but FIG. 1 shows an example in which the cylinder axis is oriented in the vertical direction. Further, although the number of cylinders of the engine is arbitrary, FIG. 1 shows only one cylinder.

  The oil pan 10 is fixed to the lower surface of the lower block that constitutes a part of the block body E. A balancer device F is disposed inside the oil pan 10.

  The balancer device F includes two balancer shafts 2 supported by a balancer shaft housing 1 (hereinafter simply referred to as “housing 1”) fixed in the oil pan 10, that is, a drive-side balancer shaft 2 and a follower. It is the structure of a set of two provided with the side balancer shaft 2.

  As shown in FIG. 2, the housing 1 includes support portions 4 that respectively hold a plurality of shaft portions 2 a provided adjacent to the balancer weight portion 2 b of the balancer shaft 2 so as to be rotatable about the axis. In the support portion 4, the shaft portion 2 a of the balancer shaft 2 is supported by the housing 1 via a slide bearing (metal bearing) so as to be rotatable about the axis.

  The balancer weight portion 2b has an unbalanced weight structure having weights in a fixed orientation around the axis of the shaft portion 2a. As shown in FIGS. 1 and 5, the balancer weight portion 2b having a semicircular cross section is arranged in a predetermined orientation around the axis (in the embodiment, an orientation of 180 ° around the axis), so that the center of gravity is The balancer shaft 2 is eccentric with respect to the shaft center of the shaft portion 2a. In the figure, the weight disposition angle of the balancer weight portion 2b is 180 ° around the shaft center of the shaft portion 2a. However, the disposition angle of the weight and the outer surface shape can be freely set according to engine specifications and the like. Here, the reference c0 in the figure is the axis of the shaft portion 2a.

  Oil supply to the slide bearing is performed through a lubricating oil passage (not shown) provided in the peripheral wall portion of the housing 1.

  The driving force is transmitted to the balancer shaft 2 through the driving force transmitting member 2e. In this embodiment, the driving force transmission member 2e includes a sprocket provided at the shaft end of the crankshaft C supported by the block body E and a shaft end on one side of the drive-side balancer shaft 2 shown on the upper side in FIG. And a sprocket or the like provided in the above is connected by an endless member such as a chain. The rotation transmitted from the crankshaft C of the engine through the driving force transmission member 2e is transmitted to the balancer shaft 2 on the driving side.

  Further, a driving gear 2c provided at the other shaft end of the driving balancer shaft 2 and a driven gear provided at the other shaft end of the driven balancer shaft 2 shown in the lower side of FIG. 2c is engaged. Each gear 2c is accommodated in a gear accommodating portion 42 provided on the outer side in the axial center direction than the support portion 4 on the right side in FIG.

  In addition, a disc-shaped or columnar end member 2d is provided at the end of the balancer shaft 2 opposite to the gear 2c. The end member 2 d is a member that is provided at one end of the balancer shaft 2, has a larger cross-sectional area in the direction perpendicular to the shaft center than the shaft portion 2 a, and is provided on the end surface of the housing 1. The end member 2 d rotates with the rotation of the balancer shaft 2. The end member 2d is disposed at an end of an end member storage portion 43 provided on the outer side in the axial direction from the left support portion 4 in FIG. Is a weir member. This weir member prevents the lubricating oil from flowing into the housing 1.

  The housing 1 includes partition walls 1d and 1e that partition the space in the housing 1 in the axial direction. The partition walls 1d and 1e are provided at two locations along the axial direction. The partition wall 1 d on one side in the axial direction partitions the main space 41 and the end member storage portion 43 in the casing 1. Further, the partition wall 1 e on the other side in the axial direction partitions the main space 41 and the gear housing portion 42 in the casing 1. In this embodiment, the balancer weight portion 2b is disposed in the main space 41, the end member storage portion 43, and the gear storage portion 42, but this may be the main space 41 alone.

  That is, the main space 41 is a space surrounded by the bottom portion 1a, the side portions 1b on both sides, the partition walls 1d and 1e, and the ceiling portion 1c. The gear housing part 42 is a space surrounded by the bottom part 1a, the end wall 1f, the side parts 1b on both sides, and the partition walls 1e, and the upper part is open. The end member storage portion 43 is a space surrounded by the bottom portion 1a, the end wall 1g, the side portions 1b on both sides, the partition wall 1d, and the ceiling portion 1c.

  The support portion 4 of the balancer shaft 2 is provided on the partition walls 1d and 1e. Further, the partition wall 1d on one axial direction side is provided with an oil passage hole 30 that connects the spaces on both sides in the axial center direction, that is, the main space 41 and the end member housing portion 43 with the partition wall 1d interposed therebetween. . The oil passage hole 30 opens in a relatively lower portion of each space of the main space 41 and the end member storage portion 43.

  The housing 1 includes an opening 33 for discharging a lubricating oil that communicates with the outside at an end portion on one side along the axial direction. In this embodiment, the lubricating oil discharge opening 33 includes a through hole 1 h provided in the end wall 1 g on one side in the axial center direction of the housing 1, and an opposing outer surface of the end member 2 d facing the inner surface of the housing 1. It consists of a gap between. Since the end member 2d has a disk shape or a columnar shape, and the through hole 1h has a circular shape with a slightly larger diameter than the end member 2d, the lubricating oil discharge opening 33 is an annular opening. ing.

  On the opposite outer surface of the balancer weight portion 2b facing the inner surface of the housing 1, the lubricating oil in the housing 1 is rotated along the axial direction along one axis, that is, for discharging the lubricating oil as the balancer shaft 2 rotates about the axial center. A lubricating oil guiding portion 20 that presses toward the opening 33 is provided.

  In this embodiment, the opposing outer surface of the balancer weight portion 2b is a cylindrical surface, and the lubricating oil guide portion 20 is configured by a spiral groove provided in a direction intersecting the axial direction along the cylindrical surface. .

  In addition, on the opposite outer surface of the end member 2d facing the inner surface of the through hole 1h, the lubricating oil in the housing 1 is rotated along the axial direction along one axis, that is, lubricated as the balancer shaft 2 rotates about the axial center. A lubricating oil guide portion 21 that presses toward the oil discharge opening 33 is provided.

  In this embodiment, the opposing outer surface of the end member 2d is also a cylindrical surface, and the lubricating oil guiding portion 21 is configured by a spiral groove provided in a direction intersecting the axial direction along the cylindrical surface. The

  The rotation of the crankshaft C is transmitted to the drive-side balancer shaft 2 by the operation of the engine, and the rotation of the drive-side balancer shaft 2 is transmitted to the driven-side balancer shaft 2 through the drive-side gear 2c and the driven-side gear 2c. Is done.

  For example, the number of teeth of the sprocket of the crankshaft C is set to twice the number of teeth of the sprocket of the balancer shaft 2 on the driving side, and the number of teeth of the driving side gear 2c is set equal to the number of teeth of the driven side gear 2c. Suppose that In this case, the drive-side balancer shaft 2 and the driven-side balancer shaft 2 rotate in the opposite directions around the axis center at a rotational speed twice that of the crankshaft C (arrows a and b in FIG. 1). reference).

  By the rotation of the balancer shaft 2, the unbalanced inertial force generated through the crankshaft C can be canceled, and low-frequency rigid body vibrations and vehicle interior noise can be kept low.

  The bottom 1 a of the housing 1 is located above the upper surface of the bottom of the oil pan 10. Moreover, the housing 1 is a position which does not interfere with the crankshaft C or the locus D of the lower end of the connecting rod, as shown in FIG.

  In this embodiment, as indicated by arrows a and b in FIG. 1, the two balancer shafts 2 rotate in opposite directions, so that the lubricating oil L in the housing 1 is in the vicinity of the center in the figure, that is, 2 In a space t sandwiched between the balancer shafts 2, the balancer weight portion 2b having a sectoral cross section is pressed in the direction of arrows c and d from the bottom to the top by a flat surface along the sector bus. At this time, the opposed outer surface formed by the cylindrical surface of the balancer weight portion 2 b always maintains a predetermined gap with the inner surface of the housing 1.

  The main space 41 in the housing 1 is a sealed space that is separated from the outside in an air-tight and liquid-tight manner except for the sliding surface of the intake hole 3 and the support portion 4. The end member storage portion 43 is also a sealed space separated from the outside in an airtight and liquid tight manner. However, the gear storage portion 42 is a space that is largely open upward.

  Further, as the balancer shaft 2 rotates, the lubricating oil in the main space 41 of the housing 1 is pressed against the edge of the lubricating oil guiding portion 20 formed of a concave groove and is sent out from the other side in the axial direction to one side. Then, the oil enters the end member housing portion 43 through the oil passage hole 30 of the partition wall 1d.

  The lubricating oil guide portion 20 is configured and configured to press the lubricating oil from the other side in the axial direction to the one side in accordance with the rotation of each balancer shaft 2 on the driven side and the driving side. Here, the concave groove is spirally formed in such a manner that the direction around the axis center on the other side in the axial center direction precedes the direction around the axis center on the one side in the axial direction along the rotation direction of each balancer shaft 2. Is formed.

  Further, due to the rotation of the balancer shaft 2, the lubricating oil in the end member housing portion 43 of the housing 1 is also pressed against the edge of the lubricating oil guiding portion 21 formed of a concave groove, and from the other side in the axial direction to one side. To be sent to. Then, the oil is sent out of the housing 1 through the opening 33 for discharging the lubricating oil. The sent lubricating oil falls onto the oil pan 10.

  The lubricating oil guide portion 21 of the end member 2d has a shape and arrangement that presses the lubricating oil from the other side in the axial direction to the one side as the driven balancer shaft 2 rotates. Here, the concave groove is formed in a spiral shape along the rotation direction of the balancer shaft 2 such that the orientation around the axis center on the other side in the axial direction precedes the orientation around the axis center on the one side in the axial direction. Has been. The lubricating oil is guided in the direction of the arrow indicated by the broken line in FIGS.

  In this embodiment, the end member 2d of the drive-side balancer shaft 2 is not provided with the lubricating oil guiding portion 21, but the end portion member 2d of the driving-side balancer shaft 2 is also provided with the lubricating oil guiding portion 21. Also good. Further, the lubricating oil guiding portion 20 may be provided on the opposite outer surface of the balancer weight portion 2 b in the end member storage portion 43.

  Further, when the lubricating oil discharging function is sufficient, the installation of the lubricating oil guiding portion 21 may be omitted in the end members 2d of all balancer shafts 2. At this time, the opening 33 for discharging the lubricating oil communicating with the outside of the housing 1 can be configured by providing a through hole that connects the inside and outside of the housing 1 in the end wall 1g. The opening 33 can have the same diameter and height as the oil passage hole 30.

  As described above, the lubricating oil in the housing 1 flows from the bottom portion 31 in the main space 41 through the oil passage hole 30 to the bottom portion in the end member storage portion 43 by the action of the lubricating oil guide portion 20 of the balancer weight portion 2b. 32. Further, in the end member storage portion 43, when the lubricating oil guide portion 20 is provided also in the action of the lubricating oil guide portion 21 of the end member 2 d or the balancer weight portion 2 b in the end member storage portion 43. Is promptly guided out of the housing 1 through the opening 33 from the bottom 32 in the end member housing portion 43 by the action of the lubricating oil guiding portion 20 of the balancer weight portion 2b.

  In this embodiment, the lubricating oil guide portions 20 and 21 are constituted by concave grooves arranged spirally along a cylindrical surface that is an outer surface facing the balancer weight portion 2b and the inner surface of the housing 1 of the end member 2d. The lubricating oil guide portions 20 and 21 may be configured by ridges arranged in a spiral shape along a cylindrical surface which is an outer surface facing the balancer weight portion 2b or the end member 2d.

  Alternatively, the lubricating oil guide portions 20 and 21 may have a configuration other than the spiral shape. For example, you may comprise the protrusion or groove | channel provided in the direction which cross | intersects an axial center direction along the cylindrical surface which is an opposing outer surface of the balancer weight part 2b or the edge part member 2d. The ridge or the groove may be formed in a straight line, a curved line such as an arc, or a combination thereof. At this time, the ridge or the groove is formed in a direction in which the direction around the axis center on the other side in the axial direction precedes the direction around the axis on the one side in the axial direction along the rotation direction of each balancer shaft 2. It is desirable to form.

  The lubricating oil guide portions 20 and 21 may be a set of protrusions or a set of recesses provided on the outer surface of the balancer weight portion 2b or the end member 2d facing the inner surface of the housing 1, or a combination thereof.

  Further, the effect of the lubricating oil guiding portions 20 and 21 is not limited to the case where the opposing outer surfaces of the balancer weight portion 2b and the end member 2d are cylindrical surfaces as in this embodiment. However, the effect can be exhibited also when it is constituted by a combination of planes like the side surface of the polygonal column.

  Furthermore, the lubricating oil pressing ability of the lubricating oil guiding portions 20 and 21 in the balancer shaft 2 that is disposed on the side where the lubricating oil is relatively likely to accumulate in the space in the housing 1 is determined as the lubricating oil induction in the other balancer shaft 2. It can be set larger than the lubricating oil pressing ability of the parts 20 and 21. In this way, the lubricating oil can be discharged more promptly in the area where the lubricating oil tends to accumulate.

  For example, when the engine is inclined and fixed, the balancer shaft 2 on the side where the lubricating oil is likely to accumulate is the balancer shaft 2 located on the relatively lower side.

  As a technique for increasing the lubricating oil pressing ability of the lubricating oil guiding portion 20, for example, increasing the depth of the concave portion or the concave groove or increasing the width thereof can be mentioned. Moreover, shortening the space | interval of an adjacent recessed part and a ditch | groove, and increasing the number is mentioned. Similarly, increasing the height of the protrusions and ridges and increasing the width thereof can be mentioned. Moreover, shortening the space | interval of adjacent protrusions and protrusions and increasing the number is mentioned.

  In these embodiments, the two balancer shafts 2 are accommodated in the housing 1, but the number of the balancer shafts 2 is not limited to two, and the aspect in which the single balancer shaft 2 is accommodated in the housing 1, A mode in which three or more balancer shafts 2 are accommodated in the housing 1 is also conceivable.

1 Balancer shaft housing (housing)
1a Bottom 1b Side 1c Ceiling 1d, 1e Partition 1f, 1g End wall 1h Through hole 2 Balancer shaft 2a Shaft 2b Balancer weight 2c Gear 2d End member 2e Driving force transmitting member 3 Intake hole 10 Oil pan 11 Lubricating oil Reservoir parts 20, 21 Lubricating oil guiding part 30 Oil passage hole 33 Opening C Crankshaft D Trajectory of lower end of connecting rod E Block body F Balancer device L Lubricating oil

Claims (7)

A balancer shaft housing disposed within the oil pan of the engine;
A balancer shaft housed in the balancer shaft housing and rotating around the axis in synchronization with the rotation of the engine;
The balancer shaft includes a shaft portion supported by a support portion provided in the balancer shaft housing and a balancer weight portion arranged eccentrically with respect to the shaft center of the shaft portion,
The balancer shaft housing includes an opening for discharging a lubricating oil that communicates with the outside at one end along the axial direction of the shaft portion,
Lubricating oil in the balancer shaft housing is pressed to the opening side along the axial center direction on the outer surface of the balancer weight portion facing the inner surface of the balancer shaft housing as the balancer shaft rotates about the axial center. A first lubricating oil guiding portion that
The balancer shaft includes an end member having a cross-sectional area larger than that of the shaft portion at an end portion on one side along the axial direction, and the balancer shaft housing has an end on one side along the axial direction. A wall is provided with a through hole, and the gap between the end member and the inner surface of the through hole is an opening for discharging the lubricating oil,
Lubricating oil in the balancer shaft housing is pressed toward the opening along the axial direction on the opposing outer surface of the end member facing the inner surface of the through-hole as the shaft rotates around the axial center of the balancer shaft. A balancer device comprising a second lubricating oil guide. The end member is disk-shaped or cylindrical,
The balancer device according to claim 1, wherein the through hole has a circular cross section. 3. The balancer device according to claim 1, wherein the first or second lubricating oil guide portion includes a protrusion or a recess provided on an opposite outer surface of the balancer weight portion or the end member. The opposing outer surface of the balancer weight portion or the end member is a cylindrical surface, and the first or second lubricating oil guiding portion is a protrusion or a recess provided in a direction intersecting the axial direction along the cylindrical surface. The balancer device according to claim 3 , comprising a groove. 5. The balancer device according to claim 4 , wherein the protrusion or the groove of the first or second lubricating oil guiding portion is disposed in a spiral shape along the opposing outer surface of the balancer weight portion or the end member. A plurality of the balancer shafts;
The first or second lubricant guide part is provided on a plurality of the balancer shafts,
Of the space in the balancer shaft housing, the lubricating oil pressing ability of the first or second lubricating oil guiding portion in the balancer shaft that is disposed on the side where the lubricating oil is likely to accumulate is compared with that in the other balancer shaft. The balancer device according to any one of claims 1 to 5 , wherein the balancer device is set to be larger than a lubricating oil pressing ability of the first or second lubricating oil guiding portion. The balancer shaft housing includes a partition that divides a space in the balancer shaft housing in the axial direction,
The support is provided on the partition;
The balancer device according to any one of claims 1 to 6 , wherein the partition wall includes an oil passage hole that connects spaces on both sides in the axial direction with the partition wall interposed therebetween.

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