JP2015230019A - Internal combustion engine balancer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine balancer device capable of efficiently collecting oil filled in a housing and effectively discharging the oil from an oil discharge hole into an oil pan.SOLUTION: An internal combustion engine balancer device comprises: a housing attached to an internal combustion engine; a drive shaft 8 rotatably contained in the housing; a drive counterweight 26 protruding from an outer circumferential surface of the drive shaft 8 in a radial direction and including a flat portion 26a in a shaft rotation direction; and an oil discharge hole provided at a position facing the flat portion 26a of the counterweight 26 at a predetermined rotation position of the housing and communicating an inside with an outside of the housing, a collection groove 32 that includes a collection tapered surface 33 inclined downward from a proximal edge 33a of the counterweight 26 near the shaft 8 to a tip edge 33b in the radial direction and two sidewall surfaces 34, 34 rising generally perpendicularly from two side edges of the collection tapered surface 33, respectively being provided in the flat portion 26a.

Description

  The present invention relates to a balancer device that reduces secondary vibration caused by rotation of an internal combustion engine.

  As this type of conventional balancer device, one described in Patent Document 1 below is known. Briefly, the balancer device includes a balancer housing disposed inside the oil pan, a drive shaft and a driven shaft that are rotatably supported inside the balancer housing, and cross sections formed on the shafts. A balancer weight having a semicircular arc shape, and openings formed at upper positions of the two shafts of the balancer housing are provided.

  Both the balancer weights have a flat surface portion for scraping out the oil filled in the balancer housing, and an oil extrusion surface that is inclined in the direction opposite to the rotation direction toward the outer diameter direction is formed on the front end side of the flat surface portion. Is formed. In addition, inclined surfaces that are inclined so as to narrow toward the oil extrusion surface are formed at both ends of the oil extrusion surface in the drive shaft axial direction.

  These oil extrusion surfaces and both inclined surfaces are configured to extrude oil received by the flat portion toward an opening formed in the upper portion of the balancer housing. That is, the oil push-out surface and the both inclined surfaces define the oil push-out direction.

Japanese Patent Laid-Open No. 9-14354

  However, the oil push-out surface is formed on the front end side of the flat portion in order to ensure directionality, and the both inclined surfaces are formed in an inclined shape opened outward in the drive shaft axial direction. Therefore, the oil received at the flat surface escapes from the oil extrusion surface and both inclined surfaces to the outside, and it becomes difficult to sufficiently collect the oil here, and the discharge efficiency from the opening portion decreases. .

  The present invention has been devised in view of the actual situation of the conventional balancer device. By sufficiently collecting the oil filled in the housing by the collection groove of the balancer weight, It is an object of the present invention to provide a balancer device for an internal combustion engine that can improve the efficiency of discharge into the engine.

  The present invention provides a housing attached to an internal combustion engine, a balancer shaft rotatably accommodated in the housing, a radial projection from an outer peripheral surface of the balancer shaft, and a rotation direction of the balancer shaft A balancer weight having a flat part on the side, and an opening provided at a position facing the flat part at a predetermined rotational position of the balancer weight of the housing, and communicating with the inside and outside of the housing. A collecting taper surface inclined downward from a base end edge in the vicinity of the balancer shaft of the balancer weight toward a distal end edge in a radial direction, and both side wall surfaces rising substantially perpendicularly from both side edges of the collecting taper surface; It is characterized in that a collecting groove comprising

  According to the present invention, the oil filled in the housing can be efficiently collected by the collection groove of the balancer weight, and can be effectively discharged into the oil pan from the opening. As a result, the friction generated between the oil and the balancer weight at an early stage can be reduced.

It is a front view showing the state where the balancer device of a 1st embodiment was provided in the internal-combustion engine concerning the present invention. It is a perspective view which decomposes | disassembles and shows the drive side and hydraulic tensioner of the balancer apparatus in this embodiment. It is a disassembled perspective view of the balancer device. It is a bottom view of the balancer device with the oil pan removed. It is the sectional view on the AA line of FIG. It is a perspective view of the drive shaft and driven shaft in this embodiment. It is a top view which expands and shows the principal part of the counterweight in this embodiment. FIG. 2 is a perspective view of the counterweight, and FIG. 2B is a cross-sectional view showing an operation state when the counterweight scoops up the oil. It is the principal part bottom view which showed the relationship between the position of the counterweight and an oil discharge hole, and a magnitude | size. It is an AA line sectional view of Drawing 4 in a 2nd embodiment. It is principal part sectional drawing of the balancer apparatus in 2nd Embodiment.

Hereinafter, a balancer device for an internal combustion engine according to the present invention will be described with reference to the drawings. In this embodiment, the present invention is applied to an in-line four-cylinder gasoline internal combustion engine.
[First Embodiment]
As shown in FIGS. 1 to 3, a bearing portion that pivotally supports the crankshaft 2 and a crankcase 3 having a substantially U-shaped cross section are fixed to the lower portion of the cylinder block 1 of the internal combustion engine. An oil pan 4 in which engine oil O is stored is attached to the outer peripheral edge of the lower portion of 3. The internal combustion engine is arranged in an inclined shape with the left side lowered in FIG. 1 due to the layout in the engine room.

  The crankshaft 2 is rotatably supported by a plurality of bearings composed of bearing caps and the like that are coupled to the lower portion of the cylinder block 1 by bearing bolts (not shown). A sprocket 5 is attached. The crank sprocket 5 is coupled to the front end portion 2a of the crankshaft 2 by shrink fitting through an insertion hole 5a formed in the center portion, and has a gear tooth portion 5b on the outer periphery.

  The crankcase 3 has a plurality of bolt insertion holes 3a through which attachment bolts (not shown) for attachment to the cylinder block 1 are inserted at predetermined positions on the upper end. Further, a semicircular cutout portion 3b through which a distal end portion 8a of a drive shaft 8 described later is inserted is formed on the front end surface of the crankcase 3.

  In the space surrounded by the lower surface of the crankcase 3 and the oil pan 4, a balancer device 6 for suppressing secondary vibration of the internal combustion engine is accommodated and disposed as shown in FIG.

  As shown in FIG. 5, the balancer device 6 is disposed so as to be inclined at the same angle as the inclination angle of the internal combustion engine so that the driven shaft 9 side, which will be described later, is lower than the drive shaft 8 side in the gravity direction. Has been placed.

  As shown in FIGS. 3 and 5, the balancer device 6 includes a housing 7 formed in a rectangular box shape having the lower part of the crankcase 3 as a part of the structure, and a rotatable inside the housing 7. A drive shaft 8 that is a drive-side balancer shaft and a driven shaft 9 that is a driven-side balancer shaft that are supported and arranged in parallel in the longitudinal direction of the engine, and are fixed to the rear ends of both shafts 8 and 9 by press-fitting or the like. And a helical drive side gear 10 and a driven side gear 11 in which the respective tooth portions mesh with each other.

  The housing 7 includes a housing body 12 formed in a box shape with an aluminum alloy material, and a cover portion 13 that is integrally formed at a lower portion of the crankcase 3 and closes an upper end opening of the housing body 12. ing.

  As shown in FIGS. 3 and 5, the housing main body 12 has left and right frame-shaped deck portions 12a and 12a formed on the outer peripheral portion of the joint portion facing the cover portion 13 from above and below. A pair of front and rear parallel first and second transverse beam deck portions 12b and 12c are continuously formed between the shaped deck portions 12a and 12a.

  Bolt insertion holes 15 through which fastening bolts 14 for fixing the housing body 12 to the cover portion 13 are inserted are formed at predetermined positions of the frame-shaped deck portions 12a and 12a and the horizontal frame deck portions 12b and 12c. On the other hand, a female screw hole 13 a into which the fastening bolt 14 is screwed is formed at a position corresponding to the bolt insertion hole 15 of the cover portion 13.

  The housing body 12 has an oil strainer 16 at the lower end thereof for filtering the oil O stored in the oil pan 4.

  As shown in FIGS. 1 and 2, the drive shaft 8 is fixed to a tip end portion 8 a protruding from the notch portion 3 b of the crankcase 3 by a mounting bolt 17 a in which a balancer sprocket 17 is screwed from the axial direction. . The balancer sprocket 17 has a gear tooth portion 17 b on the outer periphery, and a drive chain 18 is wound between the gear tooth portion 17 b and the crank sprocket 5.

  Therefore, when the drive shaft 8 rotates as the balancer sprocket 17 rotates, the drive side gear 10 rotates simultaneously with the driven side gear 11 rotating in the opposite direction to the drive side gear 10, and the driven side A gear 11 rotates the driven shaft 9. The shafts 8 and 9 are set to rotate twice per rotation of the crankshaft 2.

  Further, a hydraulic tensioner 19 screwed and fixed to the front end surface of the crankcase 3 by a mounting bolt 19a is arranged on the outer surface of the drive chain 18 so as to press.

  As shown in FIGS. 3 and 6, the drive shaft 8 has three cylindrical journal surfaces 8d, 8b, and 8c at the central front end side, the central side, and the rear end side in the axial direction. Is formed.

  Among these, the journal surfaces 8b and 8c on the center side and the rear end side are the first and second transverse beam deck portions 12b and 12c of the housing body 12, and the first and second transverse beam deck portions 12b and 12b of the cover portion 13, respectively. It is rotatably supported via two upper and lower plain bearings 20a, 20b, 21a, 21b in two semicircular bearing grooves provided respectively at predetermined positions between the surface corresponding to 12c. The plain bearings 20a, 20b, 21a, 21b are supplied with lubricating oil O via oil grooves (not shown).

  Further, the journal surface 8d on the front end side is rotated through a bearing portion comprising a bearing groove provided in the lower portion of the crankcase 3 and a cap 23 coupled to the lower portion of the crankcase 3 by two bolts 22. It is supported freely.

  On the other hand, the driven shaft 9 has an axial length shorter than that of the drive shaft 8 as shown in FIGS. 3 and 6, and an oil pump (not shown) is provided at the tip 9a. Yes.

  The driven shaft 9 is formed with two cylindrical journal surfaces 9b and 9c at two locations on the front end side and the rear end side in the axial direction, respectively, and the journal surfaces 9b and 9c Each 2 provided at a predetermined position between the first and second transverse beam deck portions 12b and 12c of the housing body 12 and the surface corresponding to the first and second transverse beam deck portions 12b and 12c of the cover portion 13 respectively. Two semicircular arc-shaped bearing grooves are rotatably supported via upper and lower plain bearings 24a, 24b, 25a, 25b. The plain bearings 24a, 24b, 25a, 25b are supplied with lubricating oil O via oil grooves (not shown).

  Further, a drive-side counterweight 26, which is a balancer weight, is integrally provided between the center-side journal surface 8b and the rear-end-side journal surface 8c of the drive shaft 8, whereas the front-end side of the driven shaft 9 is provided. A driven counterweight 27, which is a balancer weight, is integrally provided between the journal surface 9b and the rear end side journal surface 9c.

  Since the drive-side counterweight 26 and the driven-side counterweight 27 have the same basic configuration, the drive-side counterweight 26 will be mainly described below.

  6 to 8, the drive side counterweight 26 has a semi-cylindrical shape from the rear end edge of the center side journal surface 8b of the drive shaft 8 to the front end edge of the rear end side journal surface 8c (cross section). It is formed in a semicircular arc shape. That is, the drive-side counterweight 26 has two flat portions 26a and 26a formed on both sides of the axis of the drive shaft 8, and the circumference of the drive shaft 8 from the two flat portions 26a and 26a. And a weight part 26b having a semicircular cross-sectional shape projecting in one direction.

  The driven-side counterweight 27 has two flat portions 27a, 27a formed on both sides of the driven shaft 9 with respect to the axis, and one side of the circumference of the driven shaft 9 from the two flat portions 27a, 27a. And a weight portion 27b having a semicircular cross section extending to the top.

  Further, as shown in FIG. 5, a lower wall 28 having a circular cross section formed integrally with the housing body 12 and an upper portion of the lower wall 28 are disposed around the counterweights 26 and 27. The weight chamber 30 is formed by an upper wall 29 formed integrally with the cover portion 13 and the first and second transverse beam deck portions 12b and 12c. The weight chamber 30 includes both counters. The weights 26 and 27 are accommodated rotatably.

  Further, as shown in FIG. 5, the maximum oil level L of the oil O returned and stored in the oil pan 4 when the engine is stopped is stored in the weight chamber 30 at a substantially central position in the vertical direction of the weight chamber 30. It is filled to become.

  Further, the upper end portion of the weight chamber 30 communicates with the outside of the weight chamber 30 through two oil discharge holes 31, 31 which are openings provided in the upper wall 29.

  That is, as shown in FIGS. 5, 7, and 9, each of the oil discharge holes 31, 31 has both side edges in the radial direction of the drive shaft 8 of the upper wall 29, that is, the drive side counterweight 26. A width of the drive shaft 8 in the axial direction is formed at a position facing the flat portion 26a at a predetermined rotational position and a position facing the flat portion 27a at a predetermined rotational position of the driven counterweight 27, respectively. The predetermined width length W1 is set.

  Further, as shown in FIG. 6, collecting grooves 32 and 32 are respectively formed in the respective flat portions 26 a and 26 a of the drive-side counterweight 26 at approximately the center position in the axial direction of the drive shaft. The flat grooves 27a and 27a of the driven-side counterweight 27 are also formed with collecting grooves 32 and 32 at substantially the center position in the axial direction of the driven shaft 9, respectively.

  In the description here, since the collection grooves 32, 32, 32, 32 are all the same configuration, for the sake of convenience, only the collection grooves 32, 32 on the drive side counterweight 26 side are performed, and the driven Description of the collecting grooves 32, 32 of the side counterweight 27 is omitted.

  Each of the collecting grooves 32 includes a collecting tapered surface 33 and both side wall surfaces 34 and 34 that rise from both side edges of the collecting tapered surface 33 and are connected to the flat portion 26a.

  As shown in FIGS. 6 to 8, the collecting taper surface 33 is directed from the base end edge 33 a on the drive shaft 8 side of the flat portion 26 a toward the distal end edge 33 b in the radial direction of the drive side counterweight 26. It is formed in a downward slope with a predetermined angle.

  At this time, as shown in FIG. 8B, the collecting taper surface 33 has an extension line in the radial direction of the drive side counterweight 26 of the drive shaft 8 as indicated by a one-dot chain line X in the figure. It is preferable that the axis coincides with the axis P or passes through a position (for example, point P1) opposite to the drive side counterweight 26 from the axis P of the drive shaft 8 as indicated by a one-dot chain line Y in the figure. Thereby, the depth of each collection taper surface 33 and 33 is set to below predetermined. In this embodiment, the extension line of the collecting taper surface 33 in the radial direction of the drive side counterweight 26 coincides with the axis P of the drive shaft 8.

  Further, as shown in FIG. 7, both end edges of the collecting taper surface 33 in the axial direction of the drive shaft 8 have a substantially C-shape that gradually increases in diameter from the base end edge 33a toward the front end edge 33b. Is formed. That is, when the width length W2 on the base end edge 33a side in the axial direction of the drive shaft 8 is compared with the width length W3 on the front end edge 33b side, the collection taper surface 33 has a width length W3 on the front end edge 33b side. Is set to be longer (W2 <W3).

  Further, as shown in FIG. 9, the width W3 of the collecting taper surface 33 on the tip edge 33b side in the drive shaft 8 axis direction is the axial length of the oil discharge holes 31 and 31 in the drive shaft 8 axis direction. It is formed to be smaller than the width length W1 (W3 <W1).

As described above, the both side wall surfaces 34, 34 rise substantially perpendicularly from both edges of the collecting taper surface 33 in the axial direction of the drive shaft 8, and thus the drive shaft between the both side wall surfaces 34, 34. Similarly to the collecting taper surface 33, the distance (width length) in the eight-axis direction is substantially C-shaped and gradually increases from the position of the base end edge 33a of the collecting taper surface 33 toward the position of the tip end edge 33b. Is formed. Further, the heights of both side wall surfaces 34, 34 are formed so as to gradually increase from the position of the base end edge 33a of the collection taper surface 33 toward the position of the front end edge 33b according to the taper angle of the collection taper surface 33. .
[Operation of this embodiment]
According to the balancer device 6, when the engine is started and the crankshaft 2 is rotationally driven, the drive shaft 8 is driven at twice the speed of the crankshaft 2 via the crank sprocket 5, the drive chain 18 and the balancer sprocket 17. Rotate. As a result, the driven shaft 9 rotates at the same speed in the opposite direction to the drive shaft 8 through the meshing rotation transmission between the driving gear 10 and the driven gear 11.

  As a result, the counterweights 26 and 27 on the driving side and the driven side also rotate in the opposite directions to cancel the left and right centrifugal forces of the shafts 8 and 9 themselves, and generate an excitation force only in the vertical direction. Thus, as the shafts 8 and 9 rotate, the counterweights 26 and 27 rotate to transmit the excitation force to the internal combustion engine, thereby suppressing secondary vibration.

  At this time, the oil O filled in the weight chamber 30 is scooped up while being collected by the collecting grooves 32 and 32 as the counterweights 26 and 27 are rotated. As shown in FIG. 2, the oil is ejected by being pushed out toward the oil discharge holes 31, 31 respectively.

  More specifically, as shown in FIGS. 8A and 8B, the oil O filled in the weight chamber 30 is moved to the drive side counter weight 26 as the drive side counterweight 26 rotates. A large amount is collected on the entire surface of the collection taper surface 33 by being taken in from the tip edge 33 b side of the collection taper surface 33 on the weight 26 and flowing from here toward the base edge 33 a.

  The oil O collected on the collecting taper surface 33 is blocked by the side wall surfaces 34 and 34 rising from the collecting taper surface 33 even during the scraping operation. The drive shaft 8 is held without spilling from both side edges in the axial direction. Thereafter, as shown in FIG. 5, the oil O collected in the collection groove 32 is pushed out toward the oil discharge hole 31 and discharged as it is.

  In the present embodiment, as described above, the extension line (X) in the radial direction of the drive-side counterweight 26 of the collecting taper surface 33 coincides with the axis P of the drive shaft 8. Since it is formed (see FIG. 8B), the oil O collected on the entire collection taper surface 33 becomes easy to move from the base end edge 33a side to the front end edge 33b side. Since the oil is pushed out toward the oil discharge hole 31, the oil O can be discharged efficiently.

  As shown in FIG. 8B, the effect is that the extension line in the radial direction of the drive-side counterweight 26 of the collecting taper surface 33 is positioned on the opposite side of the drive-side counterweight 26 from the axis P. The same effect can be obtained when it is formed so as to pass through.

  On the other hand, when the extension line is formed so as to pass through the position on the drive side counterweight 26 side from the axis P as indicated by the Z line in FIG. Part of the collected oil O moves from the distal end edge 33b side to the proximal end edge 33a side. For this reason, the amount of oil pushed out from the tip edge 33b toward the oil discharge hole 31 decreases, and the oil O discharge efficiency may be reduced.

  Further, since the collecting taper surface 33 is formed in a substantially C shape that gradually increases from the base end edge 33a toward the front end edge 33b, the intake area on the front end edge 33b side is increased, and more oil O Is taken in from the leading edge 33 b and collected on the collecting taper surface 33.

  Further, since the both side wall surfaces 34, 34 are formed in a substantially C shape that gradually increases from the position of the base end edge 33a of the collecting taper surface 33 toward the position of the front end edge 33b, the side wall 34, 34 is captured from the front end edge 33b side. The oil O taken in on the collecting taper surface 33 is gathered toward the central position of the drive shaft 8 axial direction of the base end edge 33a by the both side wall surfaces 34, 34, thereby more reliably on the collecting taper surface 33. Retained. When the drive-side counterweight 26 is rotated, when being discharged from the collecting groove 32, the drive-side counterweight 26 is smoothly pushed toward the oil discharge hole 31 along the side wall surfaces 34, 34.

  Therefore, the oil O filled in the weight chamber 30 is quickly discharged into the oil pan 4 by the collecting action by the collecting groove 32 and the pushing action toward the oil discharge hole 31.

  Further, since the oil discharge hole 31 is formed at a position facing the flat portion 26a at a predetermined rotational position of the drive side counterweight 26, the oil discharge hole 31 is pushed out from the collecting groove 32 by the rotational force of the drive side counterweight 26. The oil O jumps out toward the oil discharge hole 31 as it is. Thus, the oil O can be smoothly taken into the oil discharge hole 31 and discharged from here into the oil pan 4.

  Furthermore, as shown in FIG. 9, the width W1 of the oil discharge hole 31 in the direction of the drive shaft 8 axis is formed larger than the width length W3 of the collection taper surface 33 in the direction of the drive shaft 8 axis. Therefore, the oil O pushed out from the collecting groove 32 by the rotational force of the driving side counterweight 26 can be efficiently taken into the oil discharge hole 31 and discharged into the oil pan 4.

  As described above, in the present embodiment, the oil O in the weight chamber 30 can be quickly reduced, so that the friction generated between the oil O and the driving side counterweight 26 can be reduced. In particular, in a situation where a large amount of oil O is filled in the weight chamber 30 immediately after the engine is started, the oil O in the weight chamber 30 is quickly reduced, and the oil O and the drive side counterweight 26 It is necessary to reduce the friction generated during this period, and this embodiment is effective.

In the above description, for the sake of convenience, only the operational effects associated with the rotation of the drive shaft 8 are described. However, the operational effects similar to those on the driving side can be obtained on the driven side.
[Second Embodiment]
FIG. 10 shows the second embodiment, and the basic configuration is the same as that of the first embodiment, except that the drive shaft 8 and the driven shaft 9 are each of the first embodiment as indicated by arrows in the drawing. It rotates in the opposite direction to the embodiment.
That is, in this structure, the oil O collected in the collecting grooves 32, 32 is pushed out upward in the direction of gravity by the rotational force.

  In this embodiment, as shown in FIGS. 10 and 11, interference walls 35 and 35 are provided on both side edges of the upper wall 29, respectively. The interference walls 35 and 35 extend substantially linearly from both side edges of the upper wall 29 and are disposed so as to cover the upper portions of the oil discharge holes 31 and 31, respectively. Further, the length of each interference wall 35, 35 in the front-rear direction in the figure is slightly longer than the width length W1 of each oil discharge hole 31, 31.

  Further, guide surfaces 36 and 36 having substantially circular arc sections are formed on the lower surfaces of the interference walls 35 and 35, respectively. The guide surfaces 36 are formed over the entire front and rear direction of the interference walls 35 in the drawing.

  Therefore, according to this embodiment, the oil O pushed out from the collecting grooves 32 and 32 in the gravity direction as the counterweights 26 and 27 rotate is guided to the interference walls 35 and 35. While interfering with the surfaces 36, 36, the direction is changed in a folded shape, and the oil is guided in the directions of the oil discharge holes 31, 31. As a result, the oil is efficiently discharged from the oil discharge holes 31, 31 into the oil pan 4.

  Further, since the lengths of the interference walls 35, 35 and the guide surfaces 36, 36 in the front-rear direction in the drawing are formed to be longer than the width length W1 of the oil discharge holes 31, 31, As the counterweights 26 and 27 rotate, the oil O pushed out from the collecting grooves 32 and 32 upward in the gravitational direction more reliably interferes with the guide surfaces 36 and 36 of the interference walls 35 and 35. It is guided in the direction of the oil discharge holes 31, 31 and is discharged from here into the oil pan 4.

  As described above, since the oil O in the weight chamber 30 can be effectively discharged by the guiding action of the interference walls 35 and 35 and the guide surfaces 36 and 36, both the shafts 8 and 9 are different from the first embodiment. Even in the case of rotating in the reverse direction, the same effects as those of the first embodiment can be obtained.

  The present invention is not limited to the configuration of each of the embodiments described above, and the configuration can be changed without departing from the spirit of the invention.

  For example, the balancer device 6 is also applicable to a shaft in which the outer diameters and lengths of the shafts 8 and 9 and the sizes of the counterweights 26 and 27 are variously changed depending on the displacement and size of the internal combustion engine. it can.

  In each embodiment, a so-called crankcase-integrated balancer device provided integrally with the lower portion of the crankcase 3 is used. However, the present invention is also applicable to a balancer device in which a housing is formed separately from the crankcase. Can do.

  Further, in each of the above embodiments, the counterweights 26 and 27 have been described using semi-cylindrical ones. However, for example, those having a substantially fan-shaped cross section may be used.

3 ... Crankcase 4 ... Oil pan 6 ... Balancer device 7 ... Housing 8 ... Drive shaft (drive-side balancer shaft)
9 ... Driven shaft (driven balancer shaft)
DESCRIPTION OF SYMBOLS 10 ... Drive side gear 11 ... Drive side gear 12 ... Housing main body 13 ... Cover part 26 ... Drive side counterweight (balancer weight)
26a ... Flat part 27 ... Follower side weight (balancer weight)
27a ... Flat portion 28 ... Lower wall 29 ... Upper wall 30 ... Weight chamber 31 ... Oil discharge hole (opening)
32 ... Collection groove 33 ... Collection taper surface 33a ... Base end edge 33b ... Tip edge 34 ... Side wall surface 35 ... Interference wall 36 ... Guide surface

Claims (9)

A housing attached to the internal combustion engine;
A balancer shaft rotatably accommodated in the housing;
A balancer weight projecting radially from the outer peripheral surface of the balancer shaft, and having a flat portion on the rotational direction side of the balancer shaft;
An opening portion provided at a position facing the flat surface portion at a predetermined rotational position of the balancer weight of the housing, and communicating with the inside and outside of the housing;
With
A collecting taper surface inclined downward from a base end edge of the balancer weight in the vicinity of the balancer shaft toward a distal end edge in the radial direction, and a vertical rising from both side edges of the collecting taper surface. A balancer device for an internal combustion engine, characterized in that a collecting groove comprising both side wall surfaces is provided. The balancer device for an internal combustion engine according to claim 1,
An extension line in the radial direction of the balancer weight on the collecting taper surface is formed so as to pass through the axial center of the balancer shaft or through a position opposite to the balancer weight with respect to the axial center of the balancer shaft. A balancer device for an internal combustion engine. The balancer device for an internal combustion engine according to claim 2,
A balancer device for an internal combustion engine, characterized in that the width of the collection groove in the axial direction of the balancer weight is gradually increased from the base end edge toward the tip end edge. The balancer device for an internal combustion engine according to claim 3,
A balancer device for an internal combustion engine, wherein the width of the opening in the axial direction of the balancer shaft is made larger than the width of the collecting groove in the axial direction. The balancer device for an internal combustion engine according to claim 4,
The balancer shaft is composed of a drive-side balancer shaft and a driven-side balancer shaft that are arranged in parallel in the housing, and each balancer shaft is provided with the balancer weight, and the opening is formed in the housing 2. A balancer device for an internal combustion engine, wherein two balancer weights are provided at positions facing the flat surface portion at a predetermined rotational position. The balancer device for an internal combustion engine according to claim 5,
The housing is provided with an interference wall that extends substantially linearly from the upper edge of the opening in the direction of gravity and covers the upper side of the opening in the direction of gravity, and the lower surface of the interference wall in the direction of gravity is provided. A balancer device for an internal combustion engine, wherein the balancer device is inclined downward toward the opening. The balancer device for an internal combustion engine according to claim 1,
The balancer device for an internal combustion engine, wherein the housing is housed in an oil pan for storing oil to be circulated inside the internal combustion engine. The balancer device for an internal combustion engine according to claim 7,
A balancer device for an internal combustion engine, wherein the opening is provided at a position higher than an oil level in an oil pan. A housing attached to the internal combustion engine;
A balancer shaft rotatably accommodated in the housing;
A balancer weight projecting radially from the outer peripheral surface of the balancer shaft, and having a flat portion on the rotational direction side of the balancer shaft;
An opening portion provided at a position facing the flat surface portion at a predetermined rotational position of the balancer weight of the housing, and communicating with the inside and outside of the housing;
With
Both side walls rising substantially vertically are provided on both side edges in the axial direction of the balancer shaft of the flat portion, and the both side walls are formed from the vicinity of the balancer shaft to the tip edge in the balancer weight radial direction. A balancer device for an internal combustion engine.

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