JP2014009799A - Balancer for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balancer for an internal combustion engine capable of restraining air bubbles from being mixed into oil discharged from a housing to an oil pan.SOLUTION: A lower housing 12 of the balancer 10, which is housed in an oil pan and houses a pair of balancer shafts, a drive shaft 13 and a driven shaft 14 in parallel, has second discharge holes 32a,32b provided vertically below axial centers of the shafts 13, 14 for discharging oil and side walls 33a, 33b provided opposed to openings of the second discharge holes 32a,32b so that the oil discharged from the second discharge holes 32a, 32b collides with them.

Description

  The present invention relates to a balancer device for an internal combustion engine applied to, for example, an automobile.

  As a conventional balancer device for an internal combustion engine applied to an automobile, for example, the one described in Patent Document 1 below is known.

  Briefly, this balancer device is accommodated in an oil pan disposed below the cylinder block of the engine, and a housing that is bolted to the lower portion of the cylinder block, And a pair of balancer shafts arranged in parallel.

  The balancer device is disposed at a position where the balancer is substantially immersed in the oil in the oil pan. By taking the oil in the oil pan into the housing, the balancer shaft performs bearing lubrication and the like. It has become.

  However, the oil taken into the housing particularly stays in the accommodation space of the balance weight portion of each balancer shaft, and causes a disadvantage that the balance weight portion rotates.

  Accordingly, in the balancer device, predetermined opening portions are provided at the upper and lower portions of the housing space of each balance weight portion in the housing, so that each balance weight is flipped up by the balance weight when the balance weight is rotated (engine operation). It is possible to drain the oil that has flowed into the storage space from the upper opening and from the lower opening when each balance weight is stationary (when the engine is stopped). I have to.

JP 2008-175137 A

  However, the conventional balancer device is configured such that the oil discharged from each opening directly collides with the oil surface of the oil stored in the oil pan. There is a problem that air (bubbles) is mixed into the oil stored in the inside.

  The present invention was devised in view of the situation of the conventional balancer device for an internal combustion engine, and provides a balancer device for an internal combustion engine that can suppress the mixing of bubbles in oil discharged to an oil pan. It is aimed.

  The present invention enables the oil to be discharged from a position vertically below the axis of each balancer shaft, with respect to the housing of the balancer device that is housed in the oil pan and in which a pair of balancer shafts are housed in parallel. And an suppressing portion provided so that the oil discharged from the opening hits.

  As a specific form, the opening is provided in such a manner that at least a part of the opening is opened vertically below the axis of each balancer shaft, and the suppressing portion is provided outside the opening. It is desirable to use a wall portion extending vertically downward on the side and facing the opening.

  According to the present invention, it is possible to attenuate the momentum of the oil flowing out by colliding the oil flowing out from the opening portion with the restraining portion (wall portion), and the oil that has flowed out is contained in the oil pan. There is no risk of directly colliding with the oil level. Thereby, mixing of the bubble about the oil discharged | emitted to the oil pan can be suppressed.

  In addition, by configuring the suppression portion as a wall portion as described above, it is also possible to suppress inconvenience that the oil scattered by the oil surface in the oil pan undulates into the device through the opening. Provided.

It is a perspective view showing the appearance of the whole balancer device concerning the present invention. It is a principal part expanded sectional view of the upper surface side of the balancer apparatus showing the structure of the upper opening part shown in FIG. It is the arrow view seen from the A direction of FIG. It is a longitudinal cross-sectional view which follows the BB line of FIG. FIG. 3 is an enlarged view of a main part on the apparatus lower surface side of the balancer showing a three-dimensional shape in the vicinity of the opening shown in FIG. 2.

  Hereinafter, an embodiment in which a balancer device for an internal combustion engine according to the present invention is applied to an automobile engine will be described with reference to the drawings.

  That is, as shown in FIGS. 1 and 2, the balancer device 10 is formed in a substantially halved shape, and is connected to each other by a plurality of bolts 30 (see FIGS. 3 and 4) to form one housing. An upper housing 11 and a lower housing 12 that constitute the balancer, and a balancer that is disposed between the housings 11 and 12 in parallel in the front-rear direction of the engine (the Y-axis direction in FIGS. 1 and 3, etc.) and is rotatably supported. The drive-side drive shaft 13 and the driven-side driven shaft 14 which are shafts, and the tooth portions 15a formed on the respective outer peripheral portions are fixed to the axial intermediate portion of the drive shaft 13 and one axial end portion of the driven shaft 14, respectively. , 16a meshes with each other, and a drive side gear 15 and a driven side gear 16 that rotate in reverse to each other are provided.

  The balancer device 10 is bolted to a ladder frame (not shown) attached to the lower part of the cylinder block of the engine mainly through a plurality of bolt fastening portions 11a provided in the upper housing 11, and fitted to the outside thereof. In this way, it is accommodated in an oil pan (not shown) that is fixedly attached to the ladder frame.

  The drive shaft 13 includes first to third bearing portions 21 to 23 disposed between the housings 11 and 12 via journal portions (not shown) provided at both axial end portions and intermediate portions thereof. The shaft portion between the journal portions supported by the first and second bearing portions 21 and 22 is rotatably supported by the shaft portion around the shaft portion. A balance weight 13a which is a balance portion is integrally formed over the axial direction. The drive shaft 13 rotates based on a driving force transmitted from a crankshaft (not shown), and rotates twice for each rotation of the crankshaft.

  On the other hand, the driven shaft 14 has an axial length that is about 2/3 shorter than that of the drive shaft 13, and the driven shaft 14 also has journal portions ( Between the journal portions supported by the first and second bearing portions 24 and 25 and supported by the first and second bearing portions 24 and 25. A balance weight 14a having the same mass as the balance weight 13a of the drive shaft 13 is integrally formed on the shaft portion. The driven shaft 40 rotates reversely with respect to the drive shaft 13 based on the driving force input to the drive shaft 13, thereby exhibiting a vibration damping action that cancels the secondary vibration of the engine.

  As shown in FIGS. 1 and 2, the upper housing 11 is formed with a series of gear housing portions 26 for swelling the gears 15 and 16 in the Y-axis direction intermediate portion, A series of weight accommodating portions 27 for accommodating the balance weights 13a and 14a is provided at one end side in the Y-axis direction (the front side in the drawing) from the gear accommodating portion 26. One end side in the Y-axis direction of the upper housing 11 Bulges over the region.

  Of the weight accommodating portions 27, the X-axis direction both ends of the upper walls 27 a and 27 b configured in a thin curved shape not used for mounting the upper housing 11 respectively flow into the weight accommodating portion 27. The first discharge holes 31a and 31b are formed to penetrate the discharged oil. Specifically, each of the first discharge holes 31a and 31b is formed by cutting both end portions of the upper walls 27a and 27b, and the balance weights 13a and 14a are rotated, The oil that has flowed into the weight accommodating portion 27 is discharged so as to be scraped off.

  As with the upper housing 11, the lower housing 12, particularly as shown in FIGS. 2 to 5, has a single gear housing that is configured in a manner corresponding to the gear housing portion 26 in the intermediate portion in the Y-axis direction. The portion 28 is formed in a bulging manner, and a series of weight accommodating portions configured to correspond to the weight accommodating portion 27 on one end side (the front side in the drawing) of the Y axis direction with respect to the gear accommodating portion 28. 29 is formed to bulge over a region of the lower housing 12 on one end side in the Y-axis direction.

  The lower housing 12 also has second discharge holes 32a and 32b (in accordance with the present invention) for discharging oil that has flowed into the weight housing portion 29 at both ends in the X-axis direction of the weight housing portion 29, respectively. (Corresponding to the opening) is formed through substantially the entire length of the weight accommodating portion 29 in the longitudinal direction. Each of the second discharge holes 32a and 32b is provided so as to open to the side of the lower housing 12 at both ends of the pair of bulged portions 29a and 29b formed in a curved shape, and the vertical As shown in FIG. 4 in particular, the lower end position is a position vertically below the shaft center of each of the shafts 13 and 14, and from the oil level position in the oil pan during engine operation (dashed line L1 shown in FIG. 4). It is set to be higher (vertical upper position) than the oil level position (broken line L0 shown in FIG. 4) in the oil pan when the engine is stopped. With this configuration, the oil flowing into the weight accommodating portion 27 can be discharged through the second discharge holes 32a and 32b, and the oil pan can be used not only during engine operation but also when the engine is stopped. The inconvenience that the oil inside flows into the lower housing 12 through the second discharge holes 32a and 32b (back flow) is avoided.

  Further, as shown in FIGS. 3 and 5, both outer end portions of the lower housing 12 are configured to connect the bolt fastening portions 12 a and 12 a formed in a substantially cylindrical shape in the Y-axis direction. A pair of side walls 33 a and 33 b (corresponding to a wall portion (suppressing portion) according to the present invention) are provided integrally with the lower housing 12. As described above, the side walls 33a and 33b function as so-called reinforcing ribs by connecting the bolt fastening portions 12a and 12a so that the rigidity of the housing 12 is improved. ing. Moreover, by forming integrally with the lower housing 12, favorable productivity of the housing 12 can be secured, and the cost of the apparatus 10 is also reduced.

  The side walls 33a and 33b extend vertically downward so as to face the second discharge holes 32a and 32b and interfere with the discharged oil. At this time, as shown in FIG. 4, the side walls 33a and 33b extend to the vertical positions where the tips (lower ends) reach the oil level L0 in the oil pan when the engine is stopped. Thus, the opening area with respect to the oil surface L0 and the opening angle range around the Y axis are limited.

  Further, as shown in FIGS. 3 and 5, the bulging portions 29a and 29b of the lower housing 12 and the bulging portions 29a and 29b are arranged in the Y-axis direction intermediate portion. And ribs 34a to 34c are erected to connect the side walls 33 and 33b. That is, with the ribs 34a to 34c, the rigidity of the lower housing 12 is improved, and the second discharge holes 32a and 32b are divided into two parts so that the opening area with respect to the oil level L1 (L0) The opening angle range around the X axis is further limited.

  As described above, according to the balancer device according to the present embodiment, the side walls 33a and 33b that are close to and opposite to the second discharge holes 32a and 32b are provided, and the second discharge holes are provided in the side walls 33a and 33b. With the configuration in which the discharged oil from 32a and 32b collides, it becomes possible to attenuate the momentum of the discharged oil by the side walls 33a and 33b, and the discharged oil is oil in the oil pan. The inconvenience of directly colliding with the surface L1 (L0) is not caused. As a result, it is possible to suppress a problem that air (bubbles) is mixed into the oil discharged to the oil pan.

  In addition, at this time, the side walls 33a and 33b are extended so as to reach the oil level L0 when the engine is stopped, which is higher than the oil level L1 when the engine is operating. Even if L0 (L1) undulates, the scattered oil is almost blocked by the side walls 33a and 33b, and the backflow into the device 10 through the second discharge holes 32a and 32b is prevented. Also used for suppression.

  Further, since the plurality of the second discharge holes 32a and 32b are provided so as to cover almost the entire longitudinal direction of the weight accommodating portion 27, good discharge performance of the oil in the apparatus 10 is ensured. In addition, since each of the second discharge holes 32a and 32b is divided, the expansion of the oil at the time of the oil discharge is also suppressed by the reduction of the opening of each of the discharge holes 31 and 32. Can be more effectively suppressed. In other words, the ribs 34b and 34c enable the attenuation to the oil scattered in the Y-axis direction in FIG. 3, and the air mixing can be effectively suppressed.

  Further, in the case of each of the second discharge holes 32a and 32b, the second exhaust holes 32a and 32b are provided at a position higher than the oil level L1 in the oil pan during the most frequently used engine operation, that is, provided at a position at which oil is more difficult to flow. The opening area of each of the second discharge holes 32a and 32b can be set larger, which is also used for improving the oil discharge efficiency.

  The present invention is not limited to the configuration of the above-described embodiment. For example, the present invention includes the specific configurations of the housings 11 and 12 and the shafts 13 and 14 that are not directly related to the features of the invention. As for the specific shapes of the second discharge holes 32a and 32b and the corresponding side walls 33a and 33b corresponding to the second exhaust holes 32a and 32b, the internal combustion engine to be applied or mounted as long as it has the above-described effects. Needless to say, it can be changed freely according to the specifications of the vehicle.

  In particular, the side walls 33a and 33b are not necessarily formed integrally with the lower housing 12, and may be configured as separate members that can be assembled from the outside with a predetermined locking means, for example. By adopting such a separate configuration, the shape of each side wall 33a, 33b can be freely set regardless of the molding die of the lower housing 12, and the damping action by each side wall 33a, 33b can be more effectively performed. Advantages that can be generated are obtained.

  In the present embodiment, the first and second discharge holes 32a and 32b are used in combination, but sufficient discharge performance can be ensured only by the second discharge holes 32a and 32b. In other words, by using the first and second discharge holes 32a and 32b in combination, more oil can be discharged, and the oil staying in the weight accommodating portion 25 can be discharged well.

  Hereinafter, technical ideas other than those described in the scope of claims understood from the embodiment will be described.

(A) In the internal combustion engine balancer device according to claim 1,
Each of the balancer shafts has an unbalanced portion for suppressing secondary vibration of the engine,
The balancer device for an internal combustion engine, wherein the opening is provided in a portion that accommodates each of the unbalanced portions.

  With this configuration, the oil can be discharged by the rotation of the unbalance portion.

(B) The balancer device for an internal combustion engine according to claim 1,
A balancer device for an internal combustion engine, wherein a plurality of the openings are provided in the axial direction of each balancer shaft.

  With this configuration, more oil can be discharged. Further, by dividing the opening into a plurality of portions, it is possible to reduce the opening of each opening, and thus it is also used to suppress the spread of oil when the oil is discharged.

(C) In the balancer device for an internal combustion engine according to claim 1,
The balancer device for an internal combustion engine, wherein the opening is provided at a position higher than an oil level in the oil pan during engine operation.

  In this way, by arranging the opening at a position where oil does not easily flow in during the most frequently used engine operation, the area of the opening can be set larger, and the oil discharge efficiency can be improved. it can.

(D) In the balancer device for an internal combustion engine according to claim 2,
The balancer device for an internal combustion engine, wherein the suppression portion is integrally provided outside the housing.

  With such an integrated configuration, the productivity of the housing can be improved, and the cost of the apparatus can be reduced.

(E) In the balancer device for an internal combustion engine according to claim 2,
The balancer device for an internal combustion engine, wherein the restraining portion is attached to the outside of the housing with a predetermined locking means.

  By adopting such a separate configuration, the shape of the suppressing portion can be freely set regardless of the molding die of the housing, and the damping action by the suppressing portion is more effectively generated.

(F) The balancer device for an internal combustion engine according to claim 2,
The suppression portion is provided outside the housing,
An axially extending portion extending in the axial direction of the balancer shaft;
An axially perpendicular extending portion extending in a direction perpendicular to the axis of the balancer shaft;
A balancer device for an internal combustion engine, comprising:

  By setting it as this structure, it can suppress also about the scattering of the oil which concerns on an axis perpendicular direction.

(G) In the internal combustion engine balancer device according to claim 1 or 2,
The balancer device for an internal combustion engine, wherein the housing has a second opening vertically above the axis of the balancer shaft.

  With this configuration, more oil can be discharged.

(H) In the balancer device for an internal combustion engine according to claim 1,
The housing is provided with a plurality of bolt fastening portions for engine mounting,
The balancer device for an internal combustion engine, wherein the wall portion is provided so as to connect at least two of the bolt fastening portions.

  Thus, by providing a wall part between bolt fastening parts, the said wall part will function as a reinforcement rib, and it uses for the rigidity improvement of a housing.

(I) The balancer device for an internal combustion engine according to claim 1,
The balancer device for an internal combustion engine, wherein the wall portion is provided so as to reach an oil level in the oil pan when the engine is stopped.

  By adopting such a configuration, it becomes possible to effectively suppress the inflow of oil from the opening due to the oil surface in the oil pan undulating.

10 ... balancer device 11 ... upper housing (housing)
12 ... Lower housing (housing)
13 ... Drive shaft (balancer shaft)
14 ... Driven shaft (balancer shaft)
32a, 32b ... second discharge hole (opening)
33a, 33b ... side wall (wall portion, suppression portion)

Claims (2)

A pair of balancer shafts that rotate based on rotational force transmitted from the crankshaft;
A housing that is housed in an oil pan that stores oil circulating inside the engine, and that houses both the balancer shafts;
With
The housing is
An opening that is provided so as to open at least partially at a position vertically below the axial center of each balancer shaft;
A wall extending vertically downward outside the opening and disposed opposite the opening; and
A balancer device for an internal combustion engine, comprising: A pair of balancer shafts that rotate based on rotational force transmitted from the crankshaft;
A housing that is housed in an oil pan that stores oil circulating inside the engine, and that houses both the balancer shafts;
With
The housing is
An opening that allows the oil to be discharged from a position vertically below the axis of each balancer shaft;
A restraining portion provided so that the oil discharged from the opening hits;
A balancer device for an internal combustion engine, comprising:

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