JP2014095329A - Timing train cover structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce film face vibration generated around an insertion hole formed on a face portion of a timing train cover structure to insert a rotating shaft, in the timing train cover structure covering a timing transmission mechanism of an internal combustion engine and fixed to one side of the engine body.SOLUTION: A group of reinforcement ribs R composed of a plurality of tangential ribs 40 disposed along the tangential direction of an insertion hole 34 while intersected with each other, is disposed around the insertion hole 34 formed on a face portion 32 of a timing train cover C to insert a crank shaft 6.

Description

  The present invention relates to a timing train cover structure that is provided on one side of an engine body of an internal combustion engine and covers a timing transmission mechanism of the internal combustion engine, and in particular, to increase rigidity around an insertion hole through which a rotating shaft is inserted. It relates to what was made.

  Conventionally, in a four-cycle internal combustion engine, a crankshaft and a valve camshaft for operating a valve gear are linked and connected via a timing transmission mechanism, and the rotation of the crankshaft is operated with a reduction ratio of 1/2. The timing transmission mechanism is covered with a timing train cover provided on one side of the engine body of the internal combustion engine.

  By the way, a rotating shaft such as a crankshaft is inserted into the timing train cover, and the rotational vibration of the rotating shaft propagates as a membrane vibration to the cover surface of the timing train cover to generate a radiated sound, which is a vibration noise. There is a problem of causing it.

  Therefore, technical means for attenuating such membrane vibrations to reduce vibration noise are already known. For example, in Patent Document 1 described later, a cylinder of an engine body is provided on an inner surface of a gear case covering a timing train. A plurality of radial ribs are provided from the vibration attenuating bolts fixed to the block to the mounting bolt insertion portion of the gear case to suppress the membrane vibration and reduce the vibration noise accompanying the driving of the internal combustion engine.

  However, the thing of the said patent document 1 has the subject that the area of each area | region divided by the radial rib is large, and the reduction effect of a membrane vibration is not enough, In order to solve this subject, increasing the number of radial ribs, Although it is conceivable to increase the wall thickness, there is another problem that the timing train cover itself increases in weight and costs accordingly.

Utility Model Registration No. 2526040

  The present invention has been made in view of such circumstances, and the periphery of the insertion hole is finely divided by a specific reinforcing rib group provided around the insertion hole of the rotating shaft of the timing train cover, and the periphery thereof is formed. It is an object of the present invention to provide a novel timing train cover structure that can significantly reduce generated membrane vibrations and solve the above problems.

To achieve the above object, the invention of claim 1 is a timing train cover structure that is fixed to one side of an engine body of an internal combustion engine and covers a timing transmission mechanism of the internal combustion engine,
A peripheral portion having a plurality of fastening portions fastened to the engine body, and a plate-like surface portion covering the timing transmission mechanism, connecting the peripheral portion;
An insertion hole through which the rotation shaft is inserted is opened in the surface portion, and the periphery of the insertion hole is formed thicker than the surface portion, and surrounds the insertion hole, either the inner surface or the outer surface of the surface portion. On one side, a reinforcing rib group is provided integrally,
The reinforcing rib group is composed of a plurality of linear tangential ribs that are provided tangentially in the tangential direction of the insertion hole with a space in the circumferential direction of the insertion hole. It is characterized by overlapping with the boss around the hole and forming a part of the boss.

  In order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the present invention, the plurality of linear tangential ribs are provided symmetrically with respect to the center of the insertion hole and intersect each other. It is characterized by comprising a plurality of pairs of tangential ribs.

  In order to achieve the above object, the invention of claim 3 is characterized in that, in the invention of claim 2, the pair of tangential ribs are provided at predetermined equal angles over the entire circumference of the insertion hole. Yes.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the first, second, or third aspect, at least a part of the plurality of straight tangential ribs is connected to the fastening portion. It is a feature.

  To achieve the above object, according to a fifth aspect of the present invention, in the first, second, third, or fourth aspect, the surface portion surrounds the insertion hole and intersects the plurality of linear tangential ribs. An annular rib is provided.

  To achieve the above object, the invention according to claim 6 is the invention according to claim 5, wherein the annular rib is an intersection of the tangential ribs intersecting each other among the plurality of linear tangential ribs. It is characterized by crossing.

  To achieve the above object, the invention according to claim 7 is the invention according to claim 5 or 6, wherein the plurality of linear tangential ribs and the annular rib are provided on an inner surface of the surface portion. A plurality of extending portions whose free ends come into contact with the internal combustion engine body are provided, and at least a part of the extending portions is provided on the annular rib.

  According to the invention of each claim, the periphery of the high-rigidity insertion hole through which the rotating shaft of the timing train cover is inserted is finely divided by the reinforcing rib group, and the surface portion having low rigidity is concentrated in the surrounding area. Reinforcement, and the reinforcement ribs are in line contact with the highly rigid insertion holes, reinforcing the surroundings of the insertion holes without increasing the number of ribs, effectively preventing membrane vibration generated around the insertion holes In addition, the weight increase due to the reinforcing rib group can be suppressed.

  According to the second and third aspects of the present invention, the plurality of linear tangential ribs are provided symmetrically with respect to the center of the insertion hole, and therefore the rigidity around the insertion hole is evenly increased. Thus, the membrane vibration generated around the insertion hole can be more effectively reduced.

  According to the invention of claim 4, one end of the other end of the linear tangential rib is connected to the highly rigid insertion hole, and the other end is connected to the highly rigid fastening portion, so that the rigidity of the rib is remarkably increased. Further, the rigidity of other ribs intersecting the rib can be improved, and the vibration reducing effect of the timing train cover is further enhanced.

  Further, according to the inventions of claims 5 and 6, the annular rib divides the linear tangential rib in the longitudinal direction, so that the surface portion becomes finer, and the linear tangential ribs are circumferentially arranged by the annular rib. It is possible to connect, the rigidity around the insertion hole is further increased, and the membrane vibration generated around the insertion hole can be more effectively reduced.

  According to the seventh aspect of the present invention, the inner surface of the surface portion of the timing train cover is provided with an extending portion whose free end is in contact with the internal combustion engine body, and the extending portion is provided on the annular rib. The rigidity of the surface portion is increased and the rigidity of the annular rib is also increased, so that the effect of reducing the membrane vibration generated around the insertion hole can be further enhanced.

End view of the engine body as seen from the crankshaft direction of the internal combustion engine having the timing train cover structure of the present invention Partially cutaway side view of the engine body along line 2-2 in FIG. A partial enlarged view of the timing train cover as viewed from the inside along the line 3-3 in FIG. Enlarged cross-sectional view along line 4-4 in FIG. Schematic diagram of reinforcing rib group

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

  In this embodiment, the timing train cover structure of the present invention is applied to an OHV type four-cycle multi-cylinder internal combustion engine E for automobiles.

  In the following description, the vertical direction, the horizontal direction, and the inner and outer directions are based on the engine body 1 in FIG.

  As shown in FIGS. 1 and 2, an engine main body 1 constituting a main part of the internal combustion engine E includes a cylinder block 2 in which a plurality of cylinders each having a piston 13 slidably fitted thereto are arranged in series, and the cylinder block 2 is provided with a cylinder head 3 fixed on the deck surface and provided with a valve operating device V. A head cover 4 is fixed on the upper surface of the cylinder head 3, and an oil pan 5 is mounted on the lower surface of the crankcase portion below the cylinder block 2. Is connected. The crankshaft 6 is rotatably supported by the crankcase portion and a bearing cap 16 fixed to the lower surface of the crankcase portion. The cylinder head 3 is rotatably supported by a pair of valve cam shafts 7 and 7 for driving the valve operating device V. The valve operating device V is covered by the head cover 4.

  The crankshaft 6 and the valve camshafts 7 and 7 are linked and connected by a timing transmission mechanism T. The timing transmission mechanism T includes a drive sprocket 8 fixed to the outer end of the crankshaft 6, a dual idle sprocket 11 rotatably supported on the cylinder block 2, and an outer end of the valve valve camshaft 7 on the intake side. A driven sprocket 9 fixed to the drive end 8, an endless chain 12 suspended between one of the drive sprocket 8 and the dual idle sprocket, and an endless chain suspended between the other of the dual idle sprocket 11 and the driven sprocket 9. The rotation of the crankshaft 6 is transmitted to the valve camshafts 7 and 7 through the timing transmission mechanism T with a 1/2 reduction ratio.

  The intake camshaft 7 and the exhaust camshaft 7 'are gear-connected, and the dual idle sprocket 11 is for driving a fuel pump (not shown).

  The timing transmission mechanism T is provided outside one side surface (a surface orthogonal to the crankshaft 6) of the engine body 1, and is covered by a timing train cover C fixed to the one side surface.

  The timing train cover C is made of metal, and is fixed to one side surface of the cylinder block 2 and the cylinder head 3 across the mating surfaces.

  The timing train cover C has a peripheral portion 30 provided with a plurality of fastening portions 31 fixed to the engine main body 1, and the peripheral portion 30. The timing train cover C is substantially parallel to one side surface of the engine main body, and includes the timing transmission mechanism T. The peripheral edge 30 is a portion that is bent from the surface 32 toward the engine main body 1 side, and the plurality of fastening portions 31 are boss holes through which the connecting bolts 15 are inserted. Is formed, and is fastened to one side of the engine body 1 with a connecting bolt 15 inserted through the boss hole.

  In the lower portion of the surface portion 32 of the timing train cover C, an insertion hole 34 having a perfect circle shape through which one end portion of the crankshaft 6 is inserted is opened. The insertion hole 34 is a boss hole, and the outer peripheral portion thereof is formed with a predetermined width in the radial direction on the entire circumference of the insertion hole 34, and is thicker than the surface portion 32 of the timing train cover C. An oil seal 35 is provided between the inner peripheral surface of the insertion hole 34 and the outer peripheral surface of the crankshaft 6 so as to oil-tightly seal between them.

  As shown in FIG. 3, the periphery of the insertion hole 34 is reinforced by a reinforcing rib group R that is integrally formed on the inner side surface of the surface portion 32 to increase the rigidity.

  The starting force generated when the chains 12 and 10 of the timing transmission mechanism T are operated causes the timing train cover C to vibrate due to air propagation and the like, and the timing train cover C itself generates noise. The resonance rib group R can prevent the resonance by raising the natural frequency of the timing train cover C from the normal range.

  The membrane vibration generated around the insertion hole 34 due to the rotational vibration of the crankshaft 6 is reduced.

  Next, a specific structure of the reinforcing rib group R will be described.

  As shown in FIGS. 3 and 5, the reinforcing rib group R includes a plurality of pairs of straight lines extending around the tangential direction around the insertion hole 34 made of a boss hole and extending in the tangential direction. In addition to the linear tangential rib 40, the surface portion 32 is provided with an annular annular rib 50 surrounding the outer periphery of the insertion hole 34 with a space.

The plurality of pairs of linear tangent ribs 40 are shown in FIGS.
Twelve first to twelfth tangential rib pairs A, each including two tangential ribs Aa and A2 extending in a tangential direction of the insertion hole 34 and having a narrow angle of about 90 °, are arranged on the outer periphery of the insertion hole 34. The tangential rib pairs A are formed on the outside of the insertion hole 34 so as to be formed at substantially equal intervals along the surface.

  Twelve pairs of first to twelfth tangential ribs B, which are formed of two tangential ribs Ba, B2 extending in a tangential direction of the insertion hole 34 and having an included angle of approximately 30 °, are inserted into the insertion hole 34. The first to twelfth tangent rib pairs A ... and the first to twelfth tangent rib pairs B intersect with the radiation passing through the center of the insertion hole 34 at substantially equal intervals. The intersection of the first to twelfth tangential rib pairs B intersects outside the first to twelfth tangent rib pairs A. And although the intersection of the 1st-12th tangent rib pair B is connected with the surface part 32, the part is connected with the surface part 32 before the intersection.

  The first to twelfth tangential rib pairs A ... and the first to twelfth tangential rib pairs B are provided symmetrically with respect to the center CE of the insertion hole 34 and intersect each other. , They also intersect with the annular rib 50.

  Further, as shown in FIG. 3, extending portions 51, 52, and 53 made of three bosses are integrally protruded inwardly on the inner side surface of the surface portion 32, of which extending portions The portions 31 and 52 intersect the annular rib 50, and the extending portion 53 is biased to one side of the annular rib 50. As shown in FIG. 4, when the timing train cover C is fixed to the internal combustion engine body 1, the free ends of these extending portions 51, 52, 53 are brought into contact with one side surface of the internal combustion engine body 1. The fixing strength of the plate-like surface portion 32 of the timing train cover C with respect to the engine body 1 is increased and its membrane vibration is suppressed.

  Furthermore, a plurality of reinforcing seats 54 are provided inwardly on the inner side surface of the surface portion 32 around the insertion hole 34 and outside the annular rib 50 to reinforce the plate-like surface portion 32.

  The reinforcing seats 54 are extrusion seats that are used when the timing train cover C is extruded from the mold, and are pedestals that push out the timing train cover C that is a product by pushing with a pin from the mold side when releasing the mold. Yes, because it is thick, it is rigid and has a reinforcing effect.

  The reinforcing seats 54 are arranged at equal intervals in the circumferential direction around the insertion hole 34.

  The timing train cover C configured as described above has its inner surface abutted against one side surface of the engine body 1 composed of the cylinder block 2 and the cylinder head 3, and a plurality of fastening portions 31 provided on the peripheral portion 30. The timing train cover C is integrally attached to one side of the engine body 1 by inserting the connecting bolts 15 into the respective boss holes and fastening them to the engine body 1.

  When the crankshaft 6 is rotated by the operation of the internal combustion engine E and the timing transmission mechanism T is operated, the rotation and the operating vibration are transmitted to the timing train cover C through the oil seal 35 and the insertion hole 34. The

  By the way, the insertion hole 34 itself made of the boss hole has high rigidity, whereas the surface portion 32 around the boss hole has low rigidity, and thus vibration is generated. For this reason, the reinforcing rib group R can finely divide the periphery of the insertion hole 34 made of the boss hole with high rigidity, and the linear tangential rib can be connected to the boss hole with high rigidity so as to surround the insertion hole 34. Therefore, it is possible to effectively reduce the generation of noise caused by the vibration while suppressing an increase in weight.

  Further, the plurality of tangential rib pairs A and B constituting the straight tangential rib 40 are provided symmetrically with respect to the center of the insertion hole 34, and the plurality of tangential rib pairs A and B intersecting each other are inserted. By providing the entire circumference of the circumference of the hole 34 at every predetermined angle, the circumference of the insertion hole can be uniformly reinforced over the entire circumference, and a film generated around the insertion hole 34 while suppressing an increase in weight. The effect of reducing vibration can be further enhanced.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to that embodiment, Various other embodiment is possible within the scope of the present invention.

  For example, in the above-described embodiment, the case where the reinforcing rib group is formed on the inner side surface of the surface portion of the timing train cover has been described. However, the reinforcing rib group may be formed on the outer surface of the surface portion of the timing train cover. In the above embodiment, the case where the reinforcing rib group according to the present invention is provided around the insertion hole through which the crankshaft is inserted, which is opened in the timing train cover, is described. The reinforcing rib group according to the present invention may be provided around an insertion hole through which the valve cam shaft and other rotating shaft are inserted.

1 .... Engine body 7 ..... Rotary shaft (Crankshaft)
3 ..... Cylinder head 30 .... Peripheral part 31 .... Fastening part 32 ..... Surface part 34 ..... Insertion hole 50 ········· Ring 51 ·················································································· Tangential rib pair B ... Tangential rib pair C ... Timing train cover CE ... Center of insertion hole 34 T ... Transmission mechanism

Claims (7)

A timing train cover structure fixed to one side of the engine body (1) of the internal combustion engine (E) and covering the timing transmission mechanism (T) of the internal combustion engine (E);
A peripheral part (30) having a plurality of fastening parts (31) fastened to the engine body (1), and a plate-like surface part (32) covering the timing transmission mechanism (T) by connecting the peripheral part (30). )
The surface portion (32) has an insertion hole (34) through which the rotation shaft (7) is inserted, and the periphery of the insertion hole (34) is formed thicker than the surface portion (32). A reinforcing rib group (R) is integrally provided on either the inner side surface or the outer side surface of the surface portion (32) surrounding the hole (34),
The reinforcing rib group (R) has a plurality of linear tangential ribs (40) provided in a tangential direction in the tangential direction of the insertion hole (34) with a space in the circumferential direction of the insertion hole (34). The internal combustion engine timing train cover structure, characterized in that the linear tangential rib (40) overlaps with and forms a part of the boss portion around the insertion hole (34). .   The plurality of linear tangential ribs (40) are formed of a plurality of pairs of tangential ribs (A, B) provided symmetrically with respect to the center (CE) of the insertion hole (34) and intersecting each other. The timing train cover structure for an internal combustion engine according to claim 1, wherein:   The timing train for an internal combustion engine according to claim 2, wherein the tangential rib pairs (A, B) are provided at predetermined equal angles over the entire circumference of the insertion hole (34). Cover structure.   4. The internal combustion engine timing train according to claim 1, wherein at least a part of the plurality of straight tangential ribs is connected to the fastening portion. Cover structure.   The said surface part (32) is provided with the annular rib (50) which surrounds the circumference | surroundings of the said insertion hole (34), and cross | intersects these linear tangent ribs (40), The said Claim 1 characterized by the above-mentioned. , 23 or 4, the timing train cover structure for an internal combustion engine.   The said annular rib (50) cross | intersects this tangent rib at the intersection of the tangent rib which mutually cross | intersects among the said multiple linear tangent ribs (40), The said Claim 5 characterized by the above-mentioned. Timing train cover structure for internal combustion engine.   The plurality of linear tangential ribs (40) and the annular rib (50) are provided on an inner surface of the surface portion (32), and a free end abuts on the inner surface of the internal combustion engine body (1). A plurality of extending portions (51, 52, 53) are provided, and at least a part of the extending portions (51, 52, 53) is provided on the annular rib (50). The timing train cover structure for an internal combustion engine according to claim 5 or 6.

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