JP2008025768A - Surrounding wall for motion mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an effect of suppressing generation of vibration and noise caused by motion of a motion mechanism in regard to a surrounding wall 3 for the motion mechanism even with a shape easy to design and capable of suppressing weight increase. <P>SOLUTION: The surrounding wall 3 has a multiplicity of first protruding line parts 5 provided substantially in parallel with each other and protruding outward, and a multiplicity of second protruding line parts 6 provided substantially in parallel with other to cross the first protruding line parts 5 and protruding outward. In at least the first protruding line part 5, a cross sectional shape in a direction orthogonal to its longitudinal direction is formed into a shape curved like a partial arc. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an enclosure wall that covers a motion mechanism. Examples of the surrounding wall include a transmission case attached to an engine mounted on an automobile or the like, and a timing cover that covers a motion mechanism of a system that transmits power from a crankshaft to a camshaft in the engine.

  For example, in transmissions attached to engines such as automobiles, the transmission case is generally caused by periodic or non-periodic movement (vibration force) of the gear train inside it or other movement mechanisms. May vibrate.

  Conventionally, by providing ribs protruding outward, for example, in a lattice shape, on the outer surface of the wall portion constituting the transmission case, the rigidity of the transmission case is increased and the vibration of the transmission case caused by the vibration force is suppressed. (For example, refer to Patent Document 1).

  The rib is a solid protrusion provided on the outer surface of the wall of the transmission case, and its cross-sectional shape is a square or a tapered trapezoid. In addition, a large number of partitioned regions partitioned by providing the ribs in a lattice shape have almost the same shape and almost the same area. However, the inner surface of the wall portion of the transmission case is a flat surface having substantially no unevenness in substantially the entire region.

  In addition, the motion mechanism of the power transmission system consisting of a timing chain (or timing belt) attached to the front end side of a cylinder block of an engine of an automobile or the like and a plurality of gears around which the timing chain is wound is concealed from the outside by a timing cover. Has been. Since this timing cover may vibrate with the movement of the motion mechanism, for the purpose of suppressing the vibration of the timing cover, the wall portion constituting the timing cover protrudes to the inner surface side or the outer surface side. It has been considered to provide a large number of concave surface portions and convex surface portions that are depressed at random (see, for example, Patent Document 2).

The planar view shapes of the multiple concave surface portions and the surface portions of the convex surface portions are polygonal, but the areas may be the same as each other, but may be uneven.
Japanese Patent Laid-Open No. 4-113062 JP 2001-342845 A

  In the conventional example of Patent Document 1 above, the entire inner surface of the wall portion of the transmission case is a flat surface having no irregularities, and solid ribs are provided in a lattice shape only on the outer surface of the wall portion. The whole part is a vibrating membrane. However, if the area of a large number of partitioned areas defined by the ribs is reduced, the rigidity of the wall portion of the transmission case can be improved and the effect of vibration suppression can be exhibited. Forced to increase significantly. In particular, it can be said that the larger the size of the transmission case, the more disadvantageous it is.

  For this reason, it is considered that it is difficult to adapt to the tendency to increase the weight of the transmission from the viewpoint of weight reduction as in recent years, which is not preferable. Moreover, if the increase in weight is limited, it can be said that the effect of suppressing vibration is naturally reduced. There is room for improvement in this respect.

  On the other hand, in the conventional example of Patent Document 2 described above, since a wide range of planes can be eliminated by providing a large number of concave surface portions and convex surface portions on the timing cover, the vibration suppressing effect is greater than that of the conventional example of Patent Document 1. It is believed that there is. However, it can be said that it is difficult to design the arrangement pattern due to the relationship in which the concave surface portions and the convex surface portions are randomly arranged, and there is a concern that the manufacturing cost increases.

  By the way, the transmission case like the conventional example of the above-mentioned Patent Document 1 is usually manufactured by casting using an aluminum alloy or the like as a material. In that case, the inner surface of the wall portion is not a bumpy surface but is a flat surface. There is no hindrance to the work of removing the molding die (core) for forming the inner space.

  Temporarily, when a concave flat part and a convex flat part as shown in the conventional example of Patent Document 2 are provided on the wall part of the transmission case so as to be randomly arranged, the inner surface of the wall part becomes a random concave / convex surface. Therefore, it becomes impossible to remove the molding die (core). That is, the concave surface portion and the convex surface portion as shown in the conventional example of Patent Document 2 are manufactured by a molding method in which, for example, two molding dies are brought into contact with each other with respect to the outer shape of the wall portion to be formed. Although it is advantageous only in such a case, it is impossible to manufacture when it is necessary to consider the removal of the molding die (core) as described above.

  In view of such circumstances, the present invention suppresses the generation of vibration and noise due to the motion of the motion mechanism, while the shape of the surrounding wall covering the motion mechanism is easy to design and can suppress an increase in weight. The purpose is to increase the effect.

  The present invention is an enclosing wall that covers the motion mechanism, and is provided substantially parallel to each other so as to cross a plurality of first protrusions that protrude outward and to cross the first protrusions. And a plurality of second protrusions protruding outward, and at least the first protrusion has a shape in which a cross section in a direction perpendicular to the longitudinal direction is curved in a partial arc shape. It is characterized by.

  According to this configuration, since the surrounding wall becomes uneven due to the curved first protrusion, the surrounding wall has a wide surface as compared with the conventional example in which the inner surface of the surrounding wall is made to be a flat surface over a wide area. Increased rigidity is possible.

  In addition, since the dimension in the direction perpendicular to the longitudinal direction, that is, the width dimension in the first protrusion is larger than that of the solid rib in the conventional example, the wider the first protrusion, the more It becomes possible to reduce the area of each of a large number of partitioned areas partitioned by the ridges, and increase the rigidity of the surrounding wall.

  By the way, the higher the rigidity of the surrounding wall, the higher the natural frequency of the surrounding wall, so the surrounding wall vibrates with periodic or non-periodic motion (vibration force) of the motion mechanism. Is suppressed. In short, in the configuration of the present invention, the vibration sensitivity of the surrounding wall with respect to the vibration force can be lowered.

  By the way, in the case where solid ribs are installed in a lattice shape as in the conventional example, in order to reduce the area of each partition region, it is necessary to increase the number of ribs installed so as to reduce the separation size of each of the ribs. Therefore, there is concern that it will lead to an increase in weight.

  In short, in the configuration of the present invention, in order to reduce the area of each partition region partitioned by both the ridges, it is only necessary to make the first ridges wide, so the number of installations is the same as the conventional example. There is no need to increase it. Therefore, even if the mass of the curved first protrusion is larger than that of the conventional solid square rib, the number of first protrusions can be reduced as described above. It can be said that the weight of the surrounding wall of the invention can be set to a level comparable to that of the conventional example. Therefore, even if the surrounding wall of the present invention has substantially the same weight as the surrounding wall of the conventional example, the present invention can be adjusted in the direction of increasing the natural frequency of the surrounding wall as much as possible.

  Preferably, the first ridge and the second ridge are provided so as to be orthogonal to each other, and each partition region partitioned vertically and horizontally by the first ridge and the second ridge, It is square in plan view.

  According to this configuration, a large number of partitioned regions are regularly arranged in, for example, a lattice shape. For example, by appropriately adjusting the area of each partitioned region, a desired vibration suppression effect can be obtained. Design can be performed. This design itself is also simpler than the case where the concave surface portions and the convex surface portions are randomly arranged as in the conventional example.

  Preferably, at least one of the protrusions is arranged so that the respective separation widths are not uniform.

  According to this configuration, the length of one side of many partitioned areas is different, the area of each partitioned area becomes non-uniform, and the rigidity and vibration suppression effect of the surrounding wall can be adjusted arbitrarily. It becomes.

  Preferably, the second protrusion is a solid rib provided to protrude outward on the outer surface.

  In this way, if the second ridge portion is made like a solid rib, the weight increase can be reduced by the amount of the smaller mass when the number of installations is the same as the curved shape. This is advantageous.

  However, the 2nd protrusion part can also be made into a curved shape similarly to the said 1st protrusion part, The form is also contained in this invention.

  Preferably, the surrounding wall has a cylindrical shape or a truncated conical cylinder shape, and the longitudinal direction of the first protrusion is arranged substantially parallel to the central axis.

  The truncated conical cylinder shape refers to a shape obtained by cutting a sharp portion in the conical cylinder shape, and is a trapezoid when viewed from the side.

  In this configuration, the shape of the surrounding wall is specified. In the surrounding wall having such a shape, the first protrusion is curved and the second protrusion is a solid rib, and the longitudinal direction of the first protrusion is cylindrical or truncated cone. When the shape is parallel to the central axis of the surrounding wall, on the inner surface side of the surrounding wall, a belt-like concave surface serving as the inner surface of each first protrusion and a belt-like convex surface between the first protrusions are formed. Will be.

  For this reason, when an enclosure wall having a cylindrical shape or a truncated conical cylinder shape is produced by, for example, a casting method, when the core is removed as a molding die for securing the inner space of the enclosure wall, The child can be pulled out in the direction of the central axis.

  ADVANTAGE OF THE INVENTION According to this invention, the effect which suppresses generation | occurrence | production of the vibration and noise resulting from the exercise | movement of an exercise | movement mechanism can be heightened, although it is the shape which can be designed easily and can suppress a weight increase.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 6 show an embodiment of the present invention.

  In this embodiment, the case where the surrounding wall is a case in a rear wheel drive type (FR type) transmission mounted on an automobile is taken as an example.

  As shown in FIGS. 1 and 2, a transmission 2 is attached to the side of the engine 1. The case 3 of the transmission 2 has a four-part structure including a front end portion 3a, a body portion 3b, a rear end portion 3c, and an oil pan 3d. The front end portion 3a, the body portion 3b, and the rear end portion 3c all have a truncated cone shape, and are inclined at different angles.

  The front end portion 3a covers a clutch mechanism in the case of a manual transmission, and covers a torque converter and the like in the case of an automatic transmission. Various types of gears are provided on the body portion 3b and the rear end portion 3c. Is to be stored.

  Generally, in the transmission 2, due to periodic or non-periodic movement (vibration force) of a gear train (not shown) and other movement mechanisms (not shown) in the transmission 2, Case 3 may vibrate.

  In the transmission 2, the wall portions of the elements 3 a to 3 d constituting the case 3 are devised to reduce the weight, increase the rigidity, and suppress vibrations.

  Specifically, the wall portion of the case 3 is provided substantially in parallel with each other and a large number of first protrusions 5 projecting outward and substantially parallel to each other so as to cross the first protrusions 5. And a large number of second protrusions 6 that protrude outwardly.

  As shown in FIG. 5, the first protrusion 5 has a shape in which a cross section in a direction orthogonal to the longitudinal direction is curved in a partial arc shape.

  As shown in FIG. 6, the second protrusion 6 is a solid rib provided so as to protrude outward on the outer surface of the wall of the case 3, and a cross section in a direction perpendicular to the longitudinal direction thereof. Is substantially trapezoidal. The cross-sectional shape is not particularly limited, for example, a square, a rectangle, a triangle, a semicircle, or the like.

  The first protrusion 5 is provided such that the longitudinal direction thereof is substantially parallel to the central axis P of the case 3, and the second protrusion 6 is substantially orthogonal to the first protrusion 5. That is, it is provided along the circumferential direction of the case 3.

  Further, the separation width of each of the large number of first protrusions 5 and the separation width of the large numbers of second protrusions 6 are all set to be uniform. Furthermore, the curvature of the curved shape part of many 1st protrusion part 5 is mutually set the same.

  However, the width of each of the first protrusions 5 and the width of each of the second protrusions 6, the separation width of each of the first protrusions 5 and the separation width of each of the second protrusions 6, and the first protrusions The crossing angle of the second ridge 6 with respect to 5 is arbitrary, and by adjusting them appropriately, it is possible to perform tuning to ensure the target case 3 rigidity and vibration suppression effect. is there.

  In particular, regarding the movement status of the movement mechanism inside the transmission 2, the phenomenon of the transmission case 3 oscillating due to the movement of the movement mechanism is grasped by experiments and the like in consideration of the generally considered use situation of the vehicle. It is preferable to reduce or prevent the occurrence of the vibration by performing the tuning described above based on the grasped experimental result.

  Thus, while making the 1st protrusion part 5 into a curved shape, the 2nd protrusion part 6 is made into a solid rib, the separation width of each 1st protrusion part 5 and each 2nd protrusion part 6 individual separation. When the width is uniform, the outer surface of the wall portion of the case 3 has a large number of concave surfaces that are substantially rectangular in plan view with the two ridges 5 and 6 provided in a grid shape vertically and horizontally as shown in FIG. As shown in FIG. 3, a band-shaped concave surface 5a serving as an inner surface of each first protrusion 5 and an adjacent first protrusion are formed on the inner surface of the wall portion of the case 3, as shown in FIG. A large number of partitioned regions 8 each having a belt-like convex surface in plan view are formed between the strips 5.

  Among these, since the first protrusion 5 is wide, it is possible to make the length dimension of one side in the partition region 7 formed of the concave surface of the outer surface of the case 3 as small as possible. The area of the partition region 7 can be reduced, and the rigidity of the case 3 can be increased.

  If the number of solid ribs installed in the conventional example is the same as the number of installed first ridges 5 in this embodiment, the wider the first ridges 5 are, It becomes possible to reduce the area of each of the multiple partition regions 7 on the outer surface side partitioned by the first and second protrusions 5 and 6, and the rigidity of the case 3 can be increased.

  Incidentally, as the rigidity of the case 3 increases, it becomes possible to adjust the natural frequency of the case 3 in a direction to increase the natural frequency. The vibration of the case 3 with the force) is suppressed. This means that the vibration sensitivity of case 3 with respect to the vibration force can be lowered.

  For reference, in the case where solid ribs are installed in a grid pattern as in the conventional example, in order to reduce the area of each of the partition areas 7 on the outer surface side, the ribs are set so as to reduce the distance between the ribs. It is necessary to increase the number of installations, leading to an increase in weight.

  However, in this embodiment, in order to reduce the area of each of the partition regions 7 on the outer surface side partitioned by the first and second protrusions 5 and 6, it is only necessary to make the first protrusions 5 wide. It is not necessary to increase the number of installations as in the conventional example. Even if the mass of the curved first protrusion 5 is larger than that of the conventional solid square rib, the number of the first protrusions 5 can be reduced as described above. The weight of 3 can be made substantially equal to that of the conventional example. That is, even when the case 3 has substantially the same weight as the case where solid ribs are installed in a lattice shape as in the conventional example, the natural frequency of the case 3 can be adjusted to be high.

  In addition, the inner surface of the case 3 is specified so that the longitudinal directions of the band-shaped concave surface 5a of the first protrusion 5 and the partition region 8 formed of the band-shaped convex surface are parallel to the central axis P of the case 3, respectively. When the case 3 is manufactured by, for example, a casting method, the core can be pulled out in the direction of the central axis P when the core as a molding die for securing the inner space of the case 3 is pulled out. Become.

  As described above, in the embodiment to which the present invention is applied, the inner surface of the wall portion of the case 3 is provided by providing the first and second protrusions 5 and 6 so as to intersect the wall portion of the case 3 of the transmission 2. Are made uneven, and the area of the partition region 7 provided on the outer surface side of the intersecting portion can be made as small as possible.

  As a result, the rigidity of the case 3 can be increased as compared with the conventional example in which the inner surface of the wall portion is a flat surface extending in a wide range, and a solid rib is latticed on the outer surface of the wall portion as in the conventional example. Compared with the case where it is provided in a shape, the vibration suppressing effect can be enhanced without increasing the weight more than necessary.

  Hereinafter, other embodiments of the present invention will be described.

  (1) FIGS. 7 to 12 show other embodiments of the present invention. In this embodiment, the case where the surrounding wall is the timing cover 10 of the engine 1 as shown in FIG. 7 is taken as an example.

  As shown in FIGS. 7 and 8, the timing cover 10 conceals and protects the motion mechanism of the power transmission system for transmitting the power of the crankshaft 11 to the intake and exhaust camshafts 12 and 13. The engine 1 is detachably attached to the front end surface (corresponding to the front end surfaces of a cylinder block, a cylinder head, and a crankcase, although not shown in detail).

  As shown in FIG. 8, the movement mechanism of the power transmission system includes a timing gear 21 attached to the front end side of the crankshaft 11, a timing gear 22 attached to the front end side of the intake side camshaft 12, and an exhaust side. A timing gear 23 attached to the front end side of the camshaft 13, an endless timing chain (or timing belt) 24 wound around these timing gears 21 to 23, and a tensioner that automatically adjusts the tension of the timing chain 24 25. Generally, the power transmission ratio is such that when the crankshaft 11 rotates twice, the intake and exhaust camshafts 12 and 13 rotate once.

  Since such a timing cover 10 may also generate vibrations due to the movement by the movement mechanism of the power transmission system therein, in order to suppress this vibration, the first cover as described in the above embodiment is used. A ridge 5 and a second ridge 6 are provided.

  In this embodiment, the first protrusion 5 is provided on the front wall of the timing cover 10 so as to be substantially parallel to the longitudinal direction (longitudinal direction) of the engine 1, and the second protrusion 6 is provided. The front wall portion of the timing cover 10 is provided so as to be substantially parallel to the lateral direction (width direction) of the engine 1, and the first protrusion 5 and the second protrusion 6 intersect each other substantially orthogonally. Yes.

  Further, on the outer surface of the front wall portion of the timing cover 10, as shown in FIGS. 7 and 10, a substantially rectangular partition region 7 is provided at the intersection of the first protrusion 5 and the second protrusion 6. It is like that. On the other hand, on the inner surface of the front wall portion of the timing cover 10, as shown in FIG. 9, a plan view is formed between the strip-shaped concave surface 5 a serving as the inner surface of each first protrusion 5 and each adjacent first protrusion 5. Thus, a large number of partitioned regions 8 each having a belt-like convex surface are formed.

  Also in this embodiment, the target vibration suppressing effect can be obtained by adjusting the area of the partition region 7 and the like as appropriate, similarly to the above embodiment.

  With such a configuration, the rigidity of the timing cover 10 is improved and vibration of the timing cover 10 is improved while the design is easy and the weight increase more than necessary is suppressed as much as possible, basically as in the above embodiment. It becomes possible to suppress.

  (2) In each of the above embodiments, an example is given in which all the first ridges 5 have the same curvature. For example, as shown in FIG. You may make it let. About the combination pattern of the 1st protrusion part 5 from which this curvature differs, it is arbitrary.

  (3) In each of the above embodiments, an example is given in which the cross-sectional shapes of the second ridge portions 6 are all the same, but for example, as shown in FIG. It may be included. About the combination pattern of the 2nd protrusion part 6 from which this cross-sectional shape differs, it is arbitrary.

  In FIG. 14, most of the second ridges 6 have a substantially trapezoidal cross section, and a predetermined number of the second ridges 6 have a substantially semicircular cross section, and the width in the direction perpendicular to the longitudinal direction is set larger than the others. is doing.

  (4) In each of the above embodiments, the first protrusion 5 is curved and the second protrusion 6 is a solid rib similar to the conventional example. Both 5 and the 2nd protrusion part 6 can be made into a curved shape.

  Here, as an example, FIG. 15 shows an example in which the first and second protrusions 5 and 6 provided in the transmission case 3 of the embodiment shown in FIGS. 1 to 6 are both curved. In this figure, the second ridge portion 6 has the same curved shape as the first ridge portion 5.

  In this case, since both the first protrusion 5 and the second protrusion 6 are wide, the area of the partition region 7 on the outer surface side provided at the intersection thereof is the same as the number of installations in each of the above embodiments. Then, it becomes possible to make smaller than said each embodiment.

  As a result, the natural frequency in the transmission case 3 as the surrounding wall can be adjusted in a higher direction than in the above embodiments, and the adjustment range when adjusting the vibration suppression effect can be further expanded. become.

  Of course, the configuration in which the first and second protrusions 5 and 6 are both curved as described above is applied to the timing cover 10 and other appropriate surrounding walls of the embodiment shown in (1) above. Is possible. Moreover, you may set the curvature of the 1st protrusion part 5 and the curvature of the 2nd protrusion part 6 so that it may differ.

It is a perspective view which shows the transmission case as one Embodiment of the surrounding wall which concerns on this invention. It is a perspective view which decomposes | disassembles and shows the transmission case of FIG. It is the perspective view which looked at the area | region currently expanded and extracted in FIG. 1 from the inner surface side. It is the figure which planarly viewed the area | region currently expanded and extracted in FIG. 1 from the outer surface side. FIG. 4 is a cross-sectional view taken along line (5)-(5) in FIG. 3. It is an arrow view of the (6)-(6) line cross section of FIG. It is a perspective view which shows the timing cover as other embodiment of the surrounding wall which concerns on this invention. It is a front view which shows the moving mechanism of the power transmission system arrange | positioned at the front-end side of the engine of FIG. It is the perspective view which looked at the area | region currently expanded and extracted in FIG. 7 from the inner surface side. It is the figure which planarly viewed the area | region currently expanded and extracted in FIG. 7 from the outer surface side. It is an arrow view of the (10)-(10) line cross section of FIG. It is an arrow view of the (11)-(11) line cross section of FIG. FIG. 6 is a view corresponding to FIG. 5 in another embodiment of the surrounding wall according to the present invention. FIG. 7 is a view corresponding to FIG. 6 in another embodiment of the surrounding wall according to the present invention. It is other embodiment of the surrounding wall which concerns on this invention, and is a perspective view corresponding to the expansion extraction area | region of FIG.

Explanation of symbols

1 engine
2 Transmission
3 Transmission case (enclosure wall)
3a Front end of the case
3b Case body
3c Rear end of the case
5 First ridge
6 Second ridge
7 Partition area on the outer surface
8 Partition area on the inner surface side

Claims (5)

A surrounding wall that covers the motion mechanism, and is provided with a plurality of first protrusions that are provided substantially parallel to each other and projecting outward, and are provided substantially in parallel with each other so as to cross the first protrusions and outward. A plurality of second protrusions projecting to
The surrounding wall of the motion mechanism characterized in that at least the first protrusion has a shape in which a cross section in a direction perpendicular to the longitudinal direction is curved in a partial arc shape.   The surrounding wall of Claim 1 WHEREIN: The said 1st protrusion part and the 2nd protrusion part are provided so that it may mutually orthogonally cross, and it divides vertically and horizontally by these 1st protrusion part and 2nd protrusion part. An encircling wall of a motion mechanism, wherein each of the divided areas is rectangular in plan view.   The enclosure wall according to claim 1 or 2, wherein at least one of the protrusions is arranged so that the respective separation widths are not uniform.   The surrounding wall according to any one of claims 1 to 3, wherein the second protrusion is a solid rib provided to protrude outward on the outer surface. Siege wall.   The surrounding wall according to any one of claims 1 to 4, wherein the surrounding wall has a cylindrical shape or a truncated cone shape, and a longitudinal direction of the first protrusion is arranged substantially parallel to a central axis thereof. Enclosure wall of the movement mechanism to do.

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