JP6149159B2 - Oil pan - Google Patents

Description

  The present invention relates to an oil pan attached to a lower surface side of a transmission or the like.

  Conventionally, Patent Document 1 discloses a technique in which a rib is provided in the vicinity of a bolt mounting portion of an oil pan to ensure the strength of the oil pan.

  In recent years, for the purpose of improving fuel efficiency, it has been desired to reduce the amount of oil from the viewpoint of reducing friction and cost reduction when oil is lifted by a gear in a transmission. However, if the amount of oil is reduced, the oil level will decrease, and when a large acceleration / deceleration occurs during sudden braking or sudden start, the strainer opening for sucking oil from the oil pan will be exposed and air There was a problem that air sucking phenomenon occurred. Since the air sucking phenomenon affects the hydraulic control of the transmission, it must be suppressed as much as possible.

JP 2011-112126 A

An object of the present invention is to provide an oil pan capable of suppressing an air sucking phenomenon from a strainer.
In order to achieve the above object, according to the present invention, there is provided an oil pan comprising a bottom portion and an outer peripheral wall erected on the outer periphery of the bottom portion, on both sides of an axis in the vehicle front-rear direction passing through an opening of a strainer for sucking oil. In addition, the first and second oil flow suppression portions that form the wall portion by projecting upward from the bottom portion in the vehicle vertical direction are provided.

  Therefore, the flow range of the oil around the opening of the strainer is suppressed, and the oil level in the vicinity of the opening of the strainer can be secured. Further, the amount of oil can be reduced by reducing the volume of the oil pan. Further, by projecting the bottom of the oil pan and providing the oil flow restraining portions on both sides, the rigidity of the oil pan due to the rib effect can be improved, and the impact resistance from the outside can be improved.

3 is a plan view illustrating an oil pan according to Embodiment 1. FIG. 2 is a bottom view illustrating an oil pan according to Embodiment 1. FIG. 2 is a cross-sectional view of the oil pan of Example 1 taken along line AA. FIG. It is a characteristic view showing the relationship between the inclination of a 1st and 2nd control wall part, and a limit deceleration. It is a characteristic view showing the relationship between the clearance β between the opening of the strainer and the rear bottom and the critical deceleration. It is the schematic showing the air pocket phenomenon which arises in an oil level when oil is inhaled at the predetermined low temperature.

  FIG. 1 is a plan view illustrating an oil pan according to the first embodiment, FIG. 2 is a bottom view illustrating the oil pan according to the first embodiment, and FIG. 3 is a cross-sectional view taken along line AA of the oil pan according to the first embodiment. 1-3, the x axis represents the vehicle front-rear direction (the positive direction is the front of the vehicle), the y axis represents the vehicle width direction (the positive direction is the left side of the vehicle), and the z axis is the vehicle vertical direction (the positive direction is the upper side of the vehicle). Represents. The oil pan 1 has a bottom portion 10 and an outer peripheral wall 11 erected on the outer periphery of the bottom portion 10. A flange portion 12 is formed at the opening end of the outer peripheral wall 11. The flange portion 12 has a plurality of bolt holes 12a through which bolts for fixing from the lower surface side of the transmission housing (not shown) are inserted. The oil pan 1 is provided with a strainer 2 for sucking oil by driving an oil pump provided in a transmission (not shown). The strainer 2 has an opening 21 that opens toward the vehicle lower side and sucks oil, and a filter portion 22 that filters the oil sucked from the opening 21.

  As shown in FIG. 1, the oil pan 1 is roughly divided into three regions in the vehicle front-rear direction. The rear region is a region where the opening 21 of the strainer 2 is located, and the depth of the oil level is required. In the oil pan 1 of the first embodiment, the opening 21 of the strainer 2 is disposed on the vehicle rear side from the viewpoint of securing the oil level during sudden braking. The rear bottom 10a, which is the bottom 10 of the rear region, is formed so as to be substantially horizontal when mounted.

  The intermediate bottom portion 10b, which is the bottom portion 10 of the intermediate region, is formed as an inclined surface that gradually rises upward from the rear region to the front region when the vehicle is mounted. The intermediate bottom portion 10b includes a first oil flow suppressing portion 101 and a second oil flow suppressing portion 102 that are formed so as to protrude upward from the intermediate bottom portion 10b. The first oil flow suppression part 101 is formed along the vehicle front-rear direction and the first restriction wall part 101 a formed on the vehicle rear side so as to intersect the vehicle front-rear direction with a predetermined angle. And a first guide wall portion 101b that becomes higher as it goes to. Similarly, the second oil flow suppression portion 102 is formed on the vehicle rear side, and is formed along the vehicle front-rear direction with a second restriction wall portion 102a that intersects the vehicle front-rear direction with a predetermined angle. And a second guide wall portion 102b that becomes higher as it goes to.

  The intermediate bottom portion 10b between the first guide wall portion 101b and the second guide wall portion 102b serves as a flow path for oil to move to the front region in response to braking or the like, and returns the moved oil to the rear region. A flow path bottom 103 serving as a flow path for this purpose. In other words, the first oil flow suppression unit 101 and the second oil flow suppression unit 102 are provided at positions that overlap at least on the vehicle rear side when viewed from the y-axis direction. Thereby, the oil flow is effectively suppressed in the vicinity of the opening 21 of the strainer 2 by the first restriction wall 101a and the second restriction wall 102a. In addition, the first guide wall portion 101b, the second guide wall portion 102b, and the flow path bottom portion 103 form a flow path for effectively flowing oil in the vicinity of the opening 21 of the strainer 2. Further, when the line passing through the end on the most negative side in the y-axis of the first guide wall 101b is Q1, and the line passing through the end on the most positive side in the y-axis of the second guide wall 102b is Q2, Q1 A line Q3 passing through the center of Q2 is provided at a position overlapping the opening 21 of the strainer 2 (see FIG. 2). Therefore, when oil flows, since it circulates in the vicinity of the opening 21, the oil level in the vicinity of the opening 21 can be secured.

  The front bottom portion 10c, which is the bottom portion 10 of the front region, is formed as an inclined surface having an inclination larger than that of the intermediate bottom portion 10b when the vehicle is mounted (which increases greatly toward the front of the vehicle). In the first embodiment, the intermediate bottom portion 10b and the front bottom portion 10c are continuously connected. In other words, the first oil flow suppression unit 101 and the second oil flow suppression unit 102 are configured such that no wall portion is provided on the vehicle front side. Therefore, the oil that has flowed toward the front bottom portion 10c can be smoothly returned to the rear bottom portion 10a. In addition, when providing a wall part in the vehicle forward side of the 1st oil flow suppression part 101 or the 2nd oil flow suppression part 102, a wall part lower than the height of the 1st control wall part 101a or the 2nd control wall part 102a Is desirable. Thus, by suppressing the protrusion amount of the 1st oil flow suppression part 101 and the 2nd oil flow suppression part 102 in an intermediate area, interference with the strainer 2 and the structure on the transmission side can be suppressed.

  Further, in the vehicle mounted state, the height position in the z-axis direction of the front end portion 10c1 of the front bottom portion 10c where the outer peripheral wall 11 rises is higher than the height position in the z-axis direction of the vehicle rear end portion 121 of the flange portion 12. Installed. Thus, the front bottom portion 10c is largely raised, thereby avoiding contact of an obstacle or the like with the wall surface of the outer peripheral wall 11 on the vehicle front side standing from the front bottom portion 10c. That is, since the wall surface of the outer peripheral wall 11 is easy to input force from an obstacle or the like, the impact on the oil pan 1 is likely to increase. On the other hand, if it is an inclined surface like the front bottom part 10c, since the force from an obstruction etc. will be disperse | distributed and input, the improvement of the durability of the oil pan 1 will be aimed at. Further, the front end portion 10c1 is higher than the height position of the vehicle rear end portion 121 in the z-axis direction. As a result, the oil that has moved to the front region of the oil pan 1 is easily collected in the rear region where the opening 21 of the strainer 2 is located, and the oil level in the rear region is ensured.

(About 1st and 2nd regulation wall part)
FIG. 4 is a characteristic diagram showing the relationship between the inclination of the first and second restriction walls and the limit deceleration. Here, the wall surface direction in which the wall surfaces of the first and second regulating wall portions 101a and 102a extend in the vehicle width direction is defined as P1 (see FIG. 2), and the y-axis direction that is the vehicle width direction. The angle formed is defined as α. The limit deceleration represents a deceleration at which an air sucking phenomenon from the strainer 2 occurs when a predetermined deceleration is generated in the vehicle. As shown in FIG. 4, when α is gradually increased from 0 degrees (in the y-axis direction), it has been found that the limit deceleration gradually increases and descends with about 50 degrees as a vertex. . If α is too large, the oil in the rear region easily moves to the front region when deceleration occurs, and it becomes difficult to retain the oil in the rear region, that is, to ensure the oil level. On the other hand, if α is too small, the oil cannot be efficiently guided to the opening 21 of the strainer 2, and it is difficult to ensure the oil level.

  In actual vehicle application, the occurrence of the air sucking phenomenon can be suppressed even when the maximum deceleration that can occur in the vehicle is in the range of approximately 30 degrees to approximately 70 degrees. Therefore, in the first embodiment, α is set to approximately 50 degrees, and oil movement during deceleration is appropriately suppressed. In addition, what is necessary is just to set suitably in the range of about 30 degree | times to about 70 degree | times not only about 50 degree | times. In the first embodiment, the angle formed between the first restriction wall portion 101a and the y-axis direction and the angle formed between the second restriction wall portion 102a and the y-axis direction are substantially coincident with each other, but approximately 30 degrees. May be set to a different angle within a range of approximately 70 degrees.

(Relationship between gap β between strainer opening and rear bottom and limit deceleration)
FIG. 5 is a characteristic diagram showing the relationship between the clearance β between the opening 21 of the strainer 2 and the rear bottom 10a and the limit deceleration. Let β be the gap between the opening 21 of the strainer 2 and the rear bottom 10a (see FIG. 2). The solid line in FIG. 5 represents the relationship between the gap β and the critical deceleration at room temperature. When the gap β is gradually changed at room temperature, the critical deceleration can be secured larger as the gap β is smaller. When the gap β is increased, the oil viscosity is low and the flow performance is secured. The speed starts to decrease greatly. Therefore, the condition for satisfying the maximum deceleration requires that the gap β is equal to or less than β1.

Next, it is assumed that the gap β is gradually changed at a predetermined low temperature (for example, −30 ° C.). The dotted line in FIG. 5 represents the relationship between the gap β and the limit deceleration at a predetermined low temperature. At a predetermined low temperature, the viscosity of the oil increases like a starch candy. Therefore, since the flow of oil is suppressed, even if the gap β is increased, the oil level is hardly lowered due to the occurrence of deceleration. However, if the gap β is reduced and oil is sucked locally, the limit deceleration tends to decrease.
FIG. 6 is a schematic diagram showing an air pocket phenomenon that occurs in the oil level when oil is sucked in at a predetermined low temperature. Since the viscosity of the oil is high and the flow is suppressed, other oils are less likely to flow into the portion of the oil level that has been lowered by suction, and a phenomenon in which the oil level partially decreases occurs. This is called the air pocket phenomenon.
Therefore, as shown in the characteristic diagram shown by the dotted line in FIG. 5, when the gap β is reduced, the local oil level is lowered due to the air pocket phenomenon, and the air sucking phenomenon is likely to occur. Therefore, the condition for satisfying the maximum deceleration requires that the gap β is equal to or greater than β0. Therefore, β satisfying both the temperature conditions is a region of β0 <β <β1. By setting the gap β so as to be in this range, the air sucking phenomenon can be stably suppressed regardless of the temperature condition.

As described above, the effects listed below are obtained in the first embodiment.
(1) An oil pan 1 comprising a bottom portion 10 and an outer peripheral wall 11 erected on the outer periphery of the bottom portion 10, and a line Q3 (axis in the vehicle front-rear direction) passing through an opening of a strainer 2 for sucking oil On both sides, first and second oil flow suppression portions 101 and 102 that form walls by protruding upward from the bottom 10 in the vehicle vertical direction are provided.
Therefore, the oil flow range around the opening 21 of the strainer 2 is suppressed, and the oil level in the vicinity of the opening 21 of the strainer 2 can be secured. Further, the amount of oil can be reduced by reducing the volume of the oil pan 1. Moreover, since the bottom part 10 of the oil pan 1 protrudes, the rigidity of the oil pan 1 can be improved by the rib effect between the first and second oil flow suppression parts, and the impact resistance from the outside can be improved.

(2) The line Q3 (vehicle longitudinal axis) passing through the opening 21 of the strainer 2 passes through the center of the closest part between the first oil flow suppression unit 101 and the second oil flow suppression unit 102.
Therefore, when the oil flows due to sudden acceleration / deceleration caused by the vehicle, the oil level in the vicinity of the opening 21 can be reliably ensured because the flow path includes the opening 21 in the front-rear direction.

  (3) The strainer 2 opens in a rear region of the bottom portion 10 (a position on one side of the center in the vehicle front-rear direction), and the first restriction wall portion 101a and the second restriction wall portion 101a of the first and second oil flow suppression portions 101, 102. The height in the vehicle vertical direction of the restriction wall portion 102a (the wall portion on the one side in the vehicle longitudinal direction) is higher than the wall portion in the front region (the other side). In the case of Example 1, it is set as the structure which does not provide a wall part in the vehicle forward side of the 1st oil flow suppression part 101 or the 2nd oil flow suppression part 102. FIG. Therefore, the oil that has flowed toward the front bottom portion 10c can be smoothly returned to the rear bottom portion 10a. In addition, when providing a wall part in the vehicle forward side of the 1st oil flow suppression part 101 or the 2nd oil flow suppression part 102, a wall part lower than the height of the 1st control wall part 101a or the 2nd control wall part 102a Is desirable. Thus, by suppressing the protrusion amount of the 1st oil flow suppression part 101 and the 2nd oil flow suppression part 102 in an intermediate area, interference with the strainer 2 and the structure on the transmission side can be suppressed.

(4) The strainer 2 opens in a rear region of the bottom portion 10 (a position on one side of the center in the vehicle front-rear direction), and the first restriction wall portions 101a and second of the first and second oil flow suppression portions 101 and 102. The extending direction in which the restriction wall portion 102a (the wall portion on the one side in the vehicle front-rear direction) extends intersects with the y-axis direction (vehicle width direction) at an angle of 30 degrees to 70 degrees.
Therefore, the movement of the oil in the front-rear direction by the vehicle restricts the flow direction of the oil by both restriction walls, moderately suppresses the movement due to the flow of the oil, and the oil effectively flows into the opening 21 of the strainer 2. And the occurrence of the air sucking phenomenon can be suppressed.

(5) The upper end position in the z-axis direction (vehicle vertical direction) of the front end portion 10c1 (vehicle front-rear direction front end portion) of the bottom portion 10 is the vehicle rear end portion 121 (the vehicle front-rear direction rear end portion of the outer peripheral wall). ) Is mounted on the vehicle so as to be higher than the upper end position in the vehicle vertical direction.
Thereby, the oil moved to the front area of the oil pan 1 can be easily collected in the rear area where the opening 21 of the strainer 2 is located, and the oil level in the rear area can be secured.

  (6) The strainer 2 opens toward the vehicle rear side from the vehicle longitudinal direction center of the bottom portion 10. Therefore, the oil level can be effectively ensured at the time of deceleration at which a large speed change occurs as compared with the time of acceleration.

(7) The first and second oil flow suppression portions 101 and 102 are formed at the same position in the vehicle front-rear direction.
Therefore, the oil flow range is effectively suppressed in the vicinity of the opening 21 of the strainer 2 by the first restriction wall 101a and the second restriction wall 102a. In addition, the first guide wall part 101b, the second guide wall part 102b, and the flow path bottom part 103 can form a flow path for allowing oil to flow effectively in the vicinity of the opening 21 of the strainer 2.

(8) The maximum value of the gap β between the opening 21 and the bottom part 10 of the strainer 2 is set to be equal to or less than β1 (first predetermined value) that can avoid the air sucking phenomenon at room temperature, and the minimum value of the gap β is set at a predetermined low temperature. It was set to β0 (second predetermined value) or more that can avoid the air sucking phenomenon.
The oil has good fluidity at room temperature due to its low viscosity. Therefore, the gap β1 or less that can avoid the air sucking phenomenon even at the maximum deceleration at normal temperature is set. On the other hand, since the viscosity of oil is high at a predetermined low temperature, the fluidity of the oil is poor, and an air sucking phenomenon occurs due to the air pocket phenomenon. Therefore, even if the air pocket phenomenon occurs, the gap β0 or more that can avoid the air sucking phenomenon is set. Thereby, the air sucking phenomenon can be stably suppressed regardless of the temperature condition.

  Although the present invention has been described above based on the first embodiment, the present invention is not limited to the above configuration, and other configurations may be used as long as they are within the scope of the invention. In the first embodiment, when the first guide wall portion 101b and the second guide wall portion 102b are formed, the position of the end portion in the y-axis direction of the opening 21 of the strainer 2 and the lines Q1 and Q2 are set to substantially coincide with each other. However, it does not necessarily have to match. The line Q3 only needs to pass through the opening 21 of the strainer 2, and the line Q3 may pass through a position shifted from the center of the opening 21 of the strainer 2.

Claims (7)

An oil pan comprising a bottom and an outer peripheral wall standing on the outer periphery of the bottom,
A first oil flow suppression portion and a second oil flow suppression portion projecting upward from the bottom portion in the vehicle vertical direction are provided on both sides of the vehicle longitudinal axis passing through the opening of the strainer for sucking oil;
The first oil flow suppression unit and the second oil flow suppression unit are
A restriction wall extending in the vehicle width direction;
A guide wall extending in the longitudinal direction of the vehicle;
Each with
An oil flow path toward the opening is formed between the guide wall portion of the first oil flow suppression portion and the guide wall portion of the second oil flow suppression portion ,
The strainer opens at a position on one side of the vehicle front-rear direction center of the bottom,
An oil pan in which a vehicle vertical direction height of a wall portion on one side in the vehicle front-rear direction of the first and second oil flow suppression portions is higher than a wall portion on the other side . The oil pan according to claim 1,
An oil pan in which a vehicle longitudinal axis passing through the opening of the strainer passes through a substantially center between a guide wall portion of the first oil flow suppression portion and a guide wall portion of the second oil flow suppression portion. The oil pan according to claim 1 or 2 ,
The wall surface of the first and second oil flow suppression portions on one side in the vehicle front-rear direction extending in the vehicle width direction has an angle of approximately 30 degrees or more and approximately 70 degrees or less with respect to the vehicle width direction. Oil pans that intersect. The oil pan according to any one of claims 1 to 3 ,
An oil pan mounted on a vehicle such that a vehicle vertical direction upper end position of a vehicle front-rear direction front end portion of the bottom portion is higher than a vehicle vertical direction upper end position of a vehicle front-rear direction rear end portion of the outer peripheral wall. The oil pan according to any one of claims 1 to 4 ,
The opening of the strainer is an oil pan provided on the rear side of a vehicle front-rear direction center of the bottom. The oil pan according to any one of claims 1 to 5 ,
The said 1st and 2nd oil flow suppression part is an oil pan currently formed in the same position in the vehicle front-back direction. The oil pan according to any one of claims 1 to 6 ,
The maximum value of the gap between the opening and the bottom of the strainer is not more than a first predetermined value that can avoid the air sucking phenomenon at room temperature, and the minimum value of the gap is the second predetermined value that can avoid the air sucking phenomenon at a predetermined low temperature. Oil pan that was above the value.

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