JP7451035B2 - oil strainer - Google Patents

Description

The present invention relates to an oil strainer.

2. Description of the Related Art In automatic transmissions such as CVTs (Continuously Variable Transmissions) installed in vehicles, an oil pan for storing oil is attached to the bottom of a case that forms the outer shell of the automatic transmission. The oil stored in the oil pan is sucked up by the oil pump through the oil strainer, and then passed through the valve body, which is equipped with various valves for controlling oil supply, to each part that requires oil supply. Supplied as a lubricant.

While the vehicle is running, oil is stirred within the case and sprayed onto various parts for lubrication. Therefore, while the vehicle is running, the oil contains minute bubbles. After the vehicle stops running, the flow of oil in the case stops, and air bubbles in the oil gradually collect in the oil strainer to form air pockets. If there is air trapped inside the oil strainer, when the oil pump starts, the air trapped becomes large bubbles that flow into the oil pump, causing air trapping that can cause abnormal noise and malfunction in the oil pump. Occur.

JP 2017-160955 Publication

Therefore, in the conventional oil strainer, the top surface portion where the outlet for draining the oil from inside the oil strainer is formed is sloped monotonically upward toward the outlet. Thereby, after the oil pump is stopped, the air bubbles contained in the oil move toward the outlet due to buoyancy along the slope, and it is possible to suppress the formation of air pockets due to air bubbles gathering in the oil strainer.

In order to avoid interference with members disposed above the oil strainer, a convex shape that is convex inward may be formed on the top surface. If the top surface has a convex shape, the top surface cannot be sloped monotonically upward toward the outlet, and the convex portion of the top surface has undulations. Air may accumulate in some areas.

Additionally, if the top surface is tilted to avoid the parts placed above the oil strainer instead of forming a convex shape on the top surface, it is possible to avoid the occurrence of undulations on the top surface, which can lead to air accumulation. can be suppressed. However, the top surface must have a large slope, which increases the thickness (vertical size) of the oil strainer, and accordingly increases the volume of the oil strainer. Therefore, especially in small vehicles, such a configuration cannot be adopted.

SUMMARY OF THE INVENTION An object of the present invention is to provide an oil strainer that can suppress air accumulation even if a convex portion that protrudes toward the filtration chamber is formed on the top surface.

In order to achieve the above object, an oil strainer according to the present invention includes a bottom member and an upper member that is butted against the bottom member from above to form a filtration chamber between the bottom member, and the upper member includes: It has a top part that covers the filtration chamber from above, and an outlet that allows oil to flow out from the filtration chamber is formed at the top of the top part, and the top part has a convex part that is convex toward the filtration chamber. On the outside of the convex part, it is inclined to be located upward as it approaches the outlet, and in the convex part, in the non-exit direction that intersects a straight line passing through the outlet and any point within the convex part in plan view. , is inclined so that one side in the non-exit direction is located upward.

According to this configuration, the top surface of the upper member is formed with an outlet through which oil flows out from the filtration chamber between the bottom member and the upper member, and the outlet is positioned upward as it approaches the outlet. It is sloped. In addition, a convex part that is convex toward the filtration chamber side is formed on the top surface, and in this convex part, there is a non-exit that intersects with a straight line passing through an arbitrary point in the convex part and the outlet in plan view. In this direction, the slope is inclined so that one side in the non-exit direction is located higher.

As a result, after the oil pump that sucks oil from the oil pan via the oil strainer stops, air bubbles contained in the oil float up inside the oil to the inner surface of the top panel outside the convex portion. along the slope toward the outlet. On the other hand, in the convex part, the bubbles that have floated up to the inner surface of the top part move toward one side in the non-exit direction along the slope of the top part, and when they reach the outside of the convex part, they move to the outside of the convex part. Move towards the outlet.

Therefore, even if a convex portion that protrudes toward the filtration chamber is formed on the top surface, it is possible to suppress the generation of air pockets. Furthermore, since it is sufficient to eliminate air bubbles from the convex portion, the slope of the top surface portion at the convex portion can be set to a minimum, and an increase in the thickness and volume of the oil strainer can be suppressed.

A rib is formed on the inner surface of the top surface part, which protrudes downward and extends along a straight line passing through the outlet in plan view. It is preferable that the rib angle is set so that it does not become smaller as the rib angle becomes larger.

In this case, for example, the upward slope in the convex portion is set for each of multiple angular ranges of the rib angle, and is larger in the angular range of relatively large rib angles than in the angular range of relatively small rib angles. It may be set as follows.

In a convex part where the top surface is sloped upward to one side in the non-exit direction, if the angle of the rib with respect to the non-exit direction (rib angle) is large, the ribs will prevent the movement of bubbles toward one side in the non-exit direction. There is a risk of being hindered. Therefore, in the portion where the rib angle formed by the rib with respect to the non-exit direction is large, the upward inclination of the top surface portion is set to be large, so that the rib can be moved favorably in the non-exit direction. As a result, the occurrence of air pockets can be further suppressed.

According to the present invention, even if a convex portion that protrudes toward the filtration chamber is formed on the top surface, it is possible to suppress the occurrence of air accumulation. Furthermore, increases in the thickness and volume of the oil strainer can be suppressed.

FIG. 1 is a plan view of an oil strainer according to an embodiment of the present invention. FIG. 3 is a plan view showing the inner surface of the upper case. 2 is a cross-sectional view of the oil strainer taken along the cross-sectional line AA shown in FIG. 1. FIG. 2 is a cross-sectional view of the oil strainer taken along the cross-sectional line BB shown in FIG. 1. FIG. 2 is a cross-sectional view of the oil strainer taken along the cross-sectional line CC shown in FIG. 1. FIG. It is a figure which shows the relationship between a rib angle and the inclination gradient of the top surface part in a convex part.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

<Structure of oil strainer>
FIG. 1 is a plan view of an oil strainer 1 according to an embodiment of the present invention.

The oil strainer 1 is included in an automatic transmission mounted on a vehicle. In an automatic transmission, an oil pan is attached to the bottom of a unit case that forms the outer shell of the automatic transmission, and the oil strainer 1 is disposed within the oil pan. The oil stored in the oil pan is sucked up by an oil pump through an oil strainer 1, and is passed through a valve body equipped with various valves for controlling oil supply to each part that requires oil supply. Or supplied as a lubricant.

The automatic transmission may be a stepped automatic transmission (AT) or a continuously variable transmission (CVT). Further, the automatic transmission may be a power split type continuously variable transmission. A power split type continuously variable transmission, for example, is equipped with a belt-type continuously variable transmission mechanism that changes the power steplessly by changing the gear ratio, and splits the power into two paths between the input shaft and the output shaft. It is a transmission that can be transmitted by

The oil strainer 1 includes a case 11 made of synthetic resin. The case 11 is configured by dividing an upper case 12 and a lower case 13 into upper and lower parts, and has an internal space surrounded by the upper case 12 and lower case 13 as a filtration chamber 14.

FIG. 2 is a plan view showing the inner surface of the upper case 12. FIG. 3 is a cross-sectional view of the oil strainer 1 taken along the cross-sectional line AA shown in FIG. FIG. 4 is a cross-sectional view of the oil strainer 1 taken along the cross-sectional line BB shown in FIG. FIG. 5 is a cross-sectional view of the oil strainer 1 taken along the cross-sectional line CC shown in FIG.

The upper case 12 integrally includes a top surface portion 21 and a side surface portion 22 extending downward from the periphery of the top surface portion 21 . An outflow port 23 is formed in the top surface portion 21 to allow oil to flow out from the filtration chamber 14. An oil pump (not shown) is connected to the outlet 23.

As shown in FIGS. 4 and 5, the lower case 13 integrally includes a bottom plate portion 24 extending in a flat plate shape and a side portion 25 extending upward from the periphery of the bottom plate portion 24. The lower case 13 overlaps the upper case 12 from below, and is fixed to the upper case 12 with the side surface 25 butted against the side surface 22 of the upper case 12. In this state, the bottom plate portion 24 extends substantially parallel to the top surface portion 21 of the upper case 12. An intake port 26 for taking oil stored in the oil pan into the filtration chamber 14 is formed in the bottom plate portion 24 at a position offset to the other side opposite to the one side where the outflow port 23 is formed. has been done.

A filtering material 27 is provided between the upper case 12 and the lower case 13. The filter material 27 is, for example, a nonwoven fabric. The peripheral edge of the filtering material 27 is held between the side surface 22 of the upper case 12 and the side surface 25 of the lower case 13, and the filtering material 27 divides the filtering chamber 14 into upper and lower parts.

<Bubble discharge structure>
For example, in order to avoid interference with members disposed above the oil strainer 1, the top surface 21 of the upper case 12 has a convex surface on the filtration chamber 14 side (inside the case 11), as shown in FIG. A convex portion 31 is formed.

As shown in FIG. 4, outside the convex portion 31, the top surface portion 21 is sloped upward toward the outflow port 23 so as to be located upward as it approaches the outflow port 23. ing.

In the convex portion 31, in the non-exit direction along the straight line L that intersects a straight line passing through an arbitrary point in the convex portion 31 and the outlet 23 in plan view, one side of the non-exit direction, that is, It is sloped upward toward one side so that the side farther away from the side surface 22 where the straight line L intersects is located higher.

Further, a large number of guide ribs 32 are formed on the inner surface of the top surface portion 21. The guide rib 32 is a protrusion that protrudes from the inner surface of the top surface portion 21 and extends along a straight line passing through the outlet 23 in plan view.

FIG. 6 is a diagram showing the relationship between the rib angle α and the inclination gradient β of the top surface portion 21 in the convex portion 31.

The inclination gradient β of the top surface portion 21 in the convex portion 31 is set according to the rib angle α of the guide rib 32. The rib angle α is the angle that the guide rib 32 makes with respect to the non-exit direction (direction along the straight line L), as shown in FIG. The inclination gradient β is the angle that the top surface portion 21 makes with respect to the horizontal plane, as shown in FIG.

The inclination gradient β is set so as not to decrease at least as the rib angle α increases. For example, as shown in FIG. 6, the minimum value of the inclination gradient β is set for each of multiple angle ranges for the rib angle α, and the rib angle is relatively larger than the angle range for the relatively small rib angle α. It is set to increase in the angle range of α. The inclination gradient β is set to a value greater than or equal to the minimum value of the inclination gradient β according to the rib angle α (a value within the shaded area in FIG. 6).

<Effect>
As described above, the top surface portion 21 of the upper case 12 is formed with the outlet 23 through which oil flows out from the filtration chamber 14 between the lower case 13 and the upper case 12. It is sloped so that it is located at Further, a convex portion 31 that is convex toward the filtration chamber 14 side is formed on the top surface portion 21, and in this convex portion 31, an arbitrary point within the convex portion 31 and the outlet 23 pass through the convex portion 31 in a plan view. In the non-exit direction along the straight line L that intersects with the straight line, it is inclined so that one side of the non-exit direction is located higher.

As a result, after the oil pump has stopped, when air bubbles contained in the oil float up inside the oil to the inner surface of the top part 21 outside the convex part 31, the air bubbles flow along the slope of the top part 21 to the outlet. Move towards 23. On the other hand, in the convex portion 31, the bubbles that have floated up to the inner surface of the top surface portion 21 move toward one side in the non-exit direction along the slope of the top surface portion 21, and when they reach the outside of the convex portion 31, the bubbles float to the inner surface of the top surface portion 21. The outside of portion 31 is moved toward outlet 23 .

Therefore, even if the convex portion 31 that protrudes toward the filtration chamber 14 is formed on the top surface portion 21, the generation of air pockets can be suppressed. Moreover, since it is sufficient to eliminate air bubbles from the convex portion 31, the inclination of the top surface portion 21 at the convex portion 31 can be set to a minimum, and an increase in the thickness and volume of the oil strainer 1 can be suppressed.

A guide rib 32 is formed on the inner surface of the top surface portion 21 so as to protrude downward and extend along a straight line passing through the outlet 23 in plan view. Thereby, the air bubbles can be guided toward the outlet 23 along the guide ribs 32 outside the convex portion 31 .

The upward slope β of the convex portion 31 is set for each of a plurality of angular ranges of the rib angle α, and is larger in the angular range of the relatively large rib angle α than in the angular range of the relatively small rib angle α. It is set as follows.

In the convex portion 31 where the top surface portion 21 is inclined upwardly to one side in the non-exit direction, if the rib angle α of the guide rib 32 with respect to the non-exit direction is large, the movement of bubbles toward one side in the non-exit direction is prevented. There is a possibility that the guide rib 32 may obstruct the movement. Therefore, in the portion where the rib angle α formed by the guide rib 32 with respect to the non-exit direction is large, the upward slope β of the top surface portion 21 is set to be large, so that the guide rib 32 can be moved favorably in the non-exit direction. be able to. As a result, the occurrence of air pockets can be further suppressed.

<Modified example>
Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms.

For example, the inclination gradient β may be constant regardless of the rib angle α. However, in that case, it is preferable that the inclination gradient β is set at an angle that allows the bubbles to move in the non-exit direction without being blocked by the guide ribs 32 even at the location where the rib angle α is 90°.

In addition, various design changes can be made to the above-described configuration within the scope of the claims.

1: Oil strainer 12: Upper case (upper member)
13: Lower case (bottom member)
14: Filtration chamber 21: Top part 23: Outlet 31: Convex part 32: Guide rib (rib)
L: Straight line (non-exit direction)
α: Rib angle β: Incline slope (upward slope in convex part)

Claims (2)

a bottom member;
an upper member that abuts against the bottom member from above and forms a filtration chamber between the bottom member and the bottom member;
The upper member has a top part that covers the filtration chamber from above , and a side part that extends downward from a periphery of the top part ,
An outflow port is formed at the top of the top surface portion to allow oil to flow out from the filtration chamber,
The top portion is
It has a convex portion that is convex toward the filtration chamber,
on the outside of the convex portion, the convex portion is inclined upward as it approaches the outlet;
In the convex portion, in a non-exit direction that intersects a straight line passing through an arbitrary point within the convex portion and the outlet in plan view, the side further away from the side surface where the straight line intersects is located higher. tilted ,
A rib is formed on the inner surface of the top surface portion, protruding downward and extending along a straight line passing through the outlet in plan view;
The oil strainer is configured such that the upward slope of the convex portion does not decrease at least as the rib angle formed by the ribs with respect to the non-exit direction in plan view increases . The upward slope of the convex portion is set for each of a plurality of angular ranges of the rib angle, and is larger in a relatively large angular range of the rib angle than in a relatively small angular range of the rib angle. The oil strainer according to claim 1 , wherein the oil strainer is set.

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