JPH0430403Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a suction filter device, and more particularly to an improvement in a suction filter device suitable for use in filtering and pumping up hydraulic oil in an oil tank of a hydraulic circuit of a vehicle automatic transmission.

[Conventional technology]

Generally, a filter is attached to a vehicle's hydraulic control device to filter drain that has returned into an oil tank via various oil passages and then send it back to the oil passage. This type of suction filter device is usually installed in an oil tank of a hydraulic control device at the inlet of a suction pipe that pumps up hydraulic oil from the oil tank.
A housing having an opening in the hydraulic fluid, and a filter disposed to cover the opening of the housing, wherein the hydraulic fluid that has passed through the filter flows from the suction port located above the filter. It is designed to be inhaled. In recent years, as the performance of vehicles has improved, precision hydraulic control parts are used, especially in the hydraulic control devices that operate belt-type continuously variable transmissions, so minute impurities in oil can be removed with higher precision than before. Since it has become necessary to do this, the filter is made to have a fine mesh of, for example, about 50 microns.

[Problem that the idea aims to solve]

However, when a fine-mesh filter is used in this way, when air bubbles that are generated in the oil passage or mixed in the oil passage in the transmission pass through the filter, the fine mesh makes it difficult for the filter to move smoothly. There was a problem that air bubbles could not pass through the filter surface and air bubbles were likely to accumulate on the filter surface. In other words, when a certain amount of bubbles of this kind have accumulated, if the bubbles are sucked out by the hydraulic pump all at once,
The problem is that so-called cavitation occurs in the hydraulic pump, causing problems such as abnormal noise and unstable line pressure. Conventionally, as a suction filter device designed to remove a certain amount of air bubbles generated or mixed in the oil passage, for example, the
123575, a relatively fine main filter disposed to cover the opening of the housing, and an oil passage in the hydraulic control device connected to the lower part of the oil tank above the main filter. There is a suction filter device that is equipped with a relatively coarse intermediate filter interposed between the filters, but this type of suction filter device requires two stages of filters, has a complicated structure, and is expensive to manufacture. There was a new problem:

[Purpose of invention]

The present invention has been developed in view of these conventional problems, and has a simple structure that removes air bubbles that are generated in or mixed into the oil passage in the hydraulic control device and returns them to the hydraulic pump side. The suction filter device is capable of efficiently discharging air bubbles out of the hydraulic control device without suctioning them into the air, thereby eliminating problems such as noise generation and unstable line pressure caused by air bubble suction. The purpose is to provide.

[Means to solve the problem]

The present invention provides a suction filter device that pumps hydraulic oil containing air bubbles in an oil tank of a hydraulic control device to the upper part of the oil tank while removing the air bubbles. an inlet of a suction pipe located above the filter, which inhales the hydraulic oil after passing through the filter from below to above; and when the hydraulic oil passes through the filter, The above object is achieved by providing a passageway for removing air bubbles collected at the top of the mountain to the outside of the tank.

[Effect]

In the present invention, we focused on the fact that air bubbles in oil tend to collect on the somewhat inclined part of the filter surface (the part that protrudes toward the suction pipe side), and we designed a filter that actively protrudes toward the suction pipe side. The mountain part for collecting air bubbles is formed at a position horizontally offset from the suction port, and a passage for removing air bubbles to the outside is opened and arranged at the apex of this mountain part. The air bubbles are collected at the apex portion of the peak by the buoyancy of the air bubbles and the flow of the pumped hydraulic oil, and then the collected air bubbles can be immediately and automatically discharged to the outside through the passage. As a result, when the air bubbles in the oil return to the oil tank, they are discharged outside the hydraulic control device without being returned to the oil, resulting in abnormal noises caused by the air bubbles and unstable line pressure. can solve the problem.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. 1 and 2 show a first embodiment of the present invention. In this embodiment, an oil tank 10 in a hydraulic control device
provided at the suction port 140 of the suction pipe 14 for pumping up the hydraulic oil 12 from the oil tank 10 in the interior;
A suction filter device comprising a housing 16 having an opening 160 in the hydraulic fluid 12 and a filter 18 disposed to cover the opening 160 of the housing 16. A ridge 180 for collecting air bubbles protruding toward the suction pipe 14 side is formed at a position horizontally offset from the suction port 140, and a ridge 180 for collecting air bubbles Ar is formed at a position horizontally offset from the suction port 140. The passage 22 is opened and arranged at the apex portion 180A of this mountain portion 180. The housing 16 is a flat container with a substantially rectangular plane, and has a folded flange portion 161 at the bottom.
and an extended bottom portion 162. An opening 160 facing into the hydraulic oil 12 is opened at the center of the bottom. The housing 16 is connected to the vicinity of the suction port 140 of the suction pipe 14 at the center of its upper portion 163. The entire circumference of the filter 18 is held between the folded flange portion 161 of the housing 16 and the opening flange portion 22 of the passage 22.
By being fixed to 0, the pyramid-shaped peak 180
is formed. This filter 18 has approximately 50
Extremely fine grains on the order of microns are used. Note that it is preferable to make a slightly larger hole in the apex portion 180A of the mountain portion 180 of the filter 18 so that air bubbles can be smoothly discharged. The passage 22 is located in the upper part 163 of the housing 16.
The upper part 163 of the housing 16 is fixed to the housing 16 at a position shifted from the center position by a distance L in the longitudinal direction of the rectangle (offset position). The lower opening has an opening flange portion 22.
0 is formed, and the filter 18 is fixed to this opening flange portion 220 as described above. The exterior 20 of this passage 22 is open to the atmosphere. In addition, in the figure, the reference numeral 24 indicates a hydraulic pump. Next, the operation of this first embodiment will be explained. When the hydraulic pump 24 operates, its suction force creates a negative pressure inside the suction pipe 14 and the housing 16, and the hydraulic oil 12 in the oil tank 10 is pumped up through the filter 18. At this time, since the mesh of the filter 18 is extremely fine, air bubbles Ar mixed into the hydraulic oil 12 are removed by the filter 18.
, and is collected along the slope 180B of the mountain portion 180 to the apex portion 180A. However, since a passage 22 for discharging the collected air bubbles Ar to the outside 20 is opened and arranged in the apex portion 180A, the air bubbles Ar thus collected go directly to the outside 20 via this passage 22. It is something that is discharged. Since the apex portion 180A and the suction port 140 are offset in the horizontal direction, the suction of hydraulic oil and the discharge of air bubbles Ar can be simultaneously achieved without any problem. Next, a second embodiment of the present invention will be described using FIGS. 3 and 4. In this second embodiment, a passage 30 is added to the device of the first embodiment to make it easier to discharge air bubbles Ar, and the number of pyramidal peaks 320 formed on the filter 32 is two. Accordingly, a larger filtration area can be secured in the same housing 16. The attached passage 30 is provided at a position symmetrical in plane with the position of the passage 34, which is similar to the passage 22 in the first embodiment, and the filter 32 can be held more easily than in the first embodiment. In addition, since the arrangement of the filter 32 is symmetrical, the hydraulic oil 12 flows onto the slope 3 of the mountain portion 320 of the filter 32 during suction.
Even if 21 is pressed, the housing rotational moments generated thereby cancel each other out, resulting in a statically and dynamically more stable structure. Since the other configurations and functions are the same as those of the first embodiment, the same parts will be referred to in the figures and repeated explanation will be omitted. Next, a third embodiment of the present invention is shown in FIGS. 5 to 7. In this third embodiment, as is clear from FIG. 7, the peaks 400 of the filter 40 are not shaped like a pyramid but are formed into a wave shape. Therefore, the passage 42 is also correspondingly formed into a flat shape extending in a direction perpendicular to the longitudinal direction of the rectangle. In this way, when the peak portion 400 is formed by forming the filter 40 into a wave shape, manufacturing variations in the filter 40, the passage 42, etc. may be easily absorbed. Since the other configurations and operations are the same as those in the previous embodiment, similar parts in the figures are designated by the same reference numerals, and redundant explanation will be omitted. In the above embodiment, the shape of the housing is rectangular, but the present invention does not limit the shape of the housing; for example, the planar shape thereof may be circular. Further, the method of forming the mountain portion of the filter is not limited to the shape of the above embodiment, and may be shaped like an outer ring around a caldera, for example. However, in that case, it is necessary to make the bubble discharge passage into a shape that follows the shape of the mountain portion.

[Effect of the idea]

As explained above, according to the present invention, the air bubbles accumulated on the filter surface can be quickly and automatically discharged to the outside with a simple configuration, and therefore, the generation of abnormal noise due to air bubble suction and line pressure loss can be avoided. An excellent effect can be obtained in that problems such as stability can be resolved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a first embodiment of a suction filter device according to the present invention, FIG. 2 is a sectional view taken along the line shown in FIG. 1, and FIG.
A plan view corresponding to Fig. 1 showing the embodiment, Fig. 4 is a plan view equivalent to Fig. 3.
5 is a plan view corresponding to FIG. 1 showing the third embodiment of the present invention, FIG. 6 is a sectional view taken along the line of FIG. FIG. 3 is a perspective view showing the shape of a filter in a third embodiment. 10...Oil tank, 12...Hydraulic oil, 14...
Suction piping, 140... Suction port, 16... Housing, 160... Opening, 18, 32, 40... Filter, 180, 320, 400... Mountain part, 18
0A...Apex part, 20...External, Ar...Bubble,
22, 30, 34, 42... passage, 24... hydraulic pump.

Claims (1)

[Claim for Utility Model Registration] In a suction filter device that pumps up the hydraulic oil containing air bubbles in the oil tank of a hydraulic control device to the upper part of the oil tank while removing the air bubbles, there is provided a mountain for collecting air bubbles that protrudes upward. a filter having a section, an inlet of a suction pipe located above the filter, through which the hydraulic oil passes through the filter from below to above, and is inhaled; A suction filter device comprising: a passage for extracting air bubbles collected at the top portion of the mountain portion to the outside of the tank when the suction filter is removed.