JPS6335768Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention mainly relates to a filter device used in a hydraulic circuit of a construction machine.

Conventionally, an oil filter as shown in FIG. 1 has been used in hydraulic circuits of construction machines and the like. This oil filter has an element b inside a cylindrical case a.
case a from inside the inlet port c.
The oil flowing into the element b is filtered as it passes through the element b, and the filtered oil is circulated through the outlet port d to the hydraulic circuit. In addition, in order to clean or replace element b when it becomes clogged, a cover e that can be opened and closed is provided at the top of case a, but before removing element b, drain the oil in case a to drain port f. If the oil is not extracted from the outlet port d, the oil that has not been filtered by the element b will reach the outlet port d.
There is a risk that the oil may flow into the hydraulic circuit and damage various hydraulic equipment in the hydraulic circuit. Therefore, in the past, before removing the cover e, the plug g of the drain port f was removed to drain the oil inside the case a, which had the drawback of requiring a lot of effort to clean and replace the element b.

This invention was made with the purpose of eliminating such drawbacks, and it provides a filter device that drains the oil inside the case when the cover is removed to take out the element, making it easy to clean and replace the element. It was designed so that it could be done.

This invention will be described in detail below with reference to an embodiment shown in FIG.
However, an outlet port 3 is provided above and a drain port 4 is provided at the bottom. Reference numeral 5 denotes an element housed in the case 1, whose upper end is inserted into the lower surface of the cover 6 inserted into the opening of the case 1, and the lower end of the bolt 7 screwed into the center of the lower surface of the cover 6. The cover 6 is clamped between the cover 6 and the seat plate 8 by tightening a drain valve 9 which is provided between the cover 6 and the seat plate 8 and screwed into the lower end of the bolt 7. The drain valve 9 has an O-ring 10 on the outer periphery of the lower end,
It is fitted into the drain port 4 in a fluid-tight manner. A partition wall 6c is provided in the cover 6 to separate a passage 6a communicating with the inside of the element 5 and a passage 6b communicating with the outside. 6d is open.

The bypass valve 11 is always urged upward by a compression spring 12 in a spring chamber 6e formed at the center of the lower part of the cover 6 to close the through hole 6d. When the pressure becomes negative, it is opened and the oil in the case 1 is bypassed to the outlet port 3 side without passing through the element 5.

Note that 13 is a drain hose connected to the drain port 4.

Since this device is as described in detail above, when the element 5 becomes clogged and the cover 6 is removed to clean or replace it, the drain valve 9 connected to the cover 6 through the bolt 7 is connected to the drain port. 4 to drain the oil in case 1 from drain port 4, remove the drain plug each time and open case 1.
There is no need to drain the oil inside, and the element 5 can be cleaned and replaced in a short time. Furthermore, since the element 5 can be removed together with the cover 6, there is no need to worry about staining hands or clothes with oil.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional filter device, and FIG. 2 is a sectional view of a filter device according to an embodiment of the present invention. 1 is a case, 2 is an inlet port, 3 is an outlet port, 4 is a drain port, 5 is an element, 6 is a cover, 7 is a bolt, and 9 is a drain valve.

Claims (1)

[Scope of utility model registration request] The above-mentioned opening of the case 1, which has an inlet port 2 and an outlet port 3 on the outer periphery and a drain port 4 on the bottom, is closed with a cover 6 having an element 5 attached to the lower surface. A filter device in which a drain valve 9 for closing a drain port 4 is attached to the tip of a bolt 7 to which a drain valve 5 is attached.