JPH0433930Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a suction strainer that filters hydraulic oil in an oil tank and sends it out from an oil feed pipe, and particularly relates to a connection structure with the oil feed pipe.

[Conventional technology]

As shown in FIGS. 3 and 4, a conventional suction strainer of this type includes a suction strainer 1 and a cylindrical filter element 2.
A metal punching cylinder 3 having a plurality of small holes is arranged inside the filter element 2, and covers 4 and 5 are fixed above and below the filter element 2 and the punching cylinder 3.

In the center of the upper cover 4, there is an oil pipe 6.
A joint nut 7 is fixed to be screwed into a male thread 6a formed at the end of the joint nut 7, and the means for fixing the joint nut 7 and the upper cover 4 is to insert the joint nut 7 into the circular hole 4a of the upper cover 4. A short cylindrical portion 8 was inserted, and the short cylindrical portion 8 was bent outward at the lower peripheral edge of the circular hole 4a and fixed.

[Problem that the invention attempts to solve]

However, in the conventional suction strainer 1 as described above, there is a male thread 6a at the end of the oil pipe 6.
When attaching and detaching the suction strainer 1 to the oil feed pipe 6, it is necessary to unscrew the suction strainer 1 from the joint nut 7, that is, to rotate the suction strainer 1 itself. , it cannot be installed and removed easily and quickly, and when connecting it to the oil feed pipe 6, a sealing tape or the like is wrapped around the male threaded part a of the oil feed pipe 6 to prevent leakage. There is a risk that tape scraps or cutting powder from the joint nut 7 and oil feed pipe 6 may enter the filter element 2 and contaminate the clean hydraulic oil, and there is a possibility that the joint nut 7 is fixed to the upper cover 4. That is, since the short cylindrical portion 8 has a structure that protrudes downward from the lower surface of the upper cover 4, a cavity (air pocket) 9 is formed between the short cylindrical portion 8 and the lower surface of the upper cover 4, and this cavity is filled with air. The air in the hydraulic oil will be trapped in the chamber 9, and this air will cause a cavitation phenomenon that will adversely affect the pump.Furthermore, the oil feed pipe 6 and the coupling nut 7 are firmly fixed by screw connection. Therefore, the fixing part 8 between the joint nut 7 and the upper cover 4 becomes the weakest point in terms of structure, and there is a risk that this part of the fixing part 8 may be damaged due to vibration or the like.

[Means for solving problems]

The present invention was developed to solve the conventional problems as described above, and it is easy to attach and detach from the oil pipe, and the structural strength of the oil pipe attachment part is high and the cavitation phenomenon is prevented. The purpose is to provide something that does not occur, and its gist is to insert the end of an oil pipe into the upper opening of a cylindrical filter element, the upper surface of the periphery of which is formed with a horizontal surface, and which hangs down at a right angle in the center. At the same time, a ring-shaped upper cover with a cylindrical part is mounted on the upper cover, and an annular plate with an inclined surface rising from the lower surface of the periphery toward the central oil pipe insertion hole is installed on the upper cover. The O-ring is placed between the surface and the horizontal surface of the upper cover, and the O-ring is pressed against the outer peripheral surface of the oil pipe by fixing the annular plate to the upper cover with bolts from above. The upper cover is configured to be fixed by its frictional force, and an inner flange is formed at the lower end of the cylinder of the upper cover.
The suction strainer is characterized in that a bottom plate extending from the inner flange toward the inner wall of the filter element is formed with an inclined surface rising toward the inner flange.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the embodiments shown in FIGS. 1 and 2. Note that FIG. 1 is a half-cut vertical sectional view of a suction strainer according to the present invention, and FIG. 2 is an exploded perspective view of the main components of the strainer.

In the figure, 1 is a suction strainer, 2
3 is a general-purpose filter element, and 3 is a punching tube disposed inside the filter element 2. The openings at both upper and lower ends of the filter element 2 and punching tube 3 are covered with a ring-shaped upper cover 4 and a disk-shaped lower cover 5, respectively. It is closed and fixed.

Reference numeral 6 denotes a short cylindrical portion formed in the center of the upper cover 4, extending into the filter element 2 and the punching tube 3, and punching from an inner flange portion 7 formed at the lower end of the cylindrical portion 6. The bottom plate 8 extending to the inner wall surface of the cylinder 3 is formed of an inclined surface rising toward the lower end opening of the cylindrical portion 6. Note that 9 in the figure is an oil pipe inserted into the cylindrical portion 6.

Reference numeral 10 denotes an annular plate attached to the upper surface of the upper cover 4. A hole 11 for inserting the oil pipe 9 is formed in the center thereof, and a lower surface 10a is formed at the periphery of the lower surface of this hole 11. Peripheral surface 10b of open hole 11
A slope 12 is formed that rises toward
The inner diameter of this hole 11 is formed to be approximately the same size as the inner diameter of the cylindrical portion 6. In the figure, reference numeral 13 indicates insertion holes for bolts 14, which are formed at positions corresponding to the female screw holes 4b, 4b formed in the upper cover 4, respectively.

Reference numeral 15 denotes an O-ring, which has an inner diameter that is approximately the same size as the outer diameter of the end of the oil pipe 9, and is located between the peripheral upper surface formed on the flat surface of the upper cover 4 and the inclined surface 12 of the annular plate 10. It is to be fitted into the

Therefore, when assembling, first arrange the annular plate 10 on the upper surface of the upper cover 4 via the O-ring 15,
A bolt 14 is inserted through the insertion hole 13 and loosely screwed into the female threaded hole 4a, 4b of the upper cover 4.

Next, insert the end of the oil pipe 9 into the cylindrical part 6 of the upper cover 4 through the central hole 11 of the annular plate 10 until the pipe end 9a of the oil pipe 9 comes into contact with the inner flange part 7. . In this state, when the bolt 14 inserted into the bolt insertion hole 13 is further tightened, the annular plate 10 moves in the direction of the upper cover 4, so that the inclined surface 12 compresses the O-ring 15 and pushes it inward. .

As a result, the O-ring 15 is strongly pressed against the outer circumferential surface of the oil pipe 9, and the suction strainer 1 and the oil pipe 9 are frictionally engaged to be elastically and firmly connected, and are watertight. It becomes a connected structure.

Therefore, the hydraulic oil in the oil tank is filtered by passing from the outside to the inside of the filter element 2 and punching cylinder 3, and then is supplied to predetermined hydraulic equipment etc. through the oil feed pipe 9.
At this time, the upper surface inside the suction strainer 1, that is, the bottom plate 8 of the upper cover 4 is connected to the pipe end 9a of the oil pipe 9.
Since the suction strainer 1 is constructed of an inclined surface that is inclined toward the upper surface of the hydraulic oil in the suction strainer 1, no empty space (air pocket) is formed between the suction strainer 1 and the upper surface of the hydraulic oil.

Also, you can clean the suction strainer 1,
Or, when removing it from the end of the oil pipe 9 in order to replace it with a new one, loosen the bolt 14.
The ring 15 is elastically restored, the pressure on the outer peripheral surface of the oil pipe 9 is released, and the cylindrical portion 6 of the upper cover 4 is released.
The end of the oil pipe 9 can be easily pulled out. At this time, the bolts 14 are not removed from the female screw holes 4b, 4b of the upper cover 4, and the annular plate 10
All you have to do is loosen the pressure.

[Effect of idea]

As described above, the suction strainer according to the present invention includes a cylindrical part in which the upper opening of the cylindrical filter element has a horizontal upper peripheral edge surface, and the end of the oil pipe hanging at right angles is inserted into the center of the cylindrical filter element. At the same time, a ring-shaped upper cover is mounted on the upper cover, and an annular plate having an inclined surface rising from the bottom surface of the periphery toward the hole for inserting the oil pipe in the center is attached to the upper cover. The annular plate is arranged via an O-ring installed between the horizontal surface and the annular plate is fixed to the upper cover with bolts from above, so that the O-ring is pressed against the outer circumferential surface of the oil pipe and the friction force is used. Since it is configured to be fixed, it can be attached and detached from the filter element of the oil pipe by simply pressing and releasing the annular plate, and the attachment and detachment work can be carried out easily and quickly.

Moreover, since the oil pipe is not threadedly connected to the oil pipe as in the past, there is no risk of cutting metal powder or sealing tape debris entering the filter element and mixing with the hydraulic oil. The O-ring absorbs vibrations and prevents damage to the cover.

Further, an inner flange portion is formed at the lower end of the cylinder of the upper cover, and a bottom plate extending from the inner flange portion toward the inner wall of the filter element is formed with an inclined surface rising toward the inner flange portion. With this structure, air pockets do not form on the top surface of the hydraulic oil inside the filter element.
This has various effects such as being able to prevent pressure loss in the oil fluid due to air bubbles trapped in the air pool, as well as preventing adverse effects on the pump.

[Brief explanation of the drawing]

Fig. 1 is a half-cut longitudinal sectional view of a suction strainer according to the present invention, Fig. 2 is an exploded perspective view of the main components of the strainer, Fig. 3 is a half-cut longitudinal sectional view of a conventional suction strainer, and Fig. 4 is a longitudinal sectional view of a conventional suction strainer. The figure is a partially enlarged sectional view of the same strainer. DESCRIPTION OF SYMBOLS 1... Suction strainer, 2, 3... Filter element, 4... Upper cover, 6... Cylindrical part, 7... Inner flange part, 8... Inclined bottom plate, 9
... Oil pipe, 10 ... Annular plate, 11 ... Hole, 12
... Inclined surface, 13 ... Bolt insertion hole, 14 ... Bolt, 15 ... O-ring.

Claims (1)

[Claims for Utility Model Registration] (1) A ring-shaped filter element having a cylindrical part in which the upper opening of the cylindrical filter element is formed with a horizontal upper surface and a cylindrical part in the center into which the end of an oil pipe hanging at right angles is inserted. At the same time as the upper cover is attached, an annular plate having an inclined surface rising from the bottom surface of the periphery toward the central oil pipe insertion hole is placed on the upper cover so that the inclined surface and the horizontal surface of the upper cover are connected to each other. By fixing the annular plate to the upper cover with bolts from above, the O-ring is pressed against the outer peripheral surface of the oil pipe and fixed by the frictional force. A suction strainer characterized by the following structure. (2) An inner flange is formed at the lower end of the cylinder of the upper cover, and a bottom plate extending from the inner flange toward the inner wall of the filter element is formed with an inclined surface rising toward the inner flange. The suction strainer according to claim 1, characterized in that the suction strainer is formed of a suction strainer.