JPH07241418A - Filter for collecting iron powder in fluid - Google Patents

Abstract

PURPOSE:To provide a filter for collecting iron powder in fluid whose magnet crack property and iron powder collecting effect are improved. CONSTITUTION:A filter for collecting iron powder 1 is composed of a holder 10 and a resin magnet part 2. The holder 10 consists of a back plate part 11 formed extendingly in the shape of a flange, and a shaft part 12 provided successively and coaxially with the back plate part 11. The resin magnet part 2 is formed of a mixture of rare earth magnet powder and resin, and is stuck to the back plate part 11. By fitting the shaft part 12 to a free piston 3 of a shock absorber, the free piston 3 is equipped with the filter 1 for collecting iron powder. The filter for collecting iron powder 1 is used by immersing it into oil in which iron powder is mixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter for collecting iron powder in a fluid. This iron powder collecting filter can be applied to parts using oil such as a shock absorber of a vehicle.

[0002]

2. Description of the Related Art Conventionally, a ring projection 1 for partitioning a central hole 100 as shown in FIG.
Holder 10 with back plate part 102 having 01
3, a small diameter columnar sintered rare earth magnet portion 105 is fixed to the bottom surface 100a of the central hole 100 of the ring protrusion 101 with an adhesive, and an aluminum washer 107 is attached to the sintered rare earth magnet portion 105 for positioning. Those fitted around are known. This iron powder collecting filter is used by immersing it in oil. The iron powder contained in the oil is the sintered rare earth magnet part 10
5 is adsorbed and collected.

Generally, a sintered rare earth magnet portion 105 is used.
Has low impact resistance and is brittle, so the sintered rare earth magnet portion 105 is not exposed to the outside of the ring-shaped protrusion 101, and the sintered rare earth magnet portion 105 is surrounded by the ring-shaped protrusion 101 to ensure protection. is doing. As described above, since the sintered rare earth magnet portion 105 is not exposed to the outside of the ring-shaped protrusion 101, and the sintered rare earth magnet portion 105 is considerably smaller than the diameter of the back plate portion 102, the iron The powder collection effect was insufficient.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide an iron powder trapping filter in a fluid having improved magnet cracking properties and iron powder trapping effect. It is in.

[0005]

The iron-in-fluid powder collection filter of the present invention is formed of a yoke material, and is provided substantially coaxially with a back plate portion extending in a flange shape and one surface of the back plate portion. And a resin magnet part fixed to the plate surface of the back plate part of the holder facing the shaft part and formed of a mixed material of rare earth magnet powder and resin. It is characterized by being present.

Generally, permendur or soft magnetic stainless steel having a high saturation magnetic flux density can be used as the yoke material constituting the holder. The shaft portion of the holder portion can be fixedly or detachably held to a main body such as a free piston. It is preferable that the back plate part of the holder has an engaging part formed of at least one of concave and convex on the plate surface. In this case, the resin magnet part engages with the engaging part,
The holding property of the resin magnet portion is improved. The engagement portion may be formed in a ring shape coaxially with the back plate portion or the shaft portion, or may be formed non-coaxially, for example, in a linear shape.

The plane shape of the back plate portion and the plane shape of the resin magnet portion can be made to correspond to each other. The resin magnet part
It can be magnetized in a direction perpendicular to the plate surface of the back plate portion. The resin magnet portion is formed of a mixed material composed of rare earth magnet powder and resin. As the rare earth magnet powder, neodymium-iron-boron system, samarium-iron system, etc. can be adopted. Polyamide, nylon, etc. can be adopted as the resin.

[0008]

Since the resin magnet portion contains the resin, impact resistance is improved as compared with the sintered magnet. Since the resin magnet portion is directly exposed in the fluid, iron powder in the fluid is easily collected by the resin magnet portion. When the engagement portion is formed, the engagement between the resin magnet portion and the holder is improved.

[0009]

Embodiments of the present invention will be described below with reference to FIGS. This iron powder collecting filter 1 is composed of a holder 10 and a resin magnet portion 2. The holder 10 includes a back plate portion 11 extending in a disc flange shape and a shaft portion 12 coaxially connected to the back plate portion 11. The holder 10 is made of carbon steel.

The resin magnet portion 2 is in the form of a thin sheet, and is fixed to a plate surface 11c, which faces the shaft portion 12 of the back plate portion 11 of the holder 10. In the resin magnet part 2, with the holder 10 placed in the cavity of the injection mold,
It is formed by injection molding a mixed material composed of rare earth magnet powder and resin into a cavity. The rare earth magnet powder is a neodymium-iron-boron system, and the resin is nylon.

The planar shape of the resin magnet portion 2 is made to correspond to the planar shape of the back plate portion 11. The resin magnet portion 2 is magnetized in a direction perpendicular to the plate surface 11c of the back plate portion 11, one surface 2a of the resin magnet portion 2 is the N pole, and the other surface of the resin magnet portion 2 on the shaft portion 12 side is the other surface. Two
b is the south pole. The outer diameter D1 of the back plate portion 11 is about 10 mm, the thickness t1 is about 2 mm, and the shaft portion 1 is
The outer diameter D2 of 2 is about 6 m, and the thickness t2 of the resin magnet portion 2 is 1
It is about mm.

As shown in FIG. 3, the shaft portion 12 of the holder 10 is
Is attached to the mounting hole 30 of the free piston 3 as the main body, so that the iron powder collecting filter 1 is mounted on the free piston 3. Reference numeral 32 is a ring-shaped seal held on the outer peripheral portion of the free piston 3. The iron powder collecting filter 1 described above is used by immersing it in oil mixed with iron powder.

In this embodiment, since one side 2a of the resin magnet portion 2 is directly exposed to the oil during use, the magnetic flux density in the collecting area can be increased, and the iron powder in the oil is collected in the resin magnet portion 2. It is easy to be beaten. Further, since the resin magnet portion 2 has impact resistance unlike the sintered magnet, it has a disk shape with a large diameter, and also in this sense, the iron powder collecting effect is high. 4 to 6 show examples of a magnetized form on one surface 2a of the resin magnet portion 2. The magnetization state on the other one surface 2b of the resin magnet portion 2 is the opposite.

In the example shown in FIG. 7, the engaging portion 1 having a convex shape on the plate surface 11c of the back plate portion 11 of the holder 10.
Forming 7. The engagement portion 17 is formed in a ring shape coaxially with the axis of the shaft portion 12, and has an inclined surface 17a and an inclined surface 17b. Therefore, the inclined surface 17a and the inclined surface 17b
Is a conical surface coaxial with the axis of the shaft portion 12. In this example, the resin magnet portion 2 engages with the engaging portion 17, and the integral holding property of the resin magnet portion 2 is improved.

The example shown in FIG. 8 also has basically the same configuration as the example shown in FIG. 7, and accordingly, a convex engaging portion 17 is formed on the plate surface 11c of the back plate portion 11 of the holder 10. . Also in this example, the effect of improving the integral holding property can be obtained. FIG. 9 shows an application example applied to the shock absorber 5 of the vehicle. As shown in FIG. 9, the above-mentioned free piston 3 is mounted on the lower portion of the cylindrical outer shell 50. The free piston 3 is a gas chamber 5 filled with gas.
2 and the oil chamber 53 in which the oil 53a is enclosed. A cylindrical inner shell 55 is provided inside the outer shell 50, and a base valve 56 is provided at the end of the inner shell 55. A piston valve 59 is provided at the lower end of the piston rod 58 inserted in the inner shell 55.

Although the above example is applied to the shock absorber, the present invention is not limited to this and can be applied to equipment such as various hydraulic materials.

[0017]

According to the iron-in-fluid powder collecting filter of the present invention, the magnetic flux density in the collecting region can be increased, and the iron powder in the fluid is easily collected in the resin magnet portion. Further, unlike the sintered magnet, the resin magnet portion has impact resistance, which is advantageous in setting a large area unlike the sintered magnet, and in this sense, the iron powder collecting effect is high.

If the back plate portion of the holder has an engaging portion formed of at least one of a concave portion and a convex portion, the resin magnet portion engages with the engaging portion. The holding property is improved and the detachment of the resin magnet part can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of an iron powder collection filter.

FIG. 2 is a vertical sectional view of an iron powder collecting filter.

FIG. 3 is a vertical cross-sectional view showing a mode in which an iron powder collection filter is used.

FIG. 4 is a plan view showing another magnetized form.

FIG. 5 is a plan view showing another magnetized form.

FIG. 6 is a plan view showing another magnetized form.

FIG. 7 is a vertical cross-sectional view of an iron powder collecting filter having an engaging portion.

FIG. 8 is a vertical cross-sectional view of an iron powder collecting filter having another engaging portion.

FIG. 9 is a vertical sectional view of an application example.

FIG. 10 is a vertical sectional view of a conventional example.

[Explanation of symbols]

 1: Iron powder collection filter 11: Back plate part 11c: Plate surface 12: Shaft part 10: Holder 2: Resin magnet part 17: Engagement part

Claims (2)

[Claims] 1. A holder comprising a back plate portion formed of a yoke material and extending in a flange shape, and a shaft portion substantially coaxially connected to one surface of the back plate portion, and a back plate of the holder. Iron powder trapping filter in a fluid, characterized in that it is fixed to a plate surface of the shaft portion facing the shaft portion and is composed of a resin magnet portion formed of a mixed material of rare earth magnet powder and resin. . 2. The back plate part of the holder has an engaging part formed of at least one of concave and convex on the plate surface, and the resin magnet part is engaged with the engaging part. The iron powder collecting filter in fluid according to 1.