JPS6310806Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a filter element for machining oil in an electric discharge machine for machining metal materials.

As is well known, machining oil is used when electrical discharge machining metal materials, and during machining, the machining oil is circulated and supplied, and the sewage containing machining chips is led to the sewage tank from the drain port. A part of the cleaning liquid is precipitated and then pumped up by the filter circuit pump and sent to the filter device, and the cleaning liquid discharged from the filter device is collected in the cleaning liquid tank and continuously overflows to the stock solution tank.

As shown in Fig. 1, the above-mentioned filter device has an inlet 1 for dirty liquid and an outlet 2 for supercleaned liquid.
It consists of a filter element 4 mounted in the filter chamber 3 and a cap 5 and a spring 6.
It is clamped and fixed in the overchamber 3 by. This filter element 4 is provided with a filter sheet 7 bent into a bellows shape and formed into a cylindrical shape on the outer periphery, and has a cage pipe 9 provided with a large number of pores 8, 8 inside, and the filter sheet The upper and lower ends of the filter element 7 are fixed to the inner surfaces of the upper and lower flanges 10 and 11 with adhesive, and the above-mentioned dirty liquid flows from the outside of the filter element 4 and is passed through the bellows-shaped filter sheet 7. It passes through the cage pipe 9 and is sent from the outlet 2 to a cleaning liquid tank (not shown).

The filter sheet 7 in the conventional filter element 4 is formed by bending a cardboard-like sheet material made of wet-laid nonwoven fabric, that is, cellulose fiber, into a bellows shape to form a cylinder with a desired outer diameter. , 11 so as to be sandwiched between them. However, when the filter sheet 7 is made of a cardboard-like sheet material made of cellulose fibers, the filter sheet 7 has the advantage of being inexpensive, but it is easily swollen during overheating and is difficult to process. When overperformance is reduced due to clogging with chips or powder, it is difficult to clean the clogging and reuse is almost impossible. Furthermore, as mentioned above, since the filter element 4 is mounted with pressure inside the filter chamber 3, this pressing force is applied to the upper and lower flanges 1.
Since the filter sheet 7 is also loaded through the filters 0 and 11 and the pressing elasticity is quite large, the filter sheet 7 is distorted and deformed during use, which also makes it impossible to reuse it.

Therefore, the conventional filter element 4 is recognized as a disposable type and is actually discarded after use.

The present invention improves the above-mentioned disadvantages of the conventional filter element, provides durability against external forces in the filter chamber, and is used in electrical discharge machines that can be used repeatedly by cleaning when clogged. A filter element for a filter device is provided, in which the above-mentioned bellows-shaped filter sheet 7 is made into a pseudo-leather-like shape by pressing a nonwoven fabric of synthetic resin continuous filaments, such as polyester continuous filaments, obtained by spunbonding. It is made of sheet material that has been made into a shape, and after being pleated into a bellows shape.
As shown in the figure, both end portions 7a and 7b are polymerized and bonded 12 to form a cylindrical shape, and the joined portion is held between metal plates 13 having a hairpin shape in cross section, and the pleated portion 7c of the cylindrical filter sheet 7 is A metal plate 1 with a V-shaped cross section is placed at several places on the
The filter sheet 7 and the metal plates 13, 14 are fixed to the inner surfaces of the upper and lower flanges 10, 11 at their upper and lower ends with the filter sheet 7 and the metal plates 13, 14 overlapped. As for this fixing means, it is preferable to use an adhesive for the filter sheet 7 and to use welding for the metal plates 13 and 14.

As described above, in the filter element 4 for machining oil in the electrical discharge machine of the present invention, the filter sheet 7 having the bellows-shaped pleated portions 7c forming the filter is made of a spunbond nonwoven fabric made of continuous filament of synthetic resin. Therefore, it does not become soft when exposed to processing oil, and therefore, it can be used repeatedly once the clogging is cleaned, making it extremely economical. Furthermore, both ends 7a and 7b of the cylindrical filter sheet 7 are polymerized and bonded, and the joint is held between metal plates 13 having a hairpin shape in cross section, so that the external pressure of the machining oil during overload can be avoided. This prevents the joint from being damaged, and furthermore, since the metal plates 14, 14, each having a V-shaped cross section, are in close contact with the pleats 7c of the filter sheet 7, the tube can be opened by the pressure of the machining oil. This prevents the filter sheet 7 from being deformed. Furthermore, since the upper and lower ends of the metal plates 13 and 14 are fixed to the inner surfaces of the upper and lower flanges 10 and 11, as well as the upper and lower ends of the filter sheet 7, the pressure resistance in the axial direction is increased, and the pressure inside the overchamber 3 is increased. It is particularly suitable for overuse of machining fluid in electric discharge machines, as it can sufficiently withstand pressure fixing force and does not cause distortion even after repeated long-term use.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a filter device for processing oil, and FIGS. 2 to 4 show examples of the filter element of the present invention.
The figure is a partially sectional perspective view, FIG. 3 is a sectional view taken along the line A--A in FIG. 2, and FIG. 4 is a sectional view of the flange portion. 4 is a filter element, 7 is a filter sheet, 7a and 7b are both ends of the filter sheet,
7c is a pleat part, 10 and 11 are upper and lower flanges, 13 is a metal plate with a hairpin-shaped cross section, 1
4 is a metal plate with a V-shaped cross section.

Claims (1)

[Scope of utility model registration request] A filter element 4 in which a cylindrical filter sheet 7 having bellows-like pleats is wrapped around the outer periphery between upper and lower flanges 10 and 11,
The filter sheet 7 is made of a spunbond nonwoven fabric made of continuous filament of synthetic resin, and the polymerized bonded portions of both ends 7a and 7b are held together by metal plates 13 having a hairpin shape in cross section, and the pleats 7c have a cross section of V at several places. Letter-shaped metal plate 1
4 and 14 are in close contact with each other, and the upper and lower ends of the filter sheet 7 and the metal plates 13 and 14 are fixed to the inner surfaces of upper and lower flanges 10 and 11, respectively.