JPH01281160A - Electric oil filter - Google Patents

Abstract

PURPOSE:To contrive the efficient collection of carbon particles by providing positive and negative electrodes to which a high direct current voltage is applied and which are oppositely located on each side of a filter membrane having holes whose diameter is so sized as to separate carbon articles and filtrating oil through the filter membrane from the positive to the negative electrode sides. CONSTITUTION:A positive electrodes 3 and negative electrode 4 to both of which a high direct current voltage is applied are oppositely located on each side of a filter membrane 8 having holes whose diameter is so sized as to separate carbon articles and oil is filtrated through the filter membrane 8 from the side of the positive electrode 3 to the side of the negative electrode 4, whereby the carbon particles in the oil is collected by an electrostatic force produced by the high direct current voltage and separated by the filter membrane for removal, resulting in a substantial improvement of the filtration efficiency for the capturing of the carbon particles.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an electric oil filter.

(Prior Art and Problems) Internal combustion engines such as automobiles are equipped with oil filters to filter oil.

However, conventional oil filters have a structure in which dust-containing oil is passed through a filter medium to physically collect dust, so the filtering efficiency of particularly fine carbon particles has been low.

For this reason, oil filters with higher filtration efficiency have been required for diesel engines with a large amount of carbon in the oil.

An object of the present invention is to provide an oil filter that can efficiently collect carbon particles.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a separation membrane having a pore size capable of separating carbon particles, and a positive electrode and a negative electrode to which a DC high voltage is applied are disposed facing each other on both sides of the separation membrane. This allows oil to permeate from the positive electrode side to the negative electrode side of the separation membrane.

(Function) In the electric oil filter configured as described above, when oil permeates through the separation membrane, carbon particles in the oil are negatively charged by the negative electrode and attracted to the positive electrode, and the remaining carbon Since the particles are prevented from flowing out by the separation membrane, carbon particles can be removed with high efficiency.

(Example) An example of the present invention will be described below based on the drawings. FIG. 1 shows a longitudinal section of an electric oil filter 1 according to a first embodiment. This oil filter 1 has a cylindrical insulating case 2 with a bottom, and inside the case 2, an outer cylinder electrode 3 serving as a positive electrode and an inner cylinder electrode 4 serving as a negative electrode are arranged concentrically at a predetermined interval. It is located in The open end of the case 2 is closed by an end plate 5, and oil is allowed to flow in and out through an inlet hole 6 and an outlet hole 7 formed in the end plate 5. The outer peripheral surface of the inner tube electrode 4 is completely covered with the separation membrane 8, and the oil that has flowed between the outer tube electrode 3 and the inner tube electrode 4 permeates the separation membrane 8 and flows inside the inner tube electrode 4.
Thereafter, it exits from the case 2 through the exit hole 7.

The structure of each part will be explained in more detail below.

A flange portion 2a is formed at the open end of the case 2, and the flange portion 2a and the peripheral edge portion 5a of the end plate 5 are oil-tightly fastened by a plurality of bolts 12 and nuts 13. Note that a seal ring 14 is disposed on the contact surface between the flange portion 2a and the peripheral edge portion 5a.

The outer cylindrical electrode 3 is fitted onto the inner peripheral surface of the case 2 and connected to a bolt terminal 15 inserted into the end plate 5. On the other hand, the inner cylinder electrode 4 is arranged near the center of the case 2.

One end of this inner cylindrical electrode 4 is connected to a bolt terminal 16 passed through the center of the bottom wall 2b of the case 2, and the other end is crimped to a rubber plate 17 disposed around the outlet hole 7 of the end plate 5. . A large number of small holes 18 are formed in the inner cylinder electrode 4, and the oil that has permeated the separation membrane 8 passes through the small holes 18.

The separation membrane 8 covering the outer peripheral surface of the inner tube electrode 4 is made of, for example, a Teflon membrane. Since this Teflon membrane has minute pores, it can filter and separate carbon particles in the oil. The pore diameter of the Teflon membrane is usually about 0.5 to 3 tones, which is practical. As the separation membrane, it is also possible to use a glass fiber or nitrocellulose membrane in addition to a Teflon membrane.

The electric oil filter 1 is constructed as described above, and the two volt terminals 15 and 16 are connected to the DC high voltage generator 19, and the input voltage from the battery 20 is boosted to, for example, about IKv, and the positive voltage is applied to the outer cylinder electrode 3. When a negative voltage is applied to each inner tube electrode and oil is introduced into the case 2 from the inlet hole 6 in this state, most of the carbon particles in the oil are attracted to the outer tube electrode 3 side, and the remaining carbon The particles are filtered and separated by a separation membrane 8. That is, since the minute MJII 8 is negatively charged, the carbon particles floating around the separation membrane 8 acquire a negative charge, become negatively charged, and are attracted to the outer cylindrical electrode 3 side by Coulomb force. A part of the sucked carbon particles adheres to the inner peripheral surface of the outer cylinder electrode 3 and is captured, and the rest forms a so-called concentrated layer of carbon particles in the vicinity of the outer cylinder electrode 3.

As described above, the electric oil filter 1 according to the present invention removes carbon particles using a combination of electrostatic force and the separation membrane 8, and therefore has excellent filtration efficiency.

Next, an experiment conducted to confirm the effects of the present invention will be described. FIG. 2 shows a longitudinal section of the device 23 used in this experiment. The device 23 has a positive electrode plate 25, a separation membrane (Teflon membrane) 26, and a negative electrode plate 27 arranged in a vertical cylindrical case 24 from above. The space between the positive electrode plate 25 and the separation membrane 26 is slightly wide so that the concentrated layer can be stored (in this case, 5
m■) Leave it open. A large number of small holes 28 are formed in the electrode plates 25 and 27 so that oil can pass therethrough. A vacuum pump 30 is connected to the oil reservoir 29 below the negative electrode plate 27 so that the oil reservoir 29 can be depressurized as needed. The table below shows the results of examining the filtration efficiency by pouring the waste oil 32 onto the positive electrode plate 25 using such a device 23.

table *The above insoluble matter is before filtration.

The left column in the table shows the experimental results in which the electrode plates 25 and 27 were not charged, and the right column shows the experimental results in which they were charged with 6.5 Kv15 mm. In each case, the oil flow rate was examined with the pressure in the oil reservoir chamber 29 set to atmospheric pressure and a negative pressure of 200+vsHg.

From the table, it was confirmed that the amount of carbon removed was approximately 30 times greater when charged than when not charged. This amount is sufficient for practical use.

Note that there is a correlation between the voltage of the electrode plate 25.17 and the filtration efficiency as shown in Figure 3, and IKv / 5 a
It has been found that the filtration effect is not sufficiently exerted below m. Therefore, at least I
It is desirable to apply a voltage of K v /521 or higher. Note that the O mark in FIG. 3 indicates experimental values.

Next, a second embodiment of the present invention will be described based on FIGS. 4 to 8. FIG. 4 shows a longitudinal section of an electric oil filter 35 according to the second embodiment. The oil filter 35 has a thin cylindrical case 36 with a bottom, and a filter unit 37 is housed within the case 36. The open end of the case 36 is closed with an end plate 38, and oil is introduced into the case 36 through a plurality of inlet holes 39 formed in the end plate 38. Also, an outlet is provided in the center of the end plate 38. A hole 40 is formed through which the oil from which carbon has been removed is discharged. The outer surface of the peripheral edge of the end plate 38 is supported by an annular presser plate 41, and the peripheral edge of the presser plate 41 is integrally connected to the open end of the case 36 by a hemming press.

The filter unit 37 is made by alternately laminating perforated electrode plates and filter media, and is configured to allow oil to pass from the outer circumferential side to the inner circumferential side of the filter unit 37. FIG. 5 shows a filter unit 37-2 in which the number of stacked layers of the filter unit 37 is reduced. The structure of the filter unit 37 will be explained with reference to FIG. 5. End plates 44 and 45 are provided at both ends of the filter unit 37-2, and -
A boss portion 47 having a female screw portion 46 is formed in the center of one end plate 44 . The boss portion 47 is a male threaded portion 42 formed on the outer periphery of the outlet hole 40 of the end plate 38 as shown in FIG.
are screwed together. The other end plate 5 is made of an insulating material,
A hole 48 is formed in its center.

Between the end plates 44 and 45, positive electrode plates 50a to 50c, negative electrode plates 51a to 51c, and filter media 52 and 53 are alternately stacked, and an oil passage is defined in the filter unit 37, and the filter media 52 Two types of spacers 54 and 55 are used to prevent the filter media 52 and 53 from being compressed.
It is located on the same layer as . Positive electrode plates 50a to 50c
is connected to a parent electrode 56 arranged inside the end plate 45, and this parent electrode 56 is connected to the spring 5 inserted through the hole 48 of the end plate 45.
A DC high voltage generator 59 is connected to the positive electrode via a lead wire 58 inserted through the insulating bushing 65 and the insulating bushing 65 . On the other hand, the negative electrode plates 51a to 51c are connected to the end plate 44,
This end plate 44 is connected to the negative electrode of a DC high voltage generator 59 by a lead wire 60 via the end plate 38 and the case 36 .

This DC high voltage generator 59 is designed to boost the voltage of the battery 43 to several kilovolts. Note that the electrode plate 51a~
A separation membrane 61 is pasted on the side surface of 51c (the side surface facing the positive electrode plates 50a to 50c). This separation membrane 6
1 is made of a Teflon film or the like similar to that used in the first embodiment.

The spacers 54, 55 are made of insulating rubber and have the shape shown in FIGS. 6 and 7. That is, one spacer 54 has a ring shape and is fitted around the outer periphery of a disc-shaped filter medium 52 with a hole 52a in the center. The other spacer 55 has a shape in which three arm portions 55b extend outward from an annular portion 55a, and three arm portions 55b form a fan shape between the arm portions 55b.
Two filter media 53 are arranged. Three through-holes 62.63 are formed in each of the spacers 54.55, and bolts 49 for tightening the end plates 44 and 55 together are inserted through the through-holes 62.63, as shown in FIG. . A blind plate 65 is arranged inside the parent electrode 56, and one end of the center hole 64 of the filter unit 37 is closed by this blind plate 65.

In the oil filter 35 described above, the oil introduced into the case 36 from the inlet hole 39 in FIG. 4 permeates the outer periphery of the filter unit 37 from the side surface of the filter medium 53. Carbon particles in the oil that has permeated the filter medium 53 are connected to the electrodes 51a to 51c.
The electrodes 50a to 5 are negatively charged and most of them are positive.
It is attracted to 0c. In addition, the remaining carbon particles are removed by the separation membrane 6.
1 and is separated and filtered. The oil from which most of the carbon particles have been removed is transferred to the negative electrode plates 51a to 51c and the positive electrode plate 50.
It permeates both sides of the filter medium 52 through the small holes a to 50c. After being further filtered by the filter medium 52, it exits from the inner peripheral surface to the center hole 64 and is discharged to the outside from the outlet hole 40.

In this way, in the oil filter 35, the electrodes 50a to
Since the filter media 52 and 53 are arranged on both sides of 50c and 51a to 51c, the filtration efficiency is further increased.In particular, since the carbon concentrated layer is held by the filter media 52 and 53, a large amount of concentrated layer can be stably stored. This makes it possible to extend the life of the oil filter 35.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways.
For example, the separation membrane may be composed of a nitrocellulose membrane or the like instead of a Teflon membrane, or these membranes may be bent into a chrysanthemum shape.

(Effects of the Invention) As described above, the present invention collects carbon particles in oil using electrostatic force generated by high DC voltage, and also separates and collects them using a separation membrane, which greatly improves the filtration efficiency of carbon particles. improve.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of an electric oil filter according to a first embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a filtration efficiency experimental device,
Fig. 3 is a graph of the relationship between interelectrode voltage and filtration efficiency, Fig. 4 is a vertical cross-sectional view of an electric oil filter according to the second embodiment of the present invention, and Fig. 5 is the basic structure of the filter unit of the same oil filter. 6 and 7 are plan views of the spacer, and FIG. 8 is a longitudinal sectional view taken along the line ■-■ in FIG. 5. 3... Outer cylinder electrode 4... Inner cylinder electrode 8, 26, 61... Separation membrane 19, 59... DC high voltage generator 51a-51c... Negative electrode Plate 52, 53... Filter media patent applicant Tokyo Roki Co., Ltd. Agent
Patent Attorney - Kensuke Iro Patent Attorney Masatoshi Matsumoto Filtration Efficiency (%) T

Claims (1)

[Claims] A positive electrode and a negative electrode to which a high DC voltage is applied are placed facing each other on both sides of a separation membrane having a pore size that allows carbon particles to be separated.
An electric oil filter configured to allow oil to permeate from the positive electrode side to the negative electrode side of the separation membrane.