JP2009119393A - Filter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter device which can maintain a hydraulic oil filtration performance for a long time. <P>SOLUTION: When a filter 40 in a preceding step is clogged, a safety valve 50 is actuated so that the hydraulic oil can be filtered out by the filter 40 in the succeeding step. Even when the safety valve 50 is actuated by the clogging of the filter 40 in the preceding step, since the hydraulic oil can be filtered out by the filter 40 in the succeeding step, the hydraulic oil filtration performance can be maintained for a long time as compared with a conventional filter device. When the safety valve 50 is actuated, valves 53a-53c are sucked and held by magnets 58a-58c. Since the pressure loss of the hydraulic oil in the safety valve 50 can be reduced, energy can be saved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a filter device that collects particles in a fluid.

  For example, in a hydraulic circuit of a construction machine or the like, a filter is provided in the hydraulic circuit in order to collect contaminants in the hydraulic oil flowing through the hydraulic circuit. In order to prevent the pressure in the hydraulic circuit from increasing due to clogging of the filter, a safety valve is provided. When the pressure on the upstream side of the filter exceeds a predetermined pressure, the safety valve is actuated to guide the hydraulic oil on the upstream side of the filter to the downstream side of the filter (see Patent Document 1).

JP 2000-262814 A

  However, when the safety valve is activated, the hydraulic oil is not filtered by the filter, and contaminants to be collected by the filter also flow downstream together with the hydraulic oil.

(1) The filter device according to the invention of claim 1 has a first and second filters provided in a housing attached to a counterpart device, and a pressure loss when the fluid is filtered by the first filter is a predetermined value. If the pressure is less than the value, the fluid is filtered by the first filter, and when the pressure loss when the fluid is filtered by the first filter exceeds a predetermined value, the fluid flows so that the fluid is filtered by the second filter. And switching means for switching between.
(2) The invention of claim 2 is characterized in that, in the filter device of claim 1, the first and second filters are detachable from each other.
(3) The invention according to claim 3 is the filter device according to claim 1 or claim 2, wherein the second filter is more than the first filter when the housing is attached to the counterpart device. It is attached at a position close to the side device.
(4) The invention of claim 4 detects in the filter device according to any one of claims 1 to 3 that the switching means switches the flow of the fluid so that the fluid is filtered by the second filter. And a detection electrode.
(5) The invention of claim 5 is the filter device according to claim 4, wherein the detection electrode detects that the switching means has switched the flow of the fluid so that the fluid is filtered by the second filter. And a predicting means for predicting a period until the second filter is clogged.

  According to the present invention, the filtration performance of hydraulic oil can be maintained for a long time.

--- First embodiment ---
A first embodiment of a filter device according to the present invention will be described with reference to FIGS. FIG. 1A is a diagram showing an outline of a hydraulic circuit when a conventional filter device is connected in series, and FIG. 1B is a diagram showing an outline of the hydraulic circuit of the filter device 1 according to the present invention. . FIG. 2 is a view showing the appearance of the filter device 1 according to the present invention, and FIG. 3 is a cross-sectional view of the filter device 1 attached to a counterpart device (a counterpart device) 60. In addition, 61 is a supply port for fluid (hydraulic oil) from the counterpart device 60, and 62 is a return port for hydraulic fluid of the counterpart device 60.

  As shown in FIGS. 2 and 3, the filter device 1 according to the present invention has a cylindrical housing 10. A hydraulic oil inflow port 11 and an outflow port 12 are provided at one end of the housing 10. When the filter device is attached to the counterpart device 60, the supply port 61 and the inlet 11 of the counterpart device 60 are connected, and the return port 62 and the outlet 12 of the counterpart device 60 are connected (FIG. 3). . At least two or more cylindrical filters 40 are provided inside the housing 10. In the present embodiment, a filter device provided with three filters 40 will be described as an example. The filter 40 filters the working oil when the working oil flows from the inside to the outside of the cylinder, and removes foreign matters to be removed from the working oil such as contaminants.

  One end surface (upper surface in the drawing) 41 a inside the cylinder of the filter 40 (first filter 40 a) on the most upstream side (uppermost in the drawing) is connected to the inlet 11 of the housing 10. The other end surface (the lower surface in the drawing) 42a inside the cylinder of the first filter 40a is in contact with the upstream surface (the upper surface in the drawing) of the safety valve 50 (the first safety valve 50a).

  In the filter 40 (second filter 40b) provided below the first filter 40a, one end surface (upper surface in the drawing) 41b inside the cylinder faces the downstream surface (lower surface in the drawing) of the first safety valve 50a. The other end surface (the lower surface in the drawing) 42b inside the cylinder of the second filter 40b is in contact with the upstream surface (the upper surface in the drawing) of the safety valve 50 (the second safety valve 50b).

  In the filter 40 (third filter 40c) provided below the second filter 40b, one end surface (upper surface in the drawing) 41c inside the cylinder faces the downstream surface (lower surface in the drawing) of the second safety valve 50b. The other end surface (the lower surface in the drawing) 42c inside the cylinder of the third filter 40c is in contact with the upstream surface (the upper surface in the drawing) of the safety valve 50 (the third safety valve 50c). A downstream surface (lower surface in the drawing) of the third safety valve 50 c is exposed inside the housing 10.

  4A and 4B show the structure of the first safety valve 50a. Note that the structures of the second safety valve 50b and the third safety valve 50c are the same as the structure of the first safety valve 50a, and thus the detailed structure will not be described. The first safety valve 50a includes an inlet 51a, an outlet 52a, a cylindrical valve body 53a made of a ferromagnetic material, a valve seat 55a provided with a flow path 54a, a spring 56a, and a support that supports the spring 56a. A portion 57a and a magnet 58a are provided. The inflow port 51a is an opening provided on the upstream surface of the first safety valve 50a. The outflow port 52a is an opening provided on the downstream surface of the first safety valve 50a.

  The valve body 53a is provided on the inner peripheral surface of the valve seat 55a so as to be slidable in the axial direction of the cylinder, and is biased upward in the drawing by a spring 56a. The valve body 53a is in contact with a contact portion (not shown) provided on the valve seat 55a, so that the upward movement of the valve seat 55a is restricted. Absent. The valve body 53a moves upward in the figure by the urging force of the spring 56a, thereby closing the flow path 54a provided in the valve seat 55a. Further, as will be described later, the valve body 53a moves downward in the figure to open the flow path 54a.

  As described above, the flow path 54a is an opening provided in the valve seat 55a, and communicates the inlet 51a and the outlet 52a. The magnet 58a is an annular magnet having an inner and outer diameter substantially the same as the valve body 53a, and is attached to a support portion 57a directly below the valve body 53a. When the valve body 53a is moved downward in the drawing and comes into contact with the lower part of the valve body 53a, the magnet 58a attracts and holds the valve body 53a as shown in FIG. When the valve body 53a moves downward, the flow path 54a is opened, and the inflow port 51a and the outflow port 52a are communicated with each other.

  The drain path 14 is a space formed by the outer peripheral surface of each filter 4, the outer peripheral surface of the safety valve 50, and the inner peripheral surface of the housing 10. The drain path 14 is connected to the return port 62 of the counterpart device 60 via the outflow port 12. The outlet 52c of the third safety valve 50c is connected to the drain path 14.

--- About the flow of hydraulic oil ---
The hydraulic oil flows from the supply port 61 of the counterpart device 60 into the cylinder inside the first filter 40 a through the inlet 11. If the first filter 40a is not clogged, the pressure inside the cylinder of the first filter 40a is lower than a predetermined pressure, so that the pressure difference between the upstream surface and the downstream surface of the first safety valve 50a is small. Therefore, the valve body 53a keeps moving upward in the figure by the urging force of the spring 56a, and closes the flow path 54a. Therefore, the hydraulic fluid that has flowed into the cylinder of the first filter 40a is filtered by the first filter 40a and flows into the drain path 14 outside the cylinder. At this time, foreign matters such as contaminants contained in the hydraulic oil are separated from the hydraulic oil by the first filter 40a. The foreign matter separated from the hydraulic oil is collected and held by the filter 40a. The hydraulic oil that has flowed into the drain path 14 flows out to the return port 62 of the counterpart device 60 via the outlet 12.

  When the first filter 40a is clogged by foreign matter separated from the hydraulic oil, the pressure loss when the hydraulic oil passes through the first filter 40a increases, so the pressure inside the cylinder of the first filter 40a increases. In addition, the pressure difference between the upstream surface and the downstream surface of the first safety valve 50a increases. When the pressure loss in the first filter 40a increases due to the progress of clogging, and the pressure inside the cylinder of the first filter 40a becomes higher than a predetermined pressure, the valve body 53a has an upstream surface and a downstream surface of the first safety valve 50a. Due to the pressure difference, the spring 56a moves against the urging force of the spring 56a to open the flow path 54a. That is, the first safety valve 50a operates. The valve body 53a is attracted and held by the magnet 58a. When the valve body 53a is attracted and held by the magnet 58a, the flow path 54a is opened regardless of the biasing force of the spring 56a and the pressure difference between the upstream surface and the downstream surface of the first safety valve 50a. Accordingly, there is no need to move the valve body 53a downward against the urging force of the spring 56a, and the pressure loss of the hydraulic oil when passing through the first safety valve 50a is reduced.

  When the first safety valve 50a is activated, the hydraulic oil that has flowed into the cylinder inside the first filter 40a enters the cylinder inside the second filter 40b via the inlet 51a, the flow path 54a, and the outlet 52a of the first safety valve 50a. Inflow. That is, the first safety valve 50a is a switching means for switching the flow of hydraulic oil so that the hydraulic oil is filtered by the second filter 40b when the pressure loss when the hydraulic oil is filtered by the first filter 40a exceeds a predetermined pressure. is there. If the second filter 40b is not clogged, the pressure inside the cylinder of the second filter 40b is lower than a predetermined pressure, so that the pressure difference between the upstream surface and the downstream surface of the second safety valve 50b is small. Therefore, the valve body 53b keeps moving upward in the figure by the urging force of the spring 56b, and closes the flow path 54b. Therefore, the hydraulic oil that has flowed into the cylinder of the second filter 40b is filtered by the second filter 40b and flows into the drain path 14 outside the cylinder. The hydraulic oil that has flowed into the drain path 14 flows out to the return port 62 of the counterpart device 60 via the outlet 12.

  As in the case of the first filter 40a, when the clogging of the second filter 40b proceeds and the pressure inside the cylinder of the second filter 40b becomes higher than a predetermined pressure, 2 Safety valve 50b operates.

  When the second safety valve 50b is activated, the hydraulic oil that has flowed into the cylinder inside the second filter 40b enters the cylinder inside the third filter 40c via the inlet 51b, the flow path 54b, and the outlet 52b of the second safety valve 50b. Inflow. If the third filter 40c is not clogged, the pressure inside the cylinder of the third filter 40c is lower than a predetermined pressure, so that the pressure difference between the upstream surface and the downstream surface of the third safety valve 50c is small. Therefore, the valve body 53c keeps moving upward in the figure by the urging force of the spring 56c, and closes the flow path 54c. Therefore, the hydraulic oil that has flowed into the cylinder of the third filter 40c is filtered by the third filter 40c and flows into the drain path 14 outside the cylinder. The hydraulic oil that has flowed into the drain path 14 flows out to the return port 62 of the counterpart device 60 via the outlet 12.

  As in the case of the first filter 40a and the second filter 40b, when the clogging of the third filter 40c proceeds and the pressure inside the cylinder of the third filter 40c becomes higher than a predetermined pressure, the third safety valve 50c is activated. To do.

  When the third safety valve 50c is activated, the hydraulic oil that has flowed into the cylinder of the third filter 40c flows into the drain path 14 via the inlet 51c, the flow path 54c, and the outlet 52c of the third safety valve 50c. The hydraulic oil that has flowed into the drain path 14 flows out to the return port 62 of the counterpart device 60 via the outlet 12.

  As described above, in the filter device 1 according to the first embodiment, the hydraulic oil is filtered by the first filter 40a, and when the first filter 40a is clogged, the first safety valve 50a is operated, and the second pressure loss is reduced. The hydraulic oil can be filtered by the filter 40b. Further, when the second filter 40b is clogged, the second safety valve 50b is operated, and the hydraulic oil can be filtered by the third filter 40c with a small pressure loss.

The filter device 1 of the present embodiment has the following operational effects.
(1) When the filter 40 is clogged, the safety valve 50 is activated, and the hydraulic oil can be filtered by the filter 40 in the next stage. As a result, even if the front-stage filter 40 is clogged and the safety valve 50 is activated, the hydraulic oil can be filtered by the rear-stage filter 40, so that the hydraulic oil filtration performance can be maintained for a long period of time compared to the conventional filter device. . Moreover, since the replacement frequency of the filter 40 can be reduced, the time and cost required for maintenance can be reduced.

(2) When conventional filter devices as shown in FIG. 1 (a) are arranged in series, after the front filter is clogged, hydraulic oil is supplied to the rear filter via the front safety valve. At this time, since it is necessary to operate the safety valve at the front stage, the supply pressure of the hydraulic oil becomes higher than the pressure necessary for filtering with the filter at the rear stage. On the other hand, in the filter apparatus 1 of this Embodiment, when the safety valve 50 act | operates, it comprised so that the valve bodies 53a-53c might be adsorb | sucked and hold | maintained at the magnets 58a-58c. Thereby, since the pressure loss of the hydraulic oil in the safety valve 50 can be reduced, useless energy consumption can be reduced. Further, even if the filter device 1 is multistaged, the pressure loss in the filter device 1 does not increase significantly, so that the filter device 1 can be multistaged easily.

--- Second embodiment ---
A second embodiment of the filter device according to the present invention will be described with reference to FIGS. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first embodiment. This embodiment is different from the first embodiment in that one filter unit 2 is mainly constituted by one filter 40 and one safety valve 50.

  FIG. 5 is a diagram showing the structure of the filter unit 2 of the present embodiment. In the filter unit 2, the filter 40 and the safety valve 50 of the first embodiment are provided in one housing 20. A hydraulic oil inflow port 21 and an outflow port 22 are provided at one end (upper surface in the drawing) of the housing 20. A drain inflow port 23 and an outflow port 52 are provided at the other end (the lower surface in the drawing) of the housing 20.

  One end surface (upper surface in the drawing) 41 inside the cylinder of the filter 40 is connected to the inlet 21 of the housing 20. The other end surface (lower surface in the drawing) 42 inside the cylinder of the filter 40 is in contact with the upstream surface (upper surface in the drawing) of the safety valve 50. The safety valve 50 includes an inlet 51, an outlet 52, a cylindrical valve body 53 made of a ferromagnetic material, a valve seat 55 provided with a flow path 54, a spring 56, and a support portion 57 that supports the spring 56. And a magnet 58. The components 51 to 58 of the safety valve 50 correspond to the components 51a to 58a of the first safety valve 50a of the first embodiment, respectively.

  As shown in FIG. 6, the two filter units 2 can be connected to the illustrated lower surface of one filter unit 2 and the illustrated upper surface of the other filter unit 2. When the filter units 2 are connected to each other, the outlet 52 of the upper filter unit 2 in the figure and the inlet 21 of the lower filter unit 2 are connected, and the drain inlet 23 of the upper filter unit 2 is shown in the lower part of the figure. The outlet 22 of the filter unit 2 is connected. On the lower surface of the lowermost filter unit 2 shown in the figure, an outlet 52 and a drain inlet 23 of the lowermost filter unit 2 shown in the figure are connected, and a lid is provided so that hydraulic oil does not leak outside the filter unit 2. 25 is attached.

  When the filter unit 2 is attached to the counterpart device 60, the inlet 21 of the filter unit 2 closest to the counterpart device 60 (not shown) at the uppermost stage in FIG. 6 is connected to the supply port 61 of the counterpart device 60. The outflow port 22 is connected to the return port 62 of the counterpart device 60 (not shown). In FIG. 6, the number of stages of the filter unit 2 is three, but the number of stages of the filter unit 2 attached to the counterpart device 60 may be one, two, or four or more. It may be. Note that the flow of hydraulic oil is the same as that in the first embodiment, and a description thereof will be omitted.

The filter device according to the second embodiment has the following operational effects in addition to the operational effects of the first embodiment.
(1) Since one filter unit 2 is constituted by one filter 40 and one safety valve 50, only the filter unit 2 provided with the clogged filter 40 can be replaced. The cost can be reduced.

(2) Since the filter units 2 can be connected to each other, the number of stages of the filter unit 2 attached to the counterpart device 60 is arbitrarily adjusted according to the installation space for the counterpart device 60, the replacement frequency of the filter unit 2, and the like. Can be flexible.

--- Third embodiment ---
A third embodiment of the filter device according to the present invention will be described with reference to FIGS. In the following description, the same components as those in the first and second embodiments are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first and second embodiments. This embodiment is different from the first and second embodiments mainly in that the hydraulic oil is first filtered by the filter 40 farthest from the counterpart device 60.

  FIG. 7 is a diagram showing the structure of the filter unit 3 of the present embodiment. The filter unit 3 has a structure in which a cylindrical housing 30 is provided on the outer side of the housing 20 of the filter unit 2 of the second embodiment. The space between the outer peripheral surface of the housing 20 and the inner peripheral surface of the housing 30 forms a bypass passage 31 for hydraulic oil. The lower end of the bypass passage 31 shown in FIG. 7 is called a bypass passage inlet 32, and the upper end of the bypass passage 31 shown in FIG. 7 is called a bypass passage outlet 33. As will be described later, the flow of the hydraulic oil in the drain passage 14 flows from the upper side to the lower side in the figure, contrary to the second embodiment, so that the outlet 22 is at the other end (the lower surface in the figure) of the housing 20. The drain inlet 23 is provided at one end (upper surface in the drawing) of the housing 20.

  As shown in FIG. 8, the two filter units 3 can be connected to the illustrated lower surface of one filter unit 3 and the illustrated upper surface of the other filter unit 3. When the filter units 3 are connected to each other, the outlet 52 of the upper filter unit 3 in the figure is connected to the inlet 21 of the lower filter unit 3 in the figure, and the outlet 22 of the upper filter unit 3 in the figure is connected to the lower outlet in the figure. A drain inlet 23 of the filter unit 3 is connected. Furthermore, a bypass flow path inlet 32 of the upper filter unit 3 in the figure is connected to a bypass flow path outlet 33 of the lower filter unit 3 in the figure.

  On the upper surface of the uppermost filter unit 3 shown in the figure, the drain inlet 23 of the uppermost filter unit 3 shown in the figure is closed, the inlet 21 and the bypass passage outlet 33 are connected, and the working oil is filtered. A lid 35 is attached so as not to leak outside the unit 3.

  The filter unit 3 is attached to the counterpart device 60 on the lower surface in the drawing of the filter unit 3 (FIG. 8). When the filter unit 3 is attached to the counterpart device 60, the bypass channel inlet 32 of the filter unit 3 closest to the counterpart device 60 at the lowest level in FIG. 8 is connected to the supply port 61 of the counterpart device 60. The outflow port 22 and the outflow port 52 are connected to the return port 62 of the counterpart device 60. In FIG. 8, the number of stages of the filter unit 3 is three, but the number of stages of the filter unit 3 attached to the counterpart device 60 may be one, two, or four or more. It may be.

--- About the flow of hydraulic oil ---
The hydraulic oil enters the bypass passage inlet 32 of the lowermost filter unit 3 shown in the drawing from the supply port 61 of the counterpart device 60, flows from the lower side to the upper side of the bypass passage 31, and passes through the uppermost filter shown in the drawing. It flows from the inlet 21 of the unit 3 into the cylinder inside the uppermost filter 40 in the figure. The hydraulic oil that has flowed into the cylinder of the uppermost filter 40 in the figure is filtered by the uppermost filter 40 in the figure, flows into the drain path 14, flows downward in the drain path 14, and flows through the drain path 14. From the outlet 22 to the return port 62 of the counterpart device 60.

  When the illustrated uppermost filter 40 is clogged, the illustrated uppermost safety valve 50 operates to guide the hydraulic oil to the inside of the cylinder of the illustrated middle filter 40, as in the first and second embodiments. . The hydraulic fluid guided to the inside of the cylinder of the middle filter 40 shown in the figure is filtered by the middle filter 40 and flows into the drain path 14, flows downward in the figure 14, and flows through the drain path 14. It flows from the outlet 22 to the return port 62 of the counterpart device 60.

  When the middle filter 40 shown in the figure is clogged, the middle safety valve 50 shown in FIG. The hydraulic oil guided to the inside of the cylinder of the lowermost filter 40 shown in the figure is filtered by the lowermost filter 40 shown in the figure, flows into the drain path 14, and flows from the outlet 22 to the return port 62 of the counterpart device 60.

  When the lowermost filter 40 shown in the figure is clogged, the lowermost safety valve 50 shown in the figure is actuated to guide the hydraulic oil to the return port 62 of the counterpart device 60 via the outlet 52.

According to the filter device of the third embodiment described above, the following operational effects are obtained in addition to the operational effects of the first and second embodiments.
(1) The filter units 3 are configured to be connectable to each other, attached to the counterpart device 60 with the lowermost filter unit 3 shown in FIG. The filter 40 is guided to the farthest filter 40 (the uppermost stage in the figure). Therefore, the filter 40 is configured so as to be clogged in order from the upper filter 40 in the drawing. Moreover, it will be comprised so that it can remove in order from the filter unit 3 of upper illustration. As a result, only the filter unit 3 that has been clogged can be replaced without removing the filter unit 3 that has not been clogged, which facilitates the replacement operation.

--- Fourth embodiment ---
A fourth embodiment of the filter device according to the present invention will be described with reference to FIGS. In the following description, the same components as those in the first to third embodiments are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first to third embodiments. This embodiment is different from the first to third embodiments in that it is configured to detect that the safety valve 50 is operated.

  FIG. 9 is a view of the filter unit 2 according to the fourth embodiment when the support portion 57 immediately below the valve body 53 of the safety valve 50 is viewed from the valve body 53 side. The structure of the filter unit 2 of the fourth embodiment is the same as that of the filter unit 2 of the second embodiment, except for the part relating to the detection of the operation of the safety valve 50 described below. The support portion 57 is provided with electrodes 71 and 72 that are electrically insulated from each other. When the safety valve 50 is activated and the valve body 53 is attracted and held by the magnet 58, the lower end of the valve body 53 comes into contact with the electrodes 71 and 72, and the electrode 71 and the electrode 72 are electrically connected. . That is, the valve body 53 and the electrodes 71 and 72 constitute a switch, and when the valve body 53 is attracted and held by the magnet 58, the electrode 71 and 72 are closed. The electrodes 71 and 72 are detection electrodes that detect that the safety valve 50 is activated.

  As shown in FIG. 10, a detection device 81 for detecting a change in resistance between the electrodes 71 and 72 is connected to the electrodes 71 and 72, respectively. The detection device 81 detects a change in resistance between the electrodes 71 and 72 of each filter unit 2. A control device 82 is connected to a display monitor (not shown). The control device 82 obtains information on a change in resistance between the electrodes 71 and 72 of each filter unit 2 detected by the detection device 81. Based on the obtained information, the control device 82 provides information on which filter unit 2 filter 40 is clogged, and which filter unit 2 filter 40 is clogged and when. Information is presented to the operator of the counterpart device 60 via a display monitor (not shown). The control device 82 is a prediction unit that predicts a period until the filter 40 of the filter unit 2 is clogged.

  For example, the control device 82 measures the time until the safety valve 50 of the uppermost filter unit 2 shown in the figure operates, acquires information on the operation time of the counterpart device 60 within a certain period, When the filter 40 of the lower filter unit 2 is clogged is calculated and displayed on a display monitor (not shown). For example, by raising specific numbers, for example, the filtration time of hydraulic oil required until the safety valve 50 of the uppermost filter unit 2 in the figure is activated is 750 hours, and the counterpart device 60 is operated for one month. When obtaining the information that the time is 250 hours, the control device 82 predicts that the filter 40 of the filter unit 2 in the middle stage and the lowest stage in the figure is clogged after about 3 months and about 6 months, The prediction result is displayed on a display monitor (not shown).

  Further, for example, the control device 82 has the date and time when the filter 40 of the uppermost filter unit 2 shown in the figure is clogged (the safety valve 50 has been activated), or the date and time when the filter 40 of the uppermost filter unit 2 shown in the previous figure is replaced Etc. and display them on the display monitor. Further, for example, when it is determined that the filter 40 of any one of the filter units 2 is close to the time when the filter 40 is clogged, the control device 82 displays a display for prompting the preparation of the spare filter unit 2 (not shown). Display on the display monitor.

  The control device 82 may be disposed near the detection device 81 or may be disposed in a remote place away from the detection device 81. Further, the detection device 81 and the control device 82 may be connected by wire or may be connected wirelessly.

According to the filter device of the fourth embodiment described above, in addition to the functions and effects of the first to third embodiments, the following functions and effects are achieved.
(1) The presence or absence of the operation of the safety valve 50 is detected by the detection device 81 as a change in resistance between the electrodes 71 and 72, and information is transmitted to the control device 82. Thereby, it can be grasped | ascertained from which the filter unit 2 connected has raised clogging.
(2) The filter 40 is configured to predict and present a period (time) until the filter 40 is clogged. Accordingly, the user of the counterpart device 60 determines the degree of contamination of the hydraulic oil by comparing, for example, the time until the filter 40 is clogged with the actual operation time of the counterpart device 60. be able to.

  In the above description, the fluid from the counterpart device 60 has been described as the hydraulic oil, but other types of fluid such as engine oil (lubricating oil) or an aqueous solution may be used. Moreover, you may combine each embodiment and modification which were mentioned above, respectively.

  In addition, this invention is not limited to the thing of embodiment mentioned above at all, The fluid was supplied to the 1st and 2nd filter provided in the housing attached to the apparatus of the other party, and the 1st filter. If the pressure loss in the first filter is less than or equal to a predetermined value, the fluid is supplied to the first filter, and the pressure loss in the first filter when the fluid is supplied to the first filter is a predetermined value. If it exceeds, the filter device of various structures provided with the switching means which switches the flow of a fluid so that a fluid may be supplied to a 2nd filter is included.

(A) is a figure which shows the outline of the hydraulic circuit at the time of connecting a conventional filter apparatus in series, (b) is a figure which shows the outline of the hydraulic circuit of the filter apparatus 1 by this invention. 1 is an external view of a filter device 1. FIG. It is sectional drawing of the filter apparatus 1 attached to the other party's apparatus (counterpart apparatus) 60. It is a figure which shows the structure of the 1st safety valve 50a. It is a figure which shows the structure of the filter unit 2 of 2nd Embodiment. It is sectional drawing at the time of connecting filter units 2 mutually. It is a figure which shows the structure of the filter unit 2 of 3rd Embodiment. It is sectional drawing of the filter apparatus attached to the other party's apparatus (other party apparatus) 60. FIG. It is a figure when the support part 57 just under the valve body 53 of the safety valve 50 is seen from the valve body 53 side about the filter unit 2 of 4th Embodiment. It is sectional drawing at the time of connecting filter units 2 mutually.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter apparatus 2,3 Filter unit 10,20,30 Housing 40 Filter 50 Safety valve 53 Valve body 54 Flow path 58 Magnet 71, 72 Electrode 81 Detection apparatus 82 Control apparatus

Claims (5)

First and second filters provided in a housing attached to a counterpart device;
If the pressure loss when the fluid is filtered with the first filter is below a predetermined value, the fluid is filtered with the first filter, and the pressure loss when the fluid is filtered with the first filter is a predetermined value. And a switching unit that switches a flow of the fluid so that the fluid is filtered by the second filter when the value is exceeded. The filter device according to claim 1,
The filter device, wherein the first and second filters are detachable from each other. The filter device according to claim 1 or 2,
The filter device, wherein the second filter is attached to a position closer to the counterpart device than the first filter when the housing is attached to the counterpart device. In the filter apparatus as described in any one of Claims 1-3,
The filter device further comprising a detection electrode that detects that the switching unit switches the flow of the fluid so that the fluid is filtered by the second filter. The filter device according to claim 4, wherein
A period until the second filter is clogged based on a period until the detection electrode detects that the switching means switches the flow of the fluid so as to filter the fluid with the second filter. A filter device further comprising prediction means for predicting.

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