JP2010022940A - Filter washing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter washing apparatus with which a filter can be back-washed with filtered fluid having passed through the filter, and which does not require extra facilities, such as a filter body and a duct for washing. <P>SOLUTION: The filter 24 for filtering fuel is disposed on a pump suction side pipe 23 which connects a fuel tank 21 for storing fuel as the fluid with a pump 22 for sucking the fuel in the fuel tank 21 and force-feeding the fuel toward an object of supply, and a storage chamber 29 for storing a specified amount of the filtered fluid is connected to a pipe 23a of the pump suction side pipe 23 closer to the down stream side than the filter 24 by branch connection. In the storage chamber 29, a piston 30 and a recovery spring 31 are disposed to configure a fuel force-feeding means 32, and the filtered fuel is force-fed into the filter 24 by the fuel force-feeding means 32 so as to wash the filter body 26. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a filter cleaning device that cleans and regenerates a filter by a so-called backwashing action in which a fluid flows back to the filter.

  The background art will be described using a filter cleaning device used in a fuel circuit of a diesel engine in a construction machine as an example.

  As shown in FIG. 5, the fuel circuit includes a fuel tank (fluid tank) 1 that stores fuel, a pump 2 that pumps the fuel in the fuel tank 1 toward an engine that is a fluid supply target, and the fuel circuit. The pump suction side pipe line 3 connecting the tank 1 and the pump 2 and a filter 4 provided in the pump suction side pipe line 3 are filtered by the filter 4 and supplied to the engine.

  The filter 4 is configured such that a filter body 6 is provided in a filter case 5, and the fuel sucked from the suction port 7 is filtered by the filter body 6 and discharged from the discharge port 8.

  In this circuit, the filter main body 6 is replaced when the clogging is caused by the filtering action or is periodically replaced. May be lengthened temporarily.

  Here, as a technique for cleaning the filter body 6 without removing it from the filter case 5, those disclosed in Patent Documents 1 and 2 are known. These all relate to the watering device, but can be diverted to the fuel circuit.

  In this case, according to the first known technique shown in Patent Document 1, as shown in FIG. 6, the first between the filter 4 and the pump 2 (filter downstream side pipe) 3a in the pump suction side pipe 3 is first. A second switching valve 11 is provided in each of the switching valve 9 and the pump discharge side pipe line 10.

  On the other hand, a cleaning port 12 is provided in the filter case 5 along with the discharge port 8, and a cleaning line 13 is provided between the cleaning port 12 and the outlet side of the second switching valve 11. Reference numeral 14 denotes a drain cock provided in the filter case 5.

  In this configuration, during normal operation, both switching valves 9 and 11 are set to the illustrated operating positions A, and the fuel is shown in the solid line arrow as shown by the solid tank arrow, the fuel tank 1, the filter 4, the first switching valve 9, the pump 2, The engine is supplied to the engine through the route of the second switching valve 11.

  On the other hand, at the time of filter cleaning, both switching valves 9 and 11 are respectively switched to the cleaning position b. In this state, fuel is sent in the reverse direction from the cleaning port 12 to the filter 4 through the fuel tank 1, the first switching valve 9, the pump 2, the second switching valve 11, and the cleaning pipeline 13 as indicated by the broken line arrows. .

  By this back washing action, the dust adhering to the filter body 6 is separated and removed, and is discharged out of the filter by the operation of the drain cock 14.

In the second known technique, a filter body for cleaning is provided in the filter case in addition to the original filter body for operation, and after the fuel in the tank is filtered by the filter body for cleaning, the switching valve It is configured to be sent back to the filter main body during operation via.
JP 2003-253614 A JP 2003-239218 A

  However, according to the first known technique, the unfiltered fuel is sent back to the filter 4 via the pump 2 when the filter is washed, so that dust in the fuel enters the pump 2 and the switching valves 9 and 10. Bad effects occur.

  In addition, any known technique requires an extra conduit called the cleaning conduit 13, which complicates the circuit configuration and increases the equipment cost.

  In particular, according to the second known technique, a filter main body for cleaning must be added in addition to the cleaning pipe 13, so that the circuit configuration becomes complicated and the equipment cost increases, and it is disadvantageous in terms of maintenance. It becomes.

  Such a problem is not limited to the fuel circuit, but is present in all fluid circuits including a filter, and a countermeasure has been desired.

  Therefore, the present invention can be back-washed by the filtered fluid that has passed through the filter, and does not require extra equipment such as a filter main body or a pipe for cleaning, can simplify the circuit configuration and reduce the cost, and is advantageous for maintenance. A simple filter cleaning apparatus is provided.

  According to the first aspect of the present invention, a filter for filtering the fluid is provided in a pump suction side pipe line that connects a fluid tank that stores the fluid and a pump that sucks the fluid in the fluid tank and pumps the fluid toward the supply target. In addition, a storage chamber for storing a certain amount of filtered fluid is branched and connected to a pipe downstream of the filter in the pump suction side pipe, and the fluid in the storage chamber is pushed into the filter for filter cleaning. Fluid pushing means is provided.

  According to a second aspect of the present invention, in the configuration of the first aspect, a fluid pushing means is configured by providing a piston for pushing out a fluid and a return spring for returning the piston to its original position in the storage chamber.

  According to a third aspect of the present invention, in the configuration of the second aspect, an operation knob for manually sliding the stone is provided.

  According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the pipe is opened and closed between the branch connection point of the storage chamber in the filter downstream side pipe in the pump suction side pipe and the pump. A switching valve is provided.

  According to a fifth aspect of the present invention, in the configuration according to any one of the first to fourth aspects, a switching valve for opening and closing the pipe is provided in a pipe upstream of the filter in the pump suction side pipe. .

  According to the present invention, at the time of filter washing (back washing), the unfiltered fluid taken out from the tank is not sent back to the filter via the pump as in the first known technique, but is passed through the filter to the storage chamber. Since the stored filtered fluid is washed back by the fluid pushing means to the filter, there is no possibility that dust in the fluid enters the pump or the like.

  Further, since the filtered fluid is caused to flow back to the filter via the pump suction side pipe, no extra filter body or pipe only for cleaning is required. Therefore, the equipment cost is low, the circuit configuration is simple, and the maintenance is advantageous.

  According to the second and third aspects of the invention, since the fluid pushing means is constituted by the piston for pushing out the fluid in the storage chamber and the return spring for returning the piston to the original position, the structure of the fluid pushing means is simple and inexpensively manufactured. can do.

  In particular, according to the invention of claim 3, since the piston is manually slid by the operation knob, the equipment cost can be further reduced.

  According to the invention of claim 4, since the switching valve is provided between the branch connection point of the storage chamber and the pump in the filter downstream side pipe in the pump suction side pipe, the fluid pushing pressure at the time of cleaning the filter acts on the pump. Thus, adverse effects such as damaging the seal can be avoided.

  On the other hand, according to the invention of claim 5, since the switching valve is provided in the upstream side pipe line in the pump suction side line, the switching valve can prevent the dust separated by the filter cleaning from returning to the tank. .

  An embodiment of the present invention will be described with reference to FIGS.

  In the embodiment, a case where the present invention is applied to a filter cleaning device used in a fuel circuit of a diesel engine in a construction machine is taken as an example in accordance with the description of the background art.

1st Embodiment (refer FIGS. 1-3)
In the fuel circuit shown in FIGS.
(A) A fuel tank 21 for storing fuel, a pump 22 for sucking the fuel in the fuel tank 21 and pumping it toward the engine, a pump suction side pipe line 23 connecting the fuel tank 21 and the pump 22, and A filter 24 provided in the pump suction side pipe line 23, and in operation, fuel in the tank is filtered by the filter 24 and supplied to the engine,
(B) The filter 24 includes a filter main body 26 provided in a filter case 25, and is configured such that fuel sucked from the suction port 27 is filtered by the filter main body 26 and discharged from the discharge port 28. This is the same as the first known technique shown in FIG.

  As a difference, in this filter cleaning apparatus, a cylinder for storing a certain amount of filtered fuel in a pipe line 23a downstream of the filter 24 (between the filter 24 and the pump 22) in the pump suction side pipe line 23. The storage chamber 29 is branched and connected.

  In the storage chamber 29, there are provided a piston 30 that is slid upwardly by the operation knob 30a in FIGS. 1 and 2, and a return spring (compression coil spring) 31 that returns the piston 30 to its original position. A fuel (fluid) pushing means 32 is configured.

  Further, a switching valve 33 for opening and closing the pipe line 23 is provided between the branch connection point of the storage chamber 29 in the filter downstream side pipe line 23 a in the pump suction side pipe line 23 and the pump 22. The switching valve 33 may be a manual type, a hydraulic pilot type or an electromagnetic pilot type.

  1 and 2, reference numeral 23 b denotes a filter upstream side pipe line in the pump suction side pipe line 23, and 34 denotes a drain cock provided in the filter case 25.

  In this configuration, at the time of filter cleaning, the piston 30 of the fuel pushing means 32 is pushed upward in the figure with the switching valve 33 closed as shown in FIG.

  As a result, the fuel (filtered) stored in the storage chamber 29 is sent back to the filter 24.

  Specifically, as shown in FIG. 3, the fuel is pushed into the filter main body 26 from the discharge port 28, passes through the filtration hole of the main body 26, and goes out of the main body.

  By this back washing action, the dust adhering to the filter body 26 is separated and removed, and the filter 24 is washed and regenerated.

  The piston pushing operation may be performed once or a plurality of times depending on the situation.

  As described above, when the filter is washed, the non-filtered fuel taken out from the tank 1 is not sent back to the filter 4 via the pump 2 as in the first known technique shown in FIG. Since the fuel is washed back by the fuel pushing means 32 from the storage chamber 29 on the downstream side of the filter to the filter 24, there is a risk that dust in the fuel may enter the pump and cause clogging. There is no.

  Further, since the filtered fuel is caused to flow back to the filter 24 via the filter downstream side pipe line 23a in the pump suction side pipe line 23, an extra filter main body and pipe line only for cleaning are not required. Therefore, the equipment cost is low, the circuit configuration is simple, and the maintenance is advantageous.

  On the other hand, since the piston 30 and the return spring 31 are provided in the storage chamber 29 to constitute the fuel pushing means 32, the structure of the pushing means 32 is simple and can be manufactured at low cost.

  Moreover, since the piston 30 is manually slid by the operation knob 30a, the equipment cost can be further reduced.

  Further, since the switching valve 33 that shuts off the filter 24 and the pump 22 is provided between the branch connection point of the storage chamber 29 and the pump 22 in the filter downstream side pipe line 23 a, the fuel pushing pressure at the time of cleaning the filter is increased by the pump 22. It is possible to avoid adverse effects such as damaging the seal by acting on it.

Second embodiment (see FIG. 4)
Only differences from the first embodiment will be described.

  In the second embodiment, a switching valve 35 similar to the switching valve 33 is also provided in the filter upstream side pipe line 23 b (between the filter 24 and the fuel tank 21) in the pump suction side pipe line 23.

  By so doing, it is possible to reliably prevent the dust separated from the filter 24 (filter body 26) from returning to the fuel tank 21 by the switching valve 35 during filter cleaning.

Other Embodiments (1) The piston 30 of the fuel push-in means 32 is not directly operated by manual operation using the operation knob 30a as in the above embodiment, but is configured to be remotely operated using a wire or a link. Good.

  Moreover, it is good also as a power drive type structure which drives piston 30 with a hydraulic motor, an electric motor, a hydraulic motor, a hydraulic cylinder etc. instead of a manual type.

  (2) If the fuel pushing pressure is within a range that does not adversely affect the pump 22, the switching valve 33 of the filter downstream side pipe line 23a is not necessarily provided.

  Further, the switching valve 35 of the filter upstream pipe 23b may be omitted when there is no possibility that dust separated by cleaning returns to the fuel tank 21.

  (3) The present invention can be applied not only to a fuel circuit for a diesel engine of a construction machine, but also to a hydraulic circuit of a hydraulic construction machine, a watering circuit of a watering device, or the like.

It is a circuit block diagram which shows 1st Embodiment of this invention. FIG. 2 is a view corresponding to FIG. 1 illustrating a state during filter cleaning. It is a partial cross section enlarged view which shows the flow of the fuel with respect to the filter at the time of filter washing | cleaning. FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment of the present invention. It is a circuit block diagram of the fuel circuit which does not have a filter washing | cleaning apparatus. It is a circuit block diagram which shows the well-known technique which provided the filter washing | cleaning apparatus.

Explanation of symbols

21 Fuel tank (fluid tank)
22 Pump 23 Pump suction side pipe 23a Filter downstream side pipe 23b in the pump suction side pipe 23b Filter upstream side pipe 24 Filter 25 Filter case 26 Filter body 29 Filter chamber 29 Piston 30a Operation knob 31 Return spring 32 Fuel push-in Means 33 Switching valve provided in filter downstream pipe 35 Switching valve provided in filter upstream pipe

Claims (5)

  A filter for filtering fluid is provided in a pump suction side pipe connecting a fluid tank that stores fluid and a pump that sucks the fluid in the fluid tank and pumps the fluid toward a supply target. A storage chamber for storing a certain amount of filtered fluid is branched and connected to a pipe line downstream of the filter in the channel, and fluid pushing means for pushing the fluid in the storage chamber into the filter for cleaning the filter is provided. A filter cleaning device.   2. The filter cleaning apparatus according to claim 1, wherein a piston for pushing out fluid and a return spring for returning the piston to its original position are provided in the storage chamber to constitute a fluid pushing means.   3. The filter cleaning device according to claim 2, further comprising an operation knob for manually sliding the piston.   The switching valve which opens and closes the said pipe line is provided between the branch connection point of the storage chamber in the filter downstream side pipe line in the pump suction side pipe line, and the pump. The filter cleaning apparatus according to claim 1.   The filter cleaning apparatus according to any one of claims 1 to 4, wherein a switching valve for opening and closing the pipe is provided in a pipe upstream of the filter in the pump suction side pipe.

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