JP3963009B2 - Diesel filter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a diesel filter provided in a fuel supply system of an automobile or the like, and more particularly to a diesel filter in which a fuel recirculation valve is disposed so as not to protrude from a case.
[0002]
[Prior art]
Diesel engines have long been used as engines for automobiles and the like.
[0003]
A diesel engine uses light oil as fuel, compresses the light oil to a high pressure with an injection pump, injects it from an injector into a combustion chamber of the engine, and self-combusts in the combustion chamber.
[0004]
The fuel system is shown in FIG. The fuel system is mainly composed of an injection pump 1 and an injector 3, and includes a common rail 2, a fuel tank 4, a diesel filter 5 and the like as others. The injection pump 1 is a pump that supplies high-pressure fuel, and the common rail 2 distributes the high-pressure fuel produced by the injection pump 1 to the injectors 3 of each cylinder. The black arrow indicates the flow of fuel from the fuel tank 4 to the injector 3, and the white arrow indicates the flow of recirculated fuel.
[0005]
Incidentally, foreign matters such as solid impurities such as dust and rust, sludge such as carbon and gum-like substances, and moisture are mixed in the fuel. This foreign matter is a cause of wear and sticking of the injector 3 and the like and needs to be removed. Therefore, the diesel filter 5 is provided.
[0006]
In this way, the diesel filter 5 removes solids such as dust contained in the fuel supplied to the engine, prevents mechanical wear and rusting of the injector 3 and the like, and improves durability and engine stability. This is to ensure operation.
[0007]
In addition, the diesel filter 5 requires two other functions. One of them is a water separation function. The fuel contains moisture. This water is divided into dissolved water and free water. Dissolved water is consumed with the fuel without stagnation in the fuel path, so there is no harmful effect. However, free water has a higher specific gravity than light oil, so it stagnates in the injection pump and easily causes rust and sticks. This free water is contained in the supplied fuel as free water, enters as rain water when refueling, moisture in the air enters as water droplets, or dissolved water precipitates due to a drop in fuel temperature, etc. appear.
[0008]
The second function is a wax removal function. Light oil has the property of precipitating wax at low temperatures. If light oil that is not suitable for the air temperature is used, a large amount of wax precipitates, the clogging element clogs, fuel stops flowing, and the engine may stop. Therefore, a function for maintaining the fluidity of the fuel is required even at a low temperature. For this reason, the diesel filter 5 is provided with a bimetal fuel recirculation valve. When the outside air falls below a predetermined level, a part of the fuel compressed by the injection pump 1 and having a high temperature is recirculated, and the element is warmed. Prevents clogging.
[0009]
FIG. 6 shows an outline of the return route of the return fuel. That is, a bimetallic fuel recirculation valve 7 is attached to the cap 6 of the diesel filter 5, and a path is formed by connecting the injection pump 1 and the fuel recirculation valve 7 via the fuel return pipe 8a. When the temperature of the fuel supplied into the diesel filter 5 falls, the bimetal valve in the fuel recirculation valve 7 opens, and a part of the warm fuel in the injection pump 1 is recirculated to the diesel filter 6 from the fuel return pipe 8a. Become. The recirculated fuel is then returned to the fuel tank 4 through the fuel return pipe 8b.
[0010]
As a diesel filter equipped with a conventional bimetal type fuel recirculation valve, a diesel filter described in Japanese Patent Laid-Open No. 61-8458 is known. This is shown in FIG. In brief, the diesel filter a is composed of a cup-shaped case b that forms an outer shell, and a cap c that is attached to the upper open end of the case b. A fuel supply pipe d and a fuel discharge pipe e are attached to the cap c, and fuel is supplied and discharged through the pipes.
[0011]
A filtering member g having a fuel passage h and an element i is accommodated in the case b, and a lower space j is formed below the filtering member g. The lower space j is a chamber having a function of separating and accumulating water contained in the fuel, and a drain cock k is provided therein.
[0012]
The fuel supplied into the case b from the fuel supply pipe d descends in the element i from the upper part of the element i, and impurities in the fuel are removed when descending in the element i, and the filtered fuel is in the lower space j. To. The fuel introduced into the lower space j is changed in direction by 180 degrees in the lower space j and is discharged upward from the fuel discharge pipe e through the central fuel passage h upward. Water is separated when changing. Since water has a higher specific gravity than fuel, the separated water collects in the lower space j. When a predetermined amount of separated water accumulates, the drain cock k is opened and the separated water is discharged. Further, a fuel recirculation valve m formed from a bimetal valve n or the like is attached to the cap c, and the recirculated fuel is introduced through the fuel return inflow pipe p.
[0013]
The fuel return valve m, the fuel return inflow pipe p, and the fuel return outflow pipe q correspond to the fuel return valve 7, the fuel return pipe 8a, and the fuel return pipe 8b shown in the fuel system diagram of FIG. When the temperature of the fuel returned from the pipe p into the valve chamber r falls below a predetermined value, the bimetal valve n is closed, and a part of the warm fuel in the injection pump 1 is returned to the diesel filter a through the fuel return inflow pipe p. The recirculated fuel flows into the element i and warms the element i. Therefore, precipitation of wax is prevented, and as a result, clogging of the element i is prevented. Further, when the temperature of the returned fuel becomes equal to or higher than a predetermined value, the bimetal valve n is opened and returned to the fuel tank 4 through the fuel return outflow pipe q.
[0014]
By the way, in addition to the fuel recirculation valve introduced above and its arrangement on the upper surface of a diesel filter in recent years, a hand pump for sending air when the fuel is empty, for detecting clogging of the filtration part Since a clogging sensor or the like is provided, there is no space on the upper surface and there is no degree of design freedom.
In addition, since the low temperature fuel supplied from the fuel tank and the warm fuel returned from the injection pump merge immediately in the space above the element or in the element, the temperature of the warm fuel is lowered and the element cannot be efficiently heated.
[0015]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a diesel filter in which a fuel recirculation valve is disposed in a space formed below a filtering member, thereby eliminating the space limitation on the upper surface of the diesel filter and efficiently heating the element. That is.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following configuration.
[0017]
In the invention which concerns on Claim 1, in the diesel filter which comprises the case which forms an outer shell, the filtration member accommodated in this case, and the lower space formed under this filtration member, the said lower part A structure in which a fuel recirculation valve is provided in a case forming a space, and the recirculated fuel from the fuel recirculation valve is recirculated into the lower space through an opening provided in the case. And by such a structure, the restriction | limiting on the space of the upper surface of a diesel filter is lose | eliminated, and precipitation of the waxing in an element is reduced more efficiently. Also, Since the agitation of the separated water accumulated in the lower space is prevented by the reflux fuel, the separation water is less discharged to the fuel discharge pipe side.
[0018]
In the invention according to claim 2, a recess is formed in a part of the case forming the lower space, a fuel recirculation valve is provided in the recess, and a recirculation fuel from the fuel recirculation valve is provided in the recess. A configuration in which the gas is refluxed from the opening into the lower space. With such a configuration, the diesel filter can be easily attached to the mounting space, and the fuel recirculation valve is not damaged during the installation.
[0020]
Claim 3 In the invention which concerns on this, the structure which made the upper part of the said opening a divergent shape. With such a configuration, the reflux fuel flows almost uniformly over the entire circumference of the element, so that the precipitation of wax within the element is more efficiently reduced.
[0021]
Claim 4 In the invention which concerns on this, The structure which varied the right-and-left inclination of the said divergent shape. With such a configuration, even if the opening for recirculating the fuel is shifted from the center of the case, the recirculated fuel can flow almost evenly over the entire circumference of the element, so that the wax deposits in the element. Is more efficiently reduced.
[0022]
Claim 5 In the invention which concerns on this, the structure which provided the check valve in the upper part of the said opening. With such a configuration, the fuel in the internal space does not flow backward to the filtered fuel side.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view of a fuel supply system of the present invention, and FIG. 2 is a cross-sectional view showing an embodiment of a diesel filter of the present invention.
[0024]
As shown in FIG. 1, the fuel in the fuel tank 4 is sent to the injection pump 1 through the diesel filter 5 as indicated by the black arrow, and is converted into high-pressure fuel by the injection pump 1. The high-pressure fuel is further distributed to the injectors 3 of the respective cylinders via the common rail 2 as indicated by black arrows, and is injected into the respective cylinders from the injectors 3. On the other hand, the surplus fuel is returned to the diesel filter 5 through the fuel return pipe 7a as shown by the white arrow and is returned to the fuel tank 4 through the fuel return pipe 7b. The structure of the diesel filter 5 will be further described in detail with reference to FIG. Reference numeral 6 denotes a cap at the top of the diesel filter 5.
[0025]
The diesel filter 10 includes a cup-shaped case 11 that forms an outer shell, and a cap 12 that is detachably attached to an upper opening end of the case 11. The cap 12 is made of resin, and a supply pipe mounting portion 12d and a discharge pipe mounting portion 12e are formed above the cap 12 in the diametrical direction. The fuel supply pipe 13 is integrally connected to the supply pipe attachment portion 12d with the packing 13a attached thereto, and the fuel discharge pipe 14 is integrally connected to the discharge pipe attachment portion 12e with the packing 14a attached. The
[0026]
In addition, when the fuel supply pipe 13 is attached to the supply pipe attachment portion 12d, the first check valve 12f is sandwiched, and the second check valve 12g is attached above the inlet 12b. The first check valve 12f and the second check valve 12g have the same function, and allow the flow from the fuel supply pipe 13 side to the filtration member 16 side, but prevent the reverse flow. Therefore, it is provided for smoothly operating the hand pump 15.
[0027]
A hand pump 15 is attached above the cap 12. The hand pump 15 includes a hollow pump case 15a that forms an outer shell and a lid portion 15d. A plunger 15b that is biased upward by a spring 15c is disposed therein. An opening (not shown) is provided in the lid portion 15d, and when the plunger 15b is pushed down and rotated by a predetermined angle and released, a flange 15e provided on the outer periphery of the plunger 15b as shown in FIG. 2 is formed on the lower surface of the lid portion 15d. It abuts and holds the plunger 15b in a lowered state. When the plunger 15b is moved upward, when the plunger 15b is pushed down and rotated by a predetermined angle in the direction opposite to the initial direction and then released, the plunger 15b pops upward. When the plunger 15b is moved up and down in this state, air and fuel are pressed at the lower part thereof, and the pressed air and fuel are moved downstream by the action of the first check valve 12f and the second check valve 12g. 14 is pushed out. The hand pump 15 is used after the filter member 16 has been replaced or when draining water from the diesel filter 10.
[0028]
The case 11 is a resin-made hollow cylindrical member having an upper opening, and a screw 22 is formed on the outer periphery of the case upper end portion 11a. The case 11 and the cap 12 are connected by first storing the filtering member 16 in the case 11, fitting the cap 12 to the case upper end 11 a with the packing 21 attached to the cap lower end 12 a of the cap 12, and then The tightening member 23 is tightened according to the screw 22 on the outer periphery of the case upper end portion 11a, and both are tightened tightly. When the filter member 16 is replaced, the above procedure is reversed.
[0029]
The filter member 16 is located at the center of the fuel passage 18, which also serves as a core, an element 17 formed from paper or the like wound concentrically on the outer periphery of the fuel passage 18, and an upper end plate provided with a discharge hole. 19 and a lower end plate 20 provided with an introduction hole. The upper and lower ends of the fuel passage 18 protrude and have an upper end protrusion 18a and a lower end protrusion 18b, respectively. The height of the filtering member 16 is approximately half the height of the case 11.
[0030]
On the inner surface of the case 11, a plurality of ribs 26 for positioning the filter member 16 are provided at equal intervals from the bottom to approximately half the height, and the lower portion of the filter member 16 accommodated in the case 11 is provided. The end plate 20 is abutted against the rib 26 and positioned. The upper end plate 19 of the filter member 16 is in contact with the lower end portion 12a of the cap. When the filter member 16 is mounted in the case 11, the filter member 16 is held between the rib 26 and the lower end portion 12a of the cap. The Further, in a state where the filtering member 16 is housed in the case 11, an upper space 25 is formed in the upper part of the filtering member 16, and a lower space 27 is formed in the lower part.
[0031]
A ring-shaped member 24 having an inlet 12b at the top is suspended from the center inner surface of the cap 12, and when the cap 12 is fastened after the filter member 16 is accommodated in the case 11, the upper end protruding portion 18a of the fuel passage 18 is secured. Is closely fitted to the ring-shaped member 24, and all of the fuel introduced into the ring-shaped member 24 through the fuel supply pipe 13 and the introduction port 12 b flows into the lower space 27 from the fuel passage 18.
[0032]
The fuel that has flowed into the lower space 27 becomes a turbulent state in the lower space 27, and the contained moisture is separated, and accumulates as separated water 36 at the bottom of the lower space 27. On the other hand, the fuel from which the water has been separated changes its direction, is introduced into the element 17 from the lower end plate 20 of the filter member 16, and is filtered by the element 17 to remove impurities. The fuel from which impurities have been removed is pushed out from the upper end plate 19 into the upper space 25, and is discharged to the fuel discharge pipe 14 through the discharge port 12 c formed in the upper surface of the cap 12.
[0033]
In the lower space 27, a level switch 28 and a drain cock (not shown) are provided. The level switch 28 is a float type and includes a hollow shaft member 29 and a float 30. The hollow shaft member 29 is an elongated shaft-like member having an opening at the lower end, and an umbrella-shaped stopper 29a is provided at the tip, and a switch portion 32 to which a lead wire 33 is connected is disposed in the hollow portion. .
[0034]
The float 30 is a hollow member having an opening at the center made of resin, and a ring-shaped magnet 31 is attached to the bottom of the opening, and can be moved up and down along the shaft member 29. The float 30 moves up and down depending on the amount of the separation water 36 in the lower space 27, and the position where the float 30 abuts on the umbrella-shaped stopper 29 a is set to be a dangerous water level of the separation water 36. That is, when the amount of the separated water 36 in the lower space 27 increases and the float 30 comes to a position where it abuts against the umbrella-shaped stopper 29a, the magnet 31 attached to the float 30 moves the movable contact of the switch portion 32 to the fixed contact side. Pull and bring both contacts into contact. Then, the warning light on the driver's seat is turned on.
[0035]
When it is confirmed that the warning lamp is turned on, the driver opens a drain cock (not shown) provided at the bottom of the case 11 and discharges the accumulated separated water 36. The drain cock is performed by opening the discharge passage by manually turning the screw portion. In this case, the hand pump 15 can also be used.
[0036]
A recess 40 is formed in the bottom portion of the case 11. In the present embodiment, the recess 40 is formed on the side wall of the case 11 toward the center, but may be formed upward from the bottom of the case 11 in the axial direction.
[0037]
The recess 40 may have any shape as long as it has the same cross-sectional shape, that is, a hollow body such as a square or a circle. In the recess 40, a plurality of positioning ribs 42 are provided on the inner wall surface of the recess 40. When the fuel recirculation valve 50 is accommodated in the recess 40, the fuel recirculation valve 50 is connected to the positioning rib 42. The tip is brought into contact with and held in that position. And the internal space 44 is formed in the bottom part of the recess 40 by hold | maintaining the fuel recirculation | reflux valve 50 in the position.
[0038]
In addition, an opening 43 is provided in the side wall 41 above the recess 40 and communicated with the internal space 44, and the outer peripheral portion of the side wall 41 provided with the opening 43 functions as a water reservoir chamber. The cylindrical member 45 is provided in a form standing in the lower space 27. A check valve 48 for opening and closing the opening 43 is disposed at the bottom of the cylindrical member 45. A ring-shaped end plate 46 that functions as a spring receiver and has a hole in the center thereof is attached to the upper inner surface of the cylindrical member 45, and a relatively small space is provided between the check valve 48 and the end plate 46. A spring 47 having a weak spring force is interposed to normally close the check valve 48 and prevent the flow of fuel from the lower space 27 to the inner space 44, but the fuel recirculation valve 50 is opened to return to the inner space 44. As soon as the fuel flows in, it is opened and the recirculated fuel in the internal space 44 is introduced into the lower space 27.
[0039]
Next, the fuel recirculation valve 50 will be described with reference to FIG. The fuel recirculation valve 50 mainly includes a first casing 51 and a second casing 52. The first casing 51 is a bottomed cylindrical member, and a fuel return pipe 54 is integrally formed at the center of the bottom, and a cylindrical protrusion 55 extending toward the open end is provided inside the first casing 51. It has been.
[0040]
In addition, a packing 56 is provided in the recess on the outer periphery of the first casing 51. After the fuel recirculation valve 50 is fitted into the recess 40, the packing 56 closes the fitting between the two so that fuel leaks. Is prevented. The second casing 52 is a bottomed cylindrical member having a shallow bottom. A communication port 58 is formed in the center of the bottom portion, and a ring-shaped valve seat 57 is formed around the communication port 58. .
[0041]
The first casing 51 and the second casing 52 are formed by press-fitting the inner peripheral surface of the second casing open end 52a of the second casing 52 into the outer peripheral surface of the first casing open end 51a of the first casing 51. A casing internal space 53 is formed between both members. The first casing 51 has an open end 51a at the tip of which is formed an uneven portion including a convex portion 51b and a concave portion 51c, and a plurality of radial ribs 62 are formed at the bottom of the second casing 52. In addition, the rib 62 is inclined so as to become higher from the center toward the outer peripheral portion, and the outermost end thereof is a flat surface 62a.
[0042]
Reference numeral 61 denotes a bimetal valve, which is a thin disk-like plate body, and is sandwiched by both members 51 and 52 after the first casing 51 and the second casing 52 are integrally fitted. The pinching is performed by the convex portion 51 b at the tip of the opening end portion 51 a of the first casing 51 and the flat surface 62 a at the outermost end of the plurality of ribs 62 of the second casing 52. And the fixation of this bimetal valve 61 becomes a pinching form as shown in the upper end part of the bimetal valve 61 in FIG. However, the bimetal valve 61 is not sandwiched between the convex portion 51b of the first casing 51 and the flat surface 62a of the second casing 52 as shown at the lower end of the bimetal valve 61 in FIG. There is a portion where the recess 51 c and the rib 62 of the second casing 52 are not provided, and the fuel introduced into the internal space 53 from the fuel return pipe 54 passes through the portion where the bimetal valve 61 is not sandwiched in this way, opposite to the bimetal valve 61. It flows freely into the side space.
[0043]
The fixing of the bimetal valve 61 will be described again. When the first casing 51 and the second casing 52 are integrally fitted, the bimetal valve is placed on one of the opening end surfaces, for example, the convex portion 51b of the first casing opening end surface. 61 is placed, and the second casing 52 is fitted from above. Then, the outermost flat surface 62 a of the plurality of ribs 62 of the second casing 52 contacts the opposite side of the bimetal valve 61. When the first casing 51 and the second casing 52 are integrally fitted in this state, the bimetal valve 61 is sandwiched between the convex portion 51b of the first casing 51 and the flat surface 62a of the second casing 52. Will be.
[0044]
In a state in which the first casing 51 and the second casing 52 are integrally fitted, the tip of the cylindrical protrusion 55 provided on the first casing 51 and the ring-shaped valve seat 57 provided on the second casing 52. The length of the bimetal valve 61 is longer than the thickness of the bimetal valve 61, and even if the bimetal valve 61 is interposed between the tips of both the members 55 and 57, the bimetal valve 61 moves. Accordingly, a gap is formed.
[0045]
When the fuel is not recirculated, the fuel temperature in the internal space 44 formed in the recess 40 is substantially the same as the fuel temperature in the lower space 27 formed in the lower part of the case 11, and the communication of the second casing 52 is performed. It acts on the right side surface of the bimetal valve 61 via the port 58. The bimetal valve 61 is in a position where it abuts against the tip of a ring-shaped valve seat 57 provided in the second casing 52 when the fuel temperature in the internal space 44 is equal to or higher than a predetermined value. When the fuel temperature in the internal space 44 is lowered to a predetermined value or less, the communication passage space 59 and the casing internal space 53 are cut off and moved in the direction of the cylindrical protrusion 55 provided in the first casing 52, thereby forming a ring shape. The communication passage space 59 inside the valve seat 57 communicates with the casing internal space 53.
[0046]
The flow of the recirculated fuel will be described. When the fuel temperature in the internal space 44 is equal to or higher than a predetermined value, the communication passage space 59 and the casing internal space 53 are shut off, so that the recirculated fuel recirculates into the internal space 44. However, when the fuel temperature in the internal space 44 falls below a predetermined value, the bimetal valve 61 moves to the left, and the communication passage space 59 communicates with the casing internal space 53. Therefore, as shown in FIG. Warm fuel is introduced into the casing internal space 53 through the fuel return pipe 54 and flows into the internal space 44 through the communication passage space 59 and the communication port 58.
[0047]
Next, the recirculated fuel that has flowed into the internal space 44 opens the check valve 48 from the opening 43 provided in the upper portion of the internal space 44, and is recirculated from the cylindrical member 45 toward the upper portion of the lower space 27. In this way, since the reflux fuel is recirculated from the cylindrical member 45 toward the element 17 of the filter member 16, the warm recirculation fuel directly hits the element 17, so that the temperature of the recirculation fuel is difficult to decrease and precipitates in the element 17. The generation of easy wax can be effectively reduced.
[0048]
FIG. 4 shows another embodiment. This embodiment is different from that shown in FIG. 2 only in the means for introducing the reflux fuel into the lower space 27 from the opening 43, and the other configuration is the same as that shown in FIG. The feature is that warm fuel is recirculated to almost the entire surface of the element 17 of the filter member 16. That is, the shape of the end plate 46 for supporting the spring 47 at the upper portion of the opening 43 is changed, and the upper portion is formed in a divergent shape. By forming the end plate 46 in such a shape, the opening is formed. 43, the recirculated fuel introduced into the lower space 27 can be evenly dispersed in the upper portion of the lower space 27. As a result, the recirculated fuel is evenly dispersed by the element 17 and flows in. In all of 17, the generation of wax can be more effectively reduced. Note that the upper portion of the cylindrical member 45 may be formed in a divergent shape.
[0049]
FIG. 5 shows still another embodiment. This embodiment is different from that shown in FIG. 2 only in the means for introducing the reflux fuel into the lower space 27 from the opening 43, and the other configuration is the same as that shown in FIG. 4 shows that the recirculated fuel is distributed almost uniformly into the element 17 and flows into the element 17. However, when other parts such as a level switch 28 are disposed in the lower space 27, the cylindrical member 45. Cannot be arranged at the center of the lower space 27, and if the cylindrical member 45 has the same wide end shape, the warm fuel cannot be evenly recirculated over the entire surface of the element 17. This embodiment solves such a problem.
[0050]
That is, basically, the shape of the end plate 46 for supporting the spring 47 is changed at the upper part of the opening 43 as in the case of FIG. 4, and the upper part is formed in a divergent shape. That is, the spread inclination angle is changed on the left and right. In the example shown in FIG. 5, the cylindrical member 45 is arranged on the left side, and therefore, the end-spread shape of the upper part of the end plate 46 has a gentler right-side inclination angle than that on the left side. That is, the inclination of the right cylinder part 46a is made gentler than that of the left cylinder part 46b, and the tip of the right cylinder part 46a is extended near the end of the element 17. Further, a cylinder portion opening 46c is provided in the right cylinder portion 46a, which is directly below the fuel passage 18, and the lower end protruding portion 18b of the fuel passage 18 extends through the cylinder portion opening 46c.
[0051]
By adopting such a shape, even if the cylindrical member 45 is arranged on the left side, the recirculated fuel spreads all over the right side of the element 17 via the cylindrical portion 46a having a gentle slope formed on the right side. Further, the generation of wax in all of the elements 17 can be reduced more effectively, and the fuel flowing in from the fuel passage 18 enters the lower space 27 from the lower end protruding portion 18b extending downward from the cylindrical portion opening 46c. It can be introduced without hindrance.
[0052]
The invention of the present application is not limited to the configuration of each of the above embodiments, and can be appropriately changed in design without departing from the gist of the invention. For example, in each of the above embodiments, only a diesel filter is used as an element. Although described as an exchange type, a case in which the case and the element are exchanged at the same time may be used.
[0053]
【The invention's effect】
In the invention according to claim 1, a fuel recirculation valve is provided in the case forming the lower space, and the recirculation fuel from the fuel recirculation valve is recirculated into the lower space through the opening provided in the case, whereby the space on the upper surface of the diesel filter is obtained. Since there is no restriction on the top, it can be attached anywhere in the case forming the lower space, so that the degree of freedom of design is increased, and precipitation of waxing in the element can be reduced more efficiently. Also, The agitation of the separated water accumulated in the lower space is prevented by the recirculated fuel, and the separated water is moved to the fuel discharge pipe side. of Since the discharge is prevented, engine failure or the like due to the supply of separated water to the engine can be prevented.
[0054]
In the invention according to claim 2, a recess is formed in a part of the case forming the lower space, a fuel recirculation valve is provided in the recess, and a portion below the opening in which the recirculation fuel from the fuel recirculation valve is provided in the recess. By recirculating into the space, the diesel filter can be easily attached to the mounting space, and the fuel recirculation valve can be prevented from being damaged during the attachment, thereby improving the reliability.
[0056]
Claim 3 In the invention according to the above, by making the upper part of the opening widen, the reflux fuel can be made to flow almost uniformly over the entire circumference of the element, and the precipitation of wax in the element can be more reliably prevented. Therefore, reliability can be further improved.
[0057]
Claim 4 In the invention according to the above, by making the right and left slopes of the divergent shape different, even if the opening for recirculating the fuel is shifted from the center of the case, the recirculated fuel flows almost evenly over the entire circumference of the element. Since it is possible to prevent the precipitation of wax in the element more reliably, the reliability can be further improved.
[0058]
Claim 5 In the invention according to the present invention, by providing a check valve in the upper part of the opening, it is possible to prevent the fuel containing impurities in the internal space from flowing back to the filtered fuel side, thereby further improving the reliability. Can be made.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a fuel supply system for a diesel engine according to the present invention.
FIG. 2 is a cross-sectional view showing a diesel filter according to the present invention.
FIG. 3 is a sectional view of a fuel recirculation valve according to the present invention.
FIG. 4 is a cross-sectional view showing another embodiment of the diesel filter according to the present invention.
FIG. 5 is a cross-sectional view showing still another embodiment of the diesel filter of the present invention.
FIG. 6 is a schematic diagram of a conventional fuel supply system for a diesel engine.
FIG. 7 is a cross-sectional view of a conventional diesel filter.
[Explanation of symbols]
1 ... Injection pump 2 ... Common rail
3 ... Injector 4 ... Fuel tank
5 ... Diesel filter 6 ... Cap
7a, 7b ... Fuel return pipe 10 ... Diesel filter
11 ... Case 11a ... Upper end of case
12 ... Cap 12a ... Cap lower end
12b ... Inlet 12c ... Discharge port
12d: supply pipe mounting portion 12e: discharge pipe mounting portion
12f ... First check valve 12g ... Second check valve
13 ... Fuel supply pipe 13a, 14a ... Packing
14 ... Fuel discharge pipe 15 ... Hand pump
15a ... Pump case 15b ... Plunger
15c ... Spring 15d ... Lid
15e ... Flange 16 ... Filtration member
17 ... Element 18 ... Fuel passage
18a ... Upper end protrusion 18b ... Lower end protrusion
19 ... Upper end plate 20 ... Lower end plate
21 ... packing 22 ... screw
23 ... Fastening member 24 ... Ring-shaped member
25 ... Upper space 26 ... Rib
27 ... Lower space 28 ... Level switch
29 ... Shaft member 29a ... Stopper
30 ... Float 31 ... Magnet
32 ... Switch part 33 ... Lead wire
34 ... Drain cock 35 ... Discharge passage
36 ... Separated water 40 ... Recess
41 ... side wall 42 ... positioning rib
43 ... Opening 44 ... Internal space
45 ... Cylindrical member 46 ... End plate
46a ... right side cylinder part 46b ... left side cylinder part
46c ... Cylinder opening 47 ... Spring
48 ... Check valve 50 ... Fuel recirculation valve
51 ... 1st casing 51a ... 1st casing opening edge part
51b ... convex part 51c ... concave part
52 ... 2nd casing 52a ... 2nd casing opening edge part
53 ... Casing internal space 54 ... Fuel return pipe
55 ... Projection 56 ... Packing
57 ... Valve seat 58 ... Communication port
59 ... Communication passage space 61 ... Bimetal valve
62 ... Rib 62a ... Flat surface

Claims (5)

A case for forming an outer shell, a filtration member that have a element housed in said casing, and a lower space formed below the the filtration member, introducing fuel from said case upper part, has been introduced fuel in a diesel filter Ru flows upward from below through the said element, said fuel recirculation valve provided in the case of forming the lower space upwardly provided with an opening in said casing, said casing reflux fuel from the fuel recirculation valve diesel filter, characterized in that recirculates into the lower space to impinge directly below the element from the opening provided in the.   A recess is formed in a part of the case forming the lower space, a fuel return valve is provided in the recess, and the return fuel from the fuel return valve is returned to the lower space through an opening provided in the recess. The diesel filter according to claim 1. The diesel filter according to claim 1 or 2, wherein an upper portion of the opening is formed in a divergent shape. 4. The diesel filter according to claim 3, wherein left and right inclinations of the divergent shape are made different. The diesel filter according to any one of claims 1 to 4, wherein a check valve is provided on the downstream side of the opening.

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