KR101006042B1 - Fuel supplying device - Google Patents

Abstract

(Problem) When the fuel is pumped by a plurality of fuel pumps connected in series, the downstream fuel pump provides a compact fuel supply device which does not suck high-temperature fuel.

(Solution means) A fuel supply device having a fuel pump P ₁ P ₂ arranged in series for feeding fuel stored in a fuel tank 100 and a flow path through which fuel flows, wherein both fuel pumps ( P ₁ P ₂ ) are unitized by being connected to each other by a connecting member formed by a flow passage therein. In addition, the fuel pump P ₁ P ₂ is supported by the connecting member via the heat insulating member, and the fuel pump P ₁ P ₂ is not in direct contact with the connecting member.

Fuel supply.

Description

Fuel supply unit {FUEL SUPPLYING DEVICE}

The present invention relates to a fuel supply device having a plurality of fuel pumps for pumping fuel stored in a fuel tank and a flow path through which the fuel flows, wherein each fuel pump is disposed in series with each other through the flow path.

Patent documents 1 to 3 are examples of this kind of fuel supply device. In these fuel supply devices, liquefied gas fuel such as LPG stored in the fuel tank is pumped by two fuel pumps. Specifically, in patent document 1, a fuel supply apparatus is formed in the lower part in a fuel tank, and two fuel pumps are formed in parallel and are united by the connecting member which connects the lower parts of both said fuel pumps. In patent document 2, the fuel supply apparatus is formed below the fuel tank. Both fuel pumps here are formed in parallel in the same direction, and are arranged in series by connecting to a communication tube serving as a flow path through which fuel flows. In the fuel supply apparatus of Patent Document 3, the two fuel pumps are made in the same direction, and are formed in parallel, and then a series piping path, a parallel piping path is established, and can be switched in both series and parallel.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2005-337147

[Patent Document 2] Japanese Unexamined Patent Publication No. 2004-324554

[Patent Document 3] Japanese Unexamined Patent Publication No. 2002-339823

The fuel pump has a structure in which the fuel can be pumped by rotating the impeller disposed therein to generate a boost, but when the impeller is rotated in the fuel pump, a portion of the low pressure in the fuel flowing at high speed vaporizes. As a result, vaporized bubbles (vapors) are generated. When the vapors are collected in the flow path, a so-called vapor lock is generated in which the flow of fuel is hindered, leading to a deterioration or malfunction of the fuel pump, or the member is broken by the impact force (cavitation) when the vapor collapses. There is a problem. As described above, the vapor is generated by the vaporization of the fuel, so that the vapor is more likely to be generated at a higher temperature of the fuel.

Here, the fuel is pumped through the inside of the fuel pump. When the fuel pump is driven, drive heat is generated from the driving source, thereby raising the temperature of the liquefied gas fuel. If there is only one fuel pump used in the fuel supply device, even if the fuel is discharged while the fuel is heated by receiving the driving heat from the fuel pump, it is only circulated through the distribution pipe to the internal combustion engine. It doesn't work. However, there is a problem when two fuel pumps are arranged in series. That is, the fuel pump of the 1st stage (upstream side) sucks in the fuel which is not heated up from the fuel tank, and it is not until the state which a vapor is easy to generate | occur | produce. However, the fuel discharged from the 1st stage fuel pump is heated up by receiving the drive heat of the said 1st stage fuel pump. Therefore, since the fuel pump of the 2nd stage (downstream side) arrange | positioned in series sucks the fuel heated up, vapor is easy to generate | occur | produce in the said 2nd stage fuel pump, and there exists a possibility that the problem mentioned above will arise. If three or more fuel pumps are used, the temperature of the fuel is higher and vapor is more likely to be generated as it goes to the rear stage.

Although the fuel supply apparatus of patent document 1 is made into a compact by uniting two fuel pumps, the specific arrangement method and the fuel flow path are not prescribed. However, since the two fuel pumps are only connected at the bottom thereof, if both fuel pumps are arranged in series, the flow path between the two fuel pumps is shortened and the second stage fuel is discharged from the first stage fuel pump. It is difficult to assume that the fuel temperature drops until it is sucked into the pump. Moreover, when each fuel pump is driven, the body itself of each fuel pump will also receive the heat of the drive heat. Therefore, when each fuel pump and a connection member are in direct contact, the connection member itself can also receive heat from a fuel pump body. In this respect, the fuel is hardly cooled until it is discharged from the first stage fuel pump and then sucked into the second stage fuel pump.

On the other hand, in the fuel supply apparatus of patent document 2 or patent document 3, although two fuel pumps are arrange | positioned in series, since the formation direction is formed in parallel and is parallel, the discharge port of the 1st stage fuel pump and the 2nd stage fuel are The communication tube connecting the inlet of the pump has a constant length. Therefore, the fuel can be radiated from the communication tube portion in the process of flowing from the discharge port of the fuel pump of the first stage to the suction port of the fuel pump of the second stage. However, since the fuel supply apparatus of patent document 1 and patent document 2 is not unitized in particular, an apparatus becomes comparatively large and assembly is complicated. Moreover, although the patent document 1 and patent document 2 do not define the specific fixing (forming) method of each fuel pump or a communication pipe, generally, each fuel pump is fixed directly to a fuel supply apparatus through a support member or directly. That is, each fuel pump is in direct contact with any member. Therefore, the fuel pump having heat by the driving heat is less likely to radiate heat from the body, and the driving heat can also be transferred to the support member or the body of the fuel supply device. In this case, if the communication tube is also in direct contact with the support member or the like, heat can be received by the support member or the like, so that the fuel is difficult to cool even in the communication tube.

Therefore, this invention solves the said subject, Comprising: To provide the compact fuel supply apparatus which the downstream fuel pump does not inhale the high temperature fuel at the time of conveying fuel by the several fuel pump connected in series. The purpose.

In order to achieve the above object, the present invention described in claim 1 includes a plurality of fuel pumps for pumping fuel stored in a fuel tank and a flow path through which the fuel flows, and each fuel pump is disposed in series with each other through the flow path. In the conventional fuel supply apparatus, each said fuel pump is unitized by being connected by the connection member formed through the said flow path inside. In addition, each of the fuel pumps is supported by the connecting member through a heat insulating member, and each of the fuel pump and the connecting member is not in direct contact.

In addition, the arrangement | positioning formation direction and the number of formation of each fuel pump here, and the structure of a connection member and a flow path are not specifically limited, As long as each fuel pump is arrange | positioned in series through the flow path in a connection member, various structures are provided. It can be adopted. For example, the direction of each successive fuel pump may be reversed, and only the upper part or the lower part of each fuel pump may be connected by the connecting member. That is, the discharge port of the upstream fuel pump and the suction port of the downstream fuel pump may be connected by the connection member which connected only the upper part or the lower part of each fuel pump.

In the fuel supply device according to claim 1, in the fuel supply device according to claim 2, the connecting member includes: an upper connecting body connecting upper portions of the respective fuel pumps, a lower connecting body connecting lower portions of the respective fuel pumps; It has a vertical coupling connecting the upper connector and the lower connector. In addition, at least a predetermined amount of clearance is secured between the fuel pump and the vertical connecting body.

In this case, as long as the direction of each successive fuel pump is reversed, it is not necessary to form a flow path in the vertical connecting body. In addition, the up-and-down connection here may be one, a plurality, or a plurality of up-and-down connection according to the number of formation of a fuel pump, regardless of whether it is integrated with an upper connection and / or a lower connection. Moreover, the arrangement | positioning position of an up-and-down coupling body is not specifically limited, either, It may be provided in the planar outer peripheral part (outside of each fuel pump) of an upper coupling body and a lower coupling body, and may be formed between each fuel pump. The fact that at least a predetermined amount of clearance is secured between each fuel pump and the upper and lower couplings means that the upper and lower couplings are connected between the respective fuel pumps, except that the upper and lower couplings are formed sufficiently outside of each fuel pump, for example. Even when formed, a case where a predetermined amount of clearance is secured between each fuel pump and the vertical connecting body is considerable.

The invention according to claim 3 is the fuel supply device according to claim 2, wherein each of the fuel pumps is formed in parallel with each inlet and outlet in the same direction. In addition, an upper communication passage is formed in the upper connecting body, and a lower communication passage is formed in the lower connecting body, respectively, and an upper and lower communication passage connecting the upper communication passage lower communication channel is also formed in the upper and lower connecting bodies. It is characterized by being formed.

The present invention according to claim 4 is the fuel supply device according to any one of claims 1 to 3, wherein the connecting member is formed of a material having a low specific heat.

The present invention according to claim 5 is the fuel supply device according to claim 3 or 4, characterized in that the inlets of the respective fuel pumps are formed to be below.

According to this invention, since each fuel pump is unitized by the connection member, attachment to a fuel supply apparatus is easy and a fuel supply apparatus can be made compact. In addition, since the flow path through which the fuel flows is formed in the connecting member, it is not necessary to form a communication tube connecting the respective fuel pumps deliberately, and the number of parts and the number of assembly steps can be reduced. That is, at the time when each fuel pump is united with the connecting member, each fuel pump is in series communication. Moreover, since each fuel pump is supported through the heat insulation member in direct contact with the connection member, the connection member is never received from the fuel pump. Therefore, not only does the fuel not be heat-received from the connecting member when the fuel flows in the flow passage, but even if the fuel is heated by the upstream fuel pump, the heat of the fuel can be dissipated while flowing through the flow passage in the connecting member. have. This makes it possible to avoid the fuel pump on the downstream side from inhaling the fuel having a high temperature and to suppress the generation of the vapor. In addition, since each fuel pump is supported by the heat insulating member and is in a floating state that is not in direct contact with the connecting member, vibrations when each fuel pump is driven are also buffered by the heat insulating member and are not transmitted directly to the connecting member. In this regard, the driving sound of the fuel supply device can be suppressed (claim 1).

If the connecting member has the upper connecting body, the lower connecting body, and the up and down connecting body, the design flexibility of the flow path according to the arrangement method of the fuel pump is high while achieving compactness. In addition, since each fuel pump is only supported floating through the heat insulating member, each fuel pump may be rattling when only the upper connecting body and the lower connecting body are connected. By also having a vertical connecting body, the rattling of each fuel pump can be prevented significantly. In addition, if a gap is secured between each fuel pump and the vertical connecting body, even if each fuel pump itself has heat, heat can be reliably radiated from the body of each fuel pump (claim 2).

When the fuel pumps are formed in parallel in the same direction, the discharge port and the suction port of each fuel pump are located in the up and down reverse directions, respectively. Therefore, the fuel discharged from the discharge port of the upstream fuel pump must flow to the intake port of the downstream fuel pump at least in the up and down reverse direction. In addition, if the vertical connecting passage is formed in the vertical connecting body, the fuel passage can be lengthened. As a result, the section in which the heat of the fuel is dissipated is also long, and it is possible to more reliably avoid the intake of the fuel having a higher temperature by the downstream fuel pump (claim 3).

If the connecting member is formed of a material having a low specific heat, the thermal conductivity of the connecting member is high, so that the heat of the fuel can be more reliably radiated while fuel flows through the connecting member (claim 4).

If the inlet port of each fuel pump is downward, even if there is little fuel in a fuel tank, fuel can be sucked efficiently. In addition, the vapor as a bubble tends to gather upward in the fuel in a stationary state. Therefore, even if the vapor is mixed in the fuel discharged from the upstream fuel pump, since the vapor moves to the upper communication flow path side during the stop of the fuel supply device, the inlet of each fuel pump is lowered. Vapors do not collect well near the intake port, and the amount of vapor suction when the fuel supply device is restarted can be reduced (claim 5).

(Example 1)

EMBODIMENT OF THE INVENTION Hereinafter, although the Example of this invention is concretely demonstrated, referring appropriately to drawings, various changes are possible in the range which is not limited to this and does not deviate from the summary of this invention. 1-6, Example 1 of this invention is shown. 1 is a longitudinal side view of a fuel tank 100 equipped with a fuel supply device 1 of the present invention. As shown in FIG. 1, the fuel supply apparatus 1 is mounted to the fuel tank 100 which stores a liquefied gas fuel, such as LPG (liquefied petroleum gas), and is mounted in the horizontal direction at the front part of the trunk of an automobile, for example. It is fitted through. Specifically, the fuel tank 100 has a hollow cylindrical shape, and is mounted such that the fuel supply device 1 is slightly inclined at the lower portion thereof, and most of the upper portion of the fuel supply device 1 is located inside the fuel tank 100. It protrudes and the lower part of the fuel supply apparatus 1 protrudes slightly on the outer surface of the fuel tank 100. As shown in FIG. The fuel tank 100 is fixed in a state in which the fuel tank 100 is lifted by a predetermined amount from the floor surface F of the trunk by a total of four legs 101 in front and rear in both left and right sides thereof, and the fuel tank 100 Under the outside, a storage space covered with the cover 102 is formed. In the accommodating space surrounded by the fuel tank 100 and the cover 102, a draw valve for opening and closing the supply pipe 103 and the supply pipe 103 for supplying the liquefied gas fuel in the fuel tank 100 to an engine (not shown) which is an internal combustion engine. 104 is disposed. The supply pipe 103 is in communication with the fuel supply device 1 through the extraction valve 104 connected to the lower surface of the fuel supply device 1. The blowoff valve 104 is normally open, but is closed when filling the fuel tank 100 with the liquefied gas fuel, or when the fuel tank 100 is removed from the vehicle. Moreover, the operation knob 105 which opens and closes the extraction valve 104 is fixed to the front surface of the cover 102, and this operation knob 105 is able to open and close the extraction valve 104 manually. . Reference numeral 106 denotes an overflow prevention valve EFV which is assembled and screwed to the discharge port 52 of the pump unit 2 described later.

The fuel supply device 1 includes a pump unit 2 that sucks liquefied gas fuel and pumps it to the supply pipe 103, a bottom wall 3 fixed to the lower surface of the pump unit 2, and an outer side of the pump unit 2. The inner cylinder 4 which covers the inside, and the outer cylinder 5 which covers the outer side of the inner cylinder 4 are provided. The detailed description of the pump unit 2 is mentioned later. The bottom wall 3 is a substantially disk-shaped member, and has a fixed portion 3a to which the pump unit 2 is fixed and an outer peripheral portion 3b that is much thinner than the fixed portion 3a. 1, the pump unit 2 is fixed to the slightly eccentric position of the fixing part 3a of the bottom wall 3. As shown in FIG. The annular mounting ring 6 is joined to the inner circumference of the mounting hole for mounting the fuel supply device 1 in the fuel tank 100 by welding or the like. And in the state which passed the fixing part 3a of the bottom wall 3 to the inner peripheral surface of the said mounting ring 6, it is screwed so that the attachment ring 6 can be attached or detached freely in the outer peripheral part 3b. The outer diameter of the bottom wall 3 and the mounting ring 6 is the same.

The inner cylinder 4 is a cylindrical member having a lower surface open and having the same diameter as the fixing portion 3a of the bottom wall 3, and the lower surface opening is closed by the fixing portion 3a of the bottom wall 3. The inner cylinder 4 is screwed to the pump unit 2 in the lower part of the inner wall of the inner cylinder 4 in the state in close contact with the upper surface of the fixing part 3a of the bottom wall 3. Numeral 10 is a screw hole for screwing the pump unit 2 and the inner cylinder 4. The outer cylinder 5 is a cylindrical member whose lower surface is open and is the same diameter as the outer peripheral part 3b of the bottom wall 3, and the lower surface opening is closed by the bottom wall 3. As shown in FIG. The outer cylinder 5 is joined to the circumferential wall of this by the welding or the like. These bottom walls 3, the inner cylinder 4, and the outer cylinder 5 are formed concentrically to constitute a cylindrical body of the fuel supply device 1, and the bottom wall 3 is located outside the fuel tank 100, The inner cylinder 4 and the outer cylinder 5 protrude inside the fuel tank 100, respectively.

Further, in the lower part of the circumferential wall of the outer cylinder 5, one outer inflow hole 7 accommodated in the space between the outer cylinder 5 and the inner cylinder 4 is drilled through the inner and outer passages for the liquefied gas fuel in the fuel tank 100. Formed. In the lower part of the circumferential wall of the inner cylinder 4, the inner inflow hole 8 which accommodates the liquefied gas fuel which flowed in the outer cylinder 5 in the inner cylinder 4 is formed in the inner and outer perforated image. Two inner inflow holes 8 are formed at opposite positions in the radial direction of the inner cylinder 4. One of the inner inlet holes 8 and the outer inlet hole 7 is opened in the lowermost direction of the fuel tank 100 and faces the suction filter 50 corresponding to the suction port of the pump unit 2. Thereby, even if the residual amount of the liquefied gas fuel in the fuel tank 100 decreases, the liquefied gas fuel can be accommodated efficiently. In addition, since the fuel supply device 1 has a double structure inside and outside by the inner cylinder 4 and the outer cylinder 5, the operation sound of the pump unit 2 is transmitted to the fuel tank 100 as radiation sound. It is suppressed.

Next, the pump unit 2 will be described in detail with reference to FIGS. 2 to 6. 2 is a front view of the pump unit 2. 3 is a plan view of the pump unit 2. FIG. 4: shows the longitudinal front view of the pump unit 2, and is AA sectional drawing of FIG. 5 is a plan view of the base. FIG. 6 is an anomalous cross-sectional view in which the distribution path of the liquefied gas fuel is easily developed. FIG. In FIG. 2, the pump unit 2 includes two fuel pumps P ₁ and P ₂ for pumping liquefied gas fuel, a base 20 connecting lower portions of both fuel pumps P ₁ and P ₂ . The adapter 30 which connects the upper parts of both fuel pumps P ₁ and P ₂ , the base 20 and the adapter 30 are connected, and interposed between two fuel pumps P ₁ and P ₂ . The vertical forming wall 40 and the suction filter 50 which prevents suction of foreign matter in the liquefied gas fuel and serve as suction ports of the pump unit 2 are provided. The base 20, the adapter 30, and the vertical forming wall 40 are made of aluminum alloy. In addition, the base 20 corresponds to the lower connecting body of the present invention, the adapter 30 to the upper connecting body of the present invention, and the vertical forming wall 40 corresponds to the vertical connecting body of the present invention. 20), the adapter 30 and the vertical forming wall 40 constitute the connecting member of the present invention.

As shown in FIG. 4, the fuel pump P has the cylindrical housing 11 which covers the outer periphery, the motor 12 rotationally driven in the housing 11, and the lower caulking fixed to the lower end of the housing 11. The body 13, the disk-shaped impeller 14 rotatably formed in the lower body 13, and the upper body 15 caulkingly fixed to the upper end of the housing 11 are provided. The lower body 13 is a casing for forming a pump chamber, and the suction part 16 which has a suction port in the lower part is integrally formed. The upper part of the upper body 15 is integrally formed with the electrical connector part 18 and the discharge part 19 which has a discharge port. The electric connector portion 18 is supplied with electric power from the outside via the electric cable 53. Both fuel pumps P ₁ and P ₂ are formed parallel to each other symmetrically through the vertical forming wall 40 in a state where the suction part 16 (the suction port) is downward.

As well shown in Fig. 5, the base 20 is formed in a substantially semicircular plate shape. The radius of curvature of the circular arc surface 20a of the base 20 is approximately equal to the radius of curvature of the circumferential wall of the inner cylinder 4, and in a state in which the arc surface 20a is brought into contact with the inner circumferential surface of the inner cylinder 4. In the screw hole 10 formed by penetrating a radial direction inward from the arc surface 20a, it is screwed with the inner cylinder 4 (refer FIG. 1). In this embodiment, the screw holes 10 are formed at three points near the beginning and end of the circular arc surface 20a and near the top of the circular arc, and a secure fastening force can be secured only in the peripheral portion of the screw hole 10. The flat surface 20b is provided. Conformity 21 is a U-shaped recess for forming the EFV operating valve 55 described later, and reference numeral 22 is a mounting portion of the suction filter 50.

In addition, referring also to FIG. 3, the fixing hole 23 is formed in the outer periphery of the base 20 by penetrating the upper and lower penetrating shape at four points at substantially equal intervals along the circular arc surface 20a, and the said fixing hole 23 In the bottom wall 3 and bolts. In addition, referring also to FIG. 4, in the left and right both side portions with the vertical forming wall 40 formed at the center of the upper surface of the base 20 interposed therebetween, the fuel pump P moves from the side close to the vertical forming wall 40 toward the outer peripheral edge. The suction part receiving hole 24L * R and the cushion fixing hole 26L * R for fixing the lower body cushion 66 mentioned later are formed in parallel in parallel in this order. These suction part receiving holes 24 and cushion fixing holes 26 have the same pitch as the suction parts 16 and the projections of the cushion 66 of the fuel pump P, respectively, and have a predetermined depth dimension from the upper surface of the base 20. It is formed by drilling. In addition, two communication flow paths through which liquefied gas fuel flows are formed in the base 20 in the planar direction. Specifically, as shown in part by the hidden line (dashed line) of FIG. 5 in addition to FIG. 6, one is the lower communication flow path 27 formed through the suction filter mounting part 22, and the other is the circular arc surface ( It is the lower communication flow path 28 formed through 20a). The lower communication flow path 27 communicates with the suction part receiving hole 24L for the first fuel pump P ₁ , and the lower communication flow path 28 has the suction part receiving hole 24R for the second fuel pump P ₂ . ) Is communicated with the 1st up-and-down flow path 61D of the vertical formation wall 40 mentioned later. Moreover, the front end opening of the lower communication flow path 27 communicates with the suction filter 50 attached to the filter mounting part 22, and becomes a 1st lower communication flow path. On the other hand, the tip opening of the lower communication flow path 28 is airtightly closed by the plug 51, as shown in FIG. 2, FIG. 6, etc., and becomes a 2nd lower communication flow path.

As shown in FIG. 4, the vertical forming walls 40 are integrally formed vertically from the left and right center portions of the base 20. As shown in FIG. 5, the vertical forming wall 40 has a front and rear length that is longer in dimension than the outer diameter of the fuel pump P, and the front and rear center portions thereof are thin portions 40a that are curved inward from the left and right sides. It is. In addition, two vertical flow paths 60D and 61D through which the liquefied gas fuel flows are formed in both front and rear portions with the thin portion 40a interposed downward from the upper surface of the vertical forming wall 40. . Moreover, the annular recess 43 for O-ring formation is formed in the periphery of the upper surface opening of both up-and-down flow paths 60D * 61D. Reference numeral 44 denotes a bolt hole for bolting the vertical forming wall 40 to the adapter 30. 6, the upper and lower flow passages 61D on the rear side reach the inside of the base 20 and communicate with the second lower communication flow passage 28 of the base 20 as described above. . On the other hand, the upper and lower flow paths 60D on the front side penetrate to the lower surface of the base 20, and the lower surface opening of the base 20 serves as the discharge port 52 of the pump unit 2. Moreover, the relief valve 54 and the EFV operation valve 55 which can communicate the outer side of the pump unit 2 and the up-and-down flow path 60D directly above the discharge port 52 are formed in parallel up and down.

In FIGS. 3 and 4, the adapter 30 has a predetermined upper and lower height, and the recesses 31L · R and the both recesses 31L for the electrical connector portion 18, which are opened on the lower surface in both left and right sides. • The recessed portions 32L.R for the two left and right discharge portions 19 opening on the lower surface in the left and right direction inner side of R are formed in a recessed manner. Further, the upper surface of the concave portion 31L · R for both electrical connector portions 18 has a cable hole for communicating the electrical cable 53 connected to the electrical connector portion 18 of the fuel pump P out of the pump unit 2. (33) is formed by penetrating the inner and outer penetrating images. Abutment wall portion 34 is formed integrally with the upper surface of the vertical formation wall 40 at the central portion of the adapter 30, and although not shown, the planar shape of the abutment wall portion 34 is vertically formed with the vertical wall 40. It is formed in the same shape. That is, the front and rear center portions of the abutment wall portion 34 also have thin portions that are curved inward from the left and right outwards in the same manner as the vertical formation wall 40. The flow path through which the liquefied gas fuel flows is also formed inside the adapter 30. Specifically, in addition to FIG. 6, as shown in part by a hidden line (dashed line), two upper communication flow paths 35 占 36 formed inward from the outer circumferential surface of the adapter 30 in the plane direction are fitted. The front and rear two up-and-down flow paths 60U * 61U formed in the front and back both sides of the contact wall part 34 through the thin part of the contact wall part 34, and are formed upward. The upper communication flow path 35 communicates with the concave portion 32L for the discharge portion 19 of the first fuel pump P ₁ and the upper and lower flow paths 61U on the rear side, and becomes a first upper communication flow path. On the other hand, the upper communication flow path 36 communicates with the concave portion 32R for the discharge portion 19 of the second fuel pump P ₂ and the upper and lower flow paths 60U on the front side, and becomes the second upper communication flow path. . Moreover, the tip opening of the side surface communication flow path 35 * 36 is also airtightly closed by the plug 51. As shown in FIG.

4, the first and second fuel pumps (P ₁ and P ₂₎ is in the projecting portion of the cushion 66 is provided on the positioning state accommodated in the cushioning the fixing hole 26 of the base 20, the body (13 Lower ) And the suction part 16 are supported and fixed to the base 20 via the supporting member. Specifically, the suction part 16 of the fuel pump P is supported by inserting into the cylindrical and rubber support seal 65 arrange | positioned at the suction part receiving hole 24, and the lower body 13 is cushion fixed It is accommodated and supported by the rubber cushion 66 arrange | positioned at the hole 26. The inner diameter of the suction part receiving hole 24 is larger than the outer diameter of the suction part 16. The outer diameter of the cylindrical support seal 65 is slightly larger than the inner diameter of the suction part receiving hole 24, and the supporting seal 65 is elastically press-fitted into the suction part receiving hole 24. In addition, the inner diameter of the support seal 65 is slightly smaller than the outer diameter of the suction part 16, and the suction part 16 is elastically press-supported to the support seal 65. The cushion 66 is integrally formed downward from the lower surface of the receiving portion 66a and the vertical forming piece 66b which is integrally vertically formed upward from the outer circumference of the receiving portion 66a and the receiving portion 66a. It consists of the circular fin part 66c formed. The outer diameter of the pin portion 66c is slightly larger than the inner diameter of the cushion fixing hole 26, and the center portion of the pin portion 66c is hollow, so that the pin portion 66c of the cushion 66 is formed in the cushion fixing hole 26. It is elastically press-fitted and fixed. And when the fuel pump P is formed in the base 20, the lower surface of the lower body 13 is supported by the receiving part 66a of the cushion 66, and the outer peripheral surface of the lower body 13 is cushioned ( 66 is supported by the vertical forming piece 66b. In addition, when the fuel pump P is formed in the base 20, a slight gap exists between the housing 11 of the fuel pump P and the vertical forming wall 40, and both of them (11 · 40) Is not in contact.

Thus, in the state which formed the fuel pump P in the base 20, as shown in FIG. 4, the adapter 30 is formed so that it may coat | cover from the upper side of the fuel pump P. FIG. In practice, the abutting wall portion 34 is mounted on the vertical forming wall 40. At this time, the electrical connector portion 18 of the fuel pump P is accommodated in the recessed portion 31 for the electrical connector portion 18, and the discharge portion 19 is accommodated in the recessed portion 32 for the discharge portion 19. have. The inner diameter of the concave portion 32 for the discharge portion 19 is larger than the outer diameter of the discharge portion 19. The annular collar 57 having a predetermined height is fitted to the base portion of the discharge portion 19 from a higher heat insulating property than the adapter 30, and is mounted on the collar 57. In the cylindrical shape, a rubber seal 67 is disposed to cover the upper portion of the discharge portion 19. The lower surface of the seal 67 is opened entirely, and the communication hole 68 for fuel outflow is formed in the upper wall center part. The upper wall of the seal 67 is in contact with the upper surface of the discharge portion 19, and the communication hole 68 faces the discharge port of the discharge portion 19. Moreover, the upper and lower three-stage lip 69 which protrudes outward from this is integrally formed in the circumferential shape on the outer peripheral surface of the seal 67, and the seal 67 has a three-stage upper and lower seal structure. The inner diameter of the concave portion 31 for the electrical connector portion 18 is also larger than the outer diameter of the electrical connector portion 18, and both of them are not in contact with each other. That is, the fuel pump P is fixed to the adapter 30 through the collar 57 and the seal 67 in the discharge part 19, and the fuel pump P and the adapter 30 are not in direct contact. not.

In this state, a bolt hole (not shown) formed in the contact wall portion 34 of the adapter 30 penetrating upward and downward faces the bolt hole 44 of the vertical formation wall 40, The adapter 30, the vertical forming wall 40, and the base 20 are fixed by twisting the bolt 58 over the bolt hole and the bolt hole 44 of the vertical forming wall 40. At the same time, as shown in Fig. 6, the upper and lower flow paths 60U and 61U of the adapter 30 and the vertical flow paths 60D and 61D of the vertical forming wall 40 are also facing each other, and the upper and lower flow paths of these adapters 30 are respectively. Up-down communication flow path 60 * 61 is formed of 60U * 61U and the up-down flow path 60D * 61D of the vertical formation wall 40. FIG. Specifically, the upper and lower communication passages 61 are the second lower communication passages communicating with the suction ports of the first upper communication passage 35 and the second fuel pump P ₂ , which communicate with the discharge ports of the first fuel pump P ₁ . A first upper and lower communication flow path connecting the 28, and the upper and lower communication flow paths 60 are discharge ports of the second upper communication flow path 36 and the pump unit 2 communicating with the discharge ports of the second fuel pump P ₂ . It becomes a 2nd vertical communication flow path which connects 52. Further, an O-ring 59 is disposed in the recess 43 on the outer periphery of the communication section of the upper and lower flow paths 60U and 61U of the adapter 30 and the upper and lower flow paths 60D and 61D of the vertical forming wall 40. The liquid leak in the said part is sealed. In this way, the two fuel pumps (P ₁ and P ₂₎ is a lower portion connected by a base 20, the upper part by being connected by the adapter 30, the two fuel pumps (P ₁ and P ₂ ) is unitized in a state where they are arranged in series. Moreover, the rubber support seal 65, the cushion 66, the seal 67, and the resinous collar 57 also have a function as a heat insulating member.

Next, the mechanism by which the liquefied gas fuel is pumped in the pump unit 2 is demonstrated, referring FIG. In addition, refer to FIG. 4 suitably about the internal component of fuel pump P. FIG. First, the liquefied gas fuel stored in the fuel tank 100 passes the outer inlet hole 7 of the outer cylinder 5 of the fuel supply device 1 and the inner inlet hole 8 of the inner cylinder 4 in this order. Inflow into the inner cylinder (4). Then, when the fuel pump P is driven, the liquefied gas fuel accumulated in the inner cylinder 4 by the boosting action of the impeller 14 is pumped through the suction filter 50 serving as the suction port of the pump unit 2 ( 2) it is inhaled. The liquefied gas fuel sucked into the pump unit 2 is sucked from the inlet of the suction part 16 via the first lower communication flow path 27 of the base 20 to the first fuel pump P ₁ . The liquefied gas fuel boosted by the first fuel pump P ₁ is discharged from the discharge port of the discharge unit 19 above the pump unit 2. The liquefied gas fuel discharged from the first fuel pump P ₁ includes the first upper communication flow path 35 of the adapter 30, the first vertical communication flow path 61 in the adapter 30, and the vertical forming wall 40, The second lower communication flow path 28 of the base 20 flows in this order, and is sucked into the second fuel pump P ₂ from the suction port of the suction part 16.

At this time, it formed in such first fuel pump (P ₁₎ a liquefied gas fuel has a first fuel pump, but is raised receives the driving heat, the specific heat of the base 20 of the lower aluminum of (P ₁₎ discharged from, as the exit flow to a long communication passage is connected at the top of the pump unit (2) to the lower portion, the heat is efficiently down to a second fuel pump (P ₂₎ through a connecting member composed of a base 20 or the like. As a result, inhalation of the liquefied gas fuel having a high temperature into the second fuel pump P ₂ is suppressed. In addition, the housing 11 of the first fuel pump P ₁ is heated up in response to the driving heat of the motor 12, but there is a significant gap between the first fuel pump P ₁ and the vertical forming wall 40. By ensuring, the heat of the 1st fuel pump P ₁ itself can also be efficiently dissipated. In addition, the first fuel pump P ₁ is not directly in contact with the connecting member composed of the base 20 or the like, and is provided on the support seal 65, the cushion 66, and the seal 67 that also function as a heat insulating member. Since it is only supported in a floating state, the heat of the first fuel pump P ₁ cannot be transferred to the base 20 or the adapter 30.

The liquefied gas fuel sucked into the second fuel pump P ₂ is further boosted by the impeller 14 and again discharged from the discharge port of the discharge portion 19 above the pump unit 2. The liquefied gas fuel discharged from the second fuel pump P ₂ passes through the second upper communication flow path 36 of the adapter 30, the adapter 30, and the second vertical communication flow path 60 in the vertical forming wall 40. According to this order, it discharges from the discharge port 52 of the pump unit 2. Also in this case, the liquefied gas fuel discharged from the second fuel pump P ₂ is dissipated through the connecting member while flowing in the communication flow path, the heat of the second fuel pump P ₂ itself is also dissipated. The heat of the _double pump P ₂ is not transmitted to the base 20 or the adapter 30 as in the case of the first fuel pump P ₁ . Then, the liquefied gas fuel discharged from the discharge port 52 is pushed to the engine via the blowoff valve 104 and the supply pipe 103.

In addition, as described above, the discharge port 52 is screwed with an assembled overflow prevention valve (EFV) 106 (see FIG. 1). This overflow prevention valve 106 is elastically supported in the valve opening direction during normal operation of the pump unit 2, and the supply pipe 103 is damaged or the like so that it is abrupt between the fuel tank 100 and the supply pipe 103. When excess flow occurs due to the pressure difference, it is a check valve that prevents liquid leakage by preventing the flow of liquefied gas fuel by closing the valve against the elastic support force of the spring. However, since the fuel pump P is arrange | positioned in the fuel tank 100, the said fuel pump P becomes a flow resistance, and sufficient excess flow hardly arises. As a result, the overflow prevention valve 106 does not operate correctly (the valve is closed), and fuel may flow out of the fuel tank 100 little by little. Therefore, in the pump unit 2 of this embodiment, as shown in FIG. 2 or FIG. 6, the flow path in the pump unit 2 (second upper and lower communication) directly on the overflow prevention valve 106 (discharge port 52). An EFV actuating valve 55 is provided that enables the flow path 60 to communicate with the outside of the pump unit 2 and the inside and outside.

The EFV actuating valve 55 is also assembled and screwed to the vertical forming wall 40, a valve body (not shown) is usually elastically supported outward of the pump unit 2, and the EFV actuating valve 55 is closed. have. On the other hand, when the pressure in the flow path drops rapidly, the valve body is subjected to the pressure in the fuel tank 100 to resist the elastic bearing force of the spring and moves inward of the pump unit 2 so that the EFV operation valve 55 is opened, and the EFV It is a check valve configured to inject liquefied gas fuel directly into the flow passage from the operation valve 55. Then, when a sudden pressure difference such as excess flow occurs between the fuel tank 100 and the supply pipe 103, the EFV operation valve 55 is brought into the valve open state, and the pressurized fuel in the fuel tank 100 is increased. The excess flows directly into the flow path without passing through the fuel pump P as excess flow. As a result, the overflow prevention valve 106 is operated in a securely closed state, so that the inflow of the liquefied gas fuel to the supply pipe 103 is blocked.

In addition, directly above the EFV operation valve 55, a relief valve 54 is provided which enables the flow path (the second up and down communication flow path 60) in the pump unit 2 to communicate with the outside of the pump unit 2 and in and out. have. This relief valve 54 is also assembled and screwed to the vertical forming wall 40, a valve body (not shown) is usually elastically supported inwardly of the pump unit 2, and the relief valve 54 is closed. . On the other hand, when the pressure in the flow path rises, the valve body is moved outward of the pump unit 2 in response to the pressure, and the relief valve 54 is opened to open the liquefied gas through the relief valve 54. A check valve configured to allow fuel to flow out of the pump unit 2. That is, the communication direction of the relief valve 54 and the EFV operation valve 55 is reverse. Here, the solenoid valve which is not shown in figure is arrange | positioned at the end (downstream) of the supply pipe 103. This solenoid valve is electronically controlled by the control apparatus so that it may be kept open when the engine as an internal combustion engine is driven, and will be in a closed state when the engine is stopped. Then, when the solenoid valve is closed when the engine is stopped, and the pressure of the liquefied gas fuel existing in the flow path increases, the relief valve 54 operates in the open state under the pressure of the liquefied gas fuel in the flow path. Liquefied gaseous fuel in the pressure is released by flowing out of the pump unit 2 through the relief valve 54.

(Example 2)

7 shows Example 2 of the present invention. FIG. 7 is a longitudinal front view of the pump unit 2 corresponding to the line A-A in FIG. 3 in Example 2. FIG. The second embodiment is a modification of the supporting member for supporting the discharge portion 19 of the fuel pump P in the recessed portion 32 for the discharge portion 19 of the adapter 30. Specifically, in the first embodiment, the cylindrical seal 67 was disposed in a state of being mounted on the collar 57 having a predetermined height. In the second embodiment, the collar 57 was removed. That is, as shown well in FIG. 7, only the rubber cylindrical seal 70 is interposed between the discharge portion 19 and the adapter 30. The seal 70 of the second embodiment has an upper and lower height larger than the seal 67 of the first embodiment and is formed to be equal to the discharge portion 19, and the fuel pump P is connected to the adapter 30. At that time, the seal 70 covers the entire outer circumference from the top to the bottom of the discharge portion 19. Thus, since the whole discharge part 19 is covered by the rubber | gum seal 70 made of rubber with a higher heat insulation than the resin collar 57, between the fuel pump P and the adapter 30 more reliably. It can be insulated. In addition, since the seal 70 has a higher modulus of elasticity than the collar 57, the seal vibration of the fuel pump P can be more buffered. In addition, by removing the collar 57, the number of parts and the number of assembly steps can be reduced. Otherwise, since it is the same as that of Example 1, the same code | symbol is attached | subjected to the same member and the description is abbreviate | omitted.

(Other variations)

In Example 1 and Example 2, once the fuel discharged from the upstream fuel pump is sucked into the fuel pump on the downstream side by one time from the top to the bottom of the pump unit 2 (fuel supply device 1). Although the communication flow path which has a predetermined length is constructed by moving, it can also be constructed as a reciprocating flow path like moving the upper part and the lower part of the pump unit 2 2 or more times. For example, as shown in FIG. 8 which is a path diagram schematically showing the flow path of the fuel in the pump unit 2, the second fuel pump P2 downstream from the first fuel pump P1 on the upstream side. Up to, the fuel may be reciprocated once in the upper and lower portions in the pump unit 2. Specifically, after the inlet port of the second fuel pump P2 is disposed upward, the second lower communication flow path 28 is communicated with the first vertical communication flow path 61 and the second vertical communication flow path 60, The second upper communication flow path is communicated with the inlet port of the second vertical communication flow path 60 and the second fuel pump P2. Then, the fuel is sucked in and discharged to the first fuel pump P1 through the first lower communication flow path 27 communicating with the intake port of the pump unit 2 until it is sucked into the second fuel pump P2. , The first upper communication passage 35, the first upper and lower communication passage 61, the second lower communication passage 28, the second upper and lower communication passage 60, and the second upper communication passage 36 in this order. Accordingly, the upper and lower parts of the pump unit 2 are reciprocated by one. The discharge port of the second fuel pump P2 is connected to the discharge port of the pump unit 2 as it is. According to this, since the communication flow path in the pump unit 2 can be made longer, the heat of fuel can be further dissipated up to the 2nd fuel pump P2. At this time, although the inlet port of the second fuel pump P2 is located above the fuel supply device 1, if only the inlet port of the first fuel pump P1 is located below the fuel supply device 1, the fuel tank ( Even if there is little fuel in 100, it can suction efficiently.

In addition, not only this but the number of the upper communication flow paths in the upper coupling body, the vertical communication flow paths in the vertical coupling body, and the lower communication flow paths in the lower coupling body are three or more, respectively, so that the fuel is upstream. The flow path which reciprocates the upper part and the lower part of a fuel supply apparatus multiple times from a fuel pump to a downstream fuel pump can also be constructed. Furthermore, you may form a vertical communication flow path in a spiral shape. In addition, in the said Example 1 and Example 2, although the support seal 65 which supports the suction part 16 of the fuel pump P, and the cushion 66 which support the lower body 13 were formed as a separate body, It can also be set as the integral molded article which has a seal part and a cushion part.

As described above, in the fuel supply device 1 of the present invention, two fuel pumps P ₁ and P ₂ are connected in series with the connecting member, so that at least the driving heat of the fuel pump P is directly connected to the connecting member. Efficient heat dissipation is possible by allowing fuel to flow in the communication flow path which is not heated and is designed to have a significant length. Then, the second fuel pump in the downstream (P ₂₎ can be suppressed to a high temperature is sucked fuel. In addition, since the relief valve 54 and the EFV actuation valve 55 are also united in the attached state, the compactness is achieved. At this time, by placing the EFV actuating valve 55 directly on the overflow preventing valve 106 and reducing the distance between them, the overflow preventing valve 106 can be operated by the EFV actuating valve 55 accurately. Also, since the relief valve 54 is disposed, even when a check valve is provided to prevent the backflow of fuel, such as directly under the fuel pump P, the check valve is prevented by excessive pressure in the flow path at the time of engine stop. Digging can also be prevented.

1 is a longitudinal side view of a fuel tank equipped with a fuel supply device;

2 is a front view of the pump unit.

3 is a plan view of the pump unit.

4 is a cross-sectional view taken along the line A-A of FIG.

5 is a plan view of the base.

FIG. 6 is an anomalous cross-sectional view in which the distribution path of the liquefied gas fuel is easily developed. FIG.

FIG. 7 is a longitudinal front view of the pump unit of Example 2 corresponding to line A-A in FIG.

8 is a flow path diagram of fuel in a pump unit in another modification.

Explanation of the sign

1 fuel supply

2 pump units

3 bottom wall

4 inner tube

5 external cylinders

6 mounting ring

7 Outer inlet hole

8 inner inlet hole

11 housing

12 motor

13 lower bodybuilder

14 impeller

15 upper body

16 suction

18 Electrical connector

19 outlet

20 base

24 suction hole

26 cushion fixing hole

27 1st lower communication flow path

28 2nd lower communication flow path

30 adapter

34 abutment wall

35 1st upper communication flow path

36 2nd upper communication flow path

40 vertical forming walls

50 suction filter

54 relief valve

55 EFV Actuated Valve

60 second vertical communication flow path

Upper and lower flow paths of 60U and 61U adapters

Upper and lower flow paths of 60D and 61D vertical forming walls

61 first vertical communication flow path

65 support seal

66 cushion

67 · 70 days

100 fuel tank

103 supply pipe

104 draw valve

106 overflow valve

P ₁ first fuel pump

P ₂ second fuel pump

Claims (6)

A fuel supply device comprising a plurality of fuel pumps for pumping fuel stored in a fuel tank and a flow path through which the fuel flows, wherein each fuel pump is disposed in series with each other through the flow path, Each said fuel pump is unitized by being connected by the connection member which the said flow path penetrated inside, Wherein each of the fuel pumps is supported by the connection member via a heat insulating member, and the fuel pump and the connection member are not in direct contact with each other. The method of claim 1, The connecting member has an upper connecting body connecting the upper parts of the respective fuel pumps, a lower connecting body connecting the lower parts of the respective fuel pumps, and a vertical connecting body connecting the upper connecting body and the lower connecting body, A fuel supply device, characterized in that at least a predetermined amount of clearance is secured between the fuel pump and the vertical connecting body. The method of claim 2, Each said fuel pump is formed in parallel by making each inlet and outlet the same direction, An upper communication passage is formed in the upper connecting body, and a lower communication passage is formed in the lower connecting body, respectively, and an upper and lower communication passage connecting the upper communication passage lower communication channel is also formed in the upper and lower connecting bodies. There is a fuel supply device. 4. The method according to any one of claims 1 to 3, And the connecting member is formed of a material having a low specific heat. The method of claim 3, wherein A fuel supply device, characterized in that the intake port of each of the fuel pump is formed to be below. The method of claim 4, wherein A fuel supply device, characterized in that the intake port of each of the fuel pump is formed to be below.

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