JP6395764B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a fuel supply device that sucks up fuel from a fuel tank and supplies the fuel to equipment such as an engine.

  In a fuel supply device using a brushless DC motor as a motor for the fuel pump, maintenance parts such as a commutator and a brush are unnecessary. However, in order to control the drive of the motor, commutation control is performed according to the magnetic pole of the rotor. A drive circuit is required. At this time, if the harness connecting the control board on which the drive circuit is formed and the motor becomes long, it becomes easy to receive noise that affects the drive control. Therefore, it is desirable to mount the control board as close to the pump body as possible. .

  By the way, among the electronic components mounted on the control board, power components that control electric power such as commutation generate heat due to an electrical load during driving. Therefore, in order to perform stable control, a configuration for releasing heat is necessary so that the temperature of the control board does not rise excessively. Therefore, a fuel supply device has been proposed in which a circuit case for mounting a control board and a heat dissipation path for releasing heat of the mounted control board into the fuel are formed in a housing that houses the pump body (for example, a patent Reference 1).

JP 2001-99029 (paragraphs 0025-0040, 0045, FIGS. 1-4)

  However, in the fuel supply device in which the above-described heat dissipation path is formed, it is necessary to embed the fuel pipe in advance in a state where the fuel pipe is inserted into the metal heat dissipation plate serving as the heat dissipation path, and the structure is complicated and easy. Could not be assembled.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a highly reliable fuel supply device that is easy to assemble, has excellent heat dissipation, and high reliability.

  A fuel supply device according to the present invention includes a pump that sucks up, pressurizes and discharges fuel, a control board having a circuit surface on which electronic parts for controlling the driving of the pump are mounted, and the pump inside the fuel tank. And a housing having a partition wall for partitioning the space so that a predetermined level of fuel remains on one side, and the control board includes the circuit surface and a heat dissipation surface on the back side. Of the members constituting the casing, the partition wall holding member having the partition wall is embedded in the middle part of the thickness of the partition wall. The heat-dissipating surface is directed to the one side, and the thickness of the resin covering the heat-dissipating surface is smaller than the thickness of the resin in the main part of the partition wall. To do.

  According to the fuel supply apparatus of the present invention, the primary sealed control unit is integrally molded with the housing so as to be embedded in the wall, so that the assembly is easy, the heat dissipation is excellent, and the reliability is high. A feeding device can be obtained.

It is a fragmentary sectional view which shows the structure of the control board periphery part of the housing | casing by which the control unit was integrally molded for demonstrating the structure of the fuel supply apparatus concerning Embodiment 1 of this invention. 1 is a perspective view illustrating an overall configuration of a fuel supply device according to a first embodiment of the present invention. It is a perspective view in each before and after primary sealing for demonstrating the structure of the control unit of the fuel supply apparatus concerning Embodiment 1 of this invention. It is the perspective view and side view of a lower housing | casing for demonstrating the structure of the fuel supply apparatus concerning Embodiment 1 of this invention. It is a fragmentary sectional view which shows the structure of the part by which the control unit for demonstrating the structure of the fuel supply apparatus concerning Embodiment 2 of this invention was integrally molded. It is a top view of the lower housing | casing for demonstrating the structure of the fuel supply apparatus concerning Embodiment 2 of this invention. It is the side view and bottom view of a lower housing | casing for demonstrating the structure of the fuel supply apparatus concerning Embodiment 2 of this invention.

Embodiment 1 FIG.
1-4 is for demonstrating the structure of the fuel supply apparatus concerning Embodiment 1 of this invention, and FIG. 1 is the case where the control unit which is the characteristic part of this invention is integrally molded. FIG. 1A is a partial cross-sectional view taken along line AA of FIG. 4A described later, and FIG. 1B is a diagram of FIG. 4A. It is a fragmentary sectional view by the BB line. 2 is a perspective view showing the overall configuration of the fuel supply device, and FIGS. 3A and 3B are diagrams for explaining the configuration of the control unit in which the drive circuit is formed. It is a perspective view in the state before giving a stop and after giving. FIG. 4 shows the overall structure of the lower housing in which the control unit is integrally molded. FIG. 4 (a) is a perspective view and FIG. 4 (b) is a side view.

  As shown in FIG. 1, the fuel supply device 1 according to the first exemplary embodiment of the present invention is such that the primary-sealed control board 30 (control unit 3) is integrally formed with the lower housing 8. Prior to the detailed description, the configuration of each part of the fuel supply device 1 will be described.

  The fuel supply device 1 according to the first embodiment of the present invention is assumed to be inserted from an opening on the bottom surface of a fuel tank for a vehicle (not shown) to close the opening and be attached so that the main body portion rises from the bottom surface. It is a thing. Then, as shown in FIG. 2, the lower housing 8 having a disk-shaped lid portion 8 b that serves as a lid that closes the opening and the cylindrical side wall portion 8 w, and the lower end side is inside the side wall portion 8 w of the lower housing 8. An upper housing 7 (together with housing 9) to be fitted and a pump unit 4 housed in the lower housing 8 are provided.

  The pump unit 4 uses a motor that is a brushless DC motor as a rotational drive source, and rotates an impeller that is coaxially connected to the motor, thereby sucking up fuel such as gasoline, pressurizing and discharging the fuel.

  In order to drive the motor of the pump unit 4, a drive circuit that performs commutation control in accordance with the magnetic poles of the rotor is necessary as described in the background art. Therefore, as shown in FIG. 3A, for example, a control substrate 30 in which an electronic component 32 including a power component 32p and terminals 33a and 33b are mounted on a circuit base 31 such as a glass epoxy substrate by solder reflow, for example. A drive circuit is configured. Note that the terminals 33a and 33b are fixed in the mold in a state of being connected to the lead frame when sealing, which will be described later, and a portion exposed from the sealing body 34 after the sealing is completed or bent. It is usually applied. That is, in the mounting stage of the electronic component shown in FIG. 3A, it should be in a state where it is originally connected as a lead frame, but for the convenience of drawing, a state after separation is shown.

  In the state of FIG. 3A, the circuit surface 30f of the control board is uneven due to the mounting of the electronic component 32 and the like. However, in the control unit 3 according to the fuel supply device 1 according to the present embodiment, as shown in FIG. 3B, the ends of the terminals 33a and 33b are sealed by a sealing body 34 of a thermosetting resin such as an epoxy resin. The entire control board 30 (six sides) is sealed (primary sealing) except for the portion. At that time, the main surface 3f is formed so as to be flat by embedding the unevenness of the circuit surface 30f so as not to apply a force that damages the electronic component 32 at the molding pressure at the time of integral molding described later. Yes. Further, a portion other than the portion where the terminals 33a and 33b are exposed, that is, the sealing body 34 portion is a flat plate material. In FIG. 3B, the end of the sealing body 34 is drawn to be square, but in reality, the sealing body 34 is rounded to avoid stress concentration on the continuous wall material with the control unit 3 in between. Is attached.

  The upper housing 7 is formed by molding a thermoplastic resin such as acetal resin (POM: Poly Oxy Methylene). In addition, a primary filter (not shown) that removes foreign matters such as iron powder floating in the fuel sucked up by the pump unit 4, a high-pressure filter (not shown) that removes fine foreign matters generated in the pump unit 4, etc. It is stored. Further, a pressure regulator (back pressure adjusting valve) (not shown) for returning excess fuel from the pipe in order to adjust the fuel pressure in the pipe is housed in the upper housing 7. In addition, a fuel detector (not shown) for detecting the amount of fuel in the tank is externally attached to the upper housing 7.

  The lower casing 8 is also formed by molding acetal resin (thermoplastic resin) in the same manner as the upper casing 7, and the disc-shaped lid portion 8b functions as a lid that partitions the inside and outside of the fuel tank. A packing groove 8bd for packing installation is formed on the outer peripheral side of the lid portion 8b in order to ensure sealing performance with the fuel tank. Moreover, as shown in FIG. 4, the cylindrical side wall part 8w provided so that it may stand up from the cover part 8b forms the storage space Rf which dams up and stores the fuel returned from the piping. That is, the side wall 8w is a partition wall that partitions the space in the fuel tank so that a predetermined level of fuel remains on the storage space Rf side. As a result, even when the vehicle is tilted when the fuel in the fuel tank is near empty and the fuel is biased to one side, the liquid level Lf at a certain level can be maintained, and the sucking performance can be ensured. it can.

  A discharge port 5 for pumping fuel discharged from the pump unit 4 to the engine side is also formed integrally with the lower housing 8. Furthermore, as shown in FIG. 1, the control unit 3 described above is embedded as a part of the side wall portion 8w. At that time, the terminals 33a and 33b are projected inside the resin member, and the internal connector 8si for electrically connecting the pump unit 4 and the control unit 3 is electrically connected to the control unit 3 and the external circuit. Are simultaneously formed.

  Although the lower housing 8 has a complicated structure as described above, dimensional accuracy and structural strength for ensuring sealing performance and connectivity with other devices are required. Therefore, the pressure (for example, injection molding pressure) required to cause the resin to flow at the time of molding increases compared to the case of molding a simple shape. On the other hand, as described above, the control unit 3 embedded in the lower housing 8 fills the unevenness of the electronic component 32 with the sealing body 34 made of a thermosetting resin, and the main surface 3f and the back surface 3r on the opposite side are It is formed flat. Therefore, the electronic component 32 on the circuit surface 30f and the wiring that connects them can be integrated with the lower housing 8 by insert molding without damaging them.

  Here, as in the conventional case, when the control board is installed on the surface with the molded product after molding, even if the control board after installation is sealed with resin, the boundary between the sealed resin and the molded product is The structural connection is weak compared to the resin continuous part. Therefore, in order to maintain the bending rigidity in the direction extending from the main surface of the control board, it is necessary to increase the thickness of the molded product itself on the side where the control board is installed. As a result, since the thickness of the resin on the heat radiating surface side becomes thick and heat conductivity cannot be secured, it is necessary to separately embed a metal heat radiating plate for heat radiation as in Patent Document 1.

  However, in the fuel supply device 1 according to the first embodiment of the present invention, the control unit 3 is flattened by the thermosetting resin sealing body 34. Thereby, when the lower housing 8 is molded, the control unit 3 can be arranged in the middle portion of the thickness of the structural member of the lower housing 8 by insert molding of the control unit 3. Therefore, the structural members constituting the lower housing 8 are continuous without interruption in the direction extending from both sides of the control unit 3, that is, the main surface 3f and the back surface 3r.

  That is, since the structural member of the lower housing 8 is continuous from the peripheral portion so as to sandwich the control unit 3 from both sides in the thickness direction, both the main surface 3f side and the back surface 3r side members are structural members for bending rigidity. Will play a role. As a result, even if the thickness of one of the members on the main surface 3f side and the back surface 3r side is reduced, if the other thickness is secured to some extent, the member extends in the direction extending from the main surface 3f of the control unit 3. The bending rigidity of can be maintained.

  The control unit 3 is embedded in the side wall 8w serving as a partition wall for forming the storage space Rf. Since the liquid level is different between the inside and the outside of the storage space Rf, the fuel may be strongly struck to the side wall 8w when the speed changes during acceleration or stop, and the side wall 8w The strength (thickness tb) is required as a partition wall that can withstand. However, in the fuel supply device 1 according to the first embodiment, the thickness tr on the surface side facing the storage space Rf in which the liquid level Lf is secured is thinner than the continuous surrounding thickness, that is, the thickness tb as the partition wall. did. On the other hand, rigidity is ensured by making the thickness tf on the main surface 3f side thicker than the thickness tr on the back surface 3r side.

  In FIG. 1A, the thickness ts of the partition wall is thicker than the thickness of the partition wall because it is necessary to form the internal connector 8si, but the above-described thickness relationship is necessary for the internal connector 8si. Regardless of the thickness, it is a necessary thickness as a partition wall. Further, in both FIG. 1A and FIG. 1B, the thickness of the portion where the resin covering both surface portions of the control unit 3 merges is naturally the thickness tr on the back surface 3r side and the thickness tf on the circuit surface 30f side. It is natural that it becomes thicker than the sum. Moreover, the thickness of the side wall part 8w is not necessarily uniform, and the case where there exists a change is also assumed. Therefore, the thickness tb as the partition wall means the thickness of the main portion as the side wall portion 8w in the peripheral portion continuous in the circumferential direction shown in FIG. That is, it is the thickness of the part required as a wall material in which a piping member, a wiring member, etc. are not embedded. Since the thickness tr on the back surface 3r side also contributes to the strength, the thickness tf on the main surface 3f side may be thinner than the thickness tb as the partition wall.

  On the other hand, the thermosetting resin constituting the sealing body 34 is not continuous with the resin constituting the lower housing 8 in the extending direction of the main surface 3f even if the thermosetting resin itself has rigidity. As mentioned above, the connection is weak. Therefore, like the situation at the boundary between the sealed resin and the molded product in the prior art, it does not contribute to the strength as a wall material. Therefore, the main surface 3f side may be increased in thickness beyond the thickness necessary for filling the unevenness to protect the electronic component 32, but the thickness on the heat radiating surface 30r side is improved in heat dissipation. Therefore, it is desirable to make it as thin as possible. Further, in Embodiment 1 and Embodiment 2 described later, an example in which the main surface 3f is flattened by the sealing body 34 is shown, but the present invention is not limited to this. When the lower housing 8 is molded, if a force that damages the electronic component 32 is not applied and there is no problem in the flow of the resin during molding, the unevenness may be left.

  As a result of the above, the sum of the thickness of the sealing body 34 on the heat radiating surface 30r side and the thickness tr of the side wall 8w on the heat radiating surface 30r side, that is, the heat radiating surface 30r of the control board 30 and the fuel in the storage space Rf The thickness of the resin material interposed between them is made thinner than the thickness tb required for the partition wall. As a result, the heat radiating surface 30r conducts heat between the heat in the storage space Rf in which the level of the liquid level Lf is secured at a predetermined level or more via the resin thinner than the thickness tb of the main portion of the side wall 8w. A path is formed. That is, it is possible to efficiently release the heat generated in the electronic component 32 (particularly, the power component 32p) of the control unit 3 into the fuel existing in the storage space Rf without impairing the rigidity.

  At this time, the height of the liquid level Lf is preferably higher than the height of the control board 30, but at least the position of the electronic component 32 is higher than the position where the power component 32p having a large heat generation amount is disposed. Then, the control board 30 can be efficiently cooled.

Embodiment 2. FIG.
The fuel supply device according to the second embodiment of the present invention is obtained by changing the position where the control unit is embedded with respect to the fuel supply device according to the first embodiment. Other configurations and operations are the same as those in the first embodiment, and the description of the same parts is omitted.

  For example, FIG. 3 used in the first embodiment is incorporated in the second embodiment. In addition, in FIG. 2 described in the first embodiment, portions other than the portion where the control unit 3 is drawn are incorporated in the second embodiment. FIGS. 5 to 7 are for explaining the configuration of the fuel supply apparatus according to the second embodiment of the present invention. FIG. 5 is a case in which a control unit which is a characteristic part of the present invention is integrally molded. FIG. 7 is a partial sectional view taken along line CC of FIG. 6 to be described later. 6 is a plan view of the lower housing, and FIGS. 7A and 7B are a side view and a bottom view of the lower housing.

  Also in the fuel supply device 1 according to the second embodiment, the lower housing 8 is formed by molding acetal resin (thermoplastic resin), like the upper housing 7, and is formed on the outer peripheral side of the lid portion 8b. In order to ensure the sealing performance with the fuel tank, a packing groove 8bd for packing installation is formed. And, in order to ensure the sucking performance, even when the fuel in the tank is reduced to near empty and biased, the liquid level Lf higher than the liquid level of the entire tank can be maintained, as shown in FIG. The lid portion 8b and the cylindrical side wall portion 8w form a storage space Rf for storing the fuel returned from the pipe. A discharge port 5 for pumping fuel discharged from the pump unit 4 to the engine side is also formed integrally with the lower housing 8.

  The difference from the fuel supply apparatus described in the first embodiment is that the control unit 3 is embedded as a part of the lid portion 8b. At that time, the terminals 33a and 33b are bent in different directions so as to be substantially perpendicular to the circuit surface 30f, and the control unit 3 has a Z-shape. Then, the internal connectors 8si and the power feeding portion 8sx are formed at the same time so that the terminals 33a and 33b protrude inside the resin member.

  As described in the first embodiment, the lower housing 8 is required to have dimensional accuracy and structural strength, but the lid 8b needs to function as a structural material for the fuel tank. The required thickness tb is thicker than the side wall portion 8w. Therefore, for example, when a control board is installed on the surface of the lid portion 8b after molding, the thickness of the resin on the heat radiating surface side becomes thicker than when it is installed on the side wall portion 8w, and heat dissipation becomes more difficult.

  However, in the fuel supply device 1 according to the second embodiment of the present invention, the control unit 3 is flattened by the thermosetting resin sealing body 34, and the thickness of the structural member of the lower housing 8 is increased by insert molding. Embedded in the middle part. That is, since the structural member of the lid portion 8b is continuous from the peripheral portion in the entire circumferential direction so as to sandwich the control unit 3 from both sides in the thickness direction, both the main surface 3f side and the back surface 3r side members are resistant to bending rigidity. It will play a role as a structural member. Therefore, even if the thickness on the back surface 3r side where heat dissipation performance is required is reduced, the other thickness can be secured to some extent, and the bending rigidity in the direction extending from the main surface 3f of the control unit 3 can be maintained.

  Even when embedded in the lid portion 8b, the thickness of the portion where the resin covering both surface portions of the control unit 3 merges is naturally the sum of the thickness tr on the back surface 3r side and the thickness tf on the circuit surface 30f side. It is natural to get thicker. Moreover, the thickness of the cover part 8b is not necessarily uniform, and a case where there is a change is also assumed. Therefore, the thickness tb as the partition wall means the thickness of the main portion as the lid portion 8b in the peripheral portion continuous in the radial direction shown in FIG. That is, it is the thickness of the portion where the piping member, the wiring member, etc. are not embedded. Also in the second embodiment, since the thickness tr on the back surface 3r side also contributes to the strength, the thickness tf on the main surface 3f side may be thinner than the thickness tb as the partition wall.

  Further, the sum of the thickness of the sealing body 34 on the heat radiating surface 30r side and the thickness tr of the lid portion 8b on the heat radiating surface 30r side, that is, between the heat radiating surface 30r of the control board 30 and the fuel in the storage space Rf. The thickness of the resin material to be made was made thinner than the thickness of the surrounding cover material which is the partition wall (thickness tb required as the partition wall). As a result, a heat conduction path is formed between the heat radiation surface 30r and the fuel in the fuel tank through the resin thinner than the thickness tb of the main portion as the partition wall. That is, it is possible to efficiently release heat generated in the electronic component 32 (particularly, the power component 32p) of the control unit 3 into the fuel existing in the fuel tank without impairing rigidity.

  As described above, according to the fuel supply device 1 according to the first and second embodiments of the present invention, the pump (pump unit 4) that sucks up, pressurizes and discharges the fuel and the drive of the pump (pump unit 4) are controlled. The control board 30 having the circuit surface 30f on which the electronic component 32 is mounted and the pump (pump unit 4) are held at a predetermined position inside the fuel tank, and one side (in the storage space Rf or the fuel tank) ) And a housing 9 having a partition wall (side wall portion 8w or lid portion 8b) for partitioning the space so that a predetermined level of fuel remains, and the control board 30 includes a circuit surface 30f and a heat radiating surface 30r on the back side thereof. The entire substrate to be included is sealed with a sealing body 34 made of a first resin (for example, a thermosetting resin such as an epoxy resin), and among the members constituting the housing 9, the partition wall (side wall portion 8 w or lid portion 8 b). ) The wall holding member (lower housing 8) is made of a second resin (for example, the control substrate 3 sealed with the control unit 3) embedded in the middle portion of the partition wall (side wall portion 8w or lid portion 8b). This is an integrally molded product made of a thermoplastic resin such as POM, and the thickness of the resin (tr + the thickness of the sealing body 34) covering the heat radiating surface 30r while the heat radiating surface 30r faces one side (in the storage space Rf or the fuel tank). ) Is made thinner than the resin thickness tb of the main portion of the partition wall (side wall portion 8w or lid portion 8b), so that the strength as the partition wall is not impaired, and the heat dissipation surface 30r and the fuel are not damaged. The thickness of the intervening resin can be made thinner than the thickness tb required for the partition wall. In addition, since the control substrate 30 is entirely sealed with the sealing body 34 (obviously, the tips of the terminals 33a and 33b are exposed) and packaged as the control unit 3, it can be easily integrally molded as a casing. That is, it is possible to obtain a fuel supply device that is easy to assemble, has excellent heat dissipation, and high reliability.

  In particular, the pump (pump unit 4) is equipped with a brushless DC motor as a drive source, and at least one of the plurality of electronic components 32 is a power for performing commutation control in accordance with the magnetic pole of the rotor of the brushless DC motor. If it is the component 32p, the emitted-heat amount of the control board 30 is large compared with the motor with a brush. Therefore, the efficient heat dissipation effect by the structure mentioned above becomes more remarkable.

  Since the circuit surface 30f has unevenness caused by mounting the electronic component 32 and is flattened by the sealing body 34, the influence on the electronic component 32 at the time of integral molding is less than when the unevenness is left. Moreover, the flow of the resin is improved, and the integral molding itself can be performed smoothly.

  Since the first resin constituting the sealing body 34 is a thermosetting resin and the second resin constituting the lower housing 8 is a thermoplastic resin, the control unit 3 is integrated with the lower housing 8. It is easy to withstand the molding temperature and pressure at the time of molding, and the flexibility of molding conditions as an integral molding is improved.

  According to the fuel supply device 1 according to the second embodiment, the partition wall holding member (lower housing 8) is attached to the opening on the bottom surface of the fuel tank, and the partition wall is a lid of the opening. Therefore, it is possible to obtain a highly reliable fuel supply device that is easy to assemble, has excellent heat dissipation properties, and does not impair the strength required as a lid material.

Alternatively, according to the fuel supply device 1 according to the first embodiment, the partition wall holding member (lower housing 8) has a cylindrical shape that forms the storage space Rf for maintaining the liquid level Lf of the fuel above a certain level. Since the part (side wall part 8w and lid part 8b) is provided and the partition wall is a part (side wall part 8w) corresponding to the side wall of the cylindrical part, assembly is easy without impairing the strength required for the side wall. Thus, a fuel supply device having excellent heat dissipation can be obtained.

  At that time, the position of the liquid level Lf is at least the position of the power component 32p, more preferably, the position covering the control board 30, so that heat can be efficiently released into the fuel.

1: fuel supply device, 3: control unit, 4: a pump unit, 5: discharge port, 7: upper casing, 8: a lower housing (partition wall held member), 8b: lid (partition wall), 8w: Side wall part (partition wall), 9: housing , 30: control board, 31: circuit substrate, 30f : circuit surface, 30r : heat dissipation surface, 32: electronic component , 32p: power component, 33a, 33b: terminal, 34 : sealing body

Claims (6)

A pump that draws and pressurizes fuel and discharges it;
A control board having a circuit surface on which electronic components for controlling the driving of the pump are mounted;
A housing having a partition wall for partitioning the space so that a predetermined level of fuel remains on one side while holding the pump inside the fuel tank,
The control board is sealed with a sealing body made of a first resin, the entire board including the circuit surface and the heat radiation surface on the back side thereof,
Of the members constituting the casing, the partition wall holding member having the partition wall is an integrally molded product of a second resin in which the control board is embedded in an intermediate portion of the thickness of the partition wall, and the heat dissipation surface Toward the one side, and the thickness of the resin covering the heat radiating surface is smaller than the thickness of the resin in the main part of the partition wall. The pump is equipped with a brushless DC motor as a drive source,
2. The fuel supply device according to claim 1, wherein at least one of the electronic components is a power component for performing commutation control in accordance with a magnetic pole of a rotor of the brushless DC motor.   3. The fuel supply device according to claim 1, wherein unevenness caused by mounting of the electronic component is flattened by the sealing body on the circuit surface.   The said partition wall holding member is attached to the opening part of the bottom face of the said fuel tank, Comprising: The said partition wall is a part corresponded to the cover of the said opening part, The any one of Claim 1 to 3 characterized by the above-mentioned. The fuel supply device according to claim 1.   The partition wall holding member is provided with a cylindrical portion that forms a storage space for maintaining a liquid level of the fuel above a certain level, and the partition wall is a portion corresponding to a side wall of the cylindrical portion. The fuel supply device according to any one of claims 1 to 3, wherein The first resin is a thermosetting resin,
6. The fuel supply device according to claim 1, wherein the second resin is a thermoplastic resin. 7.

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