JPH1061520A - Device for carrying fuel from reservoir tank to internal combustion engine of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing cost and constitution space of a device for carrying fuel from a reservoir tank to the internal combustion engine of an automobile. SOLUTION: A fuel carrying pump 3 forms a constitution unit with a pump 5 carrying air. The suction side of the pump carrying air is connected with a brake force booster of an automobile to generate negative pressure. The carrying pump 3 and the pump 5 carrying air are coaxially arranged, are arranged within a common casing 1 and are revolved and driven by a common drive shaft 15. The pump carrying air which is arranged within the common casing 1 of the carrying pump is constituted as a vane pump and has a rotor which is supported within the casing 1 and is revolved and driven. A rotor 51 is provided with a guide slit receiving many pages 61. The tip part which faces the axial and external side of the vanes 61 tightly slides along the wall of a pump chamber 7 of the vane pump 5 which is eccentrically arranged for a rotor shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for transferring fuel from a storage tank to an internal combustion engine of a motor vehicle,
It has a transfer pump, in particular a gear pump, connected in a transfer conduit from the storage tank to the internal combustion engine, the transfer pump having at least one pump chamber in the pump housing and having a rotationally driven displacement member. The displacement member transfers fuel from a suction chamber connectable to a storage tank to a pressure chamber connectable at least indirectly to the internal combustion engine.

[0002]

2. Description of the Related Art A device of the above type is formed by a fuel transfer pump, which is preferably driven by an internal combustion engine, which draws fuel from a storage tank and transfers it to an internal combustion engine or a high-pressure injection pump provided on the internal combustion engine. DE2709
No. 913C2 discloses a gear transfer pump suitable for transferring fuel from a storage tank to an internal combustion engine, which has a pump chamber in a casing, in which a pair of rotationally driven and intermeshing gears are engaged. A gear is arranged which conveys the conveying medium (eg fuel) from the suction chamber to the pressure chamber along a conveying passage formed between the end face of the gear and the wall of the pump chamber. Furthermore, it is known for motor vehicles to provide a vacuum pump in the motor vehicle for generating a negative pressure for the motor vehicle brake booster. The vacuum pump is preferably driven by an internal combustion engine and is likewise mounted on the internal combustion engine or a high-pressure pump. However, this known system is configured as a separate component group and thus requires significant component space and manufacturing costs.

[0003]

SUMMARY OF THE INVENTION It is an object of the invention to reduce the construction space and the production costs in the device described at the outset.

[0004]

The object of the invention has been achieved by a device having the features of claim 1.

[0005] The device according to the invention is characterized in that the pump is a constituent unit and the fuel transport pump and the air transport pump acting as a vacuum pump are advantageously arranged in a common pump housing. This has the advantage that the required construction space is significantly reduced. Furthermore, the production costs and the weight of the pump unit are reduced. Since in this case only one common pump casing is required. It is particularly advantageous in this case that the pump devices, which are preferably designed as gear pumps and vane pumps, are arranged one after the other in the axial direction. This allows the use of only one common drive shaft, besides reducing the construction dimensions. In this case, the drive shaft only needs to be connected to the camshaft. This connection takes place in an advantageous manner by means of an elastic connecting element in the form of a groove-fitting disc connection (elastic fitting disc). This coupling member compensates for positional errors between the shaft ends and also makes it possible to isolate vibrations between the camshaft of the internal combustion engine and the drive shaft of the pump. In this case, the gear transfer pump acts as another hydraulic shock absorber between the vane pump rotor and the camshaft. In addition, the force coupling between the camshaft and the drive shaft acts as a target break point when one of the pumps or the drive shaft locks up abruptly, thereby preventing the pump or the drive shaft from being mechanically broken.

[0006] Because the drive shaft and the rotor of the vane pump are supported in an advantageous manner on the cylindrical web of the pump casing, the drive shaft transmits only the drive moment to the vane pump, but not its lateral forces. The drive shaft can be correspondingly slender. Furthermore, the outer surface of the cylindrical casing web, which serves as a sliding bearing for the rotor, and the pump chamber wall, which serves as the vane running surface of the vane pump, can be machined in one working process. This reduces manufacturing costs and reduces the position errors that occur. In this case, the rotor and casing of the vane pump can be configured as an aluminum die-cast product. This, besides reducing weight, both components have the same coefficient of thermal expansion,
This has the advantage that the indentations and holes provided in the housing are formed together by casting techniques. The aluminum component can be hard anodized for protection against wear. In order to increase the effective length of the vanes, the vanes slidably guided in the slits of the rotor are advantageously arranged at an angle to the radial plane of the rotor. A further advantage is achieved in that the fuel passage and the lubricant passage inside the pump housing are formed in the form of a push-in deformation, and the pump housing, and thus the pump chamber and the passage, are closed by a thin casing cover. In this case, the device is flanged to the cylinder head of the internal combustion engine to be supplied with fuel, and a connection hole (pressure side) for connecting the fuel back from the internal combustion engine and for supplying and connecting the fuel to the internal combustion engine is provided. It is particularly advantageous if the hoses are in direct contact with one another and the additional hose connection is omitted. The return from the internal combustion engine is carried out to the storage tank via a transport device. The pressure control of the conveyor is effected in a simple manner by means of a pressure limiting valve. The pressure limiting valve is arranged in a connecting passage opening into the return conduit between the pressure passage and the return passage.

A lubricant supply device common to both pumps is connected to the lubricant circuit of the internal combustion engine via a connection hole in the pump casing. In this case, the lubricant holes are inclined with respect to the casing and displaced from the lubricant holes in the flange, so that the supply of the lubricant is restricted. The lubricant passes through the pumping chamber of the vane pump through the indentation in the sliding bearing surface and / or through a hole in the rotor and reaches the end of the pump casing opposite to the camshaft, where it re-lubricates the internal combustion engine. Spills into the agent circuit.

Another advantage is achieved by a geometry-constrained connection between the drive shaft and the driven gear of the transport pump. This connection is a pin inserted in the side hole of the drive shaft,
This can be done by means of a form-fitting joint, rolled or milled form-fitting teeth or mating keys mounted on the drive shaft.

In order to limit the supply of fuel to the fuel delivery pump and thus the maximum delivery of the delivery pump, it is possible to selectively provide a constriction, for example a constriction in the suction line, for example a suction hole.

Advantageously, a groove is provided in the shaft seal ring separating the medium, the fuel and the lubricant on the drive shaft, and this groove is formed such that a pressure difference is generated toward the fuel. It is to be. This ensures that only the lubricant reaches the fuel system if the seal in the shaft seal ring is impaired, but that the fuel never reaches the lubricant circuit and that the lubricant is not diluted in the lubricant circuit.

[0011] Further advantages of the invention and other advantageous features of the invention are disclosed in the description, drawings and claims.

[0012]

1 to 4 show a device for transporting fuel from a storage tank, not shown, to the internal combustion engine of a motor vehicle, also not shown, or to a high-pressure injection pump, only those components which are important to the invention. It is shown. The device has a pump casing 1 in which a fuel transport pump configured as a gear pump 3 and a pump for transporting air (hereinafter referred to as a negative pressure pump) configured as a vane pump 5 are arranged. Have been.

In this case, the transport pump may alternatively be configured as another positive displacement pump, for example a roller pump. The pump casing 1 has a circular notch therein, which forms a pump chamber 7 of the vane pump 5 which opens toward one end face 9 of the pump casing 1 and which is radially inwardly connected to the pump chamber 7. On the other hand, it is limited by a cylindrical casing web 11 arranged eccentrically.
An axial through hole 13 is provided in the casing web 11, and a drive shaft 15 is rotatably guided in the through hole 13. The drive shaft projects from the pump casing 1 in a direction opposite to the end face 9. Drive shaft 15
On the free end protruding from the pump casing 1, a driving disk 17 is press-fitted. This entrained disk 1
7 is provided with a groove for receiving an elastic continuous member in the form of a mating key 19. The end of the mating key 19 protruding from the continuous disk 17 is engaged in a corresponding notch in the camshaft of the internal combustion engine, not shown, in a form-locking connection. The free end of the camshaft is arranged in alignment with the drive shaft, and the rotational movement of the camshaft is transmitted to the drive shaft 15 via the elastic connecting member 19 and the entraining disk 17.

The pump casing 1 has, on a second end face 17 facing the entraining disk 17, a notch forming an elliptical pump chamber 23 of the gear pump 3. The notch is separated from the pump chamber 7 by a casing intermediate wall, and the drive shaft 15 passes through the notch. In this case, the first gear 25 of the pair of gears meshing with each other at the end faces, which is on the drive shaft 15,
It is coupled to the drive shaft by a shape constraint using a pin 27 press-fitted therein. The second gear (not shown) is disposed obliquely shifted with respect to the first gear 25 when viewed in a side view (FIGS. 2 and 3). In this case, the second
The gear shafts are also supported in the pump casing 1. Alternatively, it is also possible to use a cylindrical casing web instead of a shaft for supporting the second gear. In this case, the upper pump chamber section radially connected to the gear at the level of the meshing part is the suction chamber 29 of the gear pump 3.
And the lower pump chamber section facing the suction chamber 29 at the meshing portion forms the pressure chamber of the gear pump 3. The suction chamber 29 is provided with a suction hole 33 in the pump casing. This suction hole 33 is connected to a fuel conduit from the storage tank. In this case, the suction hole 33 can also be provided with a constriction in order to limit the maximum volume flow by means of a "suction restriction". A pressure passage 35 extends from the pressure chamber 31. The pressure passage 35 is formed by a press-in deforming portion on the end face 21 of the pump casing 1 and the web 37 of the pump casing 1
Extending to In parallel to the pressure passage 35, a return passage 39 similarly formed by the press-in deforming portion is arranged. The return passage 39 is connected to the pressure passage 35 via the connection hole 41 and extends from the connection hole to almost the end of the pressure passage 35. The pump chamber 23, the pressure passage 35 and the return passage 39 are closed on the opposite side of the casing 1 by a first casing cover 43 tightly screwed onto the end face 21 of the pump casing 1. The casing cover 43 has a pressure hole 45 extending from the pressure passage 39 and a return hole 4 extending from the return passage 39.
7 are arranged. In this case, the casing cover 43
It is itself flanged to the cylinder head of the internal combustion engine to be supplied with fuel such that the pressure hole 45 and the return hole 47 open directly into the corresponding fuel passage in the cylinder head. In order to seal the pump chamber 23 of the gear pump 3 against the internal combustion engine and the vane pump 5, two shaft seal rings 49 are arranged on the drive shaft 15 in addition to the various seal rings in the casing cover. The shaft seal ring 49 connects the pump chamber 23 to the drive shaft 1.
Close at 5. The vane pump 5 shown in detail in FIGS. 1 and 4 has a cylindrical rotor 51 arranged in the pump chamber 7. The rotor 51 has an axial hole and is guided by a cylindrical inner wall surface 53 on the peripheral surface of a cylindrical casing web 11 in the form of a sliding bearing. The rotor 51 is provided with a clutch disk 5 press-fitted to the end of the drive shaft 15 opposite to the gear pump 3.
5, it is coupled to the drive shaft 15 by a shape constraint. The clutch disk 55 is connected to the vane pump 5 on the other side.
Is supported by a second casing cover 56 that closes the pump chamber 7. This casing cover 56 is screwed tightly to the end face 9 of the pump casing 1. The cylindrical outer wall 57 of the rotor 51, which restricts the pump chamber 7 radially inward, is advantageously provided with three slits 59 for slidably receiving the vanes 61. These slits 59 are inclined from the radial surface of the rotor 51 in the rotation direction of the rotor 51. The rotor 51 has a part of its outer wall surface 5
The slit 59 is eccentrically arranged in the pump chamber 7 so as to contact the pump chamber wall 63 in the radial direction of the pump chamber 7 at 7. When the end of the vane in the rotor 51 is pressure-loaded by the lubricant, the vane 61 is pushed radially outward during the suction phase and thus the vane 61 in the casing 1 In order to improve the press-fitting force and the sealing action of the vane 61 particularly at a low rotation speed, a sealing surface for the vane 61 is formed. The upper area of the pump chamber 7 forms a suction area 65 of the vane pump 5 when the rotor 51 rotates counterclockwise (FIG. 4). A connection hole 67 is opened in the suction area 65, and a connection pipe piece 69 is inserted into the connection hole 67, and a hose from an automobile brake force booster is placed on the connection pipe piece 69. The conduit is insertable. In this case, a check valve 71 that opens toward the pump chamber 7 is provided in the hole 67 on the upstream side of the connecting pipe piece 69 so that a negative pressure can be generated as effectively as possible in the brake force booster. Have been. The outlet of the pressure from the vane pump 5 is carried out by means of an outlet hole 73 which extends from the minimum cross-sectional area of the pump chamber 7 of the vane pump 5 and, on the outlet side, is connected to a flange in the cylinder head connected to the lubricant circuit of the internal combustion engine. Done.

The lubrication of the vane pump 5 is effected via obliquely arranged lubricant holes 75, shown in detail in FIG. The lubricant hole 75 is provided in the first casing cover 43.
Is connected to the lubricant circuit of the internal combustion engine through a suitable hole 77 at the end of the rotor 51 and opens into the pump chamber 7 at the level of the end face of the rotor 51. In this case, in order to guide the lubricant (oil) first, the rotor 51 has a ring groove 79 on the end face.
And a press-deformable portion on the inner wall surface 53 and a selectively coaxial through-hole 81. Through these, the lubricant reaches the pump chamber 7, from which the lubricant returns to the lubrication circuit of the internal combustion engine via the outlet hole 73. In this case, the through hole 81 penetrates the rotor 51 in the present embodiment in the axial direction.
1 is formed by a guide slit 59 for receiving the same.
Further, in order to lubricate the drive shaft 15, a pushing deformation portion is provided on the wall of the through hole 13.

In order to limit the pressure of the fuel transferred from the gear transfer pump 3, a pressure limiting valve 83 is connected to the pressure passage 35.
And the return passage 39 are disposed in the connection hole 41.
The pressure limiting valve 83, shown in detail in FIG. 5, is connected to a return conduit 85 to a storage tank of the internal combustion engine and has a valve member 87 between the opening of the pressure passage 35 and the return passage 39. I have. The valve member 87 is kept in contact with a valve seat 91 formed by a hole step by a valve spring 89. In this case, the valve spring 89 is supported on the other hand by a clamping sleeve 93. Via the position of this tightening sleeve 93 in the connection hole 41, the bias of the valve spring 89 and thus the pressure limiting valve 83
The opening pressure of is adjustable. This pressure limiting valve 83 can also be used as a pressure regulating valve that continuously limits the maximum volume through a proportionally generated counter pressure.

The transport device of the present invention works in the following manner.

During operation of the internal combustion engine, the camshaft of the internal combustion engine drives the drive shaft 15 of the transport device via an elastic coupling device on the entraining disk 17. This rotational movement of the drive shaft 15 is transmitted to the gear 25 of the gear transfer pump 3. The gear 25 itself drives a second gear that meshes with the gear 25. In this case, in a known manner, fuel is sucked from the storage tank into the suction chamber 29 of the gear pump 3 via the suction hole 33. In this case, since the gear pump 3 is also in a state where it can also suck in and convey air, the gear pump can self-evacuate if the fuel line is emptied. The fuel is then conveyed to the pressure chamber 31 between the meshing end faces of the gear. From this pressure chamber 31 the fuel flows via the pressure passage 35 to the pressure holes 45 and further towards the internal combustion engine or a high-pressure injection pump provided in the internal combustion engine.

The pressure of the conveyed fuel is limited by using a pressure limiting valve 83 disposed in the connection hole 41. Since the pressure limiting valve 83 opens from a predetermined pressure in the pressure passage 35, fuel can flow to the return conduit 85.
This return conduit 85 also serves to return fuel not needed in the internal combustion engine. For this purpose, the return line of the internal combustion engine opens into the return line 39 of the conveying device, which is connected via a connection hole 41 to a return line 85 to the tank at all times. The rotor 51 of the vane pump 5 that is rotationally driven through the clutch disc 55 sucks air from the brake booster through the connecting pipe piece 69 while rotating in the pump chamber 7. For this purpose, the volume of the individual chambers limited by the vanes 61 is increased during the rotational movement of the rotor 51, starting from the opening of the connection hole 67, so that a negative pressure is generated in a known manner. . As the rotational movement progresses, the volume of each chamber decreases after each chamber moves out of the area that matches the connection hole 67, so that the trapped air flows with the lubricant flowing through the pump chamber 7, The mixture is conveyed under pressure to the outlet 73, from which the mixture is again fed to the lubricant circuit of the internal combustion engine. In this case, the check valve 71
Prevents air from returning to the brake booster, especially after the internal combustion engine has been shut down. Thus, depending on the transport device according to the invention, the device for transporting the fuel and the device for generating the negative pressure, which were conventionally separated, are arranged in a simple manner in a common housing and both devices Can be driven by a common drive shaft. As a result,
Manufacturing costs and the required construction space are significantly reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a transfer device according to the present invention.

FIG. 2 is a side view of one side of the transfer device of FIG. 1;

FIG. 3 is another side view of the transfer device shown in FIG.

FIG. 4 is a side view, corresponding to FIG. 2, showing the components of the vane pump.

FIG. 5 is a partial view of FIG. 4, showing a pressure limiting valve located between the return passage and the pressure passage;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump casing 3 Gear pump 5 Vane pump 7 Pump chamber 9 End face 11 Casing web 13 Through hole 15 Drive shaft 17 Carrying disk 19 Fitting key 21 End face 23 Pump chamber 25 Gear 27 Pin 29 Suction chamber 31 Pressure chamber 33 Suction hole 35 Pressure Passage 37 Web 39 Return passage 41 Connection hole 43 Casing cover 45 Pressure hole 47 Return hole 49 Shaft seal ring 51 Rotor 53 Inner wall surface 55 Clutch disk 56 Casing cover 57 Outer wall surface 59 Slit 61 Vane 63 Pump chamber wall 65 Suction range 67 Connection Hole 69 Connecting pipe piece 71 Check valve 73 Outlet hole 75 Lubricant hole 77 Hole 79 Ring groove 81 Through hole 83 Pressure limiting valve 85 Return conduit 87 Valve member 89 Valve spring 91 Valve seat 93 Tightening sleeve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hanspeter Meyer Hallein Wiesengasse, Austria 1

Claims (18)

[Claims] 1. A device for transporting fuel from a storage tank to an internal combustion engine of a motor vehicle, comprising a transport pump (3), in particular a gear pump, connected in a transport conduit from the storage tank to the internal combustion engine. The transfer pump (3) has at least one pump chamber (23) in a pump casing (1) and includes a rotating displacement member, the displacement member storing a fuel in a storage tank. A suction chamber (29) that can be connected to the internal combustion engine to a pressure chamber (31) that can be connected at least indirectly to the internal combustion engine, wherein the transfer pump (3) conveys air to the pumps (5) and (1). The suction side (65) of the pump (5) is connected to a brake booster of the motor vehicle to generate a negative pressure, and the pump (5) communicates with the transport pump (3) and air. The port to be transported Pump (5) is coaxially
Arranged in two common casings (1), rotationally driven by a common drive shaft (15) and arranged in a common casing (1) of the transport pump (3),
The pump for conveying air is configured as a vane pump (5), has a rotor (51) supported in a casing (1) and driven to rotate, and receives a large number of vanes (61) on the rotor (51). The vane (61) is provided with a guide slit (59), and an end of the vane (61) facing outward in the axial direction is provided with a pump chamber (7) of a vane pump (5) eccentrically arranged with respect to the rotor shaft. A) for transporting fuel from a storage tank to an internal combustion engine of a motor vehicle, characterized in that it slides tightly along the wall of (a). 2. The transfer pump configured as a gear transfer pump (3) and the vane pump (5) are arranged one behind the other in the axial direction, and the driven gear (25) of the transfer pump (3) is arranged. ) And the rotor (5) of the vane pump (5).
And 1) are rotationally driven by a common drive shaft (15).
The device according to claim 1. 3. The device according to claim 2, wherein the common drive shaft is connected to the axial end of a camshaft of the internal combustion engine via a resilient connection. 4. The resilient connecting member comprises at least one fitting key (19) made of a resilient material, the fitting key (19) comprising an end face of a camshaft and a drive shaft (15).
4. The device as claimed in claim 3, wherein the device protrudes into a groove provided in the end face of the entraining disc (17) press-fitted thereon. 5. A clutch disc (55) is press-fitted on the drive shaft (15) on the side opposite to the connecting member (17, 19) to the camshaft, and the clutch disc (55) is connected to the vane pump (55). 5. Apparatus according to claim 4, wherein the apparatus is connected to the rotor (5) of (5) by shape constraints. 6. A cylindrical casing web (11) is provided in a pump casing (1), and a rotor (51) of a vane pump (5) is slidably guided on a peripheral surface of the casing web (11). The casing web (11) has a through-hole (13) disposed coaxially with the rotor (51), and the drive shaft (1) is provided in the through-hole (13).
3. The device according to claim 2, wherein 5) is slidably guided. 7. The vane pump according to claim 1, wherein the vanes are movable in a radial direction of the rotor in a direction of rotation of the rotor from a radial plane of the rotor.
The described device. 8. A connecting hole (67) for receiving a connecting pipe piece (69) for connecting a hose to a braking force booster is opened in the pump chamber (7) of the vane pump (5). 2. The device according to claim 1, wherein a non-return valve (71) which opens towards the pump chamber (7) is connected upstream of the tube piece (69). 9. A lubrication hole (7) provided obliquely in the pump casing (1) and connected to a lubricant circuit of the internal combustion engine.
5) is open on the end face of the rotor (51) on the side facing the cam shaft, and a ring groove (79) is arranged on the end face of the rotor (51) in the opening area.
From 9), the indented deformation portion on the inner wall surface (53) in the radial direction and / or the coaxial through-hole (81) in the rotor lead to the end surface (9) of the pump casing (1) on the opposite side to the cam shaft, From this extends a lubricant outlet opening (73) connected to the lubricant circuit of the internal combustion engine,
The device according to claim 1. 10. The device according to claim 2, wherein the driven gear (25) of the gear transport pump (3) is coupled to the drive shaft (15) with a shape constraint. 11. A pump casing (1) comprising a return passage (39) connected to a return conduit of an internal combustion engine and a pressure passage (35) extending from a pressure chamber (31) of a pump chamber (23) of a gear pump (3). In one of the casing end faces (2
3. The device according to claim 2, wherein the device is configured as the indentation deformation part of 1). 12. The pump casing (1) includes a drive shaft (1).
End faces (21, 9) arranged perpendicular to the axis of 5)
, The first casing cover (43) closing the pump casing (1) on the side facing the camshaft comprises a pump chamber (23) and a return of the gear transport pump (3). And a second casing cover (56) closing the pressure passage and closing the pump casing (1) on the side opposite to the camshaft.
Closing the pump chamber (7) of the vane pump (5). 13. The device according to claim 5, wherein the clutch disc (55) is in contact with the second casing cover (56). 14. A return hole (4) for opening the return passage (39) from the internal combustion engine to the first casing cover (43).
7) and a pressure hole (45) opening to the pressure passage (35), and these holes are provided in the first casing cover (4).
13. The device according to claim 11, wherein the connecting holes in the cylinder head of the internal combustion engine make intimate contact at the end face of 3) opposite the pump casing. 15. A connecting passage (41) between the return conduit (39) and the pressure passage (35), which is connected to the return conduit (85) to the storage tank, is arranged in the pump casing (1), A pressure passage (35) and a return conduit (8) are provided in the connection passage.
15. The device according to claim 14, wherein a pressure limiting valve (83) for opening and closing the connection to the return passage (39), which is always connected to 5), is connected. 16. The pump chamber (2) of the gear transfer pump (3).
13. The device according to claim 12, wherein 3) is sealed to the vane pump (5) and the internal combustion engine by two shaft seal rings (49) arranged on the drive shaft (15). 17. A pump chamber (23) of a transfer pump (3).
3. The device as claimed in claim 2, wherein the fuel supply conduit (33) which is open to the throttle is provided with a throttle. 18. A shaft seal ring (49) for separating a medium, a fuel and a lubricant is provided with a pump chamber (23) of a transfer pump (3) by a groove so that a pressure difference is generated toward the pump chamber (23). 17. The device of claim 16, wherein the device is coupled.