Fuel distributor

Abstract

A fuel distributor features a pressure accumulator 2 with a longitudinal hollow space 3 to receive pressurized fuel. The pressure accumulator 2 possesses at least one threaded socket 7 which connects with the longitudinal hollow space 3 and which features interior threading 8, and into which a threading cap 11 with exterior threading 13 is inserted. The threading socket 7 features a sealing surface 16, which ends up being pressed onto a sealing seat 18 set up inside the pressure accumulator 2. According to the invention, a leakage channel 27 is formed within the threading cap 11. The configuration of the fuel distributor according to the invention with the leakage channel 27 in the threading socket 7 allows leakage testing under high pressure to be carried out during a short cycle or detection times, and with a high degree of precision.

Claims

1. A fuel distributor, which features a pressure accumulator with a longitudinal hollow space to receive pressurized fuel, where the pressure accumulator possesses at least one threading socket featuring interior threading connected to the longitudinal hollow space, and where a threading cap is inserted into the threading socket, which itself features external threading, where the threading cap features a sealing surface, which ends up being pressed onto a sealing seat set up in the pressure accumulator, wherein the threading cap has a leakage channel formed by a cross bore in a cylindrical section which is connected to a recess.

2. The fuel distributor according to claim 1, wherein the threading cap has the cylindrical section with a conical end section, on which the sealing surface is formed.

3. The fuel distributor according to claim 1, wherein the threading cap has a recess with an interior polyhedral surface.

4. The fuel distributor according to claim 1, wherein the leakage channel is formed by an exposed space provided on the exterior circumference of the cylindrical section and an interior circumference section of the pressure reservoir.

5. The fuel distributor according to claim 1, wherein the threading socket is a single-piece component of the pressure accumulator and being made of a uniform single material.

6. The fuel distributor according to claim 1, wherein the threading cap is cold-flow pressed.

7. The fuel distributor according to claim 1, wherein the sealing seat is formed in a sealing cone of the pressure accumulator.

8. The fuel distributor according to claim 1, wherein the threading socket is formed on an opening-side end of the pressure accumulator.

9. The fuel distributor according to claim 1, wherein the threading socket is configured to receive a sensor.

Description

DESCRIPTION OF THE DRAWINGS

(1) The invention is described in the following sections based on design examples in greater detail. In the figures:

(2) FIG. 1 shows a threading cap according to the invention, in a rear view perspective;

(3) FIG. 2 shows the threading cap according to the illustration from FIG. 1 in a perspective view from the side of the sealing seat;

(4) FIG. 3 shows the threading cap from a frontal view toward the centrally situated recess;

(5) FIG. 4 shows a frontal view of a second design form for a threading cap;

(6) FIG. 5 shows a longitudinal cross section view of the threading cap as per the illustration in FIG. 4 along line A-A;

(7) FIG. 6 shows a frontal view toward the opening-side end of a pressure accumulator;

(8) FIG. 7 shows a longitudinal cross-section view through the pressure accumulator as per FIG. 6, along line B-B;

(9) FIG. 8 shows an enlarged illustration of cutaway section C in FIG. 7;

(10) FIG. 9 shows the threading cap according to the illustration in FIG. 8 from a perspective view;

(11) FIG. 10 shows the opening-side of a pressure accumulator with an integrated pressure sensor, and

(12) FIG. 11 shows a cutaway view of the pressure sensor as per the illustration in FIG. 9 in a perspective view toward the threading cap of the pressure sensor.

(13) Mutually correlating parts or components of parts are marked in the figures with identical reference numbers.

DETAILED DESCRIPTION OF THE INVENTION

(14) FIG. 7 shows a fuel distributor 1. The fuel distributor 1 is part of the reservoir injection system of a combustion engine. The pressure generation and fuel injection functions are mutually disconnected in such reservoir injection systems. A separate high-pressure pump generates continuous pressure. This pressure, which is accumulated independently from the injection sequence, is available on a permanent basis in the fuel distributor 1.

(15) The fuel distributor 1 features a pipe-shaped pressure accumulator 2 with a longitudinal hollow space 3 as well as a fuel inlet on the side of the pump, not shown here, and also multiple injector connections 4. The statically compressed fuel is stored in the longitudinal hollow space 3 of the pressure accumulator 2 and made available to the injectors of a cylinder bank via the injector connections 4 on a distributed basis. In order to firmly anchor the fuel distributor 1 onto a combustion engine, mounting brackets 5 are provided.

(16) The opening-side end 6 of the pressure accumulator 2 is configured as a threaded socket 7 and features interior threading 8. The threading socket 7 is in contact with the longitudinal hollow space 3 of the pressure accumulator 2.

(17) In order to seal off the end 6 in a leak-tight fashion, a threading cap 9, 10, 11 is screwed into the threading socket 7.

(18) An initial design form of a threading cap 9 is illustrated in FIGS. 1 through 3.

(19) FIGS. 4 and 5 show a second design form for a threading cap 10.

(20) The illustrations in FIGS. 6 through 8 show a third design form for a threading cap 11.

(21) Each threading cap 9, 10, 11 features a threading section 12 with an exterior threading 13 oriented toward the interior threading 8 of the threading socket 7. From the threading section 12 toward the inside in the direction of the longitudinal hollow space 3, a cylindrical section 14, which features a conical end section 15, connects to the threading section 12.

(22) A sealing surface 16 is formed on the conical end section 15. A sealing seat 18 is formed in a sealing cone 17 within the pressure accumulator 2. With the sealing surface 16, the threading cap 9, 10, 11 ends up being pressed onto the sealing seat 18 in a leak-tight fashion.

(23) Each threading cap 9, 10, 11 features a centrally situated recess 19 that is externally accessible. In the recess 19, an interior polyhedral area 20 in the shape of an interior hexahedron is formed. The interior polyhedral area 20 serves as a tool attachment point for an outside polyhedral tool. By inserting the tool into the interior polyhedral area 20 and operating the tool, the threading cap 9, 10, 11 is screwed into the threading socket 7. In this fashion, the sealing surface 16 oriented forward in the direction of the longitudinal hollow space 3 ends up being pressed onto the sealing seat 18 in a leak-tight fashion. If required, the threading cap 9, 10, 11 can also be taken out of the threading socket 7 by actuating the tool in the opposite screw turning direction and removed from the pressure accumulator 2.

(24) The threading cap 9 features a leakage channel 21, as can be seen in FIGS. 1 through 3. The leakage channel 21 is formed through axially positioned nuts 22 in the exterior threading 13. The nuts 22 run parallel along the longitudinal axis of the threading cap 9 and cut through the threading channels of the exterior threading 13. The nuts 22 or the leakage channel 21 extend to the front side 23 of the threading cap 9 and create a connection to the outside environment.

(25) The installed threading cap 9 seals off the longitudinal hollow space 3 with its sealing surface 16 pressed on the sealing seat 18. During testing for leak-tightness, the pressure accumulator 2 is filled under pressure with a testing gas. In case of a leak in the area of the sealing seat 18, the testing gas will infiltrate via the leakage channel 21 to the exterior of the threading cap 9 and can presently be detected with suitable testing devices quickly and reliably.

(26) In the case of the threading cap 10 illustrated in FIGS. 4 and 5, a leakage channel 24 is created in the form of a cross boring 25 made into the cylinder section 14. It is connected with the recess 19 in the threading cap 10. For this purpose, the recess 19 is extended by a blind hole bore 26. The cross boring 25 and the blind hole bore 26 intersect, such that exiting testing gas infiltrates via the cross bore 25 and the blindfold bore 26 into the recess 19, from where detection can take place.

(27) In the design example illustrated in FIGS. 6 through 9 a threading cap 11 has been provided which, as described before, ends up being pressed with its sealing surface 16 into the internally situated conical end section 15 in a leak-tight fashion against the sealing seat 18 formed in the sealing cone 17 of the pressure accumulator 2. A leakage channel 27 is formed by an exposed space 29 situated between the external circumference of the cylinder section 14 and an inner circumference section 28 of the pressure reservoir 2. The exposed space 29 is in contact with a cross bore 30 made into the wall of the pressure accumulator 2.

(28) In cases of leakage in the area of the sealing seat 18, testing gas infiltrates via the exposed area 29 and the cross bore 30 to the outside, and can then be detected quickly and reliably.

(29) A fuel distributor 1 is also illustrated in FIGS. 10 and 11. The fuel distributor 1 features a pressure accumulator 2 with a longitudinal hollow space 3 for the purpose of receiving the pressurized fuel. The end 6 of the pressure accumulator 2 illustrated in FIG. 10 is configured as a threading socket 7 and features a threading section with internal threading 8. A sealing seat 18 is formed in a sealing cone 17 within the pressure accumulator 2. A pressure sensor or a sensor connection unit 31 is installed in the interior threading 8 of the threading socket 7. For this purpose the sensor connection unit 31 features a threading cap 32 which is integrated using a single uniform material and as a single component onto a flange 33 of the sensor connection unit 31. The threading cap 32 features a threading section 34 with exterior threading 35. A cylinder section 36 with a conical end section 37 on the threading section 34 connects to the free end. The conical end section 37 is configured as a sealing surface 38.

(30) In order to mount and anchor in place the sensor connection unit 31, it is screwed into the interior threading 8 of the threading socket 7 with the threading cap 32. In this fashion, the conical end section 37 with its sealing surface 38 ends up being pressed into the sealing seat 18 of the sealing cone 17.

(31) The threading cap 32 features a leakage channel 39. The leakage channel 39 is formed by the nuts 40 running axially in the longitudinal direction of the threading cap 32 on the exterior threading 35.

(32) Preferably, three nuts 40 are arranged in a 120 partial circle on the exterior circumference of the threading cap 32 on the exterior threading 35. Gas escaping during a leak detection test will be able to run past the nuts 40 or the leakage channel 39 to the outside, and their presence detected there using a testing device.

REFERENCE NUMBERS

(33) 1Fuel distributor 2Pressure accumulator 3Longitudinal hollow space 4Injector connection 5Mounting brackets 6End of 2 7Threading socket 8Interior threading 9Threading cap 10Threading cap 11Threading cap 12Threading section 13Exterior threading 14Cylinder section 15Conical end section 16Sealing surface 17Sealing cone 18Sealing seat 19Recess 20Interior polyhedral surface 21Leakage channel 22Nut 23Front side of 9 24Leakage channel 25Cross boring 26Blind hole boring 27Leakage channel 28Interior circumference section 29Exposed space 30Cross boring 31Sensor connection unit 32Threading cap 33Flange 34Threading section 35Exterior threading 36Cylinder section 37Conical end section 38Sealing surface 39Leakage channel 40Nuts