EP3172427A1

EP3172427A1 - High-pressure connection device

Info

Publication number: EP3172427A1
Application number: EP15735923.3A
Authority: EP
Inventors: Gerhard Weiss; Juergen Simmerer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-07-21
Filing date: 2015-07-06
Publication date: 2017-05-31
Also published as: CN106536915A; DE102014214110A1; WO2016012224A1; CN106536915B

Abstract

The invention relates to a high-pressure connection device with a housing (1), in which there is arranged a receiving opening (2) into which a duct (3) extending in the housing (1) opens, and with a pressure pipe stub (9), in which there is formed a high-pressure duct (11) which opens at one end into an end side (13) of the pressure pipe stub (9), and with an external thread (10) which is formed on the pressure pipe stub (9) and engages in an internal thread (5) formed in the receiving opening (2) with the formation of a screw connection, with the result that, when screwing the pressure pipe stub (9) into the receiving opening (2), said stub comes to bear against a seat surface (4) of the receiving opening (2) by way of a sealing surface (15) formed on the end side (13). According to the invention, a high-pressure connection device is specified which, combined with a simple structure, has an increased releasing moment by comparison with the prior art. This is achieved in that at least one flank of the screw connection has two flank angles β, γ which are different from one another.

Description

description

title

The invention relates to a high-pressure connection device with a housing in which a receiving opening is arranged, into which a channel extending in the housing opens, and with a pressure pipe socket, in which a

High-pressure channel is formed, which opens at one end into an end face of the pressure pipe nozzle, and with a pressure on the pressure pipe socket

trained external thread, which formed in a receiving opening in the

Internal thread engages to form a screw, so that the

Pressure pipe socket comes when screwing into the receiving opening with a formed on the end face sealing surface on a seat surface of the receiving opening to the plant.

State of the art

Such a high-pressure connection device is known from DE 101 25 439 AI. This high-pressure connection device is arranged on an injector body of a fuel injection system for an internal combustion engine and further has a pressure pipe socket which can be screwed to the injector body. A high-pressure line can in turn be screwed to the pressure pipe socket. In this case, the internal thread of the injector and the external thread of the pressure pipe socket is formed with a Sägezahngewinde. In addition, an engaging in the screw thread formed by the internal thread and the external thread locking pin is provided, which ensures that the

Pressure pipe socket is blocked in a rotational movement relative to the injector body. The invention has for its object to provide a high-pressure connection device, which has a relation to the prior art increased release torque in a simple structure.

Disclosure of the invention

This object is achieved in that at least one edge of the

Screwing two mutually different flank angle ß, γ has. It has been found that in a screw connection in which at least one flank has two or more mutually different flank angles β, γ, the release torque is significantly increased compared to a screw connection whose flanks are designed, for example, as symmetrical 60 ° flanks. This makes it possible, for example, to dispense with the use of an adhesive which is added during the screwing of the pressure pipe socket into the receiving opening in the screw to increase the release torque. Indeed, in the practice of screwing using an adhesive, it has been found that the amount of adhesive actually present in the thread depends on a number of factors which are inaccessible to control. These are: the viscosity of the adhesive or the adhesive charge, which in turn is temperature-dependent and may also be influenced by external conditions during storage and transport of the adhesive charge, the wetting of the threads of the screw, the

Surface texture of the adhesive parts to be wetted threaded parts, possibly also on the surface residues, traces or remnants of media of all kinds, such as oils, greases, coolants, lubricants, detergents or preservatives, other properties of the adhesive charge, such as

Surface tensions, storage time, aging and other properties. These not fully controllable influencing factors can in

Manufacturing process or assembly process cause either too little adhesive or too much adhesive is applied to the thread. In particular, cases occur in which too little or too much adhesive is applied to all threads of the thread.

Too little adhesive has the consequence that the screw is not reinforced in a planned manner, and the release torque of this screw is inadmissible low. Another possible consequence is a leaky one

Screw connection through which the medium under high pressure can escape. This case is particularly critical because such a too low release torque can not be tested without loosening the screw connection after curing of the adhesive and thus destroy it. Too much glue has the consequence that not all the glue in the

Gaps of the screwing takes place and a part of the adhesive emerges at the end of the screw connection. This inadmissibly escaping adhesive must be removed consuming or inside the channel or the

High-pressure channel and in the worst case lead to blockages.

The use of a further described in the prior art

Locking pin is only constructive and expensive to apply manufacturing technology. The fitting according to the invention, on the other hand, can be dismantled non-destructively, i. the pressure pipe socket can with the application of an increased release torque - otherwise but without adverse consequences - from the receiving opening

be unscrewed. With the fitting according to the invention a multiple Wiederverschraubbarkeit the pressure pipe connection with the housing is possible. The result is a saving of costs, components and costs

Material reached.

In a development of the invention, the flank has two partial flanks which enclose an angle γ <180 °. Such an angle γ <180 ° has proven to be particularly advantageous. In a further embodiment of the invention, the flank is arranged with two flank angles ß, γ on the internal thread of the housing. This arrangement has the advantage that the flank with the two flank angles ß, γ can be easily manufactured during the manufacture of the housing, which is manufactured according to individual specifications, while an existing series part can be used for the pressure pipe socket to be screwed.

In a further embodiment of the invention, the flank with the two

Flank angles ß, γ the ground facing away from the seat outer edge. Just this configuration increases the release torque in the desired manner.

In a further embodiment of the invention, the flank angle ß (the

Outside edge) in a range between 30 ° and 80 °, preferably between 40 ° and 70 °, more preferably between 45 ° and 65 °.

Again, in another embodiment, the flank angle γ (the outer edge) is in a range between 130 ° and 170 °, preferably between 135 ° and 165 °, more preferably between 145 ° and 155 °. On the one hand, this embodiment has proven to be easily manufacturable, but on the other hand, this embodiment ensures the desired increase in the release torque.

In a development of the invention, a flank angle α of the inner flank opposite the outer flank lies in a range between 30 ° and 80 °, preferably between 40 ° and 70 °, particularly preferably between 45 ° and 65 °.

This embodiment has been found in the context of the invention to be particularly advantageous.

At the same time, the aspect ratio of the lengths of the through

Flank angle γ formed partial flanks x to y between% and 4, preferably between 14 and 2, particularly preferably (1: 2) +/- 0.2.

In a further development of the invention, the housing is an injector body. Although the subject invention of any

High pressure connection device can be realized, is the preferred Application to an injector body of an injection system

Internal combustion engine given. The injector body has the specified

Receiving opening, with which the pressure pipe socket is screwed. The pressure pipe socket has, opposite to the threaded flange bolted to the injector body, a second threaded flange onto which a screw connection of a high-pressure line is screwed. When loosening this screw connection must be ensured that the pressure pipe socket is not unscrewed from the receiving opening of the injector body. This is achieved reliably by the embodiment according to the invention, in that the release torque with respect to the screw connection with the high-pressure line is approximately doubled by this.

Further advantageous embodiments of the invention are the

Drawing description can be found in which an illustrated in the figures embodiment of the invention is described in detail.

Show it:

FIG. 1 shows a longitudinal section through a high-pressure connection device,

Figure 2 is a detail enlargement II of Figure 1 and

Figure 3 is a detail view of the invention formed

Screwing.

Figure 1 shows an embodiment of an inventive

High-pressure connection device. A housing 1 designed as an injector body has a receiving opening 2 into which a high-pressure passage 3 extending in the housing 1 opens. The housing 1 is preferably an injector body as part of a fuel injection system for internal combustion engines, wherein the injector body is used to inject fuel into an associated combustion chamber of the internal combustion engine. The receiving opening 2 is cylindrical, wherein the base of the receiving opening 2 is formed as a seat surface 4. The high-pressure passage 3 in the housing 1 in this case opens centrally into the seat surface 4, so that it has an annular disk-shaped form. At the Outer surface of the receiving opening 2 is an internal thread 5 is formed, which has a facing the seat surface 4 inner edge 6 and a direction away from the seat surface 4 outer edge 7 (see Figure 2 and 3). The outer flank 7 has two partial flanks 8a, 8b (see FIG. 3), which are two to one another

have different flank angles ß, γ. This embodiment will be described in detail below.

In the receiving opening 2, a pressure pipe socket 9 is screwed, which at its end facing the receiving opening 2 at least

is approximately cylindrical, and in this area has an external thread 10 which engages in the internal thread 5 of the receiving opening 2. The external thread 10 is as conventional thread with

formed, for example, two symmetrical 60 ° flanks. Of the

Pressure pipe socket 9 has a continuous high-pressure channel 11, which is located in an end region of the pressure pipe socket 9

High-pressure connection 12 with the housing 1 facing end face 13 of the pressure pipe connecting piece 9 connects. The high pressure port 12 is included

for example, via a high pressure line with a

High-pressure fuel storage or a high-pressure fuel source connected.

FIG. 2 shows an enlarged detail II of the end region of the pressure pipe connecting piece 9 facing the housing 1

Druckrohrstutzens 9 is a circumferential annular web 14 is formed, the

Mouth of the high-pressure passage 11 surrounds the end face 13. At the annular web 14, a sealing surface 15 is formed, which comes with screwed pressure pipe socket 9 on the seat surface 4 of the receiving opening 2 to the plant. By the

Screwing the pressure pipe socket 9, the sealing surface 15 presses into the seat surface 4, so that the high-pressure channel 11 is sealingly connected to the channel 3.

Figure 3 shows a detailed view of the fitting according to the invention with a distribution of the total axial forces on the individual turns in the case of five turns, the individual turns between 17% (left) and 24% (right) absorb the axial forces. This narrow distribution or the small difference between the minimum value and maximum value has the consequence that the fitting according to the invention can be designed to the load limits and can absorb more axial forces, as a screw connection of the same dimensions corresponding to the prior art. In the right diagram of force

(24%) the force vectors are shown schematically. The short vector F _RA D-60 ° describes the forces in the radial direction (acting upwards in the drawing), which is capable of accommodating a screw connection with two symmetrical 60 ° flanks (corresponding to the lower hatched thread in FIG. 3).

The long vector F _RA D-3O _° describes the forces in the radial direction (acting upwards in the drawing), which is able to receive the screw connection according to the invention with a second flank angle. Assuming equal axial forces F _A xi-3o ° and F _A xi-6o °, the following applies:

The different radial forces F _RAD . ₆ o _° and F _RAD - _{30 °} cause different normal forces F _N. ₆ o ° and F _N - _{30 °} . This has the consequence that the amount, that is, the length of the vector in the inventive 30 ° case is almost twice as large as the amount of the vector F _N. ₆ °. Differences of amounts of vectors F _N. ₆ o ° and F _N - _{30 °} represent the difference between the normal forces which the respective screwing is capable of applying. To release the respective screw solenoids are each required to overcome the prevailing forces in the normal direction. Thus, summarized to solve an inventively designed screw almost twice as high

Loosening torque required as in the presence of a prior art fitting with two symmetrical 60 ° flanks.

The detail enlargement according to FIG. 3 shows the external thread 10 of the pressure pipe connecting piece 9 having the symmetrical 60 ° flanks

Inner edge 6 of the external thread 10 also has an edge with a particularly preferred angle α of 60 ° +/- 5 °. The opposite outer flank 7 of the internal thread 5 is subdivided into the two partial surfaces 8a, 8b whose dimension ratio is particularly preferably between (1: 2) +/- 0.2. The partial surfaces 8a, 8b include the angle γ, which is particularly preferably 150 ° +/- 5 °, while the angle ß of the partial surface 8a has an angle ß of particularly preferably 60 ° +/- 5 °.

The two partial edges 8a, 8b with the different angle impact can each - as shown - on the internal thread 5 or also on the

External thread 10 to be executed. Preferably, the two partial edges 8a, 8b are arranged on the most heavily loaded flanks in the screwed state. Consequently, in an unillustrated embodiment according to FIG. 3, lower part, the upper thread (without hatching) can be designed as a pressure pipe thread (bolt thread) and the lower thread (with hatching) as an inner thread (nut thread). In a further embodiment according to FIG. 3 lower part, the upper thread (without hatching) can be formed as an internal thread (female thread) and the lower thread (with hatching) as a pressure pipe thread (bolt thread).

Claims

claims

1. High-pressure connection device with a housing (1) in which a

Receiving opening (2) is arranged, in which a in the housing (1) extending channel (3) opens, and with a pressure pipe socket (9) in which a high-pressure channel (11) is formed, which at one end in a

End face (13) of the pressure pipe nozzle (9) opens, and with an on the pressure pipe socket (9) formed external thread (10) which engages in an opening formed in the receiving opening (2) internal thread (5) to form a screw, so that the pressure pipe socket (9) at

Screwing into the receiving opening (2) with a on the end face (13) formed sealing surface (15) on a seat surface (4) of the receiving opening (2) comes to rest,

characterized in that at least one flank of the screw has two mutually different flank angle ß, γ.

2. High-pressure connection device according to claim 1,

characterized in that the flank has two partial flanks (8a, 8b) which enclose an angle γ <180 °.

3. High-pressure connection device according to claim 1 or 2,

characterized in that the flank is arranged with two flank angles ß, γ on the internal thread (5).

4. High-pressure connection device according to claim 1 or 2,

characterized in that the flank is arranged with two flank angles ß, γ on the external thread (10).

5. High-pressure connection device according to claim 3 or 4,

characterized in that the flank is of the seat surface (4) pioneering outer edge (7).

6. High-pressure connection device according to one of the preceding claims, characterized in that the flank angle ß in a range between 30 ° and 80 °, preferably between 40 ° and 70 °, more preferably between 45 ° and 65 °.

7. High-pressure connection device according to one of the preceding claims, characterized in that the flank angle γ in a range between 130 ° and 170 °, preferably between 135 ° and 165 °, more preferably between 145 ° and 155 °.

8. High-pressure connection device according to one of the preceding claims, characterized in that the flank angle α of the outer flank (7) opposite inner edge (6) in a range between 30 ° and 80 °, preferably between 40 ° and 70 °, more preferably between 45 ° and 65 °.

9. High-pressure connection device according to one of the preceding claims, characterized in that the housing (1) is an injector body.