EP2298940A1 - Automatic frettage (interference fit) device for high pressure components, particularly for pipelines - Google Patents

Abstract

The device for subjecting a high pressure component such as pipelines (5) with autofrettage pressure, comprises a high pressure generating unit associated to the high pressure component to be subjected for pressurization of the high pressure component with the autofrettage pressure, and a high pressure valve unit associated to the second end of the high pressure component, with a closure body (6) for closing a valve seat (24) to a flush channel formed on the high pressure valve unit during subjecting the high pressure component with the autofrettage pressure. The device for subjecting a high pressure component such as pipelines (5) with autofrettage pressure, comprises a high pressure generating unit associated to the high pressure component to be subjected for pressurization of the high pressure component with the autofrettage pressure, a high pressure valve unit associated to the second end of the high pressure component, with a closure body (6) for closing a valve seat (24) to a flush channel formed on the high pressure valve unit during subjecting the high pressure component with the autofrettage pressure in order to separate the high pressure component, and/or a pressure detection unit for detecting the autofrettage pressure. A high pressure channel is formed in the closure body for connecting the pressure detection unit with the high pressure component. The high pressure valve unit comprises an adapter nozzle for connecting with the second end of the high pressure component that forms an end of the valve seat turned away from the high pressure component for the closure body. The adapter nozzle is relocatably arranged in a valve base body (14) of the high pressure valve unit against a spring power. The valve base body is arranged on a piston rod (22) of a hydraulic cylinder. The first hydraulic cylinder is arranged for displacing the closure body in the valve base body of the high pressure valve unit and the second hydraulic cylinder is arranged for pressing the adapter nozzle against the second end of the high pressure component. The closure body is formed as high pressure tube or is connected with the high pressure tube. The closure body is formed through the adapter nozzle for connecting the high pressure valve unit with the second end of the high pressure component. The adapter nozzle is surrounded by the rinsing sleeve relocatably arranged against a spring force for connecting with an external edge of the second end of the high pressure component. Between the rinsing sleeve and the adapter nozzle, a column connected with the flushing channel is formed. A guide-controlled hydraulic cylinder is formed with a hollow piston rod on which the valve base body of the high pressure valve unit is arranged. The pressure detection unit is arranged at an end of a pressure connection turned away the high pressure component and formed in the piston rod. The flushing channel is formed as transverse bore in the valve base body of the high pressure valve unit.

Description

The present invention relates to a device for applying high-pressure components, in particular pipelines, with an autofrettage pressure, comprising: a high-pressure generating unit for pressurizing the high-pressure component with the autofrettage pressure assigned to a first end of the high-pressure component to be acted upon, and a high-pressure valve unit associated with a second end of the high-pressure component Shut-off body for closing a valve seat to separate a flushing passage formed at the high-pressure valve unit in the application of the autofrettage pressure from the high-pressure component when the high-pressure component is acted upon, and a pressure detection unit for detecting the autofrettage pressure.

By means of autofrettage devices, high pressure components, e.g. in the form of pipelines, especially in the form of diesel injection lines, for several seconds with high internal pressures (Autofrettagedrücken) typically applied about 1000 to 15000 bar. The application triggers a material conversion, which causes the treated pipes can withstand high internal pressures permanently.

A known autofrettage device 1 will be described below with reference to FIG Fig. 1 described. The autofrettage device 1 has a high-pressure generating unit 2 which, with an adapter nozzle 4, adopts a first end 3a of a high-pressure component to be acted upon in the form of a diesel injection line 5 . A second, opposite end 3b of the diesel injection line 5 is adapted by an adapter nozzle 6 of a high-pressure valve unit 7 . The two pipe ends 3a, 3b provided with a flare are provided with a union nut 9a, 9b and are pressed against a respective counter-holder 10a, 10b during the adaptation.

To act on the diesel injection line 5 with the autofrettage pressure, an essentially cylindrical main body 11 of the high-pressure generating unit 2 is supplied with oil as autofrettage fluid via a transverse bore 12 , which passes into the interior of the diesel injection line 5 and from there into a high-pressure region 13 which is located in a valve main body 14 (valve block ) of the high-pressure valve unit 7 is formed. In the high-pressure region 13 of the high-pressure valve unit 7, a valve ball 15 is provided as a shut-off body, which rests against a high-pressure region 13 formed on the valve main body 14 in the closed valve state and separates the high-pressure region 13 from a flushing bore 16 provided in the valve block 14.

By means of a provided on the high-pressure generating unit 2 high-pressure piston 17 , the autofrettage pressure in the diesel injection line 5 can be generated with a closed flushing bore 16. A pressure sensing unit 19 (high-pressure sensor) communicating with the high-pressure area 13 via a measuring bore 18 extending in the transverse direction serves to detect the autofrettage pressure in order to be able to perform pressure regulation or pressure monitoring.

For the flushing of the autofrettage device 1 after the application of the autofrettage pressure, the pressure applied by the high-pressure piston 17 is reduced and the connection to the flushing bore 16 is released by raising the valve ball 15 attached to an opener pin 20 by means of a pneumatic cylinder 21 . The Öffnerstift 20 with the pneumatic cylinder 21 is here as well as the valve block 14 is provided on a piston rod 22 of a hydraulic cylinder 23 , which serves for pressing the Adaptierdüse 6 against the anvil 10b.

For the flushing operation, the high-pressure generating unit 2 can, via the transverse bore 12, apply a flushing fluid, e.g. Air, are supplied to dissipate the remaining oil in the device 1 via the flushing bore 16 on the high-pressure valve unit 7.

At the in Fig. 1 shown autofrettage device 1, the problem arises that the valve block 14 may not withstand the autofrettage pressure permanently. After a longer period of operation, the valve block 14 may burst from the inside, starting at the point at which the measuring bore 18 opens into the high-pressure region 13. Even attempts to achieve a sufficient reduction of the material stresses by optimizing the geometry at the bore branch were unsuccessful.

Object of the invention

It is the object of the present invention to increase the fatigue strength of an autofrettage device of the type mentioned.

Subject of the invention

This object is achieved in that in the shut-off of the high pressure valve unit, a high-pressure channel for connecting the pressure detection unit is formed with the high-pressure component to be acted upon. By providing a high-pressure passage in the shut-off body, it is possible to provide the pressure detecting unit in the axial extension of a bore provided in the valve block to form the high-pressure area, thereby eliminating branching to a measuring bore and reducing the susceptibility to wear of the high-pressure valve unit.

In one embodiment, the high-pressure valve unit has an adapter nozzle for connection to the second end of the high-pressure component, which forms the valve seat for the shut-off body at its end facing away from the high-pressure component. The valve seat can in this case be designed, in particular, as a conical seat on which a shut-off body, e.g. comes in the form of a pin or needle-shaped high-pressure tube or nozzle when closing the flushing channel to the plant. The high-pressure sensor is hereby typically arranged in the axial extension of the adapter nozzle.

In a further development of this embodiment, the Adaptierdüse is slidably mounted in a valve body or valve block of the high-pressure valve unit against a spring force. In this case, the Adaptierdüse is axially movable, wherein the valve seat between the adapter nozzle and shut-off during rinsing, in which the adapter nozzle is pressed against the end of the high-pressure component, is held open by the spring force, so that the flushing passage with the high-pressure component remains connected. The dynamic pressure occurring when flushing the high-pressure component with the Autofrettagemedium at the flushing hole presses the Adaptierdüse in addition to the spring force in the direction of the second end of the high-pressure component, thereby increasing the sealing effect.

In a further development of the valve body of the high-pressure valve unit is mounted on a piston rod of a path-controlled hydraulic cylinder. The valve body is in this case provided on the high-pressure component end facing the typically hollow-bore piston rod. The hollow-bored piston rod can serve to receive or guide a high-pressure tube, which is screwed into the valve body and serves as a shut-off. A travel control of the hydraulic cylinder e.g. by way of a proportional return path return valve is required in the present embodiment to adjust the position of the piston rod so that when the adapter nozzle is pressed against the end of the high pressure component during purging, the valve seat remains open and closed during autofrettage.

In an alternative development, the device has a first hydraulic cylinder for displacing the shut-off body in a valve main body of the high-pressure valve unit. In this case, the shut-off is displaceable in the valve body, while the valve seat forming Adaptierdüse is firmly anchored in the valve body.

In a further development, a second hydraulic cylinder is provided for pressing the adapter nozzle of the valve body against the second end of the high-pressure component during the rinsing process. By dividing the functions rinsing and autoferret on two hydraulic cylinders, the adaptive force on the adapter and the closing force on the valve seat can be controlled separately by means of pressure control valves, so that a proportional directional valve with

Wegerückführung can be dispensed with.

In one embodiment, the shut-off body is designed as a high-pressure pipe or communicates with a high-pressure pipe in connection, at the end facing away from the high-pressure component, the pressure detection unit is mounted. The high-pressure tube can be screwed into the valve body in an axial extension to the adapter, so that it can be dispensed with the provision of a transverse bore for the arrangement of the pressure detection unit in the valve block. The high-pressure pipe can either itself serve as a shut-off body or with another component, e.g. a rinsing nozzle to be connected as a shut-off.

In an alternative embodiment, the shut-off body is formed by an adapter nozzle for connecting the high-pressure valve unit to the second end of the high-pressure component. The second end of the high-pressure component here serves - as in the embodiments described above - as a seat for fluid-tight adaptation of the adapter. However, in contrast to the embodiments described above, in the present case the adapter nozzle is not pressed against the second end of the high-pressure component during rinsing but only during autofretting, while the adaptation during rinsing is opened in order to release the connection to the rinsing channel, i. the second end of the high pressure component acts as a valve seat for the adapter nozzle. Since the high autofrettage pressure of up to 15000 bar requires high forces in the sealing of the valve, the valve seat is subject to a certain wear over a longer service life of the device. The provision of the valve seat on the high-pressure component is advantageous since the valve seat on the high-pressure component only has to be actuated once to change from rinsing to autofretting.

In a further development of this embodiment, the Adaptierdüse of a rinsing sleeve slidably mounted against a spring force for connection to an outer edge of the second end of the high pressure component, wherein between the rinsing sleeve and the Adaptierdüse a connected to the purge passage gap is formed. If the high-pressure component is designed in the form of a pipeline, this typically has a flange at both ends, which can be adapted by the flushing sleeve, wherein the geometry of the flushing sleeve is adapted or adapted to the geometry of the flange. In this case, the autofrettage fluid can reach the flushing channel through the gap formed between the flushing sleeve and the adaptation nozzle. Due to the high flow velocity of the fluid creates a dynamic pressure, which presses the flushing sleeve in addition to the spring force and thus increases the sealing effect. Autofretting takes place here after adapting or pressing the adapter nozzle against the second end of the high-pressure component, in which the gap is closed and thus the connection to the flushing channel is interrupted.

In a further development of this embodiment, the device has a path-controlled hydraulic cylinder with a piston rod on which a valve main body of the high-pressure valve unit is formed. The piston rod with the valve main body can be moved away by means of a proportional directional control valve with Wegerückführung to first adapt the rinsing sleeve and then the Adaptierdüse at the second end of the high-pressure component or the pipe and so to realize the two valve positions for rinsing and autofrettage.

In a development of this embodiment, the pressure detection unit is arranged on an end remote from the high-pressure component of a pressure port formed in the hollow-drilled piston rod. The pressure port communicates with the adapter nozzle via a pressure screw and is inserted into the hollow-bored piston rod. In In this case, it can be dispensed with the provision of a high-pressure tube as a connection between the adapter and the pressure detection unit.

In the cases described above, the flushing channel is typically formed as a transverse bore in a valve main body of the high-pressure valve unit. The connection of the flushing channel or the transverse bore is separated when the high-pressure component is subjected to the autofrettage pressure from the high-pressure component, so that the flushing channel is not exposed to the autofrettage pressure.

Further advantages of the invention will become apparent from the description and the drawings. Likewise, the features mentioned above and the features listed further can be used individually or in combination in any combination. The embodiments shown and described are not to be understood as exhaustive enumeration, but rather have exemplary character for the description of the invention.

Fig. 1

eine schematische Darstellung einer Vorrichtung zur Autofrettage einer Diesel-Einspritzleitung mit einer Hochdruckerzeugungseinheit und einer Hochdruckventileinheit zur Adaptierung der Leitung,

Fign. 2a,b

schematische Darstellungen einer ersten Ausführungsform einer Hochdruckventileinheit in einer ersten Ventilstellung zum Spülen (Fig. 2a) sowie in einer zweiten Ventilstellung zum Autofrettieren (Fig. 2b),

Fign. 3a,b

schematische Darstellungen analog zu Fign. 2a,b von einer zweiten Ausführungsform einer Hochdruckventileinheit, sowie

Fign. 4a,b

schematische Darstellungen analog zu Fign. 2a,b von einer dritten Ausführungsform einer Hochdruckventileinheit.

Show it:

Fig. 1

a schematic representation of a device for Autofrettage a diesel injection line with a high-pressure generating unit and a high-pressure valve unit for adapting the line,

FIGS. 2a, b

schematic representations of a first embodiment of a high-pressure valve unit in a first valve position for rinsing ( Fig. 2a ) as well as in a second valve position for autofretting ( Fig. 2b )

FIGS. 3a, b

schematic representations analogous to FIGS. 2a, b from a second embodiment of a high pressure valve unit, as well

FIGS. 4a, b

schematic representations analogous to FIGS. 2a, b of a third embodiment of a high pressure valve unit.

FIGS. 2a , b show a high pressure valve unit 7a, which the high pressure valve unit 7 in the Autofrettagevorrichtung 1 of Fig. 1 replaced. The high pressure valve unit 7a is different from that of FIG Fig. 1 initially characterized in that the Adaptierdüse 6 at its end facing away from the pipe 5 forms a conical valve seat 24 .

The Adaptierdüse 6 is also slidably mounted along its longitudinal axis in the valve block 14. A coil spring 25 generates a spring force on the adapter nozzle 6 in the direction of the second end 3b of the pipeline 5. Analogous to in Fig. 1 1, the valve block 14 is provided on a piston rod 22 of a hydraulic cylinder 23. To both the in Fig. 2a shown valve position for rinsing as well as in Fig. 2b To realize shown valve position for autofrettage, the piston rod 23 is controlled by means of a (not shown) proportional directional valve with position feedback.

During the in Fig. 2a shown rinsing is held when pressing the Adaptierdüse 6 against the second end 3b of the pipe 5 of the valve seat 24 between the Adapter 6 and a high-pressure pipe 26 which serves as shut-off, using the coil spring 25, so that the flushing hole 16 with the pipe. 5 remains connected. The ram pressure occurring when flushing the pipe 5 with the Autofrettagemedium at the flushing hole 16 presses the Adapter 6 in addition to the spring force in the direction of the second end 3b of the pipe 5 and thereby increases the sealing effect.

During the in Fig. 2b shown Autofrettagevorgangs the piston rod 22 is shifted so far that the tip of the high-pressure tube 26 closes the conical valve seat 24, so that the flushing bore 16 is separated from the pipe 5 and the Autofrettagedruck can be constructed. In the high-pressure pipe 26, a high-pressure channel 27 is formed in the form of a longitudinal bore, which in the in Fig. 2b shown, closed valve position directly adjoins the adapter nozzle 6 to the high pressure sensor 19, which is arranged at the end remote from the pipe 5 end of the high pressure passage 27, to connect to the pipe 5.

An alternative embodiment of the high-pressure valve unit 7b, in which the function of rinsing and autofrettage is taken over by two independently actuable hydraulic cylinders 23a, 23b , is in FIG FIGS. 3a, b and will be described below.

The first hydraulic cylinder 23a serves to displace the high-pressure pipe 26 mounted in a hollow-drilled piston rod 22a of the first hydraulic cylinder 23a in a valve main body 14. At the top of the high-pressure pipe 26 is followed by a scavenging nozzle 28 , which serves as a shut-off body and in which a high-pressure channel 27 is formed which connects the high-pressure sensor 19 to the pipeline 5 via the immediately adjoining high-pressure pipe 26.

To the adapter nozzle 6 of the valve body 14 in the in Fig. 3a shown flushing operation against the second end 3b of the pipe 5 to press, the valve body 14 is attached to a piston rod 22b of the second hydraulic cylinder 23b. The piston rod 22b of the second hydraulic cylinder 23b encloses the piston rod 22a of the first hydraulic cylinder 23a. For the Autofrettagevorgang the piston rod 22a of the first hydraulic cylinder 23a is moved so far until the flushing nozzle 28 on Valve seat 24 of the adapter nozzle 6 sealingly abuts, as in Fig. 3b is shown.

By splitting the functions of rinsing and autoferreting on two different hydraulic cylinders 23a, 23b, at the in FIGS. 3a, b As shown embodiment, the Adaptierkraft to the adapter 6 and the closing force on the valve seat 24 by means of two pressure control valves are controlled independently.

A third embodiment of the high-pressure valve unit 7c, in which the valve seat 24 is formed for the fitting 6 serving as shut-off at the second end 3b of the pipe 5, is in FIGS. 4a , b shown. The integral in the valve body 14 Adaptierdüse 6 is in this case surrounded by a rinsing sleeve 29 , which in the in Fig. 4a shown rinsing process is pressed against a bead formed on the outer edge 30 of the second end 3b of the pipe 5. The flushing sleeve 29 is displaceable in the valve main body 14 in the longitudinal direction against the spring force of a coil spring 25 and sealed against the valve body 14 by means of a hydraulic seal 31 .

Between the Adaptierdüse 6 and the purging sleeve 29, a gap 32 is formed, which at the in Fig. 4a shown rinsing the Spülbohrung 16 connects to the pipe 5. At the subsequent, in Fig. 4b shown Autofrettage the Adaptierdüse 6 by means of a hydraulic cylinder 23 to which the valve body 14 is mounted, and the valve seat 24 is closed at the second end 3b of the pipe 5. The piston rod 22 with the valve body 14 is hereby moved away by means of a proportional directional valve control with Wegerückführung to first adapt the flushing sleeve 29 and subsequently the Adaptierdüse 6 at the second end 3b of the pipe 5 and so can realize the two valve positions for rinsing and autofrettage.

At the in FIGS. 4a, b In the embodiment of the high-pressure valve unit 7c shown, a pressure port 33 is formed in the hollow piston rod 22 and is connected to the adapter nozzle 6 via a pressure screw 34 . The pressure detection unit 19 is arranged at the end of the pressure connection 33 facing away from the pipeline 5, so that the provision of a high-pressure pipe for connecting the pressure detection unit 19 can be dispensed with in this case. A cable connection 35 extending in the hollow-bored piston rod 22 serves to make contact with the pressure detection unit 19 arranged in the piston rod 22.

At the in FIGS. 4a, b shown embodiment of the high-pressure valve unit 7c, the valve seat 24 in contrast to the in FIGS. 2a, b and FIGS. 3a, b shown embodiments not formed on the adapter nozzle 6, but on the pipe 5 itself, so that no wear of the valve seat can occur during repeated switching between rinsing and autofrettage.

In all the embodiments of the high-pressure valve unit 7a-c shown, it is possible to dispense with a bore branch in the area of the valve main body 14 in which the autofrettage pressure is applied, whereby the fatigue strength of the autofrettage device 1 or the high-pressure valve unit 7 can be increased significantly. It will be understood that the high-pressure valve units 7a-c, possibly suitably modified, can be used not only for autofrettage of pipelines, but also for autofrettage of other high-pressure components, such as e.g. used in diesel injection systems of motor vehicles, in water jet cutting or in the high-pressure pasteurization of foods.

Claims (12)

Device (1) for applying high-pressure components, in particular pipelines (5) with an autofrettage pressure, comprising: a high-pressure generating unit (2), which is assigned to a first end (3a) of the high-pressure component to be acted upon, for pressurizing the high-pressure component with the autofrettage pressure, as well as a high-pressure valve unit (7a-c) associated with a second end (3b) of the high-pressure component, having a shut-off member (26, 28, 6) for closing a valve seat (24), around a flushing passage (16) formed on the high-pressure valve unit (7a-c) to separate the loading of the high pressure component with the autofrettage of the high pressure component, as well as a pressure detection unit (19) for detecting the autofrettage pressure, characterized in that a high-pressure channel (27) for connecting the pressure detection unit (19) to the high-pressure component is formed in the shut-off body (26, 28, 6). Device according to claim 1, characterized in that the high-pressure valve unit (7a, 7b) has an adapter nozzle (6) for connection to the second end (3b) of the high-pressure component, the valve seat (24) for the shut-off body (24) facing away from the high-pressure component. 26, 28) forms. Apparatus according to claim 2, characterized in that the Adaptierdüse (6) is slidably mounted in a valve body (14) of the high-pressure valve unit (7a) against a spring force. Apparatus according to claim 3, characterized in that the valve body (14) on a piston rod (22) of a path-controlled hydraulic cylinder (23) is mounted. Apparatus according to claim 2, characterized by a first hydraulic cylinder (23a) for displacing the shut-off body (28) in a valve main body (14) of the high-pressure valve unit (7b). Apparatus according to claim 5, characterized by a second hydraulic cylinder (23b) for pressing the adapter nozzle (6) against the second end of the high-pressure component. Device according to one of the preceding claims, characterized in that the shut-off body is designed as a high-pressure pipe (26) or connected to a high-pressure pipe (26), at its end facing away from the high-pressure component, the pressure detection unit (19) is mounted. Device according to claim 1, characterized in that the shut-off body is formed by an adapter nozzle (6) for connecting the high-pressure valve unit (7c) to the second end (3b) of the high-pressure component. Device according to claim 8, characterized in that the adapter nozzle (6) is surrounded by a rinsing sleeve (29) displaceably mounted against a spring force for connection to an outer edge (30) of the second end of the high-pressure component, wherein between the rinsing sleeve (29) and the Adaptierdüse (6) with the flushing channel (16) connected gap (32) is formed. Apparatus according to claim 9, characterized by a path- controlled hydraulic cylinder (23) with a hollow piston rod (22) on which a valve body (14) of the high-pressure valve unit (7c) is mounted. Apparatus according to claim 10, characterized in that the pressure detection unit (19) is arranged on a high pressure component facing away from the end of a hollow piston rod (4) formed in the pressure port (33). Device according to one of the preceding claims, characterized in that the flushing channel (16) as a transverse bore in a valve body (14) of the high-pressure valve unit (7a-c) is formed.

Images