DE102008018017B4 - Sealing arrangement for a housing, pump and injection valve - Google Patents

Abstract

High-pressure sealing arrangement for a housing (12), comprising - a first housing body part (14) and a second housing body part (15), wherein the first housing body part (14) and the second housing body part (15) each have a contact region (28), so that the first Housing body part (14) stationary relative to the second housing body part (15) is arranged, - in the first housing body part (14) and the second housing body part (15) arranged in common, in the direction of a longitudinal axis (L) extending recess (16) formed is for guiding a fluid, wherein the recess (16) on the first housing body part (14) has a first wall portion (18a) and on the second housing body part (15) has a second wall portion (18b), - a sleeve (22), in the recess (16) is arranged, a in the direction of the longitudinal axis (L) extending through opening (26) and an outer sleeve wall (24), wherein the H 22 is configured so that it is deformed with the fluid at least by acting on the passage opening (26) in such a way that it interacts with the housing body parts (14, 15) in such a way that the outer sleeve wall (24) engages with the first wall section (14). 18a) a circumferential with respect to the longitudinal axis (L) first sealing region (30) and the second wall portion (18b) with respect to the longitudinal axis (L) encircling second sealing region (32) characterized in that the recess (16) in each of the housing body parts (14, 15) has a first portion (16a) with a substantially constant first cross-sectional area (A_1) and a second portion (16b) with a substantially constant second cross-sectional area (A_2), the second cross-sectional area (A_2 ) is greater than the first cross-sectional area (A_1), and the sleeve (22) is at least partially disposed in the second portions (16b) of the recess (16).

Description

The invention relates to a high-pressure sealing arrangement for a housing. The invention further relates to a pump and an injection valve.

Pumps and injectors are preferably used for injection systems for internal combustion engines of motor vehicles. On the one hand, such pumps are used in particular as high-pressure pumps for conveying fluid for these injection systems. On the other hand, such injectors are used in particular for injecting fuel into combustion chambers of the internal combustion engine under high pressure.

Injection systems for internal combustion engines of motor vehicles, for example in common-rail systems, should be able to provide the necessary volume flow and the required fluid pressure. The pumps and the injection valves in injection systems for motor vehicles are subject to heavy loads, in particular heavy mechanical stresses. In particular, large forces must be able to be absorbed by such pumps. This places high demands on the materials that make up the components of the pumps and injectors as well as on the design of the pumps and injectors. Since these pumps and injectors can be exposed to high pressures, they must withstand heavy loads.

The DE 34 01 569 A1 discloses a gap formed by two adjacent edges of a container wall composed of individual modules. The gap along with gap circumferential area is covered with a flat elastic thin-walled sealing element on the inside of the container wall.

The US 2007/0262581 A1 discloses an H-shaped ring of a resin component between a fitting and a flow path piece which forms a concavo-convex line with the flow path piece and with the fitting, respectively, which forms a sealing area.

DE 102 50 211 A1 describes a high pressure seal having a tube inserted with a first end into a first bore of a first mating part and a second end into a second bore of a second mating part to permit fluid communication between the first bore and the second bore. The high pressure seal is radially expandable about an axis to form a seal between the first and second mating parts.

In DE 102 16 280 A1 a sealing device for a high-pressure seal is described, which has a cutting edge, which allows a seal by means of plastic deformation.

WO 2007/145779 A2 discloses a tubular sealing element having inside a rigid cylindrical tube and in the outside an elastomeric sealing body, which is integrally formed on the outer surface of the tube.

The object of the invention is to provide a high-pressure sealing arrangement for a housing, by means of which a secure hydraulic sealing of the housing is achieved. The further object of the invention is to provide a pump and an injection valve, which can be operated reliably and precisely.

The object is solved by the features of the independent claims. Advantageous embodiments of the invention are characterized in the subclaims.

According to a first aspect, the invention is characterized by a high-pressure sealing arrangement for a housing, which has a first housing body part and a second housing body part, wherein the first housing body part and the second housing body part each have a contact area, so that the first housing body part is arranged stationary relative to the second housing body part in that a recess arranged in the first housing body part and the second housing body part and extending in the direction of a longitudinal axis, which is designed to guide a fluid. The recess has a first wall section on the first housing body part and a second wall section on the second housing body part. The high-pressure seal arrangement further has a sleeve which is arranged in the recess, has a passage opening extending in the direction of the longitudinal axis and an outer sleeve wall. The sleeve is formed so that it is deformed at least under the action of the passage opening with the fluid so that it cooperates with the housing body parts so that the outer sleeve wall with the first wall portion a circumferential with respect to the longitudinal axis of the first sealing region and the second wall portion forms a circumferential with respect to the longitudinal axis second sealing region.

The term housing body part is to be understood here in such a sense that the housing body part can be in particular a block-shaped part of a housing body, for example a valve body of an injection valve or a housing body of a high-pressure pump. The term Fluid is to be understood in its broader sense, so the fluid can be both a liquid and a gas. The deformation may be either plastic or elastic or a combination of plastic and elastic deformation.

The advantage of such a high-pressure seal arrangement is that an intrinsically safe seal for high-pressure sealing arrangements in housings is possible, that is to say that with increasing fluid pressure in the passage opening of the sleeve an ever better sealing can take place. Furthermore, contact surfaces between the housing body parts may have low requirements in terms of manufacturing tolerances. A heat treatment of the contact surfaces between the housing body parts can be omitted. For a cost-effective production of the housing is possible. In particular, a selection of a low-cost material for the housing body parts may be possible.

The recess in each of the housing body parts has a first portion with a substantially constant first cross-sectional area and a second portion with a substantially constant second cross-sectional area. The second cross-sectional area is larger than the first cross-sectional area. The sleeve is at least partially disposed in the second portions of the recess.

This has the advantage that the cross-sectional area of the passage opening of the sleeve can be substantially as large as the first cross-sectional area of the recess. Thus, cross-sectional constriction and thus a pressure drop in the sleeve can be avoided.

In a further advantageous embodiment, a transition section of the recess is arranged between each one of the first sections and one of the second sections, in which the cross section increases continuously from the first cross-sectional area to the second cross-sectional area. The wall sections in the transition sections each form a sealing surface for one of the sealing regions. For a simple design of the sealing area is possible and on the sealing surface of the sleeve can be exerted outwardly acting radial force. This allows a particularly high density of the sealing area can be achieved.

In a further advantageous embodiment, the sealing surfaces are formed substantially cone-shaped. This can be exercised on the sealing surface particularly easy outwardly acting radial force and thus a particularly good sealing effect can be achieved on the sealing surface.

In a further advantageous embodiment, the sleeve has at least one outer edge, which is formed such that it forms one of the sealing regions at least by acting on the through-opening with the fluid with one of the wall sections. This has the advantage that a spatially particularly well-defined sealing area and thus good sealing properties of the sealing surface are possible.

In a further advantageous embodiment, the sleeve is substantially cylindrical. This is in a simple way a precise location installation of the sleeve in the recess possible.

In a further advantageous embodiment, the sleeve is formed substantially spherical. For a simple form of the sleeve and a cost-effective design of the sleeve can be achieved.

In a further advantageous embodiment, the sleeve has an outer groove arranged in the circumferential direction with respect to the longitudinal axis. This has the advantage that the sleeve is very flexible and therefore can be in good contact with the housing body parts.

In a further advantageous embodiment, the passage opening of the sleeve has a radial expansion with respect to the longitudinal axis. For a streamlined design of the sleeve and a high sealing force between the sleeve and housing body parts are possible.

In a further advantageous embodiment, an O-ring is arranged between the outer sleeve wall and one of the wall sections. This is another sealing area with good sealing effect between the sleeve and housing body parts reachable.

In a further advantageous embodiment, the sleeve is formed of a material comprising a steel. For a mechanically robust design of the sleeve is possible.

In a further advantageous embodiment, the sleeve is formed from a material which comprises an elastomer. For a good plastic and / or elastic deformation of the sleeve under fluid loading is possible.

According to a second aspect, the invention is characterized by a pump with a high-pressure sealing arrangement according to the first aspect, wherein the housing body parts are parts of a cylinder housing of the pump. This makes it possible to use the high-pressure seal arrangement in housings for high-pressure pumps.

According to a third aspect, the invention is characterized by an injection valve with a high-pressure sealing arrangement according to the first aspect, wherein the housing body parts are parts of a valve body of the injection valve. This makes it possible to use the high-pressure seal arrangement in housings for injection valves.

The high pressure seal assembly may also be referred to as a seal assembly.

Embodiments of the invention are explained in more detail below with reference to the schematic drawings.

Show it:

1 a schematic view of a seal assembly in a first embodiment in a longitudinal section,

2 a schematic view of the seal assembly in a second embodiment in a longitudinal section,

3 a schematic view of the seal assembly in a third embodiment in a longitudinal section,

4 a schematic view of the seal assembly in a fourth embodiment in a longitudinal section,

5 a schematic view of a seal assembly in a fifth embodiment in a longitudinal section,

6 a schematic view of the seal assembly in a sixth embodiment in a longitudinal section,

7 a schematic view of the seal assembly in a seventh embodiment in a longitudinal section,

8th a schematic view of the seal assembly in an eighth embodiment in a longitudinal section,

9 a schematic view of the seal assembly in a ninth embodiment in a longitudinal section,

10 a schematic view of the seal assembly in a tenth embodiment in a longitudinal section, and

11 a schematic view of a pump with a seal assembly in a longitudinal section.

Elements of the same construction or function are provided across the figures with the same reference numerals.

The 1 to 10 show a seal arrangement 10 with a housing 12 ,

The housing 12 has a first housing body part 14 and a second housing body part 15 on. The first housing body part 14 is with the second housing body part 15 firmly coupled so that the two housing body parts 14 . 15 are arranged strongly to each other.

In the housing body parts 14 . 15 a recess is arranged which extends in the direction of a longitudinal axis L. The recess 16 has a first section 16a with a substantially constant first cross-sectional area A_1 and a second portion 16b with a substantially constant second cross-sectional area A_2. Between the first section 16a and the second section 16b the recess 16 is a transitional section 16c arranged. In the transition section 16c the recess 16 takes the cross section of the first cross-sectional area A_1 of the first section 16a the recess 16 up to the second cross-sectional area A_2 of the second section 16b the recess 16 to. The transition section 16c the recess 16 forms either an extension or a narrowing region of the recess 16 ,

The recess 16 forms on the first housing body part 14 a first wall section 18a and on the second housing body part 15 a second wall section 18b out. The wall sections 18a and 18b make up the wall together 18 the recess 16 in the housing body parts 14 . 15 out.

The wall sections 18a and 18b in the transitional sections 16c each form a sealing surface 19 for a sealing area 30 . 32 , The sealing surfaces 19 are preferably formed substantially cone-shaped ( 1 to 8th ). The sealing surfaces 19 may also be formed as the surface of an ellipsoid ( 9 ).

In the recess 16 especially in the second section 16b and the transition section 16c the recess 16 , is a sleeve 22 arranged, which is an outer sleeve wall 24 and a through hole 26 Has. The passage opening 26 extends substantially in the direction of the longitudinal axis L.

In the embodiments of the seal assembly 10 as they are in the 2 and 8th is shown, the housing has 12 a third further Housing body part 20 on, between the first housing body part 14 and the second housing body part 15 is arranged.

Between the housing body parts 14 . 15 . 20 is each a contact area 28 designed so that is a fixed arrangement of the housing body parts 14 . 15 . 20 allows each other.

At the longitudinal ends of the sleeve 22 are outer edges 40 educated. These are designed to be one of the edges 40 together with the wall section 18a the first sealing area 30 and another of the edges 40 together with the wall section 18b the second sealing area 32 forms. Through the outer edges 40 is a spatially particularly well-defined sealing area 30 . 32 given. Thus, good sealing properties of the sealing surface 19 possible.

In the in the 1 . 2 . 4 . 6 . 7 . 8th and 10 illustrated embodiments of the seal assembly 10 is the sleeve 22 formed substantially cylindrical. In this case, a particularly simple position-accurate installation of the sleeve 22 into the recess 16 possible. The cylindrical sleeves 22 have a substantially cone-shaped chamfer 39 on, by means of the outer edge 40 is formed, and substantially in the region of the transition section 16c the recess 16 is arranged.

In 3 is an embodiment of the seal assembly 10 shown at the sleeve 22 is formed substantially spherical. In the case of a spherical sleeve 22 this can be made particularly cost-effective, since as a starting material only balls with corresponding through holes 26 must be provided.

The sleeve 22 is formed of a material which preferably comprises a steel and / or an elastomer. With a steel can be a mechanically robust design of the sleeve 22 enable. By an elastomer, a good plastic and / or elastic deformation of the sleeve 22 be possible under exposure to a fluid.

In the embodiment of the sealing arrangement 10 of the 4 is in the sleeve 22 with respect to the longitudinal axis L in the circumferential direction an outer groove 34 arranged. The sleeve 22 is very flexible and works well with the housing parts 14 . 15 be in touch.

The embodiment of the seal arrangement 10 of the 5 shows the sleeve 22 with a radial expansion with respect to the longitudinal axis L. 35 the passage opening 26 , Both the groove 34 in the sleeve 22 as well as the expansion 35 the passage opening 26 serve to weaken the sleeve 22 in the radial direction in a spatially defined area and can thus to a high flexibility of the sleeve 22 in the radial direction.

In 6 is the sleeve 22 with grooves 34 shown, in each case an O-ring 36 is arranged. The O-ring 36 the sleeve 22 forms together with the wall sections 18a . 18b the Wall 18 the housing body parts 14 . 15 another sealing area 38 out.

In the in 7 shown embodiment of the seal assembly 10 show the first sections 16a the recess 16 which are in the first housing body part 14 and in the second housing body part 15 are arranged, each having different first cross-sectional areas A_1. Accordingly, the cross-sectional area of the passage opening changes 26 the sleeve 22 so that the sleeve 22 here as a constriction or extension element for the recess 16 in the case 12 can serve.

8th shows an offset arrangement of the first sections 16a the recess 16 in the housing body parts 14 . 15 , The second section is corresponding 16b the recess 16 diagonally to the first sections 16a the recess 16 arranged. This is the sleeve 22 with its longitudinal axis L also obliquely opposite the first sections 16a the recess 16 arranged. This allows bridging the offset between the first section 16a the recess 16 in the first housing body parts 14 and the first section 16a the recess 16 in the second housing body part 15 ,

9 shows the sleeve 22 with ellipsoidal sections 44 that are in the sealing areas 30 . 32 at ellipsoidal transition sections 16c the recess 16 issue. This allows a particularly good sealing effect between the ellipsoidal sections 44 and the sealing surfaces 19 the ellipsoidal transition sections 16c ,

In 10 are the housing body parts 14 . 15 with annular projections 42 formed, which together with the outer sleeve wall 24 the sleeve 22 additional sealing areas 38 between the sleeve 22 and the housing 12 form. This allows a particularly good sealing effect between the sleeve 22 and the housing body parts 14 . 15 ,

11 shows a pump 50 with a cylinder housing 52 in which a cylinder room 54 is arranged. The cylinder space 54 is via a cylinder room drain line 58 with a valve 56 and subsequently at the contact area 28 between the first housing body part 14 and the second housing body part 15 of the cylinder housing 52 with the seal arrangement 10 hydraulically coupled. In the recess 16 the housing body parts 14 . 15 is the sleeve 22 with the passage opening 26 arranged, the fluid flow between the cylinder space drain line 58 and the recess 16 allows. An application of the sealing arrangement 10 in housings for high-pressure pumps is particularly advantageous because these pumps are usually exposed to high pressures.

In a similar way, the seal arrangement 10 be arranged in a recess of an injection valve, such as a fuel channel leading. The housing body parts are in this case parts of a valve body of an injection valve. An application of the sealing arrangement 10 in housings for injectors is particularly advantageous because these valves are usually exposed to high pressures.

The following is the operation of the seal assembly 10 for the housing 12 be shown in detail:
First, the recess 16 subjected to fluid, so that the fluid in the through hole 26 passes, under pressure, the sleeve 22 widens in the radial direction.

This forms the edges 40 the sleeve 22 the sealing areas 30 . 32 between the housing body parts 14 . 15 and the sleeve 22 out. In this case, the outer sleeve wall forms 24 with the first wall section 18a The circumferential with respect to the longitudinal axis L first sealing area 30 and the second wall section 18b the circumferential with respect to the longitudinal axis L second sealing region 32 out.

In the embodiments of the 6 and 10 the seal arrangement 10 be by the admission of the passage opening 26 the sleeve 22 with fluid the other sealing areas 38 educated. This happens at contact surfaces between the O-ring 36 and the housing body parts 14 . 15 or the sleeve 22 and the projections 42 the housing body parts 14 . 15 ,

The deformation of the sleeve 22 Under pressure, on the one hand elastically. That means that the sleeve 22 after the end of the pressurization with fluid returns to the initial state. On the other hand, the deformation of the sleeve 22 plastically done under pressure, leaving the sleeve 22 after the end of the fluid admission of the passage opening 26 remains in the then achieved shape with pressure.

By the formation of the sealing areas 30 . 32 . 38 need the contact areas 28 between housing body parts 14 . 15 no longer be processed very accurately, as they no longer have to take over sealing function. This results in cost advantages in the production and during transport and assembly of the unit with the housing 12 , In addition, the choice of materials may also be the housing body parts 14 . 15 . 20 done so that inexpensive materials are used. In addition, a special heat treatment of the contact areas 28 between the housing body parts 14 . 15 . 20 omitted. By such a trained sleeve 22 with the passage opening 26 can be a good sealing function between the sleeve 22 and the housing body parts 14 . 15 . 20 guaranteed.

LIST OF REFERENCE NUMBERS

10

sealing arrangement

12

casing

14

1. housing body part

15

2. Housing body part

16

recess

16a, 16b

first, second section of the recess

16c

Transition portion of the recess

18

wall

18a, 18b

wall sections

19

sealing surface

20

3. housing body part

22

shell

24

outer sleeve wall

26

Through opening

28

Contact area between two housing body parts

30

1. Sealing area

32

2. Sealing area

34

Groove in the sleeve

35

Expansion of the passage opening

36

O-ring

38

additional sealing area

39

Chamfer of the sleeve

40

Edge of the sleeve

42

Projection of the housing body parts

44

Sections of the sleeve

50

pump

52

cylinder housing

54

cylinder space

56

Valve

58

Cylinder chamber drain pipe

A_1

1. Cross-sectional area

A_2

2. Cross-sectional area

L

longitudinal axis

Claims (13)

High-pressure sealing arrangement for a housing ( 12 ), comprising - a first housing body part ( 14 ) and a second housing body part ( 15 ), wherein the first housing body part ( 14 ) and the second housing body part ( 15 ) one contact area each ( 28 ), so that the first housing body part ( 14 ) stationary relative to the second housing body part ( 15 ), - one in the first housing body part ( 14 ) and the second housing body part ( 15 ) arranged in common, in the direction of a longitudinal axis (L) extending recess ( 16 ), which is designed to guide a fluid, wherein the recess ( 16 ) on the first housing body part ( 14 ) a first wall section ( 18a ) and on the second housing body part ( 15 ) a second wall section ( 18b ), - a sleeve ( 22 ), which are in the recess ( 16 ) is arranged, a in the direction of the longitudinal axis (L) extending through opening ( 26 ) and an outer sleeve wall ( 24 ), wherein the sleeve ( 22 ) is formed so that it at least under the action of the passage opening ( 26 ) is deformed with the fluid such that it with the housing body parts ( 14 . 15 ) cooperates so that the outer sleeve wall ( 24 ) with the first wall section ( 18a ) a with respect to the longitudinal axis (L) encircling first sealing area ( 30 ) and with the second wall section ( 18b ) a with respect to the longitudinal axis (L) encircling second sealing area ( 32 ) is characterized in that the recess ( 16 ) in each of the housing body parts ( 14 . 15 ) a first section ( 16a ) having a substantially constant first cross-sectional area (A_1) and a second portion ( 16b ) having a substantially constant second cross-sectional area (A_2), the second cross-sectional area (A_2) being larger than the first cross-sectional area (A_1), and the sleeve ( 22 ) at least partially in the second sections ( 16b ) of the recess ( 16 ) is arranged. High pressure seal arrangement according to claim 1, wherein between each one of the first sections ( 16a ) and one of the second sections ( 16b ) a transitional section ( 16c ) of the recess ( 16 ) in which the cross section increases continuously from the first cross sectional area (A_1) to the second cross sectional area (A_2), and wherein the wall sections (A) 18a . 18b ) in the transitional sections ( 16c ) each have a sealing surface ( 19 ) for one of the sealing areas ( 30 . 32 )) form. High-pressure sealing arrangement according to claim 2, wherein the sealing surfaces ( 19 ) are formed substantially cone-shaped. High-pressure sealing arrangement according to one of the preceding claims, wherein the sleeve ( 22 ) at least one outer edge ( 40 ), which is formed such that it at least under the action of the passage opening ( 26 ) with the fluid with one of the wall sections ( 18a . 18b ) one of the sealing areas ( 30 . 32 ). High-pressure sealing arrangement according to one of the preceding claims, wherein the sleeve ( 22 ) is formed substantially cylindrical. High-pressure sealing arrangement according to one of the preceding claims, wherein the sleeve ( 22 ) is formed substantially spherical. High-pressure sealing arrangement according to one of the preceding claims, wherein the sleeve ( 22 ) in the circumferential direction with respect to the longitudinal axis (L) arranged outer groove ( 34 ) having. High-pressure sealing arrangement according to one of the preceding claims, wherein the passage opening ( 26 ) of the sleeve ( 22 ) a radially widening with respect to the longitudinal axis (L) ( 35 ) having. High pressure seal arrangement according to one of the preceding claims, wherein between the outer sleeve wall ( 24 ) and one of the wall sections ( 18a . 18b ) an O-ring ( 36 ) is arranged. High-pressure sealing arrangement according to one of the preceding claims, wherein the sleeve ( 22 ) is formed of a material having a steel. High-pressure sealing arrangement according to one of the preceding claims, wherein the sleeve ( 22 ) is formed of a material having an elastomer. Pump ( 50 ) with a high-pressure sealing arrangement according to one of the preceding claims, wherein the housing body parts ( 14 . 15 ) Parts of a cylinder housing ( 52 ) of the pump ( 50 ) are. Injection valve with a high-pressure sealing arrangement according to one of claims 1 to 11, wherein the housing body parts ( 14 . 15 ) Are parts of a valve body of the injection valve.

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