Device and method for calibrating a sealing ring to an injector

Abstract

A device (1) for calibrating a sealing ring (42) on an injector (40), in particular on a hydrogen injector (40), comprises: a mounting piece (10) with an axially extending bore (11, 12) designed to receive at least one section (41, 43, 45) of the injector (40); wherein at least in a first bore region (11) an internal thread (13) is formed; and a calibration piece (20) with an external thread (23) that can be screwed into the internal thread (13) formed in the mounting piece (10). The calibration piece (20) has a calibration piece bore (24) that extends axially through the calibration piece (20).A diameter (d2) of the calibration piece bore (24) is selected such that the calibration piece (20) presses the sealing ring (42) in a defined manner into a groove (47) formed in the injector (40) when the calibration piece (20) is moved in the axial direction over the sealing ring (42) arranged in the groove (47).

Description

[0001] The invention relates to a device and a method for calibrating a sealing ring on an injector; in particular on a hydrogen injector intended for injecting hydrogen into the combustion chamber of a hydrogen engine. State of the art

[0002] To inject hydrogen and other fluid energy carriers into the combustion chamber of an internal combustion engine, injection valves, also known as "injectors", are used.

[0003] These injectors are sealed against the engine housing by sealing rings, particularly Teflon rings. For repair and / or maintenance purposes, it may be necessary to remove the sealing ring from the injector and install a new one.

[0004] The new sealing ring must be pressed into a groove formed on the circumference of the injector to a specified dimension. This process is also known as calibration.

[0005] It is an object of the invention to provide a cost-effective device and a cost-effective method that facilitate the application and calibration of sealing rings on hydrogen injectors. Disclosure of the invention

[0006] A device according to the invention, also referred to as an "injector ring calibration tool," comprises a mounting piece with an axially extending bore designed to receive at least one section of the injector, wherein at least one portion of the bore has an internal thread. The device also comprises a calibration piece with an external thread that can be screwed into the internal thread formed in the mounting piece. The calibration piece has a calibration bore extending axially through the calibration piece. The diameter of the calibration bore is selected such that the calibration piece presses the sealing ring in a defined manner into a groove formed in the injector when the calibration piece is moved axially over the sealing ring arranged in the groove.

[0007] A method according to the invention for calibrating a sealing ring on an injector, in particular on a hydrogen injector, comprises: applying a device according to the invention to a partial area of ​​the injector such that the calibration element of the device faces an injection-side end of the injector, wherein the external thread formed on the calibration element is screwed into the internal thread formed in the mounting piece. The method further comprises applying the sealing ring to the injector between the injection-side end of the injector and the calibration element, and unscrewing the calibration element from the mounting piece so that the bore of the calibration element moves over the sealing ring and thereby calibrates the sealing ring on the injector.

[0008] An inventive device and a method according to the invention make it possible, particularly also under workshop conditions, to quickly and safely apply the sealing ring to an injector and to calibrate it in a groove formed on the injector.

[0009] The screwing motion between the internal thread and the external thread allows sufficient force to be generated by hand to move the calibration piece onto and over the sealing ring in order to calibrate the sealing ring on the injector, especially in the groove formed in the injector.

[0010] The risk of damage to the injector and / or injury during calibration of the sealing ring can be significantly reduced by using a device according to the invention.

[0011] With the aid of a device according to the invention, the calibration of the sealing ring can be carried out reproducibly with consistent results.

[0012] A device according to the invention is reusable and easy to use.

[0013] The investment costs for a device according to the invention are quickly amortized by the fast operating time of approximately 10 seconds.

[0014] In one embodiment, the calibration piece is rotated no faster than half a revolution per second to allow the sealing ring to align correctly in the groove.

[0015] In one embodiment, the bore in the mounting piece is designed as a stepped bore with a first bore section and a second bore section. The first bore section has a different diameter than the second bore section. In this way, a stop is formed in the bore of the mounting piece, which makes it possible to position the mounting piece in a defined position against a step formed on the injector.

[0016] In one embodiment, the calibration piece has a first cylindrical section and a second cylindrical section. The first and second cylindrical sections are arranged coaxially along the axial direction, and the second cylindrical section has a larger outer diameter than the first. The first cylindrical section of the calibration piece can be inserted into the bore formed in the mounting piece to connect the calibration piece to the mounting piece.

[0017] In particular, the external thread can be formed on the first cylindrical area of ​​the calibration piece.

[0018] In one embodiment, the calibration piece bore formed in the calibration piece has a first calibration piece bore area and a second calibration piece bore area. The first calibration piece bore area has a different diameter than the second calibration piece bore area. In particular, the first calibration piece bore area can have a larger diameter than the second calibration piece bore area.

[0019] In one embodiment, the first calibration piece bore area has a diameter in the range of 12 mm to 16 mm, in particular a diameter of 14.9 mm. Such a diameter of the first calibration piece bore area makes it possible to insert at least a partial portion of the injector into the first calibration piece bore area.

[0020] In one embodiment, the second calibration piece bore area has a diameter in the range of 10 mm to 12 mm, in particular a diameter of 11.25 mm.

[0021] The diameter of the second calibration piece bore area is crucial for the correct calibration of the sealing ring. Therefore, the diameter of this second calibration piece bore area depends on the dimensions of the injector onto which the sealing ring is to be fitted and on the dimensions, particularly the diameter, of the sealing ring itself. Consequently, the second diameter may need to be adjusted to the dimensions of the injector and / or the sealing ring for which the device is intended.

[0022] In one embodiment, the calibration piece bore area has an outer section with rounded walls. The walls of the rounded outer section can, in particular, have a radius of curvature of approximately 50 mm. The rounded walls allow the second calibration piece bore area to be slid onto and over the sealing ring without the sealing ring obstructing the movement of the calibration piece.

[0023] In one embodiment, knurling is formed at least on a partial area of ​​the outer circumferential surface of the mounting piece and / or at least on a partial area of ​​the outer circumferential surface of the second cylindrical area of ​​the calibration piece in order to improve the handling and in particular the gripping of the mounting piece and the calibration piece.

[0024] In one embodiment, the external and internal threads are designed as M27 threads. While the external and internal threads can also be designed as other threads, an M27 thread has proven well-suited for moving the calibration piece over the sealing ring with reasonable force and at the correct speed.

[0025] In the following, exemplary embodiments of a device and a method according to the invention are described with reference to the accompanying figures. Brief description of the characters Fig. Figure 1 shows a perspective view of an injector with a sealing ring. Fig. Figure 2 shows a perspective view of a device according to the invention. Fig. Figure 3 shows a sectional view of the device according to the invention. Fig. Figure 4 shows a front view of the mounting piece of the device according to the invention. Fig. Figure 5 shows a section through the installation piece. Fig. Figure 6 shows a perspective view of the calibration piece of the device according to the invention. Fig. Figure 7 shows a section through the calibration piece according to the invention. Fig. Figure 8 shows a front view of the calibration piece. Fig. Figure 9 shows a front area of ​​an injector without a sealing ring. Fig. Figure 10 shows the device according to the invention on a front area of ​​the injector. Fig. Figure 11 shows how a sealing ring is applied to the front section of the injector using a suitable application tool. Fig. Figure 12 shows the sealing ring on the injector before calibration. Fig. Figure 13 shows how the calibration piece is moved over the sealing ring attached to the injector. Character description

[0026] Fig. Figure 1 shows a perspective view of an injector 40, in particular a hydrogen injector 40, with a sealing ring 42, in particular a Teflon ring 42.

[0027] The injector 40 is essentially cylindrical. The injector 40 has several cylindrical sections 41, 43, 45, which are arranged coaxially in an axial direction of the injector 40 and which have different diameters, decreasing particularly in the axial direction of the injector 40. A groove 47 is formed on a front section 41 of the injector 40, which has the smallest diameter of all sections 41, 43, 45, in which the sealing ring 42 is arranged.

[0028] The invention relates to a device 1 and a method for calibrating the sealing ring 42 on the injector 40.

[0029] Fig. Figure 2 shows a perspective view of such a device 1 according to the invention, which is also referred to as the “injector ring calibration tool”. Fig. Figure 3 shows a cross-section through the area in the Fig. 2 Device shown 1.

[0030] The device 1 is essentially cylindrical and comprises a cylindrical mounting piece 10 and a cylindrical calibration piece 20, which extend coaxially along a common central axis Z in the axial direction.

[0031] A central bore 2, which is provided and designed to receive at least one section 41, 42, 43 of the injector 40, extends along the central axis Z through the device 1.

[0032] At least on parts of the outer circumferential surfaces of the fixture 10 and the calibration piece 20, knurling can be provided to facilitate gripping, holding and moving the fixture 10 and the calibration piece 20.

[0033] Fig. Figure 4 shows a front view of the plant component 10 and Fig. Figure 5 shows a section through the installation piece 10.

[0034] The component 10 can have a total length L of 35 mm to 45 mm, in particular a total length L of 40 mm.

[0035] The piece of equipment 10 points to the one in the Fig. Figure 5, shown on the left, shows a first bore area 11, on the circumference of which an internal thread 13 is formed. The first bore area 11 can have a first depth T1 in the range of 18 mm to 22 mm, in particular a first depth T1 of 20 mm.

[0036] An outer edge 14 of the first bore area 11 is chamfered at approximately 45° over a length between 1 mm and 2 mm, in particular over a length of 1.5 mm.

[0037] On the in the Fig. On the right-hand side shown in Figure 5, the component 10 has a second bore area 12.

[0038] The two bore areas 11, 12 extend coaxially along the central axis Z of the fixture 10.

[0039] The second bore area 12 has a radially outer area 12a, which has an inner diameter D a in the range of 25 mm to 27 mm, in particular an inner diameter D a of 26 mm, and a depth T a between 10 mm and 14 mm, in particular a depth T a has 12 mm.

[0040] The second bore area 12 also has an inner area 12b, which adjoins the outer area 12a within the fixture 10. The inner area 12b has an inner diameter D i between 16 mm and 18 mm, in particular an inner diameter D i of 17.6 mm. The inner area 12b can have a depth T i between 2 mm and 4 mm, in particular a depth T i of 3 mm.

[0041] The stepped transition between the outer region 12a and the inner region 12b of the second bore region 12 forms a stop 15 against which a corresponding step, formed between two adjacent sections 41, 43, 45 of the injector 40, abuts when the mounting piece 10 is applied to the injector 40 as intended, as is the case, for example, in the Fig. Figure 10 shows the position of the fixture 10 along the central axis Z of the injector 40, which is thus determined by the stop 15.

[0042] Fig. Figure 6 shows a perspective view of the calibration piece 20 of a device 1 according to the invention. Fig. Figure 7 shows a section through the calibration piece 20 and Fig. Figure 8 shows a front view of the calibration piece 20 from the one in the Fig. 6 and Fig. 7 on the right-hand side.

[0043] The calibration piece 20 has a first cylindrical area 21 with a first outer diameter a1, and a second cylindrical area 22 with a second outer diameter a2, which is larger than the first outer diameter a1 (a2 > a1).

[0044] An external thread 23, in particular an M27 external thread, is formed on the first cylindrical area 21.

[0045] An external one, in the Fig. The end 28 of the first cylindrical region 21, as shown on the right, can be chamfered. In particular, the outer end 28 of the first cylindrical region 21 can be chamfered at an angle of 45° over a length of 1.5 mm.

[0046] The first cylindrical area 21 can have a length b1 of 20 mm to 24 mm in the axial direction, in particular a length b1 of 22 mm.

[0047] The second outer diameter a2 of the second cylindrical area 22 can be an outer diameter a2 in the range between 45 mm and 55 mm, in particular an outer diameter a2 of 50 mm.

[0048] The second cylindrical area 22 can have a length b2 between 8 mm and 12 mm in the axial direction, in particular a length b2 of 10 mm.

[0049] In the calibration piece 20 a calibration piece bore 24 is formed which extends along a central axis Z in the axial direction through the calibration piece 20.

[0050] In one of the Fig. The first calibration piece bore area 24a shown on the right, which extends in particular through the first cylindrical area 21 of the calibration piece 20, has a first diameter d1.

[0051] The first calibration piece bore area 24a can, for example, have a first diameter d1 between 14 mm and 16 mm, in particular a first diameter d1 of 14.9 mm.

[0052] The calibration piece bore 24 has one in the Fig. 8 shown on the left, second calibration piece bore area 24b.

[0053] The second diameter d2 of the second calibration piece bore area 24b is crucial for the correct calibration of the sealing ring 42. The second diameter d2 of the second calibration piece bore area 24b therefore depends on the dimensions of the injector 40 onto which the sealing ring 42 is to be mounted, and on the dimensions, in particular the diameter, of the sealing ring 42. The second diameter d2 must therefore be adapted accordingly to the dimensions of the injector 40 and / or the sealing ring 42 for which the device 1 is to be used.

[0054] The second calibration piece bore area 24b can, for example, have a second diameter d2 between 10 mm and 12 mm, in particular a second diameter d2 of 11.25 mm.

[0055] An outer section 25 of the second calibration piece bore area 24b, located on the side of the second calibration piece bore area 24b facing away from the first calibration piece bore area 24a, widens outwards to facilitate the insertion of the sealing ring 42 into the calibration piece bore 24.

[0056] The wall of the outer section 25 can in particular be designed with a curvature having a radius of curvature R of 50 mm.

[0057] The wall of the second calibration piece bore area 24b, including the outer section 25, is formed with a particularly smooth surface, in particular with a surface roughness of Rz 2 or less. This allows the second calibration piece bore area 24b to be slid over a sealing ring 42, which is mounted on an injector 42, with particularly low friction.

[0058] Due to the smooth surface of the wall of the second calibration piece bore area 24b, the calibration piece 20 can be moved over the sealing ring 42 without changing the position of the sealing ring 42 along the axial direction of the injector 40.

[0059] The component 10 is preferably made of stainless steel. However, it can also be made of another type of steel that receives a suitable surface treatment.

[0060] The calibration piece 20 can in particular be made from AlMGSi1 (3.2315), which has the necessary good sliding properties and meets the requirements of EU Directive 2011 / 65 / EU (RoHS Directive).

[0061] The following refers to the Fig. Sections 9 to 13 describe a method for calibrating a sealing ring 42 on an injector 40 using a device 1 according to the invention.

[0062] Fig. Figure 9 shows a perspective view of a front area of ​​the injector 40 on which no sealing ring 42 is applied, or from which a previously applied sealing ring 42 has been removed.

[0063] A groove 47 for receiving the sealing ring 42 is formed on the foremost section 47 of the injector 40.

[0064] Any existing sealing ring 42 must be removed from the injector 40 according to the manufacturer's instructions. The groove 47 at the tip of the injector 40 must be cleaned with a clean, lint-free cloth, and any residues present, such as carbon deposits, must be removed without damaging the groove 47.

[0065] As a first step, which takes place in the Fig. As shown in Figure 10, a device 1 according to the invention is placed on the front sections 41, 43, 45 of the injector 40 until the stop 15 formed between the two bore areas 11, 12 in the mounting piece 10 is at the step between the second section 43 and the third section 45 (see Figure 10). Fig. 1) of the injector 40, strikes, so that the position of the device 1 on the injector 40 is defined by the interaction of the stop 15 with the stage.

[0066] The external thread 23 formed on the first cylindrical area 21 of the calibration piece 20 is completely screwed into the internal thread 13 formed in the mounting piece 10.

[0067] In a subsequent step, which in the Fig. As shown in Figure 11, a sealing ring 42 is applied to the front section 41 of the injector 40 using a suitable application tool 50, in particular using an application sleeve 50, and inserted into the groove 47 formed in the injector 40 for receiving the sealing ring 42 (see Figure 11). Fig. 9) is positioned. The application tool 50 is then removed from the injector 40.

[0068] After removing the application tool 50 (see Fig. 12) The correct position of the sealing ring 42 in the groove 47 formed on the injector 40 is checked again.

[0069] In the next step, the calibration piece 20 is rotated relative to the mounting piece 10. The mounting piece 10 is held with one hand, and the external thread 23 formed on the first cylindrical area 21 of the calibration piece 20 is unscrewed with the other hand from the internal thread 13 formed in the mounting piece 10, without changing the position of the mounting piece 10 in the axial direction of the injector 40.

[0070] Through the interaction of the external thread 23 with the internal thread 13, the calibration piece 20 moves along the axial direction of the injector 40 towards the front end of the injector 40 over the sealing ring 42 arranged in the groove 47 of the injector 40, as shown in the Fig. 13 is shown.

[0071] During this movement of the calibration piece 20, the wall of the second calibration piece bore area 24b presses the sealing ring 42 into the groove 47 formed on the first area 41 of the injector to the dimension specified by the diameter d2 of the second calibration piece bore area 24b. The sealing ring 42 is thus calibrated by the calibration piece 20 "driving over" it in the groove 47.

[0072] The rotation of the calibration piece 20 should not be faster than half a revolution per second in order to allow the sealing ring 42 to align itself correctly in the groove 47.

[0073] Once the calibration piece 20 has been completely moved over the sealing ring 42 in this manner, it can be unscrewed entirely from the mounting piece 10 and removed from the injector 40. After the calibration piece 20 has been removed, the mounting piece 10 is also carefully removed from the injector 40, ideally without touching the sealing ring 42.

[0074] One injector 40 remains with a sealing ring 42 calibrated in the groove 47 of the injector 40, as shown in the Fig. 1 is shown.

Claims

[1] Device (1) for calibrating a sealing ring (42) on an injector (40), in particular on a hydrogen injector (40), wherein the device (1) comprises: a mounting piece (10) with a bore (11, 12) extending in an axial direction, which is designed to receive at least one section (41, 43, 45) of the injector (40); wherein at least in one part of the bore (11, 12) an internal thread (13) is formed; a calibration piece (20) with an external thread (23) which can be screwed into the internal thread (13) formed in the mounting piece (10); wherein the calibration piece (20) has a calibration piece bore (24) which extends axially through the calibration piece (20), and wherein a diameter (d2) of the calibration piece bore (24) is selected such that the calibration piece (20) presses the sealing ring (42) in a defined manner into a groove (47) formed in the injector (40) when the calibration piece (20) is moved in the axial direction over the sealing ring (42) arranged in the groove (47). [2] Device (1) according to claim 1, wherein the bore (11, 12) in the mounting piece (10) is designed as a stepped bore (11, 12) with a first bore area (11) and with a second bore area (12), wherein the first bore area (11) has a different diameter than the second bore area (12). [3] Device (1) according to claim 1 or 2, wherein a stop (15) is formed in the bore (11, 12) in the attachment piece (10) which makes it possible to position the attachment piece (10) in a defined position on a step formed on the injector (40). [4] Device (1) according to one of the preceding claims, wherein the calibration piece (20) has a first cylindrical area (21) and a second cylindrical area (22), wherein the first cylindrical area (21) and the second cylindrical area (22) are arranged coaxially along the axial direction; wherein the second cylindrical region (22) has a larger outer diameter (a2) than the first cylindrical region; and wherein the external thread (23) is formed on the first cylindrical area (21). [5] Device (1) according to one of the preceding claims, wherein the calibration piece bore (24) formed in the calibration piece (20) has a first calibration piece bore area (24a) and a second calibration piece bore area (24b), wherein the first calibration piece bore area (24a) has a different diameter than the second calibration piece bore area (24b), wherein the first calibration piece bore area (24a) in particular has a larger diameter than the second calibration piece bore area (24b). [6] Device (1) according to claim 5, wherein the first calibration piece bore area (24a) has a diameter (d1) in the range of 12 mm to 16 mm, in particular a diameter (d1) of 14.9 mm; and / or wherein the second calibration piece bore area (24b) has a diameter (d2) in the range of 10 mm to 12 mm, in particular a diameter (d2) of 11.25 mm. [7] Device (1) according to claim 5 or 6, wherein the second calibration piece bore area (24b) has a rounded outer section (25), wherein the rounded outer section (25) in particular has a radius of curvature (R) of 50 mm. [8] Device (1) according to one of claims 4 to 7, wherein at least a knurling is formed on at least a partial area of ​​the outer circumferential surface of the mounting piece (10) and / or at least on a partial area of ​​the outer circumferential surface of the second cylindrical area (22) of the calibration piece (20). [9] Device (1) according to one of the preceding claims, wherein the external thread (23) and the internal thread (13) are designed as M27 threads. [10] Method for calibrating a sealing ring (42) on an injector (40), in particular on a hydrogen injector (40), the method comprising: a device (1) according to one of the preceding claims to be applied to a partial area of ​​the injector (40) such that the calibration piece (20) of the device (1) faces an injection-side end of the injector (40), wherein the external thread (23) formed on the calibration piece (20) is screwed into the internal thread (13) formed in the mounting piece (10); to apply the sealing ring (42) between the injection-side end of the injector (40) and the calibration piece (20) to the injector (40); and to unscrew the calibration piece (20) from the mounting piece (10) so that the calibration piece bore (24) moves over the sealing ring (42) and thereby calibrates the sealing ring (42) on the injector (40); wherein the calibration piece (20) is rotated at a rate not exceeding half a revolution per second when unscrewing it from the mounting piece (10).

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