TOOL FOR REMOVING A SPARK PLUG SEAL

Description

State of the art

[0001] The present invention relates to a tool for removing a ring, in particular a metal sealing ring, from a spark plug, in particular a hook spark plug or a pre-chamber spark plug.

[0002] A tool for removing a sealing ring is known from US 3 401 445 A.

[0003] In internal combustion engines, for example, spark plugs are screwed into a threaded hole in the cylinder head using an external thread. Figure 1shows, by way of example, a hook-type spark plug 10 with a center electrode 13 and a ground electrode 14. A housing 11 has an external thread 12, with which the spark plug is screwed into a threaded bore in the cylinder head or the like. Reference numeral 15 denotes an electrical insulator. On the housing 11, a shoulder 11a is arranged between the external thread 12 and a tool attachment area 17. A metal sealing ring 16 is provided on the shoulder 11a, which, when the spark plug is screwed in, prevents gases from the combustion chamber from escaping to the outside via a gap between the spark plug and the cylinder head. When the spark plug is screwed into the cylinder head, this metal sealing ring 16 is often plastically deformed, which leads to an improved seal between the spark plug and the cylinder head. For example, during maintenance work, the spark plugs are unscrewed from the cylinder head and reused if necessary.In this case, the metal sealing ring 16 must be removed from the spark plug and replaced, which is often very difficult due to its deformation. Particular care must be taken to ensure that the thread 12 of the spark plug is not damaged when removing the metal sealing ring 16. Once the metal sealing ring has been removed, a new metal sealing ring can be pushed on and the spark plug screwed back into the cylinder head. Removing the metal sealing ring is therefore relatively time-consuming and often also results in damage to the spark plug, making it impossible to reuse. It would therefore be desirable to have a tool that makes removing the metal sealing ring from the spark plug easier. Disclosure of the invention

[0004] The tool according to the invention for removing a metal sealing ring from a spark plug with the features of claim 1 has the advantage that the metal sealing ring can be removed from the spark plug quickly and easily. There is no risk of damage to the spark plug during the process of removing the metal sealing ring, so that the spark plug can be recycled after a new metal sealing ring has been attached. This is achieved according to the invention in that the tool has a housing with a receiving space for receiving the spark plug. The housing comprises an open longitudinal side on which the receiving space is exposed and is designed to insert the spark plug into the receiving space via the open longitudinal side. Furthermore, the tool comprises a support device which projects into the receiving space.The support device is arranged such that an inserted spark plug with metal sealing ring lies in the receiving space such that the metal sealing ring at least partially rests against the support device in the axial direction of the tool. The tool further comprises a cutting device which is movable in the receiving space in the axial direction of the tool. A gap for receiving the metal sealing ring of the spark plug is formed between the cutting device and the support device. The tool further comprises an actuating device which is manually actuable and is operatively connected to the cutting device in order to carry out the axial movement of the cutting device in the receiving space. During the axial movement of the cutting device, it is moved axially into the gap between the cutting device and the support device, in which the metal sealing ring lies, in order to axially cut the metal sealing ring.This is possible because the metal sealing ring rests on the support device on one side and is cut from the other by the cutting device. This allows the metal sealing ring to be easily removed from the spark plug after removing it from the tool, or the individual parts of the metal sealing ring simply fall off.

[0005] The subclaims show preferred developments of the invention.

[0006] Preferably, the actuating device comprises a lever that is operatively connected to the cutting connection. This significantly reduces the force required to split the metal sealing ring, as the lever amplifies the force when the tool is actuated, in accordance with the lever law.

[0007] The cutting device further preferably comprises a base element on which at least one cutting edge is arranged. The base element ensures that the axial movement of the cutting device can be carried out reliably. If the cutting device has exactly one cutting edge, only one slot is made in the metal sealing ring after the tool is actuated. This makes removing the metal sealing ring from the spark plug somewhat cumbersome after the spark plug has been removed. The cutting device therefore preferably has two, three, or four cutting edges. The metal sealing ring is then divided into two, three, or four parts accordingly. This makes it easy to remove the divided metal sealing ring from the spark plug, or it falls off the spark plug automatically after the cutting process.

[0008] To ensure a uniform application of force from the cutting device to the metal sealing ring, the base element comprises a ring on which the cutting edges are arranged. The cutting edges are preferably arranged on the outer circumference of the ring.

[0009] Further preferably, the cutting edges of the cutting device are arranged so that they can be replaced. This allows the cutting edges to be replaced after a certain period of use if they become blunt through use.

[0010] According to a further preferred embodiment of the invention, the actuating device comprises a first guide element pivotally connected to the lever and a cylinder with a tapered end. The tapered end of the cylinder is in contact with the first guide element. Furthermore, the cylinder element is operatively connected to the cutting device. Thus, actuating the lever axially moves the first guide element, which transmits the movement to the cutting device via the cylinder. By designing the cylinder with a tapered end, secure axial mobility of the cutting device is ensured even when there is a certain amount of play in the individual parts of the actuating device.

[0011] Particularly preferably, the actuating device further comprises a second guide element arranged between the cylinder and the cutting device. Particularly preferably, a connecting element is provided, which is arranged on the second guide element and is operatively connected to the base element of the cutting device.

[0012] Particularly preferably, the tool further comprises a reset element that automatically resets the actuating device and the cutting device to their initial state. The reset element is preferably integrated into the actuating device, in particular between the cylinder and the second guide element. The reset element is preferably a spring, in particular a cylinder spring, with the second guide element further preferably having a spring receptacle.

[0013] Further preferably, the housing comprises an outlet opening in the axial direction, from which an inserted spark plug partially exits into the environment. This allows, in particular, the axial length of the tool to be reduced, and in particular, spark plugs with different axial lengths can be easily machined with the same tool in order to remove the respective metal sealing rings on the spark plugs.

[0014] The receiving space of the tool can be designed relatively large, since it is not necessary for the spark plug to support itself on one side of the receiving space; rather, it is sufficient for the removal of the metal sealing ring if the metal sealing ring is supported on the support device. Preferably, the receiving space has a shoulder so that the receiving space essentially corresponds to the outer contour of the spark plug.

[0015] For space-saving storage, the housing preferably has a recess on an outer side for accommodating the lever. A holding device for the lever can also be provided so that it remains positioned in the recess on the outside of the housing. The holding device can, for example, be an undercut or a clipping of the lever into a correspondingly designed holding device.

[0016] The tool according to the invention can be used with all types of spark plugs, especially hook-type spark plugs and pre-chamber spark plugs. The housing of the tool is preferably made of a metal material. drawing

[0017] A preferred embodiment of the invention will be described in detail below with reference to the accompanying drawings. In the drawing: Figure 1 is a schematic, only partially sectioned view of a hook spark plug with a metal sealing ring to be removed, Figure 2 is a schematic, perspective view of a tool according to the invention with a spark plug inserted into the tool, Figure 3 is a schematic side view of the tool of Figure 2 , and Figure 4 a schematic partial sectional view of the tool of Figure 2 . Preferred embodiment of the invention

[0018] The following is based on the Figures 1 to 4 a tool 1 according to a preferred embodiment of the invention is described in detail.

[0019] Tool 1 is able to Figure 1 to safely remove the metal sealing ring 16 located on a spark plug. The metal sealing ring 16 may also be plastically deformed and very firmly bonded to the spark plug.

[0020] The Figures 2 and 3show an overall view of the tool 1. The tool 1 comprises a housing 2 made of a metal material with a receiving space 3 for the spark plug. Figure 2 shows the inserted state of the spark plug 10 in the receiving space 3. The housing 2 has an open longitudinal side on which the receiving space 3 is exposed and is designed so that the spark plug 10 can be inserted into the receiving space 3.

[0021] The housing 2 has an outlet opening 30 in an axial direction XX, from which, as in Figure 2 As shown, the spark plug 10 partially emerges from the tool 1. This outlet opening 30 makes the tool suitable for spark plugs with a wide variety of geometric dimensions. The receiving space 3 further includes a shoulder 31, so that the receiving space essentially corresponds to the outer contour of the spark plug.

[0022] The tool 1 further comprises a support device 4, which projects into the receiving space 3. The support device 4 is also shown in detail in Figure 4 The support device 4 is an annular disc protruding into the receiving space 3, which is firmly connected to the housing 2, for example, via a welded joint. Alternatively, the support device is formed integrally with the housing 2.

[0023] The support device 4 is designed so that when the spark plug is inserted, the metal sealing ring 16 to be removed rests on one side of the support device 4.

[0024] The tool 1 further comprises a cutting device 5, which is movable in the receiving space 3 in the axial direction XX of the tool. The cutting device 5 is in the Figure 4shown starting position such that a gap 8 is formed between the cutting device 5 and the support device 4. The metal sealing ring 16 is positioned in this gap 8 when the spark plug is inserted. This is shown in Figure 4 indicated by the dashed metal sealing ring 16.

[0025] Furthermore, the tool 1 comprises an actuating device 6, which can be operated manually. The actuating device 6 is operatively connected to the cutting device 5 in such a way that an axial movement of the cutting device 5 in the receiving space 3 can be carried out. In this case, the cutting device 5 is moved into the gap 8 in order to axially divide the metal sealing ring 16. This is shown in Figure 4 indicated by arrow A.

[0026] The actuating device 6 comprises, as can be seen from the Figures 3 and 4As can be seen, a lever 60 which can be operated manually and which is hinged to the housing 2 of the tool. The joint 65 is in Figure 4shown schematically. The actuating device 6 further comprises a first guide element 61, which is guided for axial movement in the receiving space 3. Furthermore, the actuating device 6 comprises a cylinder 63 with a tapered end 63a. The tapered end 63a is in contact with the first guide element 61. The other end of the cylinder 63 is formed with a flange 63b, which serves to receive one end of a return element 7. The actuating device 6 further comprises a second guide element 62, through which a rod 64 is passed. A spring holder 64a is arranged on the rod 64 and is in contact with the other end of the return element 7. The rod 64 is fixedly connected to a cutting plate 51 of the cutting device 5, for example by means of a welded connection, in order to transmit the axial movement to the cutting device 5.Four rods 52 are arranged on the cutting plate 51, to the end of which a ring 53 is attached, on which two cutting edges 50 are arranged. The cutting edges 50 are arranged at opposite positions on an outer circumference of the ring 53. The width of the cutting edges 50 is equal to or greater than the width of the metal sealing ring 16 to ensure that the latter is completely cut.

[0027] Thus, the return element 7, which in this embodiment is a cylindrical spring, is part of the actuating device 6. The actuating force exerted via the lever 60 is thus transmitted via the first guide element 61, the cylinder 63, the return element 7, the rod 64, the cutting plate 51, the rods 52, and the ring 53. As a result, the cutting device 5 is pressed in the direction of arrow A against the metal sealing ring 16, which is supported on the support device 4, and is cut when the corresponding force is applied.

[0028] In order to ensure a reset, the reset element 7 is firmly connected on the one hand to the cylinder 63 and on the other hand to the rod 64.

[0029] Thus, the tool 1 according to the invention can be used to reliably separate a metal sealing ring 16 from a spark plug 10 by cutting it. In this exemplary embodiment, the cutting device 5 has two cutting edges 50. However, it should be noted that it is also possible to use only one cutting edge or, particularly preferably, to use three or four cutting edges to divide the metal sealing ring 16 into several pieces.

[0030] To enable secure insertion of the spark plug 10 into the receiving space 3, the receiving space 3 has approximately the shape of an outer contour of the spark plug. By means of the support device 4, which is essentially U-shaped to enable lateral insertion of the spark plug into the tool, the spark plug with metal sealing ring 16 can be securely inserted into the tool such that the metal sealing ring 16 is positioned in the gap 8 between the cutting device 5 and the support device 4. The gap 8 is selected such that metal sealing rings of different thicknesses can be inserted. By providing the outlet opening 30, spark plugs of different lengths and spark plugs with metal sealing rings of different thicknesses can be reliably machined.

Claims

1. Tool for removing a metal seal ring (16) from a spark plug, comprising: - a housing (2) having a receptacle space (3) for the spark plug, wherein the housing (2) has an open longitudinal side (20) on which the receptacle space (3) is exposed and is specified up to insert the spark plug into the receptacle space by way of the open longitudinal side, - a support device (4) which projects into the receptacle space (3) and against which the metal seal ring of the spark plug, when inserted into the receptacle space (3), rests in the axial direction (X-X), - a cutting device (5) which is movable in the axial direction (X-X) of the tool in the receptacle space (3), wherein a gap (8) for receiving the metal seal ring (16) of the spark plug is formed between the cutting device (5) and the support device (4), and - an activation device (6) which can be operated by hand and is operatively connected to the cutting device (5) in order to carry out the axial movement of the cutting device (5) in the receptacle chamber (3) and to move the cutting device (5) in the axial direction (X-X) into the gap (8) in order to cut the metal sealing ring.

2. Tool according to Claim 1, wherein the activation device (6) comprises a lever (60), which is operatively connected to the cutting device (5), wherein the cutting device (5) is movable in the axial direction (X-X) when activating the lever (60).

3. Tool according to one of the preceding claims, wherein the cutting device (5) has a base element (51) on which is disposed at least one blade (50).

4. Tool according to Claim 3, wherein the cutting device (5) has two or three or four or more blades (50).

5. Tool according to Claim 3 or 4, wherein the base element (51) comprises a ring.

6. Tool according to one of Claims 2 to 5, wherein the activation device (6) comprises a first guide element (61) which is connected to the lever (60) in an articulated manner, and a cylinder (63) having a tapered end (63a), wherein the tapered end is in contact with the first guide element (61), and wherein the cylinder is operatively connected to the cutting device (5) in order to carry out the axial movement of the cutting device (5).

7. Tool according to Claim 6, wherein the activation device (6) furthermore comprises a second guide element (62) which is disposed between the cylinder (63) and the cutting device (5).

8. Tool according to one of the preceding claims, furthermore comprising a restoring element (7) for restoring the activation device (6) and the cutting device (5) to an initial state.

9. Tool according to one of the preceding claims, wherein the housing (2) has an exit opening (30) in the axial direction (X-X), from which part of an inserted spark plug can exit.

10. Tool according to one of Claims 2 to 9, wherein the housing (2) has on an external side a recess (21) for receiving the lever (60), and / or wherein the receptacle space (3) has a step so that the receptacle space corresponds substantially to an external contour of the spark plug.