JP2010117031A - Device and method for removing valve seat ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and reliably remove a valve seat ring from a valve seat while causing almost no damage thereon. <P>SOLUTION: For removing the valve seat ring (3) from the valve seat (12) by using a removing device, a removing spindle (7) is inserted into the valve seat ring, and an extension claw (2) is engaged with the valve seat ring and is locked. As axial tensile force is applied on the removing spindle in the removing direction by a hydraulic device (10), the valve seat ring is pulled out from the valve seat in the removing direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a valve seat ring detaching device and a method of detaching a valve seat ring using the detaching device, a detaching spindle for inserting into the valve seat ring, and a detachable spindle that can be engaged with the valve seat ring. The present invention relates to a detaching apparatus having an expansion claw device having a plurality of expansion claws supported on the valve and a method of removing a valve seat ring using the detachment apparatus.

  In particular in the field of large internal combustion engines, such as large diesel and marine diesel, a separate valve seat ring in the valve seat, in particular to ensure better airtightness and to protect the valve and valve seat from wear This valve seat ring is made, for example, of a material having a higher hardness and / or a higher stability against temperature. Such a valve seat ring can be shrunk to the valve seat, for example thermally, i.e. temporarily cooling the valve seat ring and / or heating the valve seat, whereby the valve seat ring is It fixes from the inside with respect to the area | region for fixation in an intake valve or an exhaust valve.

  Such a valve seat ring is used for replacing a worn or damaged valve seat ring and for maintenance work. Can be removed from. For this purpose, a manually operable removal device is known for this purpose. In this removal device, the extension pawl is pivotably supported by the spindle, and the extension pawl is turned outward by screwing the extension cone. Then, this extension claw is pressed against the edge of the valve seat ring. The valve seat ring is then withdrawn from the valve seat together with the extended pawl widened by a removal cone.

  The removal force used in this manual removal process to manually spread the valve seat ring is not large or defined. Furthermore, the engagement of the extended claw that engages with the valve seat ring causes poor engagement, and in particular, there is a risk that the extended claw may tilt in the valve seat ring, which is due to excessive wear of the extended claw and the valve seat ring. Leads to. Furthermore, the torque load of the known removal device is high due to the disadvantageous leverage. In that case, the valve seat ring and the removal device may be damaged.

  The object of the present invention is therefore to allow the valve seat ring to be removed from the valve seat simply, reliably and almost without breakage.

  The object is solved by a device having the features of claim 1 or a method having the features of claim 20. Preferred developments of the invention can be seen from the dependent claims.

  The removal device of the present invention for a valve seat ring is equipped with a removal spindle which can be inserted into the valve seat ring to be removed. This removal spindle is then preferably inserted into the valve seat ring in a direction substantially opposite to the removal direction, which can preferably be arranged parallel to the axis of rotation of the valve seat ring. However, in a preferred embodiment of the invention, the removal device is automatically centered with respect to the valve seat ring so that the removal device can be inserted into the valve seat ring even in an insertion direction inclined with respect to such a rotational axis. can do.

  The removal device according to the invention further comprises an expansion claw device comprising a plurality of expansion claws, which can be engaged particularly positively with the valve seat ring and for this purpose is movably supported on the removal spindle. ing. The extended claw device is then preferably provided with at least two, in particular at least three extended claws.

  In the present invention, the detaching device further includes a hydraulic pressure for applying an axial tensile force in the detaching direction to the detaching spindle and thereby to the valve seat ring via an extension claw supported on the detaching spindle. Equipment is provided. The pulling force for removing the valve seat ring is transmitted by the hydraulic device, not manually, into the spindle, so that a uniform, higher and more defined removal force can be realized, and the removal process It becomes more even and the removal process is simplified. At this time, for example, a stick-slip effect, that is, a force peak generated by alternation of static friction and sliding friction during the detaching process is preferably alleviated by a tensile force applied hydraulically. This makes the process more reliable and less weary.

  According to a preferred embodiment of the invention, the removal spindle is guided in a support in the direction of removal, which support is the periphery of the valve seat ring, i.e. the valve seat or the internal combustion engine in which the valve seat is formed. It is set so as to press against the engine housing. Guiding the removal spindle in the direction of removal prevents the valve seat ring from tilting in the valve seat during removal, thereby reducing wear.

  Preferably, the hydraulic device can be arranged on the support, thereby enabling a structurally simple and / or compact structure of the removal device.

  The hydraulic device may in particular comprise a hollow piston cylinder connected continuously or removably to the removal spindle in order to apply an axial tensile force to the removal spindle. Due to the hollow piston cylinder, the overall height of the removal device can be suitably minimized.

  The hydraulic device can comprise a pump, in particular a high-pressure pump, for generating a hydraulic pressure in order to exert a tensile force on the removal spindle. Thereby, it is possible to easily provide a sufficiently high hydraulic pressure that can be adjusted appropriately and suitably for applying various tensile forces.

  The hydraulic device can include a controller for adjusting a given axial tensile force. Adjustment here means control and adjustment, such as control by setting the voltage applied to the electric motor of the high-pressure pump that generates the hydraulic pressure, and adjustment as eg the axial direction actually applied Applying a given reference tensile force by changing the displacement capacity of the high-pressure pump according to the measured value of the tensile force. The control device can also realize a predetermined axial movement in the removal direction instead of a predetermined tensile force.

  For this purpose, the control device can, for example, measure the movement of the removal spindle in the removal direction and compare it with a reference value. The difference between the reference position of the removal spindle and the actual position can be transmitted as an error signal, for example to a PID controller, which adapts the tensile force applied to the removal spindle accordingly.

  In a preferred embodiment of the present invention, a plurality of expansion pawls of the expansion pawl device are interchangeably mounted on the removal spindle. Thereby, on the one hand, the worn expansion claws can be replaced. On the other hand, by using different extended claw devices with different extended claw profiles, the same removal device can be used for different valve seat rings with different engagement surface profiles with which the extended claw engages. Can do. Similarly, by using extended pawls of different materials, for example, a higher contact force can be achieved for a harder, more rigid valve seat ring compared to a softer, more secure loose valve seat ring. Can also be given.

  The expansion claw of the expansion claw device can be supported on the removal spindle so as to be movable in the radial direction. Unlike known swivelable extension pawls, such radially movable extension pawls remain in a fixed orientation relative to the long axis of the removal spindle, i.e., relative to the long axis of the removal spindle. The valve seat ring is engaged so that the mating surface forms a certain angle. Thereby, poor engagement with the valve seat ring, in particular incomplete engagement, or tilting can be avoided. At the same time, since the expansion pawl is movable in the radial direction, the area engaged with the valve seat ring becomes larger. The extension pawls proceeding radially towards the valve seat ring are preferably suitable for the removal spindle to also be centered radially in the valve seat ring, thereby preventing tilting during removal. Particularly preferably, the extension pawl is supported on the removal spindle in a purely radial movement, so that only a small adjustment is required to engage the removal spindle with the valve seat ring. Similarly, when the expansion pawl moves in the radial direction, it can also move axially with respect to the removal spindle at the same time, for example via a conical guide surface that functions as a forced guide.

  In order to support the movement in the radial direction, the expansion claw of the expansion claw device may be pressed against the radial guide surface of the removal spindle extending radially outward from the removal spindle in an axial direction opposite to the removal direction. it can. Within this radial guide surface, the extension pawl can preferably slide in the guide groove, thereby facilitating handling of the removal device.

  Preferably, the expansion pawl of the expansion pawl device can be fixed in a radial direction at an engagement position where the expansion pawl engages the valve seat ring. This can be done, for example, with a self-locking screw that prevents the extension pawl from moving radially toward the removal spindle by friction. Similarly, such fixation can be achieved by a snap connection or the like.

  In order to move the expansion pawl in the radial direction and engage the valve seat ring, in one preferred embodiment of the present invention, the detaching device is mounted on the detaching spindle so that it is supported on the detaching spindle in an axially movable manner. A surface is provided, and the guide surface cooperates with a mating surface provided obliquely on the extension claw of the extension claw device. At this time, the oblique guide surface and the mating surface form one forced guide, and the axial movement of the oblique guide surface is converted into the radial movement of the extension claw by the forced guide. In this way, the expansion pawl can be easily engaged with the valve seat ring.

  At this time, the radial distance between the oblique guide surface and the removal spindle can be increased or decreased as it advances in the removal direction. When the distance increases, the oblique guide surface moves in the opposite direction to the removal direction, that is, by moving from the outside toward the extension claw, whereby the extension claw is directed outward in the radial direction. In this case, the overall height in the removal direction can be suitably shortened. On the other hand, when the radial distance is reduced in the removal direction, the extension pawl slides outward in the radial direction by moving the oblique guide surface in the removal direction. In this case, the mounting space located on the opposite side of the valve seat ring from the direction of removal can be suitably used.

  In one preferred embodiment of the invention, the oblique guide surface is formed in a threaded cone that is movable along the axial direction of the removal spindle. This threaded cone engages with the removal spindle via a moving thread, and when rotated, the threaded cone moves axially on the removal spindle guided in the axial direction. Move it toward. If the moving sled is self-locking, the expansion pawl can be securely fixed in the valve seat ring by appropriately setting the threaded sleeve on the external thread of the threaded cone.

  In addition to or instead of guiding the extension pawl in the radial direction on the radial guide surface, the extension pawl can also be guided and supported on the oblique guide surface.

  In particular, the expansion pawl is designed to minimize the starting diameter of the expansion pawl during insertion of the removal device and to automatically disengage the valve seat ring after the force of pushing the expansion pawl radially outwards is lost. The extension claw of the claw device can be pretensioned toward the removal spindle by elastic means. Such elastic means includes, for example, an O-ring disposed on the outer periphery of the expansion pawl device, and this O-ring is elastically extended when the expansion pawl is engaged with the valve seat ring. Thus, the expansion pawl device thereby attempts to return to a position where the expansion pawl device can be inserted into the valve seat ring.

  The support set to be pressed against the periphery of the valve seat ring can be removably arranged on the periphery, in particular it can be positively attached to the periphery and / or screwed to the periphery. it can. For this purpose, the support preferably has a support surface adapted to the periphery of the valve seat ring, i.e. the valve seat or the housing in which the valve seat is formed.

  Like the gate, the support portion is provided with a crossbar transverse to the axial guide of the removal spindle, and this crossbar is set to be pressed against the periphery of the valve seat ring by a plurality of support pillars. This creates an advantageous force flow and a lightweight and compact structure. A hydraulic device can be preferably arranged on the cross.

  To remove the valve seat ring using the removal device of the present invention, the removal spindle is first inserted into the valve seat ring, and then the expansion pawl of the expansion pawl device is engaged with the valve seat ring.

  The expansion pawl of the expansion pawl device can be securely fixed to the removal spindle after being engaged with the valve seat ring. Thereby, the expansion pawl device can be held on the valve seat ring without play during the detaching process, thereby reducing wear.

  Next, an axial tensile force is hydraulically applied to the removal spindle. This tensile force acts on the valve seat ring via the extension claw, and the valve seat ring is pulled out from the valve seat in the direction of removal.

  The axial tensile force can then be increased gradually, i.e. stepwise or continuously, until the valve seat ring is disengaged from the valve seat. Since the holding friction holding the valve seat ring to the valve seat is greater than the sliding friction in the relative movement between the valve seat ring and the valve seat, in order to prevent the valve seat ring from being pulled out too quickly, The tensile force can be reduced.

  In particular, the axial tensile force exerted by the hydraulic unit can be adjusted so as to set the removal action and / or a predetermined course of the tensile force. For example, when the valve seat ring is pulled out from the valve seat at a constant speed, the above-mentioned adjustment first increases the tensile force until the tensile force exceeds the holding frictional force holding the valve seat ring on the valve seat. During the transition from holding friction to sliding friction, the tensile force is pulled down by adjustment, and as soon as the valve seat ring is completely pulled out of the valve seat, the tensile force becomes zero. At this time, if the holding friction is generated again for a short time during the detaching process, the tensile force is correspondingly increased by the adjustment, and the valve seat ring is moved again.

  Further advantages and features of the invention can be understood from the dependent claims and the embodiments described below, with reference to a partly schematic view.

FIG. 3 is a perspective view of a portion of a removal device according to one embodiment of the present invention. FIG. 2 is a view of the removal device of FIG. 1 cooperating with a valve seat ring of an internal combustion engine. FIG. 2 is a view of the removal device of FIG. 1 cooperating with a valve seat ring of an internal combustion engine. 2. The detaching device of FIG. 2 set in the valve seat of the internal combustion engine in the left or right divided section, in which the right half is expanded before the expansion pawl is engaged with the valve seat ring, and the left half is expanded. It is the figure represented after a nail | claw engaged with the valve seat ring. FIG. 4 is a top view of an extension claw of the detaching device of FIG. 3 arranged in a valve seat ring.

  FIG. 1 is a perspective view of a removal spindle 7 of a removal device according to one embodiment of the present invention, and this removal device is provided with three extended claws 2 that are movably supported. Can be moved radially outward by a screw cone 4. The threaded sleeve 5 has a blocking function, that is, a function of fixing the expansion claw 2 when the threaded sleeve 5 is screwed on the removal spindle 7 toward the expansion claw 2. Details will be described with reference to FIG.

  The right part of FIG. 3 shows the valve seat ring 3 fixed by friction by applying a pretension inside the valve seat 12 of the intake valve of the internal combustion engine. This valve seat ring can be similarly arranged on the exhaust valve.

  In one embodiment of the invention, the removal device is set on the valve seat. For this purpose, as shown in the right part of FIG. 3, the gate-shaped support 9 is from the outside, that is, in the direction opposite to the removal direction (from top to bottom in FIG. 3). A removal spindle 7 which is positively set in the housing 8 and is supported so as to be axially movable in the support 9 is inserted into the valve seat ring 3.

  A guide piece 1 is fixed to the rear end of the removal spindle 7 in the removal direction so as to be prevented from being twisted, and the front surface in the removal direction of the guide piece 1 has a radial guide surface for the three extension claws 2. The extension pawl 2 is supported on the front surface, preferably in a guide groove so as to be movable in the radial direction. The inner circumference of the front surface of the extended claw 2 opposite to the guide piece 1 is an oblique mating surface, and is formed on the mating surface on the rear front surface in the removal direction of the screw cone 4. The inclined guide surfaces are combined, and the extension claw 2 is moved by the guide surfaces. The screw cone 4 is rotatably attached to the tap spindle or the removal spindle 7, that is, is attached to the removal spindle 7 so as to be movable in the axial direction, and an external screw is provided on the outer periphery of the screw cone 4. The screw meshes with the inner screw of the threaded sleeve 5. By rotating the removal spindle 7, the screw cone 4 can be moved in the axial direction toward the mating surface of the extension claw 2 in the direction opposite to the removal direction. At this time, the extension claw 2 is pushed outward in the radial direction. It is. For this purpose, the extension pawl 2 is slidably guided in a radial guide groove in the radial guide surface of the guide piece 1 (not shown).

  The extension claw 2 can be fixed to the guide piece 1 by rotating the threaded sleeve 5 on the screw cone 4.

  The front end of the removal spindle 7 in the removal direction is connected to a cylinder of a hydraulic hollow piston cylinder 10, and this hydraulic hollow piston cylinder 10 is disposed on a cross of the gate-like support portion 9 and is hydraulically operated. In the removal direction, the axial tensile force can be removed and applied to the spindle 7. For this purpose, the hydraulic hollow piston cylinder 10 is connected to a high-pressure pump (not shown) via a hydraulic connection part 11 (FIG. 2), and the high-pressure pump controls the displacement amount in the hydraulic hollow piston cylinder 10. Hydraulic pressure can be generated.

  Since the extension claw 2 is pretensioned radially inward toward the removal spindle 7 via the O-ring 13, even if no axial force is applied to the extension claw 2 by the screwed cone 4. The extension claw 2 does not jump out of the guide piece 1 in the radial direction.

  In order to remove the valve seat ring 3, first, as shown in the right part of FIG. 3, the support portion 9 is connected to the internal combustion engine so that the removal spindle 7 with the guide piece 1 is inserted into the valve seat ring 3. The housing 8 is set. That is, in the right part of the figure, the detaching device is in the mounted state, the expansion pawl 2 is squeezed with the aid of the O-ring 13, and the screwing cone 4 and the threaded sleeve 5 are unscrewed. At this time, the extension claw 2 is reliably present at the inserted position by the O-ring 13 so as not to jump out beyond the outer periphery of the guide piece 1.

  At this time, the dimensions of the support pillars supporting the rungs of the support portion 9 are such that when the support portion 9 is positively set in the housing of the internal combustion engine, the flange-shaped protruding portion of the expansion pawl 2 is It is dimensioned to face the radial groove between 12 and the valve seat ring 3.

  Next, as shown in the left part of FIG. 3, the screwing cone 4 is rotated, so that the screwing cone 4 is directed toward the extension claw 2 in the direction opposite to the removing direction in the axial direction of the removing spindle 7. Moving. At this time, the oblique guide surface on the front surface of the screw cone 4 that slides on the oblique fitting surface of the extended claw 2 moves the extended claw 2 guided in the radial direction outward in the radial direction. The flange-like protrusion fits into a groove between the valve seat 12 and the valve seat ring 3. At this time, the flange-like protrusion is pressed against the rear edge of the valve seat ring 3 in the removing direction, while the recess of the extension claw 2 adjacent to the flange is connected to the inner circle of the valve seat ring 3. Fits positively around the lap. As a result, the entire removal device is accurately centered in the valve seat ring 3. That is, in the left part of FIG. 3, the extension claw 2 is engaged, and the extension claw 2 is positively locked by the threaded sleeve 5.

  By further tightening the threaded sleeve 5, the expansion pawl 2 is firmly fixed, so that the expansion pawl 2 is fixed in a self-locking manner at the radial position. For this purpose, the threaded sleeve 5 is provided with a rotating pin hole 6 so that a sufficiently large rotational torque can be applied to the threaded sleeve 5.

  The high-pressure pump is then manually or hand-powered, or in some cases using compressed air, or in the preferred embodiment the actual axial position of the removal spindle 7 relative to the support 9 and over time. Operation is performed with the displacement controlled by comparing with a reference position that moves linearly in the removal direction. The difference in the axial direction between the actual position and the reference position is transmitted as an error signal to the PID control device of the high-pressure pump.

  At the beginning of the removal process, the valve seat ring 3 remains in the valve seat 12 due to the large holding friction. Accordingly, the error signal also increases, so the control device increases the hydraulic pressure supplied to the hydraulic hollow piston cylinder 10 from the high-pressure pump. Accordingly, the axial tensile force applied to the removal spindle 7 by the hydraulic hollow piston cylinder 10 and consequently to the valve seat ring 3 via the expansion pawl 2 is increased.

  At the same time as the tensile force exceeds the holding friction force, the valve seat ring 3 is displaced from the valve seat 12 in the axial direction and accelerated in the removal direction. Accordingly, the reference position in the axial direction of the removal spindle 7 that pulls out the valve seat ring 3 approaches the actual position, so that the error signal becomes small, and then the hydraulic pressure supplied to the hydraulic hollow piston cylinder 10 by the control device. The pressure is lowered. This results in a suitably uniform removal process as shown in the continuous view from FIG. 2A to FIG. 2B.

  When the valve seat ring 3 is completely removed from the valve seat (FIG. 2B), the reference position of the removal spindle 7 with respect to the support portion 9 becomes constant, so that the hydraulic pressure from the high pressure pump to the hydraulic hollow piston cylinder 10 is increased. Will not be sent. Next, since the expansion claw 2 is pulled back to the start position of the expansion claw 2 inside the guide piece 1 by the elastic deformation return of the O-ring 13, the removal device should be lifted from the housing 8 of the internal combustion engine. The valve seat ring 3 can be pulled out.

DESCRIPTION OF SYMBOLS 1 Guide piece 2 Expansion nail 3 Valve seat ring 4 Screwed cone 5 Threaded sleeve 6 Rotating pin hole 7 Removal spindle 8 Housing 9 Support part 10 Hydraulic hollow piston cylinder 11 Hydraulic connection part 12 Valve seat 13 O-ring

Claims (23)

A device for removing the valve seat ring (3),
One removal spindle (7) for insertion into the valve seat ring;
One extension pawl device comprising at least two, preferably three extension pawls (2), engageable with the valve seat ring and movably supported on the removal spindle;
One hydraulic device (10) for applying an axial tensile force to the removal spindle in the removal direction;
A removal device comprising:   2. Removal according to claim 1, characterized in that the removal spindle is guided in the removal direction by a support part (9) set to be pressed against the periphery (8) of the valve seat ring. apparatus.   The detachment device according to claim 2, wherein the hydraulic device is disposed on the support portion.   The hydraulic device comprises a hollow piston cylinder (10) connectable to the removal spindle for applying a tensile force to the removal spindle. The removal device described.   The removal device according to any one of claims 1 to 4, wherein the hydraulic device includes a high-pressure pump for generating a hydraulic pressure that applies an axial tensile force to the removal spindle. .   6. The hydraulic device according to any one of claims 1 to 5, characterized in that the hydraulic device comprises a control device for adjusting a given axial tensile force or axial movement in the removal direction. Removal device.   The removal device according to any one of claims 1 to 6, wherein the expansion claw of the expansion claw device is exchangeably supported by the removal spindle.   The removal device according to any one of claims 1 to 7, wherein the expansion claw of the expansion claw device is supported by the removal spindle so as to be movable in a radial direction.   The extension claw of the extension claw device is pressed against the radial guide surface of the removal spindle in an axial direction opposite to the removal direction, and is attached to the removal spindle using one threaded sleeve (5). 9. Removal device according to claim 8, characterized in that it is lockable.   The removal device according to claim 9, wherein the expansion claw of the expansion claw device is supported by being guided in a guide groove of the radial guide surface.   The removal device according to any one of claims 8 to 10, wherein the expansion claw of the expansion claw device is fixable in a radial direction at an engagement position.   The removal spindle is provided with an oblique guide surface that is movable in the axial direction, and the guide surface cooperates with an oblique alignment surface of the expansion claw of the expansion claw device to cause the expansion claw to move the expansion claw. The removal device according to any one of claims 8 to 11, wherein the removal device is moved away from the removal spindle in the radial direction.   The removal device according to claim 12, characterized in that a radial distance between the oblique guide surface and the removal spindle increases in the removal direction.   The oblique guide surface is formed on a screw cone (4), the screw cone (4) being supported by the removal spindle (7) so that it can rotate, that is to say on the removal spindle (7) movably in the axial direction. The removal device according to any one of claims 12 to 13, wherein the removal device is provided.   The removal device according to any one of claims 12 to 14, wherein the expansion claw of the expansion claw device is guided and supported in a guide groove of the oblique guide surface.   Detachment according to any one of claims 8 to 15, characterized in that the extension pawl of the extension pawl device is pretensioned towards the removal spindle by elastic means (13). apparatus.   The extension claw of the extension claw device includes one or a plurality of protrusions and / or recesses that can be engaged with recesses, edges, or protrusions on the inner circumferential surface of the valve seat ring. The detaching device according to any one of claims 1 to 16.   The detachment device according to any one of claims 2 to 17, wherein the support portion set in the peripheral portion of the valve seat ring can be detachably disposed on the peripheral portion.   The support portion has a gate-like crossbar for guiding the removal spindle in the axial direction, and the crosspiece is supported on the peripheral portion of the valve seat ring via a support column in a direction opposite to the removal direction. 19. Removal device according to any one of claims 2 to 18, characterized in that it is set to be pressed and / or the hydraulic device is arranged on the rung. A method for removing a valve seat ring (3) using the removal device according to any one of claims 1 to 19,
-Inserting said removal spindle (7) into said valve seat ring;
-Engaging the expansion pawl (2) of the expansion pawl device with the valve seat ring;
Applying an axial tensile force in the removal direction to the removal spindle by the hydraulic device (10) so that the valve seat ring is pulled out of the valve seat (12) in the removal direction;
A method characterized by comprising:   21. A method according to claim 20, characterized in that the axial pulling force is gradually or continuously increased until the valve seat ring is disengaged from its periphery.   After the expansion pawl of the expansion pawl device is engaged with the valve seat ring, the expansion pawl of the expansion pawl device is firmly fixed to the removal spindle by a threaded sleeve (5). The method according to claim 20 or 21, wherein:   23. The axial force exerted by the hydraulic device is adjusted so that the removal movement and / or the tensile force follows a predetermined course. The method described.

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