JPH028869B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a piston ring tightening device for mounting a piston ring on a piston, and has two expansion jaws, each of which tightens the piston ring. In order to spread the piston ring, in the area of the ring abutment, the piston ring rests against the ring end by means of a gripping hook and is gripped from behind on the inside, and then moved away from the ring end to the outside of the piston ring. is supported perpendicularly to the tangent of the piston ring, and further includes a deflection device for the expansion jaw, a portion of the deflection device engaging the expansion jaw and preventing the expansion of the piston ring. At times, the invention relates to a type in which the expanding jaw cooperates with the pivoting of the piston ring about a predetermined pivot point so that the circumferential deflection of the end of the piston ring overlaps with the pivoting of the piston ring about a predetermined pivot point.

Increasing power output in internal combustion engines and, above all, increased ignition pressures require piston rings that must exert a higher uniform compression on the shilling bush than piston rings of conventional construction. Highly demanding piston rings have a diameter smaller than the radial ring width and are designed to be rigid. The material of the piston ring generally aims at advantageous running properties and does not have a distinct elasticity limit or a constant elastic modulus.
Furthermore, most piston rings close to the combustion chamber have strong running rails with a modulus of elasticity completely separate from the base material, which running rails are brittle and easily damaged. The shape of such a piston ring is approximately apple-shaped when not installed, and in this case, the radius of curvature of the ring area on the opposite side from the ring abutting area is larger than the radius of curvature of the ring area toward the respective ring abutting area. . Furthermore, near the ring abutment there is still a free grinding, a step or the like for a ring-shaped contour.

In order to eliminate or reduce to a minimum the deformation of the piston ring during the expansion of the piston ring and during the installation of the piston ring on the piston, the tension on the piston ring is created as evenly distributed as possible during this phase, and the ring abutment area is Make sure to protect the end of the ring towards the end. Most currently known piston ring scissors or piston ring expansion devices do not meet these requirements at all or only partially. In the case of the piston ring expansion device according to GB 682,976, this requirement can be met, but such a known device is provided with a very expensive four-link drive.
The exact dimensions and manufacture of the four-link drive requires significant cost.

It is an object of the invention to consist of only a few parts, which are simple and inexpensive to manufacture, and which can also be easily adapted to piston rings of different sizes and which, when installing the piston ring, have a ring area which is directed towards the ring abutment. It is an object of the present invention to provide a piston ring tightening device capable of tightening the piston rings as uniformly as possible while protecting the piston rings.

In order to solve such problems, the present invention
The two expansion jaws each have a first guide element and a second guide element, and the expansion jaws are caused by the first guide elements to
The guide rail is supported by an arcuately curved inner sliding surface of the guide rail, and the guide rail is supported by the second guide member with an outer sliding surface parallel to the inner sliding surface. , the guide rail passes between the guide members of both expansion jaws, and the sides of both sliding surfaces are arranged so that both expansion jaws expand the piston ring beyond the diameter dimension of the piston. the guide rail protrudes from the expansion jaw by an amount that is guided along the sliding surface, and the inner sliding surface of the guide rail has a curvature with a radius, the poles of the curvature are:
The center point of the piston ring to be expanded is shifted from the center point of the piston ring by 0.05 to 0.30 times the piston nominal diameter on the line of symmetry toward the ring range on the opposite side of the ring abutting portion. Further advantageous embodiments and refinements of the invention are set out in the dependent claims.

The advantages of the piston ring tightening device of the present invention will be described in detail below. When using the tightening device according to the invention, the piston rings are protected on both sides of the ring abutment by a gradually increasing tightening over a largely modified wide range of up to approximately 60 degrees, as well as a lower The pressing force provides excellent protection for the running surfaces that are often coated. In the remaining ring area, the uniform constant tightening prevents plastic deformation of the piston ring or, in the case of rigid piston rings, is evenly distributed over the entire area and limited to a minimum.
According to the present invention, the local maximum tightening in the vicinity of the abutment part in the area diametrically opposite to the ring abutment part or in the shape modification area where there is a risk of almost ring deformation in the case of conventional piston ring gripping devices is achieved by the present invention. This does not occur if a tightening device is used. This advantage is due to the fact that, apart from the various parts for expanding piston rings of different sizes, the piston consists of three components, namely both expansion jaws and a guide rail, which are simple and inexpensive to manufacture. Realized by a ring tightening device. If the guide rail is designed accordingly, it is furthermore advantageous to clamp piston rings of different sizes with the aid of its clamping device, in order to achieve as uniform a tightening course as possible without abandoning the given requirements. enable.

The invention will be explained below with reference to the exemplary embodiments shown.

In the drawings, identical or mutually corresponding components are provided with the same reference numerals.

In the drawing, reference numeral 1 designates a piston ring, in particular for pistons of large internal combustion engines, and reference numeral 2 designates the entire piston ring tightening device according to the invention for tensioning piston rings on the aforementioned pistons. The piston ring tightening device 2 has two expansion jaws 3, 4,
Each of the expansion jaws is connected to the ring end 5 by means of a pawl hook 7 or 8 in order to expand the piston ring 1 in the area of the piston ring abutment.
Or, contact 6 and grab the inside from the rear.
Furthermore, each expansion jaw 3 or 4 has an abutment surface 9 or 10, by means of which the expansion jaw is separated from the ring end 5 or 6 so that the piston ring 1 to be tightened can be tightened. It is usually supported on the outside of the cylinder perpendicular to the tangent to the piston ring. Furthermore, the piston ring tightening device 2 has a deflection device for the expansion jaws 3, 4, generally and generally indicated in the drawing by the reference numeral 11, which deflection device 11 is partially expanded. The piston ring 1 is connected to or fixed to the jaw and is connected to the expanding jaw as follows: piston ring 1
When the piston ring is expanded, the pivoting of the piston ring about a predetermined pivot point cooperates with the deflection from the piston ring end 5 or 6 in the circumferential direction. Further, the function of the piston ring tightening device according to the present invention will be explained with reference to FIGS. 5 to 8.

The expansion jaws 3, 4 are likewise constructed and arranged mirror-symmetrically below the piston ring tightening device 2.

According to the invention, each expansion jaw 3 or 4 has a first guide element 12 or 13, which guides the expansion jaw on the arc-curved inner sliding surface of the guide rail 15. 14 and a second guide member 16
or 17 is supported on an outer sliding surface 18 parallel to the inner sliding surface of the guide rail 15.
The guide rail 15 passes through both expansion jaws 3, 4 and the sliding surfaces 14, 18 laterally extend the expansion jaws.
The two expansion jaws 3, 4 project beyond the diameter of the piston for expansion of the piston rings and are guided along guide rails. The inner sliding surface 14 of the guide rail 15 has a curvature with a radius R _F , and the pole P of this curvature is located from the center point M of the piston ring 1 to be tightened, as shown in FIGS. 6 and 8. , the nominal diameter of the piston ring 1
It is located offset by a factor of 0.05 to 0.30 on the line of symmetry of the piston ring towards the ring region opposite the ring abutment.

The radius R _F of the inner sliding surface 14 of the guide rail 15 is
Starting from the pole P, it has a length approximately 0.55 to 0.80 times the nominal diameter of the piston ring 1 to be tightened.
As a result, the distance between the guide rail 15 and the abutment of the piston ring 1 to be tightened is precisely defined.

In the case of the exemplary embodiment, i.e. in the case of a piston ring 1 to be tightened with a nominal diameter of 520 mm, the pole P has a distance from the center point M of the piston ring that is 0.171 times the nominal diameter. The radius of curvature R _F of the inner sliding surface 14 of the guide rail 15 is
Starting from the pole P, it has a length corresponding to 0.677 times the nominal diameter of the piston ring 1. 6th
As shown in the figure, in the exemplary embodiment the two points G, H at which the abutment surfaces 9, 10 of the two expansion jaws 3, 4 rest on the outside of the piston ring 1 are located at In the operating state, it has a linear spacing corresponding to 0.75 times the nominal piston ring diameter. However, the distance between these points G and H can be larger or smaller in other embodiments and is approximately 0.5 to 0.9 times the nominal diameter of the piston ring 1 to be tightened.

In the embodiment according to FIGS. 1, 3 and 4, the two expansion jaws 3, 4 of the piston ring tensioning device 2 each have two plane-parallel plates 19, as shown in FIG. 20, the plates 19, 20 cover the guide rail 15 from above and below in the transversely extending plane, and there is a slight play between the plates and the guide rail, and the piston When using the ring tightening device, the piston ring to be tightened is at least partially covered from above and below. This state is shown in Figure 1.
As can be seen from FIGS. 3 and 4, the sides of the piston ring are covered by both plates 19 and 20, respectively.
The start and end ranges of Furthermore, as can be seen in FIG. 2, both plates 19, 20 receive between them a gripping hook 7 or 8 in the respective starting region assigned to the ring abutment, which gripping hook is connected to the plate. It is materially bonded and at the same time forms a spacer for the plate. Furthermore, the two plates 19, 20 are connected indirectly or directly to a part of the deflection device 11 for actuation of the two expansion jaws 3, 4. This will be explained further later.

As can be seen from FIGS. 1, 3 and 4, the guide member 12 of the respective expansion jaw 3 or 4
Alternatively, 13 is formed by a sliding shoe which forms a spacer for the two plates 19, 20 of the expansion jaw 3 or 4, and on the outside the piston ring 1 to be tightened.
a contact surface 9 or 10 for the guide rail 15;
1 or 22. The sliding shoe may be fixed or removable by screws.
Each expansion jaw 3 or 4 is connected to both parallel plates 19, 20. Instead of a sliding shoe, the first guide member 12 or 13 can also be formed by a wall, which wall is arranged between the plates 19, 20 in the same way as a sliding shoe. The second guide member 16 or 17 of the expansion jaw 3 or 4 is formed by a roller or a bolt in the illustrated embodiment;
The roller or bolt is parallel to both plates 1
It is rotatably supported between 9 and 20 and abuts against the outer sliding surface 18 of the guide rail 15.

Moreover, instead of rollers or bolts, the second guide element 16 or 17 of the respective expansion jaw 3 or 4 can also be formed by a sliding shoe or a wall, which sliding shoe or wall is connected to the first guiding member. It is designed similarly to part 12 or 13 and is arranged on both plates 19,20.

A travel-limiting pin 23 or 24 is arranged on the guide rail, which travel-limiting pin is connected to the corresponding stop surface 2 of the expansion jaw 3 or 4 in order to limit the expansion stroke of the piston ring tensioning device 2.
Work with 5 or 26. In yet another embodiment, the travel limiting pins 23, 24 are
Alternatively, it is also possible for the guide rail 15 to be provided with the stop surfaces 25, 26 on the guide rail 15. Stopper surface 25 or 26
is integrally molded on the outside of one of the plates 19 or 20, as shown in FIGS. 1 and 3,
Alternatively, as shown in FIG. 4, one or both plates 19, 20 of the expansion jaw 3 or
It is provided in a long hole that is integrally molded into the. Such slots also serve to reduce the weight of the piston ring tightening device 2.

In an advantageous embodiment, the inner and/or outer sliding surfaces 14, 18 of the guide rail 15 are provided with recesses 3.
7, 38 (FIG. 4) or a flat surface 39 (FIGS. 1 and 3), which have the following spatial features, that is, have a slight play and are thereby In the starting position of the piston ring tightening device 2, the two expansion jaws 3 or 4 are offset relative to the guide rail 15, and this ensures a force-free engagement of the piston ring 1 to be tightened in the device. It is arranged as shown.

As shown in FIG. 1, when the piston ring tightening device 2 of the invention is used for tightening small piston rings with a nominal diameter of up to approximately 300 mm, the deflection device 11 is connected to two hand levers 2.
7 or 28, which hand levers are rigidly integrated in material or releasably connected to the expansion jaws 3 or 4, respectively, or are formed on the expansion jaws. Furthermore, a return spring 29 is provided, which is clamped between the mutually opposite ends of the two expansion jaws 3, 4 and is capable of returning the expansion jaws from the deflection position to the basic position. . When using the piston ring tightening device 2 according to the invention for tightening medium-sized piston rings with a nominal diameter of up to approximately 600 mm, the deflection device 11 for the expansion jaws 3, 4 is arranged as shown in FIG. As shown, it consists of two hand levers 30 or 31 bent at an obtuse angle, and these hand levers are rotatably connected to the expansion jaws 3 or 4 via bearings, respectively. A bolt, which rotatably supports a guide element 16 or 17 in the form of a roller, serves as a bearing for the hand lever 30 or 31. Both hand levers 30,3
1 are rotatably coupled to each other via a hinge 32. That is, the expansion jaws 3, 4 are coupled in such a way that they can be deflected from their starting position by pulling the rear end of the hand lever in the direction corresponding to the arrow shown in FIG. Spring 33 tightened between both hand levers 30, 31
serves for the return guidance from the deflection device and thus for the return guidance of the expansion jaws 3, 4 from the deflection device to the starting position.

Piston ring tightening device 2 for tightening large piston rings with a nominal diameter of 600 mm or more
When using both expansion jaws 3 and 4
A deflection device 11 extending between and connected to the expansion jaw is provided, which deflection device can be operated mechanically, hydraulically or pneumatically. It has a booster such as a threaded spindle, a transmission, a stroke cylinder or the like. In FIG. 4, the deflection device 11 consists, for example, of a pressure piston 34 connected to the expansion jaw 3 and a pressure cylinder 35 connected to the expansion jaw 4, the pressure cylinders comprising both For deflection of the expansion jaws 3, 4, they are loaded or unloaded by a hydraulic or pneumatic pressure medium via a connection piece 36 of a pressure source (not shown).

The theoretical basis of the piston ring tightening device according to the invention will be explained below with reference to FIGS. 5 to 8.

FIG. 5 shows the shape of the piston ring 1 in the untightened state, which is shown schematically and slightly exaggerated in the lower part for better clarity. In this case, the piston ring 1 has a substantially apple-shaped shape, and the portion of the piston ring facing the ring abutting portion in the relaxed state is clearly defined by the radius of curvature r _M of the portion facing the ring abutting portion. Large radius of curvature
It has R _M.

The neutral line of the piston ring 1, shown schematically in FIG. 6, is designated by 40. In the left half of the drawing, this piston ring 1 is schematically assigned one half of a piston ring tightening device 2 according to the invention, whereas from the right half of the drawing a piston ring tightening device 2 according to the invention is assigned. The tightening distribution in the piston ring 1 during use is obvious. Inside the piston ring tightening device 2 according to the invention, the piston ring 1 is stressed by two forces F _I and F on both sides of the ring abutment (see FIG. 5). The force F _I is directed perpendicularly to the tangent at the point G or H at which the respective expansion jaw 3 or 4 abuts the piston ring 1 from the outside and is directed into the interior of the piston ring 1. . The force F acts parallel but in an opposite direction to the force F _I and acts on the inner edge of the respective ring end 5 or 6. In this case, as shown in FIG. 5, the force F is a first force component F _U acting in the circumferential direction of the piston ring 1 starting from the respective ring end 5 or 6 and spreading the piston ring. and a second force component F _R acting at right angles to the first force component at the same point on the piston ring 1 as the ring end. The second force component F _R is applied during the expansion of the piston ring in the range between points A and B on one side and between points C and D on the other side, i.e. for each expansion jaw 3 or 4. creates a bending moment that increases from point A to point B or from point C to point D within the range A-B or C-D.
Remarkably constant bending moment outside of
It gives rise to M _B =・F _R =・_FR .

FIG _. 7 shows _the deformation of _the piston ring 1 starting from the relaxed configuration shown in FIG _. The line shows the piston ring 1 in its starting position, and the outer line with points A ₂ , B ₂ and C ₂ , D ₂ shows the expanded end state of the piston ring 1 . Furthermore, FIG. 8 shows the changes in shape and position that the piston ring undergoes when it is unfolded inside the piston ring tightening device 2 according to the invention.

When expanding piston ring 1, point A ₁
goes to point A ₂ , point B ₂ goes to point B ₂ , point C ₁ goes to point C ₂ , point D ₁
moves to point D ₂ . From a kinematic perspective, the movement course when the piston ring 1 is expanded by the piston ring tightening device 2 according to the invention is from point A ₂ or A ₃ to point A ₂ or B ₂ or Points of ring segment A-B or C-D with superimposed turns from points C ₂ and D ₃ to points C ₂ and D ₂ with point C as the center
It is regarded as a translational movement from A ₁ , B ₁ to points A ₂ , B ₃ or from points C ₁ , D ₁ to points C ₂ , D ₃ . This movement profile results in the desired constant tightening profile of the piston ring 1, which is shown in the right half of FIG. This constant tensioning course is obtained in that the expansion jaws 3 or 4 are precisely guided along a guide rail 15, the inner sliding surface 14 of which forms a relative trajectory for the movement course. do. Inside the piston ring tightening device 2, the following movement sequence takes place in FIG. That is, points A and C are already defined pole P and radius
Point A ₁ on the circular orbit indicated by the broken line defined by R _A/C
to point A ₂ ′ or from point C ₁ to point C ₂ ′, and points B and D also move from point B ₁ on a circular orbit defined by pole P and radius _B/D, also indicated by the dashed line. point
Move to B ₂ ′ or from point D ₁ to point D ₂ ′. In this case, the piston ring 1 is spatially displaced, and the point E (Fig. 7) located diametrically opposite to the ring abutment is moved from the point E ₁ shown in Fig. 8 to the point E ₂ . Move.

The piston ring tightening device 2 according to the invention, which allows such a movement course, has already been described by means of three embodiments shown in FIGS. 1 to 4. FIG. The configuration shown here can also be implemented in other ways, inter alia with respect to the shape, dimensions, manufacture and material of the expansion jaws 3, 4. Instead of a welded or soldered construction, the expansion jaw can also be formed as a one-piece cast part. Guide rail 15
is made of a material, such as steel, which ensures bending strength.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a first embodiment of a piston ring tightening device according to the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. FIG. 4 is a plan view showing a third embodiment of the piston ring tightening device of the present invention, FIG. 5 is a schematic diagram showing the piston ring in an untightened state, and FIG. 6 is a plan view showing the second embodiment. The left half shows a schematic diagram of a piston ring tightening device according to the invention, the right half shows a schematic diagram showing the progress of tightening a piston ring when using this piston ring tightening device, and FIG. FIG. 8 is a schematic diagram illustrating the deformation of a piston ring during expansion in a piston ring tightening device according to the invention; FIG. 1... Piston ring, 2... Piston ring tightening device, 3, 4... Expansion jaw, 5, 6... Ring end, 7, 8... Pawl hook, 9, 10...
Contact surface, 11... Direction change device, 12, 13... Guide member, 14... Inner sliding surface, 15... Guide rail, 16, 17... Guide member, 18... Outer sliding surface, 19, 20 ... Plate, 21, 22 ... Sliding surface, 23, 24 ... Stroke limit pin, 25, 26
...Stopper surface, 27, 28...Hand lever,
29... Return spring, 30, 31... Hand lever, 32... Hinge, 33... Spring, 34... Pressure piston, 35... Pressure cylinder, 36... Connection tube piece, 37, 38... Notch part, 39...plane part, 40...neutral line.

Claims (1)

[Scope of Claims] 1. A piston ring tightening device for mounting a piston ring on a piston, which has two expansion jaws, each of which has the following features:
In order to expand the piston ring, the piston ring is gripped in the area of the ring abutment by a hook that is in contact with the ring end, and is gripped from the rear on the inside, and is further moved away from the ring end and pushed to the outside of the piston ring. The piston ring is supported perpendicularly to a tangent to the piston ring, and further includes a deflection device for the expansion jaw, a portion of the deflection device engaging the expansion jaw and displacing the piston ring. The expansion jaw cooperates with the expansion jaw so that the rotation of the piston ring about a predetermined rotation point is superimposed on the circumferential displacement of the end of the piston ring when the expansion jaw is expanded. The two expansion jaws 3, 4 each have one first guide member 12,
13 and one second guide member 16,1 respectively
7, the expansion jaw is supported by the first guide member on the arcuately curved inner sliding surface 14 of the guide rail 15, and the second guide member 16, 17, guide rail 15
is an outer sliding surface 18 parallel to the inner sliding surface.
The guide rail 15 is supported by the guide members 12, 13; 16,
17, and both sliding surfaces 14,1
The sides of 8 protrude from the expansion jaws to such an extent that the two expansion jaws 3, 4 are guided along the sliding surfaces in order to expand the piston rings beyond the diameter dimension of the piston, and the said guide rails The inner sliding surface 14 of 15 has a curvature with a radius R _F , and the pole P of the curvature extends from 0.05 to approximately the nominal piston ring diameter from the center point M of the piston ring 1 to be expanded.
A piston ring tightening device for mounting a piston ring on a piston, characterized in that the piston ring is shifted by 0.30 times on a line of symmetry toward a ring range on the opposite side of a ring abutting portion. 2. The radius of the inner sliding surface 14 of the guide rail 15, which determines the distance of the guide rail from the ring abutment of the piston ring 1 to be tightened, is approximately equal to the nominal diameter of the piston ring 1 to be tightened starting from the pole P. The piston ring tightening device according to claim 1, having a size of 0.55 to 0.80 times. 3 The nominal diameter of piston ring 1 to be tightened is 520
mm, the distance between the center point M of the piston ring and the pole P is 0.171 times the nominal diameter, and the radius of the inner sliding surface 14 of the guide rail 15 starting from the pole P is 0.677 times the nominal diameter. A piston ring tightening device according to claim 2. 4 Both expansion jaws 3 and 4 are attached to piston ring 1
2. The piston ring tightening device according to claim 1, wherein the points G and H that abut on the outside of the piston ring have a linear distance of approximately 0.5 to 0.9 times the nominal diameter of the piston ring when the device is not operated. 5. The two expansion jaws 3, 4 each consist of two parallel plates 19, 20, which in their lateral extension plane lie flat guide rails 1.
5 and a guide rail is received with a slight play between the two plates, and when the device 2 is used, the plates are located above and below the piston ring 1 which is to be expanded. and a deflection device 11, which at least partially covers the lower part of the device 2 and furthermore has gripping hooks 7, 8 supported on the ends of the device 2 assigned to the ring abutment.
furthermore, the guide member 12,
13. Piston ring tightening device according to claim 1, in which the plates 13; 16, 17 are received between the plates. 6. The first guide member 12, 13 of the respective expansion jaw 3, 4 is formed by a sliding shoe or a wall, which sliding shoe or wall connects the two parallel plates of the respective expansion jaw 3, 4. 19,
6. Piston ring tightening device according to claim 1, wherein the piston ring tightening device is fixedly connected to 20 and at the same time forms a spacer for the plate. 7. The second guide members 16, 17 of the respective expansion jaws 3, 4 are formed by rollers or pins, and the rollers or pins are rotatably supported between the parallel plates 19, 20. Claims 1 to 6, which are arranged so as to come into contact with the outer sliding surface 18 of the guide rail 15.
The piston ring tightening device according to any one of Items 1 to 9. 8. The second guide member 16, 17 of each expansion jaw 3, 4 is formed by a sliding shoe or wall, which slide shoe or wall extends between the two parallel plates 19, 20. 7. A piston ring tightening device according to claim 1, wherein the piston ring tightening device is fixedly connected. 9 abutment surfaces 9, 10 whose sliding shoes or walls are arranged perpendicularly to the plane of the plates 19, 20 of the respective expansion jaws 3, 4 and which rest against the outside of the piston ring and the inside of the guide rail 15; The piston ring tightening device according to claim 6, which has sliding surfaces 21 and 22 that come into contact with the sliding surface 14. 10. Claims 1 to 4 in which the expansion jaws 3 and 4 are made of welded or soldered structures.
The piston ring tightening device according to any one of Item 9. 11. The piston ring tightening device according to any one of claims 1 to 9, wherein the expansion jaws 3, 4 are formed of an integral cast member. 12. Piston ring tightening device according to any one of claims 1 to 11, wherein the guide rail 15 is of dimensionally stable design and manufactured from a suitable material. 13 Movement limiting pins 23, 24 are arranged on the guide rail 15 or on the respective expansion jaws 3, 4, which movement limiting pins are arranged on the expansion jaws 3, 4 or on the guide rails in order to limit the expansion stroke of the device. 13. Piston ring tightening device according to claims 1 to 12, which cooperates with corresponding stop surfaces 25, 26 at 15. 14 The inner sliding surface 14 and/or the outer sliding surface 18 of the guide rail 15 are provided with notches 37, 38 or flat surfaces 39, and the notches or flat surfaces are arranged as follows, that is, each The expansion jaws 3 and 4 have a certain amount of play with respect to the guide rail 15 when the device is not operated, and the device 2
Any one of claims 1 to 13 is spatially positioned such that a force-transmission-free engagement of the piston ring 1 to be expanded within the piston ring is possible.
The piston ring tightening device described in . 15. When used for the expansion of small piston rings 1 with a nominal diameter of up to approximately 300 mm:
The deflection device 11 for the expansion jaws 3, 4 comprises two hand levers 27, 28 and a return spring 29, which are rigidly fixed to the expansion jaws 3, 4 or formed therein. , wherein the return spring is tightened between the two expansion jaws 3, 4 and is adapted to return the expansion jaws from the deflection position to the starting position. - The piston ring tightening device according to any one of items 14 to 14. 16 When used for expanding medium-sized piston rings 1 with a nominal diameter of up to approximately 600 mm:
The deflection device 11 for the expansion jaws 3, 4 consists of two acutely bent hand levers 30, 31 which deflect the expansion jaws 3 by compressing the outer ends of the expansion jaws. , 4 are connected to the expansion jaws 3, 4 and are pivotably connected to the other via a hinge 32, such that the hand levers 30, 31 are deflected from their starting position. A piston ring tightening device according to any one of claims 1 to 14. 17. Patent in which the deflection device has a mechanically, pneumatically or hydraulically operated booster when used for expanding large piston rings with a nominal diameter of 600 mm or more. Claims Paragraph 1～
The piston ring tightening device according to any one of Item 16.