EP1741881B1 - Valve spring retainer with radial force enhancment - Google Patents

Abstract

The valve spring disk (11) can be directly engaged in an annular groove in the valve stem. The valve spring rests on an annular disk (12) and two support tongues (13) extending radially inward from it. The radially inner edges of the tongues have recesses for fitting in the annular groove, reducing the tongue end spacing for axial support from the spring side.

Description

The invention relates to a spring plate for a valve spring of an internal combustion engine, which is directly connectable to the valve stem of a gas exchange valve under engagement in an annular groove in the valve stem. Spring plates of this type hold and center the valve springs of gas exchange valves which are arranged concentrically to the valve stem and in particular supported by a second spring plate on the cylinder head. In this case, the valve actuation via the exertion of compressive forces on the over the spring plate protruding free end of the valve stem by cams, rocker arms or drag lever, wherein between these actuators and the spring plate clearance compensation devices can be used.

From the US 5,275,376 Spring plate for valve springs with an annular disc for supporting the valve spring and four individual from this annular disc radially outwardly directed supports are known. The support tongues are tapered in an axial section in a wedge shape toward the base or towards the free end and form an inner conical contact surface which is seated free of play on a cone section of a valve stem.

From the US Pat. No. 3,612,016 Spring plate for valve springs with an annular disk for resting on the valve spring and three individual from this annular disc radially outwardly directed support tongues are known. A bearing surface for the valve spring on the annular disc is axially closer to the end of a valve stem, as the free inner ends of the support tongues, which engage in an annular groove on the valve stem. An amplification of the supporting forces on the supporting tongues is not given here with an axial load on the annular disc. The spring plate is also sheet metal of uniform thickness.

From the US 1 453 471 is a spring plate for valve springs with an annular disc for resting on the valve spring and two of this annular disc radially inwardly directed outriggers, which are formed on the outer edge of the annular disk known. The supports connect with a C-shaped bend on the outer edge of the annular disc and are straight in the further course up to its free end. The spring plate is made of sheet metal of uniform thickness.

From the US 5,343,835 Spring plate for valve springs with an annular disc for resting on the valve spring and four individual from this annular disc radially inwardly directed supports are known, which are monotonically curved from the annular disc in axial section and bear flat against the inside of their free ends on a cone portion of a valve stem , The spring plate has a uniform material thickness.

Object of the present invention is to provide a comparison with these known devices improved short and stiff spring plate and an arrangement of such a spring plate and a gas exchange valve.

The solution consists in a spring plate for a valve spring of a Brenrikraftmaschine, which is directly connected to the valve stem of a gas exchange valve engaged with an annular groove in the valve stem, with an annular disc for resting on the valve spring and individual from this annular disc radially outwardly directed support tongues whose inner ends in plan view of the spring plate have recesses for engaging in the annular groove, wherein the support tongues are designed so that with axial support of the annular disc from the valve spring side and axial loading of the support tongues in the direction of the valve spring side towards the distance between the inner ends of the individual Support tongues is reduced, or wherein the support tongues are designed so that when axial support of the annular disc from the valve spring side and axial loading of the support tongues in the direction of the valve spring side of the system pressure between the inner ends of the individual Abstüt is enlarged, and wherein the inner ends of the supports to one of Slits divided support sleeve are formed, the wall thickness decreases towards its free end and wherein in the axial section through the spring plate in the middle by the supporting tongues in each case an annular disc half, each with a support tongue S-shaped or Z-shaped.

The solution further consists in a corresponding arrangement of a gas exchange valve of an internal combustion engine having a valve stem with an annular groove and a spring plate for a valve spring which is directly connected to the valve stem under engagement with the annular groove, wherein the spring plate with an annular disc for resting on the valve spring and individual from this annular disc radially outwardly directed support tongues whose inner ends in view of the annular disc recesses for engagement in the annular groove is provided, wherein in axial support of the annular disc by the valve spring and axial loading of the support tongues by a ring flank in the annular groove in the direction of the valve spring side, the distance between the inner ends of the individual support tongues is reduced, or wherein the support tongues are designed so that in axial support of the annular disc by the valve spring and axial loading of the support tongues by a ring flank in the annular groove in the direction of the valve spring side towards the system pressure between the inner ends of the individual support tongues is increased, and wherein the inner ends of the support tongues are formed into a slotted support sleeve whose wall thickness decreases towards its free end and wherein in axial section through the spring plate centered by the supporting tongues in each case an annular disc half, each with a support tongue S-shaped or Z-shaped runs

When loading the arrangement during operation is thus increased with increasing spring force by depressing the valve stem according to the first variant, the radially directed supporting force of the spring plate on the valve stem, so that a rigid connection is formed and a turning of the support tabs is excluded, or according to the second variant mutual supporting force between the supporting tongues increases, so that the spring plate braces as a structural element and so a turning of the supporting tongues remains excluded.

Here, in a preferred embodiment, it is proposed that the inner annular edges of the support tongues are spaced axially relative to a support line for the valve spring on the annular disc in the direction of the end of the valve stem. It is further provided that straight lines include an obtuse angle through the inner annular edges of the support tongues and the support line for the valve spring on the annular disc, which opens in the direction of the valve spring. It is further proposed that the number of Abstützzungen is limited to two. Hereby, a much stiffer design without substantial increase in mass can be achieved. The production of the spring plate and the mountability of the arrangement are also significantly simplified.

According to a preferred form of the spring plate is provided that are formed in plan view of the spring plate between the supporting tongues and the annular disc two opposing crescent-shaped Ausbrechungen side to the support tongues.

In a further embodiment it can be provided that the recesses at the inner ends of the support tongues complement each other in a plan view of the spring plate to the circle. Alternatively, it is possible that the recesses at the inner ends of the support tongues complement each other in plan view of the spring plate to an oval whose shorter inner dimension extends in the direction of the supporting tongues. While in the first alternative, a substantially uniform edge load is achieved in an advantageous manner, in the second alternative, a slight tilting of the spring plate for self-aligning on the valve stem in adaptation to the valve spring is possible.

The preferred production of the spring plate according to the invention is that the product is first pulled and punched from an annular disk or a blank. This is followed by a heat treatment, a subsequent shot peening and grinding at least the end face to rest in the annular groove and the inner edges, which form the insertion.

Figur 1

zeigt einen erfindungsgemäßen Federteller in einer ersten Ausführung

1. a) in isometrischer 3D-Darstellung
2. b) in Draufsicht
3. c) im Schnitt entlang der Linie A-A nach Darstellung b)
4. d) im Schnitt gemäß der Schnittlinie B-B nach Darstellung b)
5. e) in einer vergrößerten Einzelheit der Darstellung c)
6. f) in einer vergrößerten Einzelheit der Darstellung d);

Figur 2

zeigt einen Federteller nach Figur 1 a in vergrößerter bezifferter Darstellung;

Figur 3

zeigt das Ende eines Ventilschafts eines Gaswechselventils zur Verbindung mit einem erfindungsgemäßen Federteller nach Figur 1;

Figur 4

zeigt eine erfindungsgemäße Anordnung aus einem Federteller nach Figur 1 und dem Ventilschaft eines Gaswechselventils;

Figur 5

zeigt einen erfindungsgemäßen Federteller in einer zweiten Ausführung

1. a) in isometrischer 3D-Darstellung
2. b) in Draufsicht
3. c) im Schnitt entlang der Linie A-A nach Darstellung b)
4. d) im Schnitt gemäß der Schnittlinie B-B nach Darstellung b);

Figur 6

zeigt einen Federteller nach Figur 5a in vergrößerter bezifferter Darstellung;

Figur 7

zeigt das Ende eines Ventilschafts eines Gaswechselventils zur Verbindung mit einem erfindungsgemäßen Federteller nach Figur 5;

Figur 8

zeigt eine erfindungsgemäße Anordnung aus einem Federteller nach Figur 5 und dem Ventilschaft eines Gaswechselventils;

Preferred embodiments of the invention as well as devices according to the invention for their assembly are shown in the drawings and will be described below.

FIG. 1

shows a spring plate according to the invention in a first embodiment

1. a) in isometric 3D representation
2. b) in plan view
3. c) in section along the line AA according to illustration b)
4. d) in section along the section line BB according to illustration b)
5. e) in an enlarged detail of the illustration c)
6. f) in an enlarged detail of the representation d);

FIG. 2

shows a spring plate FIG. 1 a in enlarged figured representation;

FIG. 3

shows the end of a valve stem of a gas exchange valve for connection with a spring plate according to the invention FIG. 1 ;

FIG. 4

shows an inventive arrangement of a spring plate of Figure 1 and the valve stem of a gas exchange valve;

FIG. 5

shows a spring plate according to the invention in a second embodiment

1. a) in isometric 3D representation
2. b) in plan view
3. c) in section along the line AA according to illustration b)
4. d) in section along the section line BB according to representation b);

FIG. 6

shows a spring plate FIG. 5a in enlarged figured representation;

FIG. 7

shows the end of a valve stem of a gas exchange valve for connection with a spring plate according to the invention FIG. 5 ;

FIG. 8

shows an inventive arrangement of a spring plate after figure 5 and the valve stem of a gas exchange valve;

The individual representations of the FIG. 1 and the FIG. 2 will be described together below. On an inventive spring plate 11, an outer annular disc 12 and two of these radially inwardly projecting support tongues 13 can be seen. The number of supporting tongues 13 is limited to two here in a preferred manner. The spring plate 11 in total and in particular the support tongues 13 are symmetrical to a sectional plane AA through the center axis Z of the spring plate 11. The inner ends 14 of the support tongues 13 have in the tension-free position of the spring plate 11 shown here a distance d from each other in the direction of the sectional plane BB , The front ends 14 of the support tongues 13 have approximately semicircular recesses 15, which together form an insertion opening 16. With the recesses 15, the support tongues 13 can be axially and radially supported in an annular groove of a valve stem of a gas exchange valve of an internal combustion engine under engagement in the annular groove. The shape of the recesses 15 can complement each other to form a circle or form an oval whose major axis extends in the direction of the sectional plane AA. In principle, the insertion opening 16 formed by the recesses 15 can also be designed as a polygon in plan view, which inscribes the previously described curves (circle or oval). The support tongues 13 are configured such that between the support tongues 13 and the annular disc 12 two opposite crescent-shaped Ausbrechungen 17 form. With a circular line the support or support line 18 is marked for a valve spring on the annular disc 12. The diameter Ø18 of the support line 18 thus corresponds to the mean winding diameter of an associated helical valve spring. The intended position of the valve spring is below the spring plate in the representation of the top view FIG. 1b to accept. Visible is thus the top of the spring plate, which hangs with its underside on the valve spring, which is not shown. The supporting tongues 13 are deformed in the region of the inner ends 14 to form a centrally divided support sleeve 19, which forms two slots 24 of constant width (d) between the supporting tongues 13. The substantially constant wall thickness having material of the entire spring plate 11 is reduced in the region of the support sleeve 19. The insertion opening 16 is made of an inner cylinder portion 20 having a diameter ∅20 and an inner cone portion 21 formed with an acute opening angle α21. The opening angle α21 may preferably be in the order of 5-10 °, in particular at 8.5 °. The wall thickness of the support sleeve 19 is decreasing towards the free end of the support sleeve 19, wherein an outer cone surface 22 forms a larger opening angle α22 than the inner cone portion 21, wherein the opening angle α22 are preferably in the order of 20-30 °, in particular 26 ° can. In section BB can be seen that the spring plate halves are each S-shaped curved in section through the supporting tongues 13 and pass approximately tangentially into the support sleeve 19. With an inner support edge 23 on an end face 25 at the free end of the support sleeve 19, the spring plate 11 is supported in an annular groove on the valve stem when loaded by the valve spring. Straight lines through the support line 18 on the spring plate underside and through the support edge 23, which are also shown, create an obtuse opening angle α23, which opens to the valve spring side. This means in other words that an axial distance between the support line 18 on the spring plate underside and the support edge 23, which has a smaller diameter than the support line 18, is present. This causes that under load of the spring plate 11 by the valve spring on the one hand, which acts on the annular disc 12, and by the valve stem on the other hand, which acts by means of an annular groove on the supporting tongues 13, an infinitesimal deformation of the supporting tongues 13 is effected, which tends to Width of the slots 24 is reduced, so that the support sleeve 19 applies with increased radial bias in the groove bottom of the annular groove in the valve stem. The effective bending movements of the supporting tongues 13 are in this case extremely low, since the support tongues 13 can already sit without clearance after installation, in particular with radial prestress in the annular groove of the valve stem.

The FIGS. 3 and 4 will be described together below. It is shown the aborted illustrated valve stem 31 of a gas exchange valve in which a small distance from a pressure surface 32 for a cam or the like, an annular groove 33 is formed in a rectangular shape, the groove bottom has the diameter 033. This diameter ∅33 is greater than the diameter ∅20 of the cylinder portion 20 of the support sleeve 19 of the spring plate 11 in the relaxed state. In FIG. 3 the spring plate 11 is mounted in the annular groove 33, wherein he is with the support edge 23 and its end face 25 on a ring flank 34 of the annular groove 33 is supported and bears with the cylinder portion 20 of the support sleeve 19 under bias at the bottom of the annular groove.

The individual representations of the FIG. 5 and the FIG. 6 will be described together below. On an inventive spring plate 11 'are an outer annular disc 12' and two of this radially inwardly projecting support tongues 13 'can be seen. The number of supporting tongues 13 'is limited to two here in a preferred manner. The spring plate 11 'overall and in particular the support tongues 13' are symmetrical to a sectional plane AA through the central axis Z of the spring plate 11 '. The inner ends 14 'of the support tongues 13' lie in the position shown here of the spring plate 11 'in the sectional plane AA stress-free or supporting with pressure bias touching to each other. The front ends 14 'of the support tongues 13' have recesses 15 'which form an insertion opening 16'. With the recesses 15 ', the support tongues 13' can be axially supported in an annular groove of a valve stem of a gas exchange valve of an internal combustion engine by engaging in the annular groove. The shape of the recesses 15 'can complement each other to form a circle or form an oval whose major axis extends in the direction of the sectional plane AA. In principle, the insertion opening 16 'formed by the recesses 15' can also be designed as a polygon in plan view, which inscribes the previously described curves (circle or oval). The support tongues 13 'are designed so that between the support tongues 13' and the annular disc 12 'form two opposite crescent-shaped Ausbrechungen 17'. With a circular line the support or support line 18 for a valve spring on the annular disc 12 'is marked. The diameter ∅18 of the support line 18 thus corresponds to the mean turn diameter of an associated helical valve spring. The intended position of the valve spring is below the spring plate in the representation of the top view FIG. 1b to accept. Visible is thus the top of the spring plate, which hangs with its underside on the valve spring, which is not shown. The support tongues 13 'are deformed in the region of the inner ends 14' to a centrally divided support sleeve 19 ', which forms two slots 24' of wedge-shaped form between the support tongues 13 '. The substantially constant wall thickness material of the entire spring plate 11 'is reduced in the region of the support sleeve 19'. The insertion opening 16 'is formed of an inner cylinder portion 20' with a diameter ∅20 and an inner cone portion 21 'with an opening angle α21'. The opening angle α21 'may preferably be in the order of 40-60 °, in particular at 50 °. The wall thickness of the support sleeve 19 'is decreasing towards the free end of the support sleeve 19', wherein an outer cone surface 22 forms an opening angle α22, which may preferably be in the order of 20-30 °, in particular at 26 °. In section BB can be seen that the spring plate halves are each S-shaped curved in section through the supporting tongues 13 'and pass approximately tangentially into the support sleeve 19'. With an end face 25 ', in particular with an inner support edge 23 at the free end of the support sleeve 19', the spring plate 11 'is supported in an annular groove on the valve stem under load by the valve spring. Straight lines through the support line 18 'on the underside of the spring plate and through the support edge 23', which are also drawn, create an obtuse opening angle α23 ', which opens to the valve spring side. This means, in other words, that an axial distance between the support line 18 'on the spring plate underside and the support edge 23, which has a smaller diameter than the support line 18', is present. This causes that upon loading of the spring plate 11 'by the valve spring on the one hand, which acts on the annular disc 12, and by the valve stem on the other hand, which acts by means of an annular groove on the supporting tongues 13', an infinitesimal deformation of the supporting tongues 13 'is effected which tends to widen the wedge-shaped shape of the slots 24 ', so that the support sleeve 19' with increased axial bias axially against the annular edge 34 of the annular groove 33 in the valve stem applies. The effective bending movements of the supporting tongues 13 'are extremely small here, since the support tongues 13' abut against each other after assembly, already without clearance, in particular with radial prestressing, wherein the support sleeve 19 'is seated with radial clearance in the annular groove of the valve stem.

The FIGS. 7 and 8 will be described together below. It is the aborted illustrated valve stem 31 'of a gas exchange valve shown in which a small distance from a pressure surface 32' for a cam or the like, an annular groove 33 'is formed in a rectangular shape, the groove bottom has the diameter 033'. This diameter ∅33 'is smaller than the diameter ∅20 of the cylinder portion 20 'of the support sleeve 19' of the spring plate 11 'in the relaxed state. In Figure 9, the spring plate 11 'is mounted in the annular groove 33', wherein it is supported with the support edge 23 'and its end face 25' on a ring flank 34 'of the annular groove 33', while the support sleeve 19 'radial clearance against the groove bottom the annular groove 33 'has, so that the spring plate 11' with the valve spring, not shown, is freely rotatable relative to the valve stem of the gas exchange valve.

LIST OF REFERENCE NUMBERS

11

spring plate

12

washer

13

supporting tongue

14

inner end

15

recess

16

insertion

17

break-away

18

support line

19

support sleeve

20

cylinder section

21

cone section

22

conical surface

23

supporting edge

24

slot

25

face

31

valve stem

32

effective area

33

ring groove

34

ring side

Claims (11)

1. A spring plate (11) for a valve spring of an internal combustion engine, which spring plate (11) is directly connectable to the valve stem (31) of a charge changing valve by engaging an annular groove (33) in the valve stem (31);
   having an annular disc (12) for being positioned on the valve spring and individual supporting tabs (13) which are directed radially inwardly from said annular disc (12) and whose inner ends (14), in a plan view of the spring plate (11), comprise recesses (15) for engaging the annular groove (33);
   wherein the supporting tabs (13) are designed in such a way that, when the annular disc (12) is axially supported from the direction of the valve spring end and when the supporting tabs (13) are axially loaded towards the valve spring end, the distance between the inner ends (14) of the individual supporting tabs (13) is reduced,
   characterised in
   that the inner ends (14) of the supporting tabs (13) are formed into a supporting sleeve (19) divided by slots (24), wherein the wall thickness of the supporting sleeve (19) decreases towards its free end and that, in the axial section (B-B) through the spring plate (11) extending centrally through the supporting tabs (13), there extends an annular disc half (12) with a supporting tab (13) in an S-like or Z-like way.
2. A spring pilate (11) for a valve spring of an internal combustion engine, which spring plate (11) is directly connectable to the valve stem (31) of a charge changing valve by engaging an annular groove (33) in the valve stem (31);
   having an annular disc (12) for being positioned on the valve spring and individual supporting tabs (13) which are directed radially inwardly from said annular disc (12) and whose inner ends (14), in a plan view of the spring plate (11), comprise recesses (15) for engaging the annular groove (33);
   wherein the supporting tabs (13) are designed in such a way that, when the annular disc (12) is axially supported from the direction of the valve spring end and when the supporting tabs (13) are axially loaded towards the valve spring end, the contact pressure between the inner ends (14) of the individual supporting tabs (13) is increased,
   characterised in
   that the inner ends (14) of the supporting tabs (13) are formed into a supporting sleeve (19) divided by slots (24), wherein the wall thickness of the supporting sleeve (19) decreases towards its free end and that, in the axial section (B-B) through the spring plate (11) extending centrally through the supporting tabs (13), there extends an annular disc half (12) with a supporting tab (13) in an S-like or Z-like way.
3. A spring plate according to any one of claims 1 or 2,
   characterised in
   that inner supporting edges (23) of the supporting tabs (13) are axially spaced relative to a contact line (18) for the valve spring at the annular disc (12) towards the end of the valve stem.
4. A spring plate according to any one of claims 1 to 3,
   characterised in
   that straight lines through the inner supporting edges (23) of the supporting tabs (13) and the contact line (18) for the valve spring at the annular disc (12) enclose an obtuse angle α 23 which opens towards the valve spring.
5. A spring plate according to any one of claims 1 to 4,
   characterised in
   that there are provided two radially opposed supporting tabs (13).
6. A spring plate according to any one of claims 1 to 5,
   characterised in
   that, in a plan view of the spring plate (11), between the supporting tabs (13) and the annular disc (12), there are formed two opposed sickle-shaped broken-out portions (17) laterally relative to the supporting tabs (13).
7. An assembly consisting of a charge changing valve of an internal combustion engine with a valve stem (31) with an annular groove (33) and a spring plate (11) for a valve spring, which spring plate (11) is directly connected to the valve stem (31) by engaging the annular groove (33), wherein the spring plate (11) is provided with an annular disc (12) for being positioned on the valve spring and individual supporting tabs (13) which are directed radially inwardly from said annular disc (12) and whose inner ends (14), in a plan view of the annular disc, comprise recesses (15) for engaging the annular groove (33),
   wherein the supporting tabs (13) are designed in such a way that, when the annular disc (12) is axially supported by the valve spring and when the supporting tabs (13) are axially loaded by an annular flank (34) in the annular groove (33) towards the valve spring end, the distance between the inner ends (14) of the individual supporting tabs (13) is reduced,
   characterised in
   that the inner ends (14) of the supporting tabs (13) are formed into a supporting sleeve (19) divided by slots (24), wherein the wall thickness of the supporting sleeve (19) decreases towards its free end and that, in the axial section (B-B) through the spring plate (11) extending centrally through the supporting tabs (13), there extends an annular disc half (12) with a supporting tab (13) in an S-like or Z-like way.
8. An assembly consisting of a charge changing valve of an internal combustion engine with a valve stem (31) with an annular groove (33) and a spring plate (11) for a valve spring, which spring plate (11) is directly connected to the valve stem (31) by engaging the annular groove (33), wherein the spring plate (11) is provided with an annular disc (12) for being positioned on the valve spring and individual supporting tabs (13) which are directed radially inwardly from said annular disc (12) and whose inner ends (14), in a plan view of the annular disc, comprise recesses (15) for engaging the annular groove (33),
   wherein the supporting tabs (13) are designed in such a way that, when the annular disc (12) is axially supported by the valve spring and when the supporting tabs (13) are axially loaded by an annular flank (34) in the annular groove (33) towards the valve spring end, the contact pressure between the inner ends (14) of the individual supporting tabs (13) is increased,
   characterised in
   that the inner ends (14) of the supporting tabs (13) are formed into a supporting sleeve (19) divided by slots (24), wherein the wall thickness of the supporting sleeve (19) decreases towards its free end and that, in the axial section (B-B) through the spring plate (11) extending centrally through the supporting tabs (13), there extends an annular disc half (12) with a supporting tab (13) in an S-like or Z-like way.
9. An assembly according to any one of claims 7 or 8,
   characterised in
   that inner supporting edges (23) of the supporting tabs (13) are axially spaced relative to a contact line (18) for the valve spring at the annular disc (12) towards the end of the valve stem (31).
10. An assembly according to any one of claims 7 to 9,
    characterised in
    that straight lines through the inner supporting edges (23) of the supporting tabs (13) and the contact line (18) for the valve spring at the annular disc (12) enclose an obtuse angle which opens towards the valve spring.
11. An assembly according to any one of claims 7 to 10,
    characterised in
    that the annular groove (33) is provided in the form of a rectangular groove.

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