DE102020113026A1 - Valve elements with spur radial connection - Google Patents

Abstract

The invention relates to a rotary slide valve (20) with a first valve element which is firmly connected to a second valve element, the first valve element (22) having an insertion section (28) with a convex first end face (30), the convex first end face (30) has a flat (32),
- The second valve element (24) has a receiving channel (38) for receiving the insertion section (28) of the first valve element (22), the receiving channel (38) having a concave bottom surface corresponding to the convex first end face (30) of the insertion section (28) (40) and the insertion section (28) of the first valve element (22) can be inserted into the receiving channel (38) of the second valve element (24) in such a way that the convex first end face (30) comes to rest against the concave bottom surface (40) , wherein an outer contour of the insertion section (28) and an inner contour of the receiving channel (38) at least in sections have a polygonal cross section,
- characterized in that the convex first end face (30) has a flat (32).

Description

The present invention relates to a rotary slide valve with a first valve element which is firmly connected to a second valve element.

The invention thus relates to a steering valve for power steering. In such a steering valve, an input shaft (also referred to here as a second valve element) and an output shaft are connected to one another via a torsion bar. A rotary slide valve (also referred to here as the first valve element) is firmly connected to the input shaft. Such a rotary slide valve is, for example, from DE 19633633 A1 known. Further prior art is from US2016 / 0033050A1 , US4557464A , FR1336578A , US8424837B2 , US3523551A , US6877523B2 and US1481323A known.

The connection of the rotary valve to the input shaft is essential for the transmission of the steering torque. The connection is also important for the driver's steering feel, since a rotation of the steering wheel should cause the wheels to move as precisely as possible.

A major problem with the connection of the rotary valve to the input shaft is that the connection wears over time and play can develop. This means that turning the steering wheel does not lead directly to a movement of the steered wheels, since the two valve elements can rotate freely against each other by a certain amount. In addition, there may be interference noises when steering.

Furthermore, the connection between the two valve elements must enable maximum torque transmission and at the same time have precise concentricity. For this reason, previously known methods of prestressed connections, such as spline connections, spur tooth connections or circular wedge connections, cannot be used.

the DE102018115482A1 shows a rotary slide valve, which is designed to ensure a backlash-free connection between rotary slide valve and input shaft. For this purpose, the rotary slide valve is positively connected to the input shaft via a convex end face of the rotary slide valve with a concave bottom surface of the input shaft, the shaft of the rotary slide valve also has a non-circular area for transmitting torque.

In the case of such a connection, however, it has been shown that due to wear on the convex / concave surfaces under high loads, it cannot be guaranteed that the connection will still be free of play even after a certain period of use. In this design, wear usually occurs because either the convex / concave surfaces are exposed to too great a torque or, due to manufacturing tolerances, sub-areas of the surfaces that are too small come into engagement with one another.

The object of the invention is therefore to propose an advantageous connection between two valve elements, preferably a rotary slide valve and an input shaft, which does not have the disadvantages of the prior art. In particular, the connection should ensure the transmission of a maximum torque while at the same time ensuring precise concentricity of the connection. In particular, it is also essential that the connection is free of play and, if possible, remains free of play over a long period of use.

• - das erste Ventilelement einen Einsteckabschnitt mit einer stirnseitigen konvexen/ersten Stirnfläche aufweist,
• - das zweite Ventilelement einen Aufnahmekanal zur Aufnahme des Einsteckabschnitts des ersten Ventilelements aufweist, wobei der Aufnahmekanal eine mit der konvexen/ersten Stirnfläche des Einsteckabschnittes korrespondierende konkave Bodenfläche aufweist und der Einsteckabschnitt des ersten Ventilelements in den Aufnahmekanal des zweiten Ventilelements derart einführbar ist, dass die konvexe/erste Stirnfläche an der konkaven Bodenfläche zur Anlage kommt, wobei eine Außenkontur des Einsteckabschnitts und eine Innenkontur des Aufnahmekanals zumindest abschnittsweise einen polygonen Querschnitt aufweisen,

dadurch gekennzeichnet, dass die konvexe erste Stirnfläche eine Abflachung aufweist.The object is achieved in that

• - the first valve element has an insertion section with an end face convex / first end face,
• - The second valve element has a receiving channel for receiving the insertion section of the first valve element, wherein the receiving channel has a concave bottom surface corresponding to the convex / first end face of the insertion section and the insertion section of the first valve element can be inserted into the receiving channel of the second valve element in such a way that the convex / the first end face comes to rest on the concave bottom surface, an outer contour of the insertion section and an inner contour of the receiving channel having a polygonal cross-section at least in sections,

characterized in that the convex first end face has a flattening.

Due to the polygonal cross section of the two connecting elements, the connection according to the invention is able to transmit maximum torques. The cross-section can be polygonal shapes such as P4C or P3C DIN 32712-1 exhibit. These connections have the advantage that they can transmit high torques. The polygonal surfaces can be separated from the convex / concave surfaces, but they can also merge into one another. However, other cross-sections that are designed to be rotationally symmetrical with respect to a central axis are also conceivable and advantageous. This avoids an imbalance. For example, oval or star-shaped cross-sections are conceivable.

In order to ensure a backlash-free connection, the plug-in section of the first valve element has a convex end face which, in the plugged-in state, comes to rest on a concave bottom surface of the receiving channel. The contact between the two dome-shaped or spherical surfaces ensures a permanent backlash-free connection of the two valve elements. The two spherical surfaces have the same radius. At higher loads, such a connection initially comes into the range of elastic deformation. The polygon connection is designed in such a way that it comes into play more and more at higher loads in order to prevent the convex / concave connection from undergoing plastic deformation. In this way, high torques can be transmitted, and at the same time freedom from play can be guaranteed over the long term.

The convex end face also has a flattening. In the case of unfavorable manufacturing tolerances of the convex face and the corresponding concave face, such as, for example, if the radii in the concave face are too large and / or the radii in the convex face are too small, only a very small area of the convex face would have contact with the concave face. By flattening at this point, the resulting flanks come into play and the force transmission between the convex and concave surface takes place over a larger area. In this way, the connection becomes less sensitive to manufacturing tolerances and at the same time more resilient. The freedom from play can thus be guaranteed over a longer service life.

In a particularly advantageous embodiment variant, the two valve elements can additionally be connected to one another or additionally secured by a connecting means. For example, the end face of the first valve element can have a threaded bore into which a connecting screw can be screwed. The connecting screw extends through a screw opening in the second valve element. The threaded hole and, accordingly, the connecting screw and the screw opening are arranged on a common central axis of the two valve elements. In a particularly advantageous embodiment variant, the connecting screw is designed as an expansion screw in order to maintain a preload for as long as possible even during operation.

The concave bottom surface within the second connecting element can be generated mechanically, for example, by a bore made from the outside transversely to the central axis. This creates at least one opening in the wall section of the receiving channel. In order to achieve a weight distribution that is as uniform as possible, it is also possible to create an opposite second opening, for example by inserting the drill deeply in one work step.

• 1: ein erfindungsgemäßes Ventilelement in Frontansicht mit Kennzeichnung der Schnittebenen der Schnitte C und D,
• 2: den Schnitt D aus 1, wobei die konkaven/konvexen Flächen des erfindungsgemäßen Ventilelements zu erkennen sind ,
• 3: den Schnitt C der 1, wobei die polygonen Formen des Einsteckabschnitts und des Aufnahmekanals zu erkennen sind,
• 4: das erfindungsgemäße Ventilelement in Seitenansicht mit Kennzeichnung der Schnittebene des Schnitts A,
• 5: den Schnitt A aus 4 und einen Detailbereich B mit Abflachung der konvexen Fläche.

The invention is explained in more detail with reference to the following figures. These are only to be understood as examples and are not intended to restrict the invention to the exemplary embodiments shown. Show it:

• 1 : a valve element according to the invention in a front view with identification of the sectional planes of the sections C and D,
• 2 : cut D from 1 , whereby the concave / convex surfaces of the valve element according to the invention can be seen,
• 3 : the section C the 1 , whereby the polygonal shapes of the plug-in section and the receiving channel can be seen,
• 4th : the valve element according to the invention in side view with identification of the cutting plane of section A,
• 5 : cut A from 4th and a detail area B with a flattening of the convex surface.

the 1 until 5 show the elements essential for the invention of a rotary slide valve, which is not completely shown 20th . A first valve element is shown 22nd , a second valve element 24 and a connecting screw 26th .

The first valve element 22nd has an insertion section 28 on. This is polygonal in cross section, such as in particular 3 made clear.

A first face 30th of the insertion section 28 is shaped convex according to the invention. It can be seen that the first end face 30th by a flattening 32 is interrupted. The flattening is in the middle at the tip between the two flanks of the end face 30th shown area. The convex first face 30th of component 22nd is therefore interrupted at the front by a, for example, milled surface. This is a franking 49 which ensures that even with different tolerances of the convex / concave surfaces 48 / 30th both valve element 22nd , 24 the tip of the male section 28 the convex first face 30th never comes to fruition. Otherwise, this could be the case if the concave surface (hole 48 ) of component 46 has larger roundings than the convex first end face 30th . To ensure that there is no play and that the preload is permanent, only the flanks of the first face may be used 30th wear.

It can also be seen that in the embodiment shown in the area of the flattening 30th of the insertion section 28 a threaded hole 34 is introduced into which the connecting screw also shown 26th can be screwed in (see in particular 5 ).

the 3 until 5 show the rotary slide valve 20th in the partially and fully assembled state. It can be seen that the coaxial arrangement to a central axis xx. The central axis xx also forms the axis of rotation of the rotary slide valve 20th .

In a particularly advantageous embodiment variant, the connection of the two valve elements 20th , 24 via the connecting screw 26th additionally secured. This is in the assembled state through a screw opening on the face 42 in the second valve element 24 into the threaded hole 34 of the insertion section 28 of the first valve element 22nd screwed in. In the exemplary embodiments shown, the screw opening is 42 designed in such a way that a screw head is completely within a second end face 46 of the second valve element 24 is recorded. The connecting screw 36 can preferably be designed as an expansion screw around the two valve elements 22nd , 24 to keep under tension.

The valve element 24 has a hole on the side 48 on. This results from the introduction of the concave bottom surface 40 from the outside, for example by a drilling process. The creation of the concave bottom surface 40 using a drilling tool is quick and easy to do.

The invention is not restricted to the exemplary embodiments shown, but rather also shows further design variants. In particular, the figures are not true to scale in all details; they only serve to illustrate the invention and the elements shown. For example, the two valve elements 22nd , 24 also be formed by other elements. In particular, the first valve element can be formed by the input shaft and the second valve element by the rotary slide valve.

List of reference symbols

20th

Rotary slide valve

22nd

first valve element (rotary slide valve)

24

second valve element (input shaft)

26th

Connecting screw

28

Insertion section

30th

first face

32

Flattening

34

Threaded hole

38

Recording channel

40

Floor area

42

Screw opening

46

second face

48

drilling

49

Franking

A.

Section A

B.

Detail area B

C.

Section C

D.

Section D

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19633633 A1 [0002]
• US 2016/0033050 A1 [0002]
• US 4557464 A [0002]
• FR 1336578 A [0002]
• US 8424837 B2 [0002]
• US 3523551 A [0002]
• US 6877523 B2 [0002]
• US 1481323 A [0002]
• DE 102018115482 A1 [0006]

Non-patent literature cited

• DIN 32712-1 [0010]

Claims (7)

Rotary slide valve (20) with a first valve element which is firmly connected to a second valve element, wherein - the first valve element (22) has an insertion section (28) with a convex first end face (30), - the second valve element (24) has a Receiving channel (38) for receiving the plug-in section (28) of the first valve element (22), the receiving channel (38) having a concave bottom surface (40) corresponding to the convex first end face (30) of the plug-in section (28) and the plug-in section ( 28) of the first valve element (22) can be introduced into the receiving channel (38) of the second valve element (24), and the convex first end face (30) comes to rest against the concave bottom surface (40), an outer contour of the insertion section (28) and an inner contour of the receiving channel (38) at least partially have a polygonal cross-section, characterized in that the convex first end face (30) has a shoulder laughter (32). Rotary slide valve (20) Claim 1 , characterized in that the non-round sections of the insertion section (28) and the receiving channel (38) are designed to be rotationally symmetrical about a central axis XX. Rotary slide valve (20) Claim 1 or Claim 2 , characterized in that the non-round sections have the shape of P4C polgon profiles. Rotary slide valve (20) according to one of the Claims 1 until 3 , characterized in that the two valve elements (22, 24) can be screwed together via a coaxially extending connecting screw (26), the rotary slide valve (22) having a threaded hole (34) in its first end face (30) and the second valve element (24) has a screw opening (42) in its second end face (46). Rotary slide valve (20) according to one of the Claims 1 until 4th , characterized in that the bottom surface (40) laterally adjoins a bore (48), the concave bottom surface being designed as a partial cylinder surface and the radius of the bore (48) corresponding to the radius of the partial cylinder surface. Rotary slide valve (20) Claim 4 or 5 , characterized in that the screw opening (42) is designed such that a screw head of the connecting screw (36) is countersunk in the screwed state of the valve elements (22, 24) in the second valve element (24). Rotary slide valve (20) according to one of the Claims 1 until 6th , characterized in that the first valve element (22) is designed as a rotary slide valve and the second valve element (24) is designed as an input shaft.

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