DE102016110291A1 - Method for producing torsion springs for a camshaft adjuster of a motor vehicle engine, torsion spring for a camshaft adjuster of a motor vehicle engine, and camshaft adjuster therewith - Google Patents

Abstract

A method according to the invention for producing torsion springs (2) for a camshaft adjuster of an automotive engine comprises the following steps: feeding a spring wire (3) with a trapezoidal wire cross-section to a spring winding machine, so that the side of the wire cross-section with greater height, which is the radial outer side of the later Spring coils (12) forms, lies on the outside and the side of the wire cross section with a lesser height, which forms the radial inside of the later spring coils (12), inside; Winding the spring wire (3) in the spring winding machine into a substantially cylindrical torsion spring (2) with spring coils (12) and two spring wire ends (8, 10) bent substantially radially outwards from the end of the uppermost or lowermost spring coil, so that the spring coils (12) have a rectangular winding cross-section and whose two spring wire ends (8, 10) each have a trapezoidal wire cross-section; and cutting the wound spring wire (3) into individual torsion springs (2).

Description

The present invention relates to a method for producing torsion springs for a camshaft adjuster of an automotive engine, a torsion spring for a camshaft adjuster of an automotive engine, and a camshaft adjuster with a torsion spring according to the invention.

From the DE 10 2010 063 706 For example, there is known a torsion spring having a coil body with two spring ends, with one spring end extending radially outward from the coil body and the opposite spring end extending axially away from the coil body.

It is therefore an object of the present invention to provide a simple method for producing torsion springs, as well as torsion springs with improved spring characteristics, as well as to provide an improved camshaft adjuster with such a torsion spring.

This object is solved by the subject matter of the independent patent claims. Advantageous developments emerge from the dependent claims.

A method according to the invention for producing torsion springs for a camshaft adjuster of an automotive engine comprises feeding a spring wire with a trapezoidal wire cross section to a spring winding machine, so that the side of the wire cross section with a greater height, which forms the radial outside of the later spring windings, lies on the outside and the side of the spring Wire cross-section with a lesser height, which forms the radial inside of the later spring coils, lies inside. This is followed by the winding of the spring wire in the spring winding machine to a substantially cylindrical torsion spring with spring coils and two spring wire ends bent substantially radially outwards from the end of the foremost or rearmost spring turn, so that the spring turns have a rectangular winding cross section and their two spring wire ends each have a trapezoidal wire cross section exhibit.

This is followed by the cutting of the wound spring wire into individual torsion springs.

With the method according to the invention, torsion springs can be produced quickly and easily in one process step.

Unlike tension or compression springs torsion spring according to the invention is charged to rotate about its spring axis, in which the spring ends are rotated relative to each other.

According to a basic idea of the present invention, the torsion springs produced according to the invention are more compact than conventionally produced springs. The compactness manifests itself in a smaller block dimension of the torsion spring, whereby the torsion springs require a smaller installation space. In a given space thus a torsion spring according to the invention can be used, which has more spring coils and thus better spring properties than conventional torsion springs with trapezoidal spring coil cross-section. The block dimension of a torsion spring describes the height or the thickness of the torsion spring in the axial direction.

According to a further basic idea of the present invention, the actual block dimension of the torsion springs produced according to the invention is identical to the theoretical block dimension. In conventionally manufactured torsion springs, the actual block size differs from the theoretical block size.

According to a further basic idea of the present invention, the torsion springs produced by the method according to the invention have spring coils which can lie flush against one another, resulting in improved spring properties, in particular improved damping, a particularly homogeneous stress curve and a longer durability compared to conventional torsion springs.

The spring wire is fed either from a supply roll on which a spring wire with trapezoidal wire cross-section is rolled, the spring winding machine, or the spring wire with trapezoidal wire cross-section is pulled in front of the spring winding machine with a wire drawing machine and then fed directly to the spring winding machine. The trapezoidal spring wire is supplied to the spring winding machine so that the side of the wire cross section comes to rest with a lesser height on a winding cylinder.

A first spring wire end is guided in the spring wire winding machine, so that the first spring wire end projects beyond the winding cylinder. Then, the trapezoidal spring wire is wound around the winding cylinder until a plurality of spring coils have been created in this way. In the winding, the side of the wire cross-section with a smaller height in the radial direction is upset such that the trapezoidal wire cross section is converted into a rectangular wire cross section. The rectangular wire cross section enables a dynamically stable torsion spring.

The first spring wire end is bent in the spring wire winding machine, starting from the first spring coil radially outward, whereby the area between the spring wire end and the spring coil retains the original trapezoidal wire cross section.

The second spring wire end is also bent radially outwards starting from the last spring coil and the area between the spring wire end and spring coil retains the original trapezoidal wire cross section.

The two spring wire ends are particularly easy to produce, because they are bent by a simple bending mechanism radially outward.

The cutting of the wound spring wire into individual torsion springs allows a quick further processing of the torsion springs and allows a high efficiency in the production.

When cutting the second spring wire end retains its trapezoidal wire cross-section. The trapezoidal spring wire ends provide good fixation in all transverse directions when inserting the spring wire ends in a correspondingly adapted receiving space, in particular in a receiving space of a camshaft adjuster.

According to a first embodiment, during winding of the spring wire to a torsion spring, the inner side of the wire cross-section with less height is plunged so that thereafter the Federwindungsquerschnitt over the entire width in the radial direction has a constant height in the axial direction.

This ensures that the spring coils can lie flat against each other, whereby the spring properties, in particular better damping and less wear, are further improved.

The invention further relates to a torsion spring for a camshaft adjuster of an automotive engine, comprising a wound spring wire having a plurality of spring coils, which have a substantially equal diameter and which form a substantially cylindrical spring body, wherein the spring coils have a substantially rectangular spring wire cross-section, and two spring wire ends, each bent from the end of the foremost or rearmost spring coil substantially radially outward and each having a trapezoidal wire cross-section.

In conventional torsion springs, the spring coils often have a trapezoidal wire cross-section, with the wider side of the trapezoidal wire cross-section forming a radial inner side of the torsion spring, whereby the spring coils in loaded or unloaded condition are in line contact with the adjacent spring coil. According to one of the invention underlying knowledge resulting in worse spring properties, and it comes increasingly in this area to deformations.

The inventors have recognized this and then they have developed the torsion springs according to the invention, in which the spring coils have a rectangular spring wire cross-section. This rectangular spring wire cross-section makes it possible for the mutually axially opposite surfaces of respectively adjacent spring coils to be in surface contact with one another. This results in both an advantageous damping and improved spring properties and a smaller block size and thus a space savings by avoiding the uprising of the spring coils. In addition to this, the rectangular wire cross-section results in a particularly homogeneous voltage curve of the spring coils and the torsion spring. Furthermore, a dynamically stable torsion spring is formed, which is also more wear-resistant than a conventionally manufactured torsion spring.

The advantages and embodiments of the torsion spring correspond, in each case device-like configuration, those of the manufacturing process. These are also disclosed herein by reference in the direction of the device, without repeating it again.

The torsion spring according to the invention is suitable for various applications, in particular for a camshaft adjuster of a motor vehicle. The torsion spring is the link between a stator and a rotor of a camshaft adjuster to movably interconnect both elements.

The spring coils of uniform diameter and the cylindrical spring body formed therefrom provide uniform spring stiffness throughout the torsion spring.

With the radially outwardly bent spring wire ends with a trapezoidal cross-section, the torsion spring can be arranged so as to be slip-proof and non-rotatable relative to the stator and the rotor of a camshaft adjuster.

The torsion spring can be produced in particular by a method according to the invention.

According to a further embodiment, the trapezoidal wire cross-section of the spring wire ends has a higher outside and one Inner side of lesser height, with the upper side - viewed from the outside to the inside - slightly obliquely downward and the bottom - viewed from the outside to the inside - slightly obliquely upward.

The spring wire ends can be used by the oblique top or the oblique bottom particularly easy in mounting areas for torsion springs.

According to a further embodiment, the spring wire ends of the torsion spring in the idle state by an angle of 130 to 160 °, measured in the direction of rotation, offset from each other.

Such a torsion spring is suitable for many applications.

According to a further embodiment, the spring coils have a pitch angle of 1 to 3 °.

This allows a small block size of the torsion spring according to the invention. The torsion spring according to the invention can be used in a given space and has more spring coils and thus better spring properties than conventional torsion springs with trapezoidal spring coil cross-section.

According to a further embodiment, the spring wire ends are formed pitch-free compared to the spring coils, resulting in a particularly low block size.

According to a further embodiment, the width of the spring wire cross-section in the radial direction is greater than its height in the axial direction.

The torsion spring with the resulting rectangular wire cross-section allows a compact design. Preferably, the ratio between width and height has a value of 3: 1.

According to a further embodiment, the mutually axially opposite surfaces of respectively adjacent spring coils in the resting state of the torsion spring form a gap which has a height of 1% to 50% of the height of the wire cross section of a spring coil, resulting in advantageous spring properties.

According to a further embodiment, the mutually opposite in the axial direction surfaces of each adjacent spring coils in the idle state of the torsion spring against each other atraumfrei, resulting in a particularly compact design and a particularly low block size.

According to a further embodiment, the torsion spring has a ratio between the inner diameter of the spring coils to the outer diameter of the spring coils of the torsion spring of 0.5 to 0.7, resulting in advantageous spring properties. The torsion spring has a typical outer diameter of 35 mm, but other outer diameters are possible.

As a material for the spring wire preferably spring wire steel, in particular SiCr spring wire is used.

The torsion spring according to the invention has 3 to 7 spring coils, in particular 4 to 6 spring coils, which is particularly advantageous for use in a camshaft adjuster.

The invention also relates to a camshaft adjuster for an automotive engine comprising a stator having a substantially cylindrical stator base body with a front wall, with a rear wall and with a peripheral wall having an inwardly directed inner circumferential surface, and at least two radially from the inner circumferential surface inwardly extending stator lands, a rotor rotatably disposed in the stator having a substantially cylindrical body with an outer surface and at least two outwardly projecting rotor vanes, wherein between the inner surfaces of the front wall and the rear wall, between the stator and stator walls; Are formed webs of the stator and the rotor vanes of the rotor and between the inner circumferential surface of the stator and the outer circumferential surface of the rotor with a hydraulic medium fillable or filled pressure chambers, a formed between the stator and the rotor spring receiving space, wherein he inventive torsion spring is arranged in the spring-receiving space, that the first spring wire end rotatably connected to the stator and the second spring wire end rotatably connected to the rotor.

The camshaft adjuster according to the invention is used to change the timing or the valve opening times of intake and exhaust valves of an automotive engine during operation and thus to obtain optimized fuel consumption with simultaneous increase in power and torque.

The changing of the control times is effected by a camshaft adjuster which has a stator and a rotor rotatably positioned in the stator. The stator and the rotor are rotatably connected to each other by a torsion spring. With the rotor is a camshaft of a Motor vehicle engine connectable, which controls the timing of the valves / controls.

In operation, the phaser may be coupled via a belt to the crankshaft of the automotive engine. The term belt also includes timing belts, timing belts, V-belts, timing chains or combinations of these elements.

The adjustment of a rotational position between the stator and the rotor of a camshaft adjuster can usually take place by pressurizing a pressure space positioned between the stator and the rotor. The torsion spring according to the invention makes it possible for the rotor in the stator to be returned to its starting position when the pressure chamber is no longer subjected to a pressure or the pressure against the spring force is no longer sufficient.

The cylindrical stator body may include a plurality of stator lands to form a plurality of pressure spaces between a stator and a rotor. Preferably, the stator base body has five stator webs, which thus form five spaces, in each of which a rotor blade can be positioned. The number of stator bars usually corresponds to the number of rotor blades.

The cylindrical stator base body may be formed as a casting and has on a radial outer side of the peripheral wall or on the back of the rear wall fastening means on which a pulley or a ring gear can be fastened to the stator base body by means of the belt with the crankshaft of the Automotive engine to connect.

This allows a quick replacement of the pulley or the sprocket, without having to replace the stator base body.

In an alternative embodiment, the pulley or sprocket is integrally formed with the stator base.

As a result, the pulley or the ring gear is particularly securely connected to the stator base body.

The rotor may also be formed as a casting, wherein the thickness of the rotor may correspond to the height of the peripheral wall of the stator main body. The rotor vanes are integrally formed on the rotor and can withstand high loads. The rotor vanes on the outer circumferential surface of the rotor may also be fixed by welding, gluing or screwing.

The pressure chambers, which are formed between the stator webs and the rotor vanes, can each have at least one access, through which a hydraulic medium can be conducted into the respective pressure chamber or can be pressurized. For this purpose, the accesses can be connected to a hydraulic pump. As a hydraulic medium is particularly suitable hydraulic oil or oil with water additives.

The spring-receiving space receives a torsion spring according to the invention safely. It is advantageous that the height of the spring-receiving space corresponds to the height of a torsion spring introduced there according to the invention. This results in a compact form and reliable operation for the camshaft adjuster according to the invention.

The non-rotatable connection of the torsion spring according to the invention with the stator and with the rotor enables a safe and reliable return of the rotor to its starting position as soon as the pressure chambers are not pressurized.

An inventive camshaft adjuster has a simple, robust and compact construction and a reliable mode of operation.

All the advantages and embodiments explained above with respect to the method and the torsion spring also apply to a camshaft adjuster with such a torsion spring and will not be explained again in order to avoid repetition.

As a first embodiment, the spring-receiving space may be formed substantially cylindrical, which allows easy insertion of a torsion spring according to the invention.

According to a further embodiment, the spring receiving space in the axial direction on a first wall formed by the stator, a second wall formed by the rotor and in the radial direction an inner shell surface formed in the rotor, resulting in a simple structural design for the spring receiving space results.

According to a further embodiment, each stator web has a radially inwardly pointing end with an end face which bears against the outer circumferential surface of the rotor between two adjacent rotor vanes, whereby pressure chambers are formed in a simple manner.

According to a further embodiment, each rotor wing on a radially outwardly located end with an end face, which at the Inner lateral surface of the stator between two adjacent stator webs is applied, whereby pressure chambers are formed in a simple manner.

According to a further embodiment, the first wall formed by the stator is formed as an axially recessed portion of the rear wall of the stator, on which a torsion spring can be positioned particularly advantageous.

The recessed area is easy to produce. The recessed area may have a cylindrical shape.

According to a further embodiment, the torsion spring is arranged in the spring receiving space such that its uppermost and lowermost spring turns abut respectively on the first wall formed by the stator and on the second wall of the spring receiving space formed by the rotor. Thereby, the torsion spring is firmly positioned in the spring-receiving space and slipping or displacement of the torsion spring in the axial direction is prevented.

According to a further embodiment, the stator has a stator-side torsion spring fastening region, in which the first spring wire end is fastened or fastened in a rotationally fixed manner. As a result, the respective spring wire end can be attached to the stator easily and reliably rotationally fixed.

According to a further embodiment, the stator-side torsion spring fastening region is formed on the first wall of the spring receiving space, in particular in, on or near the peripheral wall.

According to a further embodiment, the stator-side torsion spring mounting portion is arranged on a bottom of the recessed portion radially spaced from the central axis at an inner circumferential surface formed by the recessed portion, in particular by the same distance corresponding to the distance of the spring wire end of the spring axis.

According to a further embodiment, the stator-side torsion spring fastening region is designed in the form of a substantially radially extending fastening bushing or in the form of at least two mutually spaced mounting pins or mounting wall sections forming a mounting space for a rotationally fixed attachment of a first spring wire end. This is a particularly safe way to attach the spring wire end of a torsion spring.

The fastening bush, the fastening pins or the fastening wall sections can both be arranged integrally in the stator base body, as well as subsequently attached to the stator base body.

According to a further embodiment, the width of the stator-side torsion spring fastening region in the direction of rotation corresponds to the width of the first spring wire end. This allows a particularly advantageous attachment of the spring wire end in the stator torsion spring mounting area.

According to a further embodiment, the height of the stator-side torsion spring fastening region corresponds to the height of the first spring wire end. From this, the spring wire end can be supported particularly advantageously in the torsion spring mounting area.

According to a further embodiment, the rotor has a rotor-side torsion spring mounting region in which a spring wire end is non-rotatably attached or fastened and / or which in particular at a radially spaced from the central axis, in particular spaced by the same distance, the distance of the spring wire end of whose spring axis corresponds. This is a simple and quick way to fix the spring wire end against rotation on the rotor.

According to a further embodiment, the rotor-side torsion spring fastening region is formed on the second wall of the spring receiving space, in particular in, on or near the peripheral wall.

According to a further embodiment, the rotor-side torsion spring fastening region is designed in the form of a substantially radially extending fastening bushing or in the form of at least two mutually spaced mounting pins or mounting wall sections which form a mounting space for a rotationally fixed attachment of a spring wire end. This is a particularly safe way to attach the spring wire end of a torsion spring.

The fastening bushing or the fastening pins or the fastening wall sections can both be arranged integrally in the rotor, as well as subsequently attached to the rotor.

According to a further embodiment, the width of the rotor-side torsion spring attachment region in the direction of rotation corresponds to the width of the second spring wire end. This allows a particularly secure attachment of the spring wire end in the rotor-side torsion spring mounting area.

According to a further embodiment, the height of the rotor-side torsion spring attachment region corresponds to the height of the second spring wire end. This allows a particularly secure attachment of the spring wire end in the rotor-side torsion spring mounting area.

According to a further embodiment, the angular distance between the rotor-side and the stator-side torsion spring fastening region corresponds to the angle of the spring wire ends of the torsion spring relative to one another in their rest state.

According to a further embodiment, the camshaft adjuster further comprises a stator-side support pin, which extends axially from the first wall of the spring receiving space formed by the stator in the direction of the second wall of the spring receiving space. As a result, a displacement or a displacement of the torsion spring in the camshaft adjuster according to the invention are reliably avoided.

According to a further embodiment, the stator-side support pin is arranged radially spaced from the central axis, so that the torsion spring bears against the radial inner side of at least its uppermost spring winding and thus prevents a displacement and / or diameter reduction of the torsion spring.

According to a further embodiment, the stator-side support pin is arranged opposite the rotor-side torsion-spring mounting region in the direction of rotation. This results in a particularly secure positioning of the torsion spring in the spring receiving space.

According to a further embodiment, the camshaft adjuster further comprises a rotor-side support pin which extends axially from the second wall of the spring receiving space formed by the rotor in the direction of the first wall of the spring receiving space. As a result, a displacement or a displacement of the torsion spring in the camshaft adjuster according to the invention are reliably avoided.

According to a further embodiment, the rotor-side support pin is arranged radially spaced from the central axis, so that the torsion spring bears against the radial inner side of at least its lowermost spring winding and thus prevents a displacement and / or diameter reduction of the torsion spring.

According to a further embodiment, the rotor-side support pin is arranged opposite to the stator-side torsion spring attachment region in the direction of rotation.

The invention further relates to a motor vehicle engine having at least one camshaft adjuster according to the invention.

This results in a particularly efficient motor vehicle engine, which is economical in consumption and offers good power delivery.

All of the advantages and embodiments discussed above with respect to the method, the torsion spring, and the phaser also apply to an automotive engine having such a phaser and will not be discussed again to avoid repetition.

The invention will be described in more detail below with reference to the embodiments schematically shown in the accompanying figures. Showing:

1 a perspective view obliquely from above on a torsion spring with its two radially outwardly bent spring wire ends, according to an embodiment of the present invention;

2 a side view of the torsion spring 1 ;

3 a perspective sectional view along a plane passing through the spring axis section plane AA of the torsion spring from the 1 and 2 in which the wire cross section of the spring coils can be seen;

4 a plan view of the torsion spring of 1 to 3 ;

5 a schematic representation of a trapezoidal wire cross section of a spring wire end of the torsion spring from the 1 to 4 ;

6 a schematic representation of a rectangular wire cross section of a spring coil of the torsion spring from the 1 to 4 ;

7 a perspective view of a stator for a phaser with a clear view of a rotor-receiving space and a torsion spring receiving space, according to an embodiment of the present invention;

8th a perspective view of a rotor for a phaser, wherein a facing away from the viewing direction torsion spring receiving space of the rotor is shown by dashed lines; and

9 a perspective view of a camshaft adjuster with the stator 7 , With out of the rotor 8th and with the torsion spring positioned in the torsion spring accommodating space 1 to 4 , according to an embodiment of the present invention.

1 shows a torsion spring according to the invention 2 , which was produced by a method according to the invention from a trapezoidal spring wire. The torsion spring 2 has a cylindrical spring body 4 as well as two spring wire ends 8th . 10 on. The spring body 4 , which is formed by the spring coils, extends around one in 1 vertically extending center or spring axis and has a height above the spring body 4 constant diameter.

The spring wire ends 8th . 10 are arranged to each other in the rest position of the torsion spring at an angle of 130 to 160 ° measured in the radial direction and extend radially from the central axis of the spring body 4 path. The spring wire ends 8th serve to the torsion z. B. on a rotor and a stator rotatably to position.

The spring wire ends 8th . 10 have a trapezoidal wire cross section, wherein the trapezoidal wire cross section is identical to the trapezoidal spring wire.

The spring body 4 exemplifies four spring coils 12 each having a rectangular wire cross-section, wherein number of spring coils 12 , depending on the application. The spring coils 12 have a radially inwardly directed inner side with an inner diameter and a radially outwardly directed outer side with an outer diameter, wherein the inner diameter and the outer diameter may be different and adapted to the application.

The spring coils 12 are arranged parallel to each other, wherein adjacent spring coils are arranged with a small gap to each other, which corresponds to about 20% of the height of a spring coil. Alternatively, the respective adjacent spring coils 12 also abut one another gap-free, or a gap corresponding to a height between 1% and 50% of the height of a spring coil, may be arranged therebetween.

The spring coils 12 have a pitch angle that is in a range between 1 and 10 °, in particular between 1 and 3 °.

A torsion spring 2 whose spring turns have only a slight slope and adjacent spring coils abut gap-free, or between which only a small gap is present, have only a small block size.

The torsion spring 2 can be used in different fields of application, preferably in an automotive engine and in this particular in a camshaft adjuster.

2 shows a side view of the torsion spring 2 , Here are the four spring coils 12 each having a rectangular cross-section, between the respective adjacent spring coils 12 formed spaces and the radially outwardly bent spring wire ends 8th and 10 to recognize well with each trapezoidal cross-section.

It is also easy to see that the inner sides of the spring wire ends pointing towards the observer 8th and 10 have a lower height than the observer away directed outer sides of the spring wire ends 8th and 10 ,

In the sectional view of 3 is the trapezoidal shape of the cross section of the spring wire end 8th and the rectangular shape of the cross section of the spring coils 12 clearly visible.

You can also see in 3 that the radial width of the spring coils 12 about twice as large as the axial height of the same.

In the transition area between the spring wire end 8th and the topmost spring coil 12 the trapezoidal cross section turns into a rectangular cross section.

In the plan view of the torsion spring 2 in 4 is good to see that the spring wire ends 8th and 10 each from the end of the lowermost or uppermost spring coil 12 are bent radially outward and extend radially outward. The spring wire ends 8th . 10 can at an angle between 80 ° and 100 °, in particular at an angle of 90 °, of the spring coils 12 starting to be bent radially outward. The spring wire ends 8th and 10 lie in the embodiment at an angle of about 130 ° to 160 °, in particular from 140 ° to 150 °, measured in the direction of rotation, to each other. Of course, the spring wire ends 8th and 10 be arranged at a different angle to each other.

It is also good to see that the inner diameter and outer diameter of the spring coils 12 are constant. The ratio of inner diameter to outer diameter is preferably between 0.5 and 0.7. Certainly, another diameter ratio is possible.

5 shows the trapezoidal cross-section of the spring wire ends 8th and 10 , with the higher outside arranged on the left side and the lower side arranged on the right side, with the first longitudinal side running slightly obliquely downwards from the outside to the inside and with the slightly inclined upwards running side viewed from the outside to the inside again second longitudinal side of the spring wire end 8th respectively. 10 ,

6 shows the rectangular spring wire cross-section of an exemplary spring coil 12 in which the radial width of the spring coil 12 about 3 to 4 times the axial height thereof corresponds.

In the manufacture of the torsion spring 2 is the first step, a spring wire with trapezoidal wire cross-section 3 fed to a spring winding machine. The spring wire can from a supply roll with already manufactured spring wire with trapezoidal wire cross section 3 can be fed or the spring wire can be pulled out of a spring wire manufacturing machine and introduced directly into the spring winding machine. The side of the wire cross section, which rests on a winding cylinder of the spring winding machine, has a lower height and the side of the wire cross section with a larger height is not in contact with the winding cylinder. The side of the wire cross-section of lesser height forms a radial inside 6 the later spring winding 12 and the side of the wire section of greater height forms a radial outside 7 the later spring winding 12 ,

The first spring wire end 8th can be so inserted into the spring winding machine that a short extension of the spring wire 3 tangentially protrudes beyond the winding cylinder with a trapezoidal wire cross-section. The short extension can first be bent in the opposite direction to the winding cylinder, whereby the first spring wire end with trapezoidal wire cross-section 8th is formed. Then the first spring wire end becomes 8th held in the spring winding machine so that the spring wire 3 by winding about the winding cylinder to a substantially cylindrical torsion spring 2 with spring coils 12 is wound, with the first spring wire end 8th maintains its shape and alignment. When winding, the radial inside 6 the torsion spring 2 so upset that the spring coils 12 obtained a rectangular wire cross-section.

The cutting to length of the wound spring wire 3 takes place with a small distance in front of the winding cylinder in the running direction of the spring wire 3 so that the spring wire 3 between Ablängbereich and winding cylinder is linear. Now, the linear spring wire portion thus formed in the radial direction of the winding cylinder and thereby also of the spring coils 12 bent away and forms the second spring wire end with trapezoidal wire cross-section 10 ,

The method of the present invention has the advantage that it is quick and easy to perform and that the spring wire 3 is bent in one direction only during the production per area. As a result, stresses in the spring wire 3 minimized and the life of a torsion spring produced according to the invention 2 elevated. Furthermore, the torsion springs according to the invention 2 improved spring properties and have a very compact design.

7 shows a perspective view of a stator 14 a camshaft adjuster 60 with a clear view of a rotor receiving space 20 and a torsion spring receiving space.

8th shows a perspective view of a rotor 36 a camshaft adjuster 60 wherein a direction away from the viewing direction facing torsion spring receiving space of the rotor is shown by dashed lines.

9 shows a perspective view of a camshaft adjuster 60 with the stator 14 , with the rotor 36 and with the torsion spring positioned in the torsion spring receiving space 2 ,

The stator 14 has a substantially cylindrical stator base body 16 on. The stator base 16 is through a front wall, not shown, a rear wall 17 and a peripheral wall 18 educated. The front wall, not shown, may be formed in a conventional manner on an end face of the peripheral wall 18 , which points in the axial direction forward, be attached.

The front wall, the back wall 17 and the peripheral wall 18 Together they form a rotor-receiving space 20 ,

From one through the peripheral wall 28 formed and radially inwardly directed inner circumferential surface 19 extend five equidistant to each other arranged stator webs 21 radially inwardly to a central axis of the stator 14 ,

Of course, fewer or more stator webs 21 on the inner circumferential surface 19 to be ordered.

Every stator bridge 21 has two side surfaces, the lateral pressure chamber boundary surfaces 23 and 24 form. Each side surface has in the circumferential direction to one of these opposite side surface of a stator adjacent in the direction of rotation Stator 21 ,

Every stator bridge 21 forms one to the central axis of the stator 14 pointing face 22 out. The diameter of the faces 22 form, is less than the diameter of the inner circumferential surface 19 , and chosen so that the end faces 22 against an outer circumferential surface 41 of the rotor 36 issue.

The rotor 36 has a cylindrical rotor body 38 with a front side 39 and an invisible back 40 on. The cylindrical rotor body 38 has an outer circumferential surface 41 radially from a central axis of the rotor 36 points outward and from which in this embodiment, five rotor blades 42 extend radially outward.

Of course, the rotor 36 also more or less rotor-wing 42 exhibit.

The rotor wings 42 each form two side surfaces and a wing end face 44 from, wherein each side surface to an opposite side surface of a rotor blade adjacent in the rotational direction 42 shows and the wing face 44 radially outward to the inner circumferential surface 26 of the stator 14 shows and rests against this. The side surfaces of the rotor wing 42 are as pressure chamber boundary surfaces 46 . 48 educated.

When positioning the rotor 36 in the stator 14 , as in 9 shown, each form two stator webs 21 , a rotor wing 42 , the inner lateral surface 19 of the stator 14 , the front of the back wall 17 of the stator 14 , the back of the front wall of the stator 14 and the outer circumferential surface 41 of the rotor 36 together a front pressure chamber 62 and a rear pressure chamber 64 from, wherein the pressure chambers can be filled or filled with a hydraulic medium. The two pressure chambers 62 and 64 are in the direction of rotation spatially by the rotor wing 42 separated.

The front pressure chamber 62 is from the pressure chamber boundary 23 of the stator bridge 21 and the pressure space boundary surface 46 of the rotor wing 42 in the direction of rotation, from the back wall 17 and the front wall of the stator 14 in the axial direction and from the outer circumferential surface of the rotor 36 and the inner circumferential surface of the stator 14 limited in the radial direction.

The rear pressure chamber 64 is from the pressure chamber boundary 48 of the rotor wing 42 and the pressure space boundary surface 24 of the stator bridge 21 in the direction of rotation, from the back wall 17 and the front wall of the stator 14 in the axial direction and from the outer circumferential surface of the rotor 36 and the inner circumferential surface of the stator 14 limited in the radial direction.

Every stator bridge 21 has the largest width in the direction of rotation directly on the inner circumferential surface 19 the peripheral wall 18 on. The width of the stator bridge 21 decreases constantly from the inner circumferential surface 19 in the direction of the central axis of the stator 14 , The width of each stator bar 21 at its from the inner lateral surface 19 the peripheral wall 18 farthest point is 50% or less of the width immediately on the peripheral wall 18 ,

The length of the stator webs 21 to the the stator webs 21 from the inner circumferential surface 19 the peripheral wall 18 to the central axis of the stator 14 range, corresponds to about 10% to 20% of the diameter of the stator 14 , The length of the stator webs 21 is dependent on the diameter of the outer circumferential surface 41 of the rotor 36 at the the stator webs 21 with their faces 22 issue.

Every rotor wing 42 has a smaller width in the direction of rotation near the outer circumferential surface 41 as the width away from the outer circumferential surface 41 on. The wing end faces 44 form a diameter which is larger than the diameter of the outer circumferential surface 41 , and the diameter is chosen so that the wing end faces 44 on the inner circumferential surface 19 the peripheral wall 18 of the stator 14 abut, so that no liquid between the wing end face 44 and the inner circumferential surface can flow.

The length of the side surfaces of the stator webs 21 corresponds to the length of the side surfaces of the rotor vanes 42 ,

In the back wall 17 of the stator 14 is a recessed cylindrical area 25 formed, which has a smaller diameter than the diameter of the end faces 22 the stator webs 21 ,

A through the recessed cylindrical area 25 Trained ground forms a first wall for a torsion spring receiving space 66 out. The recessed cylindrical area 25 becomes radially through an inner circumferential surface 26 limited.

In the rotor 36 is also provided a cylindrical recess extending axially from the back 40 of the rotor 36 towards the front 39 of the rotor 36 extends and forms a bottom having a second wall of the spring receiving space 66 represents. The cylindrical recess of the rotor 36 forms an inner circumferential surface, which together with the inner circumferential surface 26 of the stator 14 a spring-receiving space 66 limited in the radial direction.

The cylindrical recess may have a depth of 40% to 80% of the height of the rotor 36 exhibit. Preferably, the depth corresponds to the cylindrical recess of the rotor 36 together with the Depth of the cylindrical area 25 of the stator 14 the height of the torsion spring 2 ,

Central in the recessed cylindrical area 25 of the stator 14 is a camshaft recess 34 arranged to perform a camshaft. Central in the cylindrical recess of the rotor 36 is a camshaft mounting recess 58 arranged, in which a camshaft of an automotive engine can be used and fastened.

A torsion spring attachment area 30 of the stator 14 is formed in the form of two spaced-apart fastening pins extending from the inner circumferential surface 26 on the bottom of the recessed cylindrical area 25 radially some distance in the direction of the central axis of the stator 14 extend. The distance of the fastening pins corresponds to the width of a spring wire end, not shown. The torsion spring mounting area 30 is designed so that a spring wire end is rotatably inserted into these. The torsion spring mounting area 54 takes a spring wire end against rotation. A height of the fixing pins is selected so that the height of the fixing pins corresponds to the height of the spring wire end. The torsion spring mounting portion may also be formed in the form of a mounting bush or a mounting wall portion.

From the bottom of the recessed cylindrical area 25 extends a radially spaced from the central axis support pin 32 in the axial direction from the bottom of the recessed cylindrical portion 25 path. The support pin 32 is arranged so that one in the recessed cylindrical area 25 placeable torsion spring 2 with the inside of its spring coils 3 on the support pin 32 is applied. The torsion spring mounting area 30 and the support pin 32 are at an angle of 70 ° to 100 °, in particular at an angle of 90 °, measured in the direction of rotation, arranged to each other.

The backside 40 of the rotor 36 has a first stator abutment surface 50 on, located on the back 40 of the rotor 36 radially from outside the cylindrical recess to the wing end faces 44 extends and on the rotor abutment surface 27 of the stator 14 lies flat. The front 39 of the rotor 36 Also forms a contact surface, which at the back of the front wall of the stator 14 can be present.

On the bottom of the cylindrical recess of the rotor 36 extend from the inner circumferential surface radially in the direction of the central axis two spaced apart mounting pins, which a torsion spring mounting portion 54 form. The distance of the fixing pins is selected so that it corresponds to the width of the trapezoidal wire cross section of a spring wire end. The torsion spring mounting area 54 takes a spring wire end against rotation. The height of the mounting pins is chosen so that it corresponds to the height of the spring wire end. Of course, the torsion spring mounting area 54 also be designed as a mounting bush or as a mounting wall portion.

From the bottom of the cylindrical recess extends towards the back 40 of the rotor 36 a support pin 56 which is spaced radially from the central axis such that the spring coils 3 the torsion spring placed in the cylindrical recess 2 with its inside on this support pin 56 issue. The torsion spring mounting area 54 and the support pin 56 are at an angle of 70 ° to 100 °, in particular at an angle of 90 °, measured in the direction of rotation, arranged to each other.

On an outer circumferential surface of the peripheral wall 18 of the stator 14 that is radial from the central axis of the stator 14 pointing to the outside, or at the back of the back wall 17 of the stator 14 is a pulley, not shown, or not shown sprocket attachable or attachable, with which the stator 14 can be driven and synchronized with the speed of a crankshaft of a motor vehicle engine.

The camshaft adjuster 60 includes the stator 14 , the torsion spring 2 and the rotor 36 , which are arranged concentrically with each other.

The stator is the torsion spring 2 with her first spring wire end 8th in the stator-side torsion spring mounting portion 30 arranged and rotationally fixed with the stator 14 connected. The inside of the spring coils 12 the torsion spring 2 lies on the side of the support pin 32 at. Rotor side is the torsion spring 2 with her second spring wire end 10 in the rotor-side torsion spring mounting area 54 arranged and rotationally fixed with the rotor 36 connected. The inside of the spring coils 12 the torsion spring 2 lies at the support pin 56 of the rotor 36 at.

The recessed cylindrical area 25 of the stator 14 , the cylindrical recess in the rotor 36 and through the cylindrical area 26 of the stator 14 and through the cylindrical recess of the rotor 36 , which are aligned with each other, formed inner circumferential surface together form the spring receiving space 66 in which the torsion spring 2 is included.

The height of the rotor 36 and the height of the torsion spring 2 are chosen so that the stator contact surface 50 of the rotor 36 at the rotor contact surface 27 of the stator 14 liquid-impermeable rests while the front 39 of the rotor 36 the same height as the front of the peripheral wall 18 of stator 14 having. Then, a front wall, not shown, of the stator 14 so on the front side of the peripheral wall 18 be attached to the front wall of the stator 14 on the front side 39 of the rotor 36 liquid impermeable.

In a starting position of the camshaft adjuster 60 is the rotor 36 so in the stator 14 arranged that the pressure space boundary surface 46 of the rotor wing 42 at a small distance, in particular in direct contact, to the pressure chamber boundary surface 23 the stator webs 21 is. Here is the torsion spring 2 relaxed and the spring wire ends 8th and 9 are like in 1 with an angle of 130 ° to 160 °, measured in the direction of rotation, aligned.

Of course, the torsion spring 2 also biased in the camshaft adjuster 60 be fitted to a higher restoring force of the torsion spring 2 during operation of the camshaft adjuster 60 to ensure.

In the 9 take the spring wire ends 8th and 10 to each other an angle between 70 ° to 90 ° in the starting position of the camshaft adjuster 60 one.

During operation, the camshaft adjuster 60 be driven with a belt to one in the phaser 60 To rotate fixed camshaft and thus to control the opening times of the intake and exhaust valves of a cylinder in an automotive engine or regulate. In the event that the vehicle engine needs to retrieve higher engine power, a hydraulic medium in the front pressure chamber 62 subjected to additional pressure by a pump or the like. This causes the rotor 36 together with the camshaft against the restoring force of the torsion spring 2 in the direction of rotation in the stator 14 is twisted, resulting in a changed timing of the intake and exhaust valves. As soon as the higher engine power is no longer necessary, the front pressure chamber 62 Relieved from the applied hydraulic pressure and the force of the torsion spring 2 guides the rotor 36 together with the camshaft back to the original position in the stator 14 back, which again set the original timing of the intake and exhaust valves.

Using the torsion spring 2 is particularly advantageous because it is the torsion spring 2 is a mechanical adjustment, which is simple in design, but still works reliably and is independent of hydraulic, pneumatic and electrical controls / regulations.

LIST OF REFERENCE NUMBERS

2

torsion spring

3

Spring wire with rectangular wire cross-section

4

spring body

6

radial inside

7

radial outside

8th

first spring wire end with trapezoidal wire cross section

10

second spring wire end with trapezoidal wire cross section

12

Spring coil with rectangular wire cross-section

14

stator

16

Stator assembly base

17

rear wall

18

peripheral wall

19

Inner surface area

20

Rotor receiving space

21

Stator web

22

face

23

Pressure chamber boundary surface

24

Pressure chamber boundary surface

25

recessed cylindrical area

26

Inner surface area

27

Rotor-bearing surface

28

Torsion spring-contact surface

30

Torsion spring mounting region

32

support pin

34

camshafts recess

36

rotor

38

Rotor base body

39

front

40

back

41

Outer casing surface

42

Rotor wing

44

Wing face

46

Pressure chamber boundary surface

48

Pressure chamber boundary surface

50

Stator contact surface

52

Torsion spring-contact surface

54

Torsion spring mounting region

56

support pin

58

Camshaft mounting recess

60

Phaser

62

front pressure chamber

64

rear pressure chamber

66

Spring receiving space

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102010063706 [0002]

Claims (13)

Method for producing torsion springs ( 2 ) for a camshaft adjuster ( 60 ) of an automotive engine, comprising the following steps: feeding a spring wire ( 3 ) with a trapezoidal wire cross-section to a spring winding machine, so that the side of the wire cross-section of greater height, which the radial outer side of the later spring coils ( 12 ), lies on the outside and the side of the wire cross-section of lesser height, which the radial inside of the later spring coils ( 12 ) lies inside; Winding the spring wire ( 3 ) in the spring winding machine to a substantially cylindrical torsion spring ( 2 ) with spring coils ( 12 ) and two from the end of the uppermost or lowermost spring coil substantially radially outwardly bent spring wire ends ( 8th . 10 ), so that the spring coils ( 12 ) a rectangular winding cross section and its two spring wire ends ( 8th . 10 ) each have a trapezoidal wire cross-section; and cutting the wound spring wire ( 3 ) in individual torsion springs ( 2 ). Method according to claim 1, wherein during winding of the spring wire ( 3 ) to a torsion spring ( 2 ) the inner side of the wire cross-section of the spring coils is plunged at a lower height so that thereafter the wire cross-section of the spring coils over the entire thickness in the radial direction has a constant height in the axial direction; and / or wherein the two spring wire ends ( 8th . 10 ) have a trapezoidal wire cross-section. Torsion spring ( 2 ) for a camshaft adjuster ( 60 ) of a motor vehicle engine comprising: a coiled spring wire ( 3 ) with several spring coils ( 12 ), which have a substantially equal diameter and a substantially cylindrical spring body ( 4 ), wherein the spring coils ( 12 ) have a substantially rectangular spring wire cross-section; and two spring wire ends ( 8th . 10 ), each from the end of the uppermost or lowermost Federwindung ( 12 ) are bent substantially radially outwards and each having a trapezoidal wire cross-section. Torsion spring ( 2 ) according to claim 3, wherein the trapezoidal wire cross section of the spring wire ends ( 8th . 10 ) has a higher outer side and an inner side of lesser height, wherein the upper side - viewed from the outside to the inside - slightly obliquely downward and the bottom - viewed from the outside to the inside - slightly obliquely upward. Torsion spring ( 2 ) according to claim 3, wherein the mutually axially opposite surfaces of respectively adjacent spring coils ( 12 ) in the resting state of the torsion spring ( 2 ) form a gap of a height of 1% to 50% of the height of the wire cross-section of a spring coil ( 12 ) having; or wherein the mutually axially opposite surfaces of each adjacent spring coils ( 12 ) in the resting state of the torsion spring ( 2 ) abut one another without gaps. Camshaft adjuster ( 60 ) for a motor vehicle engine, comprising: a stator ( 14 ) with a substantially cylindrical stator base body ( 16 ) with a front wall, with a rear wall ( 17 ) and with a peripheral wall ( 18 ), which has an inwardly directed inner circumferential surface ( 19 ), and at least two of the inner circumferential surface ( 19 ) radially inwardly extending stator webs ( 21 ); a rotatable in the stator ( 14 ) arranged rotor ( 36 ) with a substantially cylindrical base body ( 38 ) with an outer circumferential surface ( 41 ) and with at least two rotor blades ( 42 ); being between the inner surfaces ( 19 ) of the front wall and the rear wall ( 17 ), between the stator bars ( 21 ) of the stator ( 14 ), and the rotor blades ( 42 ) of the rotor ( 36 ) and between the inner surface ( 19 ) of the stator ( 14 ) and the outer circumferential surface ( 41 ) of the rotor ( 36 ) with a hydraulic medium fillable or filled pressure chambers ( 62 . 64 ) are formed; one between the stator ( 14 ) and the rotor ( 36 ) formed spring receiving space ( 66 ); a torsion spring ( 2 ) according to one of claims 3 to 5 in the spring receiving space ( 66 ) is arranged such that the first spring wire end ( 8th ) rotatably with the stator ( 14 ) and the second spring wire end ( 8th ) rotatably with the rotor ( 36 ) connected is. Camshaft adjuster ( 60 ) according to claim 6, wherein the spring receiving space ( 66 ) in the axial direction through the stator ( 14 ) formed first wall, one through the rotor ( 36 ) formed second wall and in the radial direction has an inner shell surface formed in the rotor; and / or wherein each stator bridge ( 21 ) has a radially inwardly located end with an end face on the outer circumferential surface ( 41 ) of the rotor ( 36 ) abuts between two adjacent rotor vanes; and / or wherein each rotor wing ( 41 ) has a radially outwardly located end with an end face, which on the inner circumferential surface ( 19 ) of the stator ( 14 ) between two adjacent stator bars ( 21 ) is present; and or where the through the stator ( 14 ) formed first wall as an axially recessed area ( 24 ) of the rear wall ( 17 ) of the stator ( 14 ) is trained. Camshaft adjuster ( 60 ) according to claim 6 or 7, wherein the torsion spring ( 2 ) so in the spring-receiving space ( 66 ) is arranged that its top and bottom spring coil ( 12 ) each at the by the stator ( 14 ) formed first wall or at the by the rotor ( 36 ) formed second wall of the spring-receiving space ( 66 ) is present. Camshaft adjuster ( 60 ) according to one of claims 6 to 8, wherein the stator ( 14 ) a stator-side torsion spring mounting area ( 30 ), in which the first spring wire end ( 8th ) is rotatably attached or fastened; and / or which is radially spaced from the central axis, in particular by the same distance, which is the distance of the first spring wire end ( 8th ) corresponds to its spring axis; and / or wherein the stator-side torsion spring mounting area ( 30 ) on the first wall of the spring receiving space ( 66 ), in particular in, on or near the peripheral wall of the spring receiving space ( 66 ) is trained. Camshaft adjuster ( 60 ) according to claim 9, wherein the stator-side torsion spring mounting area ( 30 ) in the form of a substantially radially extending mounting bushing or in the form of at least two mutually spaced mounting pins or mounting wall sections is formed, which has a mounting space for a rotationally fixed attachment of a first spring wire end ( 8th ) train. Camshaft adjuster ( 60 ) according to one of claims 9 or 10, wherein the width of the stator-side torsion spring mounting area ( 30 ) in the direction of rotation of the width of the first spring wire end ( 8th ) corresponds; and / or wherein the height of the stator-side torsion spring mounting area ( 30 ) the height of the first spring wire end ( 8th ) corresponds. Camshaft adjuster ( 60 ) according to one of claims 6 to 11, wherein the rotor ( 36 ) a rotor-side torsion spring mounting area ( 54 ), in which a spring wire end ( 8th ) is fastened or fastened; and / or spaced radially from the central axis, in particular spaced by the same distance, which is the distance of the second spring wire end ( 10 ) corresponds to its spring axis; and / or wherein the rotor-side torsion spring mounting area ( 54 ) on the second wall of the spring receiving space ( 66 ), in particular in, on or near the peripheral wall of the spring receiving space ( 66 ) is trained; and / or wherein the rotor-side torsion spring mounting area ( 54 ) in the form of a substantially radially extending mounting sleeve or in the form of at least two mutually spaced mounting pins or mounting wall sections is formed, which has a mounting space for a rotationally fixed attachment of a spring wire end ( 8th ) train; and / or wherein the width of the rotor-side torsion spring mounting area ( 54 ) in the direction of rotation of the width of the second spring wire end ( 10 ) corresponds; and / or wherein the height of the rotor-side torsion spring mounting area ( 54 ) the height of the second spring wire end ( 10 ) corresponds. Camshaft adjuster ( 60 ) according to one of claims 6 to 12, further comprising a stator-side support pin ( 32 ) extending from the first wall of the spring receiving space ( 66 ) in the axial direction of the second wall of the spring receiving space ( 66 ) extends; and / or wherein the stator-side support pin ( 32 ) is arranged radially spaced from the central axis, so that the torsion spring ( 2 ) with the radial inside ( 6 ) at least its uppermost spring turn ( 12 ) is applied thereto and a displacement and / or diameter reduction of the torsion spring ( 2 ) is prevented; and / or wherein the stator-side support pin ( 32 ) the rotor-side torsion spring mounting area ( 54 ) is arranged opposite in the radial direction; and / or further comprising a rotor-side support pin ( 56 ), which differs from that through the rotor ( 14 ) formed second wall of the spring receiving space extends axially in the direction of the first wall of the spring receiving space; and wherein the rotor-side support pin ( 56 ) is arranged radially spaced from the central axis, so that the torsion spring ( 2 ) with the radial inside ( 6 ) at least its lowest spring turn ( 12 ) is applied thereto and a displacement and / or diameter reduction of the torsion spring ( 2 ) is prevented; and / or wherein the rotor-side support pin ( 56 ) the stator-side torsion spring mounting portion ( 30 ) is arranged opposite in the radial direction.

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