EP2466117A1 - Starter device for a combustion engine - Google Patents

Abstract

The starter (100) has a pulley (11) rotationally movable by a traction unit (13) i.e. rope, for producing drive torque for an engine shaft. The pulley is connected to with a driver link (15) over an attenuation spring (14) i.e. torsion spring, that is made of a spring wire. The pulley is twisted against the driver link under torsion of the spring until the twist of a stop element (16) against a thrust ring is limited. The stop element and/or the ring are made of material exhibiting high strength than that of the materials of the driver link and/or the pulley. The thrust ring is made of metal.

Description

The present invention is directed to a starting device for an internal combustion engine with a rotatably mounted in a housing sheave, which is for generating a driving torque for a motor shaft by means of a starter handle via a traction means in rotary motion and connected via a formed of a spring wire damping spring with a driver member , By means of which the drive torque is transferable to the motor shaft for starting the internal combustion engine, wherein under torsion of the damping spring, a rotation of the pulley against the driver member is allowed to reach the limit of rotation, a stop element against a counter-stop.

STATE OF THE ART

pamphlet DE 203 01 182 U1 shows a generic starting device for an internal combustion engine, and a Auswerfergriff is connected to a traction means, which is rolled up on a pulley. When a user pulls on the ejector handle, the pulley is rotated by the traction means, and the rotation is transmitted via a damping spring to a driver member, by means of which the drive torque is transferable to the motor shaft for starting the internal combustion engine.

If a user pulls on the starter handle and thus puts the pulley into rotation, the angle of rotation of the pulley may already deviate from the angle of rotation of the driver member. If an internal combustion engine is started by rotating the motor shaft by applying a torque, then the reciprocating piston principle of the internal combustion engine results in an uneven torque curve when the motor shaft rotates. In the compression phase, an in-cylinder piston, the torque increases, and thus acts against the drive torque. In the decompression phase, however, the rotational movement of the motor shaft is supported, and when turning the motor shaft thus results in a periodic force curve with corresponding force peaks. Consequently, this means that the applied torque to the motor shaft is subject to strong fluctuations, which on the pulley and thus can also be transferred to the ejector handle. In order to avoid or at least reduce the transmission of the force peaks from the driver member, which is connected to the motor shaft when starting the engine with the motor shaft, the damping spring is provided which allows a torsion between the pulley and the driver member to the driver member at least in to be able to turn a predetermined angular range against the pulley. Consequently, the force peaks are transferred only reduced to the pulley.

In order to limit the rotation of the driver member relative to the sheave, and in order to avoid damage to the damping spring by overuse, a stop element is provided which can come against a counter-stop to the plant, whereby the maximum angle of rotation of the driver member relative to the sheave is limited, so Also, the maximum torsion of the damping spring is limited.

At a fraction of the damping spring, but also in an elastic overuse of the damping spring, due to the force peaks of the internal combustion engine acting on the stop of the stop element against the counter-stop a significant force. This can have the consequence that the stop element or the counter-stop member mechanically failed, in particular it can lead to breakage of the stop element or the counter-stop element.

To increase the load capacity of the stop, two stop elements may be provided which are arranged on the driver member diametrically opposite each other. Consequently, two stops may abut against a respective counter-abutment to allow for maximum load capacity to transmit torque from the sheave to the dog member, for example, if the damper spring is broken. Disadvantageously, however, halves the maximum angle of rotation, since the attacks are offset by a maximum of 180 ° to each other.

If a fraction of the damping spring, it is desirable to be able to operate the starting device at least temporarily, despite broken damper spring. Such emergency operation of the starting device in case of a defect of the damping spring can be done by a torque of the pulley is transmitted to the driver member directly on the stop element and the counter-stop element. If the stop member against the counter-stop to the system, a torque can be transmitted from the pulley to the driver member in the same way, but without attenuating the force peaks from the engine to the sheave. However, if the internal combustion engine is started with a defective damping spring, the force peaks can cause a mechanical breakage of the stop element and / or the counter-stop, and it is desirable to avoid this breakage.

It is therefore the object of the present invention to provide a starting device for an internal combustion engine, which enables a high operational readiness of the starting device, in particular in the case of a defect of the damping spring.

This object is achieved on the basis of a starting device for an internal combustion engine according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous developments of the invention are specified in the dependent claims.

DISCLOSURE OF THE INVENTION

The invention includes the technical teaching that the stop element and / or the counter-stop are formed from a material having a higher strength than the material of the driver element and / or as the material of the sheave.

The invention is based on the idea of forming the stop element and / or the counter-stop of a material which differs from the material of the driver element and / or the material of the sheave. It is particularly advantageous to produce the driver member and / or the sheave from a plastic material, in particular in an injection molding process. The thus to be processed plastic materials have only a low strength, so it can come to the problem described above, that the stop element and / or the counter-stop undergoes a mechanical break, if a defect of the damping spring, the force peaks when starting the engine directly from the driver member in the pulley are transmitted. With the invention Choice of materials, the driver member and / or the sheave can still be made of a low-cost plastic material, the stop element and / or the counter-stop may be formed of a different material, in particular a material of higher strength, so that the failure of the stop element and / or the counter-attack even when the force peaks occur no damage.

According to an advantageous embodiment, the stop element may be formed of a metallic material, in particular of a steel material, wherein in particular the driver member and / or the sheave are formed of a plastic material. Likewise, the counter-stop as an insert element made of a material of high strength, in particular as an insert element of a metallic material, be formed and used in the sheave. Preferably, both the stop element for the driver member and the counter-stop for the sheave can be encapsulated by plastic injection molding, so that the stop element and / or the counter-stop are already inserted into an injection mold when the plastic material is injected into the mold.

According to a possible embodiment, the stop element may be arranged on the driver element, and protrude from a pulley facing surface of the driver element, in particular the stop element may be formed as a pin element or as a bolt element and extending from the pulley facing surface of the driver member in the direction of the sheave out , In the pulley, a guide groove may be introduced, in which the stop element is guided, wherein the counter-stop engages in the guide groove. Thus, the maximum rotation of the driver member relative to the sheave be limited by the stop member abuts against the counter-stop. Alternatively it is possible in the same way to provide the stop element in the pulley, and the guide groove can be introduced in the driver member.

Advantageously, the spring wire of the damping spring may have two ends, and a first end may engage with the driver member and a second end may engage the sheave, with the counter-abutment is formed from the spring wire of the damping spring, which in particular has a metallic material of high hardness. According to the invention, the damping spring on the one hand fulfills the damping function between the pulley and the driver member, on the other hand, the damping spring forms the counter-stop, to which the stop member can strike against the pulley to limit the rotation of the driver.

In particular, the counter-stop can be formed from the second end of the spring wire of the damping spring, which is in engagement with the sheave. The second end of the spring wire of the damping spring may have a curved shape, wherein the curved shape is enclosed with a first portion in a receptacle of the pulley for engagement in this and protrudes with a second portion of the recording of the pulley in the direction of the driver. The part of the second end, which is enclosed in the receptacle of the sheave, on the one hand fixes the damping spring in the sheave, so that a torque can be applied by the sheave to the damping spring, and furthermore the first section of the second end enclosed in the receptacle meets Fixing the second end, so that the second portion which protrudes from the receptacle, is rigidly connected to the pulley to form the counter-stop.

The curved shape of the second end of the spring wire of the damping spring may have an S-shape, a C-shape or an inverted U-shape. In this case, the second end of the spring wire of the damping spring may extend with its curved shape in a plane, in particular, the S-shape, the C-shape or the inverted U-shape extend in a plane, wherein the damping spring has a central axis, the lies in the plane of the second end. Thus, the plane is defined by the central axis and an axis orthogonal to the central axis, and the second end of the spring wire extends approximately perpendicularly out of the body of the damper spring. The second end of the spring wire can have any curved shape, and the S-shape, the C-shape or the inverted U-shape in each case only one possible advantageous embodiment, on the one hand to form the first portion, in the recording of the pulley can be used, and on the other hand to form the second section, the counter-stop serves for the stop element. The inverted U-shape describes a "U", and the open side of the "U" is inserted into the receptacle, so that protrudes from the receptacle as a second section only a loop of the spring wire to form a rigid, load-bearing counter-attack.

In order to form the stop element and / or the counter-stop of a material which has a higher strength than the material of the driver element and / or as the material of the sheave, the stop element and / or the counter-stop can only by a material of higher strength, for example, by a metallic material to be reinforced. For example, the stop element and / or the counter-stop can be formed integrally with the material of the driver element and / or with the material of the sheave, and the stop element and / or the counter-stop is merely reinforced with a material of higher strength, for example by a metal core, or through a metal tower.

BRIEF DESCRIPTION OF THE DRAWINGS

• Figur 1 ein Ausführungsbeispiel einer Startvorrichtung in einer geschnittenen Ansicht mit den Merkmalen der vorliegenden Erfindung,
• Figur 2 eine Ansicht einer Seilscheibe mit einem Gegenanschlag,
• Figur 3 eine Seitenansicht eines Mitnehmergliedes, in dem ein Anschlagelement eingebracht ist,
• Figur 4 eine perspektivische Ansicht der Startvorrichtung gemäß eines weiteren Ausführungsbeispiels,
• Figur 5 eine weitere Ansicht einer Startvorrichtung gemäß dem Ausführungsbeispiel in Figur 4,
• Figur 6 eine quergeschnittene Seitenansicht eines Ausführungsbeispiels der Startvorrichtung gemäß dem Ausführungsbeispiel aus Figur 4 und Figur 5,
• Figur 7a eine perspektivische Ansicht einer Dämpfungsfeder gemäß einem ersten Ausführungsbeispiel,
• Figur 7b eine perspektivische Ansicht einer Dämpfungsfeder gemäß einem zweiten Ausführungsbeispiel und
• Figur 7c eine perspektivische Ansicht einer Dämpfungsfeder gemäß einem dritten Ausführungsbeispiel.

Further, measures improving the invention will be described in more detail below together with the description of preferred embodiments of the invention with reference to FIGS. It shows:

• FIG. 1 An embodiment of a starting device in a sectional view with the features of the present invention,
• FIG. 2 a view of a pulley with a counter-stop,
• FIG. 3 a side view of a driver element, in which a stop element is introduced,
• FIG. 4 a perspective view of the starting device according to another embodiment,
• FIG. 5 a further view of a starting device according to the embodiment in FIG. 4 .
• FIG. 6 a cross-sectional side view of an embodiment of the starting device according to the embodiment of FIG. 4 and FIG. 5 .
• Figure 7a a perspective view of a damping spring according to a first embodiment,
• FIG. 7b a perspective view of a damping spring according to a second embodiment and
• FIG. 7c a perspective view of a damping spring according to a third embodiment.

PREFERRED EMBODIMENTS OF THE INVENTION

In FIG. 1 an embodiment of a starting device 100 for an internal combustion engine with a rotatably mounted in a housing 10 sheave 11 is shown. On the pulley 11, a traction means 13 is wound, which is designed in the form of a rope. The pulley is rotatably mounted in the housing 10, and if 13 is pulled manually at one end of the traction means, the pulley 11 can be set in rotary motion. The pulley 11 is rotatably mounted about a central axis 22, wherein a damping spring 14 is shown, which is connected in a manner not shown with a cable pulley 11 towards the end with this fixed. On the opposite side of the pulley 11 of the damping spring 14 is a driver member 15, and the end of the damping spring 14, which faces in the direction of the driver member 15 is rotationally connected to the driver member 15. Consequently, the damping spring 14 forms a torsion element which connects the pulley 11 with the driver member 15 torsionally elastic. As a result of the torsional elasticity of the damping spring 14, a relative rotation between the cable pulley 11 and the driver member 15 can take place.

If the pulley 11 is caused to rotate by pulling on the traction means 13, then the damping spring 14 likewise rotates about the central axis 22. In this case, the driver member 15 is also set in rotary motion, which can engage via a Mitnehmerkontur 15a not shown in detail pawl elements, by which the motor shaft of the engine can be turned on. About a central screw 23, the pulley 11, the damping spring 14 and the driver member 15 are rotatably received on a bearing mandrel 25 which is formed as part of the housing 10. A return spring 24 serves to turn back the pulley 11 counter to the direction of rotation when the traction means 13 is given back again. When pulling the traction means 13, the pulley 11 is turned in the direction of rotation of the motor shaft, while the traction means 13 is unwound from the pulley 11. To follow To drive the pulley 11 again rotating in the opposite direction, the return spring 24 is used, so that the traction means 13 can be wound up again.

In the driver member 15, a stopper member 16 is used, which is exemplified as a pin member and is disposed in a bore which is incorporated in the driver member 15. The bolt-like stop member 16 is made of a steel material and protrudes a little way out of the surface of the driver member 15, which faces in the direction of the pulley 11. Corresponding to the arrangement of the stop element 16, a guide groove 18 is inserted in the sheave 11, and when a relative rotation of the driver 15 takes place with simultaneous torsion of the damping spring 14 relative to the sheave 11, the stop element 16 runs in the guide groove 18 until the stop element 16 against a not shown detent stop comes to the plant.

FIG. 2 shows a view of the pulley 11 from the direction in which the pulley 11 to the driver member 15 has. In the shown surface of the pulley 11, the guide groove 18 is shown, and a counter-stop 17 is introduced in the course of the guide groove 18. The counter-stop 17 is shown by way of example as a metallic insert element, and the sheave 11 is made of a plastic material, so that the counter-stop 17 according to the invention has a material of higher strength than the sheave 11.

FIG. 3 shows a side view of the driver member 15 in which a stop element 16 is inserted, which is designed as a bolt element and consists of a steel material. The driver member 15, however, is made of a plastic material, so that the stop member 16 according to the invention has a higher strength material than the driver member 15th

In FIG. 4 a further embodiment of a starting device 100 is shown with a housing 10 in which a pulley 11 is rotatably received. Also shown is a damping spring 14, wherein for the perspective view of the pulley 11 and the arrangement of the damping spring 14, the driver member 15 is removed, the central screw 23 is shown, which indicates the axis of rotation of the pulley 11 and the damping spring 14. Furthermore, an ejector handle 12 is shown, the end of the traction means 13th is arranged. If a tensile force is manually introduced via the starter handle 12 into the traction means 13, the pulley 11 is brought into rotation about the central screw 23.

The damping spring 14 has a first end 14a, via which the damping spring 14 is connected to the driver member 15, not shown in detail. Furthermore, the damping spring 14 has a second end 14 b, which is arranged rigidly in the pulley 11.

For the rigid arrangement of the second end 14b of the damping spring 14 in the pulley 11, this has a receptacle 20, and the second end 14b of the damping spring 14 is inserted with a first portion in the receptacle 20. A second section 21 of the second end 14b of the damping spring 14 protrudes from the receptacle 20 and forms the counter-stop 17, against which a stop element 16 of the driver 15 is brought to bear when the angle of rotation of the pulley 11 relative to the driver member 15 reaches a maximum value. The second portion 21 of the second end 14b of the damping spring 14 projecting out of the receptacle 20, and the damping spring 14 is made of a metallic material of high strength, and the material of the damping spring 14 is harder than the material of the sheave 11, preferably made of Plastic is made.

In FIG. 5 the driver member 15 is shown in a sectional view and this has a first stop surface for forming the stop member 16, and the second portion 21 of the second end 14b of the damping spring 14, which protrudes from the receptacle 20 of the sheave 11, is located on the first stop surface the stop element 16 at. If a tensile force is introduced into the traction means 13 via the starter handle 12 and the pulley 11 is rotated clockwise about the central axis 22, then the pulley 11 can twist against the driver member 15 so far that the counter-abutment 17 formed by the second Subsection 21 of the second end 14b of the damping spring 14, against the second stop surface of the stop element 16 comes into abutment. In this case, the pulley 11 is rotated by 270 ° against the driver member 15th

FIG. 6 shows a cross-sectional side view of the starting device 100 according to the embodiment of the FIGS. 4 and 5 , The housing 10 is shown in a sectional view, and the pulley 11 with the traction means 13, the damping spring 14 and the driver member 15 are rotatably mounted about the center axis 22 via the central screw 23 on a bearing pin 25 of the housing 10. In the cross-sectional view of the damping spring 14, the first end 14a and the second end 14b of the damping spring 14 can be seen. The first end 14 a is fixedly connected to the driver member 15, wherein the second end 14 b has an S-shape, and a second portion 21 protrudes from the sheave 11 to form the counter-stop 17. Against the counter-stop 17, a stop member of the driver member 15 come to rest when the driver member 15 relative to the sheave 11 reaches the maximum angle of rotation.

The Figures 7a, 7b and 7c show respective embodiments of the damping spring 14, which extend around the central axis 22. The damping springs 14 are designed as coil springs and have a conical shape. The end of the conical shape of the damper spring 14 with the smaller diameter forms the first end 14 a, which is connected to the driver member 15. The second end 14b is formed at the larger diameter of the conical shape and extends in a plane away from the body of the damper spring 14, and the plane is defined by the central axis 22 and the extension direction 26 of the second end 14b of the damper spring 14.

Figure 7a shows a damping spring 14 with a second end 14b, which is designed in the form of an inverted "U". The extension direction 26 is shown at a height that separates the first section 19 of the curved shape of the second end 14b from the second section 21. The first section 19 is for use in the receptacle 20 in the sheave 11, and the second section 21 protrudes from the receptacle 20 of the sheave 11 to form the counter-stop 17.

FIG. 7b shows an S-shape of the second end 14b, wherein the extension direction 26 is shown at half the S-height. Consequently, the lower, first portion 19 of the S-shape can be inserted into the receptacle 20, and the upper, second portion 21 protrudes from the receptacle 20.

FIG. 7c shows a C-shape of the second end 14b of the damping spring 14, and the lower first portion 19 is in turn inserted into the receptacle 20, while the upper second portion 21 protrudes from the receptacle 20 to form the counter-stop 17.

The invention is not limited in its execution to the above-mentioned preferred embodiment. Rather, a number of variants is conceivable, which makes use of the illustrated solution even with fundamentally different types of use. Any features and / or advantages resulting from the claims, the description or the drawings, including constructive details or spatial arrangements, can be essential to the invention, both individually and in the most diverse combinations.

LIST OF REFERENCE NUMBERS

100

starter

10

casing

11

sheave

12

Anwerfergriff

13

traction means

14

damping spring

14a

first end

14b

second end

15

driver link

15a

driver contour

16

stop element

17

counterstop

18

guide

19

first part of the curved shape

20

admission

21

second part of the curved shape

22

central axis

23

central screw

24

return spring

25

bearing mandrel

26

extension direction

Claims (10)

Starting device (100) for an internal combustion engine with a in a housing (10) rotatably mounted pulley (11) for generating a driving torque for a motor shaft by means of a Anwerfergriffs (12) via a traction means (13) in rotation displaceable over one of a Spring wire formed damping spring (14) with a driver member (15) is connected, by means of which the drive torque to the motor shaft for starting the internal combustion engine is transferable, wherein under torsion of the damping spring (14) a rotation of the pulley (11) against the driver member (15) is possible, until the limitation of rotation, a stop element (16) against a counter-stop (17) passes, characterized in that the stop element (16) and / or the counter-stop (17) is formed of a material having a higher strength than the material of the driver member (15) and / or as the material of the sheave (11). Starting device according to claim 1, characterized in that the stop element (16) made of a metallic material, in particular of a steel material, is formed, wherein in particular the driver member (15) and / or the sheave (11) is formed of a plastic material. Starting device according to claim 1 or 2, characterized in that the stop element (16) on the driver member (15) is arranged and from a pulley (11) facing surface of the driver member (15) protrudes, in particular that the stop element (16) as a pin member or is formed as a bolt element and extends from the pulley (11) facing surface of the driver member (15) in the direction of the sheave (11) out. Starting device according to one of claims 1 to 3, characterized in that in the pulley (11) has a guide groove (18) is introduced, in which the stop element (16) is guided, wherein the counter-stop (17) engages in the guide groove (18) , Starting device according to one of the preceding claims, characterized in that the counter-stop (17) as an insert element made of a material of high strength, in particular as an insert element of a metallic material, formed and inserted in the sheave (11). Starting device according to one of the preceding claims, characterized in that the spring wire of the damping spring (14) has two ends (14a, 14b) and a first end (14a) with the driver member (15) and a second end (14b) with the sheave ( 11) is engaged, and wherein the counter-stop (17) from the spring wire of the damping spring (14) is formed, which in particular has a metallic material of high hardness. Starting device according to one of the preceding claims, characterized in that the counter-stop (17) from the second end (14b) of the spring wire of the damping spring (14) is formed, which is in engagement with the sheave (11). Starting device according to one of the preceding claims, characterized in that the second end (14b) of the spring wire of the damping spring (14) has a curved shape, wherein the curved shape with a first portion (19) in a receptacle (20) of the pulley (11 ) is enclosed for engagement in this and with a second portion (21) from the receptacle (20) of the pulley (11) protrudes in the direction of the driver member (15). Starting device according to one of the preceding claims, characterized in that the curved shape of the second end (14b) of the spring wire of the damping spring (14) has an S-shape, a C-shape or an inverted U-shape. Starting device according to one of the preceding claims, characterized in that the second end (14b) of the spring wire of the Damper spring (14) extends with its curved shape in a plane, in particular that the S-shape, the C-shape or the inverted U-shape extends in a plane, wherein the damping spring (14) has a central axis (22) is in the plane of the second end (14b).

Images