CN108474342B - Starter device for internal combustion engine - Google Patents

Abstract

Starting device (10) for an internal combustion engine, with: a toe-in actuator (16) having an axially movable armature (17); an axially movable starter pinion (22); a lever assembly (125) coupled at one location (137) with the armature (17) and at least indirectly coupled at least one other location with the starter pinion (22); a bearing portion (140) on which the lever assembly (125) is rotatably supported; a pre-tensioned spring element (131) that is part of the lever assembly (125) and to which the armature (17) is coupled; a lever portion (128) which engages at one end on the driven shaft (108), characterized in that a region (148) of the pretensioned spring element (131) is arranged between the lever portion (128) and the cover (151).

Description

Starting device for internal combustion engine

Background

DE 102011003200 a1 discloses a starting device for an internal combustion engine, the lever assembly of which has a lever part which engages with one end on a driven shaft and has a pretensioned spring element which is coupled to an armature of a toe-in actuator.

It has been found that when the pretensioned spring element is actuated, it rubs against the bearing block and in this case performs a supporting function, thus reducing the force available on the output shaft for the axial thrust of the starter pinion.

Disclosure of Invention

The starting device for an internal combustion engine according to the present invention has: a toe-in actuator having an axially movable armature; an axially movable starter pinion; a lever assembly coupled at one location to the armature and at least indirectly coupled at least one other location to the starter pinion; a bearing portion at which the lever assembly is rotatably supported on the support member; a pre-tensioned spring component that is part of the lever assembly, the armature being coupled to the pre-tensioned spring component; a lever part which engages at one end on the output shaft, wherein, in the bearing region, a region of the pretensioned spring element is arranged between the lever part and the cover. The starting device for an internal combustion engine having the above-mentioned features has the following advantages: by providing a pretensioning spring element between the lever part and the cover, the pretensioning element can no longer rub directly against the bearing block as a support element. This can be achieved, on the one hand, by producing the bearing block from a constant material and, on the other hand, by means of suitable friction parameters, by specifically adjusting the friction conditions between the prestressing element and the location at which the prestressing element rubs on the bearing block side. This can be achieved in particular in that the material is selected appropriately. The cover instead also bears against an available part different from the bearing surface, so that ultimately a lower frictional force is available via the cover, since by using the cover it is possible to adjust the frictional parameters between the pretensioning spring element and the cover more easily, since the cover is a less complex component than the bearing seat.

According to a further aspect of the invention, it is provided that the cover is arranged between the support element and the region of the pretensioned spring element. This preferably prevents the pretensioning spring element from bearing against the support element. The support part can be designed here, for example, as a so-called bearing block, so that it can form part of a bearing region on which the lever assembly is rotatably supported.

In particular, it is provided that the coefficient of sliding friction between the material of the region of the pretensioned spring element and the support element is greater than the coefficient of sliding friction between the material of the region of the pretensioned spring element and the cover. This is achieved, for example, in the following way: the material of the region of the pretensioning spring element is made of spring steel, the support element is made of a polymeric plastic, such as polyamide or an elastomer, and the cover is made of a steel material.

According to a further aspect of the invention, it is provided that the cover is preferably fastened to the shank. Alternatively, it can be provided that the cover is not fastened to the shaft part, but rather to the support part. In the latter case mentioned, the cover may actually be a coating of the support member, which is for example glued or clipped onto the support member mentioned.

According to a further aspect of the invention, it is provided that the cover preferably has at least one retaining arm, particularly preferably two retaining arms, which engage into the retaining contour, as a result of which the cover retaining position can be fixed. Such a retaining profile may be, for example, a profile on the shaft portion. It is particularly preferred that this contour or retaining contour is designed as a latching projection or retaining slot.

The stem portion as a plastic moulding is preferably made of a polymeric plastic, for example polyamide. The rod portion is coupled at one end to the driven shaft. The driven shaft is preferably a starter pinion with an engagement contour for the lever assembly, or for example a starter pinion with a freewheel with an engagement contour for the lever assembly. The lever assembly preferably has components which participate in converting the movement of the armature of the toe actuator into a shifting movement of the starter pinion.

The cover can be made not only of steel but alternatively also of aluminum, brass, bronze or a particularly low-friction polymer.

The invention is described below by way of example with the aid of the accompanying drawings.

Wherein:

FIG. 1 is a cross-sectional view of a drive arrangement of the present invention;

FIG. 2 is a longitudinal cross-sectional view of the lever assembly according to the first embodiment;

FIG. 3 is a cross-sectional view of the forked rod with the cover;

fig. 4 is an exploded view of a detail of the lever assembly consisting of the lever portion, the preloaded spring member, and the cover.

Detailed description of the preferred embodiments

A longitudinal section through astarting device 10 for an internal combustion engine can be taken from the illustration according to fig. 1. Thestarter device 10 has, for example, astarter motor 13 and a toe-inactuator 16, which is designed in the present case as a relay with alifting magnet 17.Starter motor 13 andelectric toe actuator 16 are attached to a common driveend bearing cap 19. Thestarter motor 13 is used to functionally drive thestarter pinion 22 when it meshes with aring gear 25 of the internal combustion engine, not shown in fig. 1. Thestarter motor 13 has the following general features.

The pole tube carries on its inner circumference astator pole 31 which surrounds an armature 37 (rotor). Thedrive shaft 44 of thearmature 37 carries, at its end facing thestarter pinion 22, asun wheel 80 which drives threeplanet wheels 86. Threeplanet wheels 86 are located on thebearing journal 92, which are connected in a rotationally fixed manner to afollower 94 of afreewheel 96. Theplanet wheels 86 roll on the inner circumference of thering gear 99. Therolling collar 102 of thefreewheel 96 is moved along by means of theclamping body 105. In this exemplary embodiment, the rolling collar is part of a drivenshaft 108, which is coupled to thestarter pinion 22 via a coarse-pitch threadedcoupling 111. Around thefreewheel 96 and the planetary gear train 83, a so-called intermediate bearing 114 is provided, which centrally carries abearing element 115, which is designed here as a sliding bearing. By means of this bearingpart 115, the drivenshaft 108 is supported in the intermediate bearing 114. Thesupport member 118 is integrally connected with the intermediate bearing 114. The support part preferably has the following tasks: filling the opening in the driveend bearing cap 19 facing the toe-inactuator 16. The opening 119 receives aconnection piece 122 of the relay housing. The widened opening of theopening 119, which is not visible here or is only visible indirectly, is at least partially closed off by thesupport part 118 in the direction of the pole tube 28. The end of the joint facing thetoe actuator 19 terminates in the same plane as the area at the upper end of the driveend bearing cap 19. Thesupport member 118 and the driveend bearing cap 19 here provide a flat, substantially circular opening to the housing of thetoe actuator 16 and at the same time a support surface. In the drive-end bearingcap 19 there is alever assembly 125 which has alever part 128 on the one hand and apretensioned spring part 131 on the other hand. Thelever assembly 125 is coupled here directly to thestarter pinion 22 atpoint 134 by means of thelever portion 128. A preloadedspring element 131 is rotatably coupled to thelever portion 128. The spring or preloadedspring element 131 essentially comprises twoleg legs 132, 133 (helical torsion springs), wherein thefirst leg 132 extends between the axis of rotation of the lever assembly and apoint 137, at which thelever assembly 125 is coupled to thearmature 17. Thesecond leg 133 of thepretensioned spring element 131 extends between the axis of rotation of the lever assembly and the point at which thelever part 128 engages on theoutput shaft 108, see fig. 2. Fig. 2 shows a side view of thebearing portion 140.

Between the two legs, ahelical portion 143 is present, which is formed by two oppositely woundhelical lines 144 and 145 of thepretensioned spring element 131, see fig. 3. The twohelical wires 144 and 145 thus snap into the cavity of the rod portion, so that the preloadedspring element 131 and therod portion 128 form apre-assembled rod assembly 125. Aregion 148 of thepretensioned spring element 131 is arranged between thelever part 128 and thecover 151.

Astarting device 10 for an internal combustion engine is therefore disclosed, having atoe actuator 16 with an axiallydisplaceable armature 17 and having astarter pinion 22 which is axially displaceable. Furthermore, thestarting device 10 has alever assembly 125, which is coupled to thearmature 17 at apoint 137. At least oneother point 134, the lever assembly is coupled at least indirectly to thestarter pinion 22. The starting device also has abearing portion 140 on which thelever assembly 125 is rotatably supported.Pre-tensioned spring element 131 is part oflever assembly 125. The following preloaded spring components are also present: which is part of arod assembly 125 and to whicharmature 17 is coupled. Therod portion 128 is engaged at one end on the drivenshaft 108. Aregion 148 of thepretensioned spring element 131 is arranged between thelever part 128 and thecover 151. Furthermore, thecover 151 is arranged between thesupport part 118 and theregion 148 of thepretensioned spring part 131. Thesupport part 118 can also be designed here as a bearing block, which indirectly or directly rotatably supports thelever assembly 125.

In terms of the material properties of the relevant components, it is provided that the coefficient of sliding friction between the material of theregion 148 of thepretensioned spring element 131 and thesupport element 118 of thepretensioned spring element 131 is greater than the coefficient of sliding friction between the material of theregion 148 of thepretensioned spring element 131 and thecover 151.

In fig. 3 a cross-sectional view is shown, taken along the line III-III as shown in fig. 2. The twohooks 160, 161 are clearly visible, with the two retainingarms 168 and 170 overlapping the hooks. In addition, the cross section of thecover 151 can be seen. Retainingarms 168 and 170 extend from thecover 151 at one end 163 and at the other end 166, respectively. The retainingarms 168 and 170 each have aneye 173 and 176 that move past the twohooks 160, 161. To facilitate insertion or movement past thehooks 160, 161, the two retainingarms 173 and 176 are provided with beveled ends 178 and 180. The two retainingarms 168 and 170 receive the twohelical portions 144 and 145 therebetween. Thus, theregion 148 is received between the two retainingarms 168 and 170. Thecover 151 is thereby fixed to thelever portion 128. Furthermore, thecover 151 engages with at least one retainingarm 168, 170 into a retainingcontour 183, represented by twohooks 160, 161, on therod portion 128.

An exploded view showing thelever portion 128, thepretensioned spring element 131 and thecover 151 is shown in fig. 4. As can be clearly seen here, thecover 151 is designed in one piece with the retainingarms 168, 170. Thecover portion 151 with theretention arms 168 and 170 is made of sheet material. Thecover 151 here essentially has the shape of a half of a substantially annular or circular tube from which abeveled portion 186 or 187 at its end projects. These inclined portions serve to envelop thespiral wires 144, 145 so that there is no angular scraping on these spiral wires.

The cover may be secured to therod portion 128 orrod assembly 125 or alternatively may be secured with additional components such as screws or bolts. Furthermore, thecover 151 can also be fixed in therod portion 128 by means of a slotted profile, into which the right-angled sections connected to the cover portion or cover 151 are inserted.

Other alternatives for securing or pressing thecover 151 onto therod portion 128 are to adhesively secure or injection mold the cover.

Claims (7)

1. Starting device (10) for an internal combustion engine, with:

-a toe-in actuator (16) having an axially movable armature (17);

-an axially movable starter pinion (22);

-a rod assembly (125) coupled in one portion (137) with said armature (17) and in at least one other portion at least indirectly with said starter pinion (22);

-a bearing location (140) at which the lever assembly (125) is rotatably supported on the support member (118);

-a pre-tensioned spring element (131) being part of the rod assembly (125), the armature (17) being coupled to the pre-tensioned spring element;

a rod portion (128) engaged at one end on the driven shaft (108),

characterized in that, in the bearing region (140), a region (148) of the pretensioned spring element (131) is arranged between the lever part (128) and a cover (151), the cover (151) being arranged between the support element (118) and the region (148) of the pretensioned spring element (131).

2. A starting device according to claim 1, characterized in that the coefficient of sliding friction between the material of the region (148) of the pretensioned spring element (131) and the support element (118) is greater than the coefficient of sliding friction between the material of the region (148) of the pretensioned spring element (131) and the cover (151).

3. The starting device according to any of the preceding claims, characterized in that the cover (151) is fixed to the lever portion (128).

4. A starting device according to claim 3, characterized in that the cover (151) has at least one retaining arm (168, 170) which engages into a retaining profile (183).

5. A starting device according to claim 4, characterized in that the retaining profile (183) is a hook (160, 161) or a retaining slot.

6. A starting device according to any one of claims 1 or 2, characterized in that the cover (151) is fixed to the support member.

7. A starting device according to claim 6, characterised in that the cover (151) is glued or clipped onto the support part.

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