Starter for an internal combustion engine

Patent metadata

Field	Value
Publication number	US-10337484-B2
Application number	US-201615761083-A
Country	US
Kind code	B2
Filing date	Sep 14, 2016
Priority date	Sep 18, 2015
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

A starter for an internal combustion engine may include a support, an electric motor for driving a pinion in rotation, and a solenoid drive configured to axially adjust the pinion between an active position for driving a gearwheel of an internal combustion engine, and an axially offset passive position. The solenoid drive may include a ferromagnetic solenoid housing fastened to the support, a ferromagnetic plunger stop arranged one of in and at the solenoid housing, a ferromagnetic plunger axially adjustable relative to the plunger stop extending axially through a passage opening of a face side wall of the solenoid housing, and a cylindrical coil arrangement arranged in the solenoid housing surrounding a cylindrical coil interior in a circumferential direction. The plunger stop may include a cylindrical section projecting axially into the coil interior. The cylindrical section may have a face end facing towards the face side wall.

First claim

The invention claimed is:

1. A starter for an internal combustion engine, comprising:
a support;
an electric motor arranged on the support for driving a pinion in rotation;
a solenoid drive arranged on the support configured to axially adjust the pinion between an active position for driving a gearwheel of an internal combustion engine, and a passive position axially offset with respect to the active position;
wherein the solenoid drive has a ferromagnetic solenoid housing coupled to the support, a ferromagnetic plunger stop arranged one of in and at the solenoid housing, a ferromagnetic plunger axially adjustable relative to the plunger stop and extending axially through a passage opening of a face side wall of the solenoid housing, and a cylindrical coil arrangement arranged in the solenoid housing and surrounding a cylindrical coil interior of the coil arrangement in a circumferential direction;
wherein the plunger stop has a cylindrical section projecting axially into the coil interior; and
wherein the cylindrical section has a face end facing towards the face side wall and includes a cylindrical chamber, the plunger protruding axially into the cylindrical chamber when the pinion is in each of the active position and the passive position.

2. The starter according to claim 1 , wherein:
the coil interior includes a proximal half section and a distal half section, the proximal half section disposed closer to the face side wall than the distal half section; and
the face end of the cylindrical section is arranged in the proximal half section of the coil interior.

3. The starter according to claim 1 , wherein the cylindrical section extends over more than 50% of an axial length of the coil arrangement.

4. The starter according to claim 3 , wherein the cylindrical section extends over at least 75% of the axial length of the coil arrangement.

5. The starter according to claim 1 , wherein:
at least when the pinion is in the passive position, an axial gap is defined between the face end of the cylindrical section and a portion of the plunger;
an axial distance of the gap is reduced when the pinion is adjusted from the passive position to the active position and the portion of the plunger is adjusted towards the face end of the cylindrical section; and
the gap is arranged proximal to the face side wall.

6. The starter according to claim 5 , wherein the face side wall has an inner side facing towards the coil arrangement and, when the pinion is in the passive position, the gap axially overlaps at least substantially completely a radially inner edge of the inner side.

7. The starter according to claim 5 , wherein:
the plunger includes a protrusion section protruding axially into the cylindrical chamber, and a head section arranged in axially adjustable fashion in an edge region bordering the passage opening in a circumferential direction, the head section having a larger cross-sectional area than a cross-sectional area of the protrusion section; and
the portion of the plunger is an annular step arranged between the protrusion section and the head section.

8. The starter according to claim 1 , wherein the plunger is coupled via a diverting lever to a drive shaft connected rotationally conjointly to the pinion for axially adjusting the drive shaft, such that, during an adjustment of the pinion from the passive position into the active position, the plunger extends to an increasing depth into the cylindrical chamber.

9. The starter according to claim 7 , wherein, when the pinion is in the passive position, the annular step is arranged axially outside of the coil interior.

10. The starter according to claim 7 , wherein, when the pinion is in the active position, the annular step bears axially against the face end.

11. The starter according to claim 7 , wherein an axial face side of the plunger arranged in the cylindrical chamber bears axially against a base of the plunger stop, and the base of the plunger stop axially delimits the cylinder chamber when the pinion is adjusted into the active position.

12. The starter according to claim 7 , wherein the cylindrical section includes a cylindrical wall bordering the cylindrical chamber.

13. The starter according to claim 12 , wherein one of:
the cylindrical wall includes at least one recess delimited in a circumferential direction and extending at least one of radially and axially at least over a part of the cylindrical wall; and
the cylindrical wall surrounds the cylindrical chamber in a closed encircling fashion in a circumferential direction and with a constant wall thickness.

14. The starter according to claim 1 , wherein the plunger is, at least in an axial section protruding into the cylindrical chamber, cylindrically hollow such that a cylindrical plunger wall surrounds a cavity.

15. The starter according to claim 14 , wherein the plunger wall surrounds the cavity in a closed encircling fashion in a circumferential direction and with a constant wall thickness.

16. The starter according to claim 14 , wherein the plunger wall includes at least one recess delimited in a circumferential direction and extending at least one of radially and axially at least over a part of the plunger wall.

17. The starter according to claim 7 , wherein:
the plunger is arranged in an axially adjustable fashion in a guide sleeve extending coaxially through the coil interior and supported radially on the cylindrical section;
the coil arrangement is supported radially at an inside on the guide sleeve; and
the edge region is supported radially at an inside on the guide sleeve.

18. A starter for an internal combustion engine, comprising:
a support;
an electric motor arranged on the support for driving a pinion in rotation;
a solenoid drive arranged on the support configured to axially adjust the pinion between an active position for driving a gearwheel of an internal combustion engine, and a passive position axially offset with respect to the active position, the solenoid drive including:
a ferromagnetic solenoid housing coupled to the support;
a ferromagnetic plunger stop arranged one of in and at the solenoid housing;
a ferromagnetic plunger axially adjustable relative to the plunger stop and extending axially through a passage opening of a face side wall of the solenoid housing; and
a cylindrical coil arrangement arranged in the solenoid housing and surrounding a cylindrical coil interior of the coil arrangement in a circumferential direction;

wherein the plunger stop has a cylindrical section projecting axially into the coil interior, the cylindrical section having a face end facing towards the face side wall;
wherein, at least when the pinion is in the passive position, an annular gap extending axially between the face end of the cylindrical section and a portion of the plunger is defined, the gap at least partially disposed radially between the plunger and the face side wall; and
wherein an axial distance of the gap is reduced when the pinion is adjusted from the passive position to the active position and the portion of the plunger is adjusted towards the face end of the cylindrical section.

19. A starter for an internal combustion engine, comprising:
a support;
an electric motor arranged on the support for driving a pinion in rotation;
a solenoid drive arranged on the support configured to axially adjust the pinion between an active position for driving a gearwheel of an internal combustion engine, and a passive position axially offset with respect to the active position, the sol

Assignees

• Mahle Int Gmbh

Inventors

• Florijancic Tadej
• Kobal Sebastjan

Classifications

• F02N15/067 Primary

  the starter comprising an electro-magnetically actuated lever · CPC title

• F02N11/087

  Details of the switching means in starting circuits, e.g. relays or electronic switches · CPC title

• H01F7/081

  Magnetic constructions · CPC title

• H01F7/16

  Rectilinearly-movable armatures (H01F7/17 takes precedence) · CPC title

• F02N2015/061

  said axial displacement being limited, e.g. by using a stopper · CPC title