FR3039860A1 - INTERNAL COMBUSTION ENGINE STARTER DEVICE - Google Patents

Abstract

Internal combustion engine starter device having a starter gear (2) axially movable on a drive shaft between an out of position position and a position engaged with the ring gear (3) of the internal combustion engine (4) driven by a motor (11), and a shaft-stop ring connection in the transition path between the drive motor shaft (11) and a shaft (14) carrying the starter gear (2). The abutment ring (13) forms a closed ring and is made of a shape memory material; the abutment ring (13) in its axial reference position on the shaft (14) corresponds to the stable phase of its material.

Description

Field of the invention

The present invention relates to an internal combustion engine starter device comprising a starter pinion axially movable on a drive shaft between, on the one hand, an out of position position and a position in engagement with the ring gear of the combustion engine. internal combustion being driven by a motor, and secondly a shaft-stop ring connection in the transmission path between the drive motor shaft and a shaft carrying the starter gear.

State of the art

The internal combustion engine starter devices, for example according to DE 10 2010 041 797 A1, are equipped with a starter pinion axially movably mounted on a drive shaft. These gears are moved by the starter relay between an off-setting position, recessed and an advanced axial position, engaged with the ring gear of the internal combustion engine. In the setting position, the starter gear is driven by the electric motor of the starter whose drive movement is multiplied by an epicyclic transmission. The axial advance movement produced by the starter relay is transmitted to the drive member of a freewheeling clutch which is integrally connected to the starter pinion gear shaft. The drive member is carried by the drive shaft to which it is coupled by a thread with a fast pitch. The axial advance movement moves the drive member along the fast pitch thread so that the drive member and the starter gear execute a rotational movement which facilitates meshing in the ring gear. The axial advance movement of the starter gear is limited by an abutment ring axially integral with the drive shaft.

Description and advantages of the invention

The present invention relates to a starter device of the type defined above, characterized in that the stop ring forms a closed ring and is made of a shape memory material, the stop ring in its set position. , axial on the shaft corresponding to the stable phase of its material.

In other words, the subject of the invention is a starter device for an internal combustion engine having a starter gear movable on a drive shaft, in axial movement between a non-engaged position and a position engaged with the ring gear of the internal combustion engine. This pinion is driven by an electric motor. The starter device further comprises a shaft-stop ring connection in the transmission path between the shaft of the electric motor and the shaft carrying the starter gear. The stop ring is a closed ring made of a shape memory material. In its axial setpoint position on the shaft, the material of the thrust ring is in its stable phase.

The starter device according to the invention has the advantage that the closed ring is fixed stably on the shaft, even at high rotational speeds and opposite the open abutment rings, there is no risk radial expansion under the effect of centrifugal forces so that despite the high speeds of rotation, the connection between the thrust ring and the shaft remains assured. This solution avoids any means of protection against enlargement and which is necessary in the case of the open rings or prevent them from widening in the radial direction; such a protection against enlargement device radially surrounds the abutment ring in the known solutions. In contrast to this, the starter device according to the invention reduces the number of components necessary for the realization of the link shaft-stop ring.

The fixed axial position of the thrust ring on the shaft results from the properties of the closed abutment ring resting on its embodiment as a shape memory part which, in its set position, is axially retracted radially by exerting a radial force of significant tightening on the shaft. The stop ring made of a shape memory material has at least one stable phase and, where appropriate, two stable phases of the material. In its axial setpoint position on the shaft, the thrust ring is in its stable phase. This has the effect of permanently maintaining the stop ring in its stable phase setpoint position and thus the clamping force exerted by the stop ring on the shaft remains permanent. In any stable phase, the thrust ring has a defined geometric position.

In addition, the transition to stable phase is carried out at the mounting either automatically or with simple means.

When one arrives in the stable phase of the material, a large radial clamping force stably maintains the stop ring in its desired axial position on the shaft. In the stable phase of the material that the stop ring takes for its axial setpoint position on the shaft, the thrust ring has a reduced internal diameter compared to that of the non-stable phase so as to guarantee the radial force of tightening, important, wanted on the tree.

The stop ring can be enlarged before mounting and slid in this state on the shaft to the target axial position; then, the stop ring is passed in its stable phase with reduced diameter. This embodiment is particularly suitable for abutment rings of a shape memory material having two stable phases, the abutment ring being in a radially expanded state in a first stable phase to allow its fitting. This stable phase is maintained to the target axial position and at this point the thrust ring is passed into its second stable phase with reduced diameter. The passage is for example by heating the stop ring, for example with the hot air.

According to an advantageous variant, the stop ring slips on the shaft in the unexpanded state and is widened radially during this installation. Thus, a pseudoelasticity effect of the shape memory material is used; according to this effect, the abutment ring, by comparison with any other material, can be expanded elastically very strongly. When one reaches the target axial position in which the shaft segment concerned, preferably a reduced outer diameter, the stop ring takes its stable phase corresponding to the reduced diameter. The transition to stable phase is preferably done automatically without external intervention.

According to an advantageous development, the shaft segment which corresponds to the axial reference position of the thrust ring has a reduced outer diameter relative to the segment next to the shaft. The shaft segment concerned is for example made in the form of a peripheral groove for receiving the thrust ring. It is also possible to limit the shaft segment for the target axial position only on one side by a peripheral wall which corresponds, for example to the front surface of a conical widening of the shaft that the stop ring must pass for its fitting on the tree.

Since the shaft segment corresponding to the target axial position has no reduced diameter, the connection between the thrust ring and the shaft will be made only with large clamping forces exerted by the thrust ring. on the tree because of the stable phase of its material. To increase the friction, it is possible, if necessary, to roughen the surface of the shaft in the region of the shaft segment corresponding to the desired axial position.

According to an advantageous development, the shaft has a groove for receiving the thrust ring. On assembly, the groove is reached either with a pre-expanded abutment ring or by widening during the fitting on the shaft and then the thrust ring automatically takes its reduced diameter or under an external effect to go into a stable phase. . The groove has the advantage of holding the thrust ring axially in both directions by a connection by the shape on the shaft. In addition, the thrust ring exerts a radial clamping force on the shaft.

As shape memory material, it is possible to envisage various materials such as a shape memory alloy, especially a nickel titanium alloy (NiTi). It is also possible to envisage other materials or alloys with shape memory, for example copper-zinc, copper-zinc-aluminum, copper-zinc-nickel or iron-nickel-aluminum.

As a shape memory material, it is also possible to produce the stop ring in a bimetal which also has one or preferably two stable phases of the material.

According to another advantageous development, the thrust ring makes it possible axially to limit the movement of the starter gear of the starter device. According to a first advantageous embodiment, the thrust ring is installed on the pinion shaft and limits the axial movement of the starter pinion biased by a spring on the shaft. The pinion shaft with the spring-loaded starter pinion sliding axially on the shaft moves between an engaged position and a non-engaged position. The relative axial movement of the starter gear on the shaft dampens the shock for a tooth-to-tooth position between the starter gear and the ring gear of the internal combustion engine. The starter pinion is pushed against the thrust ring of the pinion shaft axially by the spring element acting on the pinion and in the case of a tooth against tooth position with the ring gear, it can escape axially. against the force developed by the spring element.

According to another advantageous development, the shaft which receives the thrust ring is the shaft driven in rotation by the motor. The starter gear, if any, with the pinion shaft is axially movable on the drive shaft between an off-position and a position engaged with the ring gear of the internal combustion engine; this axial forward movement is limited by the thrust ring of the shaft.

According to another advantageous development, the end face of the starter pinion comprises an axial groove or groove through which the starter pinion rides the stop ring in the setting position. This allows for a compact starter device in the axial direction because the starter gear is certainly limited in its axial movement by the stop ring, but because of the overlap, the stop ring does not require additional space.

Advantageously, in abutment phase, the end face of the starter pinion is level with the front face of the shaft so that, on the one hand, there is sufficient axial travel for the starter pinion on the starter pinion. shaft, to compensate in the case of a tooth against tooth position and secondly, there is no extra space that would be required to the thrust ring on the pinion shaft.

According to another advantageous development, the shaft of the abutment-shaft link is the shaft of the drive electric motor. The thrust ring fixes the shaft axially in the motor housing. This fixing is done in particular in the region of the bearing of the shaft in the housing so that this bearing exerts the function of a fixed bearing. The axial attachment of the motor shaft may further or alternatively limit the axial movement of the starter gear on the shaft (the pinion shaft and / or the drive shaft).

drawings

The present invention will be described below, in more detail, using an embodiment of the starter device shown in the accompanying drawings in which like elements bear the same references.

Thus: FIG. 1 is the diagram of an internal combustion engine equipped with a starter pinion axially movable by the starter relay and driven in rotation by an electric motor; FIG. 2 is a front view of the starter gear; stop in a shape memory material, installed on the starter gear pinion shaft, FIG. 3 is an axial sectional view of the thrust ring,

Figure 4 is an axial section of the pinion shaft carrying the starter gear whose relative axial movement relative to the pinion shaft is limited by the stop ring made of a shape memory material.

Description of embodiments

According to Figure 1, the starter device 1 of an internal combustion engine comprises a starter gear 2 engaged with the ring gear 3 of the internal combustion engine to start the internal combustion engine 4. The starter gear 2 is slidably mounted axially on the drive shaft 5 as indicated by the double arrow; the starter gear 2 is for example connected to the drive shaft 5 by a fast pitch thread. The starter gear 2 is moved between an out of service, recessed position and an advanced position engaged with the ring gear 3 of the internal combustion engine 4 by the starter relay 6. This relay is an electromagnetic relay having a winding 7 powered. and a sliding armature 8. When the winding 7 is energized, the armature is retracted axially in the winding. The sliding armature 8 is coupled film-tically to the starter gear 2 by a meshing lever 9, so that the axial movement of displacement of the sliding armature 8 between its rest position and its actuated position corresponds to a movement axial adjustment of the starter gear 2 between the off position and the engaged position (gear position).

The rotational drive movement of the drive shaft 5 or the starter gear 2 is provided by an electric motor 11 coupled by an epicyclic transmission 12 to the drive shaft 5. When the electric motor 11 is activated , the drive shaft 5 and with it the starter gear 2 are rotated. The epicyclic transmission 12 and the drive shaft 5 may be connected by a freewheel arrangement to decouple the starter gear from the electric motor once the internal combustion engine has started.

The starter device 1 is completed by a regulation or control device 10 which controls the operation of the starter relay 6 and that of the electric motor 11.

In the case of an axial actuation movement of the sliding armature 8 when the starter relay 6 is activated, arriving in the set position, the dynamic coupling of the switching member on the actuating movement of the sliding armature 8 establishes the power supply of the starter motor 11 which starts to move and rotates the shaft 5 and the starter pinion 2.

Figures 2 and 3 show an abutment ring 13 installed on the pinion shaft 14 as shown in Figure 4; this stop ring limits the relative axial movement of the starter gear 2 on the pinion shaft 14. The pinion shaft 14 is carried by the drive shaft 5 (FIG. 1) while being connected thereto by a fast pitch thread. During the forward movement of the pinion shaft 14 produced by the starter relay 6, the pinion shaft 14 performs a relative rotational movement with respect to the drive shaft due to its coupling by the threading fast which facilitates meshing in the ring gear of the internal combustion engine.

The starter gear 2 is axially movable, relative to the pinion shaft by a flange; a spring element 15 pushes the starter pinion between the stop ring 13 on the side of the flange of the shaft 14 in the vicinity of its end face. The pinion shaft 14 has a groove in the vicinity of the end face to receive the thrust ring 13.

During the forward movement of the pinion shaft 14 with the starter pinion 2 towards the ring gear of the internal combustion engine, the starter pinion 2 can escape to the rear in case it happens that 'between the ring gear in a tooth against tooth position, this movement being against the force developed by the spring member 15 and from its bearing position against the stop ring 13. After meshing, the pinion of starter 2 is again pushed axially by the spring element 15 against the abutment ring 13.

The abutment ring 13 is made of a shape memory material, for example, a nickel-titanium alloy (NiTi) having at least one stable phase of material and preferably two stable phases corresponding to different inside diameters of the ring. In order to mount the abutment ring 13 on the pinion shaft 14, the abutment ring 13 is first radially expanded and in this expanded state, which preferably corresponds to a stable phase of the material, the thrust ring on the pinion shaft 14 to the nominal axial position at the groove. In the expanded state, the inner diameter of the stop ring 13 is advantageously greater than the outer diameter of the pinion shaft 14, which allows the stop ring 13 to be freely fitted onto the pinion shaft 14. .

Once in the set axial position, the stop ring is passed into its second stable phase in which the stop ring has a reduced inside diameter. This retraction operation during the passage in the second stable phase of the material is done for example by heating the abutment ring 13 with hot air in the second stable phase of the material, the diameter of the abutment ring 13 is reduced and in particular it is small enough to exert a radial clamping force on the bottom of the groove which receives the abutment ring on the pinion shaft 14. In addition, the connection by the shape is limited in both directions by the walls of the throat.

NOMENCLATURE OF THE MAIN ELEMENTS 1 Starter device 2 Starter gear 3 Gear ring of the internal combustion engine 4 Internal combustion engine 5 Drive shaft 6 Starter relay 7 Relay winding 8 Sliding arm 9 Gear lever 10 Control unit and control 11 Electric drive motor 12 Planetary gear 13 Thrust ring 14 Pinion shaft 15 Spring element

Claims (10)

1 °) Internal combustion engine starter device comprising a starter gear (2) axially movable on a drive shaft between an out of position position and a position in engagement with the ring gear (3) of the combustion engine internal (4) being driven by a motor (11), and a shaft-stop ring connection in the transition path between the drive motor shaft (11) and a shaft (14) carrying the starter pinion (2), characterized in that the abutment ring (13) forms a closed ring and is made of a shape memory material, the abutment ring (13) in its set position, axially on the shaft (14) corresponding to the stable phase of its material. 2) Starter device according to claim 1, characterized in that the shaft (14) has a groove for receiving the stop ring (13). 3) Starter device according to claim 1 or 2, characterized in that the stop ring (13) is made of a shape memory alloy, for example a nickel-titanium alloy (NiTi). 4) Starter device according to one of claims 1 to 3, characterized in that the stop ring (13) of the shaft-stop ring connection limits the axial movement of the starter gear (2). Starter device according to Claim 4, characterized in that the shaft of the shaft-stop ring connection is a pinion shaft (14) and the thrust ring (13) limits the axial movement of the pinion gear. starter (2) biased by a spring on the pinion shaft (14). Starter device according to Claim 4 or 5, characterized in that the end face of the starter gear (2) has a receiving groove through which the starter gear (2) overlaps the thrust ring (13). catch position. 7 °) starter device according to claim 6, characterized in that in the stop position, the end face of the starter gear (2) is flush with the front face of the pinion shaft (14). Starter device according to one of claims 1 to 7, characterized in that the shaft of the thrust ring-shaft connection is the shaft of the drive motor and the thrust ring (13) axially locks. the shaft in the drive motor housing. 9 °) Method for fixing a stop ring (13) on a shaft (14) in a starter device (1) according to one of claims 1 to 8, wherein the stop ring is slid (13). ) on the shaft (14) and when reaching the target axial position on the shaft (14) is heated to reduce the diameter of the stop ring (13). 10 °) Method of fixing a stop ring (13) on a shaft (14) in a starter device (1) according to one of claims 1 to 8, wherein the stop ring is enlarged (13). ) to slide on the shaft (14) and when in the setpoint axial position, returns to the stable outer diameter.