JP5883669B2 - Starter drive gear - Google Patents

Description

  The present invention relates to a starter drive gear, and more particularly to a starter ring gear welded to the outer periphery of a drive plate and a technology for suppressing tooth chipping and wear of a starter pinion meshing with the starter ring gear.

  In the case of an AT (automatic transmission) vehicle, a drive plate that transmits rotation from the engine to the torque converter by connecting the rear end of the crankshaft of the engine and a torque converter that is a power transmission device is used (see, for example, Patent Document 1). ).

  In general, as shown in FIG. 4, the drive plate has a plurality of circumferential directions in a state where the inner peripheral surface of the starter gear 26 for engaging the starter pinion 28 b with the outer peripheral surface of the drive plate 16 is engaged with the outer peripheral surface of the drive plate 16. It is constructed by welding points. In the figure, reference numeral 42 denotes a welded portion (weld bead). A starter drive gear 41 is formed by welding a plurality of locations in the circumferential direction in a state where the inner peripheral surface of the starter pinion 28 b meshed with the starter pinion 28 b is fitted to the outer peripheral surface of the drive plate 16. I will do it.

  In the starter drive gear 41, the starter ring gear 26 is manufactured by forming outer peripheral teeth on the outer peripheral surface of the annular member and subjecting the outer peripheral teeth to induction hardening and carburizing and quenching.

  By the way, after the starter drive gear 41 is manufactured as described above, a plurality of positions are welded between the starter drive gear 41 and the drive plate 16 while being fitted to the outer peripheral surface of the drive plate 16. Since heat at the time of welding is conducted to the outer peripheral teeth near the welded portion, the outer peripheral teeth are annealed, and the tooth surface hardness decreases.

JP 2011-252538 A

  In particular, in the conventional drive plate, since the intervals between the welded portions 42 are set at an equal pitch, the stop position is determined in accordance with the top dead center position of the compression process, so that the hardness of the starter gear 26 is reduced. There is a problem that the portion is arranged at the jumping position (meshing position) of the pinion, and tooth surface wear is promoted when the starter pinion jumps.

  In addition, in the case of an idle stop vehicle that has introduced an idle stop system as an engine start system, the engagement between the starter pinion 28b and the startering gear 26 is repeated each time the engine is started, and the number of meshes increases, so that the end surfaces of teeth and teeth It is expected that the startering gear 26 or the starter pinion 28b, which is generated at the time of collision, increases the chipping and wear of the teeth and is likely to cause engine start failure due to non-meshing (meshing failure).

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a starter drive gear that can suppress tooth surface wear of a starter ring gear due to a jump-in of a starter pinion and is suitable for an idle stop vehicle. To do.

In order to achieve the above object, the present invention includes a drive plate connected to a crankshaft of a three-cylinder engine , an inner peripheral surface fitted to the outer peripheral surface of the drive plate, and a plurality of locations in the circumferential direction being welded. , and a starter ring gear which is meshed with the starter pinion, in the starter drive gear meshing position of the starter pinion with respect to the starter ring gear at engine startup is three places, the drive plate has a crankshaft mounting holes in the circumferential direction The welds that are formed at six equal pitches and weld the drive plate and the startering gear are formed at eight irregular pitches along the circumferential direction, and the unequal pitch angles are 45 degrees, 45 degrees, 60 degrees, 30 degrees, 45 degrees, 45 degrees, 60 degrees, 30 degrees are arranged and formed, and the hardness decreases due to welding. Further, the starter pinion teeth are formed so as not to always jump into the tooth surface of the startering gear, and the drive plate is formed with a balance hole in order to suppress unbalance occurring at an unequal pitch .

  It is preferable that the welds are arranged symmetrically with respect to the rotation center of the drive plate.

  It is preferable that mounting portions for mounting the torque converter are provided at equal intervals in the circumferential direction on the drive plate, and the mounting portions are disposed between the welded portions adjacent to each other in the circumferential direction.

  According to the present invention, since the welds for welding the drive plate and the startering gear are formed at unequal pitches in the circumferential direction, the tooth surface wear due to the jumping of the starter pinion in the starter gear of the starter drive gear reduced in strength by annealing. This is particularly suitable for an idle stop vehicle in which the starter pinion and the startering gear are repeatedly engaged each time the engine is started.

It is the schematic which shows the structure of the engine and power transmission device of the vehicle to which this invention was applied. It is a figure which shows the starter drive gear of FIG. 1, (a) is a front view, (b) is XX sectional drawing of (a). It is sectional drawing which shows a part of torque converter containing the starter drive gear of FIG. It is a front view which shows the conventional starter drive gear.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is explained in full detail based on an accompanying drawing.

  As shown in FIG. 1, the engine 1 and the power transmission device 2 are also used for an FR (front engine, rear drive) type vehicle, but are particularly preferably used for an FF (front engine, front drive) type vehicle. Is. In addition to AT vehicles, it is also used for CVT (continuously variable transmission) vehicles. The output of the engine 1 as a driving power source constituted by an internal combustion engine is transmitted from the crankshaft 4 of the engine to the differential gear unit 12 through the torque converter 6, the automatic transmission 8, and the propeller shaft 10, respectively. Then, it is distributed from the differential gear unit 12 to the left and right drive wheels 14L, 14R.

  The torque converter 6 includes a pump impeller 6p connected to the crankshaft 4 via a disk-shaped drive plate 16, a turbine impeller 6t connected to the input shaft 18 of the automatic transmission 8, and a one-way clutch 20. And a stator impeller 6s that is prevented from rotating in one direction by the rotation of the pump impeller 6p that rotates together with the crankshaft 4 and is circulated in the torque converter 6 by the pump impeller 6p. Is transmitted to the turbine impeller 6t.

  The automatic transmission 8 supplies a plurality of planetary gear units and a transmission mechanism having a plurality of hydraulic engagement devices such as clutches and brakes, and the hydraulic engagement device for switching the engagement state of the hydraulic engagement devices. And a hydraulic speed control circuit for controlling the hydraulic pressure to be driven. A rotational speed ratio between the input shaft 18 and the output shaft 22, that is, a gear ratio, is any of a plurality of gear ratios set in advance according to the running state of the vehicle. Can be selectively switched to one.

  The power transmission device 2 includes an engine starting device 24 for assisting the operation of the engine 1 until the engine 1 rotates by itself to start the engine 1. The engine starter 24 has an annular shape with outer peripheral teeth 26a, has a starter ring gear 26 fixed to the outer peripheral surface of the drive plate 16, and a starter pinion 28b that can mesh with the outer peripheral teeth 26a. A starter motor 28 that rotationally drives the ring gear 26, and a magnet switch 30 that moves the starter pinion 28b between a meshing position that meshes with the starter ring gear 26 and a non-meshing position that does not mesh. In FIG. 1, the starter pinion 28 b shown by a broken line is positioned at a meshing position where the starter pinion 28 b meshes with the starter ring gear 26, and the starter pinion 28 b shown by a solid line in FIG. It is.

  The starter motor 28 has an output shaft 28a that can move in the axial direction parallel to the rotation center line (rotation center) C of the starter ring gear 26, as shown by an arrow a in FIG. 1, and a tip portion of the output shaft 28a. And a fixed starter pinion 28b. Further, the magnet switch 30 is provided so as to be movable in a direction parallel to the solenoid 30a and the output shaft 28a as shown by an arrow b in FIG. 1, and is attracted to the solenoid 30a side when the solenoid 30a is energized. And a movable iron core 30b.

  When the starter motor 26 is driven to rotate by the starter motor 28, the starter pinion 28b is energized by the solenoid 30a, and the movable iron core 30b is moved to the startering gear 26 side of the solenoid 30a. As shown in FIG. 2, the gear is moved to a meshing position where it meshes with the starter gear 26. The starter ring gear 26 is rotationally driven by the output torque of the starter motor 28 transmitted via the starter pinion 28b located at the meshing position.

  When the starter motor 28 is not driven to rotate by the starter motor 28, the starter pinion 28b stops energization of the solenoid 30a, and the output shaft 28a is moved to the opposite side of the starter gear 26 by the biasing force of the spring 32. As a result, as shown by the solid line in FIG. 1, it is moved to a non-meshing position where it does not mesh with the startering gear 26.

  The engine starting device 24 configured as described above operates the starter motor 28 at the time of starting the engine to rotate the crankshaft 4 via the starter pinion 28b and the startering gear 26, and the rotational speed of the engine 1 is determined in advance. The engine speed is increased to a predetermined engine ignition speed.

  As shown in FIGS. 2 to 3, the drive plate 16 has a protrusion 4 a in which a center hole 32 formed concentrically with the rotation center line C is formed on one end surface of the crankshaft 4 concentrically with the rotation center line C. Are fastened to the crankshaft 4 by a plurality of bolts 34. Further, the outer peripheral portion of the drive plate 16 is fastened to the cover 6 a of the torque converter 6 by a plurality of bolts 36. The drive plate 6 is provided with a crankshaft mounting hole 38 and a cover mounting hole 40 for the torque converter 6.

  The starter gear 26 is manufactured by forming a plurality of outer peripheral teeth 26a parallel to the rotation center line C on the outer peripheral surface of the annular member, and subjecting the outer peripheral teeth 26a to induction hardening. The startering gear 26 manufactured in this way is fixed to the drive plate 16 at a plurality of locations, for example, by MIG welding while being fitted to the outer peripheral surface of the short cylindrical portion 16a of the drive plate 16. In this manner, the inner peripheral surface 26b of the starter ring gear 26 meshed with the starter pinion 28b is fitted to the outer peripheral surface 16b of the drive plate 16 connected to the crankshaft 4 of the engine 1 in a plurality of positions in the circumferential direction. The starter drive gear 41 is manufactured by welding at a welding portion 42.

  By the way, the stop position of the drive plate 16 stops when the piston of the engine 1 comes to the top dead center of the compression process. For example, there are three stop positions for a three-cylinder and six-cylinder engine, and two stop positions for a four-cylinder engine. Therefore, the position where the starter pinion 28b jumps is also determined by the piston stop position.

  However, in the conventional starter drive gear, since the intervals between the welded portions 42 are set at an equal pitch, there is a high possibility that the position of the welded portion 42 is arranged at the jumping position of the starter pinion 28b. There has been a problem that tooth surface wear at the meshing position where the reduction occurs is promoted.

  Therefore, in this embodiment, in order to solve such a problem, it is opposite to the side surface 16m facing the starter pinion 28b located at the non-meshing position in the direction parallel to the rotation center line C. The other side surface 16n is welded to the drive plate 16 at eight positions at an unequal pitch in the circumferential direction around the rotation center line C. As shown in FIGS. 2 to 3, welded portions (weld beads) 42 for welding the drive plate 16 and the startering gear 26 are formed at unequal pitches in the circumferential direction.

  Specifically, as shown in FIG. 2, the positions of the welded portion 42a and the welded portion 42a ′ paired with the welded portion 42a conventionally arranged at the jumping position of the starter pinion 28b as shown in FIG. 4 are clockwise as shown in FIG. Is shifted by a predetermined angle (for example, 15 degrees which is an angle of one third of 45 degrees which is an equal part of 360 degrees), and thereby four parts which are the parts of the angle α (45 degrees) so far In addition to the above, the inequality has two places that are a part of an angle β (60 degrees) wider than the angle α so far and two places that are a part of an angle γ (30 degrees) narrower than the angle α so far. It is said to be a pitch.

  As described above, the intervals between the startering gear 26 and the welded portion 42 of the drive plate 16 are set to unequal pitches, so that the teeth of the starter pinion 28b do not always jump into the tooth surface of the startering gear 26 whose hardness is reduced by welding of the welded portion 42. The tooth surface wear of the starter ring gear 26 due to the jump-in of the starter pinion 28b can be suppressed.

  Further, since the cover mounting hole 40 as the mounting portion of the torque converter 6 is also disposed between the welded portions 42 adjacent in the circumferential direction, the force applied to the cover mounting hole 40 is reduced by the welded portion 42 due to the hardness of the starter gear. It is possible to avoid acting directly on the part, and the deformation amount of the drive plate 16 and the startering gear 26 can be suppressed, and the necessary accuracy (dimension, runout, flatness, parallelism) can be ensured.

  By the way, if the interval between the welds 42 adjacent to each other in the circumferential direction is wide, the natural frequency of the drive plate 16 is reduced, and when the engine rotational speed is less than or equal to the resonance frequency, the drive plate may be damaged. There is.

  Therefore, the angle between the weld portions 42 adjacent in the circumferential direction with respect to the center of the drive plate 16 is set to α = 45 degrees, β = 60, γ = 30 degrees, and the welding interval is set to be larger than 0 degree and less than 60 degrees. Therefore, the natural frequency of the drive plate 16 becomes higher than the engine operating speed, and resonance can be avoided.

  Further, since the welded portion 42 is arranged point-symmetrically with respect to the rotation center (rotation center line) C of the drive plate 16, unbalance can be eliminated and vibration associated with rotation of the drive plate 16 is suppressed. be able to. The amount of unbalance in the case of the present embodiment is substantially the same as that of a conventional product in which welds are arranged at an equal pitch.

  Note that the unbalance amount specified in the design drawing will be exceeded due to the variation in weight due to welding, the variation in the weight of the drive plate itself, and the variation in the weight of the starter gear itself. The plate is preferably provided with a balance hole 44 or a balance weight. Further, it is preferable that an opening 46 is provided between the crankshaft mounting hole 38 and the cover mounting hole 40 in the drive plate 16 so as to give the drive plate 16 flexibility.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-described embodiments, and various design changes and the like can be made without departing from the gist of the present invention. is there.

1 Engine 4 Crankshaft 16 Drive plate 26 Starter ring gear 28b Starter pinion 40 Mounting hole (mounting part)
41 Starter drive gear 42 Welded part

Claims (3)

A drive plate connected to a crankshaft of a three-cylinder engine, and a startering gear having an inner peripheral surface fitted to the outer peripheral surface of the drive plate and welded at a plurality of locations in the circumferential direction and meshed with a starter pinion In the starter drive gear in which the starter pinion meshes with the starter gear at the time of starting the engine at three positions ,
Crankshaft mounting holes are formed in the drive plate at six equal pitches in the circumferential direction, and welds for welding the drive plate and the startering gear are formed at eight irregular pitches along the circumferential direction. In addition, the tooth surface of the startering gear whose unequal pitch angles are arranged and formed in the order of 45 degrees, 45 degrees, 60 degrees, 30 degrees, 45 degrees, 45 degrees, 60 degrees and 30 degrees and whose hardness is reduced by welding. The starter drive gear is formed so that the teeth of the starter pinion do not always jump in, and a balance hole is formed in the drive plate in order to suppress unbalance occurring at an unequal pitch . Starter drive gear of claim 1 Symbol mounting the weld are arranged in point symmetry relative to the center of rotation of the drive plate. The drive plate mounting portion for mounting the torque converter is provided at equal intervals in the circumferential direction, the portion with said mounting is in claim 1 or 2 is placed between the welded portion adjacent to the circumferential direction The starter drive gear described.

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