JP2005264905A - Pinion shift type starter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pinion shift type starter device having a reduced size while securing a sufficient meshing width between a pinion and a ring gear, and having simple construction for sufficiently resisting to repetitive operation with no excessive load produced. <P>SOLUTION: The pinion shift type starter device has such a mechanism that a rocking lever 33 is driven by a magnetic switch 3 for meshing the pinion 5 connected to an output shaft 4 of a starter motor 2 movably forward and backward with the ring gear 9 connected to an engine. The lever 33 has a lever ratio R continuously changed with its rotation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pinion shift starter device for starting an engine.

  Generally, a pinion shift starter device for starting an engine is a ring gear in which a pinion connected to an output shaft of a starter motor is connected to an engine by driving a lever provided to be swingable by a magnetic drive mechanism. To bite into.

  Here, in this conventional pinion shift type starter device, the fulcrum portion of the lever for shifting the pinion is formed in a cylindrical shape, and when a force is applied to the end of the lever on the lever point side by the magnetic drive mechanism, Rotates around the cylindrical fulcrum and moves the pinion to a position where it engages with the ring gear.

  As described above, in the conventional apparatus, the lever always rotates around the cylindrical fulcrum portion. Therefore, the distance from the force point side end of the lever to the fulcrum center is L1, and the distance from the fulcrum center to the end of the action point side. Assuming that the distance to the portion is L2, the lever ratio R (= L2 / L1) is always substantially constant, and is generally set to R = 1.5-2.

  In the conventional device, in order to ensure the engagement between the pinion and the ring gear, if the pinion is moved largely with the lever ratio R kept constant, the movement amount of the plunger constituting the magnetic drive mechanism is also increased. In other words, the entire magnetic drive mechanism is enlarged, and the demand for downsizing is lost. In order to increase the amount of movement of the pinion without changing the amount of movement of the plunger from the conventional one, it is conceivable to increase the lever ratio R, for example. However, in that case, a large force is always required to move the pinion forward, and as a result, the entire magnetic drive mechanism is enlarged, and the demand for downsizing is lost.

  Therefore, in the prior art, in order to reduce the size of the device while ensuring a sufficient amount of movement of the pinion, for example, a first fulcrum portion that deviates the lever toward the power point side and a first fulcrum portion that deviates toward the action point side. 2 when the pinion approaches the ring gear, it rotates around the second fulcrum, and when the pinion moves forward and meshes with the ring gear, it rotates around the first fulcrum. What has been proposed is proposed (see, for example, Patent Documents 1 and 2).

  In the case of the configurations shown in these Patent Documents 1 and 2, since the lever ratio is small at the initial stage of operation of the starter device, the load applied to the magnetic drive mechanism can be small, and the stage where the pinion moves forward and meshes with the ring gear. Then, since the lever ratio becomes large, a sufficient amount of movement of the pinion can be secured and the gear can be reliably engaged with the ring gear.

Japanese Patent No. 25222326 JP-A-60-27780

  However, in the configuration as described in each of the above Patent Documents 1 and 2, the switching from the second fulcrum to the first fulcrum as the rotation axis of the lever is abruptly performed. Excessive force is applied to the first fulcrum during switching. For this reason, the lever needs to secure sufficient strength to withstand repeated operations in advance, which increases the cost of the device. In particular, in the one described in Patent Document 1, in order to support the lever so as to be swingable, a holder having first and second support holes corresponding to the first and second fulcrum portions is required. The structure of the supporting part is complicated and the assembling work becomes complicated.

  The present invention has been made to solve the above-described problems, and can reduce the size of the apparatus while ensuring a sufficient engagement width between the pinion and the ring gear, and has an excessive load while having a simple configuration. It is an object of the present invention to provide a pinion shift type starter device having a lever that can sufficiently withstand repeated operations without causing any trouble.

  In order to achieve the above object, in the pinion shift starter device of the present invention, a swingable lever is driven by a magnetic drive mechanism and is connected to the output shaft of the starter motor so as to be able to advance and retract. Further, the lever is configured to mesh with a ring gear connected to the engine, and the lever is configured such that the lever ratio continuously changes in accordance with the amount of rotation.

  According to the pinion shift type starter device of the present invention, since the lever ratio is small at the initial stage of operation start of the starter device, the load applied to the magnetic drive mechanism can be small. When the pinion moves forward and meshes with the ring gear, the lever ratio increases, so the load applied to the magnetic drive mechanism increases somewhat. However, the pinion is securely meshed with the ring gear to ensure a sufficient amount of movement of the pinion. be able to.

  Thus, since the amount of rotation of the lever until the pinion meshes with the ring gear may be small, the moving distance of the plunger or the like constituting the magnetic drive mechanism may be small. In addition, since the lever ratio is small at the initial stage of starting the operation of the starter device, the load applied to the magnetic drive mechanism can be reduced, so that the magnetic drive mechanism can be reduced in size.

  Furthermore, the lever ratio does not change discontinuously as in the prior art, but changes smoothly and continuously with the rotation of the lever, so an excessive load is suddenly applied to the lever when the lever ratio is switched. Will not occur. For this reason, it is possible to sufficiently withstand the repeated operation of moving the pinion back and forth, and to extend the life.

Embodiment 1 FIG.
1 and 2 are cross-sectional views showing the configuration of the pinion shift starter device according to Embodiment 1 of the present invention. FIG. 1 shows an operation stop state, and FIG. 2 shows a state where the pinion is engaged with the ring gear.

  The pinion shift starter device according to the first embodiment includes a starter motor 2 and a magnetic switch 3 that use a battery 1 as a power source. The output shaft 4 of the starter motor 2 is spline-fitted in a state where the pinion 5, the overrunning clutch 6, and the flange piece 7 are integrated, and is provided so as to be able to advance and retreat along the output shaft 4. The pinion 5 meshes with a ring gear 9 formed on the outer periphery of a flywheel connected to the engine in a state where the pinion 5 has advanced along the output shaft 4.

  The magnetic switch 3 corresponds to the magnetic drive mechanism in the claims, and has a core switch 12 on the fixed side and a plunger 13 on the movable side, and a plunger spring 14 is interposed between the both 12 and 13. The exciting coils 17 and 18 are wound around the outer circumferences of the core switch 12 and the plunger 13, respectively. The exciting coils 17 and 18 are connected to the battery via the key switch 19.

  In the core switch 12, a contact shaft 22 is slidable in the center of the base 21 along the axial direction, and a movable contact 23 is attached to the contact shaft 22. The fixed contacts 24 a and 24 b are arranged to face the movable contact 23.

  On the other hand, the plunger 13 is provided at the center of the cylinder 25 so that a slide rod 26 is slidable along the axial direction. One end of the slide rod 26 protrudes outward of the cylinder 25, and a hook 27 is formed at the protruding portion. Has been. A lever spring 28 is coaxially interposed between the inner periphery of the cylinder 25 and the outer periphery of the slide rod 26, and is prevented from coming out by a stopper 29 attached to the end of the cylinder 25.

  Further, a fulcrum portion 33b of the lever 33 is swingably supported between the plate 32 and the plate 32 disposed so as to face the front bracket 8. One end portion 33a on the force point side of the lever 33 is connected to the plunger 13. The other end 33 c which is engaged with the hook 27 and which is the operating point side of the lever 33 is fitted between the overrunning clutch 6 and the flange piece 7.

  In particular, in the first embodiment, the fulcrum portion 33b of the lever 33 supported between the front bracket 8 and the plate 32 has a distance between the front bracket 8 and the plate 32 that is determined by the curvatures of the left and right end surfaces. It is previously formed in an arc shape that is larger than the curvature of a circle having a diameter. As a result, as will be described in detail later, the lever ratio R continuously changes as the lever 33 rotates.

  In the pinion shift starter device configured as described above, in the initial stop state shown in FIG. 1, the plunger 13 of the magnetic switch 3 is pressed in a direction away from the core switch 12 by the plunger spring 14. It is held at a position away from the ring gear 9.

  Next, as shown in FIG. 2, when the key switch 19 is turned on, the excitation coils 17 and 18 of the magnetic switch 3 are energized from the battery 1 and the excitation coils 17 and 18 are excited. The lever 33 that is attracted toward the core switch 12 against the spring force of the plunger spring 14 and engaged with the hook 27 at the tip of the slide rod 26 of the plunger 13 is pulled. Accordingly, the lever 33 rotates counterclockwise in the drawing with the fulcrum portion 33b as a rotation axis, and the end portion 33c on the operating point side of the lever 33 pushes the overrunning clutch 6. Therefore, the pinion 5 Advances along the output shaft 4 of the starter motor 2, and the pinion 5 comes into contact with the ring gear 9.

  Even if the pinion 5 is in contact with the ring gear 9 and the teeth of both the pins 5 and 9 are not yet engaged, the lever 13 continues to be sucked toward the core switch 12 while the lever 33 stops rotating. 28 is compressed and the pinion 5 is urged to the ring gear 9 side via the lever 33. When the cylinder 25 of the plunger 13 comes into contact with the base 21 of the core switch 12, the contact shaft 22 is pushed by the end face of the cylinder 25, so that the movable contact 23 provided on the contact shaft 22 becomes fixed contacts 24a and 24b. The starter motor 2 is started in contact with. When the starter motor 2 is started, the rotational force is transmitted from the output shaft 4 to the pinion 5, so that the pinion 5 starts to rotate. As a result, the pinion 5 meshes with the ring gear 9, and the ring gear 9 is rotationally driven to start the engine.

  Thereafter, when the key switch 19 is turned off, the energization to the respective excitation coils 17 and 18 of the magnetic switch 3 is stopped, so that the plunger 13 is separated from the core switch 12 by the spring force of the plunger spring 14 to the original position. Return. Along with this, the lever 33 rotates clockwise in the figure, and the end 33c on the action point side of the lever 33 pushes the flange piece 7, so that the pinion 5 moves backward along the output shaft 4 together with the overrunning clutch 6, The pinion 5 is released from the ring gear 9.

  FIG. 3 is a characteristic diagram showing the relationship of the lever ratio R to the movement distance X of the plunger 13 in the pinion shift starter device of the first embodiment, and FIG. 4 is a relationship of the movement distance Y of the pinion 5 to the movement distance X of the plunger 13. FIG.

  Here, when the length from the force point A to the fulcrum B of the lever 33 is L1, and the length from the operating point C to the fulcrum B of the lever 33 is L2, the fulcrum of the lever 33 is shown by a broken line in FIG. In the conventional structure in which the portion 33b is cylindrical, the lever ratio R (= L2 / L1) hardly changes with respect to the movement distance X of the plunger 13 (which corresponds to the rotation amount of the lever 33). For this reason, the movement distance Y of the pinion 5 changes linearly according to the movement distance X of the plunger 13 as shown by the broken line in FIG.

  On the other hand, in the first embodiment, as shown by the solid line in FIG. 3, the lever ratio R changes to a downwardly parabolic shape with respect to the movement distance X of the plunger 13. In other words, the fulcrum portion 33b of the lever 33 is formed in an arc shape in advance so that the respective curvatures of its left and right end faces are larger than the curvature of a circle whose diameter is the distance between the front bracket 8 and the plate 32. As the lever 33 rotates counterclockwise and the amount of rotation increases, the position of the fulcrum B continuously shifts from the output shaft 4 side to the magnetic switch 3 side. As a result, as the pinion 5 moves toward the ring gear 9, the lever ratio R gradually increases, and the ratio of the movement distance Y of the pinion 5 to the movement distance X of the plunger 13 increases.

  Therefore, as shown in FIG. 4, when the movement distance of the pinion 5 necessary for the pinion 5 to mesh with the ring gear 9 is assumed to be Yo, the movement of the plunger 13 required to move the pinion 5 to this movement distance Yo. In contrast to the conventional distance of X2, the distance of X11 (<X2) is sufficient in the first embodiment.

  Thus, the pinion shift starter device of the first embodiment requires a small load applied to the magnetic switch 3 because the lever ratio R is small at the initial stage of operation start. In addition, as the pinion 5 moves toward the ring gear 9, the lever ratio R gradually increases. For this reason, the amount of rotation of the lever 33 until the pinion 5 meshes with the ring gear 9 is small, and the movement distance X of the plunger 13 is also smaller than before (X11 <X2). Thereby, size reduction of the magnetic switch 3 can be achieved. Moreover, since the amount of contraction of the lever spring 28 when the plunger 13 moves to the core switch 12 side is small, it is advantageous in terms of the fatigue life of the spring 28.

  Further, when the pinion 5 moves forward and meshes with the ring gear 9, the lever ratio R is increased, so that the load applied to the magnetic switch 3 is somewhat increased, but the ring gear 9 can be secured in order to ensure a sufficient amount of movement of the pinion 5. Can be reliably engaged with each other.

  Moreover, the lever ratio R does not change discontinuously as in the prior art, but changes smoothly and continuously with the rotation of the lever 33. Therefore, the lever ratio R is excessive when the lever ratio R is switched. Load does not occur suddenly. For this reason, it is possible to sufficiently withstand the repeated operation of moving the pinion 5 back and forth, and to extend the life.

Embodiment 2. FIG.
FIG. 5 is a cross-sectional view showing the configuration of the pinion shift starter device according to the second embodiment of the present invention, and the same reference numerals are given to the components corresponding to the configurations of the first embodiment shown in FIGS. Attached.

  The feature of the second embodiment is that the shape of the fulcrum portion 33b of the lever 33 is not a simple arc shape as in the first embodiment but a predetermined cam shape.

  As described above, when the shape of the fulcrum portion 33b of the lever 33 is set to a predetermined cam shape, as shown by a solid line in FIG. Can be touched. Thereby, after the pinion 5 is pressed against the ring gear 9 sufficiently stably by the lever spring 28, the contact of the magnetic switch 3 is closed and the starter motor 2 starts to rotate. It can be carried out.

In addition, when the movement distance of the pinion 5 necessary for the pinion 5 to mesh with the ring gear 9 is assumed to be Yo, the movement distance of the plunger 13 required to move the pinion 5 to this movement distance Yo is conventionally X2. In contrast to the distance required, the distance of X12 (<X2) is required in the second embodiment, and the magnetic switch 3 can be downsized.
Other configurations and operational effects are the same as those of the first embodiment, and thus detailed description thereof is omitted here.

  There is no particular restriction on the cam shape at the fulcrum 33b of the lever 33 in the second embodiment, and the lever is such that the relationship of the movement distance Y of the pinion 5 to the movement distance X of the plunger 13 draws a desired characteristic curve. Any shape can be set as long as the ratio changes continuously.

  In the first and second embodiments, the lever spring 28 is provided in the cylinder 25 of the plunger 13. However, the present invention is not limited to this, and the lever spring 28 may be provided on the fulcrum 33b side or the pinion 5 side of the lever 33. .

It is sectional drawing which shows the structure in the operation | movement stop state of the pinion shift starter apparatus in Embodiment 1 of this invention. FIG. 3 is a cross-sectional view showing the configuration of the pinion shift starter device according to Embodiment 1 of the present invention in a state where the pinion meshes with the ring gear. In the pinion shift type starter device of Embodiment 1 of the present invention, it is a characteristic diagram showing the relationship of the lever ratio R with respect to the movement distance X of the plunger. In the pinion shift type starter device of Embodiment 1 of the present invention, it is a characteristic diagram showing the relationship of the movement distance Y of the pinion with respect to the movement distance X of the plunger. It is sectional drawing which shows the structure in the operation | movement stop state of the pinion shift type starter apparatus in Embodiment 2 of this invention. In the pinion shift starter device of Embodiment 2 of the present invention, it is a characteristic diagram showing the relationship of the movement distance Y of the pinion with respect to the movement distance X of the plunger.

Explanation of symbols

2 starter motor, 3 magnetic switch (magnetic drive mechanism),
4 Output shaft, 5 pinion, 9 ring gear, 33 lever.

Claims (2)

In a pinion shift starter device in which a lever provided in a swingable manner is driven by a magnetic drive mechanism and a pinion connected to an output shaft of a starter motor is engaged with a ring gear connected to an engine. A pinion shift type starter device characterized in that the lever ratio is continuously changed according to the rotation amount. 2. The pinion shift starter device according to claim 1, wherein the lever ratio continuously changes according to the amount of rotation, wherein the fulcrum portion of the lever is formed in a cam shape.

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