JPH05106537A - Starter - Google Patents

Abstract

PURPOSE:To set a pinion gear to be engaged with a ring gear easily by providing a drive spring held between a plunger and a plunger shaft in such a way that its spring force is increased in stages corresponding to an increase ratio of a plunger attracting force of a magnet coil. CONSTITUTION:A pinion gear 9 for transmitting rotation force of a starter motor 2 to a ring gear 8, and a magnet coil 13 which generates an excitation force when it is energized are provided. A plunger 14 disposed along the same axis as the pinion gear 9 and attracted toward the pinion gear 9 by a magnetomotive force of the magnet coil 13, and a plunger shaft 15 disposed along the same axis as the plunger 14 are provided. Drive springs 16, 17 held between the plunger 14 and the plunger shaft 15 are set in such a way that their spring force is increased in stages corresponding to an increase of a plunger attracting force of the magnet coil 13. An engagement property of the pinion gear 9 with the ring gear 8 can thus be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reduction type starter in which a pinion gear and a plunger shaft are arranged on the same axis.

[0002]

2. Description of the Related Art Conventionally, a pinion gear to which rotation of a starter motor is transmitted, a pinion spring for easily engaging the pinion gear with a ring gear of an internal combustion engine, a plunger shaft for pushing the pinion gear to the ring gear side, and a plunger shaft A starter in which a plunger that holds the rear end portion slidably, a magnet coil that attracts the plunger when an electric current flows, and a drive spring held by the plunger and the plunger shaft inside the plunger are arranged on the same axis. It has been known. A movable contact, which comes into contact with the fixed contact when moved to the pinion gear side due to the magnetomotive force of the magnet coil, and a contact pressure spring which gives the movable contact a contact pressure to the fixed contact, are attached to the outer circumference of the plunger. ..

[0003]

Further, conventionally, in the reduction type starter, as shown in the graph of FIG.
There is a predetermined condition between the plunger attraction force of the magnet coil and the pinion spring, drive spring and contact pressure spring. That is, in the 12V starter, since the operating voltage of the magnet switch is set to about 6V, the plunger attraction force of the magnet coil is set to exceed the spring force of the drive spring in the vicinity of the point a. However,
In the conventional deceleration type starter, when the contact pressure spring acts, that is, when the pinion gear contacts the ring gear and is pressed by the spring force of the drive spring, the plunger attraction force of the magnet coil is as shown in the graph of FIG. It is significantly higher than the spring force of the drive spring shown by the dashed line. As a result, at the position where the pinion gear comes into contact with the ring gear and meshes with each other, the force for pushing the pinion gear toward the ring gear side is not sufficiently exerted, and there is a problem in that the meshability of the pinion gear with the ring gear decreases. An object of the present invention is to provide a starter in which the relationship between the plunger attraction force of the magnet coil and the spring force of the drive spring is improved to improve the meshability of the pinion gear with the ring gear.

[0004]

According to the present invention, a pinion gear for transmitting a rotational force of a starter motor to a ring gear of an internal combustion engine, a magnet coil for generating a magnetomotive force when energized, and a pinion gear arranged on the same axis center. A plunger that is attracted to the pinion gear side by the magnetomotive force of the magnet coil, a plunger shaft that is arranged on the same axis as the plunger and that pushes the pinion gear toward the ring gear side, and the plunger and the plunger shaft. A technical means including a drive spring or a plurality of drive springs, which are held in between and are set so that the spring force is increased stepwise in accordance with the increasing rate of the plunger attraction force of the magnet coil, is adopted.

[0005]

In the present invention, when the magnet coil is energized,
The magnetomotive force of the magnet coil attracts the plunger toward the pinion gear. The plunger attraction force of the magnet coil increases as the plunger approaches the pinion gear side. On the other hand, the drive spring acts in accordance with the movement of the plunger toward the pinion gear side after the pinion gear contacts the ring gear, and presses the plunger shaft toward the pinion gear side. Therefore, the plunger shaft pushes the pinion gear toward the ring gear side, and the pinion gear engages with the ring gear. In the present invention,
The drive spring held between the plunger and the plunger shaft sets one or a plurality of drive springs so as to increase the spring force stepwise in accordance with the increasing rate of the plunger attraction force of the magnet coil. Therefore, when the pinion gear contacts the ring gear and the plunger is attracted to the meshing position, the spring force of the drive spring follows the increase rate of the plunger attracting force of the magnet coil in a stepwise manner. As a result, at the position where the pinion gear abuts on the ring gear and meshes with the ring gear, a sufficient force for the drive spring to push the pinion gear to the ring gear side through the plunger shaft is obtained, so that the pinion gear is easily engaged with the ring gear.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A starter according to the present invention will be described based on an embodiment shown in FIGS. FIG. 1 is a diagram showing a decelerating starter for an automobile. The automobile deceleration starter 1 includes a starter motor 2 and a magnet switch 3.
An idler gear 4 is connected to an armature (not shown) of the starter motor 2 to reduce the speed of rotation of the armature. A clutch gear 7 that transmits the rotational force of the starter motor 2 to the pinion shaft 6 via a spline shaft 5 is connected to the idle gear 4. Further, the pinion shaft 6 is provided with a pinion gear 9 that engages with the ring gear 8 of the internal combustion engine at the tip end thereof,
The rotational force of the starter motor 2 is transmitted to this pinion gear 9. A return spring 10 is provided between the inner circumference of the spline shaft 5 and the outer circumference of the pinion shaft 6 to return the pinion shaft 6 from the moving position to the stationary position. Further, a pinion spring 11 is provided between the outer circumference of the pinion shaft 6 and the inner circumference of the pinion gear 9 to facilitate the engagement of the pinion gear 9 with the ring gear 8.
Are arranged.

The magnet switch 3 includes a frame 12,
The magnet coil 13, the plunger 14, the plunger shaft 15, and the first and second drive springs 16,
It is composed of 17 etc. The frame 12 is connected between the front housing 18 and the switch cover 19. This frame 12 has a front housing 18
At the same time, the spline shaft 5 is rotatably supported via bearings 20 and 21. Magnet coil 13
Is composed of a pull-in coil wound with a thick wire and a holding coil wound with a thin wire and having a weaker magnetomotive force than the pull-in coil, and is wound around a bobbin 22 fitted to the outer circumference of the plunger shaft 15. As shown in the graph of FIG. 3, the plunger attraction force of the magnet coil 13 increases as the plunger 14 strokes toward the pinion gear 9. The plunger attraction force of the magnet coil 13 is set to exceed the spring force of the first drive spring 16 near the point a (see the graph in FIG. 3) at an operating voltage of 6V.

The plunger 14 is arranged on the same axis as the pinion gear 9 and moves to the pinion gear 9 side by a predetermined plunger stroke L. The plunger 14 is
An axial hole 23 for holding the first and second drive springs 16 and 17 is formed inside. As shown in FIG. 2, a washer 25 having a burring portion 24 is joined to the rear end of the axial hole 23 by welding or the like.
Further, the insulating bush 2 is provided on the outer periphery of the plunger 14.
A movable contact 28 sandwiched between 6 and 27 is fixed, and between the bush 27 and the outer peripheral portion of the washer 25, a contact pressure spring which gives the movable contact 28 a contact pressure to a fixed contact 29 fixed to the frame 12. 30 are retained. When the movable contact 28 and the fixed contact 29 come into contact with each other, the battery and the starter motor 2 are electrically connected.

The plunger shaft 15 is arranged on the same axis as the pinion gear 9, and has a return spring 31 on the outer circumference for returning the plunger 14 from the moving position to the stationary position. Further, the tip end portion of the plunger shaft 15 is brought into contact with the pinion shaft 6 via the steel ball 32. Further, the rear end portion of the plunger shaft 15, that is, the flat portion 33 of the plunger shaft 15 is slidably fitted in the axial hole 23 so that the plunger 1
It is held at 4.

The first drive spring 16 has an axial hole.
23, the tip of the plunger shaft 15
It is held by the stopper 33 and its rear end is held by the washer 25.
The plunger shaft 15 and the pinion shaft 6
The pinion gear 9 is pressed to the ring gear 8 side via
The pushing force works. Second drive spring 17
Has a predetermined axial dimension from the first drive spring 16.
Dimension L₁(See Figure 3)
The rear end of the washer is fitted to the burring portion 24.
25, and the tip of the plunger shaft 15
When it comes into contact with the stopper portion 33, the plunger shaft 15 and
Ring the pinion gear 9 through the pinion shaft 6.
The pushing force acts so as to push the yarn 8 side. This is
The first and second drive springs 16 and 17 are
Plunger by operating voltage (6V) of net coil 13
Lower than the attractive force, and the plan of the magnet coil 13
It will increase in two steps according to the increase rate of the suction force.
The spring force is set for each. Sanawa
The first and second drive springs 16 and 17 are shown in FIG.
As indicated by the solid line in the graph
Plunger 14 up to the point where point 17 acts (point b)
Stroke (L₁+ L ₂) And then the first drive sp
Operate the ring 16 to move from point b to the second drive
By making the pulling 17 act in steps,
Drive spring splung at the end of Jastroke L
Fing force₁To F₂By increasing to
The pushing force of the on-gear 9 to the ring gear 8 is set by the plunger.
Spring force is set to follow the suction force P step by step.
It is fixed.

The operation of the automobile deceleration type starter 1 will be described with reference to FIGS. When an operating voltage of 6 V or more is applied to the magnet coil 13 by turning on a starter switch (not shown), a magnetomotive force is generated in the magnet coil 13, and the magnetomotive force of the magnet coil 13 causes the plunger 14 to move to the pinion gear 9. Is sucked to the side. At this time, when the plunger 14 is sucked by the plunger stroke L ₂ (see the graph in FIG. 3), that is, by the gap between the ring gear 8 and the pinion gear 9, the pinion gear 9 contacts the ring gear 8. Then, the spring force of the first drive spring 16 causes the pinion spring 11 to bend, and the plunger 14 moves toward the pinion gear 9 side by the plunger stroke L ₃ (see the graph in FIG. 3).

Further, the plunge of the magnet coil 13
The first drive spring 16 bends due to the suction force,
Axial dimension of the first and second drive springs 16 and 17
Difference L₁Point b (Fig.
(Refer to the graph of 3), the tip of the second drive spring 17
The end contacts the flat portion 33 of the plunger shaft 15.
It Therefore, in addition to the first drive spring 16, the second drive spring 16
The drive spring 17 also starts to operate, and the pinion gear 9
The pushing force to the ring gear 8 is gradually increased. It
In addition, the plunger 14 has a plunger stroke L._FourSucking
When pulled, the first and second drive springs 16, 17
Bends and moves at point c (see graph in Figure 3)
28 contacts the fixed contact 29, and this point c (see FIG. 3)
The contact pressure spring 30 starts to work from the graph
It Next, the contact pressure spring 30 is plunger adjusted.
Rourke L_Five(Refer to the graph in FIG. 3) Point d that only bends
The plunger 14 moves to (see the graph in FIG. 3).
And the attraction of the plunger 14 by the magnet coil 13
(Plunger stroke L) is completed. At this time,
The pushing force of the union gear 9 to the ring gear 8 is F. ₂(Figure
(See graph 3).

On the other hand, when the movable contact 28 comes into contact with the fixed contact 29, the battery and the starter motor 2 are electrically connected, so that the starter motor 2 starts to rotate. Then, the rotational force of the starter motor 2 is transmitted to the pinion gear 9 via the idle gear 4, the clutch gear 7, the spline shaft 5, and the pinion shaft 6, and the pinion gear 9 starts rotating in a state of being in contact with the ring gear 8. Then, when the pushing synthetic force F ₂ (see the graph in FIG. 3) is applied to the pinion gear 9, the pinion gear 9 meshes with the ring gear 8 and the internal combustion engine is started. That is, in this embodiment, as shown in the graph of FIG. 3, the operating voltage 6V of the magnet coil 13 is secured from the rising curve of the plunger attraction force of the magnet coil 13, and the plunger attraction force of the magnet coil 13 has a margin. After the generated plunger stroke L ₁ , the second drive spring 17 is also acted in addition to the first drive spring 16.
A combined pushing force F ₂ that pushes the pinion gear 9 to the ring gear 8 can be obtained. Therefore, the pinion gear 9
The pushing force to the ring gear 8 becomes F _{2 as} compared with F _{1 of the} prior art, and can be increased so as to approach the plunger attraction force of the magnet coil 13. As a result, after the pinion gear 9 comes into contact with the ring gear 8, a sufficient pushing force of the pinion gear 9 to the ring gear 8 by the first and second drive springs 16 and 17 can be obtained. Therefore, the meshability of the pinion gear 9 with the ring gear 8 can be significantly improved without increasing the operating voltage of the reduction gear starter 1 for an automobile.

In this embodiment, the drive spring is composed of the two first and second drive springs 16 and 17, but the drive spring may be composed of three or more drive springs. In order to increase the spring force of one or more drive springs in two or more steps corresponding to the increase rate of the plunger attracting force of the magnet coil, as shown in FIG. The spring constant may be set to be changed stepwise.

[0015]

According to the present invention, after the pinion gear comes into contact with the ring gear, a sufficient force for pushing the pinion gear toward the ring gear by the drive spring can be obtained, so that the pinion gear is easily engaged with the ring gear. It is possible to remarkably improve the meshing property.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a reduction type starter for an automobile.

FIG. 2 is a cross-sectional view showing a main part of a magnet switch.

FIG. 3 is a graph showing a relationship between a pushing force of a pinion gear to a ring gear and a plunger stroke.

FIG. 4 is a schematic diagram showing a winding method having a coarse and fine structure in which a spring constant of a drive spring is changed stepwise.

[Explanation of symbols]

 1 Automotive Deceleration Starter 2 Starter Motor 3 Magnet Switch 8 Ring Gear 9 Pinion Gear 13 Magnet Coil 14 Plunger 15 Plunger Shaft 16 First Drive Spring 17 Second Drive Spring

Claims (1)

[Claims] 1. A pinion gear for transmitting a rotational force of a starter motor to a ring gear of an internal combustion engine, a magnet coil for generating a magnetomotive force when energized, and a pinion gear on the same axis as the pinion gear. A plunger that is disposed and is attracted to the pinion gear side by the magnetomotive force of the magnet coil; and (d) a plunger shaft that is disposed on the same axis as the plunger and that pushes the pinion gear toward the ring gear side. A starter comprising a single or a plurality of drive springs, which are held between a plunger and the plunger shaft, and are set so that the spring force is increased stepwise in accordance with the increasing rate of the plunger attraction force of the magnet coil.