JPH10231769A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit poor slide of a pinion gear and poor operation of a rotation control member by reducing slurry, dust, etc., entering the inner part of a starter accompanying with the rotation of a ring gear. SOLUTION: The outer periphery of a cylindrical part 33 integrally formed with a pinion gear 5 at the rear part of the pinion gear 5 is provided with a plurality of tooth parts 33a. Where, the outside of each tooth part 33a is set to smaller than that of the pinion gear 5. The pinion gear 5 receives rotation control by engaging one end 7a of a rotation control member 7 with each tooth part 33a before current carrying is applied to a starting motor 2 by mean of an electromagnetic switch 6. A front case 8 for housing the pinion gear 5 in the front case has a narrow gap at the outer periphery of the pinion gear 5 and an inner peripheral face 8b facing the outer peripheral face of the pinion gear 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter for starting an engine.

[0002]

2. Description of the Related Art As a prior art, Japanese Patent Application Laid-Open No. 8-144906 is known.
There is a starter described in Japanese Unexamined Patent Application Publication No. H11-163,873. This starter
A pinion gear fitted with a helical spline on the outer circumference of the output shaft, and a rotation restricting member for restricting rotation of the pinion gear are provided.When the rotation of the armature is started, the rotation restricting member is operated by the attraction force of the electromagnetic switch to rotate the pinion gear. By regulating, the pinion gear is axially moved by the thrust generated in the helical spline and meshes with the ring gear of the engine. According to this meshing method, the pinion gear can be pushed out in the axial direction by the attraction force of the electromagnetic switch and the attraction force of the electromagnetic switch can be reduced as compared with the method in which the pinion gear meshes with the ring gear, which is effective in reducing the size and weight of the electromagnetic switch. Was. Also, since the miniaturized electromagnetic switch can be placed behind the starting motor,
This has greatly contributed to the downsizing of the entire starter and the improvement in mountability.

[0003]

However, since the front case of the starter is provided with an opening through which the pinion gear advances and bites into the ring gear,
When the pinion gear bites into the ring gear and starts the engine, a large amount of muddy water, dust, etc., which has entered the clutch housing of the engine is swept up by the rotation of the ring gear and penetrates into the starter through the opening of the front case. As a result, mud or dust entering the inside of the starter accumulates on the helical spline formed on the output shaft or on a movable portion of the device that regulates the rotation of the pinion moving body, resulting in poor sliding or rotation of the pinion moving body. This may cause a malfunction of the regulating device, and may deteriorate the engagement between the pinion gear and the ring gear. The present invention has been made based on the above circumstances, and an object of the present invention is to reduce slippage and rotation of a pinion moving body by reducing muddy water and dust entering a front case with rotation of a ring gear. An object of the present invention is to provide a starter capable of suppressing a malfunction of a regulating device.

[0004]

According to the first aspect of the present invention, the front case has an inner peripheral surface opposed to the outer peripheral surface of the pinion gear with a small gap on the outer periphery of the pinion gear. Thus, when the pinion gear meshes with the ring gear to drive the ring gear, the path area through which muddy water, dust, and the like, which have been scraped up by the rotation of the ring gear, enter the inside of the starter can be minimized. As a result, poor sliding of the pinion moving body due to accumulation of mud and dust and poor operation of the rotation restricting member can be suppressed.

According to the second aspect of the present invention, the pinion moving body is formed such that the outer diameter of the uneven portion is smaller than the outer diameter of the pinion gear. As a result, even if the pinion moving body advances on the output shaft by a predetermined distance (to a position where the pinion gear completely meshes with the ring gear), the uneven portion does not hit the inner peripheral surface of the front case. Can be formed close to the outer periphery of the pinion gear.

According to the third aspect of the present invention, the pinion moving body has a flange formed with an uneven portion axially rearward of the pinion gear, and a gap formed between the flange and the pinion gear. A cylindrical portion having an outer diameter smaller than the diameter is provided. In this case, when the pinion moving body moves forward, the air around the cylindrical portion is pushed by the axial front end surface of the flange portion and moves to generate an airflow. Since this airflow flows in the moving direction of the pinion moving body, an effect of suppressing intrusion of mud, dust, and the like from the gap between the pinion gear and the inner peripheral surface of the front case is produced. In addition, there is also an effect of blowing out mud, dust, and the like slightly entering the inside of the starter to the outside of the starter by an air current.

[0007]

Next, a starter according to the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a sectional view of a starter 1. The starter 1 of this embodiment has a machine frame (described later) that forms a substantially cylindrical outer shape, and a start motor 2 that generates a rotational force inside the machine frame, and a rotation of the start motor 2. A planetary gear speed reducer (to be described later) for reducing the speed of the motor, an output shaft 3 that rotates upon receiving the rotation output of the speed reducer, a pinion gear 5 that moves on the output shaft 3 and meshes with a ring gear 4 of the engine, and a starting motor 2. An electromagnetic switch 6 for controlling energization,
A rotation restricting member 7 for restricting the rotation of the pinion gear 5 before the starting motor 2 starts is housed.

The machine frame includes a front case 8, a center case 9, a yoke 10, a brush holder 11, and a rear case 1.
2 and is entirely fixed by tightening through bolts (not shown). The front case 8 has a mounting surface 8a orthogonal to the output shaft 3, and is fixed to a side wall (clutch housing / not shown) of the engine via the mounting surface 8a. As shown in FIG. 2, the front case 8 has an inner peripheral surface 8b opposed to the outer peripheral surface of the pinion gear 5 with a small gap on the outer periphery of the pinion gear 5, and a lower portion of the inner peripheral surface 8b. On the side, an opening 8c for the pinion gear 5 to mesh with the ring gear 4 is provided.

The starting motor 2 has a fixed magnetic pole 13 (for example, a plurality of permanent magnets) fixed to an inner peripheral surface of a yoke 10 which also serves as a part of a machine frame and a magnetic frame. An armature 14 is rotatably arranged, and a brush 16 is arranged on a commutator 15 provided at an end of the armature 14. One end of the yoke 10 is spigot-fitted with the opening end of the center case 9, and the other end is spigot-fitted with the opening end of the brush holder 11. The armature 14 is rotatably supported via a bearing 18 in which one end of a rotating shaft 17 is inserted into a recess 3a formed at the rear end of the output shaft 3 and fitted on the inner peripheral surface of the recess 3a. The other end is rotatably supported via a bearing 19 held by the brush holder 11.

The commutator 15 is formed by combining a plurality of insulated commutator pieces 15a on the outer periphery of the other end of the rotating shaft 17 in a cylindrical shape. The brush 16 has a commutator 15
Of the brush holder 11 and the plate 2
0 in the brush storage chamber 21 formed by the spring 2
2 and is urged by the spring 22 against the outer peripheral surface of the commutator 15. However, the brush 16
The brush storage chamber 21 is slidably arranged in the radial direction (the vertical direction in FIG. 1), and is restricted from moving in the rotational direction.

The reduction gear includes a sun gear 23 (external teeth) formed on the outer periphery of one end of the rotating shaft 17, an internal gear 24 (internal teeth) arranged on a radially outer periphery of the sun gear 23,
It comprises a plurality of planetary gears 25 arranged between the sun gear 23 and the internal gear 24 and meshing with both gears 23, 24. The internal gear 24 is formed on a gear component 24 </ b> A arranged on the inner periphery of the center case 9. The gear constituent member 24A is provided in the inner cylindrical portion 9a of the center case 9.
And a roller 26 housed between the inner cylindrical portion 9a and the gear component member 24A to form a one-way clutch. And armature 1
4 so as to be rotatable in the anti-rotational direction. The planet gear 25 has a pin 27 press-fitted into a large-diameter portion 3b provided on the outer periphery of the rear end of the output shaft 3, and is rotatably supported via a bearing 28 fitted on the outer periphery of the pin 27.

The output shaft 3 is disposed coaxially with the rotary shaft 17, and has one end rotatably supported via a bearing 29 held by the front case 8, and the other end mounted on the inner cylindrical portion 9 a of the center case 9. It is rotatably supported via a held bearing 30 and is restricted from moving in the axial direction with respect to the center case 9. Also, ahead of the center case 9 (left direction in FIG. 1).
A helical spline 3c (see FIG. 2) is provided on a part of the outer peripheral surface of the output shaft 3 protruding from the shaft.

The pinion gear 5 is provided with a helical spline 5a (see FIG. 2) on the inner peripheral surface. The helical spline 5a is fitted on the helical spline 3c of the output shaft 3 so as to be movable on the output shaft 3. And the pinion gear 5
Is urged rearward (to the right in FIG. 1) of the starter 1 by a return spring 31 disposed in front of the starter 1. The return spring 31 includes a collar 32 fixed to the outer periphery of the output shaft 3 in front of the pinion gear 5 and a pinion gear 5.
And the front end face of the

As shown in FIG. 2, a cylindrical portion 33 extending rearward from the pinion gear 5 is formed integrally with the pinion gear 5, and a plurality of teeth 33a are formed on the outer periphery of the cylindrical portion 33.
Is provided. However, the outer diameter D1 of the tooth portion 33a
Is set smaller than the outer diameter D2 of the pinion gear 5. A disk-shaped washer 34 is rotatably supported on a rear end surface of the cylindrical portion 33 via a bearing 35. The washer 34 has an outer diameter substantially equal to (or slightly smaller than) the root diameter of the tooth portion 33a.
Note that the pinion moving body of the present invention includes the pinion gear 5 and the cylindrical portion 33.

The electromagnetic switch 6 is disposed behind the brush holder 11 and is housed in a rear case 12 provided in a bowl shape. The electromagnetic switch 6 includes a cylindrical frame 36 having an opening in the center of the bottom surface, and a ground plate 3 fixed by caulking to an opening end of the frame 36.
7, a suction coil 38 housed in the frame 36, a plunger 39 which is arranged to be able to move up and down the inner periphery of the suction coil 38 through an opening of the frame 36, etc., with the movement of the plunger 39. The motor contacts (described below) interposed in the energizing circuit (see FIG. 3) of the starting motor 2 are opened and closed.

The frame 36, the ground plate 37, and the plunger 39 are provided by magnetic materials, respectively, and constitute a magnetic circuit of the electromagnetic switch 6. The plunger 39 faces the ground plate 37 via an air gap at the inner periphery of the suction coil 38, and acts between the ground plate 37 and the plunger 39 when the suction coil 38 is energized and a magnetic flux flows through the magnetic circuit. The magnetic force is applied to the ground plate 37 (upward in FIG. 1).

As shown in FIG. 3, the motor contacts include a battery-side fixed contact 40, a motor-side fixed contact 41, and a movable contact 42. The battery-side fixed contact 40 is connected to the cable 4
Battery terminal 45 connected to battery 44 through 3
And the movable contact 4 inside the rear case 12.
2 are arranged opposite to each other. A screw portion for screwing a nut (not shown) around the outer periphery of the battery terminal 45 is fixed to the rear case 12 by a washer 46 with the screw portion protruding from the rear case 12.
The motor-side fixed contact 41 is electrically connected to the brush 16 on the positive electrode side through a lead wire 47, and is disposed inside the rear case 12 so as to face the movable contact 42.

The movable contact 42 is attached to an end of a rod 48 provided integrally with the plunger 39 via an insulating member 49, moves together with the plunger 39, and contacts the fixed contacts 40 and 41 (electrical contact). ) To close the motor contact, and separate from the fixed contacts 40 and 41 to open the motor contact. When the movable contact 42 comes into contact with the fixed contacts 40 and 41, the movable contact 42 is urged by the contact spring 50 via the insulating member 49, so that a required contact pressure is applied to the fixed contacts 40 and 41. Can be abutted. The rod 48 protrudes upward from the center of the upper end surface of the plunger 39, through a through-hole (not shown) formed in the center of the ground plate 37.
The contact spring 50 is disposed on the outer periphery of the rod 48, one end of the contact spring 50 is locked by the insulating member 49, and the other end is
8 is engaged with a step surface provided on the outer periphery of the base member 8.

The rotation restricting member 7 is formed, for example, by winding a metal rod into a coil shape and bending both ends 7a and 7b of the rod in the same direction at substantially right angles. The rotation restricting member 7 is disposed in a flat space formed between the end face of the center case 9 and the plate 51 fixed to the front side of the center case 9, with the portion wound in a coil shape being disposed in a flat space.
1 is movably provided in the vertical direction in FIG. 1 and is always urged upward by a spring 52 fixed to the plate 51 (see FIG. 2). The rotation restricting member 7 is connected to the plunger 39 of the electromagnetic switch 6 via a connecting member 53 such as a wire, and the plunger attraction (movement of the plunger 39) of the electromagnetic switch 6 is transmitted through the connecting member 53. Then, it moves downward in FIG. 1 against the urging force of the spring 52, and when the attraction force of the electromagnetic switch 6 disappears, it returns to the initial position (the position shown in FIG. 1) by the urging force of the spring 52.

Both ends 7a, 7b bent at right angles
Are taken out of the plate 51 through openings (not shown) provided in the plate 51, respectively. One end 7a is located radially above the output shaft 3 and outside the toothed portion 33a, and the other end 7b is connected to the output shaft 3
Is located rearward of a washer 34 arranged on the rear end face of the cylindrical portion 33 on the lower side in the radial direction. In addition, one end 7a
When the starter 1 is in a stationary state (non-operating state), the length that overlaps the tooth portion 33a of the cylindrical portion 33 in the axial direction is L.
1. When the axial length of the tooth portion 33a is L2, the following relationship is established (see FIG. 2). L1 ≤ L2

However, one end 7a is connected to the pinion gear 5
Even if the motor moves forward on the output shaft 3 by a predetermined distance (for example, the end surface of the pinion gear 5 has moved to a position where it comes into contact with the end surface of the ring gear 4), the rotation regulating member 7 receives the attractive force of the electromagnetic switch 6 and moves downward. When moved, the teeth 3 of the cylindrical portion 33
3a. When the radial distance between one end 7a and the outer peripheral surface of the tooth portion 33a is L3, and the distance between the movable contact 42 of the electromagnetic switch 6 and the fixed contacts 40 and 41 is L4, the following relationship is obtained. (See FIG. 1). L3.ltoreq.L4 This allows one end 7a to engage with the tooth 33a before the electromagnetic switch 6 energizes the starting motor 2 (before the movable contact 42 contacts the fixed contacts 40 and 41). It is possible. However, if the above-mentioned relationship (L3.ltoreq.L4) is satisfied, the radial position of one end 7a (outermost diameter D3 of the rotation restricting member 7) may be outside or inside the outer diameter D2 of the pinion gear 5.

Next, the operation of this embodiment will be described. When the key switch 54 (see FIG. 3) is closed, a current flows from the battery 44 to the attraction coil 38 of the electromagnetic switch 6 to generate a magnetic force, and the plunger 39 is attracted upward in FIG. The movement of the plunger 39 pulls the other end 7b of the rotation restricting member 7 downward through the connecting member 53, so that the entire rotation restricting member 7 moves downward in FIG. As a result, one end 7 a of the rotation restricting member 7 engages with the teeth 33 a provided on the outer periphery of the cylindrical portion 33 to restrict the rotation of the pinion gear 5.

On the other hand, the electromagnetic switch 6 has a plunger 39
The movable contact 42 abuts on both fixed contacts 40 and 41 by the movement of
4 flows, and the armature 14 starts rotating. When the motor contacts are closed, the pinion gear 5 is already closed.
Rotation is regulated. The rotation of the armature 14 is transmitted to the output shaft 3 after being decelerated by the reduction gear, and is transmitted to the output shaft 3.
Rotates. The rotation of the output shaft 3 also causes the pinion gear 5 to rotate. However, since the rotation of the pinion gear 5 is restricted as described above, the rotation of the output shaft 3 is controlled by the mesh between the helical spline 3c and the helical spline 5a. Acts as thrust. As a result, the pinion gear 5 advances on the output shaft 3 and meshes with the ring gear 4, so that the torque of the starting motor 2 is transmitted from the pinion gear 5 to the ring gear 4 to start the engine.

When the pinion gear 5 meshes with the ring gear 4, one end 7 a of the rotation restricting member 7 is disengaged from the teeth 33 a of the cylindrical portion 33, and is located behind the washer 34 disposed on the rear end surface of the cylindrical portion 33. By entering, the pinion gear 5 is restricted from retreating. After starting the engine, key switch 5
4, the current to the attraction coil 38 is cut off, and the force for attracting the plunger 39 is lost.
Is pushed back in FIG. 1 by the urging force of the spring 52 and returns to the initial position. As a result, one end 7a of the rotation restricting member 7, which has previously restricted the retraction of the pinion gear 5, comes off the washer 34, so that the pinion gear 5
Retraction restrictions are released. As a result, the pinion gear 5 separates from the ring gear 4, retreats on the output shaft 3, and is pushed back to the rest position (the position shown in FIG. 1). Further, as the rotation regulating member 7 moves upward in FIG. 1, the plunger 39 is pulled downward and moved through the connecting member 53, so that the movable contact 42 separates from the fixed contacts 40 and 41 and the motor contact 42 Is opened, the power supply to the armature 14 is cut off, and the rotation of the armature 14 is stopped.

(Effect of this embodiment) In this embodiment, the outer diameter D1 of the cylindrical portion 33 (outer diameter of the tooth portion 33a) formed integrally with the pinion gear 5 is set smaller than the outer diameter D2 of the pinion gear 5. As a result, the inner peripheral surface 8b of the front case 8
Can be made closer to the outer periphery of the pinion gear 5 to reduce the gap with the pinion gear 5. Thus, when the pinion gear 5 meshes with the ring gear 4 to drive the ring gear 4, it is possible to minimize the path area in which the muddy water, dust, and the like scraped up by the ring gear 4 enter the inside of the starter 1. As a result, poor sliding of the pinion gear 5 and poor operation of the rotation restricting member 7 due to accumulation of mud and dust can be suppressed. In this embodiment, the pinion gear 5
And the cylindrical portion 33 are formed integrally, but may be formed separately. However, in this case, it is necessary to restrict the rotation so that the pinion gear 5 and the cylindrical portion 33 cannot rotate relative to each other.

(Second Embodiment) FIG. 4 is an enlarged sectional view around the pinion gear. The pinion moving body according to the present embodiment includes the pinion gear 5, a cylindrical portion 55 extending rearward from the pinion gear 5, and a flange portion 56 radially expanding from the rear end of the cylindrical portion 55. A tooth portion 56a is provided on the outer periphery. However, the outer diameter D5 of the cylindrical portion 55 is set smaller than the outer diameter D2 of the pinion gear 5 and smaller than the root diameter D6 of the tooth portion 56a. In addition, the collar 56
Axial front end face 56b and inner wall face 8d of front case 8
An axial distance S from the inner peripheral surface 8b (a wall surface formed substantially at right angles from the rear end of the inner peripheral surface 8b) is set to be larger than a moving distance in which the pinion moving body moves in the axial direction.

According to the configuration of the present embodiment, when the pinion moving body moves forward, air around the cylindrical portion 55 is pushed by the axial front end surface 56b of the flange portion 56 and moves to generate an airflow. This air flow is generated in the moving direction of the pinion moving body (FIG. 4).
To the left), the effect of suppressing intrusion of mud, dust, and the like from the gap between the pinion gear 5 and the inner peripheral surface 8b of the front case 8 is produced. Also, there is an effect that the mud, dust, or the like slightly entering the inside of the starter 1 is blown out of the starter 1 by an air current. In this embodiment, the axial distance S between the flange portion 56 and the inner wall surface 8d of the front case 8 is set.
Is larger than the moving distance of the pinion moving body,
Is the outer diameter D of the pinion gear 5 (the outer diameter of the tooth portion 56a).
Even if it is larger than 2, the flange portion 56 does not hit the inner wall surface 8d of the front case 8 when the pinion moving body advances on the output shaft 3 by a predetermined distance. Therefore, if the outer diameter of the flange 56 (the outer diameter of the tooth portion 56a) is set to be smaller than (or substantially equal to) the outer diameter D2 of the pinion gear 5, the axial length of the cylindrical portion 55 can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a starter (first embodiment).

FIG. 2 is a sectional view around a pinion gear (first embodiment).

FIG. 3 is an electric circuit diagram of a starting motor.

FIG. 4 is a sectional view around a pinion gear (second embodiment).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Starter 2 Starter motor 3 Output shaft 3c Helical spline of output shaft 4 Ring gear 5 Pinion gear (pinion moving body) 5a Helical spline of pinion gear 7 Rotation restricting member 8 Front case 8b Inner peripheral surface 8c Opening 33 Cylindrical part (pinion moving body) / 1st Example) 33a Tooth portion (irregular portion) 55 Cylindrical portion (pinion moving body / second example) 56 Flange portion (pinion moving member / second example) 56a Tooth portion (irregular portion)

Claims (3)

[Claims] 1. A start motor for generating a rotational force, an output shaft rotatably driven by the start motor, a concavo-convex portion on an outer periphery, and a pinion gear meshing with a ring gear of an engine in an axial front of the concavo-convex portion. A pinion moving body fitted on the output shaft via a helical spline, and a rotation restricting member that restricts rotation of the pinion moving body by engaging with the uneven portion before the starting motor is energized. A starter, which accommodates the pinion moving body therein and has a front case provided with an opening for the pinion gear to mesh with the ring gear, wherein the front case has a slight gap around the outer periphery of the pinion gear. A starter having an inner peripheral surface facing an outer peripheral surface of the pinion gear. 2. The starter according to claim 1, wherein the pinion moving body is formed such that an outer diameter of the uneven portion is smaller than an outer diameter of the pinion gear. 3. The pinion moving body has a flange formed with the uneven portion axially rearward of the pinion gear, and a gap between the flange and the pinion gear, the outer diameter of the concave portion of the uneven portion. The starter according to claim 1, wherein a cylindrical portion having a small outer diameter is provided.