JPH10231768A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a starter capable of preventing a rear case made of a resin from deformation or damage caused by fastening a through bolt. SOLUTION: A rear case 9 for covering a starter 1 at its rear end is made of a resin. Its inner peripheral side is provided with a padding part 9a for passing a through bolt 15. The padding part 9a extends toward the axial front from the rear end wall of the rear case 9. Its axial end face and the opening end face of the rear case 9 are formed on the same plane. An annular metal plate 14 being interjacent between the rear case 9 and the yoke 10 of a starting motor 2 has two round holes for passing the through bolt 15 at the radial facing position. The metal plate 14 is provided with its outside diameter having the same dimension as those of the rear case 9 and the yoke 10. The radial width of the annular part is formed with slightly larger than the radial dimension containing the padding part 9a of the rear case 9.

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 In recent years, demands for reducing the weight of vehicles have been increasing in order to improve fuel efficiency, and starters are no exception. For example, in a starter described in Japanese Patent Application Laid-Open No. Sho 60-208071, the rear case, which has been made of a metal such as an iron plate or aluminum, is made of resin to reduce the weight.

[0003]

However, in the starter described in the above publication, FIGS. 9 and 10 (C in FIG. 9) are used.
As shown in FIG. 1C, a cladding portion 130 having an insertion hole 120 for passing the through bolt 110 is provided on the outer peripheral portion of the rear case 100.
A through bolt 110 inserted through 20 is disposed radially outside the yoke 140 (see FIG. 9). That is, the yoke 140 does not have a contact surface that comes into contact with the end face of the overlay 130 in the axial direction. Therefore, the contact surface of the rear case 100 that actually contacts the end surface of the yoke 140 is
Only the inner peripheral side is included, and the end face of the built-up portion 130 is not included, so that the area receiving the tightening force of the through bolt 110 does not increase. In addition, the portion (the contact surface between the yoke 140 and the rear case 100) that receives the fastening force of the through bolt 110 is only a part of the through bolt 110 in the circumferential direction. As a result, when the rear case 100 is made of resin, the rear case 100 may be deformed or damaged unless the tightening force of the through bolt 110 is strictly controlled.

In order to prevent deformation and breakage of the rear case 100, it is conceivable to increase the thickness of the rear case 100 as a whole. However, in this case, the physical size increases and the weight increases. The advantage of weight reduction, which is an advantage of a metal rear case, is reduced by half. The present invention has been made based on the above circumstances, and an object of the present invention is to provide a starter capable of preventing deformation and breakage of a resin rear case due to tightening of through bolts.

[0005]

According to the present invention, a bolt insertion portion is provided in a rear case made of resin so as to surround the outer periphery of the through bolt at least half a circumference and pass the through bolt in the axial direction. The metal member adjacent to the rear case has a contact surface that comes into contact with the axial front end surface of the bolt insertion portion. As a result, the area receiving the through-bolt tightening force is larger than before, and the portion that receives the through-bolt tightening force is formed so as to surround at least half of the outer circumference of the through bolt,
Deformation or breakage of the resin rear case can be prevented without strictly controlling the tightening force of the through bolt.

The metal member includes an annular metal plate sandwiched between the yoke of the starting motor and the rear case, and the metal plate and the bolt insertion portion. And a metal cylindrical member interposed therebetween. In this case, the cylindrical member may or may not be fixed to the metal plate or the rear case. Further, as the metal member, the yoke of the starting motor described in claim 4, the front case described in claim 5, the brush holder described in claim 6, and the like can be used. However,
When using the front case as a metal member,
This is possible by extending the bolt insertion portion of the rear case forward in the axial direction and bringing the front end surface in the axial direction into contact with the rear end surface in the axial direction of the front case.

[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 according to the present embodiment includes a starting motor 2 that generates a rotational force,
A one-way clutch 4 movably provided on a rotating shaft 3 of the starting motor 2, a pinion gear 5 to which the rotating force of the starting motor 2 is transmitted through the one-way clutch 4, and an electromagnetic switch 6 for controlling the energization of the starting motor 2. A lever 7 for moving the one-way clutch 4 in the axial direction by receiving the attraction force of the electromagnetic switch 6, a front case 8 covering the front side of the starter 1, a rear case 9 covering the rear side of the starter 1, and the like. .

The starting motor 2 comprises a yoke 10, a fixed field 1
1, an armature 12, a brush 13, and the like. The yoke 10 forms a part of a magnetic circuit, and is provided in a cylindrical shape with a magnetic material (for example, made of iron).
4, is sandwiched between the front case 8 and the rear case 9 and is fixed by tightening through bolts 15. For the fixed field 11, a plurality of permanent magnets are used,
Each is fixed to the inner peripheral surface of the yoke 10 while keeping a slight gap with the outer peripheral surface of the armature 12. Instead of the permanent magnet, the fixed field 11 may be configured by fixing a pole core on the inner peripheral surface of the yoke 10, and winding a field coil around the outer periphery of the pole core.

The armature 12 includes the rotating shaft 3, an armature core 16 fixed to the outer periphery of the rotating shaft 3 and forming a part of a magnetic circuit, and an armature coil 17 provided on the armature core 16. And a commutator 18 and the like electrically and mechanically coupled to the armature coil 17. The rotation axis 3 is
Bearing 19 having one end fixed to the front end of front case 8
, And the other end is rotatably supported by a bearing 20 fixed to the rear case 9. The commutator 18 is provided on the outer circumference of one end side (the right side in FIG. 1) of the rotating shaft 3, and a sliding contact surface with the brush 13 is formed in a cylindrical shape.

The brush 13 is arranged on the outer periphery of the commutator 18, is slidably held in the radial direction by a brush holder 21, and is constantly pressed against the outer peripheral surface of the commutator 18 by a spring 22. The brush 13 on the positive electrode side is mechanically and electrically connected to a motor terminal 23 provided in the electromagnetic switch 6 through a lead wire 13a, and the brush 13 on the negative electrode side is grounded through a lead wire (not shown). ing. The brush holder 21 is fixed to the rear case 9 by screws or the like (not shown).

The one-way clutch 4 has a well-known structure, is fitted on the outer periphery of the rotating shaft 3 via a helical spline (not shown), and is movable on the three rotating shafts along the helical spline. Is provided. The pinion gear 5 is rotatably fitted to the outer periphery of the rotary shaft 3 in front of the one-way clutch 4 via a bearing (not shown), and is provided movably on the rotary shaft 3 integrally with the one-way clutch 4. ing. The pinion gear 5 advances on the rotating shaft 3 integrally with the one-way clutch 4 and meshes with the ring gear 24 of the engine, and transmits the torque of the starting motor 2 transmitted through the one-way clutch 4 to the ring gear 24. The forward position of the pinion gear 5 is regulated by abutting on a collar 25 fixed on the rotating shaft 3.

The electromagnetic switch 6 is arranged radially outside the starting motor 2 and is fixed to the front case 8 by bolts or the like (not shown). The electromagnetic switch 6 includes a coil (not shown) that generates a magnetic force when energized, and a plunger 26 slidably disposed on the inner periphery of the coil. The motor contacts interposed in the energizing circuit of the starting motor 2 are opened and closed.

The motor contacts include a motor-side fixed contact (not shown) formed integrally with the motor terminal 23, a battery-side fixed contact (not shown) formed integrally with the battery terminal 27, and the plunger 26. When the movable contact moves together with the plunger 26 and comes into contact with (electrically contacts) both fixed contacts, a battery (not shown) mounted on the vehicle starts the motor 2. When the movable contact is separated from the fixed contacts, the current supply to the starting motor 2 is cut off. The battery terminal 27 and the motor terminal 23 are provided so as to protrude from the rear end face of the electromagnetic switch 6 to the outside, and are connected to the battery through a cable (not shown).

The lever 7 has an upper end connected to a joint 28 provided on the plunger 26 and a lower end connected to the one-way clutch 4 so that the lever 7 can swing about a fulcrum 29 provided on the front case 8. Is provided. Accordingly, when the plunger 26 is attracted (moves rightward in FIG. 1) by receiving the magnetic force of the coil, the upper end of the lever 7 connected to the joint 28 with the fulcrum 29 as the center is rearward (see FIG. 1). Right), and the lower end moves forward. As a result, the one-way clutch 4 connected to the lower end is pushed forward along the helical spline on the rotating shaft 3 integrally with the pinion gear 5. When the magnetic force of the coil disappears and the plunger 26 is pushed back to the original position (moves to the left in FIG. 1), the upper end connected to the joint 28 moves forward with the fulcrum 29 as the center, and the lower end moves. The part moves backward. As a result, the one-way clutch 4 connected to the lower end retreats along the helical spline on the rotating shaft 3 integrally with the pinion gear 5.

The front case 8 is formed of a metal such as aluminum to be a member to be attached to the engine. The rear case 9 is resin-molded to reduce the weight. As the resin material, for example, a thermosetting resin such as a phenol resin is used. In this rear case 9,
As shown in FIG. 2, a built-up portion 9a that expands toward the inner peripheral side of the rear case 9 is provided integrally, and an insertion hole 9b for passing a through bolt 15 is provided substantially in the center of the built-up portion 9a in the axial direction. It is formed through. The build-up portion 9a extends axially forward from the rear end wall of the rear case 9 so that its axial end surface 9c is flush with the opening end surface 9d of the rear case 9 (see FIG. 2). In addition, the overlay 9a is
It is not always necessary to surround the entire circumference of the through bolt 15, but it is sufficient that at least half the circumference is covered. Further, as shown in FIG. 3, a notch 9e or the like may be formed in the overlay portion 9a.

The metal plate 14 is interposed between the yoke 10 of the starting motor 2 and the rear case 9, and is formed into an annular press as shown in FIG. A round hole 14a for passing the through-bolt 15 is formed at a location. This metal plate 14 has an outer diameter of the rear case 9.
And the yoke 10 have the same dimensions, and the radial width A (see FIG. 4) of the annular portion is equal to the build-up portion 9a of the rear case 9.
Are slightly larger than the radial dimension B (see FIG. 2). Therefore, the metal plate 14 has an area capable of contacting not only with the opening end face 9d of the rear case 9 but also with the axial end face 9c of the overlay 9a.

A plurality of projections 14b and 14c are formed on both sides of the metal plate 14 by pressing or the like. The one protrusion 14b protruding from the yoke 10 side can be positioned in the radial direction with the yoke 10 by entering the inner peripheral surface of the yoke 10 (see FIG. 1). Rear case 9
The other protrusion 14 c protruding from the side can enter the inner peripheral surface of the rear case 9 to perform positioning with respect to the rear case 9 in the radial direction. The axial end faces of the rear case 9 and the yoke 10 that are in contact with the metal plate 14 are flat surfaces. The through bolt 15 is inserted from the rear end face 9 f of the rear case 9 into the insertion hole 9 b of the overlay 9 a and the round hole 14 a of the metal plate 14, and the inner periphery of the yoke 10 (the fixed field 11 adjacent to each other in the circumferential direction). ) Is fastened to the screw portion 8a provided on the front case 8.

Next, the operation of this embodiment will be described. When a key switch (not shown) is closed and current flows through the coil of the electromagnetic switch 6, the plunger 26 is attracted by the magnetic force generated by the coil. As a result, the one-way clutch 4 and the pinion gear 5 are pushed forward on the rotary shaft 3 integrally through the lever 7, and the front end face of the pinion gear 5 comes into contact with the end face of the ring gear 24 and stops. On the other hand, plunger 2
When the movable contact comes into contact with both fixed contacts with the movement of 6,
A current flows from the battery to the starting motor 2 to rotate the armature 12, and the rotation is transmitted to the pinion gear 5 via the one-way clutch 4. Thus, when the pinion gear 5 rotates to a position where it can mesh with the ring gear 24 and meshes with the ring gear 24, the rotation of the pinion gear 5 is transmitted to the ring gear 24 and the engine is started.

When the key switch is opened after starting the engine,
Since the current to the coil is cut off and the force for attracting the plunger 26 (the magnetic force of the coil) disappears, the plunger 26 that has been attracted until then is reacted by a spring (not shown) provided in the electromagnetic switch 6. Is pushed back to the original position. When the movable contact moves away from both fixed contacts with the movement of the plunger 26, the current to the starting motor 2 is cut off and the rotation of the armature 12 stops. Further, since the movement of the plunger 26 is transmitted to the one-way clutch 4 through the lever 7, the engagement between the pinion gear 5 and the ring gear 24 is released, and the one-way clutch 4 and the pinion gear 5 are disengaged.
Together move back on the rotating shaft 3 and return to the rest position (the position shown in FIG. 1).

(Effect of this embodiment) In this embodiment, a metal plate 14 is interposed between the rear case 9 and the yoke 10, and the end face in the axial direction of the cladding 9a of the rear case 9 is brought into contact with the metal plate 14. In this state, the through bolt 15 can be tightened. As a result, the area for receiving the tightening force of the through bolt 15 is increased by the amount of the overlaid portion 9a, and the portion receiving the tightening force of the through bolt 15 is formed such that the outer periphery of the through bolt 15 becomes cylindrical (or at least a half circumference or more) ) Since it is formed so as to surround, deformation or breakage of the resin rear case 9 due to the tightening of the through bolts 15 can be prevented without strictly controlling the tightening force of the through bolts 15.

(Second Embodiment) FIG. 5 is a rear sectional view of the starter 1. As shown in FIG. In this embodiment, the through bolt 15 is
1 shows an example disposed on the outer periphery of the. in this case,
As shown in FIG. 5, the overlay portion 9 a of the rear case 9 is provided so as to protrude radially outward of the rear case 9. Also,
The metal plate 14 is formed so as to protrude outward in the radial direction only at a portion corresponding to the build-up portion 9a and to be in contact with the axial end surface of the build-up portion 9a.

(Third Embodiment) FIG. 6 is a rear sectional view of the starter 1. As shown in FIG. This embodiment shows another example in which the through bolt 15 is disposed on the outer periphery of the yoke 10, as in the second embodiment. In this embodiment, the overlay 9a of the rear case 9 is provided.
6 has a reduced length in the axial direction (length in the left-right direction in FIG. 6), and a metal cylindrical member having a through-hole 30a formed between the overlay 9a and the metal plate 14 to allow the through bolt 15 to pass therethrough. 30 is interposed. In this case, the through bolt 1 is held in a state in which the axial end surface of the overlay 9a is in contact with the end surface of the cylindrical member 30.
5, the first embodiment and the second embodiment can be tightened.
The same effect as that of the embodiment can be obtained. The cylindrical member 30 may or may not be fixed to the metal plate 14 or the rear case 9. Further, the cylindrical member 30 may be formed integrally with the metal plate 14.

(Fourth Embodiment) FIG. 7 is a rear sectional view of the starter 1. As shown in FIG. This embodiment shows an example in which the overlay 9a of the rear case 9 is extended forward (toward the front case 8). As shown in FIG. 7, the cladding portion 9a of the rear case 9 extends toward the front case 8 through the outer periphery of the yoke 10, and the axial end face 9c of the cladding portion 9a is
Is in contact with the opening end face 8b of the opening. The opening end face 8b of the front case 8 has an area corresponding to the axial end face 9c of the built-up part 9a because the screw part 8a for screwing the through bolt 15 is formed. Accordingly, the entire area of the axial end face 9c of the cladding portion 9a can be reduced without interposing a separate member such as the metal plate 14 between the opening end face 8b of the front case 8 and the cladding portion 9a of the rear case 9. It can be received at the opening end face 8b of the case 8.

(Fifth Embodiment) FIG. 8 is a rear sectional view of the starter 1. As shown in FIG. This embodiment shows an example in which the metal plate 14 (see the drawings of each embodiment) shown in the first to third embodiments is also used as one component of the brush holder 21. Since the brush holder 21 is arranged close to the metal plate 14 shown in the first to third embodiments, by making the brush holder 21 made of metal, one component of the brush holder 21 is made of a metal plate. 14 can be used. In this case, since the brush holder 21 is sandwiched between the yoke 10 and the rear case 9, it is not necessary to fix the brush holder 21 to the rear case 9 with screws or the like.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a built-up portion of a rear case (first embodiment).
Example).

FIG. 3 is a perspective view showing a built-up portion of the rear case (first embodiment).
Example).

FIG. 4 is a perspective view of a metal plate (first embodiment).

FIG. 5 is a rear sectional view of a starter (second embodiment).

FIG. 6 is a rear sectional view of a starter (third embodiment).

FIG. 7 is a rear sectional view of a starter (fourth embodiment).

FIG. 8 is a rear sectional view of a starter (fifth embodiment).

FIG. 9 is a rear sectional view of a starter (prior art).

FIG. 10 is a sectional view taken along line CC of FIG. 9 (prior art).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Starter 2 Starter motor 8 Front case 9 Rear case 9a Overlay part (bolt insertion part) 10 Yoke 13 Brush 14 Metal plate (metal member / annular metal plate) 15 Through bolt 18 Commutator 21 Brush holder 30 Cylindrical Element

Claims (6)

[Claims] 1. A resin-made rear case which covers an axial rear end portion adjacent to a metal member, and a through bolt which presses and fixes the rear case to the metal member in an axial direction. A starter, wherein the rear case is provided with a bolt insertion portion that surrounds the outer periphery of the through bolt at least a half or more and passes the through bolt in the axial direction, and the metal member includes an axial direction of the bolt insertion portion. A starter having a contact surface that contacts an axial front end surface. 2. The starter according to claim 1, wherein the metal member is sandwiched between a yoke forming a magnetic frame of a starting motor and the rear case. 3. The metal member comprises: an annular metal plate sandwiched between a yoke forming a magnetic frame of a starting motor and the rear case; and a metal member between the metal plate and the bolt insertion portion. 2. A starter according to claim 1, wherein said starter comprises a metal cylindrical member interposed between said starters. 4. The starter according to claim 1, wherein said metal member is a yoke forming a magnetic frame of a starting motor. 5. The rear case, wherein the bolt insertion portion extends axially forward through the outer periphery of a yoke forming a magnetic frame of a starting motor, and has an axial front end face to which the through bolt is fastened. The starter according to claim 1, wherein the starter is in contact with an axial rear end surface of a metal front case. 6. The starter according to claim 1, wherein said metal member is a brush holder for holding a brush that slides on a commutator of a starting motor.