JP3550864B2 - Starter - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a starter for starting an engine, and more particularly to a ventilation structure for ventilating the inside and outside of the starter.
[0002]
[Prior art]
Normally, a starter for a vehicle is provided with a ventilation hole through which air flows in and out by respiration when a temperature difference occurs between the inside and the outside of the starter. However, in the engine room of vehicles in recent years, the mounting space has become dense due to the increase in accessories, the starter has been driven down below the engine, and the number of RV vehicles has increased the chance of running on waterways, etc. In many cases, the starter is exposed to a water flow such as strong water splashed by the rotation of the wheels. Therefore, in order to prevent inundation from the ventilation holes, a labyrinth structure (maze structure) is provided by providing a water impervious wall in the middle of the ventilation passage leading to the ventilation holes, or a ventilation pipe (rubber) Etc.) to increase the passage length.
In Japanese Utility Model Application Laid-Open No. 58-134062, a cover is provided outside the rear frame of the starter to form a closed space between the outer peripheral surface of the rear frame and the inner peripheral surface of the cover. A starter provided with a duct for communicating a closed space with the outside air has been proposed.
[0003]
[Problems to be solved by the invention]
However, in the case where only the ventilation hole is provided, when the starter receives the strong water flow as described above, water may flow backward from the ventilation hole and flood the inside of the starter.
On the other hand, ventilation pipes are attached to the frame of the starter, or ventilation ducts are provided by covering the frame itself with a cover. It is inefficient to set up ventilation pipes or ventilation ducts to correspond individually to the flow as the volume varies. Also, the ventilation pipes and ventilation ducts may not always be set at the optimum position due to other accessories and body parts, or extra parts may be attached to the outside of the machine frame to increase physique, so the starter itself However, there arises a problem that it cannot be mounted at a position originally required.
The present invention has been made on the basis of the above circumstances, and its purpose is to increase the outer space of the machine frame without infiltrating the functional components inside the starter even with a strong water flow applied to the starter. It is to provide a starter with excellent reliability.
[0004]
[Means for Solving the Problems]
According to the first aspect of the present invention, the first ventilation hole communicating the substantially annular ventilation passage formed along the inner peripheral surface of the yoke and the outside of the machine frame is opened at a position substantially in the ground direction of the machine frame. In addition, a second ventilation hole communicating the ventilation passage with the inside of the starting motor is opened at a position substantially in the ceiling direction of the passage forming member. Accordingly, even when a vehicle travels along a water path such as a puddle and a water current that causes wheels to jump is applied to the first ventilation hole, water that has entered the ventilation passage from the first ventilation hole is removed from the inner periphery of the yoke. Before arriving at the second ventilation hole which opens substantially in the ceiling direction through the inside of the ventilation passage formed in a substantially annular shape along the surface, it collides with the inner wall of the ventilation passage and its momentum is weakened. For this reason, the water that has entered from the first ventilation hole does not reach the second ventilation hole, does not enter the inside of the starting motor from the second ventilation hole, and does not flood into the functional components.
In addition, since a substantially annular ventilation passage is formed along the inner peripheral surface of the yoke, there is no component that extends outside the starter machine frame, and the degree of freedom in mounting on the engine is improved.
[0005]
According to the means of claim 2, a partition wall extending radially inward from one open end of the yoke (usually in a starter having a speed reduction mechanism, a partition wall separating the start motor and the speed reduction mechanism from each other) Is provided) as a part of the passage forming member. For this reason, a ventilation passage can be easily formed. Further, since the shape of the passage wall member constituting the passage forming member together with the partition wall can be simplified, the processing of the passage wall member is facilitated.
[0006]
According to the third aspect of the present invention, since the passage wall member integrally covers the inner periphery of the permanent magnet which is a field device, a holding member for holding the inner periphery of the permanent magnet is not required. Thus, the number of parts can be reduced.
[0007]
According to the fourth aspect of the invention, the passage wall member regulates the axial or circumferential movement of the permanent magnet, which is a field device, so that the permanent magnet can be positioned simultaneously with the formation of the ventilation passage.
[0008]
In the case where the partition is provided integrally with the yoke (that is, the partition is formed of the same material as the yoke), the magnetic flux does not leak due to the permanent magnet contacting the partition. In addition, it is necessary to provide a space between the partition and the permanent magnet. On the other hand, in the present invention, since the passage wall member constituting the passage forming member together with the partition wall is interposed between the partition wall and the permanent magnet and functions as a spacer therebetween, the permanent magnet is easily separated from the partition wall. it can.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a starter according to the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is an overall view of the starter.
The starter 1 according to the present embodiment includes a starter motor 2 that generates a rotational force, a planetary gear reduction mechanism (described later) that reduces the rotation of the starter motor 2, and the rotational force of the starter motor 2 is transmitted via the reduction mechanism. An output shaft (not shown), a pinion gear 4 that is provided movably on the output shaft in the front-rear direction (left-right direction in FIG. 1), meshes with the ring gear 3 of the engine, and drives the engine to rotate. An electromagnetic switch 5 for generating a force for pushing the pinion gear 4 toward the ring gear 3 (the left side in FIG. 1) via the motor, and controlling the energization of the starting motor 2, and a ventilation mechanism for ventilating the inside and outside of the starter 1. (To be described later).
[0010]
The starting motor 2 includes a yoke 6 constituting a yoke as a field device, a permanent magnet 7 which is a field pole fixed to the inner peripheral surface of the yoke 6, and receives a magnetic field of the field device when energized to rotate. Armature 8, a brush 10 slidably contacting an outer peripheral surface of a commutator 9 provided at an end of the armature 8, a brush holder 11 for holding the brush 10 slidably on the commutator 9, and the like. .
The yoke 6 has a cylindrical shape with both ends opened, and is provided with spigot portions 6a and 6b at both open ends. One spigot portion 6a fits with the spigot portion 12a of the center case 12, and the other spigot portion 6a. The portion 6b is fitted with the end frame 13. The center case 12, the yoke 6, and the end frame 13 are fastened to the housing 15 by through bolts 14.
[0011]
A plurality of permanent magnets 7 are fixed at equal intervals in the circumferential direction of the yoke 6. However, a fitting groove 7a is formed on the end surface of the permanent magnet 7 on the end frame 13 side, and the fitting groove 7a is fitted with a projection 6c which is partially projected on the inner periphery of the yoke 6. The positioning of the permanent magnet 7 in the circumferential direction with respect to the yoke 6 and the positioning in the axial direction toward the end frame 13 are performed.
The armature 8 is rotatably supported at both ends of the rotating shaft 8 a by bearings (not shown) fitted to the center case 12 and the end frame 13, respectively, and a starter switch (not shown) is turned on and built into the electromagnetic switch 5. The motor contacts (not shown) are closed to energize.
[0012]
The reduction mechanism includes a sun gear 16 formed on the outer periphery of the rotating shaft 8a, a plurality of planetary gears 17 meshing with the sun gear 16 and the external teeth, an internal gear 18 meshing with each planetary gear 17 and the internal teeth, and the like. The revolving force of each planet gear 17 is transmitted to an output shaft via a pin 19. The pin 19 rotatably supports the planet gear 17 via a bearing 20. This speed reduction mechanism is disposed inside the center case 12 and is separated from the inside of the yoke 6 by a partition 21. The partition 21 is provided separately from the yoke 6, and is sandwiched between the end face of the spigot portion 6 a of the yoke 6 and the step surface of the spigot portion 12 a of the center case 12.
[0013]
Both ends of the output shaft are rotatably supported by the housing 15 and the center case 12 via bearings (not shown), and are connected to a reduction gear via a one-way clutch (not shown). The one-way clutch connects the speed reduction mechanism and the output shaft when transmitting the rotational force of the starting motor 2 to the output shaft. When the pinion gear 4 meshes with the ring gear 3 and rotates at high speed by the engine, the one-way clutch rotates the pinion gear 4. Is separated from the output shaft and the speed reduction mechanism so that the power is not transmitted to the armature 8 of the starting motor 2.
The pinion gear 4 is fitted to the outer periphery of the output shaft via a helical spline, and is pushed forward (to the left in FIG. 1) on the output shaft along the helical spline to mesh with the ring gear 3 of the engine. be able to.
[0014]
When a built-in coil (not shown) is energized to generate a magnetic force, the electromagnetic switch 5 attracts a plunger (not shown) housed inside the switch, closes a motor contact, and drives a pinion transfer means. As a result, a pinion pushing force is generated. The electromagnetic switch 5 is provided with the speed reduction mechanism and the starting motor 2 with respect to the housing 15 and is coupled to an end of the housing 15 by screw means (a bolt 5b and a nut 5c formed on a case 5a of the electromagnetic switch 5). ing. The electromagnetic switch 5 is provided with a power supply terminal 22 to which a power supply line from a battery is connected and a motor terminal 24 to which a motor lead wire 23 which is a power supply line on the motor side is connected. When the plunger is pulled, the terminals 22 and 24 are electrically connected.
[0015]
The ventilation mechanism has a ventilation passage 25 formed annularly along the inner peripheral surface of the yoke 6, an external ventilation hole 26 communicating the ventilation passage 25 with the outside of the starter 1, and a ventilation passage 25 communicating with the inside of the starter 1. It comprises an internal ventilation hole 27.
The ventilation passage 25 includes a ventilation ring 28 (a passage wall member of the present invention) made of a non-magnetic material and disposed between the partition 21 and the permanent magnet 7 on the inner periphery of the yoke 6, and the ventilation ring 28 together with the ventilation ring 28. It is formed from the yoke 6 and the partition 21 forming one wall surface of the passage 25.
[0016]
The ventilation ring 28 is provided in an L-shaped cross section including a cylindrical portion 28a extending in the axial direction along the rotation shaft 8a and a flange portion 28b extending in the radial direction with respect to the rotation shaft 8a. It is arranged so as to abut on the motor-side end surface of the partition wall 21 over the entire circumference, and the end surface of the flange portion 28b abuts on the inner peripheral surface of the yoke 6 over the entire circumference. The inner peripheral surface of the ventilation ring 28 (the inner peripheral surface of the cylindrical portion 28a) is provided at substantially the same height (the distance from the center of rotation is substantially the same) as the inner peripheral surface of the permanent magnet 7.
The ventilation ring 28 has an overhang portion 28c in which a part of the flange portion 28b protrudes in the axial direction, and the overhang portion 28c is formed as shown in FIG. 2 (a plane viewed from the inside of the starting motor 2 to the outside ventilation hole 26). As shown in FIG. 1, the permanent magnets 7 are positioned between the permanent magnets 7 adjacent to each other in the circumferential direction so as to keep a constant interval between the permanent magnets 7 in the circumferential direction.
[0017]
The external ventilation hole 26 is formed by circumferentially overlapping a groove 6d provided in the spigot portion 6a of the yoke 6 and a groove 12b provided in the spigot portion 12a of the center case 12 (see FIG. 2). That is, the grooves 6d and 12b are formed at positions overlapping in the circumferential direction when assembled as the starter 1, and are positioned so as to be substantially directed to the ground when the starter 1 is mounted on the vehicle. ing. The ventilation passage 25 communicates with the outside of the machine frame (the yoke 6 and the center case 12) through the external ventilation hole 26.
The internal ventilation hole 27 is formed in the cylindrical portion 28 a of the ventilation ring 28 and communicates the ventilation passage 25 with the inside of the starting motor 2. However, the internal ventilation hole 27 is formed at a position substantially opposite to the external ventilation hole 26 in the circumferential direction of the ventilation passage 25, that is, at a position which is substantially in the top direction when the starter 1 is mounted on the vehicle.
[0018]
Next, the operation and effect of the present embodiment will be described.
Normally, even when the starter 1 operates to increase the internal temperature, or even when the starter 1 is stopped, the temperature around the starter 1 increases due to the heat generated by the engine being operated, and the starter 1 relatively increases. When an internal / external temperature difference occurs, the internal ventilation hole 27, the ventilation passage 25, and the external ventilation hole 26 perform a respiratory action.
Then, when the vehicle travels in a water channel such as a puddle and a water flow in which the wheels jumps up and falls near the external ventilation hole 26 provided substantially in the direction of the machine frame, water enters the ventilation passage 25 from the external ventilation hole 26. Will come. However, the water that has entered the ventilation passage 25 is formed in an annular shape before reaching the inside of the ventilation passage 25 from the external ventilation hole 26 opening substantially in the ground direction to the internal ventilation hole 27 opening substantially in the ceiling direction. The momentum collides with the inner wall of the ventilated passage 25, and its momentum is weakened. For this reason, the water that has entered the ventilation passage 25 from the external ventilation hole 26 does not reach the internal ventilation hole 27, and does not enter the inside of the starter motor 2 from the internal ventilation hole 27 and the functional components do not flood. .
[0019]
As described above, in this embodiment, the ventilation passage 25 is formed on the inner periphery of the yoke 6 over the entire periphery of the yoke 6 by effectively utilizing the space provided between the partition 21 and the permanent magnet 7. Thus, a sufficient passage length can be secured. For this reason, there are no parts that protrude outside the machine frame of the starter 1 and the degree of freedom in mounting on the engine is high, and even if a strong water flow applied to the starter 1 does not reach the inside of the starter motor 2, it is reliable. It is possible to provide a starter 1 having excellent properties.
In the present embodiment, the field device is the permanent magnet 7 and the positioning and the like are performed by the ventilation ring 28. However, it can be easily inferred that the same can be applied to a wound field device.
[0020]
(Second embodiment)
FIG. 3 is a sectional view of the inside of the starting motor 2 showing the ventilation mechanism, and FIG. 4 is a half sectional view of the field device.
This embodiment shows an example in which the cylindrical portion 28a of the ventilation ring 28 described in the first embodiment is extended in the axial direction, and the inner peripheral surface side of the permanent magnet 7 is held by the ventilation ring 28. is there.
[0021]
The ventilation ring 28 has a concave portion 28d depressed in the inner diameter direction in a part of the extended cylindrical portion 28a. The recess 28 d matches the outer shape of the inner periphery of the permanent magnet 7, and surrounds the permanent magnet 7 between the outer periphery of the recess 28 d and the inner periphery of the yoke 6. That is, since the concave portion 28d is provided, a step 28e is formed in the axial direction and the circumferential direction with respect to the cylindrical portion 28a forming the ventilation passage 25. Therefore, the step 28e and the flange 28b allow the plurality of permanent magnets 7 to be formed. Positioning can be performed. The ventilation ring 28 is provided with a concave portion 28f in which a part of the flange portion 28b is recessed toward the partition 21 in the axial direction between the permanent magnets 7 adjacent in the circumferential direction. The positioning of the ventilation ring 28 and the permanent magnet 7 with respect to the yoke 6 is performed by fitting into the projection 6c protruded on the inner circumference of the.
[0022]
According to the above configuration, the closed space of the ventilation passage 25 formed by the ventilation ring 28, the inner peripheral surface of the yoke 6, and the partition 21 is equal to the space formed between the permanent magnets 7 circumferentially adjacent to each other. Since it is larger than that of the first embodiment, this wide closed space acts as an air damper, and the effect of calming the momentum of the water flow entering from the external ventilation hole 26 is increased.
[0023]
(Third embodiment)
FIG. 5 is a sectional view of the inside of the starting motor 2 showing the ventilation mechanism.
This embodiment shows an example in which a so-called deep drawing yoke 6 with a bottom, in which the yoke 6 and the partition 21 shown in the first and second embodiments are integrally formed. However, the shape and the assembled state of the ventilation ring 28 are the same as in the first embodiment.
In such a bottomed yoke 6, since the bottom 6e (the portion corresponding to the partition 21) is formed of the same material as the yoke, in order to effectively reflect the magnetic flux of the permanent magnet 7 on the performance, the bottom 6e is formed on the bottom 6e. A spacer is inserted between the bottom 6 e and the permanent magnet 7 so that the magnetic flux does not leak due to the contact of the permanent magnet 7, or the end face of the permanent magnet 7 is brought into contact with the embossed portion provided on the yoke 6 so that the bottom 6 e and the permanent It is necessary to keep an interval with the magnet 7.
[0024]
On the other hand, in this embodiment, the ventilation ring 28 for forming the ventilation passage 25 is interposed between the bottom 6e of the yoke 6 and the permanent magnet 7 and functions as a spacer for separating the two, so that the exclusive spacer is used. And there is no need to provide an embossed portion on the yoke 6, and the same effects as in the first embodiment can be obtained. Therefore, a highly productive and highly reliable ventilation structure can be provided.
In the present embodiment, the magnet holding member 29 sandwiched between the yoke 6 and the end frame 13 is used, and the end surface of the permanent magnet 7 on the end frame 13 side is brought into contact with the magnet holding member 29. Is positioned in the axial direction on the end frame 13 side.
[0025]
(Fourth embodiment)
FIG. 6 is a sectional view of a ventilation ring 28 including an internal ventilation hole 27, and FIG. 7 is a sectional view of a ventilation ring 28 including an external ventilation hole 26.
In this embodiment, as shown in FIGS. 6 and 7, an example is shown in which a ventilation passage 25 is formed using a hollow ventilation ring 28 having a square cross section. However, the internal ventilation hole 27 is formed on the inner peripheral side wall surface of the ventilation ring 28 at a position which is substantially in the top direction when the starter is mounted on the vehicle, and the external ventilation hole 26 is substantially local when the starter is mounted on the vehicle. The groove 6d provided in the spigot portion 6a of the yoke 6, the groove 12b provided in the spigot portion 12a of the center case 12, and the communication port 30 opened in the outer peripheral side wall surface of the ventilation ring 28 are located at the opposite positions. It is formed by overlapping in the direction.
Also in this embodiment, since the annular ventilation passage 25 can be formed on the inner periphery of the yoke 6 over the entire periphery of the yoke 6 as in the first embodiment, the same effect as in the first embodiment is obtained. be able to.
[0026]
(Modification)
In the first and second embodiments, the positioning of the permanent magnets 7 is performed using the projections 6c formed by punching out the yoke 6, but the positions of the respective permanent magnets 7 are determined with a jig and bonded. May be employed. In this case, the projection 6c of the yoke 6 can be used as an aid for a jig for determining the position when the permanent magnet 7 is assembled.
In the third embodiment, the example in which the magnet pressing member 29 is used has been described. However, similarly to the first and second embodiments, the permanent magnet 7 is positioned by using the protrusion 6c of the yoke 6. Alternatively, as described above, the position of each permanent magnet 7 may be determined by a jig, and an assembly by bonding may be employed.
[0027]
In the first and second embodiments, the ventilation passage 25 is formed by the yoke 6, the partition 21, and the ventilation ring 28. It is also possible to use a passage forming member having a U-shaped cross section.
[Brief description of the drawings]
FIG. 1 is an overall view of a starter (first embodiment).
FIG. 2 is a plan view of an external ventilation hole viewed from the inside of a starting motor (first embodiment).
FIG. 3 is a sectional view of the inside of a starting motor showing a ventilation mechanism (second embodiment).
FIG. 4 is a half sectional view of a field device (second embodiment).
FIG. 5 is a sectional view of the inside of a starting motor showing a ventilation mechanism (third embodiment).
FIG. 6 is a sectional view of a ventilation ring including an internal ventilation hole (fourth embodiment).
FIG. 7 is a sectional view of a ventilation ring including an external ventilation hole (fourth embodiment).
[Explanation of symbols]
1 Starter 2 Starting motor 6 Yoke (machine frame)
6e Bottom of yoke (part corresponding to partition)
7. Permanent magnet (magnet field device)
12 Center case (machine frame)
21 Partition wall (passage forming member)
25 Ventilation passage 26 External ventilation hole (first ventilation hole)
27 Internal ventilation holes (second ventilation holes)
28 Ventilation ring (passage wall member / passage forming member)

Claims (5)

A yoke of a starting motor, which constitutes a part of the machine frame and has a field device inside thereof,
A passage forming member that forms a substantially annular ventilation passage along the inner peripheral surface of the yoke;
A first ventilation hole that opens at a position substantially in the ground direction of the machine frame when the engine is mounted and communicates the ventilation passage with the outside of the machine frame;
A starter having a second ventilation hole which is opened at a position substantially in the ceiling direction of the passage forming member when the engine is mounted and communicates the ventilation passage with the inside of the starting motor. The passage forming member includes a partition wall extending radially inward from one opening end of the yoke, and a passage wall member forming the ventilation passage with the inner surfaces of the partition wall and the yoke each as one wall surface. 2. The starter according to claim 1, wherein the second ventilation hole is formed at a position substantially in the top direction of the passage wall member. The field device is a field device using a permanent magnet,
The starter according to claim 1, wherein the passage wall member integrally covers an inner circumference of the permanent magnet. The starter according to any one of claims 1 to 3, wherein the passage wall member restricts movement of the permanent magnet in an axial direction or a circumferential direction. The starter according to claim 2, wherein the partition is provided integrally with the yoke.

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