JP4174829B2 - Starter - Google Patents

Description

  One end is helically splined to the inner circumference of the tube, the other end is equipped with an output shaft that is supported by being inserted through the bearing, and the pinion gear is arranged at the end of the output shaft that protrudes outward from the bearing. The present invention relates to a starter having a cantilever support structure.

2. Description of the Related Art Conventionally, a starter having a so-called cantilever support structure in which a pinion gear is disposed outside a bearing that supports an output shaft is known (see, for example, Patent Document 1).
FIG. The starter shown in FIG. 3 includes a drive shaft that is rotated by transmission of the driving force of the motor, and a substantially cylindrical output shaft that is helically splined to the outer periphery of the drive shaft and supported by a housing via a bearing. A pinion gear is provided at the end of the output shaft that protrudes from the bearing to the outside of the housing.

  However, in the starter of the above (Patent Document 1), there is only one bearing that supports the output shaft, and when the output shaft protrudes to the engine side with respect to the drive shaft, the overhang amount of the output shaft protruding from the bearing is small. Since it increases, the output shaft tends to tilt. As a result, when the pinion gear meshes with the ring gear and cranks the engine, the output shaft rotates with the bearing as a fulcrum, so an excessive load acts on the bearing, leading to a decrease in the life of the bearing and an output. There was a possibility that abnormal noise would be generated by rotating the shaft in an inclined state.

On the other hand, the present applicant has a substantially cylindrical tube that rotates when the rotational force of the motor is transmitted, and an output shaft that is helically splined to the inner periphery of the tube, and is disposed at the end of the output shaft. When a pinion gear to be engaged with a ring gear is proposed, a starter that moves the output shaft in the axial direction via an engagement member fixed to the output shaft has been proposed.
In this starter, the tube is formed long in the axial direction, the outer periphery of one end side of the tube is supported by the first bearing with respect to the center housing, and the outer periphery of the other end side of the tube is supported by the second bearing with respect to the starter housing. By doing so, the distance (bearing span) between both bearings can be taken long.

As a result, even when the output shaft jumps out to the engine side to the position where the pinion gear meshes with the ring gear, the bearing span is larger (longer) than the overhang amount of the output shaft (the amount protruding from the second bearing to the engine side). Therefore, even when the pinion gear meshes with the ring gear and cranks the engine (when a large load is applied to the output shaft), the inclination of the output shaft can be prevented. As a result, it is possible to suppress a decrease in the life of the bearing and to prevent or reduce the occurrence of abnormal noise.
US Patent Application Publication No. 2003/0097891 (FIG. 3)

  However, in the starter of the prior application proposed by the applicant, the tube is formed long in the axial direction, and the other end of the tube is supported by the second bearing with respect to the starter housing. In other words, since the tube covers the outside of the output shaft inside the starter housing, it is necessary to devise for disposing the engaging member fixed to the output shaft on the outside of the tube. On the other hand, in the starter of the prior application, a pin is inserted into the hole formed in the output shaft and fixed, and a long groove for passing the pin through the tube is formed in order to take the pin out of the tube. The engaging member is fixed to a pin that is taken out to the outside of the tube.

In the above configuration, since the outer diameter of the engaging member is inevitably increased due to the arrangement of the engaging member on the outer side of the tube, the outer diameter of the starter housing covering the outer side of the engaging member is increased. It was necessary and there was a risk of being restricted by the engine installation.
In addition, there is a problem that the weight increases due to a long tube formation or an increase in the outer diameter of the engaging member.

  Furthermore, the long groove formed in the tube moves while rotating along the helical spline torsion angle when the output shaft moves in the axial direction with respect to the tube. It cannot be a simple straight line shape, and it is necessary to form it obliquely so as to be substantially equal to the twist angle of the helical spline, which is difficult to process.

  Further, since the engaging member cannot be directly fixed to the output shaft, not only a pin for connecting the output shaft and the engaging member is required, but also processing for fixing the pin to the output shaft (output shaft) A process for making a hole for inserting the pin into the pin) is required, and it is also necessary to fix the engaging member to the pin by some method. As described above, the structure is complicated, and the processing for realizing the structure is also complicated, which increases the manufacturing cost.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a starter having a so-called cantilever support structure in which a pinion gear is disposed outside a bearing that supports the output shaft (an end portion of the output shaft protruding from the bearing). Therefore, it is an object of the present invention to provide a starter that can reduce the number of parts and reduce the weight by simplifying the structure by enabling the housing to have a smaller diameter.

(Invention of Claim 1)
The present invention has a tube having a substantially cylindrical shape that rotates by transmitting the rotational force of the motor, one end side of the output shaft is helically spline-coupled to the inner periphery of the tube, and the other end side of the output shaft protruding from the tube is A so-called pinion gear is disposed at the end of the output shaft that is inserted in a first bearing fixed to the housing and is rotatably and slidably supported and projects outward from the first bearing (on the opposite side of the tube). It is a starter with a cantilever support structure.
The tube has a substantially cylindrical inner periphery on one end side supported by a bearing portion provided on the rotation shaft of the motor via a second bearing so that the outer periphery on the other end side of the substantially cylindrical shape is a housing or The structure supported by the housing is rotatably supported via a third bearing.

  According to said structure, the axial direction both ends of a tube are supported by the housing in the stable state via the 2nd bearing and the 3rd bearing. Further, the output shaft is helically splined at one end to the inner periphery of the tube and the other end is supported by the housing via the first bearing, so that both ends of the output shaft are supported in a stable state. . As a result, even when the pinion gear meshes with the ring gear and cranks the engine, the tilt of the output shaft can be suppressed, so the load on the bearing (especially the first bearing) can be reduced and the life due to early wear of the bearing Reduction can be suppressed.

Further, the starter according to claim 1 has an output shaft moving means for moving the output shaft to the engine side in order to mesh the pinion gear with the ring gear, and the output shaft moving means protrudes in the counter-motor direction from the tube. An engagement member fixed to the output shaft and drive means for applying a force for pushing the output shaft in the axial direction via the engagement member are provided.
In this configuration, it is not necessary to dispose the engaging member outside the tube, and the engaging member can be directly fixed to the output shaft. Therefore, the engaging member can be reduced in diameter compared with the starter of the prior application described above. It is possible to reduce the outer diameter of the housing that houses the combined member.

Moreover, the weight of the starter can be reduced by shortening the axial length of the tube and reducing the outer diameter of the engaging member.
Further, since the engaging member can be directly fixed to the output shaft, there is no need to form a long groove (long groove along the helical torsion angle of the helical spline) in the tube, and the output shaft and the engaging member are connected via the pin. There is no need to concatenate. As a result, the number of parts can be reduced and the structure can be simplified when compared with the starter of the prior application, so that the parts can be easily assembled and the cost can be reduced.
The clutch for intermittently transmitting power between the motor and the tube has a clutch outer that is driven directly or indirectly by the motor and rotates, and a clutch inner that is rotated by power transmitted from the clutch outer. This clutch inner is formed as a part of the tube.
According to this configuration, the length in the axial direction of the tube includes the amount of the clutch inner, and accordingly, one end of the output shaft supported by the tube by helical spline coupling and the housing via the first bearing. It is possible to lengthen the distance between the other end of the supported output shaft (referred to here as the shaft support span) and the pinion gear meshes with the ring gear, so the overhang when the output shaft jumps out to the engine side. The shaft support span can be increased relative to the amount. As a result, the stress generated in the output shaft during engine cranking can be reduced, and a starter having a stable cantilever support structure can be provided. Further, the output shaft can be reduced in diameter and weight by reducing the stress of the output shaft.
Further, the clutch has an outer plate that is provided integrally with the clutch outer, and a driven gear or a straight spline is formed inside a hollow hole that opens in a radial central portion of the outer plate. However, the clutch outer is directly driven by the motor by meshing with a drive gear or a straight spline formed on the rotating shaft of the motor. According to the above configuration, the clutch outer is directly centered on the rotation shaft of the motor, and the clutch inner (tube) is also centered on the rotation shaft of the motor via the second bearing, thereby preventing the eccentricity of the clutch. And stable clutch performance can be secured.

The present invention has a tube having a substantially cylindrical shape that rotates by transmitting the rotational force of the motor, one end side of the output shaft is helically spline-coupled to the inner periphery of the tube, and the other end side of the output shaft protruding from the tube is A so-called pinion gear is disposed at the end of the output shaft that is inserted in a first bearing fixed to the housing and is rotatably and slidably supported and projects outward from the first bearing (on the opposite side of the tube). It is a starter with a cantilever support structure.
The tube has a substantially cylindrical inner periphery on one end side supported by a bearing portion provided on the rotation shaft of the motor via a second bearing so that the outer periphery on the other end side of the substantially cylindrical shape is a housing or The structure supported by the housing is rotatably supported via a third bearing.
According to said structure, the axial direction both ends of a tube are supported by the housing in the stable state via the 2nd bearing and the 3rd bearing. Further, the output shaft is helically splined at one end to the inner periphery of the tube and the other end is supported by the housing via the first bearing, so that both ends of the output shaft are supported in a stable state. . As a result, even when the pinion gear meshes with the ring gear and cranks the engine, the tilt of the output shaft can be suppressed, so the load on the bearing (especially the first bearing) can be reduced and the life due to early wear of the bearing Reduction can be suppressed.
The starter according to claim 2 has an output shaft moving means for moving the output shaft to the engine side in order to mesh the pinion gear with the ring gear, and the output shaft moving means protrudes in the counter-motor direction from the tube. An engagement member fixed to the output shaft and drive means for applying a force for pushing the output shaft in the axial direction via the engagement member are provided.
In this configuration, it is not necessary to dispose the engaging member outside the tube, and the engaging member can be directly fixed to the output shaft. Therefore, the engaging member can be reduced in diameter compared with the starter of the prior application described above. It is possible to reduce the outer diameter of the housing that houses the combined member.
Moreover, the weight of the starter can be reduced by shortening the axial length of the tube and reducing the outer diameter of the engaging member.
Further, since the engaging member can be directly fixed to the output shaft, there is no need to form a long groove (long groove along the helical torsion angle of the helical spline) in the tube, and the output shaft and the engaging member are connected via the pin. There is no need to concatenate. As a result, the number of parts can be reduced and the structure can be simplified when compared with the starter of the prior application, so that the parts can be easily assembled and the cost can be reduced.
The second bearing is characterized by being press-fitted into the inner periphery of the tube.
According to this configuration, when assembling each component of the starter, after the output shaft is inserted into the inner periphery of the tube, the second bearing is assembled to the inner periphery on one end side of the tube. Since it functions as a stopper for the output shaft, assembly is improved. The second bearing may be a rolling bearing such as a ball bearing or a roller bearing, or a sliding bearing such as a plain bearing.
The clutch for intermittently transmitting power between the motor and the tube has a clutch outer that is driven directly or indirectly by the motor and rotates, and a clutch inner that is rotated by power transmitted from the clutch outer. This clutch inner is formed as a part of the tube.
According to this configuration, the length in the axial direction of the tube includes the amount of the clutch inner, and accordingly, one end of the output shaft supported by the tube by helical spline coupling and the housing via the first bearing. It is possible to lengthen the distance between the other end of the supported output shaft (referred to here as the shaft support span) and the pinion gear meshes with the ring gear, so the overhang when the output shaft jumps out to the engine side. The shaft support span can be increased relative to the amount. As a result, the stress generated in the output shaft during engine cranking can be reduced, and a starter having a stable cantilever support structure can be provided. Further, the output shaft can be reduced in diameter and weight by reducing the stress of the output shaft.
Further, the clutch has an outer plate that is provided integrally with the clutch outer, and a driven gear or a straight spline is formed inside a hollow hole that opens in a radial central portion of the outer plate. However, the clutch outer is directly driven by the motor by meshing with a drive gear or a straight spline formed on the rotating shaft of the motor. According to the above configuration, the clutch outer is directly centered on the rotation shaft of the motor, and the clutch inner (tube) is also centered on the rotation shaft of the motor via the second bearing, thereby preventing the eccentricity of the clutch. And stable clutch performance can be secured.

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

FIG. 1 is a cross-sectional view of the starter 1, and FIG. 4 is an electric circuit diagram of the starter 1.
The starter 1 of this embodiment includes a motor 2 that generates a rotational force, a substantially cylindrical tube 3 through which the rotational force of the motor 2 is transmitted via a speed reducer and a clutch (both will be described later), and the tube The output shaft 4 provided so as to be movable in the axial direction on the inner periphery of the output shaft 4, the pinion gear 5 assembled to the end of the output shaft 4, and the output shaft 4 for meshing the pinion gear 5 with the ring gear 6 of the engine Output shaft moving means (to be described later) or the like for moving the engine to the engine side (left side in FIG. 1).

  The motor 2 includes a field 7 that generates magnetic flux (a magnetic field is shown in FIG. 1, but a wound field may be used), an armature 8 having a commutator, and a brush that is in sliding contact with the commutator. 9 (see FIG. 4) and the like. In this motor 2, a yoke 10 that forms a magnetic circuit as a field 7 also serves as a machine frame of the motor 2, and is sandwiched between a front housing 11 and an end frame 12 and fixed by tightening through bolts (not shown). Has been.

The reduction gear is a known planetary gear mechanism having a plurality of planetary gears 15 meshing with a sun gear 13 formed on a rotating shaft (hereinafter referred to as an armature shaft 8a) of a motor 2 and an internal gear 14 having internal teeth. The rotational speed of the armature 8 is reduced to the revolution speed of the planetary gear 15.
The clutch is formed as a part of the tube 3 and a clutch outer 17 to which the revolving motion (motor rotation after deceleration) of the planetary gear 15 is transmitted via a gear shaft 16 that rotatably supports the planetary gear 15. The clutch inner 18 is constituted by a clutch roller 19 disposed between the clutch outer 17 and the clutch inner 18, and the torque is transmitted from the clutch outer 17 to the clutch inner 18 (tube 3) via the clutch roller 19. This is a one-way clutch that cuts off torque transmission from the clutch inner 18 to the clutch outer 17.

  The clutch outer 17 is integrally provided with a carrier portion 20 that supports the gear shaft 16 of the planetary gear 15, and a circular fitting hole is formed at the radial center of the carrier portion 20. The tube 3 is fitted on the outer periphery. The gear shaft 16 to be supported may be provided integrally with the carrier portion 20, but is formed separately from the carrier portion 20 and fixed to the carrier portion 20 (for example, press-fitted and fixed in a hole formed in the carrier portion 20). You may do it.

  As shown in FIG. 2, the tube 3 has a female helical spline 3a formed on the inner periphery of a substantially cylindrical shape, and an inner periphery (female) on one axial end side (right side in FIG. 2) where the female helical spline 3a is formed. The inner periphery of the helical spline 3a is supported so as to be relatively rotatable with respect to a bearing portion 8b provided on the armature shaft 8a of the motor 2 via a bearing 21 (second bearing of the present invention). The outer periphery on the end side is rotatably supported via a bearing 23 with respect to a center case 22 (structure of the present invention) fixed to the front housing 11.

  The tube 3 is formed such that the outer diameter of the outer peripheral surface supported by the bearing 23 is slightly smaller than the outer diameter of the outer peripheral surface used as the clutch inner 18, and a step is provided between the outer peripheral surfaces. By this step and the fixing member 24 (washer or retaining ring) fixed to the outer peripheral surface of the tube 3 adjacent to the other end side end surface (end surface on the opposite clutch side) of the bearing 23, This prevents axial movement. The female helical spline 3a formed on the inner periphery of the tube 3 is formed from one end of the tube 3 to the middle of the other end, and the end of the female helical spline 3a when the output shaft 4 moves to the engine side. It is provided as a stopper 3b for stopping the movement of.

  As shown in FIG. 3, the bearing 21 that supports the inner periphery of the tube 3 is a ball bearing in which an inner ring 21a and an outer ring 21b are provided so as to be relatively rotatable via balls 21c (rolling elements). A gap is fitted to the outer periphery of a bearing portion 8b provided on the armature shaft 8a, and the outer ring 21b is press-fitted and fixed to the inner periphery of the tube 3 (the inner periphery of the female helical spline 3a). In addition to the ball bearing, it is possible to employ a roller bearing that uses a roller as a rolling element.

  As shown in FIG. 2, the output shaft 4 has a large-diameter portion having a slightly larger outer diameter on one end side in the axial direction, and a male helical spline 4a is formed on the outer periphery of the large-diameter portion. A male helical spline 4 a is meshed with a female helical spline 3 a formed on the inner periphery of the tube 3. Further, the other end side (small diameter portion) having a smaller diameter than the large diameter portion protrudes from the end surface of the tube 3 and extends in the counter-motor direction (left direction in FIG. 1) as shown in FIG. The bearing 25 fixed to the end portion is inserted through the inside of the bearing 25 and is supported so as to be rotatable and slidable. A seal member 26 that prevents foreign matter from entering the sliding gap between the bearing 25 and the output shaft 4 is disposed outside the bearing 25 (left side in FIG. 1).

When the output shaft 4 moves to the engine side with respect to the tube 3, the output shaft 4 stops at a position where the end of the male helical spline 4 a comes into contact with the terminal end (stopper 3 b) of the female helical spline 3 a. A return spring 27 that generates elasticity for pushing back the output shaft 4 moved to the engine side between the outer periphery of the output shaft 4 (small diameter portion) inserted inside the tube 3 and the inner periphery of the tube 3. (See FIG. 2) is arranged.
One end of the return spring 27 is supported by a step portion 4 b (spring receiving portion of the present invention) between a large diameter portion and a small diameter portion provided on the outer periphery of the output shaft 4. It is supported by a spring receiving portion 3c provided inside the end side end portion.

The pinion gear 5 is spline-coupled to the end of the output shaft 4 projecting outward from the bearing 25 (engine side), and is rotatably supported integrally with the output shaft 4.
The output shaft moving means can be engaged with the engagement member 28 crossing the rotation direction of the engagement member 28 (the rotation direction of the output shaft 4), and the ring-shaped engagement member 28 fixed to the output shaft 4. A rotation restriction rod 29 and an electromagnetic switch 31 that drives the rotation restriction rod 29 via a connecting bar 30.

  The engagement member 28 is press-fitted to the outer periphery of the output shaft 4 (small diameter portion) protruding from the end surface on the side opposite to the clutch of the tube 3 (the left end surface in FIG. 1), and axially and circumferentially with respect to the output shaft 4. It is fixed. Further, on the outer periphery of the engaging member 28, an uneven portion 28 a that can engage with the rotation restricting rod 29 is provided continuously in the circumferential direction. The method of fixing the engagement member 28 to the output shaft 4 is not limited to press-fitting, and any method other than press-fitting (for example, knurling) can be used as long as it can be fixed to the output shaft 4 in the axial direction and the circumferential direction. Fitting).

  Needless to say, the fixing position of the engaging member 28 with respect to the output shaft 4 is the inner side in the axial direction (on the opposite side of the engine) from the bearing 25 that supports the output shaft 4, and the starter 1 is stationary (the state shown in FIG. 1). In addition, the engagement member 28 is in a position where it contacts (contacts) the end face on the side opposite to the clutch of the tube 3. That is, the engagement member 28 contacts the end face on the side opposite to the clutch of the tube 3 when the output shaft 4 moved to the engine side returns to the stationary position shown in FIG. 4 has a function as a stopper capable of stopping 4 at a stationary position.

  The rotation restricting rod 29 is provided integrally with an arm portion 32 (see FIG. 1) that receives the electromagnetic force of the electromagnetic switch 31 via the connecting bar 30. As a specific example, a rod-shaped spring material is formed in a ring shape, and both ends of the spring material are bent at substantially right angles in the same direction from a position substantially opposite to the radial direction of the ring shape, The part is provided as a rotation restricting rod 29, and the other end is provided as an arm part 32.

  As shown in FIG. 1, the rotation restricting rod 29 is disposed with a slight gap on the outer side in the radial direction of the engaging member 28, and receives the electromagnetic force of the electromagnetic switch 31 to press the arm portion 32 downward in the drawing. Then, the arm portion 32 is pushed down integrally with the arm portion 32 and engaged with the concavo-convex portion 28 a of the engaging member 28 to restrict the rotation of the engaging member 28. Further, when the electromagnetic force of the electromagnetic switch 31 disappears, it is separated from the concavo-convex portion 28a of the engaging member 28 by a reaction force of a spring (not shown) and returns to the position shown in FIG.

The connecting bar 30 transmits the electromagnetic force of the electromagnetic switch 31 to the arm portion 32. For example, both ends of a metal rod-shaped material are bent at a predetermined angle and provided in a substantially crank shape, and one end side is a plunger of the electromagnetic switch 31. 33 (see FIG. 4) via a hook 34 (see FIG. 1), and the other end is directly engaged with the arm portion 32.
The electromagnetic switch 31 is used as the output shaft moving means described above and performs an opening / closing operation of contact means (main contact A and sub contact B) provided in the energization circuit of the motor 2 shown in FIG. 35 (see FIG. 4), the plunger 33, a return spring (not shown), and the like, and as shown in FIG. The end frame 12 covers it.

The exciting coil 35 is energized from the battery 37 and generates magnetic force when the start switch 36 (ignition switch) shown in FIG. 4 is closed.
The plunger 33 is inserted inside the exciting coil 35, and when the exciting coil 35 is energized to generate a magnetic force, it is attracted to a magnetized fixed iron core (not shown) and moved upward in FIG. The sub contact B and the main contact A are closed.
The return spring opens the main contact A and the sub contact B by pushing back the plunger 33 when the energization to the exciting coil 35 is stopped and the magnetic force disappears.

The main contact A is connected to the first fixed contact 39 connected to the positive electrode of the battery 37 via the terminal bolt 38, and to the positive brush 9 (see FIG. 4) connected to the positive electrode side via the brush lead wire 9a. The first movable contact 40 is insulated and held by a contact holder 41 connected to the plunger 33 and moves integrally with the plunger 33 so as to face the first fixed contact 39. .
As shown in FIG. 1, the terminal bolt 38 is attached through the end frame 12, and a first fixed contact 39 is integrally provided on the inside of the end frame 12, and is taken out to the outside of the end frame 12. A battery cable 42 (see FIG. 4) is connected to the male screw portion.

The sub-contact B is provided integrally with the second fixed contact 43 provided in electrical connection with the first fixed contact 39 and the first movable contact 40, and faces the second fixed contact 43. And a second movable contact 44 that is movable.
The second fixed contact 43 is formed using a material (for example, carbon material) having a larger electric resistance than the first fixed contact 39, and is fixed to the terminal bolt 38 via a metal plate (not shown), for example. ing.
The second movable contact 44 is formed of, for example, a metal plate that is bent into a U shape and has elasticity.

  Note that the main contact A and the sub contact B are connected to the sub contact B before the main contact A in order to suppress the rotation speed of the armature 8 when the motor 2 is started (until the pinion gear 5 is engaged with the ring gear 6). Is configured to close. Specifically, as shown in FIG. 4, the second fixed contact 43 forming the sub-contact B is determined from the distance between the first fixed contact 39 forming the main contact A and the first movable contact 40. And the distance between the contact points of the second movable contact 44 are set smaller.

Next, the operation of the starter 1 will be described.
When the start switch 36 is closed, the exciting coil 35 of the electromagnetic switch 31 is energized to generate a magnetic force, and the plunger 33 is attracted by the magnetic force and moves upward in FIG. When the movement of the plunger 33 is transmitted to the arm portion 32 via the connecting bar 30, the rotation restricting rod 29 moves downward in FIG. 1 integrally with the arm portion 32, and moves to the uneven portion 28 a of the engaging member 28. By engaging, the rotation of the output shaft 4 is regulated together with the engaging member 28.

When the sub contact B is closed before the main contact A with the movement of the plunger 33, the electric resistance of the second fixed contact 43 is large, so that the starting current flowing from the battery 37 to the armature 8 is reduced, The armature 8 rotates at a low speed. When the rotation of the armature 8 is further decelerated by the reduction gear and is transmitted to the tube 3 via the clutch, the tube 3 rotates slowly.
Here, even if the tube 3 rotates, since the output shaft 4 is restricted from rotating, the rotational force of the tube 3 is converted into a thrust force (forward force) by the action of the helical spline and applied to the output shaft 4, As a result, the output shaft 4 moves to the engine side.

  When the pinion gear 5 disposed on the output shaft 4 meshes smoothly with the ring gear 6 due to the movement of the output shaft 4, the rotation restricting rod 29 is disengaged from the concavo-convex portion 28 a of the engaging member 28 and the rear of the engaging member 28. The rotation restriction of the output shaft 4 is released by entering the side (tube 3 side). Further, the tip of the rotation restricting rod 29 supports the rear side surface of the engaging member 28, so that the output shaft 4 is prevented from moving backward. It should be noted that a thrust bearing (not shown) may be assembled on the rear side of the engaging member 28 (the part where the tip of the rotation restricting rod 29 abuts), and the tip of the rotation restricting rod 29 may be brought into contact with this thrust bearing. . In this case, since the rotation of the engaging member 28 can be absorbed by the thrust bearing with respect to the rotation restricting rod 29, the deformation of the rotation restricting rod 29 can be prevented.

  On the other hand, if the side surfaces of both the gears 5 and 6 collide without the pinion gear 5 smoothly meshing with the ring gear 6, the movement of the output shaft 4 is temporarily stopped at that time, so that the rotational force of the tube 3 is changed to the thrust force. It acts in the direction of rotating the output shaft 4 without being converted. At this time, the rotation of the output shaft 4 is restricted by the rotation restricting rod 29. However, since the rotation restricting rod 29 formed of a spring material has elasticity, the rotation restricting rod 29 is provided with the uneven portion 28a of the engaging member 28. A slight rotation (for example, rotation of one tooth of the pinion gear 5) is allowed while being engaged. Accordingly, when the output shaft 4 rotates to a position where the pinion gear 5 can mesh with the ring gear 6, the output shaft 4 moves forward again by receiving the thrust force, so that the pinion gear 5 can mesh with the ring gear 6.

  Thereafter, when the main contact A is closed, a large current flows through the main contact A having a lower electrical resistance than the sub contact B, so that the armature 8 rotates at a high speed. After the high-speed rotation of the armature 8 is decelerated by the reduction gear, it is transmitted to the tube 3 through the clutch, and the output shaft 4 rotates at a high speed integrally with the tube 3, so that the ring gear 6 meshing with the pinion gear 5 is obtained. The torque is transmitted and cranks the engine.

  When the start switch 36 is opened after the engine is started, the energization to the exciting coil 35 is cut off and the magnetic force disappears, so that the plunger 33 is pushed back by the reaction force of the return spring. As the plunger 33 moves, the force acting on the arm portion 32 via the connecting bar 30 (the force that pushes the rotation restricting rod 29 downward in FIG. 1) is released. The restriction rod 29 is pushed back upward in FIG. As a result, the rotation restricting rod 29 is pulled out from the rear side of the engaging member 28, so that the backward restriction of the output shaft 4 is released, and the output shaft 4 is pushed back to the anti-engine side by the reaction force of the return spring 27. The joining member 28 comes into contact with the end face of the tube 3 and stops at the stationary position.

(Effect of Example 1)
According to the starter 1 described above, the inner periphery (the inner periphery of the female helical spline 3 a) on one end side in the axial direction of the tube 3 is interposed via the bearing 21 with respect to the bearing portion 8 b provided on the armature shaft 8 a of the motor 2. The outer periphery on the other end side in the axial direction is rotatably supported with respect to the center case 22 via a bearing 23. In addition, since the output shaft 4 is helically splined at one end to the inner periphery of the tube 3 and the other end is supported by the end of the front housing 11 via the bearing 25, the both ends of the output shaft 4 are in a stable state. Will be supported. As a result, even when the pinion gear 5 meshes with the ring gear 6 and cranks the engine, the inclination of the output shaft 4 can be suppressed, so the load on the bearing (particularly the bearing 25) can be reduced and the bearing 25 can be worn out quickly. It is possible to suppress a decrease in life due to.

  Further, since the clutch inner 18 is formed as a part of the tube 3 (the axial length of the tube 3 includes the amount of the clutch inner 18), the output shaft 4 supported by the tube 3 by helical spline coupling is used. It is possible to lengthen the distance between the one end side and the other end side of the output shaft 4 supported by the end portion of the front housing 11 via the bearing 25, and the pinion gear 5 meshes with the ring gear 6. In addition, the shaft support span can be made relatively long with respect to the overhang amount when the output shaft 4 jumps out to the engine side. As a result, the stress generated in the output shaft 4 during engine cranking can be reduced, and the starter 1 having a more stable cantilever support structure can be provided. Further, by reducing the stress of the output shaft 4, the output shaft 4 can be reduced in diameter and weight.

  In the starter 1 described in the first embodiment, the ring-shaped engaging member 28 is directly fixed to the outer periphery of the output shaft 4 (small diameter portion) protruding from the end surface of the tube 3. In this case, the diameter of the engaging member 28 can be reduced as compared with the starter of the prior application described in “Background Art”, and accordingly, the outer diameter of the front housing 11 that accommodates the engaging member 28 is reduced. This makes it difficult to receive restrictions on engine mounting, and the degree of freedom in mounting to the engine is improved.

  Further, by directly fixing the engaging member 28 to the output shaft 4, there is no need to form a long groove (long groove along the helical angle of the helical spline) in the tube 3, and the output shaft 4 is connected via a pin or the like. Therefore, it is not necessary to connect the engaging member 28 to the engaging member 28. Therefore, the number of parts can be reduced, the structure can be simplified, and the parts can be easily assembled. Furthermore, since it is not necessary to extend the other end of the tube 3 to the end of the front housing 11, the total length of the tube 3 can be shortened, and the diameter of the engaging member 28 and the diameter of the output shaft 4 described above can be reduced. The weight of the starter 1 can be reduced.

  Further, when the output shaft 4 moved to the engine side is pushed back, the engaging member 28 fixed to the output shaft 4 comes into contact with the end surface of the tube 3, so that the tube 3 receives the retreating force of the output shaft 4 and receives the output shaft. Since it functions as a stopper that stops 4, it is not necessary to use a separate part for receiving the retracting force of the output shaft 4, and the stopper function can be configured at low cost.

  A return spring 27 for pushing back the output shaft 4 is disposed between the inner periphery of the tube 3 and the outer periphery of the output shaft 4, and a step portion 4 b (spring receiving portion) provided on the output shaft 4, and the tube 3 is supported by a spring receiving portion 3c provided on the base plate 3. According to this configuration, even when the pinion gear 5 is rotated by the ring gear 6 after the engine is ignited and the output shaft 4 is in an overrun state, there is almost no relative rotational difference between the output shaft 4 and the tube 3 (the output shaft 4 And the tube 3 rotate substantially integrally), a rotation absorbing member such as a washer is not required for the return spring 27.

  In the starter 1 described in the first embodiment, for example, a ball bearing is used as the bearing 21 that supports the inner periphery of one end of the tube 3 with respect to the bearing portion 8b provided on the armature shaft 8a. The outer ring 21b is press-fitted and fixed to the inner periphery of the tube 3, and the inner ring 21a is assembled with a gap fitted to the outer periphery of the bearing portion 8b. According to this configuration, the ball bearing functions as a retainer for the output shaft 4 when the components of the starter 1 are assembled. That is, the ball bearing (bearing 21) can prevent the output shaft 4 from slipping out of the tube 3 due to the reaction force of the return spring 27, so that subsequent parts can be easily assembled.

In addition, the starter 1 described in the first embodiment includes a planetary gear reduction device that reduces the rotation of the motor 2, and the gear shaft 16 that supports the planetary gear 15 is integrated with the carrier portion 20 of the clutch outer 17 or separately. Is fixed. In addition, a circular fitting hole is formed in the radially central portion of the carrier portion 20 so as to be fitted to the outer periphery of one end side of the tube 3 so as to be relatively rotatable.
According to this configuration, the clutch outer 17 is centered on the armature shaft 8a via the planetary gear reduction device, and the clutch inner 18 (tube 3) is also centered on the armature shaft 8a via the bearing 21. The eccentricity of the clutch can be prevented, and stable clutch performance can be secured.

FIG. 5 is a cross-sectional view of the starter 1 according to the second embodiment.
The starter 1 according to the second embodiment is a type in which the rotation speed of the armature 8 is not reduced, and is transmitted to the tube 3 via the clutch. The major difference from the starter 1 described in the first embodiment is In other words, no reduction gear is provided between the motor 2 and the clutch. Other structures are basically the same as those of the starter 1 described in the first embodiment.
Here, a difference from the starter 1 described in the first embodiment, that is, a connection structure between the motor 2 and the clutch will be described.

  The clutch has an outer plate 17a provided integrally with the clutch outer 17, and a driven gear 17b (or a direct spline) is formed inside a hollow hole opened at the radial center of the outer plate 17a. The gear 17b (or direct spline) is engaged with a drive gear 8c (or direct spline) formed on the armature shaft 8a, and the clutch outer 17 is directly driven by the motor 2.

  Even in the above configuration, the output shaft 4 can be stably supported without having the speed reducer, which is the same as the starter 1 of the first embodiment, and the starter 1 having a stable cantilever support structure can be provided. Further, since the clutch outer 17 is directly centered on the armature shaft 8a, and the clutch inner 18 (tube 3) is also centered on the armature shaft 8a via the bearing 21 (ball bearing), the eccentricity of the clutch is prevented. And stable clutch performance can be secured.

(Modification)
In Example 1 and Example 2, as a means for moving the output shaft 4 to the engine side, the rotation restricting rod 29 is engaged with the engaging member 28 fixed to the output shaft 4 to restrict the rotation of the output shaft 4. In this state, a method of moving the output shaft 4 to the engine side by the rotational force of the motor 2 and the action of the helical spline is adopted, but the output shaft 4 is used by using a shift lever adopted in a general starter. The method of extruding may be used. In other words, the shift lever is driven by the electromagnetic force of the electromagnetic switch 31, and the force that pushes it in the axial direction is applied to the engaging member 28 fixed to the output shaft 4 via the shift lever, whereby the output shaft 4 is engine driven. It is a method of moving to the side.

  In addition, the starter 1 described in the first and second embodiments has a structure in which the tube 3 is supported by the two bearings 21 and 23, but the tube 3 is supported by only one bearing (for example, the bearing 23). Structure may be sufficient. In this case, as compared with the starter 1 described in the first and second embodiments, the effect of stably supporting the output shaft 4 may be slightly reduced, but the output shaft 4 protruding from the end surface of the tube 3 may be reduced. By directly fixing the engaging member 28 (for example, press-fitting), it is possible to reduce the diameter of the engaging member 28, thereby reducing the outer diameter of the front housing 11 (restriction in mounting the engine). Can be obtained).

  In the first embodiment and the second embodiment, the ball bearing is described as an example of the bearing 21. However, in addition to the ball bearing, a roller bearing using a roller as a rolling element or a plain bearing called a plain bearing is used as the bearing 21. It can also be used as

1 is a sectional view of a starter according to Embodiment 1. FIG. 2 is an enlarged cross-sectional view around a tube according to Example 1. FIG. It is sectional drawing of the bearing which supports the inner periphery of the tube which concerns on Example 1. FIG. 1 is an electric circuit diagram of a starter according to Embodiment 1. FIG. It is sectional drawing of the starter which concerns on Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Starter 2 Motor 3 Tube 3c Spring receiving part provided in inner periphery of tube 4 Output shaft 4b Step part (Spring receiving part provided in outer periphery of output shaft)
5 Pinion gear 6 Ring gear 8a Armature shaft (motor rotation shaft)
8b Bearing portion 8c Drive gear 11 Front housing (housing)
15 planetary gear 16 gear shaft 17 clutch outer 17a outer plate 17b driven gear 18 clutch inner 20 carrier portion 21 bearing (second bearing)
22 Center case (structure)
23 Bearing (third bearing)
25 Bearing (first bearing)
27 Return spring 28 Engagement member 29 Rotation restriction rod (rotation restriction member / drive means)
31 Electromagnetic switch (drive means)
A Main contact (contact means)
B Sub contact (contact means)

Claims (2)

A motor that generates rotational force;
A tube having a substantially cylindrical shape that rotates by transmitting the rotational force of the motor;
A clutch for intermittently transmitting power between the motor and the tube;
One end side in the axial direction is helically splined to the inner periphery of the tube, and the other end side in the axial direction is provided so as to protrude from the tube, and is rotatable and slid through a first bearing fixed to the housing. An output shaft supported freely,
An integral or separate arrangement at the end of the output shaft that protrudes outward from the first bearing (on the opposite side of the tube) for transmitting the rotational force transmitted from the tube to the output shaft to the engine ring gear With pinion gears,
An output shaft moving means for moving the output shaft to the engine side in order to mesh the pinion gear with the ring gear,
The tube has an inner circumference on one end side of the substantially cylindrical shape supported by a bearing portion provided on a rotating shaft of the motor via a second bearing so as to be relatively rotatable, and an outer circumference on the other end side of the substantially cylindrical shape. Is supported rotatably on the housing or a structure supported by the housing via a third bearing,
The output shaft moving means includes an engaging member fixed to the output shaft that protrudes in the direction opposite to the motor from the tube, and a driving means that applies a force pushing the output shaft in the axial direction through the engaging member. equipped with a,
The clutch includes a clutch outer that is rotated directly or indirectly by the motor, an outer plate that is provided integrally with the clutch outer, and a clutch inner that is rotated by transmission of power from the clutch outer. The clutch inner is formed as a part of the tube, and a driven gear or a straight spline is formed inside a hollow hole opened in a radial central portion of the outer plate. A starter characterized in that the clutch outer is directly driven by the motor by meshing with a drive gear or a straight spline formed on the rotating shaft of the motor . A motor that generates rotational force;
A tube having a substantially cylindrical shape that rotates by transmitting the rotational force of the motor;
A clutch for intermittently transmitting power between the motor and the tube;
One end side in the axial direction is helically splined to the inner periphery of the tube, and the other end side in the axial direction is provided so as to protrude from the tube, and is rotatable and slid through a first bearing fixed to the housing. An output shaft supported freely,
An integral or separate arrangement at the end of the output shaft that protrudes outward from the first bearing (on the opposite side of the tube) for transmitting the rotational force transmitted from the tube to the output shaft to the engine ring gear With pinion gears,
An output shaft moving means for moving the output shaft to the engine side in order to mesh the pinion gear with the ring gear,
The tube has one end side inner periphery of the substantially cylindrical, the bearing portion provided on the rotation shaft of the motor, rotatably supported via a second bearing that is press-fitted into the inner periphery of the tube The outer periphery of the other end of the substantially cylindrical shape is rotatably supported by the housing or a structure supported by the housing via a third bearing,
The output shaft moving means includes an engaging member fixed to the output shaft that protrudes in the direction opposite to the motor from the tube, and a driving means that applies a force pushing the output shaft in the axial direction through the engaging member. With
The clutch includes a clutch outer that is rotated directly or indirectly by the motor, an outer plate that is provided integrally with the clutch outer, and a clutch inner that is rotated by transmission of power from the clutch outer. The clutch inner is formed as a part of the tube, and a driven gear or a straight spline is formed inside a hollow hole opened in a radial central portion of the outer plate. A starter characterized in that the clutch outer is directly driven by the motor by meshing with a drive gear or a straight spline formed on the rotating shaft of the motor .

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