JP2016205238A - Engine starting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a gear and a mechanism on an inner part of an engine starting device when an abnormal torque is applied to the pinion gear side from the ring gear side.SOLUTION: A pinion moving body part 30 which is subjected to helical spline connection to an output shaft and slides in the axial direction includes: a pinion gear 31 which is engaged with a ring gear of an engine and performs torque transmission; an over-running clutch part which rotates the pinion gear 31 engaged with the ring gear by means of the engine and, when the rotation of the pinion gear is quicker than a rotation of the output shaft, causes the pinion gear to idle; and an interception mechanism part 34 which causes the clutch part to intercept torque transmission when a torque value satisfies prescribed conditions with respect to a direction of the torque transmission in accordance with motor rotation. The interception mechanism part 34 includes a pair of transmission members 341, 342 opposite to each other on a flat surface vertical to the axial direction and a spring member 37 which presses the transmission members 341, 342 in the axial direction, and the transmission members 341, 342 have transmission faces having an inclination of 30° to 60° with respect to the flat surface respectively vertical to the axial direction.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an engine starting device for starting an engine.

  Conventionally, an engine starting device for starting an engine performs an engine starting operation in a state where the engine is stopped. Therefore, the pinion gear provided in the engine starting device is engaged with the ring gear in a state where the ring gear provided in the engine is not rotating. However, in recent years, in a system that performs idling stop to reduce fuel consumption, the pinion gear may mesh with the ring gear even during rotation of the ring gear in order to ensure engine restartability.

  For example, if a restart request is made immediately after idling is stopped and the engine has not stopped rotating, or when it is necessary to reduce the time when restarting from the engine stopped state, the ring gear Is engaged with the pinion gear in advance during rotation. In such a case, as a method of meshing the pinion gear while the ring gear is rotating, the pinion gear is pushed out so that the pinion gear meshes with the ring gear when the rotational speed of the pinion gear and the ring gear is between a predetermined rotational speed difference. .

  In such a case, the meshing between the pinion gear and the ring gear at the time of reverse rotation of the engine may increase the impact. Therefore, it is possible to control to delay the rotation start timing of the motor provided in the engine starter than usual. There has been proposed an engine starter that uses a switch to delay the rotation start timing of the motor and avoids the meshing of the pinion gear and the ring gear during reverse rotation of the engine, thereby avoiding an impact (for example, Patent Document 1). reference).

  Alternatively, in order to reduce the impact caused by the meshing of the pinion gear and the ring gear, an engine starting device is also proposed in which an impact mitigating mechanism is provided in the deceleration mechanism portion of the engine starting device so as to mitigate the impact caused by the meshing of the pinion gear and the ring gear. (For example, refer to Patent Document 2).

JP 2012-031819 A JP 2010-255590 A

  In the case of an engine starter that reduces the impact caused by the engagement of the pinion gear and the ring gear, as in the engine starter proposed in Patent Document 1 or 2, the impact received by the pinion is transmitted through the overrunning clutch portion and the helical spline. Since the torque is generated when the torque is transmitted to the ring gear, the helical spline is damaged. Also, abnormalities such as ring gears being worn and deformed due to a large impact torque due to reverse rotation of the engine may occur, and as a result, damage to the engine starter's helical spline, pinion gear, etc. may occur. There is.

  The damage of the helical spline and pinion gear due to the impact torque from the ring gear side is not only due to the impact torque during reverse rotation of the ring gear at the idling stop, but also at the time of key start in the idling stop equipped car Even when the ring gear is completely stopped and then restarted, if an abnormality occurs and the pinion gear stops rotating, an abnormally large impact torque is applied to the helical spline or pinion gear. In the impact mitigation structure proposed in No. 2, it is inevitable that the helical spline and pinion gear are greatly damaged. Further, when the pinion gear is locked and an abnormally large impact torque is applied to the helical spline or the pinion gear, this may occur even in a vehicle not equipped with an idling stop.

  The present invention has been made to solve such a problem. When an abnormal torque is applied from the ring gear side to the pinion gear side, the engine starter that can protect the gear and mechanism provided in the engine starter is provided. The purpose is to obtain a device.

An engine starter according to the present invention includes a motor unit, a pinion gear that can mesh with a ring gear connected to the engine, a pinion moving body unit that is helically splined to the output shaft of the motor unit and is movable in the axial direction. An engine starter comprising: an extruding mechanism for moving the pinion moving body to a position where the pinion gear meshes with the ring gear; and a solenoid switch having a switch for turning on and off the energization current to the motor. Because
The pinion moving body unit includes an overrunning clutch unit that idles when the pinion gear meshed with the ring gear is driven by the engine via the ring gear and rotates at a higher speed than the rotation of the output shaft, and the overrunning clutch unit A shut-off mechanism portion that shuts off the transmission of the torque to the ring gear when the torque value is in a predetermined condition with respect to the direction in which the running clutch portion transmits the torque generated by the rotation of the motor portion to the ring gear. The blocking mechanism portion includes a pair of transmission members opposed to each other in a plane perpendicular to the axial direction, and a spring member that presses the pair of transmission members in the axial direction. Each has a torque transmission surface having an inclination of 30 ° to 60 ° with respect to a plane perpendicular to the axial direction.

  According to the engine starter according to the present invention, when the abnormal torque is generated from the ring gear side, the pinion moving body portion is provided with the shut-off mechanism portion that cuts off torque transmission in the direction of torque transmission. The gear and mechanism inside the starter can be protected from abnormal impact. Further, the torque transmission surfaces of the pair of transmission members constituting the shut-off mechanism portion are inclined at an angle of 30 ° to 60 ° with respect to a plane perpendicular to the axial direction, thereby suppressing the shape expansion of the overrunning clutch. And variations in the idling torque value due to fluctuations in the friction coefficient can be reduced.

1 is an exploded perspective view of an engine starter according to Embodiment 1 of the present invention. 1 is a cross-sectional view of an engine starter according to Embodiment 1 of the present invention. It is a disassembled perspective view of the pinion moving body part of the engine starting device according to Embodiment 1 of the present invention. It is a block diagram of the overrunning clutch part of the engine starting device by Embodiment 1 of this invention. It is a perspective view of the transmission member by the side of the output shaft of the engine starting device by Embodiment 1 of this invention. It is a perspective view of the transmission member by the side of the pinion gear of the engine starting device by Embodiment 1 of this invention. It is sectional drawing of the pinion moving body part of the engine starting device by Embodiment 1 of this invention. It is explanatory drawing of the interruption | blocking mechanism part of the engine starting apparatus by Embodiment 1 of this invention. It is an operation | movement image figure of the interruption | blocking mechanism part of the engine starting apparatus by Embodiment 1 of this invention. It is a graph which shows the variation of the idling torque value by the fluctuation | variation of the torque transmission surface angle and friction coefficient of the engine starting apparatus by Embodiment 1 of this invention, and the relationship between a torque transmission surface angle and a spring load.

Embodiment 1 FIG.
Hereinafter, an engine starter according to Embodiment 1 of the present invention will be described in detail with reference to the drawings. 1 is an exploded perspective view of an engine starter according to Embodiment 1. FIG. The engine starter according to the first embodiment includes a motor unit 10, an output shaft 20, a pinion moving body unit 30, a solenoid switch unit 40, a plunger 50, a lever 60, a bracket 70, a stopper 80, and a reduction gear unit 90. Yes. Plunger 50 and lever 60 constitute an extrusion mechanism.

  The motor unit 10 generates a rotational force for starting an engine (not shown). The output shaft 20 is coupled to the motor unit 10 via a reduction gear unit 90. The pinion moving body 30 is helically splined to the output shaft 20 and can slide on the peripheral surface of the output shaft 20 in the axial direction of the output shaft 20.

  The solenoid switch unit 40 is a suction coil, which will be described later, provided inside when a key switch of the vehicle is turned on or when an on command is issued from the engine control device (hereinafter referred to as ECU) to the engine starting device. When the current flows through and is excited, the plunger 50 is attracted. The lever 60 has a substantially central portion rotatably supported, one end engaged with the plunger 50 and the other end engaged with the pinion moving body 30. When the plunger 50 is attracted by the suction coil and moves toward the solenoid switch unit 40, one end of the lever 60 moves together with the plunger 50, and the pinion moving body unit 30 engaged with the other end of the lever 60 is moved to the solenoid switch unit 40. Extrude to the opposite side. The bracket 70 fixes each component including the motor unit 10, the output shaft 20, and the pinion moving body unit 30 to the engine side.

  FIG. 2 is a cross-sectional view of the engine starting device according to Embodiment 1, showing a state where the engine starting device is attached to the engine. In FIG. 2, when starting the engine, the key switch of the vehicle is turned on or an on command for the engine starting device is issued from the ECU. As a result, a current flows through the suction coil 41 of the solenoid switch unit 40 and the plunger 50 is sucked into the suction coil 41. When the plunger 50 is attracted by the suction coil 41, one end of the lever 60 is drawn toward the solenoid switch portion 40 and rotates counterclockwise in FIG.

  When the lever 60 rotates counterclockwise, the other end of the lever 60 pushes the pinion moving body 30 to the right side in FIG. As a result, the pinion moving body portion 30 splined to the output shaft 20 rotates along the output shaft-side helical spline portion 21 as the first helical spline portion provided on the peripheral surface of the output shaft 20 while rotating. 2 is pushed to the right. Further, the plunger 50 is attracted by the suction coil 41 and comes into contact with the end of the contact shaft 42, and the contact shaft 42 is pushed leftward in FIG. 2 while compressing the spring 45. Thereby, the moving contact portion 43 provided on the contact shaft 42 bridges the pair of motor contacts 44a and 44b, energization to the motor portion 10 is started, and the motor of the motor portion 10 rotates. 2 denotes a ring gear connected to the engine.

  FIG. 3 is an exploded perspective view of the pinion moving body 30. In FIG. 3, the pinion moving body portion 30 is idled when the pinion gear 31 meshed with the ring gear 100 (see FIG. 1) and the pinion gear 31 are rotated by the engine and become larger than the rotational speed of the output shaft 20. The running clutch part 32, the clutch cover 33, the shut-off mechanism part 34, a lever locking part 35 that engages with the lever 60, and a stop part 36 that stops the lever locking part 35. The shut-off mechanism 34 cuts off the transmission of torque when the torque is in a predetermined condition to be described later with respect to the direction in which the torque due to the rotation of the motor is transmitted.

  FIG. 4 is a configuration diagram of the overrunning clutch unit 32. As shown in FIG. 4, the overrunning clutch portion 32 includes a clutch outer 321, a clutch inner 322, a clutch roller 323, and a clutch spring 324 that presses and urges the clutch roller 323.

  5 is a perspective view of the output shaft side transmission member as the first transmission member, FIG. 6 is a perspective view of the pinion gear side transmission member as the second transmission member, and FIG. 7 is a cross-section of the pinion moving body 30. The figure is shown. The blocking mechanism 34 includes an output shaft side transmission member 341 shown in FIG. 5, a pinion gear side transmission member 342 shown in FIG. 6, and spring members such as a disc spring 37 and a disc spring cover 371 shown in FIG. .

  As shown in FIG. 5, the output shaft side transmission member 341 includes a pinion moving body side helical spline portion 38 that meshes with the output shaft side helical spline portion 21 on its inner peripheral surface. In addition, the output shaft side transmission member 341 includes a claw portion 341c in a plane portion orthogonal to the direction in which the axis extends. The claw portion 341c includes a torque transmission surface 341a that protrudes from the flat surface portion of the output shaft side transmission member 341 in a direction in which the shaft center extends, and an inclination in which the height from the flat surface portion gradually decreases from the torque transmission surface 341a. The sliding surface 341b is formed on the surface. In the first embodiment, as shown in FIG. 5, four claw portions 341c are provided around the axis at predetermined angular intervals.

  As shown in FIG. 6, the pinion gear side transmission member 342 as the second transmission member is configured integrally with the clutch outer 321 of the overrunning clutch portion 32 and is a plane orthogonal to the direction in which the axis extends. The claw part 342c is provided in the part. The claw portion 342c includes a torque transmission surface 342a that protrudes from the flat surface portion of the pinion gear side transmission member 342 in a direction in which the shaft center extends, and an inclined surface that gradually decreases in height from the flat surface portion from the torque transmission surface 342a. It is comprised from the sliding surface 342b formed in this. In the first embodiment, as shown in FIG. 6, four claw portions 342c are provided around the axis at predetermined angular intervals.

  As shown in FIG. 7, the output shaft side transmission member 341 and the pinion gear side transmission member 342 are arranged so that the respective claw portions 341c and 342c face each other, and torque transmission of the claw portion 341c of the output shaft side transmission member 341 is performed. The surface 341a and the torque transmission surface 342a of the claw portion 342c of the pinion gear side transmission member 342 are in contact with each other, so that the output shaft side transmission member 341 and the pinion gear side transmission member 342 transmit rotational torque from one to the other. It is configured to be able to.

  The disc spring 37 is inserted between the axial end surface portion of the output shaft side transmission member 341 and the inner wall portion of the disc spring cover 371. The disc spring cover 371 is fixed integrally with the clutch cover 33 by caulking the edge of the clutch cover 33 to a groove portion 371a formed on the outer peripheral surface portion thereof. As will be described later, the disc spring 37 inserted between the disc spring cover 371 and the output shaft side transmission member 341 always moves the output shaft side transmission member 341 in the direction of the pinion gear side transmission member 342 with a predetermined initial load Fk1. Is pressed.

  Further, by assembling the disc spring 37 in such a manner that the inner diameter side of the disc spring 37 and the output shaft side transmission member 341 are in contact with each other, the output shaft side transmission member 341 and the disc spring cover 371 due to the disc spring load are The shear stress to be received can be reduced. Further, by making the disc spring 37 in the above-described mounting direction, the acting point of the disc spring load and the fulcrum of the output shaft side transmission member 341 and the distance between the acting point of the disc spring load and the fulcrum of the disc spring cover 371 are reduced. It is possible to reduce the load applied to each.

  Torque from the motor unit 10 is transmitted from the output shaft side helical spline unit 21 provided on the output shaft 20 to the pinion moving unit 30 through the pinion moving unit side helical spline unit 38. Torque from the motor unit 10 transmitted to the pinion moving body side helical spline unit 38 is transmitted from the torque transmission surface 341 a of the output shaft side transmission member 341 to the torque transmission surface 342 a of the pinion gear side transmission member 342, and the overrunning clutch unit 32. The clutch outer 321, the clutch roller 323, and the clutch inner 322 are transmitted to the pinion gear 31. The torque from the motor unit 10 transmitted to the pinion gear 31 is transmitted to the ring gear 100 of the engine and starts the engine.

  Conversely, if torque is generated by reverse rotation from the engine side, torque due to reverse rotation of the engine is transmitted to the output shaft 20 through a path reverse to the above. FIG. 8 shows an operation image of the blocking mechanism 34 at that time. That is, FIG. 8 is an explanatory diagram of the shut-off mechanism 34, and the force applied to the pinion gear-side transmission member 342 and the output shaft-side send member 341 in the shut-off mechanism 34 when torque is generated by reverse rotation from the engine side. Shows the relationship.

7 and 8, when the disc spring 37 is assembled between the disc spring cover 371 and the output shaft side transmission member 341, the direction in which the shaft center of the output shaft side transmission member 341 extends (hereinafter referred to as the shaft). The initial load Fk <b> 1 is referred to as a direction) is set to be applied to the output shaft side transmission member 341. Here, the initial load Fk1 is expressed as follows.
Initial load Fk1 = K × S
Here, K is a spring constant of the disc spring 37, and S is an initial deflection amount of the disc spring 37. In FIG. 8, as will be described later, the disc spring 37 is further compressed from the initial setting and is deflected more than the initial deflection amount S, and a load Fk larger than the initial load Fk1 is applied to the output shaft side transmission member 341. Is shown.

  When the ring gear 100 of the engine rotates reversely and torque T is applied to the pinion gear 31 and the overrunning clutch portion 32, a force F perpendicular to the abutting torque transmission surface 341a and torque transmission surface 342a is applied. Here, the torque transmission surface 341a and the torque transmission surface 342a have an inclination of θ with respect to a plane perpendicular to the axis of the output shaft side transmission member 341 and the pinion gear side transmission member 342, respectively. Therefore, the torque T due to the reverse rotation of the engine described above is actually generated as Fsinθ through the torque transmission surfaces 341a and 342a and transmitted from the pinion gear side transmission member 342 to the output shaft side transmission member 341. At this time, an axial reaction force Fcosθ acts on the torque transmission surfaces 341a and 342a.

  Here, when the relationship between the initial load Fk1 by the disc spring 37 and the axial reaction force Fcosθ is Fk1 <Fcosθ, the disc spring 37 is further compressed and deflected compared to the initial setting. Accordingly, when the torque T increases and the axial reaction force Fcosθ becomes larger than the initial load Fk1 of the disc spring 37, the disc spring 37 starts to bend further from the initial deflection amount S.

  FIG. 9 is an operation image diagram of the blocking mechanism unit 34. FIG. 9A shows that the axial reaction force Fcosθ is equal to or less than the initial load Fk of the disc spring 37, and the torque transmitted from the engine ring gear 100 to the pinion gear 31 due to the reverse rotation of the engine is transmitted to the pinion gear side. The state where the member 342 is transmitted to the output shaft side transmission member 341 is shown.

  Next, if the torque T due to the reverse rotation of the engine is greater than a predetermined value, the axial reaction force Fcosθ becomes larger than the initial load Fk1 of the disc spring 37, and the disc spring 37 is further compressed from the initial compression amount S as described above. However, if the amount of deflection becomes larger than the stroke L in the axial direction in which the torque transmission surface 341a of the output shaft side transmission member 341 and the torque transmission surface 342a of the pinion gear side transmission member 342 are engaged, FIG. As shown in FIG. 9B, the torque transmission surface 341a of the output shaft side transmission member 341 and the torque transmission surface 342a of the pinion gear side transmission member 342 are not meshed, and the output shaft side transmission member 341 and the pinion gear side transmission member 342 are It will be idle.

  That is, when the output shaft side transmission member 341 and the pinion gear side transmission member 342 shown in FIG. 9B are idle, the load Fk2 by the disc spring 37 is Fk2 = K × (S + L). When the amount of deflection of the disc spring 37 reaches (S + L), when the relationship between the load Fk2 of the disc spring 37 and the axial reaction force Fcosθ is Fk2 <Fcosθ, the output shaft side transmission member 341 And the pinion gear side transmission member 342 idle.

  After the output shaft side transmission member 341 and the pinion gear side transmission member 342 start idling as shown in FIG. 9 (b), the sliding surface 341b of the output shaft side transmission member 341 is shown in FIG. 9 (c). And the sliding surface 342b of the pinion gear side transmission member 342 abut against each other and slip while slipping, and the next torque transmission surface 341a1 meshes with the torque transmission surface 342a to transmit torque. Accordingly, the above-mentioned idling is schematically illustrated in FIG. 9 until the next torque transmission surface 341a1 of the output shaft side transmission member 341 contacts the torque transmission surface 342a of the pinion gear side transmission member 342. And the pinion gear side transmission member 342 idle.

  The idling time is determined by the number of claw portions 341c and 342c provided on the output shaft side transmission member 341 and the pinion gear side transmission member 342, respectively. In the first embodiment, since the number of claw portions 341c and 342c provided on the output shaft side transmission member 341 and the pinion gear side transmission member 342 is four, torque is transmitted again after idling 90 °. Accordingly, if the torque T due to the reverse rotation of the engine is larger than a predetermined value, the idling is repeated for a certain period of time.

  In the above description, the case where the engine rotates reversely and torque is applied from the engine side to the pinion gear 31 side has been described. For example, even when the pinion gear 31 that is locked on the engine side and meshed with the ring gear 100 is locked, Similarly to the above, the output shaft side transmission member 341 and the pinion gear side transmission member 342 idle.

  By providing the claw portions 341c and 342c for each fixed angle as described above, the idling time can be set by the number of the claw portions 341c and 342c. Moreover, the inclination of the sliding surfaces 341b and 342b can be set arbitrarily. For example, if the angle of the inclined surface is made a gentle angle, the frictional force when the output shaft side transmission member 341 and the pinion gear side transmission member 342 are idling increases, and the frictional force is converted into heat energy. Therefore, the amount of energy absorbed by the impact applied to the pinion gear 31 is increased. Therefore, in this case, not only does it idle when it receives a large impact, but it also has an impact absorbing effect.

  Further, when the engine is started, the above-described axial reaction force Fcosθ generated on the torque transmission surfaces 341a and 342a due to the impact torque caused by the pulsation of the engine is equal to or greater than the initial load Fk1 of the disc spring 37, and the disc spring 37 is in the initial state. If the load Fk2 or less of the disc spring 37 when the deflection is further from the deflection amount S to the stroke L, the output shaft side transmission member 341 and the pinion gear side transmission member 342 are idling only by sliding the torque transmission surfaces 341a and 342a. Never do. Even when the engine pulsates during cranking of the engine, the impact sound generated from the pinion gear 31 and the ring gear 100 can be reduced by the deflection of the disc spring 37.

  As described above, the torque transmission surface 341a of the output shaft side transmission member 341 and the torque transmission surface 342a of the pinion gear side transmission member 342 are planes perpendicular to the axes of the output shaft side transmission member 341 and the pinion gear side transmission member 342, respectively. With an inclination of θ. Here, although the torque transmission surface angle θ can be arbitrarily set, the expansion of the shape of the overrunning clutch portion 32 can be suppressed by limiting the inclination to 30 ° or more with respect to the axial direction.

  Calculation formulas used for designing the disc spring 37 are shown in the following formulas (1) to (4) (see JIS B2706).

  The spring load is defined by the following equation (5).

  The stress calculation formula is defined by the following formulas (6) to (9).

In the above equations, D is the outer diameter (mm) of the disc spring 37, d is the inner diameter (mm) of the disc spring 37, t is the thickness (mm) of the disc spring 37, and r is the chamfer radius of the corner (mm). , H0 is the total deflection (mm) of the disc spring 37, E is the longitudinal elastic modulus (N / mm ² ), ν is the Poisson's ratio, and δ is the deflection (mm) of the disc spring 37. Note that h0 = H0−t, and H0 is the free height (mm) of the disc spring 37.

When the idling torque and the deflection of the disc spring 37 are considered to be constant, if the torque transmission surface angle θ is reduced, the load of the disc spring 37 must be increased (see formula (14) described later). In order to increase the load of the disc spring 37, it is necessary to increase the thickness t of the disc spring 37 (see the above formula (5)). In order to relieve the stress that increases by the amount of increase, it is necessary to increase the outer diameter D of the disc spring 37 (refer to the equations (6) to (9)). That is, it enlarges the shape of the overrunning clutch portion 32, and it is difficult to establish it as a starter.

  FIG. 10 is a graph showing the variation of the idling torque value due to the variation of the torque transmission surface angle θ and the friction coefficient μ, and the relationship between the torque transmission surface angle θ and the spring load. The main axis is the relationship between the torque transmission surface angle θ and the spring load. Is shown. It can be seen from FIG. 10 that the spring load increases as the torque transmission surface angle θ decreases. The spring load suddenly increases when the torque transmission surface angle θ is around 30 °. Therefore, the outer diameter expansion of the disc spring 37 can be suppressed by setting the torque transmission surface angle θ to 30 ° or more. That is, it is possible to suppress the shape expansion of the overrunning clutch.

  Further, by limiting the torque transmission surface angle θ to an inclination of 60 ° or less with respect to the plane perpendicular to the axis, it is possible to reduce variations in the value of the idling torque due to the variation of the friction coefficient μ.

First, from the force relationship applied to the pinion gear side transmission member 342 and the output shaft side transmission member 341 in FIG. 8, the force F _X of the torque direction,
F _X = F (sin θ + μ cos θ) (10)
The axial force F _Y is
F _Y = F (cos θ−μ sin θ) (11)
The idling torque is given by the following formula (12).
Td = F _X × r (12)
Here, r is the radius (m) of the torque transmission surface, and Td is the idling torque (Nm).

Substituting equation (10) into equation (12),
Td = F (sin θ + μ cos θ) × r
F = Td / r × (sin θ + μ cos θ) (13)
Substituting equation (13) into equation (11),
F _Y = Td (cos θ−μ sin θ) / r (sin θ + μ cos θ)
Td = F _Y × r × {(sin θ + μ cos θ)
/ (Cos θ−μ sin θ)} (14)
Therefore, the idling torque Td is defined by the above formula (14).

In the above formula (14), for example, the idling torque when the friction coefficient μ = 0.3 is
Td (μ0.3) = F _Y × r × {(sin θ + 0.3 cos θ)
/ (Cos θ−0.3 sin θ)} (15)
The idling torque when the friction coefficient μ = 0.2 is
Td (μ0.2) = F _Y × r × {(sin θ + 0.2 cos θ)
/ (Cos θ−0.2 sin θ)} (16)
The ratio Td (μ0.3) / Td (μ0.2) of the idling torque when the friction coefficient μ is changed from the equations (15) and (16) is expressed by the following equation (17).

  As can be seen from the equation (17), the ratio of the idling torque when the friction coefficient μ changes is determined by the angle of the torque transmission surface 341a and the torque transmission surface 342a with respect to the plane perpendicular to the axis and the friction coefficient μ. Is done.

  Further, the second axis in FIG. 10 shows the relationship between the torque transmission surface angle θ and the dispersion of the idling torque value by the above equation (17). As can be seen from the graph shown on the second axis in FIG. 10, it can be seen that the variation in the value of the idling torque due to the variation of the friction coefficient μ increases from the vicinity where the torque transmission surface angle θ exceeds 60 °. That is, by setting the torque transmission surface angle θ to 60 ° or less, it is possible to suppress the influence due to the variation of the friction coefficient μ and to stabilize the idling torque.

  As described above, the torque transmission surface 341a of the output shaft side transmission member 341 and the torque transmission surface 342a of the pinion gear side transmission member 342 constituting the shut-off mechanism 34 are respectively set to 30 ° with respect to a plane perpendicular to the axial direction. By setting the inclination to 60 ° or less, it is possible to suppress the shape expansion of the overrunning clutch portion 32 and to reduce the variation in the idling torque value due to the variation of the friction coefficient μ.

  As described above in detail, according to the engine starter according to the first embodiment, when an abnormal torque is generated from the ring gear 100 side, for example, when the pinion gear 31 and the ring gear 100 are engaged during the reverse rotation of the ring gear 100, Due to the impact of torque received from 100, idling occurs inside the pinion moving body 30. As described above, in the configuration in which idling occurs in the pinion moving body portion 30, the reduction gear portion 90 is subjected to a torque shock because it includes the shut-off mechanism portion 34 of a mechanism capable of idling to a position close to the pinion gear 31. Before transmission, idle rotation does not occur and the output shaft side helical spline portion 21, the pinion moving body side helical spline portion 38, and the like are not damaged. Further, it is possible to reduce the impact sound caused by the collision between the pinion gear 31 and the ring gear 100.

  The structure of the shut-off mechanism 34 is not only when the ring gear 100 is reversed, but also when the engine side is locked, the same mechanism is idled. Can suppress destruction of the internal mechanism.

  Further, according to the engine starter according to the first embodiment, for example, excessive impact torque is generated when the pinion gear 31 and the ring gear 100 are engaged while the engine is rotating in reverse during the conventional inertial rotation. In addition, since the pinion moving body 30 idles and absorbs the impact, it can be engaged even if the reverse rotational speed is large.

  Similarly, when the reverse rotation of the engine and the motor rotational force collide, since the impact and excessive torque can be reduced and idling by idling at a position closer to the pinion gear 31, control for delaying the motor rotation, etc. Even without this, it is possible to fully engage without damaging the helical spline. Therefore, not only the restart time is shortened, but also an integrated switch that can continuously push out the pinion gear 31 and rotate the motor can be used, and the cost and size can be reduced.

  In addition, since the torque can be transmitted by the claw portion 341c of the output shaft side transmission member 341 and the claw portion 342c of the pinion gear side transmission member 342, and a load that can idle by the load of the disc spring 37 can be set, the value of the idling torque that could not be achieved conventionally. Is easy to set. In other words, when the clutch roller 323 of the overrunning clutch portion 32 rotates in the power transmission direction, it transmits torque at the time of reverse rotation and torque of the motor rotation, but this portion absorbs the impact torque. In addition, the friction coefficient μ is not stable, and variation due to aging increases. However, according to the engine starting device according to the first embodiment, it is possible to suppress variations in mass production of the torque at which the shut-off mechanism 34 idles. Furthermore, as described above, it is possible to easily set a load for reducing noise during cranking.

  As described above, according to the engine starter according to the first embodiment, the torque setting can be easily performed in a small size, and the pinion gear 31 and the ring gear 100 are locked not only by reverse rotation of the engine but also by wear. Sometimes protection is possible easily. The shut-off mechanism 34 has a structure in which torque is transmitted by claws 341c and 342c provided on the output shaft side transmission member 341 and the pinion gear side transmission member 342, respectively, and the outer peripheral side of the pinion moving body side helical spline portion 38. Thus, since the overrunning clutch portion 32 and the shut-off mechanism portion 34 are connected by the clutch cover 33, it is possible to perform idling and transmission by a stable torque impact without increasing the size.

  In the above description, the engine starting device has been described when the ring gear 100 meshes with the pinion gear 31 and the ring gear 100 while the ring gear 100 is inertially rotated at the idling stop. However, when the ring gear 100 is meshed after the ring gear 100 is completely stopped at the idling stop, Even an engine starter for a vehicle without an idling stop can cause an abnormal impact torque if the motor starts rotating by locking the gear when it wears out. If this invention is applied, there is an effect.

  The embodiment of the present invention has been described above. However, the present invention is not limited to this embodiment, and these configurations may be appropriately combined or a part of the configuration may be modified without departing from the spirit of the present invention. It is possible to add or partially omit the configuration.

10 motor part, 20 output shaft, 21 output shaft side helical spline part, 30 pinion moving body part, 31 pinion gear, 32 overrunning clutch part, 321 clutch outer, 322 clutch inner, 323 clutch roller, 324 clutch spring, 33 clutch cover , 34 Blocking mechanism part, 341 Output shaft side transmission member, 341a, 342a Torque transmission surface, 341b, 342b Sliding surface, 341c, 342c Claw part, 342 Pinion gear side transmission member, 35 Lever locking part, 36 Stopping part, 37 Dish Spring, 371 Disc spring cover, 371a Groove, 38 Pinion moving body side helical spline, 40 Solenoid switch, 41 Suction coil, 42 Contact shaft, 43 Moving contact, 44a, 44b Motor contact, 45 Spring, 50 Nja, 60 lever 61 lever rotation axis center, 70 bracket, 80 a stopper, 90 a reduction gear unit, 100 a ring gear

An engine starter according to the present invention includes a motor unit, a pinion gear that can mesh with a ring gear connected to the engine, a pinion moving body unit that is helically splined to the output shaft of the motor unit and is movable in the axial direction. An engine starter comprising: an extruding mechanism for moving the pinion moving body to a position where the pinion gear meshes with the ring gear; and a solenoid switch having a switch for turning on and off the energization current to the motor. Because
The pinion moving body unit includes an overrunning clutch unit that idles when the pinion gear meshed with the ring gear is driven by the engine via the ring gear and rotates at a higher speed than the rotation of the output shaft, and the overrunning clutch unit A shut-off mechanism portion that shuts off the transmission of the torque to the ring gear when the torque value is in a predetermined condition with respect to the direction in which the running clutch portion transmits the torque generated by the rotation of the motor portion to the ring gear. ,
The blocking mechanism portion includes a pair of transmission members that are opposed to each other in a plane perpendicular to the axial direction, and a spring member that presses the pair of transmission members in the axial direction.
Each of the pair of transmission members includes a torque transmission surface having a predetermined inclination with respect to a plane perpendicular to the axial direction, and a sliding surface in which the angle of the inclined surface with respect to the torque transmission surface is set to a gentle angle. And
It said torque transmitting surface, with respect to a plane perpendicular to the respective axially, is also to that having a slope in the range of 60 ° from 30 °.

Claims (7)

A motor unit, a pinion gear that can mesh with a ring gear connected to the engine, a pinion moving body unit that is helically splined to the output shaft of the motor unit and formed to be movable in the axial direction, and the pinion moving body unit An engine starter comprising: an extruding mechanism unit that moves a pinion gear to a position that meshes with the ring gear; and a solenoid switch unit that includes a switch unit that turns on and off the energization current to the motor unit,
The pinion moving body part is:
An overrunning clutch portion that idles when the pinion gear meshed with the ring gear is driven by the engine via the ring gear and rotates at a speed higher than the rotation of the output shaft;
A blocking mechanism that blocks transmission of the torque to the ring gear when a value of the torque is a predetermined condition with respect to a direction in which the overrunning clutch unit transmits torque generated by rotation of the motor unit to the ring gear; With
The blocking mechanism portion includes a pair of transmission members that are opposed to each other in a plane perpendicular to the axial direction, and a spring member that presses the pair of transmission members in the axial direction.
The pair of transmission members each have a torque transmission surface having an inclination of 30 ° to 60 ° with respect to a plane perpendicular to the axial direction.   2. The engine starter according to claim 1, wherein the torque transmission surface has a different angle on a torque transmission side and an angle on a torque non-transmission side.   The engine starting device according to claim 1, wherein a plurality of the torque transmission surfaces are provided in a rotation direction. The engine starter is
An engine starter that operates the push-out mechanism and the switch to restart the engine during a deceleration period in which the engine stops;
The solenoid switch part is
The coil that operates the push-out mechanism and the switch unit is configured as one coil, and the plunger is further pulled into the coil while pushing out the pinion gear in the process of pulling the plunger of the push-out mechanism unit into the coil. 4. The engine starter according to claim 1, wherein when the operation is started, the main circuit of the motor unit is closed and driving of the motor unit is started. 5.   The engine starting device according to any one of claims 1 to 4, wherein the spring member is constituted by a disc spring and is provided on an outer peripheral side of the pair of transmission members.   6. The engine starter according to claim 5, wherein the disc spring is configured such that an inner diameter side presses the pair of transmission members toward the ring gear.   The initial load that presses the pair of transmission members in the axial direction by the disc springs is a load that does not block the transmission of the torque with the torque generated in the axial direction due to the torque when the output of the engine rises during normal startup The engine starter according to claim 5 or 6, wherein