JP5023201B2 - Engine starting torque transmission mechanism - Google Patents

Description

  The present invention relates to an engine start torque transmission mechanism that transmits torque for engine start to an engine crankshaft.

In general automobiles, in order to start the engine, a starter motor is energized, and the rotational force is transmitted to the crankshaft to rotate the crankshaft. That is, the engine is started by interposing a gear mechanism between the starter motor and the crankshaft and meshing the gears to transmit the rotational force. When the crankshaft rotates to complete the start, the meshing of the gears is released and the energization to the starter motor is stopped.
The engine start torque transmission mechanism of this automobile has a structure in which the gears are engaged at the start and the engagement is released after the start.

However, in recent years, in order to reduce carbon dioxide emissions and improve fuel efficiency, automobile engines are not idling when the automobile is temporarily stopped due to a signal, etc. It is requested to stop (idling stop).
In a car equipped with an idling stop system, the engine is automatically stopped when the vehicle is temporarily stopped. If it is determined that there is a restart request from the driver, an activation signal is sent to the starter motor, and the engine is automatically started instantaneously. As an engine starting rotational force transmission mechanism incorporated in such an automobile, a structure using a gear mechanism, a one-way clutch, a bearing or the like is considered.

FIG. 2 is a view showing a conventional example of such an engine starting rotational force transmission mechanism. First, the structure will be described, and then the operation will be described.
In FIG. 2, 1 is an engine starting torque transmission mechanism, 2 is a starter motor, 2P is a pinion gear, 3 is a ring gear, 4 is an engine block, 5 is a drive plate, 6 is a flywheel, 7 and 8 are oil seals, 9 is One-way clutch, 10 is a bearing, 11 is an inner race, 12 is an outer race, 13 is a one-way clutch operating part, 14 is an outer ring, 15 is a ball rolling element, 16 is an inner ring, 17 is a bolt, 18 is a crankshaft, 19 is a crank A bearing portion, 20 is an oil supply hole, 21 is an oil jet hole, and 22 is a crank bearing.

The pinion gear 2P is a gear rotated by the starter motor 2, and the rotational force for starting is transmitted from this gear. The ring gear 3 is a gear fixed to the outer periphery of the drive plate 5 and meshes with the pinion gear 2P.
A one-way clutch 9 and a bearing 10 are provided between the drive plate 5 and the crankshaft 18.

The bearing 10 includes an inner ring 16, a ball rolling element 15, and an outer ring 14, and the inner ring 16 is fixed to a crankshaft 18. The bearing 10 is disposed so that the drive plate 5 and the crankshaft 18 can rotate independently of each other.
The one-way clutch 9 is configured such that a one-way clutch operating unit 13 is sandwiched between an inner race 11 and an outer race 12. The one-way clutch actuating unit 13 is engaged so as to transmit the force when force is transmitted in a predetermined direction, and is operated so as not to transmit force when it is not engaged. Structure part. Specifically, in this figure, when the rotational speed of the inner race 11 is larger than the rotational speed of the outer race 12, the engaged state is established (rotational force transmission from the inner race 11 to the outer race 12), and otherwise it is released. It becomes a state.

Of the end portions of the inner race 11, the end portion that holds the one-way clutch operating portion 13 is fixed to the outer periphery of the outer ring 14, and the other end portion is fixed to the inner periphery of the drive plate 5 by welding or the like. . The end of the outer race 12 that is not sandwiching the one-way clutch operating portion 13 is fixed to the crankshaft 18 by a bolt 17.
The flywheel 6 is also fixed to the rear end of the crankshaft 18 with bolts 17.

The oil seal 7 is a seal disposed between the engine block 4 and the inner race 11, and seals between the two so that engine oil or the like does not leak.
The oil seal 8 is a seal disposed between the inner race 11 and the outer race 12, and removes engine oil or the like leaking from the engine block 4 side through the bearing 10 and the one-way clutch 9 from this position. I'm stopping here so I don't go out.

An oil jet hole 21 communicating with the oil supply hole 20 to the crank bearing 22 provided in the crank bearing portion 19 of the engine block 4 is opened by metal processing from the side surface of the crank bearing portion 19 facing the bearing 10 and the like. ing.
Lubricating oil is supplied from a pump (not shown), branches from a route lubricated by the crank bearing 22 and is ejected through the oil jet hole 21 to be used for lubrication of the bearing 10, the one-way clutch 9, the oil seal 8, and the like. . Lubricating oil and engine oil also play a role in preventing deterioration of oil seals and improving performance.

Next, the operation will be described.
(When starting)
The crankshaft 18 is stopped, and the inner ring 16 fixed integrally therewith is also stopped. When the starter motor 2 is activated, the rotational force is transmitted to the inner race 11 through the following route. Pinion gear 2P → ring gear 3 → drive plate 5 → inner race 11. The inner race 11 to which the rotational force is applied is fixed to the outer periphery of the outer ring 14 of the bearing 10 and is stopped because the ball rolling element 15 is interposed between the outer ring 14 and the inner ring 16. The inner ring 16 (integrated with the crankshaft 18) tries to rotate smoothly around it.

  The outer race 12 is fixed to the crankshaft 18 and is stopped together with the crankshaft 18. If the inner race 11 tries to rotate in this state, the inner race 11 rotates at a higher rotational speed than the outer race 12, so that the one-way clutch actuating portion 13 is engaged. As a result, the rotational force of the inner race 11 is transmitted to the outer race 12, the crankshaft 18 secured thereto starts to rotate, and the engine is started.

(After startup is complete)
When the rotational speed of the crankshaft 18 is increased after starting, and the rotational speed of the outer race 12 becomes larger than the rotational speed of the inner race 11, the one-way clutch operating unit 13 is released. Then, the engagement relationship between the inner race 11 and the outer race 12 is lost, and thereafter each moves independently.

Since energization to the starter motor 2 is eventually turned off, the pinion gear 2P also stops. Therefore, the ring gear 3 meshing with the pinion gear 2P also stops rotating, and the drive plate 5, the inner race 11 and the outer ring 14 connected to the tip of the ring gear 3 also stop rotating.
Since the inner ring 16 is fixed to the crankshaft 18, it continues to rotate together with the crankshaft 18. However, since the ball rolling element 15 is interposed between the outer ring 14 and the rotational force of the inner ring 16 is not transmitted to the outer ring 14, the outer ring 14 does not rotate continuously.

JP 2007-032492 A

(problem)
The above-described conventional engine starting rotational force transmission mechanism has the following problems.
The first problem is that this mechanism cannot be incorporated into any engine, and the engines that can be incorporated are limited.
The second problem is that the manufacturing cost is high.

(Explanation of problem)
First, the first problem will be described. While the engine is running, the outer race 12 continues to rotate at the engine speed, but the oil seal 8 that is in contact with the outer race 12 can withstand a predetermined performance regardless of the engine speed. It's not something you can do. As a value that can be used while maintaining the performance of the oil seal, there is a value that is a limit peripheral speed. If it is used in an environment that exceeds the limit value, it becomes difficult to maintain a predetermined performance, and such use must be avoided.

By the way, the peripheral speed is proportional to the product of the radius and the rotational speed. In a large engine (large radius) even at low speed rotation, the radius to the outer peripheral surface of the outer race 12 becomes large, so that the peripheral speed at the outer peripheral surface increases when the rotational speed is slightly increased. On the other hand, in a small engine designed to rotate at a high speed, the outer race 12 also rotates at a high speed, so that the peripheral speed on the outer peripheral surface becomes large. Therefore, in the engine as described above, the peripheral speed at the oil seal 8 may exceed the limit peripheral speed.
Therefore, such an engine starting rotational force transmission mechanism cannot be incorporated with peace of mind in such an engine. The engine can be incorporated only in engines that are not large and do not have a large number of revolutions. In other words, it is difficult to mount an idling stop system using this engine starting rotational force transmission mechanism in a large engine or a high-speed engine vehicle.

Next, the second problem will be described. The reason for the high manufacturing cost is mainly from the following.
(1) Although it is necessary to use a member having high hardness as the inner race 11, the conventional one has to be processed with high precision by polishing and the like, and its manufacturing cost has been high.
(2) The oil seal 8 that is in contact with the outer circumferential surface of the outer race 12 that is constantly rotating during operation is required to use one having a high marginal circumferential speed, but such a thing is expensive. It was.
(3) An oil jet hole 21 for jetting lubricating oil has to be formed for lubrication of the one-way clutch 9 and the bearing 10, and a metal processing fee is applied.
An object of the present invention is to solve the above problems.

In order to solve the above-described problems, in the present invention, a ring gear meshed with a pinion gear of a starter motor, a drive plate having an outer periphery fixed to the inner periphery of the ring gear, and a starting rotation between the drive plate and the crankshaft A one-way clutch that is disposed in the force transmission path and transmits a rotational force in only one direction from the drive plate side to the crankshaft side, and is disposed so that the drive plate and the crankshaft can rotate independently of each other. In an engine starting rotational force transmission mechanism comprising a bearing, a ring-shaped recess is provided on the side of a flywheel fixed to a crankshaft, and the bearing and the one-way clutch are filled with a lubricant to prevent lubricant leakage on both sides. used after subjected to sealing, the one-way clutch is disposed on the outer periphery of the bearing Bearing one-way clutch unit constituted by unitized so as to be both integrally accommodates and fixed to the ring-shaped recess, it was decided to fix the inner peripheral end portion of the drive plate to the outer ring side of the bearing.

As the bearing, a ball rolling element having a single row type may be used.

The engine starting rotational force transmission mechanism of the present invention has the following effects.
1. The types of engines that can be incorporated have greatly increased, and it has become possible to incorporate them into large engines (large radius) that have been considered difficult to incorporate in the past and engines that are designed for high-speed rotation.
The reason is that an oil seal corresponding to the oil seal 8 of the conventional example is not required, and only an oil seal installed at a position whose radius is significantly smaller than the position of the oil seal 8 is required. With this oil seal having a small radius, the peripheral speed is not so high when considered within the range of the rotational speed of the automobile engine. Therefore, there is almost no need to consider whether the peripheral speed is exceeded or not, and the types of engines that can be incorporated have greatly increased.

2. The manufacturing cost could be greatly reduced.
The inner race 11 had to be made of a member having a high hardness and had to be polished and finished with high precision. However, the inner race 11 was expensive because it was not necessary in the present invention. Further, the oil seal 8 having a high limit peripheral speed is expensive, but in the present invention, this is also unnecessary. Further, since the oil jet hole 21 is not required, the metal processing fee is not required. As a result, manufacturing costs have been greatly reduced.

The figure which shows the engine starting rotational force transmission mechanism of this invention The figure which shows the conventional engine starting rotational force transmission mechanism

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a view showing an engine starting rotational force transmission mechanism of the present invention. The reference numerals correspond to those in FIG. 2, 6A is a ring-shaped recess, 6B is an outer recess wall, 6C is an inner recess wall, 30 is a bearing one-way clutch unit, 31 is a unit case, 32 and 33 are seal bodies, and 34 is an oil seal. It is.

The structure shown in FIG. 1 is different from that shown in FIG. 2 in the following points.
(1) An annular recess 6 </ b> A is provided on the side surface of the flywheel 6.
(2) A bearing one-way clutch unit 30 configured by integrating the one-way clutch 9 and the bearing 10 into the annular recess 6A is housed and fixed.
(3) The drive plate 5 is fixed to the side surface of the outer ring 14 of the bearing 10.
(4) The one-way clutch 9 and the bearing 10 were filled with lubricant and sealed on both sides to prevent lubricant leakage.
(5) An oil seal 34 is provided between the engine block 4 and the crankshaft 18.

  As shown in FIG. 2, the one-way clutch 9 and the bearing 10 of the engine starting rotational force transmission mechanism are conventionally disposed on the engine block 4 side when viewed from the flywheel 6. Therefore, in the present invention, a ring-shaped recess 6A is provided on the side surface of the flywheel 6 so that the arrangement configuration is not destroyed, and the bearing one-way clutch unit 30 is accommodated and fixed therein.

Here, the bearing one-way clutch unit 30 refers to a unit body configured as follows. First, the one-way clutch 9 is filled with a lubricant (grease or the like) and sealed on both sides to prevent it from leaking out. Similarly, the bearing 10 is filled with a lubricant, and both sides are provided with seal bodies 33 so as not to leak out. The outer periphery of the bearing 10 (that is, the outer ring 14) is attached to the inner periphery of the one-way clutch 9, and these are accommodated and fixed in the unit case 31 so as to be integrated.
When the one-way clutch 9 and the bearing 10 are configured to be integrated, the outer ring 14 can also serve as the inner race of the one-way clutch 9 as shown in FIG.

The inner peripheral end of the drive plate 5 to which the ring gear 3 is fixed on the outer periphery is fixed to the side surface of the outer ring 14 (for example, by welding, mechanical connection, etc.).
Since the one-way clutch 9 and the bearing 10 according to the present invention are lubricated by the lubricant that has been filled in advance and held so as not to leak out, it is not necessary to have the lubricant supplied from the outside as in the prior art. Is reduced.

In addition, since there is no need for metal processing for forming the oil jet hole 21 in the crank bearing portion 19, the cost can be reduced.
The oil seal 34 prevents the engine oil from the engine block 4 side from leaking outside (prevents leakage from the oil seal 34 to the right).

The above is the structure when the bearing one-way clutch unit 30 is used. However, the engine starting rotational force transmission mechanism can be configured without using such a unit. That is, the configuration of the bearing one-way clutch unit 30 and the portion corresponding to the periphery thereof is configured as follows.
The one-way clutch 9 and the bearing 10 are accommodated and fixed in this order from the outside to the annular recess 6A provided in the flywheel 6. Out of the peripheral walls of the annular recess 6A, the outer recess wall 6B is a wall farther from the crankshaft 18, and the inner recess wall 6C is a near wall.

Therefore, when the above accommodation is performed, the outer periphery of the one-way clutch 9 is accommodated so as to be mechanically fixed to the outer concave wall 6B, and the inner ring 16 of the bearing 10 is accommodated so as to be mechanically fixed to the inner concave wall 6C. The outer ring 14 of the bearing 10 is fixed to the inner periphery of the one-way clutch 9.
The inner peripheral end of the drive plate 5 is fixed to the side surface of the outer ring 14 (for example, by welding, mechanical connection, etc.).
As the one-way clutch 9 and the bearing 10, like the above-described one, a lubricant is filled therein and seals are provided on both side surfaces to prevent leakage.
Comparing the unitized and non-unitized ones, the unitized ones are much easier to use, and if standardized, cost reduction can be expected by mass production.

Next, the operation will be described.
(When starting)
The crankshaft 18 is stopped, and the flywheel 6 and the inner ring 16 fixed integrally therewith are also stopped. When the starter motor 2 is activated, the rotational force is transmitted to the outer ring 14 of the bearing 10 through the path of the pinion gear 2P → the ring gear 3 → the drive plate 5 → the outer ring 14. The outer ring 14 tries to rotate smoothly with respect to the inner ring 16.
At this time, since the inner ring 16 is fixed integrally with the flywheel 6, when the outer ring 14 tries to rotate, the inner ring 16 rotates more than the stopped crankshaft 18. Then, the one-way clutch operating unit 13 is engaged, the rotational force of the outer ring 14 is transmitted to the flywheel 6, the crankshaft 18 secured thereto starts to rotate, and the engine is started.

(After startup is complete)
When the rotational speed of the crankshaft 18 is increased after starting, and the rotational speed of the outer recessed wall 6B (flywheel 6) becomes larger than the rotational speed of the outer ring 14, the one-way clutch operating unit 13 is released. Then, since there is no engagement relationship between the outer ring 14 and the outer recessed wall 6B (flywheel 6), each moves independently thereafter.
The outer ring 14 will eventually stop. This is because the energization of the starter motor 2 is eventually turned off, and the pinion gear 2P is also stopped. For this reason, the ring gear 3 meshing with the pinion gear 2P also stops rotating, and the drive plate 5 and the outer ring 14 connected to the ring gear 3 also stop rotating.
Since the inner ring 16 is fixed to the flywheel 6, it continues to rotate together with the crankshaft 18. However, since the ball rolling element 15 is interposed between the outer ring 14 and the rotational force cannot be transmitted to the outer ring 14, the outer ring 14 does not rotate continuously.

In the conventional example, the bearing 10 is a so-called double row type in which the ball rolling elements 15 have two rows. However, as shown in FIG. 1, if a single-row ball rolling element 15 is used, even if a moment load is generated due to lateral vibration of the ring gear 3 or the drive plate 5, alignment is provided. The durability of the bearing 10 can be improved.
It goes without saying that the engine start torque transmission mechanism of the present invention described above can be used not only for MT vehicles but also for AT vehicles.

  DESCRIPTION OF SYMBOLS 1 ... Engine starting rotational force transmission mechanism, 2 ... Starter motor, 2P ... Pinion gear, 3 ... Ring gear, 4 ... Engine block, 5 ... Drive plate, 6 ... Flywheel, 6A ... Ring-shaped recessed part, 6B ... Outer recessed part wall, 6C ... Inner recessed wall, 7, 8 ... Oil seal, 9 ... One-way clutch, 10 ... Bearing, 11 ... Inner race, 12 ... Outer race, 13 ... One-way clutch operating part, 14 ... Outer ring, 15 ... Ball rolling element, 16 ... Inner ring DESCRIPTION OF SYMBOLS 17 ... Bolt, 18 ... Crankshaft, 19 ... Crank bearing part, 20 ... Oil supply hole, 21 ... Oil jet hole, 22 ... Crank bearing, 30 ... Bearing one-way clutch unit, 31 ... Unit case, 32, 33 ... Sealing body , 34 ... Oil seal

Claims (2)

A ring gear meshed with the starter motor pinion gear;
A drive plate whose outer periphery is fixed to the inner periphery of the ring gear;
A one-way clutch that is disposed in a starting torque transmission path between the drive plate and the crankshaft, and transmits torque in only one direction from the drive plate to the crankshaft;
An engine starting torque transmission mechanism comprising a bearing arranged to allow the drive plate and the crankshaft to rotate independently of each other;
An annular recess is provided on the side of the flywheel fixed to the crankshaft,
The bearing and the one-way clutch are each filled with lubricant and sealed on both sides to prevent leakage of the lubricant, and the one-way clutch is arranged on the outer periphery of the bearing so as to be integrated into a unit. bearing one-way clutch unit, it accommodates and fixed to the ring-shaped recess,
Said drive plate of the inner peripheral edge portion of the engine startup torque transmitting mechanism, characterized in that <br/> which is adapted to secure the outer ring side of the bearing. 2. The engine starting rotational force transmission mechanism according to claim 1, wherein a ball rolling element having a single row type is used as a bearing .

Images