JPH0135085Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a segmented flywheel with low torsional rigidity, and in particular relates to technology for reducing sliding friction heat in the portion that performs the torque limiter function and technology for maintaining the effectiveness of engine braking. .

[Background Art] A torque fluctuation absorbing device is provided in a power transmission line of an engine of a vehicle or the like in order to absorb the torque fluctuation. As a torque fluctuation absorbing device, there is a split flywheel in which a vibration system is constructed by dividing the flywheel into a plurality of flywheels and connecting them with springs (for example, Japanese Patent Publication No. 56-43176, Utility Model No. Publication No. 113547 (Sho 59-113547).

The structure, operation, and characteristics of a conventional split flywheel will be explained with reference to FIGS. 5 to 7. That is, the flywheel is divided into a drive side flywheel 31 connected to the crankshaft 30 and a driven side flywheel 32 connected to the transmission side, and both flywheels 31 and 32 are arranged in the flywheel circumferential direction. They are connected via an extending spring 33 with low torsional rigidity. Both flywheels 3
A torque limiter 34 is interposed between the torque limiter 1 and the torque limiter 34, which slips when an abnormally large torque exceeding a set value is applied to release the abnormal torque. The torque limiter 34 usually has a friction material lining 3 on the outer surface of a pair of friction plates 35 and 36.
Attach 7, 38 and friction plate 3
A disc spring 39 is interposed between the friction plates 35 and 36 to urge the friction plates 35 and 36 away from each other, and the linings 37 and 38 are pressed against the driven flywheel 32.

If this kind of structure is represented by a vibration model, the sixth
The result will be as shown in the figure. That is, the drive side flywheel 31 and the driven side flywheel 32
The two inertial bodies are connected via a series mechanism of a spring 33 and a torque limiter 34, which constitute a low torsional rigidity spring.

In such a device, the fluctuating torque transmitted from the crankshaft 30 to the drive-side flywheel 31 is transmitted through the spring 33 and the torque limiter 34.
The signal is transmitted to the driven side flywheel 32 via. At this time, when the transmitted torque is less than the set value _T0 , no slipping occurs in the torque limiter 34, but
When the torque exceeds the set value _T0 , slippage occurs in the torque limiter 34, which means that the linings 37, 3
8 and the driven flywheel 32, and as shown in FIG. 7, further torque transmission is cut off.

[Problems to be solved by the invention] However, as mentioned above, in a split flywheel with a torque limiter, when resonance occurs, etc.
If an abnormally large torque acts and causes the torque limiter to slide, the frictional heat will also increase and the torque transmission capacity will decrease. Therefore, even when the vehicle is operating with normal torque, the torque limiter slides, creating a vicious cycle in which the frequency of frictional heat generation increases. An effective way to reduce frictional heat is to reduce the friction force when the torque limiter slips, but reducing the friction force may reduce the effectiveness of engine braking when the torque limiter slips. A problem arises.

The purpose of this invention is to reduce the generation of frictional heat during sliding while maintaining the function of the torque limiter in a low torsionally rigid split flywheel, and to maintain good engine braking effectiveness. Moreover, the purpose is to achieve this with a simple structure, thereby making it possible to obtain smaller size, lighter weight, lower cost, and higher reliability.

[Means for solving the problem] The low torsional stiffness split type flywheel of the present invention that meets this purpose has a drive side flywheel, an intermediate flywheel, and a driven side flywheel on the same axis, and the drive side flywheel and an intermediate flywheel are connected via a spring, and a check ball is provided on one side of the intermediate flywheel and the driven flywheel, and a check ball is provided on the other side, and a check ball is provided on the other side. An acceptable check ball engagement groove is provided, and the check ball is connected so as to be engageable and detachable via the check ball.
It consists of a one-way clutch connected in parallel to the check ball and transmitting only negative torque.

[Operation] In the low torsionally rigid split type flywheel having the above configuration, during normal operation, the check ball is accommodated in and engaged with the check ball engagement groove, and the intermediate flywheel and the driven flywheel rotate as one. . Therefore, the drive side flywheel is connected to the intermediate flywheel and the driven side flywheel via the spring, and the torque fluctuation reducing effect inherent to the split type flywheel can be effectively achieved.

On the other hand, if the transmitted torque becomes abnormally large, the one-way clutch releases the torque transmission in the positive torque direction, causing the check ball to climb up on the bank of the check ball engagement recess, causing the spring that biases the check ball to Overcoming the force, the check ball comes out of the engagement groove, and the intermediate flywheel and the driven flywheel rotate relative to each other due to the slip of the check ball to escape the abnormal torque. At this time, the pressing force is only the urging force of the check ball by the spring, so the torque at the time of slipping is small, the sliding friction is also small, and the frictional heat can be reduced.

However, even when the transmitted torque is abnormally large,
For negative torque transmission, the one-way clutch transmits the torque and no slippage of the check ball mechanism occurs. Therefore, even when the engine brake is applied, the check ball mechanism does not slip, and the effectiveness of the engine brake does not deteriorate.

[Embodiments] Hereinafter, preferred embodiments of the low torsional stiffness split type flywheel according to the present invention will be described with reference to the drawings.

1 to 3 show the structure and characteristics of a flywheel according to a first embodiment of the present invention. As shown in the figure, the flywheels include a drive side flywheel 1, an intermediate flywheel 2,
It has a driven side flywheel 3, which are arranged on the same axis. A spring mechanism 4 extending in the circumferential direction of the flywheel is interposed between the drive-side flywheel 1 and the intermediate flywheel 2, and a check ball is provided between the intermediate flywheel 2 and the driven-side flywheel 3. A mechanism 5 and a one-way clutch 18 that transmits only negative torque but not positive torque are interposed.

Among the above, the drive side flywheel 1 is
It is fixed to the crankshaft 6 of the engine with a bolt 10 so that it rotates together.

The drive-side flywheel 1 includes outer and inner drive-side flywheel bodies 1a, 1.
b is sandwiched from both sides by a pair of side plates 1c and 1d and joined together by rivets 7.
A starter ring gear 8 is attached to the outer periphery of the drive-side flywheel 1 by press fit, shrink fit, or the like. Alternatively, the ring gear 8 itself may constitute the outer flywheel body 1a.

The driven flywheel 3 is made up of a driven flywheel main body 3a and a driven plate 3b integrally connected by bolts 9 in order to insert and hold the intermediate flywheel 2 therein. The driven flywheel 3 is rotatably supported by a bearing 11 on the drive flywheel main body 1b on the inner peripheral side of the drive flywheel 1.

The intermediate flywheel 2 is rotatably held by the driven flywheel 3 by a bearing 19. A hole 20 extending in the radial direction is provided on the outer peripheral surface of the driven plate 3b, and a hole 20 is provided in a circumferential direction of the inner peripheral surface of the intermediate flywheel 2.
A check ball engaging groove 15, which is a concave groove, is provided at a position corresponding to the hole 20 when the relative angular displacement (relative torsion angle) between the intermediate wheel 2 and the driven flywheel 3 is zero. The check ball engaging groove 15 extends short in the circumferential direction.
A check ball 13 is inserted into the hole 20 so as to be freely retractable, and is urged toward the check ball engagement groove 15 by a spring 17. The spring 17 releases the check ball engagement groove 15 when a certain amount of torque is applied to the flywheel.
The strength is set so that the check ball 13 shrinks and separates from the check ball engagement groove 15 due to the reaction force from the check ball 13 hitting the bank. That is, as shown in FIG. 3, when a constant positive torque T ₁ is applied, the drive-side flywheel 1 and the driven-side flywheel 3 contract by a constant torsion angle θ ₀ due to the spring mechanism 4, and then The check ball 13 and the check ball engagement groove 15 are disengaged, and the drive side flywheel 1 and the driven side flywheel 3 are twisted by more than θ ₀ , and the check ball 13 and the side surface of the driven side flywheel 3 slide with low friction. , the forward transmission torque is drastically reduced to T ₂ . The check ball 13, spring 17, and check ball engagement groove 15 constitute the check ball mechanism 5. For negative torque, the one-way clutch 18 prevents the check ball mechanism 5 from slipping;
The intermediate flywheel 2 and the driven flywheel 3 are designed to be locked.

The one-way clutch 18 and the check ball mechanism 5 are filled with oil to ensure smooth operation. When filling with oil, the oil must be sealed to prevent oil from leaking into the clutch, and the one-way clutch 18 and check ball mechanism 6 must be sealed with the oil seal 2.
1 from both sides.

Next, the operation of the low torsional stiffness split type flywheel of the first embodiment configured as described above will be explained.

Engine torque reaches the intermediate flywheel 2 from the crankshaft 6 through the drive-side flywheel 1, the low torsional rigidity spring mechanism 4. Torque transmission between the intermediate flywheel 2 and the driven flywheel 3 is performed via a check ball 13. The check ball 13 is pressed by a coil spring 17 into a check ball engagement groove 15 provided in a part of the inner circumference of the intermediate flywheel 2. A one-way clutch 18 is connected in parallel with the check ball 13 and has the characteristic of being free in the direction of positive torque and locking in the direction of negative torque.
connects the intermediate flywheel 2 and the driven flywheel 3.

During normal operation, positive torque is applied to the flywheel, and the check ball 13 is seated in the check ball engagement groove 15 and hits the bank 15a, transmitting engine torque to the driven flywheel 3.

Now, there is an abnormally large positive torque (T ₁ in Figure 3)
joins the flywheel, check ball 1
3 climbs over the bank 15a of the check ball engagement groove 15, causing a slip between the intermediate flywheel 2 and the driven flywheel 3, thereby preventing a large load from being applied to the spring mechanism 4. Spring 1
Since the pressing force of the check ball 13 by the check ball 7 is small, the torque at the time of slip (T ₂ in FIG. 3) is also small. Therefore, the sliding friction between the check ball 13 and the driven flywheel 3 is also reduced, and the generation of frictional heat can be reduced.

Furthermore, if negative torque is applied to the flywheel from the drive system during deceleration, the one-way clutch 1
8 locks the intermediate flywheel 2 and the driven flywheel 3, so that the engine brake can be reliably applied.

In addition, since the check ball 13 and the one-way clutch 18 are soaked in oil, the sliding friction force at the time of slipping is reduced and the effect of cooling frictional heat is enhanced. Further, the movement of the one-way clutch 18 becomes smoother, and the operation of the one-way clutch 18 can be made more reliable. The oil seal 21 is for sealing this oil.

FIG. 4 is related to the second embodiment of the present invention,
The check ball mechanism is shown. The second embodiment consists of the check ball engaging groove 15 of the first embodiment extended in the circumferential direction and left as a protrusion 22 including a bank 22a. As a result, when the intermediate flywheel 2 and the driven flywheel 3 are slipping, the spring 17 extends by the depth of the groove 15, so the force of the check ball 13 pushing the check ball engagement groove 15 is reduced. It is smaller than the first embodiment, and the frictional heat due to sliding is also further reduced. Other configurations and operations are the same as in the first embodiment, so corresponding parts are given the same reference numerals as in the first embodiment, and their explanations will be omitted.

[Effect of the invention] Therefore, when using the low torsional rigid split type flywheel of the present invention, a check ball mechanism is interposed between the intermediate flywheel and the driven side flywheel, and a one-way clutch is interposed, so that If a positive torque higher than the set torque is applied to the flywheel, the check ball rides on the bank of the check ball engagement groove, causing slippage between the intermediate flywheel and the driven flywheel, causing an excessive load to be applied to the spring mechanism. can be prevented, while maintaining the torque limiter mechanism.
Due to the light sliding of the check ball mechanism, sliding frictional heat can be reduced. Furthermore, when negative torque is applied, the one-way clutch operates to transmit even an abnormally large torque, so the effectiveness of the engine brake will not deteriorate.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a low torsional rigid split flywheel according to a first embodiment of the present invention, and FIG.
3 is a torsion angle-torsion torque characteristic diagram of the flywheel, and FIG. 4 is a sectional view of the check ball mechanism according to the second embodiment of the present invention. Figure 5 is a sectional view of a conventional two-part flywheel, Figure 6 is a vibration model diagram of the flywheel in Figure 5, and Figure 7 is a torsion angle-torsion torque characteristic diagram of the flywheel in Figure 5. be. 1... Drive side flywheel, 2... Intermediate flywheel, 3... Drive side flywheel, 4... Spring mechanism, 5... Check ball mechanism, 13... Check ball, 15... Check ball engagement groove , 17...Spring, 18...One-way clutch, 19...Bearing, 22...
…protrusion.

Claims (1)

[Scope of utility model registration request] A drive side flywheel, an intermediate flywheel, and a driven side flywheel are provided on the same axis, and the drive side flywheel and the intermediate flywheel are connected via a spring, and the intermediate flywheel and the driven side flywheel are connected to each other via a spring. A spring-biased check ball is provided on one side of the wheel and the driven flywheel, and a check ball engagement groove capable of receiving the check ball is provided on the other side of the wheel and the driven side flywheel, and the two are connected so as to be engageable and detachable via the check ball. A low torsional rigid split flywheel characterized by being connected via a one-way clutch that is installed in parallel with the check ball and transmits only negative torque.