JPH026286Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a power transmission mechanism for an automobile, and particularly to a power transmission mechanism from engine output to transmission input.

[Conventional technology]

In order to absorb engine torque fluctuations, a structure has been proposed in which a flywheel, which is a mass body in a power transmission mechanism, is divided into two parts and the two parts are connected by an elastic body. However, if the resonance frequency determined by the inertial mass of the flywheel, which is divided into two parts, and the spring constant of the elastic body that connects the flywheel, is near the vibration frequency of the engine when it is idling, the engine will not transmit the transmission. There is a problem in that this causes resonance in the power transmission system leading to the engine, causing unpleasant vibrations and, in some cases, phenomena such as engine stoppage. As a two-part flywheel equipped with a clutch mechanism, Japanese Patent Publication No. 57-17224,
Japanese Utility Model Application Publication No. 57-94740 and Japanese Patent Application Publication No. 55-132438 disclose a so-called variable inertial mass type two-part flywheel that stabilizes rotation by changing the inertial mass. However, since a variable inertia flywheel does not have a spring, there is no resonance point.

[The problem that the idea aims to solve]

However, the two-split flywheel of the variable inertial mass type has a problem in that it is accompanied by a shock when the inertial mass changes.

The present invention connects two mass bodies with a spring, and therefore prevents resonance in a two-part flywheel having a resonance point without changing the inertial mass, that is, the inertial mass remains constant. Another purpose is to provide a torque fluctuation absorbing power transmission mechanism that makes it possible to smoothly avoid resonance by adding a wet friction clutch mechanism to a connection path including a spring that connects two inertial masses and controlling the slippage of the clutch mechanism. shall be.

[Means to solve the problem]

In order to achieve this objective, the torque fluctuation absorbing power transmission mechanism of the present invention includes at least two mass bodies (flywheels) arranged in series in the vehicle power transmission system from the engine output to the transmission input. These masses are connected by a vibration-absorbing elastic body having a wet friction clutch mechanism at one end, and the wet friction clutch mechanism is provided with means for controlling the friction contact force. The means for controlling the frictional contact force receives signals such as an engine rotational speed signal, a throttle opening signal, a transmission rotational speed signal, a transmission shift signal, a brake signal, etc., and controls the engine and transmission. Output an output signal that matches the actual slip rotation speed with the pre-stored slip rotation speed corresponding to each of the signals.
CPU (computer central processing unit) and the CPU
and a hydraulic control unit that receives signals from the wet friction clutch mechanism and controls hydraulic pressure that is supplied to the wet friction clutch mechanism and changes the clutch pressing force of the wet friction clutch mechanism.

[Effect]

In a power transmission mechanism including at least two mass bodies in which the frictional contact force of the clutch is controlled by the CPU, the engine speed is
When it approaches the resonance frequency of the vibration system determined by the mass body and the elastic body that connects the mass body when turned on, the clutch mechanism is slid to lower the rotation speed of the mass body on the power train side slightly below the engine rotation speed. This makes it possible to avoid a rotational speed that is likely to cause resonance, thereby making it possible to prevent the resonance phenomenon from occurring. In addition, by utilizing this slippage, it is possible to always transmit rotation with sufficiently small torque fluctuations to the transmission, thereby reducing muffled noise in the passenger compartment and improving the ride comfort of the vehicle. Can be done. Since this resonance prevention mechanism has a constant inertial mass and does not change the inertial mass, no shock occurs.

〔Example〕

Hereinafter, preferred embodiments of the torque fluctuation absorbing power transmission mechanism of the present invention will be described with reference to the drawings.

1 to 3 show the principle of the power transmission mechanism according to the present invention. In these figures, C
is the engine crankshaft, I1 and I2 are mass bodies (flywheels), K is an elastic body, and T is a transmission. Figure 1 shows two mass bodies (flywheels) I1 and I in the rotary power transmission system from the engine output to the transmission input.
2 are arranged in series and are connected by an elastic body (elastomer) K having a clutch at one end. Furthermore, FIGS. 2 and 3 show that a clutch may be provided at either end of the elastic body K. That is, in FIG. 2, a clutch is provided at the front end of the elastic body K, and the mass body I
1 is divided into I1' and I1'', and in FIG. 3, a clutch is provided at the rear end of the elastic body K, and the mass body I
2 is divided into I2' and I2''.

FIG. 4 shows an embodiment of a power transmission mechanism embodying the principle shown in FIG. The components of this power transmission mechanism are divided into three mass body groups corresponding to I1', I1'', and I2, and will be explained in order.

First, the configuration of the engine side mass body group corresponding to I1' will be explained. There is a flywheel bolt 1 on the output side of the engine crankshaft 15.
A drive plate 1 is attached by 4, and a ring gear 7 is fitted into the drive plate 1. Further, a front case 2 is attached to the drive plate 1 with bolts 16 and is integrated therewith. A rear case 2' is welded to the front case 2, and these cases 2 and 2' maintain airtightness except for oil passages a and b.

Inside the cases 2 and 2', there are built-in mass body groups corresponding to I1'' and I2.
As a clutch side mass body group corresponding to 1″,
The power is turned on and off by pressing and releasing the clutch facing 6 against the inner surface of the case 2 using hydraulic pressure.
A pressure plate 5 that performs this, a guide plate 4 that serves as a guide when the pressure plate 5 slides back and forth (in the axial direction) to turn the power ON and OFF, and is integrated with the guide plate 4. There is a disc plate 3 and a sun gear 10, which are shaped like a disc plate 3 and a sun gear 10. The relationship between the disc plate 3 and the pressure plate 5 is that they are combined by gear-shaped notches 3' and 5' provided at the outermost periphery of each, and the pressure plate 5 rotates relative to the disc plate 3. The structure is such that it is always fixed in one direction, but can move freely in the front-back direction (axial direction).

Next, as a transmission side mass body group corresponding to I2, there is a flange 17 having a spline 17' that fits with the spline 13' of the input shaft 13 of the transmission, and a driven plate 18 that is integrated with the flange 17. , an additional weight 12, and a deflection link gear 11.

Each mass body group corresponding to I1', I1'', and I2 constitutes an integral mass body at least in the rotational direction.Mass body I1''
and I2 are connected by an elastic body K, and the structure corresponding to this elastic body K is as follows.

Sun gear 10 on mass group I1, I1″ side
As shown in FIGS. 4 and 5, a plurality of planetary gears 9, for example, six planetary gears 9, are arranged between the mass group I2 and the mass group I2 side, and one planetary gear 9 is arranged around the eccentric shaft 9' of each planetary gear 9. An elastic belt 8 is wound around the elastic belt 8 with an initial tension applied thereto. The elastic belt 8 is made of elastomer such as synthetic rubber,
It constitutes an elastic body K for vibration absorption that connects mass body groups I1'' and I2.

Incidentally, the insides of the cases 2 and 2' are filled with oil for the purpose of reducing gear noise, lubricating, and operating the wet clutch. This oil is supplied into the cases 2, 2' from oil passages a, b, and the pressure plate 5 of the hydraulic friction clutch is operated by the oil pressure. That is, assuming that the oil pressures in the oil passages a and b are Pa and Pb, respectively, the oil pressure Pa passes through the bearing 20 that supports the flange 17 and acts on the right side surface of the pressure plate 5 from inside the case portion 2'. , while the hydraulic pressure Pb acts on the left side surface of the pressure plate 5 through passages 21 and 22 in the input shaft 13 of the transmission.

Next, the operation of the power transmission mechanism shown in FIG. 4 will be explained. First, when the engine power is not transmitted to the transmission or later (that is, the clutch is OFF), the oil pressure Pa in the oil passage a is
This can be obtained by setting the relationship between and the hydraulic pressure Pa of the oil passage b section as Pa<Pb. That is, in this state, the pressure plate 5 is pressed against the disk plate 3 due to the oil pressure difference, and the clutch facing 6 is separated from the case 2, so that the engine power is not transmitted to the input shaft 13 of the transmission.

The state in which engine power is transmitted to the transmission and subsequent parts (that is, the clutch ON state) is obtained by setting the oil pressure so that Pa>Pb. In this state, due to the oil pressure difference, the gear-shaped notch 5' on the outer periphery of the pressure plate 5 is pushed against the disc plate 3.
The clutch facing 6 is pressed against the case 2 while still being engaged with the gear-like notch 3', and becomes integrated with the case 2. As a result, power is transmitted from the engine crankshaft 15 to the drive plate 1 and the case 2 (the above are mass group I
1'), pressure plate 5, disk plate 3, guide plate 4, sun gear 10 (the above are mass body group I1''), planetary gear 9 (elastic body), ring gear 11, driven plate 18,
It is transmitted in this order to the flange 17 and then to the input shaft 13 of the transmission (these are mass group I2).

In the above power transmission mechanism, the sun gear 10 and the ring gear 11 are elastically coupled by a planetary gear 9 wrapped around an elastic belt 8 as shown in FIG. is absorbed in this part, making it difficult for it to be transmitted to the transmission side. That is, as shown in FIG. 2, the plurality of planetary gears 9 have elastic belts 8 given an initial tension wrapped around their eccentric shafts 9', so that each planetary gear 9 has its eccentric shafts 9'' are positioned on the side of a common central axis (FIG. 5). In this state, when the rotational force is transmitted from the sun gear 10 to the ring gear 11, the sun gear 10
When there is a rotational torque fluctuation on the (engine) side, each planetary gear 9 rotates slightly against the elastic belt 8, thereby absorbing the torque fluctuation portion.
It is difficult to transmit to ring gear 11 (transmission side).

However, if the torsional spring constant due to the elastic body 8 wound around the planetary gear 9 is K, then
The natural frequency f of the vibration system consisting of mass groups I1 and I2 and K is f = {K (I1 + I2) / (I1, I2)} x 1/2 π, and the fluctuation frequency of the engine is close to this frequency f. When it gets old, it tends to resonate and cause abnormal vibrations. Under such circumstances, oil passage a,
By appropriately controlling the hydraulic pressure applied to b and allowing the pressure plate 5 to slide with respect to the rotation of the case 2, undesirable resonance phenomena can be avoided.

FIG. 6 shows the hydraulic control method of the hydraulic friction clutch according to the present invention. In the figure, E/G is an engine, T/M is a transmission, 30 is a hydraulic friction clutch, 31 is a CPU, and 32 is a pressure control unit. As shown in the figure, the CPU 31 receives an engine rotational speed signal Ne, a throttle opening signal φ, a transmission rotational speed signal Ne, a transmission shift signal HSe, and a brake signal Sb. The CPU 31 compares the slip rotation speed, which is the difference between the engine rotation speed and the transmission rotation speed, with a preset and stored "slip rotation speed map" and outputs each of the signals Ne, φ, Ne, Ss, A signal that compares the target slip rotation speed corresponding to Sb and matches the actual slip rotation speed with the value set in advance on the map.
Sr is output to the hydraulic control unit 32 to drive the hydraulic control unit 32. The hydraulic control unit 32 controls the hydraulic pressures Pa and Pb of the oil passages a and b (Fig. 4) according to the output signal from the CPU 31 to automatically turn the clutch ON and OFF, and also to automatically turn the clutch ON and OFF. As mentioned above, the torque fluctuation frequency depending on the engine speed is the mass group I1,
When the state approaches the natural frequency f of the system consisting of I2 and spring constant K, the oil pressure Pa in oil passages a and b,
By appropriately controlling Pb and slightly slipping the pressure plate 5 with respect to the rotation of the case 2, the rotational speed of the mass body groups I1'' and I2 is made slightly lower than the engine rotational speed. Avoid rotational speeds that are likely to cause resonance phenomena.

FIG. 7 is a block diagram showing the control mechanism of the CPU 31 in more detail.

The circuit configuration in the figure will be explained.

A subtracter 33 separates the engine rotational speed signal Ne and the transmission input shaft rotational speed signal Ne.
The ideal slip rate determination circuit 34 calculates and outputs the difference Nd between
This is a circuit that calculates and outputs Ni. Comparator 35
is a circuit for comparing Nd and Ni and sending a clutch hydraulic pressure increase/decrease command signal Sr to the hydraulic valve control circuit 39. In addition, Ne is also input to the comparator 37, which compares Ne with the minimum allowable engine rotation speed (preferably set slightly higher than the idle rotation speed) and determines that Ne≦Nl. Time,
Outputs the signal HSx. Note that Nl may be stored in the Nl storage unit 36, or may be set each time based on various conditions by providing another CPU.
This output signal is input to the AND circuit 38 together with the brake signal Sb which turns ON when the brake is depressed. The output signal Sy from the AND circuit is input to the OR circuit 40 together with the transmission shift signal Ss which turns ON when the driver touches the shift knob. When either Sy or Ss is ON,
Signal from OR circuit 40 to hydraulic valve control circuit 39
Sz is sent to command the action of disengaging the hydraulic clutch 30. However, when Sz returned to OFF,
The hydraulic pressure command signal Sr output from the hydraulic control circuit 39 to the hydraulic valve changes gradually, and is designed to reduce shock during clutch engagement.

[Effect of idea]

As explained above, in the torque fluctuation absorbing power transmission mechanism of the present invention, two mass bodies are connected by a vibration absorbing elastic body provided with a wet friction clutch mechanism at one end, and the clutch is turned on and off. The slip rotation speed is controlled by a CPU that operates according to the engine rotation speed and an output signal, and a hydraulic control unit that changes the pressing force of the wet friction clutch mechanism in response to the signal from the CPU. For example, it is possible to accurately catch the possibility of resonance between the vibration system consisting of a split flywheel and a spring and the engine rotation, and when there is a risk of resonance, the clutch applies slip between the flywheels and prevents the power train from resonating. The rotational speed of the connected mass body can be lowered than the engine rotational speed to be removed from the rotational speed at which resonance is likely to occur, and resonance can be reliably avoided. Moreover, since the inertial mass is constant and resonance is prevented by the infinitely controllable slip of the clutch, there is no occurrence of shocks that occur in variable inertial mass type torque fluctuation absorbing flywheels.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are connection relationship diagrams of each component showing the principle of the power transmission mechanism of the present invention, and Figure 4 is a diagram of the power transmission mechanism of the present invention equipped with a hydraulic friction clutch. 5 is a schematic sectional view taken along the - line in FIG. 4, FIG. 6 is a hydraulic control system diagram of the hydraulic friction clutch of the present invention, and FIG. 7 is a diagram of the CPU shown in FIG. 6. FIG. 3 is a block diagram showing the mechanism. I1I1', I1'', I2I2', I2''...Mass body, C...Crankshaft, T, T/M...Transmission, E/G...Engine, K...
Elastic body, 8...Elastic belt, 31...CPU, 3
2... Hydraulic control unit, 33... Engine rotation speed signal, 34... Throttle opening signal, 35...
Transmission rotation speed signal, 36... Transmission shift signal, 37... Brake signal.

Claims (1)

[Scope of utility model registration request] At least two mass bodies I1 and I2 are arranged in series in the power transmission system of the automobile from the engine output to the transmission input, and these mass bodies are connected to a vibration-absorbing elastic clutch having a wet friction clutch mechanism at one end. In the torque fluctuation absorbing power transmission mechanism, the wet friction clutch mechanism is connected by a body K and is provided with a means for controlling frictional contact force. , a transmission rotation speed signal, a transmission shift signal, and a brake signal are received, and the slip rotation speeds of the engine and transmission are stored in advance, and an output signal is generated to match the slip rotation speed corresponding to each of the signals. Torque variation characterized by comprising: a CPU for outputting the output; and a hydraulic control unit that receives a signal from the CPU and controls hydraulic pressure that is supplied to the wet friction clutch mechanism and changes the clutch pressing force of the wet friction clutch mechanism. Absorption power transmission mechanism.