JPS612966A - Fluid transmission device with variable torque transmission efficiency - Google Patents

Abstract

PURPOSE:To reduce variations in torque and enhance the economy of fuel consumption, by disposing an electrical viscofluid clutch which varies its transmission efficiency of torque. CONSTITUTION:Power transmitted from an engine to an input shaft 10, is transmitted to an output shaft 14 through a fluid transmission device 12. A fluid transmission device 12 comprises an electrical viscofluid clutch 16 and a torque converter 18. A flange 20 is formed at its end face of the input shaft 10. The output shaft 14 is disposed coaxially with the input shaft 10. A clutch disc 30 is incorporated in a chamber 27, and the transmission casing 22 is spaced apart from the clutch disc 30. An electrical viscofluid is filled in the chamber 27, and increases its viscous resistance under d.c. external electric field, that is, it has a characteristic exhibiting an electrical viscous effect as is called as WINTHROW effect. With this arrangement, when a voltage 30 is applied between slip rings 38, 40, the torque transmission efficiency may be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a fluid transmission device used in a vehicle that transmits power from an input shaft to an output shaft via fluid and can change torque transmission efficiency.

[Background Art] In a typical torque converter or fluid coupling, the torque transmission efficiency is determined by the speed ratio of the input shaft and the output shaft, and is not dependent on the presence or absence of torque fluctuation.

Therefore,]・High torque transmission efficiency】・When using a torque converter or a fluid coupling, the torque of the input shaft is efficiently transmitted to the output shaft, but the torque fluctuation of the output shaft is not reduced much. The space occupied by the torque converter and fluid coupling also increases. Conversely, if a shaft with low torque transmission efficiency is used in order to reduce the transmission of torque fluctuations from the output shaft, the fuel consumption rate of the power source connected to the input shaft will deteriorate.

Therefore, in order to reduce the transmission of torque fluctuations and improve fuel efficiency, a proposal was made to transmit power using magnetic powder and to control the l/lux transmission efficiency by changing the strength of the magnetic field. It's being served.

However, it is necessary to create a strong magnetic field, use a large coil, and require a large space.
It also increases costs.

In addition, the heat generated by slip and eddy waves is large, and a separate cooling device is required to cool it.

Furthermore, mM powder has magnetic hysteresis, which is not easy to control.

[Object of the Invention] Taking into account the above facts, the present invention is capable of achieving both reduction of torque fluctuation transmission and improvement of fuel efficiency, the structure can be downsized in the cylinder, cooling is easy, and control is possible. It is an object of the present invention to provide a fluid transmission device in which the torque transmission efficiency changes easily.

[Structure of the Invention] In the fluid transmission device according to the present invention in which the torque transmission efficiency can be changed, the input shaft and the output duck 11 are connected via an electrorheological fluid, and a voltage is applied to the electrorheological fluid to change the torque transmission efficiency. The 7L pneumatic fluid clutch has an electrorheological fluid clutch, and a torque converter or a fluid coupling that connects an input shaft and an output shaft via a tongue fluid disposed in parallel and coaxially with the 7L pneumatic fluid clutch.

[Embodiments of the Invention] An embodiment of a fluid transmission device in which torque transmission efficiency can be changed according to the present invention will be described with reference to the drawings.

As shown in FIG. 1, power transmitted from the engine to the input shaft 0 is transmitted to the output shaft 14 via a fluid transmission device 12.

The fluid transmission device 12 includes an electrorheological fluid clutch 16 and a torque converter 18. A flange 2o is provided on the end surface of the input shaft lO. A transmission case 22 is screwed onto the flange 20 with bolts 24. Facing the transmission case 22, a clutch cover 26 is welded at its edge to form a chamber 27.47.

The output shaft 14 is arranged coaxially with the input shaft 1o, and a flange 28 is provided on the end face facing the flange 2o. A clutch disk 30 is welded to the flange 28 with rivets 32.

The clutch disc 30 is contained in the chamber 27 and is spaced apart from the transmission case 22 and the clutch disc 3o. The chamber 27 is filled with electrorheological fluid. The electrorheological fluid 34 is a solid particle dispersion solution in which a dispersed phase such as A (OH) 3 coated aluminum particles is dispersed in a dispersion medium such as water or spindle oil. As shown in FIG. 2, an electrorheological fluid exhibits an electrorheological effect known as the so-called WINSLOW effect, in which viscous resistance increases with the strength of the electric field under a DC external electric field. Electrorheological + J1 fluid is also called electrorheological fluid, rAutomoti
ve Engineering November
1983J, rN published January 1984 161-1
It is also published in IKKEI MECHANICALJ. A hole 35 is provided in the center of the clutch cover 26, into which the input shaft 14 is fitted through a seal ring 36. Therefore, electrorheological fluid 34 is sealed into chamber 27 . Slip rings 38 and 40 are pressed into contact with the transmission case 22 and the output shaft 14, respectively, and the transmission case 22, the clutch cover 26, and the clutch disc 30
A voltage is applied to both. That is, an axial electric field is generated in the electrorheological fluid 34.

A vibrator 4 is installed in the center of a fixed base 42 that is fixed to the vehicle body.
4 is provided. This vibe 44 and transmission case 22
A hair ring metal 46 is interposed between the inner end surfaces of.

The torque converter 18 has a conventional structure. That is, the transmission case 22 and the clutch cover 26
In the chamber 47 formed by the turbine impeller 48
, a pump impeller 5o, and a stator impeller 52. The turbine impeller 48 is externally fitted onto the output shaft 14, so that when the turbine impeller 48 is rotated, the output shaft 14 rotates together. pump impeller 5
0 is provided on the inner surface of the transmission case 22 and is disposed facing the turbine impeller 48.

Further, the stator impeller 52 is attached to the vibrator 44 via a one-way clutch 54. Chamber 47 is filled with hydraulic oil 56.

Therefore, when the transmission case 22 rotates, the hydraulic oil 56 circulates as shown by the arrow in FIG. 1, and the power of the human power shaft 10 is transmitted to the output shaft 14 via the hydraulic oil 56.

When no voltage is applied between the slip rings 38 and 40, the viscosity of the electroviscous fluid 34 is sufficiently lower than the viscosity of the hydraulic oil 56, and the clutch disc 30 receives almost no viscous force from the electrorheological fluid 34. No, therefore
The torque transmission efficiency of the fluid transmission device 12 is equal to the j·lux transmission efficiency by the torque converter 18 alone.

Next, when a DC voltage is applied between the slip rings 38 and 40, the viscosity of the electrorheological fluid 34 becomes sufficiently thicker than the viscosity of the hydraulic oil 56, and the clutch disc 30 receives a large viscous force from the electrorheological fluid 34. . Therefore, the torque of the input shaft is transmitted to the output shaft 14 not only by the torque converter 18 but also by the electrorheological fluid clutch 16, and the torque transmission efficiency of the fluid transmission device 12 is increased.

From the above 1-, normal driving with little torque fluctuation 11 yen
By applying a voltage between the slip rings 38 and 40, the torque transmission efficiency of the fluid transmission bag P112 can be increased and fuel efficiency can be improved. Also,
When driving with large torque fluctuations, by not applying voltage between the slip rings 38 and 40, the torque transmission efficiency of the fluid transmission bag ff112 is reduced, and torque fluctuations of 0 on the input shaft are transmitted to the output shaft 14. It is possible to reduce the amount of

Note that the current that flows when a voltage is applied between the slip rings 38 and 40 is several milliamperes, and the power consumption of the electrorheological fluid clutch 16 is extremely small, so that an ordinary battery can be used. Furthermore, in order to increase the l-lux transmission efficiency of the electrorheological fluid clutch, the surface area may be increased by forming a plurality of chambers 27 or stacking a number of clutch disks 3o. Electrorheological fluid 3
The voltage applied to 4 differs depending on this surface area.

[Effects of the Invention] Changes in torque transmission efficiency according to the present invention 1! In this fluid transmission device, the two clutch discs 30 can be gradually locked by voltage control, and the shock caused by locking can be alleviated.

Since there is a forcedly cooled torque converter fluid in the surrounding area, there is no need for a dedicated cooling mechanism for electrorheological fluid.

Furthermore, by locking the clutch disc 3o even during acceleration, a feeling of acceleration that cannot be obtained with a conventional torque converter is improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a fluid transmission device with variable torque transmission efficiency according to the present invention, and FIG. 2 is a characteristic diagram of an electrorheological fluid. 10-Entry input shaft, 12...Fluid transmission device, 14φ...Output shaft, 16-...Electro-rheological fluid clutch, 18-Ya-torque converter, 30ψ-Fist clutch disc, 34-Fist-fist electro-rheological fluid. Figure 1

Claims (1)

[Claims] An electrorheological fluid clutch, in which an input shaft and an output shaft are connected via an electrorheological fluid, and a voltage is applied to the electrorheological fluid to change the torque transmission efficiency; 1. A fluid transmission device with variable torque transmission efficiency, comprising: a torque converter or a fluid coupling that connects an input shaft and an output shaft via a fluid transmission device.