JPH0492132A - Driving transmission - Google Patents

Abstract

PURPOSE:To avoid tight-corner-braking phenomenon during low differential operation and enable escape from a muddy spot during high differential operation by providing the first and second rotating members for the first and second space portions, a sub-room between the second piston and a shielding plate and an energizing member. CONSTITUTION:When the rotating speed of a differential between input and output shafts is in lower differential operation than a preset value, the first rotating member 26 and the second rotating member 51 are rotated relative to a housing 20, so that in the first space portion 25 high viscosity fluid 31a forcibly moves with the first blade 27 but flows out to a sub-room 42 through a through-hole 41 in a shielding plate 40 to cause pressure in the first space portion 25 to be restrained. When it comes to high differential rotation, the high viscosity fluid 31a thrusted by the second piston 44 flows from the sub-room 42 through the through-hole 41 in the shielding plate 40 into the first space portion 25 and increases in inner pressure so that the first piston 24 thrusts a clutch means 22 to transmit torque, which has caused pressure in the first space portion 25, between the input and output shafts in accordance with the rotating speed of the differential.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a driving force transmission device suitable for four-wheel drive vehicles and the like.

<Prior Art> An example of a conventional driving force transmission device is Japanese Patent Laid-Open No. 63-240429, which was previously filed by the present applicant. This publication describes a drive that transmits torque between two members by generating pressure in a space according to the relative rotational speed between two members, and by causing a sliding piston to press a clutch means due to the generated pressure. A force transmission device is disclosed.

A rotating member engaged with one of the two members is housed in the space. This rotating member generates pressure in the space by forcibly moving a high viscosity fluid sealed in the space in accordance with the relative rotational speed between the two members (hereinafter referred to as differential rotation speed). Further, the relationship between the transmission torque transmitted between the two members and the differential rotation speed is as shown by the solid line in FIG.

<Problems to be Solved by the Invention> In general, four-wheel drive vehicles have a problem with the tight corner braking phenomenon that tends to occur when the differential rotation speed is low when turning. In order to avoid this tight corner braking phenomenon, when the differential rotation speed is N00, the transmission torque between the input and output shafts should be set to below the predetermined value T0 shown in Fig. 7.On the other hand, when driving on a rough road, In order to escape from the mud, a transmission torque of a predetermined value of 10 or more is required.

However, in one device, the transmission torque T is less than or equal to the predetermined value T0. It is difficult to simultaneously satisfy both of the above transmission torques due to the relationship between the transmission torque and the differential rotation speed shown in FIG. 7 described above.

<Means for Solving the Problems> The present invention has been made in view of the above-mentioned conventional problems, and is composed of a housing connected to either one of the relatively rotatable input/output shafts, and a a clutch means housed in the input and output shafts for transmitting torque between the input and output shafts;
A first piston that controls the transmission torque of the clutch means, a first space provided on the side of the first piston and filled with a high viscosity fluid, and a difference between the input and output shafts housed in the first space. a first rotating member that forcibly moves the high viscosity fluid to generate pressure in the first space in response to dynamic rotation; A shielding plate having a plurality of through holes communicating with the first space, a slidable second piston facing the other side of the shielding plate, and a highly viscous fluid provided between the second piston and the housing. a second space enclosing;
a second rotating member that is housed in the second space and forcibly moves the high viscosity fluid to generate pressure in the second space according to the differential rotation of the input/output shaft; The piston includes a sub-chamber provided between the shielding plate and a high viscosity fluid retained therein, and a biasing member interposed between the second piston and the shielding plate.

<Function> With the above configuration, when a differential occurs between the relatively rotatable input and output shafts, and in the case of low differential where the differential rotation speed is less than a predetermined value, the differential rotation speed will be adjusted according to the differential rotation speed. The first rotating member and the second rotating member rotate relative to the housing. Second
In the space, pressure is generated by forced movement of the high viscosity fluid. The generated pressure causes the second piston to slide and press the clutch means via the biasing member.

The high viscosity fluid in the first space can flow out toward the subchamber through the through hole of the shielding plate, and the filling rate of the high viscosity fluid in the first space is low, and the generated pressure is extremely small.

Therefore, when the differential is low, torque is transmitted between the input and output shafts due to the pressure generated in the second space.

When the differential rotation speed between the two shafts reaches a high differential state that is equal to or higher than a predetermined value, the pressure generated in the second space increases according to this differential rotation speed, and the second piston It moves further toward the clutch means than the current position. As a result, the axial clearance in the second space increases, and the volume of the second space increases as a whole, so that the internal pressure in the second space decreases. On the other hand, the high viscosity fluid remaining in the subchamber passes through the through hole of the shielding plate and flows into the first space due to the pressing force from the second piston. As this high-viscosity fluid flows in, the filling rate of the high-viscosity fluid increases in the first space, so the pressure generated in the first space increases compared to when the differential is low.

This generated pressure causes the first piston to slide and press the clutch means.

Therefore, when the differential is high, torque is transmitted between the input and output shafts due to the pressure generated in the first space.

Therefore, when the differential is low, torque is transmitted between the input and output shafts due to the pressure generated in the second space where the transmission torque is set low, so that the tight corner braking phenomenon is avoided.

In addition, during high differential operation, the filling rate of high viscosity fluid increases in the first space as the differential rotates, and torque is transmitted due to the pressure generated in the first space, resulting in a high transmitted torque. , it becomes possible to escape from the mud.

<Example> Embodiments of the present invention will be described below based on the drawings.

In FIG. 3, 10 is an engine, 11 is a transmission, 13 is a front wheel differential, 14 is a drive shaft, 15 is a front wheel, 16 is a rear wheel differential, and 17 is a rear wheel. The driving force transmission device 1 is an input shaft 1 of a drive shaft 14.
4a and the output shaft 14b.

The torque from the engine 10 is transmitted to the transmission 11
The power is transmitted to the front wheel differential device 13 to drive the front wheels 15 , and is also transmitted to the drive shaft 14 and transmitted to the rear wheels 17 via the drive force transmission device 1 and the rear wheel differential device 16 .

The specific configuration of the driving force transmission device 1 will be described below.

In FIG. 1, reference numeral 20 indicates a housing connected to the input shaft 14a, and the housing 20 has a cylindrical shape with a bottom.
is attached to form a hollow chamber. End cap 21
A rotary shaft 14c is rotatably supported on the rotary shaft 14c, and this rotary shaft 14c is connected to the output shaft 14b.

A clutch means 22 is housed in the housing 20, and this clutch means 22 is connected to an outer plate 22.
a and inner plates 22b are arranged alternately, the outer plate 22a is spline engaged with the inner circumference of the housing 20, and the inner plate 22b is spline engaged with a clutch hub 23 provided on the outer circumference of the rotating shaft 14c. has been done.

A first piston 24 is slidably fitted on the side of the clutch means 22. 25 is a cylindrical first space having the end wall 24a of the first piston 24 on one side, and a first rotating member 26 having a wall thickness slightly smaller than the axial dimension of the first space 25 is provided in the first space 25. is housed in a slidable manner. The first rotating member 26 has its center connected to the output shaft 14.
It is spline engaged with the outer periphery of b. First rotating member 2
6 generates pressure according to the differential rotation speed between the housing 20 connected to the input shaft 14a and the output shaft 14b, as will be described later.

The first rotating member 26 has two first blades 27 extending in the diametrical direction as shown in FIG.
It is divided into 0. Each of these pressure chambers 30 is filled with a high viscosity fluid 31a such as silicone oil and several percent of air. When the output shaft 14b and the housing 20 rotate relative to each other, the high viscosity fluid 31a filled in the pressure chamber 30 is forcibly moved between the two surfaces by the first blade 27 at a flow rate corresponding to the rotational speed difference. Note that the internal pressure of the first space 25 increases in proportion to the amount of forced movement of the high viscosity fluid 31a. Further, the internal pressure of the first space 25 increases in proportion to the filling rate of the high viscosity fluid 31a.

Note that the characteristic curve of transmission torque versus differential rotation speed due to the pressure generated in the first space 250 is set as shown by line A in FIG. 5.

Reference numeral 40 denotes a shielding plate disposed on the side of the first space 25 in the axial direction. This shielding plate 40 is donut-shaped with a hole in the center and is movable in the axial direction.
As shown in FIG. 3, a plurality of through holes 41 passing through in the axial direction are formed on the circumference. This through hole 41 allows the first
The space 25 and a subchamber 42, which will be described later, are in communication. The sub-chamber 42 is a cylindrical gap extending in the axial direction, and the high-viscosity fluid 31a always stays therein.

44 is a second piston arranged on the side of the subchamber 42, and this second piston 44 is slidably fitted into the housing 20.

The second piston 44 has a hole 44 opened to the shielding plate 40 side.
A plurality of a are provided on the circumference. One end of a biasing member (spring) 45 having a high spring constant is in close contact with the bottom of the hole 44a, and the other end of the biasing member 45 is connected to one wall 40a of the shielding plate 40 facing the second piston 44. installed on. Further, the biasing member 45 always presses the shielding plate 40 with a constant pressure.

The shielding plate 40 is supported by a plurality of biasing members 45. When differential rotation is not occurring, the outer peripheral end of the shielding plate 40 is in contact with the stepped portion 20a of the housing 20,
The axial clearance of the first space is kept constant.

A cylindrical second space 50 is provided between the second piston 44 and the end cover 21, and the second space 50 has a second space 50 with a wall thickness slightly smaller than its axial dimension. A two-rotation member 51 is rotatably housed. The second rotating member 51 has its center portion spline-engaged with the outer periphery of the output shaft 14b.

The second rotating member 51 includes two second rotating members extending in the diametrical direction.
It has a blade 52. Further, the second space portion 50 is circumferentially partitioned into two pressure chambers 53 by the second blade 52 . The pressure chamber 53 is filled with a high viscosity fluid 31b such as silicone oil and several percent of air. The mechanism for generating internal pressure in the second space 50 is the same as that in the first space 25 described above, and the relationship between the transmitted torque and the differential rotation speed in the second space 50 is based on the two points in FIG. It is set as shown by chain line B.

Further, the thickness of the second blade 52 in the axial direction is smaller than the thickness of the first blade 27 in the axial direction. Therefore, compared to the first space 25, the rate of change in volume of the second space 50 is small, and even if the second piston 44 slides a predetermined amount, the pressure generated in the second space 50 does not fluctuate much.

Next, the operation of the driving force transmission device 1 with the above configuration will be explained.

Differential rotation occurs between the input shaft 14a and the output shaft 14b,
In the case of a low differential where this differential rotation speed is less than the predetermined value N0, the first
The rotating member 26 and the second rotating member 51 rotate relative to the housing 20. In the second space 50, pressure is generated according to the forced movement of the high viscosity fluid 31b by the second blade 52, and the second piston 44 slides due to this pressure. The pressing force of the second piston 44 is then applied to the urging member 45.
, acts on the clutch means 22 through the shielding plate 40.

In the first space 25, the high viscosity fluid 31a is forcibly moved by the first blade 27. However, since the high viscosity fluid 31a passes through the through hole 41 of the shielding plate 40 and flows out toward the auxiliary chamber 42, the pressure generated in the first space 25 is suppressed.

Therefore, at the time of low differential, the torque caused by the pressure generated in the second space 50 is applied to the input/output shaft 14a,
14b.

Next, the differential rotation speed of the input and output shafts 14a and 14b is set to a predetermined value N.
When a high differential rotation state of 0 or more is reached, the internal pressure in the second space 50 further increases in accordance with this differential rotation speed, and the second piston 44 further slides toward the clutch means 22 side. At this time, the axial clearance of the second space 50 increases, so the pressure generated in the second space 50 begins to decrease.

On the other hand, the high viscosity fluid 31a pressed by the second piston 44
flows from the subchamber 42 into the first space 25 through the through hole 41 of the shielding plate 40 . As this high-viscosity fluid 31a flows in, the filling rate increases in the first space 25, and the internal pressure increases.

The first piston 24, which slides due to this internal pressure, presses the clutch means 22.

Therefore, at the time of high differential, the torque caused by the pressure generated in the first space 25 is transmitted between the input and output shafts 14a and 14b according to the differential rotation speed.

Therefore, the characteristic curve of transmission torque versus differential rotation speed becomes as shown by the solid line C in FIG. At the time of low differential below the predetermined value N0,
Since the transmitted torque is less than T0, no tight corner braking phenomenon occurs, and when the differential is higher than the predetermined value N0, the transmitted torque is more than T0, making it possible to escape from the mud when stuck.

Further, in this embodiment, the shielding plate 40 is movable in the axial direction, but by fixing this shielding plate and simply increasing or decreasing the filling rate of the high-viscosity fluid 31a in the first space 25, the input/output axis can be moved. It is also possible to vary the transmission torque between 14a and 14b.

Note that the first rotating member 26, the second rotating member 51, and the first
The shapes of the blade 27 and the second blade 52 are not limited to those of this embodiment.

<Effects of the Invention> As described above, according to the present invention, it is possible to vary the relationship between the transmitted torque and the differential rotation speed with one device.

For example, when the differential is low, the high viscosity fluid in the first space flows out into the subchamber through the through hole of the shielding plate, so the pressure generated in the first space is suppressed. Therefore, the torque transmitted between the input and output shafts is controlled by the pressure generated in the second space. Therefore, the torque based on the relationship between the transmission torque of the second space and the differential rotation speed is transmitted between the input and output shafts, so that the tight corner braking phenomenon is avoided.

When the differential is high, as the second piston slides, the axial clearance increases in the second space, so the pressure generated in the second space is suppressed. Therefore, the torque transmitted between the input and output shafts is controlled by the pressure generated in the first space. Therefore, a torque based on the relationship between the transmission torque of the first space and the differential rotation speed is transmitted between the input and output shafts, so that it is possible to escape from the mud when stuck.

[Brief explanation of drawings]

The drawings show this embodiment, and FIG. 1 is a diagram showing the driving force transmission device of the present invention, FIG. 2 is a sectional view taken along ■-■ in FIG. 1, and FIG. 3 is a cross-sectional view taken along ■-■ in FIG. The sectional view, FIG. 4, is IV- in FIG. 1.
IV sectional view, FIG. 5 is an overall view of the vehicle, FIG. 6 is a diagram showing the relationship between the transmitted torque and differential rotation speed of the present invention, and FIG. 7 is a diagram showing the relationship between the conventional transmission torque and differential rotation speed. It is a diagram showing the relationship. Engineering: Drive force transmission device, 14... Drive shaft, 14...
・Drive shaft, 14a...input shaft, 14b...output shaft,
20... Housing, 22... Clutch means, 24
...first piston, 25...first space, 26...
-First rotating member, 27...first blade, 31a...
- High viscosity fluid, 31b... High viscosity fluid, 40... Shielding plate, 4■... Through hole, 42... Sub-chamber, 44...
2nd piston, 45... urging member, 50... 2nd space part, 51... 2nd rotating member, 52... 2nd blade.

Claims (1)

[Claims] (1) A housing connected to either one of the relatively rotatable input/output shafts, a clutch means housed within the housing and transmitting torque between the input/output shafts, and controlling the transmitted torque of the clutch means. a first piston; a first space provided on the side of the first piston and enclosing a high viscosity fluid; a first rotating member that forcibly moves to generate pressure in the first space; and a through hole that faces the first piston on one side and communicates with the first space to house the first rotating member. a second sliding piston facing the other side of the shielding plate; a second space provided between the second piston and the housing and enclosing a high viscosity fluid; This second
a second rotating member that is housed in a space and forcibly moves the high viscosity fluid in response to differential rotation of the input and output shafts to generate pressure in the second space; the second piston and the shielding plate; a driving force transmission device comprising: a sub-chamber in which a high-viscosity fluid is retained and communicated with the first space; and a biasing member interposed between the second piston and the shielding plate; .