JP2620314B2 - Driving force transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a driving force transmission device that transmits rotational power between two relatively rotatable shafts when differential rotation occurs between the two shafts. It is about.

<Related Art> In a torque transmission device for a four-wheel drive vehicle, torque is transmitted between a front wheel drive shaft (input shaft) and a rear wheel drive shaft (output shaft) between the two shafts in a sealed chamber formed between the two shafts. A multi-plate clutch is disposed, and an operating piston for controlling a transmission torque of the multi-plate clutch by hydraulic pressure of hydraulic pressure generating means for generating a hydraulic pressure according to a differential rotation between the front wheel drive shaft and the rear wheel drive shaft is provided. A driving force transmitting device is known, for example, from Japanese Patent Application Laid-Open No. Sho 60-252026.

However, the hydraulic pressure generating means incorporates a plunger type or vane type oil pump between the front wheel drive shaft and the rear wheel drive shaft, which generates hydraulic pressure according to the operation rotation of both shafts. The discharged pressure oil is introduced into a cylinder chamber on one side of the working piston via a pressure introduction passage formed on one of the two shafts, and the multi-plate clutch is pressed in the joining direction by the working piston.

Further, as the hydraulic pressure generating means, an axial gap limited between the working piston and the cylinder housing is provided on the side of the working piston, and the axial gap has a thickness substantially equal to that of the gap. A thin rotor is housed, this rotor is connected to one of the front wheel drive shaft and the rear wheel drive shaft, and the other is connected to the cylinder housing, and a plurality of blades are provided on the circumference of the rotor. The above-mentioned space is divided into a plurality of parts on a circumference by a blade, and a high-viscosity oil is sealed in each of these spaces, which is provided by the applicant of the present invention in Japanese Patent Application No. 62-75240.

<Problems to be Solved by the Invention> However, in the torque transmission device as disclosed in Japanese Patent Application Laid-Open No. 60-252026, it is necessary to incorporate an oil pump between the two shafts. It is necessary to form a passage for introducing a hydraulic clutch, and the configuration becomes complicated, and there is a problem that the size is large and the cost is high.

Such a problem is solved in the above-mentioned Japanese Patent Application Laid-Open No. 62-75240.

By the way, in this type of torque transmission device, when the differential rotation is not occurring, the backlash is generated in the clutch portion. Therefore, the backlash is adjusted by interposing a spacer ring between the clutch plates. However, when a spacer ring is interposed, a differential rotation occurs, and a large time lag occurs before the clutch is engaged, resulting in poor responsiveness. Therefore, unlike a four-wheel drive vehicle, there is a problem that a sudden rise of a special torque transmission that requires four-wheel drive at the time of escape from a rough road cannot be obtained.

Therefore, the present invention can be realized by employing a specific hydraulic pressure generating means described in Japanese Patent Application No. 62-75240.
An object of the present invention is to improve the responsiveness of a sufficient loosening of torque transmission at the time of occurrence of differential rotation without rattling of the clutch means without using the spacer ring.

<Means for Solving the Problems> According to a configuration of the present invention for achieving the above object, a clutch means disposed between two relatively rotatable shafts and transmitting torque between the two shafts, and the clutch means A driving force transmission device having an operating piston for controlling transmission torque of
A space is provided on the side of the working piston between the working piston and the cylinder housing, the rotor is housed in the space, the rotor is connected to one of the two shafts, and the other is connected to the other. A cylinder housing is connected, a plurality of blades are provided on the circumference of the rotor, and the blades divide the space into a plurality of circumferences. The working piston is held in a pre-pressed state in which the working piston slightly presses in the direction in which the clutch means is joined in a state in which working rotation does not occur between the two shafts in the space enclosing the body.

<Operation> With the above configuration, when the two shafts rotate differentially and the rotor rotates in the cylinder housing, the high-viscosity fluid sealed in the space defined by the blades of the rotor forcibly moves in the space. As a result, due to the viscous friction effect, the high-viscosity fluid in the space increases in pressure according to the differential rotation speed, presses the working piston, connects the clutch means, and transmits torque between the two shafts.

By the way, the interior of the space where the high-viscosity fluid is sealed maintains a pre-compressed state. Therefore, when the two shafts are not rotating differentially, the preload causes the differential piston to be in a pressed state in which the clutch means is slightly joined, thereby performing the play of the clutch means. In addition, when differential rotation occurs, a quick rise torque transmission is obtained.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings. First
In the figure, reference numeral 30 denotes a driving force transmission device. 32 is a cylinder housing to which one end of the input shaft is connected. 31 indicates a housing cap, which is
The inside of 32 is sealed. A rotation shaft 33 is rotatably supported on the cylinder housing 32 and the housing cap 31 concentrically with the cylinder housing 32. One end of an output shaft is connected to the rotating shaft 33.

In the cylinder housing 32, a clutch lubricating oil is sealed, and a plurality of outer plates 37 are engaged with the inner periphery of the cylinder housing 32 by splines in the rotational direction, and are juxtaposed to be movable in the axial direction. Have been.

On the other hand, a plurality of inner plates 38 are arranged on the outer periphery of the rotating shaft 33 so as to be engaged with each other by splines in the rotating direction and to be movable in the axial direction. The outer plate 37 and the inner plate 38 are alternately arranged to form a multi-plate clutch 40 as clutch means. In the cylinder housing 32, an operating piston 36 is slidably fitted between the other-plate clutch 40 and the cylinder housing 32, and the operating force of the operating piston 36 is transmitted to the multi-plate clutch 40.

On the side of the working piston 36, a cylinder housing is provided.
A space 43 formed of an axial gap is provided between the rotor 41 and the space 32. A rotor 41 having substantially the same thickness as the space 43 is slidably accommodated in the space 43 formed of the axial gap. A blade 42 is formed on the rotor 41 in the diameter direction as shown in FIG.

The rotor 41 has a central portion spline-engaged with the outer periphery of the rotation shaft 33, and is rotatable relative to the cylinder housing 32. Note that the rotor 41 may be spline-engaged on the outer periphery with the inner periphery of the cylinder housing 32 so as to be rotatable relative to the rotation shaft 33. With these, a space portion 43 formed by an axial gap is circumferentially partitioned by the plurality of blades 42, and a high-viscosity fluid such as silicone oil is sealed in these space portions 44 and 45.

As means for enclosing the high-viscosity fluid in these spaces 44, 45, an inlet 50 communicating with the spaces 44, 45 is provided in the cylinder housing 32, and a plug bolt 51 is screwed into the inlet 50. Is suitable.

The spaces 44 and 45 in which the high-viscosity fluid is sealed are set in a pre-pressurized state, and the state in which the working piston 36 is slightly pressed in the direction in which the multi-plate clutch 40 is joined is maintained.

This preload is applied by injecting a slightly higher-viscosity fluid than the normal injection amount according to the volume of the space portions 44 and 45 (calculated by design or actual measurement) from the injection port 50, and the plug bolt 51 is removed. Obtained by tightening.

With the above configuration, the cylinder housing 32 and the rotating shaft
When the differential rotation of the cylinder 33 is performed, the high-viscosity fluid sealed in the space 43 is forcibly moved by the blade 42 at a flow rate corresponding to the rotational speed difference between the two adjacent surfaces.
And internal pressure is generated by viscous friction with both end surfaces of the working piston 36. That is, for example, when the rotor 41 rotates clockwise with respect to the cylinder housing 32 in FIG. 2, an internal pressure having a high pressure distribution on the A1, A2 surface of the blade 42 and a low pressure distribution on the B1, B2 surface of the blade 42 is generated. This internal pressure causes the working piston 36 to be pressed in the direction in which the multi-plate clutch 40 is pressed, thereby performing a torque transmitting action.

When the cylinder housing 32 and the rotating shaft 33 do not rotate differentially, the internal pressure due to the high-viscosity fluid is not generated in the space defined by the axial gap in which the blade 42 is housed, and the multi-plate clutch 40 does not perform the torque transmission function.

By the way, when this differential rotation does not occur, the space 4
The working piston 36 slightly presses the multiple disc clutch 40 in the joining direction by this preload because the insides of the preload and the inside of the sections 4 and 45 are in the precompressed state, thereby performing the play of the multidisc clutch 40.

Further, when the differential rotation occurs and an internal pressure is generated in the space portions 44 and 45, the multi-plate clutch 40 slightly joined by the preload quickly comes into a pressure contact state and performs a torque transmitting action.

Incidentally, as shown in FIG. 3, the time until the multi-plate clutch is pressed and the torque is transmitted when the differential rotation A is generated has conventionally had a large time lag as shown by the line C. In the present invention, the time lag is greatly reduced as indicated by the line B.

In the above embodiment, the clutch means is a multi-plate clutch 40.
However, the present invention is not necessarily limited to the multi-plate clutch 40.

<Effects of the Invention> As described above, the present invention provides a high-viscosity fluid on the side of an operating piston that controls clutch means for transmitting torque between two shafts so as to be rotatable relative to each other by differential rotation between the two shafts. An oil pressure generating means in which an operating piston presses a clutch means by an internal pressure of a high-viscosity fluid generated in the space by the rotation of a blade housed in the space; No pre-load is applied to the enclosed space, and the operation piston is slightly pressed in the direction in which the clutch means is joined in a state where no differential rotation occurs, so that no operation rotation occurs. When the backlash of the clutch means is obtained, and the differential rotation occurs, the clutch means is quickly pressed and contacted, which has the advantage of improving the response of the rise of the transmission torque.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a sectional view of a driving force transmission device, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. FIG. 4 is a comparison diagram showing transfer characteristics. 31 ... Cap, 32 ... Cylinder housing, 33 ... Rotary shaft, 36 ... Working piston, 40 ... Other plate clutch, 41 ...
... rotor, 42 ... blade, 43, 44, 45 ... space, 50
…… Inlet, 51 …… Bolt.

Claims (1)

(57) [Claims] 1. A driving force transmission device comprising: clutch means disposed between two relatively rotatable shafts for transmitting torque between the two shafts; and a working piston for controlling transmission torque of the clutch means. A space is provided on the side of the working piston between the cylinder housing and the working piston, and a rotor is housed in this space.
Connected to one of the shafts, and connected to the cylinder housing to the other, and provided with a plurality of blades on the circumference of the rotor; these blades divide the space into a plurality of circumferences; A high-viscosity fluid is sealed in the space, and the differential piston slightly presses the space in which the high-viscosity fluid is sealed in a direction in which the clutch means is joined in a state where no differential rotation occurs between the two shafts. A driving force transmission device that is maintained in a preloaded state.