JPH04300429A - Rotary force changeover device - Google Patents

Abstract

PURPOSE:To offer a device which can change rotary force mechanically in response to resistance on the output side without depending on electronic control or the like. CONSTITUTION:One end of the 2nd drive shaft 5 that is deformable in distortion, is fixed at an output shaft 3, and the other end of the 2nd drive shaft 5 and an input shaft 2 are connected to each other through a viscous fluid layer 9. A sprag 26 engaged between the shaft 3 and a clutch outer wheel 17 is assembled to an operation retainer 22 connected with the 2nd drive shaft 5, and the 1st drive shaft 4 is made to mesh with the outer wheel 17. Also, the 1st drive shaft 4 and the input shaft 2 are connected to each other by means of gears 30, 31. When the input shaft is rotated, torque is gradually transmitted to the 2nd drive shaft through the viscous fluid layer, and the output shaft is rotated by small rotary force. When resistance added to the output shaft becomes large, the 2nd drive shaft is deformed, and the sprag is operated, and the outer wheel and output are integtated. As a result, the rotary force of the input shaft is transmitted to the linear output shaft through the 1st drive shaft.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational force switching device, and can be used, for example, to switch the driving force when starting a vehicle.

0002

BACKGROUND OF THE INVENTION When a vehicle starts or stops, the coefficient of friction generated between the tires and the road surface reaches its maximum value when the slip ratio is within a predetermined range, regardless of the road surface condition. For this reason, in order to stably start or stop a vehicle, many methods have been used to control the vehicle speed and wheel speed so that the coefficient of friction reaches its maximum value, and to control the slip rate within a predetermined range. ing.

In particular, when starting on a frozen or snowy road, if a sudden large rotational force is applied to the tires, the tires will slip violently and no drive will occur at all. A method has been proposed to finely control the friction between the tires and the road surface by applying rotational force to the tires while adding

[0004] However, in this method of controlling friction, it is necessary to provide a detector for detecting wheel speed, etc., an electronic control device, or an actuating member that operates the brake device based on the control signal. However, the structure of the drive system becomes complicated and becomes extremely expensive, and there are drawbacks such as an increase in weight.

[0005] Furthermore, since the device is expensive, its application range is limited to luxury cars and special vehicles, and there is also the problem that it is difficult to use it in inexpensive vehicles such as popular cars.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a rotational force switching device with a simple and inexpensive structure that can automatically switch the rotational force according to the magnitude of resistance on the output side without using electronic control or the like. The purpose is to

[0007]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a first drive shaft connected to an input shaft and a torsionally deformable second drive shaft connected to an output shaft in a viscous fluid layer. A clutch is connected between the output shaft and the first drive shaft by an engager rotating around the output shaft to engage and disengage the two, and the actuating member of the engager is connected to the second drive shaft. It has a connected structure.

[0008]

[Operation] In the above structure, when the input shaft is rotated with the clutch disengaged, shear resistance is generated inside the viscous fluid layer, and torque is gradually applied to the second drive shaft due to the shear action of the fluid. Therefore, the second drive shaft rotates slowly, and a small rotational force is transmitted to the output shaft.

[0009] When the frictional force applied to the output shaft increases, the second drive shaft is torsionally deformed, the engaging member is turned by the actuating member, and the clutch engages the output shaft and the first drive shaft. Therefore, the rotational force of the input shaft is directly transmitted to the output shaft via the first drive shaft. In this case, while a frictional force sufficient to deform the second drive shaft is applied to the output shaft, engagement of the clutch is maintained and the transmission path via the first drive shaft is maintained.

0010

Embodiments will be explained below based on the attached drawings.

As shown in FIG. 1, the rotational force switching device of this embodiment rotatably supports an input shaft 2 and an output shaft 3 facing each other in the axial direction inside a casing 1.
3, a first drive shaft 4 is rotatably supported.

A shaft hole 6 is formed along the axis of the output shaft 3, and a second drive shaft 5 made of a torsionally deformable material such as spring steel is inserted into the shaft hole 6. One end 5a of this second drive shaft 5 is fixed to the output shaft 3 via a pin 7,
The other end 5b of the second drive shaft 5 protruding from the output shaft 3 is inserted into the bottomed hole 8 provided in the input shaft 2. Further, inside the bottomed hole 8, a viscous fluid layer 9 is provided that connects the input shaft 2 and the second drive 5.

The connection structure inside the bottomed hole 8 forms a so-called viscous coupling, and connects the peripheral surface of the inner shaft 10 integrally fixed to the end of the second drive shaft 5 with the input shaft 2. A large number of plates 12 are alternately protruded from the inner peripheral surface of the bottomed hole 8 through spacers 11, and a viscous fluid layer 9 such as silicone oil is filled between the plates 12. In this structure, when the input shaft 2 rotates, a viscous fluid layer 9 sticks to the input shaft and the second drive shaft.
Shearing resistance is generated inside the second drive shaft 5, and torque is generated on the circumferential surface of the second drive shaft 5.

A radial operating pin 14 inserted through the pin hole 13 of the output shaft 3 is fixed to the center of the second drive shaft 5, and the output shaft 3 and A clutch 15 that engages and disengages the first drive shaft 4 is connected.

This clutch 15, as shown in FIG.
An outer ring 17 is rotatably supported on the circumferential surface of the output shaft 3 by bearings 16, 16, and gear teeth 19 that mesh with gear teeth 18 on the circumferential surface of the first drive shaft 4 are integrally formed on the outer ring 17. Between the cylindrical engagement surfaces 20 and 21 formed on the opposing surfaces of the outer ring 17 and the output shaft 3, a rotating large-diameter operating retainer 22 and a small-diameter fixed retainer 23 fixed to the output shaft 3 are provided. It incorporates.

In addition, a sprag 26 as an engager and an elastic member 27 for controlling the attitude of the sprag are respectively incorporated into a plurality of pockets 24 and 25 provided opposite to the operating retainer 22 and the fixed retainer 23. , the actuation pin 14 is integrally fixed to the actuation holder 22.

The sprag 26, as shown in FIG.
The inner diameter side and the outer diameter side are formed by an arcuate surface 28 having a curve center on the center line of the sprag, and when tilted at a predetermined angle in both left and right directions, it engages with both engaging surfaces 20 and 21 to connect the outer ring 17 and output shaft 3. Unify. Further, the elastic member 27 is supported by the actuating holder 22 and normally presses both sides of the sprag 27 to hold it in a neutral position where the arcuate surface 28 does not engage with the engagement surfaces 20 and 21.

As shown in FIG. 3, the actuating pin 14 is integrally connected to the second drive shaft 5 and the actuating retainer 22 without a gap, but there is a gap in the rotational direction between the actuating pin 14 and the pin hole 13. 29 will be provided. The size of the rotational direction clearance 29 is:
The distance is set to be greater than the distance from the neutral position until the sprag 26 engages with the engagement surfaces 20 and 21 via the elastic member 27.

On the other hand, gear teeth 30 are formed on the circumferential surface of the second drive shaft 5 facing the input shaft 2, and gear teeth 31 that mesh with the gear teeth 30 are formed on the outer circumferential surface of the input shaft 2. 2
and the first drive shaft 4 rotate together.

The rotation switching device of this embodiment has the above-mentioned structure, and in order to use it for switching the rotational force when starting the vehicle, the casing 1 is fixed to the vehicle body, and the casing 1 is fixed to the vehicle propeller shaft. The input shaft 2 and output shaft 3 are connected to each other. In this case, the gear ratio between the propeller shaft and the input shaft is appropriately set so that the rotation speed of the input shaft 2 is always higher than the rotation speed of the propeller shaft, as will be explained later.

When the input shaft 2 is not rotating, the sprag 26 is held in a neutral position by the elastic member 27, and the clutch 15 is in a disengaged state. There is no resistance on the output shaft 3,
When the input shaft 2 rotates, the first drive shaft 4 does not engage the clutch with the output shaft 3.

Therefore, the rotational force of the input shaft 2 is gradually transmitted to the second drive shaft 5 due to the shearing action of the viscous fluid layer 9.
The output shaft 3 is rotated via the second drive shaft 5.

In this case, if the difference in rotational speed input from the input shaft 2 is small, the shear resistance generated inside the viscous fluid layer 9 is also small, and the transmitted torque is also small, so the output shaft 3 rotates extremely slowly. be done. Therefore, it is possible to start the vehicle smoothly even on a road surface with a small coefficient of friction, such as a snowy road or a frozen road surface.

When the rotational force is transmitted through the second drive shaft 5 in this manner, the second drive shaft 5 is twisted between the pin 7 and the viscous fluid layer 9. If the value of the spring force that causes the second drive shaft torsionally deform is set so as to balance the coefficient of friction between the tires and the road surface on snowy roads, frozen roads, etc., when the vehicle starts slowly, the operating pin 14 The operating retainer 22 is rotated, the sprag 26 engages with both the engagement surfaces 20 and 21, and the clutch 15 integrates the output shaft 3 and the first drive shaft 4. Therefore, when the vehicle starts and sufficient frictional force is generated in the tires, the rotation of the input shaft 2 is transmitted to the output shaft 3 via the first drive shaft 4, and the output shaft 3 is driven with a large rotational force. Can be done.

Furthermore, in this case, as mentioned above, the input shaft 2
Since the clutch 15 is set to rotate faster than the propeller shaft rotation speed, the clutch 15 is always engaged while the output shaft 3 is subjected to large resistance from the road surface, such as when driving on a road surface with a high coefficient of friction. The state is maintained, and the output shaft 3 is driven while being directly connected to the input shaft 2.

In the structure shown in FIG. 1, the same effect can be obtained even if the input shaft 2 is directly connected to the first drive shaft 4 and the viscous fluid layer 9 is rotated via the first drive shaft 4. Can be done. In this case, the input shaft 2 and output shaft 3 rotate in opposite directions.

[0027] As for the sprags as the clutch engagers, sprags that engage by tilting in one direction may be combined in the left and right direction, or rollers may be used.

Further, although a viscous coupling is shown as a connection structure using a viscous fluid layer, the present invention is not limited to this, and other coupling structures using a viscous fluid can also be used.

[0029]

[Effects] As described above, the rotational force switching device of the present invention deforms the second drive shaft connected to the output shaft, thereby changing the drive path between the input and output to a direct connection via a viscous fluid layer. Therefore, the magnitude of the rotational force that can be mechanically transmitted can be changed by the resistance applied to the output side.

Furthermore, changes in resistance on the output side are automatically detected by the operation of the built-in second drive shaft and clutch.
The rotational force can be switched with an extremely simple structure without using a speed detector or electronic control device.

Therefore, if the present invention is applied to the drive system of a vehicle, it is possible to stably start the vehicle on a road surface with low frictional resistance, and the structure of the drive system can be simplified and costs reduced. be.

[Brief explanation of the drawing]

[Figure 1] Longitudinal front view of the example

[Fig. 2] Cross-sectional view taken along line II-II in Fig. 1

[Figure 3] Cross-sectional view taken along line III-III in Figure 1

[Figure 4] Figure 3
Enlarged sectional view of main parts of

[Explanation of symbols]

2 Input shaft 3 Output shaft 4 First drive shaft 5 Second drive shaft 9 Viscous fluid layer 14 Actuation pin 15 Clutch 22 Operating retainer 26 Sprag 27 Elastic member

Claims (1)

[Claims] 1. A first drive shaft connected to the input shaft and a torsionally deformable second drive shaft connected to the output shaft are connected via a viscous fluid layer, and between the output shaft and the first drive shaft, A rotational force switching device that incorporates a clutch that engages and disengages both by an engager that rotates around an output shaft, and that connects the operating member of the engager to a second drive shaft.