JP3843824B2 - Friction device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a friction device that is preferably used for, for example, a transmission of an automobile or a transfer of a four-wheel drive vehicle, and mainly reduces rattling noise between gears.
[0002]
[Prior art]
For example, in a transmission of an automobile or a transfer of a four-wheel drive vehicle, there is a possibility that an unpleasant noise such as a so-called rattling noise may be generated at a meshing portion of the drive gear and the driven gear. As an example of countermeasures against such abnormal noise, a friction damper that prevents frictional rotation of the rotating body by preventing friction of the rotating body by applying friction in the rotating direction to the rotating body that is rotationally driven via a gear. (Friction device) is known (Japanese Patent Laid-Open No. 11-344040, etc.).
[0003]
[Problems to be solved by the invention]
However, the conventional friction damper is configured to always add friction during rotation of the rotating body. Therefore, even in a situation where no noise is generated even if no friction is applied, for example, when the rotating body is rotating at a constant speed, friction is added wastefully, and a decrease in efficiency such as fuel consumption cannot be avoided. . In addition, since friction always acts on the friction member made of rubber or the like while the rotating body is rotating, wear and deterioration of the friction member are likely to proceed, and it is difficult to maintain the desired performance for a long period of time. .
[0004]
The present invention has been made paying attention to such a problem, and an object of the present invention is to provide a novel friction device that does not unnecessarily give friction and has high durability and efficiency.
[0005]
[Means for Solving the Problems]
The friction device according to the present invention includes a rotating body and a friction member that applies friction in the rotational direction to the rotating body. The rotating body is typically rotationally driven via a drive gear and a driven gear that may generate rattling noise. The present invention provides an inertial body that is disposed coaxially with the rotary body and is elastically supported so as to be relatively rotatable with the rotary body, and an inertial body and a rotary body that are generated when the vehicle is accelerated and decelerated. depending on the relative rotation, have a, an actuation mechanism for actuating the friction member, the actuation mechanism, an oil pump for generating hydraulic pressure by the relative rotation between the rotor and the inertial body, from the oil pump The hydraulic circuit includes an actuator that drives the friction member with the supplied hydraulic pressure to apply friction in the rotational direction to the rotating body .
[0006]
According to the present invention, the friction member is operated by the operating mechanism only when the speed of the rotating body is likely to generate noise such as rattling noise between the gears. In other words, the rotating body rotates at a constant speed. The friction member does not operate when there is no possibility of generating an abnormal noise as in the case of unnecessary, and unnecessary friction is not given to the rotating body. For this reason, efficiency, such as a fuel consumption, improves, and durability of a friction member improves. In addition, the operation mechanism can be mechanically realized by using an inertial body, for example, without requiring a sensor for detecting the speed fluctuation of the rotating body, a control means for driving / controlling the actuator in accordance with this sensor, etc. Therefore, simplification and cost reduction can be achieved.
[0009]
【The invention's effect】
As described above, according to the present invention, friction can be applied to the rotating body only when necessary, so there is no waste and durability is improved, and when applied to a vehicle, fuel efficiency and the like are improved. I can plan.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which a friction damper as a friction device according to the present invention is applied to a front-wheel drive-based standby four-wheel drive vehicle will be described in detail with reference to the drawings.
[0011]
Referring to FIG. 1, an engine 1 and a transaxle 2 are disposed in front of the vehicle. The rotational power output from the transaxle 2 is transmitted to the front drive shaft 3 and is also transmitted to the propeller shaft 5 via the transfer 4. A rear final drive 7 is interposed between the propeller shaft 5 and the rear drive shaft 6. The rear final drive 7 is provided with a torque control coupling 8 for intermittently transmitting power from the propeller shaft 5 to the rear drive shaft 6. A friction damper 10 according to this embodiment is provided on a rotating shaft 5 a that rotates integrally with the propeller shaft 5. The friction damper 10 gives a predetermined friction (rotation resistance, friction resistance) to a rotating shaft 5a that rotates integrally with the propeller shaft 5 on the driven side, so that, for example, the propeller shaft 5 idles during vehicle deceleration. As a result, it has a function of preventing abnormal noise such as rattling noise and vibration caused by backlash between the drive gear 4a and the driven gear 4b in the transfer 4 meshing with each other.
[0012]
Referring to FIGS. 2, 3 and 4, the friction damper 10 is fixed to or integrally formed with the rotating shaft 5a, and has a substantially cylindrical rotating body 11 that rotates integrally with the rotating shaft 5a, and the rotating body. 11 is arranged coaxially on the outer peripheral side of 11, is driven to rotate by the rotating body 11, and is substantially annular inertia ring (inertia) elastically supported so as to be relatively rotatable with respect to the rotating body 11 within a predetermined range. Body) 12, a pair of friction plates 13 as a friction member for applying predetermined friction to the rotating body 11, and an operating mechanism 14 for operating the friction plate 13 when the rotating body 11 and the inertia ring 12 rotate relative to each other. And have.
[0013]
A pair of recesses 15 recessed inward in the radial direction are formed diagonally on the outer peripheral portion of the rotating body 11, and a pair of vanes 16 protruding radially inward are paired on the inner peripheral portion of the inertia ring 12. It is formed at the corner. Each vane 16 is accommodated and disposed in the recess 15 so as to be movable within a predetermined range in the circumferential direction. A total of four springs 17 that elastically support the vane 16 at an intermediate position of the recess 15 are interposed between the both sides in the circumferential direction of the vane 16 and the both sides in the circumferential direction of the recess 15. The spring 17 is set so that the resonance frequency in the rotational direction is lower than the frequency of the rotational speed fluctuation during normal use. Therefore, the inertia ring 12 can rotate at a constant speed without being affected by fluctuations in rotational speed during normal use. For example, the friction plate 13 can be the same as a brake shoe of a drum brake. That is, the friction plates 13 are provided in a pair on the diagonal of the outer peripheral portion of the rotating body 11, have a substantially semicircular arc shape along the outer peripheral portion of the rotating body 11, and are supported on the rotating body 11 by the pivot anchor portion 13 a at one end. Thus, a predetermined friction is applied to the rotating body 11 by being pressed against the casing 18 as a non-rotating body.
[0014]
The operating mechanism 14 includes four oil pumps 20 for supplying hydraulic oil (engine oil) as a working fluid when the inertia ring 12 and the rotating body 11 rotate relative to the spring force of the spring 17. The hydraulic circuit includes two actuators 30 that drive the friction plate 13 in accordance with hydraulic oil (hydraulic pressure and flow rate) supplied from the oil pump 20.
[0015]
The oil pump 20 has a total of four cylinders 21 attached to the rotating body 11 in a posture facing the recess 15, and pistons 22 that are slidably fitted in the cylinders 21. The piston 22 is linked to the circumferential side surface of the vane 16 of the inertia ring 12 by a rod 23 having a link 24. Referring to FIG. 5, the inside of cylinder 21 is liquid-tightly defined by an oil supply chamber 25 and an oil return chamber 26 by a piston 22. The piston 22 is provided with a check valve 27 that prevents the flow from the oil supply chamber 25 to the oil return chamber 26 and allows the flow from the oil return chamber 26 to the oil supply chamber 25.
[0016]
The actuator 30 includes a pair of cylinders 31 attached to the rotating body 11 in a posture toward the friction plate 13 and pistons 32 that are slidably disposed in the cylinders 31. The piston 32 and the friction plate 13 are linked by a rod 33 having a link 34. Referring to FIG. 6, the inside of the cylinder 31 is defined by a hydraulic chamber 35 filled with hydraulic oil and an atmospheric chamber 36 opened to the atmosphere by a piston 32, and a return spring 37 is provided in the atmospheric chamber 36. It has been.
[0017]
The oil outlet 28 of the oil supply chamber 25 and the oil inlet 38 of the hydraulic chamber 35 are connected via a first oil passage 41 (see FIGS. 2 and 3), and the oil outlet 39 of the hydraulic chamber 35 and the oil return chamber are connected. 26 oil inlets 29 are connected via a second oil passage 42 (see FIGS. 2 and 3). The oil outlet 39 is set to have a smaller channel cross-sectional area than the oil inlet 38 and functions as a so-called orifice. Therefore, when hydraulic oil is supplied from the oil inlet 38 into the hydraulic chamber 35, the pressure in the hydraulic chamber 35 rises, and the piston 32 resists the urging force of the return spring 37 (the upper side in FIG. 6). Move to).
[0018]
In this embodiment, in order to absorb the increase or decrease of the volume in the hydraulic chamber 35 accompanying the movement of the piston 32, that is, the oil amount, a substantially cylindrical reservoir tank 43 that stores hydraulic oil is provided in the middle of the second oil passage 42. The rotating body 11 is attached coaxially. Referring to FIG. 7, this reservoir tank 43 is provided with an air release port 44 that is open to the atmosphere at a substantially central portion of one axial side wall, and at a substantially central portion of the other axial side wall, An oil inlet 45 connected to the oil outlet 39 is provided. An oil supply port 46 connected to the oil inlet 29 of the oil pump 20 is provided on the outer periphery of the reservoir tank 43. A baffle 47 is provided around the atmosphere opening port 44 to prevent the hydraulic oil from entering the atmosphere opening port 44 side. By this baffle 47, the reservoir tank 43 has a reservoir chamber 48 for storing the working oil and the atmosphere. It is separated from a breather chamber 49 connected to the opening 44. The shape of the reservoir tank 43, the maximum amount of oil in the reservoir chamber 48, and the like are set so that the hydraulic oil does not enter the breather chamber 49 from the reservoir chamber 48 even when stopped.
[0019]
When the speed fluctuation of the rotating body 11 deviates from the normal range and becomes large as during vehicle deceleration, the rotating body 11 and the inertia ring 12 relatively rotate (vibrate) against the spring force of the spring 17. At this time, in the oil pump 20, the piston 22 connected to the inertia ring 12 through the link 24 moves in the cylinder 21. Referring to FIG. 5, when piston 22 moves in the direction of arrow (1), check valve 27 opens and hydraulic oil flows from oil return chamber 26 to oil supply chamber 25. Almost no hydraulic oil is supplied. On the other hand, when the piston 22 moves in the direction of the arrow (2), the check valve 27 is closed and the hydraulic oil does not flow from the oil supply chamber 25 to the oil return chamber 26. Accordingly, the hydraulic oil in the oil supply chamber 25 is supplied from the oil outlet 28 to the actuator 30 via the first oil passage 41, and the hydraulic oil is supplied from the reservoir tank 43 to the oil return chamber 26 via the oil inlet 29. Supplied. Since the oil pump 20 is disposed on both sides of the vane 16 as shown in FIG. 3, when one moves in the direction of the arrow (1), the other moves in the direction of the arrow (2). Therefore, if the inertia ring 12 and the rotating body 11 rotate relative to each other, the hydraulic oil is supplied to the actuator 30 regardless of the rotation direction.
[0020]
When hydraulic oil is supplied to the hydraulic chamber 35 of the actuator 30, the oil pressure in the hydraulic chamber 35 rises due to the orifice action of the oil outlet 39 described above, and the piston 32 is pushed out against the spring force of the return spring 37. It is. As a result, the friction plate 13 is pressed against the casing 18, and friction is applied to the rotating body 11. Since this friction is proportional to the pressing force of the friction plate 13, the friction proportional to the flow rate flowing into the cylinder 31 acts.
[0021]
According to the present embodiment as described above, the rotating body 11 and the inertia ring are in an operating state in which abnormal noise such as rattling noise may occur between the gears 4a and 4b, such as during vehicle acceleration and deceleration. 12 and the friction plate 13 are pressed against the casing 18 by the operating mechanism 14 in accordance with the relative rotation operation, and the friction acts on the rotating body 11 to prevent the generation of the abnormal noise. . On the other hand, in an operation state at a substantially constant speed that does not cause a rattling sound or the like, the rotating body 11 and the inertia ring 12 rotate in synchronization. Waste due to the addition of friction is eliminated, the durability of the friction plate 13 is improved, and fuel efficiency and the like are improved.
[0022]
Moreover, since all the components of the friction damper 10 including the inertia ring 12 and the hydraulic circuit can be coaxially attached to the rotary shaft 5a except for the casing 18 against which the friction plate 13 is pressed, the layout is highly flexible and compact. Can be easily applied.
[0023]
Furthermore, the inertia ring 12 can be used to mechanically configure the operating mechanism 14 that operates in accordance with the speed fluctuation of the rotating body 11. For example, a sensor that detects the speed fluctuation of the rotating body 11, Accordingly, no control means for driving / controlling the actuator is required, so that simplification and cost reduction can be achieved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a vehicle to which a friction damper according to an embodiment of the present invention is applied.
FIG. 2 is a configuration diagram showing a friction damper of the present embodiment.
3 is a cross-sectional view along the line AA ′ in FIG. 2;
4 is a cross-sectional view along the line BB ′ in FIG. 2;
FIG. 5 is a cross-sectional view showing an oil pump of the friction damper.
FIG. 6 is a cross-sectional view showing the actuator of the friction damper.
FIG. 7 is a cross-sectional view showing a reservoir tank of the friction damper.
[Explanation of symbols]
10 ... Friction damper (friction device)
11 ... Rotating body 12 ... Inertia ring (inertial body)
13. Friction plate (friction member)
14 ... Actuating mechanism 20 ... Oil pump 30 ... Actuator 43 ... Reservoir tank

Claims (1)

In a friction device having a rotating body that is rotationally driven through a gear, and a friction member that imparts friction in the rotational direction to the rotating body,
An inertial body disposed coaxially with the rotating body, and rotatably and elastically supported by the rotating body;
An actuation mechanism for actuating the friction member in response to relative rotation between the inertial body and the rotating body that occurs during acceleration and deceleration of the vehicle ;
Have a,
This operating mechanism applies an oil pump that generates hydraulic pressure by the relative rotational operation of the inertial body and the rotating body, and drives a friction member by the hydraulic pressure supplied from the oil pump to impart friction in the rotational direction to the rotating body. And a hydraulic circuit including an actuator for performing friction.

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