JP2003090354A - Limiter device of excessive torque - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce torque pulsation by stably cutting the excessive torque and to make a connected mechanical mechanism which is compact and lightweight. SOLUTION: Between a torque input member 30 fixed to a crank shaft 10 of an engine and rotates with a crankshaft 10, and a torque transmitting member 50 connected to a torque output member 40 that is fixed to an input shaft 12 of mechanical mechanism such as a transmission and rotates with the input shaft 12 through a coil spring 48, a wet friction member 58 is arranged to which predetermined compression stress by the energizing force from a belleville spring 56 is applied. When an excessive torque is supplied to a torque input member 130 by the energizing force, the excessive torque input to the input shaft 12 to which the torque output member 40 is fixed can be prevented by sliding the wet friction member 58. As a result, the strength required for the mechanical mechanism connected to the input shaft 12 is decreased and the size and weight can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excessive torque limiting device, and more particularly, to an excessive torque limiting device that limits torque from an internal combustion engine and transmits the torque to an input shaft of a mechanical mechanism.

[0002]

2. Description of the Related Art Conventionally, an excessive torque limiting device of this type has been connected to a crankshaft serving as an output shaft of an internal combustion engine and also connected to a fluid type torque converter.
There has been proposed a damper that reduces pulsating torque and outputs the pulsating torque output from an internal combustion engine to a crankshaft to a torque converter. This damper is provided with a spring member having a predetermined spring coefficient in the input side member connected to the crankshaft and the output side member connected to the torque converter, and by reducing the pulsation of torque by the elastic motion of the spring member. It prevents excessive torque from being input to the torque converter.

[0003]

However, if such a damper is directly connected to a mechanical mechanism such as a transmission without a torque converter, an excessive torque is not sufficiently suppressed. There has been a problem that the required strength is increased and the physique and weight of the mechanical mechanism are increased.

One object of the excessive torque limiting device of the present invention is to stably cut excessive torque to reduce torque pulsation. Another object of the excessive torque limiting device of the present invention is to reduce the size and weight of the connected mechanical mechanism.

As a method for solving at least a part of the above-mentioned problems, the applicant has proposed an excessive torque limiting device provided with a dry torque limiter for preventing excessive torque transmission from the internal combustion engine. (Prius new model car manual).

[0006]

Means for Solving the Problem and Its Action / Effect The excessive torque limiting device of the present invention employs the following means in order to achieve at least a part of the above objects.

A first excessive torque limiting device of the present invention is an excessive torque limiting device for limiting torque from an internal combustion engine and transmitting the torque to an input shaft of a mechanical mechanism, the output shaft of the internal combustion engine. A torque input member connected to the torque input member, a torque transmission member capable of transmitting torque to the input shaft of the mechanical mechanism, a wet friction member arranged in contact with the torque input member and the torque transmission member, and And a compressive stress acting means for exerting a predetermined compressive stress on the wet friction member by applying a predetermined force to the torque input member and the torque transmission member.

In the first excessive torque limiting device of the present invention, the wet friction member, which has a predetermined compressive stress by the compressive stress acting means, exerts an excessive torque that overcomes the frictional resistance acting on the basis of the compressive stress. It is possible to prevent an excessive torque from being transmitted to the mechanical mechanism because it slips when input from the output shaft of the. The frictional resistance of the wet friction member immediately before slipping varies depending on the state of the friction surface of the wet friction member, but the wet friction member can maintain the friction surface in a uniform state to some extent. It is possible to reduce the variation in frictional resistance immediately before sliding. That is, it is possible to reduce the variation in the maximum value of the torque transmitted to the mechanical mechanism. As a result, the strength required for the mechanical mechanism can be reduced, and the physique and weight can be reduced.

In the first excessive torque limiting device of the present invention, the space in which the wet friction member is arranged may be liquid-sealed with a predetermined liquid.
By doing so, it is possible to keep the friction surface of the wet friction member always wet with the predetermined liquid and keep this friction surface in a uniform state, so that the variation in the frictional resistance force immediately before the wet friction member slips is further reduced. can do. As a result, it is possible to further reduce the variation in the maximum value of the torque transmitted to the mechanical mechanism.

Also, in the first excessive torque limiting device of the present invention, a torque output member connected to the input shaft of the mechanical mechanism, and a predetermined elasticity connected to the torque output member and the torque transmission member are provided. Elastic means for reducing the pulsation of torque may be provided. With this, it is possible to reduce the pulsation of the torque transmitted from the torque transmission member to the torque output member. As a result, the strength required for the mechanical mechanism can be further reduced,
The physique and weight can be further reduced. A spring having a predetermined spring constant can be used as the elastic means.

The first aspect of the present invention in the mode including the elastic means.
The torque pulsation means may be provided with damping means arranged in parallel with the elastic means for damping the torque pulsation. With this, the pulsation of the torque transmitted from the torque transmission member to the torque output member can be further reduced, so that the strength required for the mechanical mechanism can be further reduced, and the physique and weight can be further reduced. be able to. In the first excessive torque limiting device of the present invention in this aspect, the damping means may be a means including at least one orifice. Further, in the first excessive torque limiting device of the present invention in this aspect, the damping means is formed by liquid-sealing a space in which the wet friction member is arranged and the liquid so that the liquid can pass therethrough. It may be a means including the orifice.

A second excessive torque limiting device of the present invention is an excessive torque limiting device for limiting torque of an internal combustion engine and transmitting the torque to an input shaft of a mechanical mechanism, the output shaft of the internal combustion engine. A torque input member connected to the torque input member, a torque output member connected to the input shaft of the mechanical mechanism, and an elastic means connected to the torque input member and the torque output member to reduce torque pulsation by a predetermined elasticity. And a damping unit arranged in parallel with the elastic unit to damp torque pulsation.

In the second excessive torque limiting device of the present invention, in addition to the reduction of the pulsation of the torque from the internal combustion engine by the elastic means, the damping of the torque from the internal combustion engine by the damping means arranged in parallel with the elastic means. Since the pulsation is dampened, it is possible to suppress excessive torque from being transmitted to the input shaft of the mechanical mechanism. As a result, the strength required for the mechanical mechanism can be reduced, and the physique and weight can be reduced. A spring having a predetermined spring constant can be used as the elastic means.

In the second excessive torque limiting device of the present invention, the damping means may be a means including at least one orifice. In the second excessive torque limiting device of the invention of this aspect,
The attenuating means may be a means including a liquid that seals a space between the torque input member and the torque output member, and the orifice that is arranged so that the liquid can pass therethrough. it can.

In the first or second excessive torque limiting device of the present invention in any of the above-mentioned aspects, the mechanical mechanism is a gear mechanism having a rotating shaft to which an electric motor or a generator is connected. You can also By doing this, it is possible to prevent excessive torque from being transmitted to the input shaft of the mechanical mechanism, and as a result, prevent excessive torque from being input to the motor or generator connected to the rotary shaft of the mechanical mechanism. Therefore, the electric motor and the generator can be protected.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a schematic diagram showing a configuration of a hybrid vehicle 5 including an excessive torque limiting device 20 according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a configuration of an excessive torque limiting device 20 according to an embodiment. It is a block diagram. As shown in FIG. 1, a hybrid vehicle 5 including the excessive torque limiting device 20 of the embodiment includes an engine 9 and an excessive torque limiting device 20 of the embodiment connected to a crankshaft 10 that is an output shaft of the engine 9, A planetary gear 13 as a mechanical mechanism in which a carrier as an input shaft 12 is connected to the excessive torque limiting device 20, a motor 16 capable of inputting / outputting power to / from a sun gear shaft connected to a sun gear of the planetary gear 13, and a planetary gear 13 Connected to the ring gear and the differential gear 18
A drive shaft 15 that outputs power to drive wheels 19a and 19b via a motor 17 capable of inputting and outputting power.

The excessive torque limiting device 20 of the embodiment is shown in FIG.
As shown in, the torque input member 30 fixed to the crankshaft 10 of the engine 9 by bolts and the like and rotating with the crankshaft 10 and the input shaft 12 of the planetary gear 13 as a mechanical mechanism fixed by spline coupling or bolts and input. A torque output member 40 that rotates with the shaft 12, a torque transmission member 50 that is connected to the torque output member 40 by a coil spring 48 and that can transmit torque to the input shaft 12 via the torque output member 40 and the coil spring 48, and a torque input. The wet friction member 58 is provided between the member 30 and the torque transmission member 50, and the damping orifice member 60 is attached to the torque output member 40.

The torque input member 30 is formed in a bowl shape whose bottom is the rotation axis of the crankshaft 10, and the torque output member 40 and the torque transmission member 50 are provided inside thereof.
Is stored. The inside of the torque input member 30 is sealed by a lid member 32 attached to an open end (left side in the drawing) and seal members 34 and 36, and the sealed space is filled with a liquid such as oil. There is.

The wet friction member 58 is formed so that the porosity is about 50% by using a binder such as a phenol resin and the like as a main base material such as a cellulose fiber or a heat resistant organic fiber, and an organic material such as cash dust or rubber dust. Friction modifiers such as solid lubricants such as dust, graphite and metal oxides, oil retaining agents such as diatomaceous earth are used. As described above, since the inside of the torque input member 30 is liquid-sealed with the liquid, the wet friction member 58 is wet with the liquid-sealed liquid.

A disc spring 56 is mounted between the torque transmitting member 50 and the lid member 32.
A predetermined compressive stress is applied to the wet friction member 58 arranged between the torque transmission member 50 and the torque output member 40 by the urging force of 6. The wet friction member 58 receives the torque input member 30 and the torque transmission member 50 according to the compressive stress.
It exerts a predetermined frictional force against and. Here, disc spring 5
The urging force of 6 is set based on the maximum static friction force to be generated by the wet friction member 58,
It is determined by the characteristics of the engine that outputs torque to the crankshaft 10 and the characteristics of the mechanical mechanism that is connected to the input shaft 12.

Torque output member 40 and torque transmission member 50
The coil spring 48 that connects the torque output member 40 and the torque transmission member 5 has a predetermined spring constant.
A force for returning the position relative to the displacement of the position in the rotational direction relative to 0 is generated, and this force reduces the pulsation of the torque transmitted from the torque transmission member 50 to the torque output member 40.

The damping orifice member 60 attached to the torque output member 40 is formed as a plate-shaped member, and a plurality of orifices 62 penetrating therethrough are formed.
As described above, since the inside of the torque input member 30 is liquid-sealed, when the torque output member 40 is displaced in the rotational direction with respect to the torque transmission member 50, a part of the filled liquid is displaced. Accordingly, the damping orifice member 6
0 through a plurality of orifices 62. At this time, a force is exerted on the damping orifice member 60 in a direction to moderate the rotational displacement speed of the torque output member 40 with respect to the torque transmission member 50, and this force is transmitted from the torque transmission member 50 to the torque output member 40. Reduce the torque pulsation caused. The reduction of the torque pulsation by the damping orifice member 60 can be considered as a parallel relationship with the reduction of the torque pulsation by the coil spring 48 described above.

Next, the operation of the excessive torque limiting device 20 thus constructed, particularly the operation of torque transmission, will be described. The torque output from the engine (not shown) to the crankshaft 10 and input to the torque input member 30 is input to the torque transmission member 50 via the static friction force or the kinetic friction force of the wet friction member 58. That is, when the torque T1 of the torque input member 30 does not exceed the maximum friction torque Tmax corresponding to the maximum static friction force of the wet friction member 58, the wet friction member 58 does not slip, so the torque T1 is directly input to the torque transmission member 50. To be done. On the other hand, the torque T1 of the torque input member 30 is the maximum stationary torque Tmax.
When it exceeds, the wet friction member 58 slides with the kinetic frictional force, so that the torque corresponding to the kinetic frictional force is input to the torque transmission member 50. The wet friction member 58 maintains a wet state with the liquid that seals the inside of the torque input member 30, so that the friction surface of the wet friction member 58 is always maintained in a uniform state. Therefore, the maximum static frictional force and the kinetic frictional force applied by the wet friction member 58 are substantially constant, and the variation in the torque (maximum static torque Tmax) when the wet friction member 58 slides is small. That is, the wet friction member 58 acts as a stable torque limiter. In addition, since slippage on a wet friction surface is often unclear theoretically, the kinematic friction coefficient at extremely low speed sliding is often used as the maximum static friction coefficient. That is, the maximum static friction coefficient can be equated with the kinetic friction coefficient in extremely low speed sliding. Therefore, in the embodiment, the maximum stationary torque Tmax and the torque for extremely low speed slip will be the same. The torque T2 thus input to the torque transmission member 50 is transmitted to the torque output member 40 as the torque T3 having a small torque pulsation through the reduction of the pulsation by the coil spring 48 and the reduction of the pulsation by the damping orifice member 60, and the input shaft 12 Is output to. If this relationship is schematically shown, the excessive torque limiting device 20 of the embodiment can be represented as shown in FIG. As is apparent from FIG. 3, in the excessive torque limiting device 20 of the embodiment, the wet friction member 58 acts as a torque limiter for the torque input from the crankshaft 10,
The coil spring 48 and the damping orifice member 60 act as a torque pulsation reducing section arranged in parallel with respect to the torque limited torque.

FIG. 4 shows the torque T1 of the torque input member 30.
And the torque T2 of the torque transmission member 50 and the torque output member 4
It is explanatory drawing which shows an example of the time series change of the torque T3 of 0. Now, the pulsating torque T1 that exceeds the maximum static torque Tmax corresponding to the maximum static friction force of the wet friction member 58.
Will be input to the torque input member 30 from the crankshaft 10. The torque T2 input to the torque transmission member 50 is limited to the maximum static torque Tmax by the wet friction member 58, and the torque T3 input to the torque output member 40 is arranged in parallel.
And the damping orifice member 60 reduces the pulsation.

According to the excessive torque limiting device 20 of the embodiment described above, by using the wet friction member 58,
The torque T1 input to the torque input member 30 can be stably limited by the maximum static torque Tmax. As a result, the strength required for the planetary gear 13 connected to the input shaft 12 can be reduced, and the physical size and weight of the planetary gear 13 can be reduced. Further, since it is possible to limit the input of the excessive torque to the planetary gear 13 in this way, the excessive torque is inputted to the motor 16 connected to the sun gear shaft 14 of the planetary gear 13 and the motor 17 connected to the drive shaft 15. Can be prevented, and the motor 16 and the motor 17 can be protected.

Further, according to the excessive torque limiting device 20 of the embodiment, the pulsation is reduced by the coil spring 48 and the damping orifice member 60 which are arranged in parallel with the torque limited by the wet friction member 58. can do. As a result, the strength required for the planetary gear 13 connected to the input shaft 12 can be further reduced, and the physical size and weight of the planetary gear 13 can be further reduced. Of course, the motor 16 and the motor 17 can be protected.

In the excessive torque limiting device 20 of the embodiment, the coil spring 48 and the damping orifice member 60 are provided to reduce the torque limited by the wet friction member 58.
8 or the damping orifice member 60, only one of them may be provided, or neither the coil spring 48 nor the damping orifice member 60 may be provided.

In the excessive torque limiting device 20 of the embodiment, the wet friction member 58 is formed so that the porosity is about 50% by using a binder such as a cellulose resin or a heat resistant organic fiber as a main base material and a phenol resin. In addition to the above-mentioned materials, organic dust such as cash dust and rubber dust, solid lubricant such as graphite and metal oxide, and friction modifier such as oil retaining agent such as diatomaceous earth were used. The friction modifier may be used in addition to the one formed in the above.

In the excessive torque limiting device 20 of the embodiment, the planetary gear 1 as a mechanical mechanism is connected via the input shaft 12.
However, it may be connected to any mechanical mechanism having a gear mechanism such as a transmission.

Next, an excessive torque limiting device 120 of the second embodiment of the present invention will be described. FIG. 5 is a configuration diagram showing an outline of the configuration of the excessive torque limiting device 120 of the second embodiment. As shown in the figure, the excessive torque limiting device 120 according to the second embodiment has a state in which the torque transmission member 50 is fixed to the crankshaft 10 by removing the portion related to the wet friction member 58 from the excessive torque limiting device 20 according to the first embodiment. Like the overtorque limiting device 20 of the first embodiment, the crankshaft 10 of the engine 9 and the input shaft 12 of the planetary gear 13 as a mechanical mechanism have the same structure. Connected to the carrier. The excessive torque limiting device 2 of the first embodiment
In order to distinguish it from 0, in the following description, the reference numerals given to the respective members will be explained by adding 100. As shown in FIG. 5, the excessive torque limiting device 120 of the second embodiment includes a torque input member 130 fixed to the crankshaft 110 and rotating with the crankshaft 110, and an input shaft 112 fixed to the input shaft 112 of the planetary gear 113.
12 and a coil spring 148 attached to the torque input member 130 and the torque output member 140 to reduce pulsation of torque transmitted from the torque input member 130 to the torque output member 140.
And a damping orifice member 160 having a plurality of orifices 162 attached to the torque output member 140.
And a torque input member 130 and a lid member 13
A liquid such as oil is filled in the closed space formed by 2 and the seal members 134 and 136.

Therefore, in the excessive torque limiting device 120 of the second embodiment, the coil spring 148 and the damping orifice member 160 are connected in parallel to reduce the pulsation of the torque transmitted from the torque input member 130 to the torque output member 140. Functions as a torque pulsation reduction unit. Second in FIG.
The excessive torque limiting device 120 of an Example is shown typically.

FIG. 7 shows the torque T of the torque input member 130.
4 is an explanatory diagram showing an example of a time series change of torque T5 of torque output member 140 and torque output member 140. FIG. Now, consider a case where the pulsating torque T4 is input from the crankshaft 110 to the torque input member 130. The torque T5 input to the torque output member 140 has its pulsation reduced by the coil spring 148 and the damping orifice member 160 arranged in parallel, and the input of excessive torque is limited.

According to the excessive torque limiting device 120 of the second embodiment described above, the pulsation is reduced by the coil spring 148 and the damping orifice member 160 which are arranged in parallel, and an excessive torque is generated by the torque output member 140. You can limit the output to. As a result, the strength required for the planetary gear 113 connected to the input shaft 112 can be reduced, and the planetary gear 113 can be reduced.
The physique and weight of can be reduced. Of course, the motor 116 and the motor 117 connected to the planetary gear 113 can be protected.

Although the embodiments of the present invention have been described with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible without departing from the gist of the present invention. Of course, it can be implemented in.

[Brief description of drawings]

FIG. 1 is an excessive torque limiting device 2 according to an embodiment of the present invention.
2 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 5 including 0. FIG.

FIG. 2 is a configuration diagram showing an outline of a configuration of an excessive torque limiting device 20 of the embodiment.

FIG. 3 is a schematic diagram schematically showing an excessive torque limiting device 20 of the embodiment.

4 is a torque T1 of the torque input member 30, a torque T2 of the torque transmission member 50, and a torque T of the torque output member 40. FIG.
It is explanatory drawing which shows an example of the time series change of 3.

FIG. 5 is a configuration diagram showing an outline of a configuration of an excessive torque limiting device 120 of a second embodiment.

FIG. 6 is a schematic diagram schematically showing an excessive torque limiting device 120 of a second embodiment.

7 is an explanatory diagram showing an example of a time-series change in torque T4 of the torque input member 130 and torque T5 of the torque output member 140. FIG.

[Explanation of symbols]

5 hybrid vehicles, 9 engines, 10,110
Crankshaft, 12,112 Input shaft, 13,1
13 planetary gears, 14 sun gear shafts, 15 drive shafts, 16,116 motors, 17,117 motors, 1
8 differential gears, 19a, 19b drive wheels,
20,120 Excessive torque limiting device, 30,130 Torque input member, 32,132 Lid member, 34,36,
134, 136 seal member, 40, 140 torque output member, 48, 148 coil spring, 50 torque transmission member, 58 wet friction member, 60, 160 damping orifice member, 62, 162 orifice.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuji Hata             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Kenji Tanabe             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd.

Claims (11)

[Claims] 1. An excessive torque limiting device for transmitting torque from an internal combustion engine to an input shaft of a mechanical mechanism by limiting the excessive torque, the torque input member being connected to an output shaft of the internal combustion engine, A torque transmission member capable of transmitting torque to an input shaft of a mechanical mechanism; a wet friction member arranged in contact with the torque input member and the torque transmission member; and the torque input member and the torque transmission member. An excessive torque limiting device comprising: a compressive stress acting means for applying a predetermined compressive stress to the wet friction member by applying a predetermined force. 2. The excessive torque limiting device according to claim 1, wherein a space in which the wet friction member is arranged is liquid-sealed with a predetermined liquid. 3. The excessive torque limiting device according to claim 1, wherein the torque output member is connected to the input shaft of the mechanical mechanism, and the torque output member and the torque transmitting member are connected to each other to a predetermined distance. An excessive torque limiting device comprising: elastic means for reducing torque pulsation by elasticity of the. 4. The excessive torque limiting device according to claim 3, further comprising a damping unit that is arranged in parallel with the elastic unit and that damps the pulsation of the torque. 5. The excessive torque limiting device according to claim 4, wherein the damping means is a means including at least one orifice. 6. The damping means is a means comprising a liquid that seals a space in which the wet friction member is disposed, and the orifice that allows the liquid to pass therethrough. Over torque limiter. 7. An excessive torque limiting device for transmitting torque from an internal combustion engine to an input shaft of a mechanical mechanism by limiting the excessive torque, the torque input member being connected to an output shaft of the internal combustion engine, A torque output member connected to an input shaft of a mechanical mechanism, elastic means connected to the torque input member and the torque output member for reducing torque pulsation by a predetermined elasticity, and arranged in parallel with the elastic means. An excessive torque limiting device comprising: damping means for damping torque pulsation. 8. The excessive torque limiting device according to claim 7, wherein the damping means is a means including at least one orifice. 9. The damping means is a means including a liquid that seals a space between the torque input member and the torque output member, and the orifice that allows the liquid to pass therethrough. The excessive torque limiting device according to claim 8. 10. The elastic means is a spring.
10. An excessive torque limiting device according to any one of 9 to 9. 11. The gear mechanism according to claim 1, wherein the mechanical mechanism is a gear mechanism having a rotating shaft to which an electric motor or a generator is connected.
11. The excessive torque limiting device according to any one of 1 to 10.