JPS6336195Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a torsional damper that damps torsional vibrations of a crankshaft of an internal combustion engine. More specifically, the present invention relates to a cooling structure for a torsional damper equipped with two sets of damper units.

[Prior Art] A damper unit of a torsional damper is composed of a damper mounting body fixed to a crankshaft and an annular inertial body fixed to the damper mounting body via an elastic body.

Conventionally, as this type of torsional damper, a ventilation gap is provided between two sets of damper units arranged in parallel in the axial direction of the crankshaft, and fins are provided in this gap to protrude from one of the damper units.
Furthermore, a damper in which a damper mounting body is provided with a ventilation inlet hole communicating with this gap has been disclosed (for example, Japanese Patent Laid-Open No. 54-27668 and Utility Model Laid-Open No. 51-43789).

In a conventional torsional damper, when the crankshaft rotates, air near the damper flows in through the ventilation inlet hole, enters the ventilation gap between the damper units, and is guided by the fins and flows out toward the outer circumference. This results in
The inertial body absorbs torsional vibration energy and radiates heat from the elastic body whose temperature has increased, thereby cooling the elastic body.

[Problems that the invention aims to solve] However, the conventional torsional damper uses the rotation of the fins, which operate in the same way as a centrifugal fan, to
Since the structure is such that air near the damper is sucked in through the ventilation inlet hole, when the rotation of the fins, that is, the rotation of the crankshaft, becomes slow, the cooling capacity is significantly reduced. In addition, since the ventilation inlet hole is installed above the mounting point of the damper mounting body, the hole diameter cannot be increased due to the strength of the damper installation, and there is a natural limit to the amount of ventilation, so it is difficult to increase the cooling capacity. There was a problem that I didn't have.

The purpose of this invention is to provide a cooling structure that increases the amount of airflow between two sets of damper units, has high cooling capacity, prevents overheating of the elastic body, and provides a durable torsional damper. There is a particular thing.

[Means for Solving the Problems] The present invention provides two sets of damper units at the front end of the crankshaft of an internal combustion engine equipped with a cooling fan at the front, spaced apart from each other in the axial direction of the crankshaft. The pulleys are arranged side by side and project forward from their front ends, and the rear ends of pulleys with open front ends are closely attached to the front ends of the damper units, and each damper unit is a damper mounting body fixed to the crankshaft. This is a torsional damper configured with an annular inertial body fixed to this damper mounting body via an elastic body.

Its characteristic feature is that a blowing hole communicating from the inside of the pulley to the space between the damper unit is provided through the damper mounting body radially from the rotation center of the crankshaft, and the blowing hole is radially communicated from the inside of the pulley to the space between the damper unit. The structure is such that air can blow through from the open front end of the pulley, through the inside of the pulley and through the blow-off hole, and between the damper units.

[Function] The pulley acts as a wind guide and guides the air sent by the cooling fan to the blow-off hole, actively allowing the air to pass through even when the torsional damper rotates at low speed, increasing the cooling capacity of the elastic body. You can increase it further.

[Example] Next, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, 10 is a low frequency damper unit, 20 is a high frequency damper unit, 30 is a crankshaft, and 40 is a pulley. The low-frequency damper unit 10 and the high-frequency damper unit 20 are arranged side by side in the axial direction of the crankshaft 30 at intervals, extending forward from the front end thereof. The high frequency damper unit 20 is provided in front of the low frequency damper unit 10. crankshaft 3
A cooling fan (not shown) for the internal combustion engine is arranged in front of the vehicle. The pulley 40 has an open front end and a rear end closely attached to the front end of the high frequency damper unit 20. Air sent by the cooling fan is sent into the inside of the pulley 40.

The low frequency damper unit 10 and the high frequency damper unit 20 are provided with damper mounting bodies 11 and 2, respectively.
1, rubber 12, 22, and annular inertial body 13,
23. The damper attachment body 11 is fitted onto the crankshaft 30, and the damper attachment body 21 and the pulley 40 are integrally attached to the damper attachment body 11 in this order closely with bolts 50. The inertial body 23 is formed to be lighter than the inertial body 13, and a distance t is provided so that the damping action can be performed independently without interfering with each other. These inertial bodies 1
3 and 23 are fixed to one side of the damper mounting bodies 11 and 21, respectively, via rubbers 12 and 22 by vulcanization adhesive so as to face each other. Fins 23a are formed on the side of the inertial body 23 to which the rubber 22 is not bonded.

A characteristic configuration of this embodiment is that, as shown in FIGS. 1 and 2, a blowout hole 60 is provided which communicates from the inside of the pulley 40 to the space between the damper units 10 and 20.
are radially extending through the damper mounting body 21 from the center of rotation of the crankshaft 30.

In a torsional damper having such a configuration, when the internal combustion engine is operated and torsional vibration occurs in the crankshaft 30, if the vibration frequency is low, the torsional vibration is suppressed by the elastic action of the rubber 12 of the low frequency damper unit 10. The vibrations are damped, and in the case of high frequencies, the torsional vibrations are damped by the elastic action of the rubber 22 of the high frequency damper unit 20.

Here, air sent by a cooling fan (not shown) flows from the open front end of the pulley 40 into the cavity inside the pulley 40, as shown by the broken line in the figure, not only when the torsional damper rotates at high speed but also when it rotates at low speed. It is actively introduced, blown out from the blow-off hole 60, and blown through between the damper units 10 and 20.

As a result, the opposing outer surfaces of the damper units 10 and 20 are cooled, and the heat generated by the rubbers 12 and 22 due to internal friction caused by the damping action is taken away and dissipated. Furthermore, since the fins 23a of the inertial body 23 act as a centrifugal fan and actively send air outward from the center of rotation, the cooling capacity is further increased and the ambient temperature of the torsional damper is lowered.

In particular, by providing the high-frequency damper unit 20 in a position in front of the low-frequency damper unit 10, away from the cylinder block of the engine, it is possible to reduce the radiant heat from the engine to the rubber 22, which tends to generate high heat at high vibration frequencies. Even more rubber 2
2. Thermal deterioration can be prevented.

In addition, in the above example, the blow-off hole 6 is provided in the damper mounting body 21.
However, if the lower part of the damper mounting body 11 is located between the damper units 10 and 20, the blowing hole 60 may be provided in the damper mounting body 11. Further, the fins are not limited to the inertial body 23 but may be formed on the inertial body 13.

Figure 3 shows another embodiment of the present invention.
The same symbols as in the figure indicate the same parts. In this example, a damper mounting flange 70 for mounting the damper units 10 and 20 is fitted onto the crankshaft 30. The lower parts of the damper mounting bodies 11 and 12 are disposed on both sides of the flange 70, and the pulley 40
and the damper attachment bodies 11 and 12 are integrally attached to the flange 70 with bolts 50. This flange 70 includes the inside of the pulley 40 and the damper unit 1.
A blowout hole 60 that communicates with the space between 0 and 20 is provided radially through the rotation center of the crankshaft 30.

Since the cooling effect of this embodiment is similar to that of the previous embodiment, repeated explanation will be omitted.

[Effects of the invention] As described above, according to the invention, two sets of damper units are provided projecting from the front end of the crankshaft, and a blowout hole is provided through the mounting body of the damper unit, so that the pulley can be connected to the air guide pipe. By configuring the damper unit so that air can blow through between the damper units, the air sent from the front of the crankshaft is blown into the cavity inside the pulley and then blown out from the outlet, which reduces the elasticity of the damper unit's heating element. It can send in a large amount of air to cool the body.

Further, since the blow-off holes can be widely provided in a portion of the damper mounting body other than the mounting bolts, a large amount of air can pass through without reducing the damper mounting strength. As a result, the torsional damper of the present invention has a high cooling capacity and has an excellent effect of improving the durability of the elastic body.

In particular, by providing fins on one or both of the inertial bodies, the damper unit functions as a centrifugal fan, allowing more efficient cooling.

Furthermore, by installing the high-frequency damper unit in front of the low-frequency damper unit, away from the engine's cylinder block, it is possible to reduce the radiant heat from the engine to the rubber, which tends to generate high heat at high vibration frequencies, making it even more effective. It is possible to further prevent thermal deterioration of the rubber.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a torsional damper according to an embodiment of the present invention. Figure 2 is a cross-sectional view taken along line AA. FIG. 3 is a sectional view of a main part of a torsional damper according to another embodiment of the present invention. 10: Damper unit for low frequency, 20: Damper unit for high frequency, 11, 21: Damper mounting body,
12, 22: rubber, 23: inertial body, 30: crankshaft, 40: pulley, 60: blowout hole.

Claims (1)

[Claims for Utility Model Registration] 1. Two sets of damper units are provided at the front end of a crankshaft of an internal combustion engine equipped with a cooling fan at the front, spaced apart from each other in the axial direction of the crankshaft, and located forward of the front end. The rear ends of the pulleys, which are jutted out and arranged side by side and whose front ends are open, are closely attached to the front ends of the damper units, and each damper unit is connected to a damper mounting body fixed to the crankshaft and the damper mounting body. A torsional damper is constituted by an annular inertial body fixed via an elastic body, and the blowing hole communicating from the inside of the pulley to the space between the damper unit is radially extending from the rotation center of the crankshaft. The cooling fan is installed through the damper mounting body so that air sent by the cooling fan blows between the damper units from the open front end of the pulley through the inside of the pulley and the blow-off hole. Features a torsional damper cooling structure. 2. Two sets of damper units are composed of a high-frequency damper unit and a low-frequency damper unit, and the high-frequency damper unit is provided in a position in front of the low-frequency damper unit. Cooling structure of the described torsional damper.