JPH11230266A - Manufacture of rubber damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber damper manufacturing method that produces more reliable products only through simple working processes. SOLUTION: A damper hub 2 and a smaller mass ring 8 each subjected to rotational balance adjustment in advance and a larger mass ring 6 not specially subjected to such rotational balance adjustment are glued together by vulcanization. The total rotational balance adjustment of a rubber damper 1 thus obtained is thereafter made by the machining of only the larger mass ring 6. The finished rubber damper 1 thus completed has reduced local unbalance in the larger and smaller mass rings 6 and 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber damper for reducing torsional vibration and bending vibration of a rotating shaft, and to a manufacturing method for improving the durability of the product.

[0002]

2. Related Background Art A rubber damper of this kind has a disk-shaped damper hub and a plurality of inertia rings concentrically connected to the damper hub via annular rubber members, respectively. Each of the inertial rings and the rubber members, when attached to the rotary shaft, form a sub-vibration system for the rotary shaft.

As the above-mentioned rubber damper, for example, a damper pulley for reducing torsional vibration and bending vibration generated in a crankshaft of an internal combustion engine is known, and a manufacturing method for this damper pulley is disclosed in Japanese Patent Application Laid-Open No. 62-215145. It has been disclosed. This known manufacturing method fits an outer damper mass assembly around the outer circumference of a pulley hub, and
Based on the outer peripheral surface of the damper mass as a reference, the inner peripheral surface of the boss hole of the pulley hub and the press-fit surface on which the inner damper mass assembly is press-fitted are each machined. And

[0004] A known manufacturing method is to improve the mechanical cutting accuracy, that is, the coaxial accuracy between the inner peripheral surface of the boss hole in the pulley hub and the press-fit surface of the inner damper mass assembly. It is recognized that the amount of eccentricity between the rotation center of the pulley hub and the center of rotation is reduced, thereby obtaining a good rotational balance of the inner damper mass in the damper pulley.

On the other hand, in the rubber damper described above,
The damper hub and the inertia ring are connected via a rubber member, and they are not in a mechanical fitting relationship. For this reason, it is difficult to make the center of rotation of each inertial ring completely coincide with the center of rotation of the damper hub by improving the machining accuracy by simply using a known manufacturing method. Therefore, in the manufacturing process of the rubber damper, an operation process for finally adjusting the rotational balance of the rubber damper as a whole is essential. Specifically, after the inertia ring is vulcanized and bonded to the damper hub, drilling is performed on the inertia ring, and the rotation balance of the rubber damper as a whole is adjusted by reducing its weight.

[0006]

However, even if the rotation balance of the rubber damper as a whole is obtained by the above-mentioned operation, but the rotation balance of each inertial ring is not obtained, when the rubber damper is used, the rotation of the inertia ring is reduced. Unwanted distortion may occur in the rubber member due to the generated centrifugal force. In such a situation, the rotational balance of the rubber damper as a whole is lost due to the displacement of the inertial ring, and the original function of the rubber damper can no longer be exhibited. In this regard, a method of vulcanizing and bonding the inertial rings one by one and adjusting the rotational balance each time can be considered. However, if such vulcanizing bonding is to be performed twice, the first vulcanization is performed. When the rubber member is thermally affected at the time of the second vulcanization, its physical properties are reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain not only the rotational balance of the rubber damper as a whole but also the rotational balance of each inertial ring by a simple operation. It is an object of the present invention to provide a method of manufacturing a rubber damper.

[0008]

According to a first aspect of the present invention, there is provided a method of manufacturing a rubber damper, wherein a rotational balance of a damper hub and an inertia ring other than a maximum diameter is adjusted for each single item in a preparation step. After connecting the inertia ring other than the maximum diameter and the maximum diameter inertia ring whose rotational balance has been adjusted to the damper hub whose rotational balance has been adjusted in the vulcanization bonding process, the inertia ring having the maximum diameter in the balance adjustment process The rotational balance of the rubber damper as a whole is adjusted only by machining the rubber damper.

According to the manufacturing method of the first aspect, the rotational balance of the single damper hub and the inertia ring other than the maximum diameter is adjusted in the preparation step, so that the rubber damper as a whole is obtained after the vulcanization bonding step. The rotational unbalance (unbalance) does not include a single unbalance (local unbalance) included in the inertia ring other than the damper hub and the maximum diameter. Therefore, in the balance adjustment step, the unbalance that simply combines the unbalance of the eccentricity of the center of gravity of the inertia ring other than the maximum diameter with respect to the rotation center of the damper hub and the unbalance included in the inertia ring of the maximum diameter is combined. Is canceled out only by processing into the inertia ring having the largest diameter. As a result, in the finished rubber damper, unbalance (local imbalance) of all the inertia rings in a single product is minimized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a rubber damper will be described below. Referring to FIG. 1, a cross-sectional view of a known rubber damper 1 suitable for a crankshaft of an internal combustion engine is shown as an example. The rubber damper 1 includes a disk-shaped damper hub 2 and a double inertia ring connected to one surface of the damper hub 2 via an annular rubber member 4, that is, a large mass ring 6 and a small mass ring 8. It is a so-called double mass type damper.

The large mass ring 6 and the small mass ring 8 are arranged concentrically, and their centers substantially coincide with the rotation center O of the damper hub 2. As is clear from FIG. 1, the outer diameter of the large mass ring 6 is larger than the outer diameter of the small mass ring 8, and the inertia mass of the large mass ring 6 is set larger. The damper hub 2 has a plurality of bolt holes 10 formed around the rotation center O. The rubber damper 1 is used by being fastened to a crank pulley (not shown) by bolts or the like through the bolt holes 10.

In the rubber damper 1, a damper hub 2
For example, the large mass ring 6 and the small mass ring 8 are formed by press working from a steel sheet blank material, respectively. Here, in the preparatory step of the present invention, preparation is made to adjust the rotational balance for each of the damper hub 2 and the inertia ring other than the maximum diameter, that is, the small mass ring 8 alone. More specifically, the work of adjusting each of the damper hub 2 and the small mass ring 8 so as to include almost no static unbalance is performed.

Of these, the damper hub 2 is formed to have a constant thickness by the above-described sheet metal press working.
The rotation balance of a single product can be easily adjusted. On the other hand, the small mass ring 8 is subjected to processing to reduce the amount of static unbalance included in the small mass ring 8 based on material inhomogeneity at the time of casting and molding dimensional tolerances. The balance around is adjusted. When the damper hub 2 is cast from, for example, an aluminum alloy casting, it is necessary to reduce the amount of unbalance as with the small mass ring 8.

In the next vulcanization bonding step, the damper hub 2 and the small mass ring 8 whose rotational balance has been adjusted in the above-described preparation step, and the large mass ring 6 simply cast and formed.
Is set in a state of being sandwiched between vulcanizing dies (not shown). Then, as well known, a rubber material is injected between the damper hub 2 and the large mass ring 6 and the small mass ring 8 through an injection hole 12 formed in the damper hub 2. As a result, as shown in FIG. 1, the large mass ring 6 and the small mass ring 8 are both connected to the damper hub 2 via the rubber member 4.

In the balance adjusting step, the rotational balance of the rubber damper 1 as a whole is adjusted only by processing the large mass ring 6. Specifically, as described above, by providing the balance adjustment hole 14 at an appropriate position of the large mass ring 6 by drilling, the unbalance of the rubber damper 1 as a whole is removed by reducing the weight.

It should be noted here that the unbalance to be corrected in the balance adjustment step is simply the position of the center of gravity of the small mass ring 8 with respect to the rotation center O of the damper hub 2, that is,
The unbalance between the eccentric centers and the large mass ring 6
The unbalance (local imbalance) of a single product is equal to the combined unbalance. That is, the unbalance (local imbalance) of the damper hub 2 and the small mass ring 8 as a single item is hardly included. Therefore, the rotation balance of the rubber damper 1 as a whole is adjusted only by drilling a hole in the large mass ring 6, and at the same time, unbalance included in the large mass ring 6 alone and unbalance due to eccentricity of the large mass ring 6. Is also mostly removed.

When each of the above steps is performed, the circuit
The rubber damper 1 with the roll balance adjusted is obtained.
You. FIG. 2 shows a large mass when the rubber damper 1 is used.
Centrifugal force f acting on each of the ring 6 and the small mass ring 8₁,
f_TwoShows the relationship. Small mass ring as shown
The centrifugal force generated based on the unbalance of No. 8 is f_Twoage,
Also, it occurs based on the unbalance of the large mass ring 6.
Centrifugal force is f₁Then, these centrifugal forces f₁And f _TwoAre each other
The direction is opposite and the size is equal,
A static rotational balance is established for the entire damper 1.
It is understood that.

However, such centrifugal forces f ₁ and f ₂
When the rubber damper 1 is used, the large mass ring 6 and the small mass ring 8 may be displaced in the radial direction to cause undesired distortion in the rubber member 4, and the centrifugal forces f ₁ and f ₂ in the rubber damper 1 However, it is desirable to keep it as small as possible. The inventor of the present invention has a rubber damper 1.
Attention is paid to the fact that the final unbalance amount of the large mass ring 6 is substantially equal to the unbalance amount of the small mass ring 8.
In order to reduce the amount of unbalance, it has been confirmed that it is effective to reduce the unbalance of the small mass ring 8 in a single step in the preparation process.

Here, the unbalance amount (local unbalance amount) of the small mass ring 8 in the rubber damper 1 is:
As described above, since it is based on the amount of eccentricity of the center position of the small mass ring 8 with respect to the rotation center O of the damper hub 2, the coaxial accuracy when the small mass ring 8 is bonded in the vulcanization bonding step is improved. Thereby, the unbalance amount based on the eccentric amount can be reduced.

On the other hand, the unbalance amount of the large mass ring 6 is
Unbalance small mass ring 8 in balance adjustment process
It has been adjusted to eliminate, and the unbalance of the small mass ring 8
If the volume is reduced, the large mass ring 6
The amount of contact will also be reduced. Refer to FIG.
And large Maslin when the crankshaft speed is constant
And the distortion generated in the rubber member 4
The relationship is shown. For this kind of torsional damper
Therefore, the distortion generated in the rubber member 4 is caused by torsional vibration.
Circumferential distortion λ_fHopefully only
New However, centrifugation based on the unbalance described above
The rubber member 4 is distorted in the radial direction by the force λ. _rMoma
And these distortions λ_f, Λ_rTo the combined distortion
The allowable value is λ when viewed on the vertical axis of FIG._aIs set to
You.

In the horizontal axis shown in FIG. 3, the predetermined value U ₂ of the unbalance in the large mass ring is determined by simply performing vulcanization bonding of the large mass ring and the small mass ring without performing the above-described steps. It shows the maximum value of the unbalance observed for the rubber damper after the balance adjustment. In this case, has occurred is greater than the rubber strain maximum value U ₂ in tolerance lambda _a unbalance, indicating that there is a fear that caused an excessive burden on the rubber member during use of the rubber damper depending on the product.

On the other hand, the predetermined value U _{1 of the} unbalance is
Respect rubber damper 1 obtained by executing the steps of the present invention, has a maximum value of the unbalance in a large mass ring 6, in this case, the rubber distortion caused by the maximum value U ₁ has a tolerance lambda _a It is much lower. Therefore, when the rubber damper 1 is used, no excessive load is applied to the rubber member 4.

According to the inventor of the present invention, by setting the concentricity of the small mass ring 8 set in the vulcanization bonding step to, for example, 0.7 mm or less in diameter, the final large mass ring 6 It has been confirmed that the unbalance can be suppressed to the above-mentioned predetermined value U ₁ . Specifically, it is effective to minimize the clearance between the damper hub 2 and the small mass ring 8 and the vulcanization mold as much as possible, or to suppress deformation of the rubber member 4 after vulcanization bonding. That is, in the method of manufacturing the rubber damper of the present invention, it is important to reduce the amount of unbalance of the small mass ring 8, and the local balance of the large mass ring 6 is also adjusted in the balance adjustment step. The coaxiality of the large mass ring 6 after the vulcanization bonding may be larger than that of the small mass ring 8.
Therefore, it has been confirmed that setting the coaxiality of the large mass ring 6 to, for example, a diameter of 1.0 mm or less is also effective in facilitating the work in the balance adjustment step (balance hole processing work).

Referring now to FIG. 4, there is shown a sectional view of a triple mass type rubber damper 20, and a second embodiment of the rubber damper 20 will be described below. The triple mass type rubber damper 20 has a disk-shaped damper hub 22 and a large mass ring 26 and a small mass ring 28 having the largest diameters connected to one surface of the damper hub 22 via annular rubber members 24, respectively. Further, it has a middle mass ring 32 connected to the other surface of the damper hub 22 via an annular rubber member 30.

In the case of such a triple mass type rubber damper 20, in the preparation step of the above-described embodiment, the rotational balance is adjusted for each of the damper hub 22, the small mass ring 28, and the middle mass ring 32 individually. That is, in addition to the small mass ring 28 other than the large mass ring 26 having the largest diameter,
As for the middle mass ring 32, unbalance (local imbalance) of a single product is reduced.

In the next vulcanization bonding step, the small mass ring 28 and the middle mass ring 32 whose rotational balance has been adjusted, and the large mass ring 26 simply cast are formed on the rubber member 22 whose rotational balance has been adjusted. 24. In the balance adjustment step, the rotational balance of the entire rubber damper 20 is adjusted only by processing the large mass ring 26.

In the case of the second embodiment, the unbalance corrected in the balance adjustment step is, as described above, the unbalance between the eccentricity of the small mass ring 28 and the unbalance of the single large mass ring 26. In addition to the combined unbalance, the unbalance of the eccentricity of the middle mass ring 32 is combined. It is needless to say that even in this case, the unbalance of the damper hub 22, the small mass ring 28 and the middle mass ring 32 alone is hardly included.

When the rubber damper 20 is used, the relationship between the centrifugal forces f ₁ , f ₂ , and f ₃ acting on the large mass ring 26, the small mass ring 28, and the middle mass ring 32 is as follows. centrifugal force f ₁ of the resultant force F and the large mass ring 26 of the centrifugal force f ₃ of the centrifugal force f ₂ and medium mass ring 32 faces to each other is equal opposite magnitude. Even in the second embodiment, the small mass ring 28 and the middle mass ring 32
Each unbalance amount (local imbalance amount)
Can be reduced by increasing the coaxial accuracy of the small mass ring 28 and the middle mass ring 32 in the vulcanization bonding process. Similarly, if the unbalance amount of each of the small mass ring 28 and the middle mass ring 32 is reduced, the unbalance amount of the large mass ring 26 is reduced accordingly.

According to the manufacturing method of each of the above-described embodiments, the amount of local unbalance of the individual inertia rings (large mass, middle mass, and small mass ring) can be reduced, so that the rubber member is used when the rubber damper is used. Therefore, the rubber member can be kept reliable and durable without excessive load. Further, by improving the coaxial accuracy of the small mass ring and the middle mass ring other than the large mass ring, the amount of local unbalance in each inertial ring can be easily reduced.

The small mass ring and the medium mass ring are easier to correct the balance as a single item than the large mass ring having a large outer diameter. On the other hand, the large mass ring has a large inertial mass capacity for adjusting the balance of the entire rubber damper, and has a wide position range for machining the balance adjustment hole. Therefore, more precise balance adjustment can be performed by performing overall balance adjustment by large mass ring. Moreover, it is advantageous in that the rotational balance can be adjusted for the entire rubber damper with less processing.

This manufacturing method does not require a step of correcting unbalance of a large mass ring alone. Therefore, the manufacturing process can be simplified and the production cost can be improved, so that it is very suitable as a manufacturing method for a rubber damper used for a crankshaft of an internal combustion engine, for example. In each of the above-described embodiments, the damper hub is pressed in the preparation process. However, the damper hub may be formed by, for example, a total machining process from a steel material or a sintered alloy process.

The present invention is widely used as a method of manufacturing rubber dampers not only for crankshafts of internal combustion engines, but also for camshafts for valve actuation, drive shafts for fuel injection pumps, and other various rotating shafts that generate torsional vibration. Can be applied.

[0033]

As described above, according to the method of manufacturing the rubber damper of the first aspect, the amount of local unbalance included in the damper hub and the individual inertia rings can be easily reduced, and the product durability can be improved. A high rubber damper can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rubber damper for explaining a manufacturing method according to one embodiment.

FIG. 2 is a model diagram for explaining a rotational balance of a rubber damper.

FIG. 3 is a graph showing a relationship between unbalance of large mass rings and rubber distortion.

FIG. 4 is a sectional view of a rubber damper for explaining a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Rubber damper 2 Damper hub 4 Rubber member 6 Large mass ring (maximum diameter inertia ring) 8 Small mass ring (Inertia ring other than the one having the maximum diameter)

Claims (1)

[Claims] 1. A method of manufacturing a rubber damper having a disk-shaped damper hub and a plurality of inertia rings concentrically connected to the damper hub via rubber members, wherein a maximum diameter of the damper hub and the inertia ring is provided. A preparation step of adjusting the rotational balance for each single piece of the inertial ring other than the one having: and preparing the balance-adjusted inertia ring and the maximum-diameter inertia ring via a rubber material on the balance-adjusted damper hub. A rubber damper manufacturing method, comprising: a vulcanization bonding step of connecting the rubber damper with the rubber damper only by processing the inertia ring having the maximum diameter.