JP3092979B2 - Synchronizer ring made of iron-based sintered alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronizer ring used for a synchromesh type transmission, and more particularly, to an economical, high-strength, high-abrasion-resistant synchronizer with a cone portion of a mating gear. Also relates to a synchronizer ring made of an iron-based sintered alloy.

[0002]

2. Description of the Related Art A synchronizer ring used for a synchromesh meshes with a mating gear, for example, when shifting down from the top to the third, is fitted to the cone of the third gear and fixed to the cone by frictional force. The power is transmitted between the third gear and the output shaft by meshing. Therefore, high strength is required, and for that purpose, high-strength brass has been generally used as the material.

[0003]

In recent years, as the output and weight of the engine have been increased, the load on the transmission has tended to increase. For this reason, a synchronizer ring having higher strength and excellent wear resistance and conformability with a mating gear has been required.

However, the conventional high-strength brass material has already reached its limit in terms of material, and the fact is that no matter how much its composition and shape are improved, it cannot meet the requirements. Further, since the material itself is expensive, it cannot meet the demand for further cost reduction.

[0005] In view of this, it has been considered to use an iron-based sintered alloy having higher strength and better wear resistance than high-strength brass, but such a material results in insufficient adaptability to a mating gear.

[0006] An object of the present invention is to solve such a problem.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a synchronizer ring according to the present invention has a key groove and a key groove .
Into the opposite end face of the corresponding position, to the back of the keyway
To form a recess to reduce the ring wall thickness of the tooth forming portion meshing Nde.

The iron-based sintered alloy used as a material in the present invention contains at least one of Ni, Cu and Mo in an amount of 0.3 to 10 wt% and C in an amount of 0.5 to 1.0 wt%. Desirably, the powder is made by molding and sintering a powder material having a composition consisting of Fe and unavoidable impurities so that the density becomes 7.0 to 7.4 g / cm ³ . In addition, it is desirable to perform any of nitriding, quenching, Cu infiltration, Cu infiltration and nitriding, Cu infiltration and quenching on the key groove portion.

[0009]

[Function] Synchronizer ring made of iron-based sintered alloy,
Since the material itself is inexpensive and does not require machining or the like and is easy to manufacture, cost reduction can be achieved. In addition, when an iron-based sintered alloy, particularly a sintered alloy having the above-described material composition and density, is used, sufficient strength and wear resistance can be ensured. Ni, Cu, and Mo in the material were added to improve strength, toughness, and abrasion resistance, and the added amount was 0.3 wt%.
The following has no effect. Further, even if it is added in an amount of 10 wt% or more, the effect is not extremely enhanced, and it is disadvantageous in terms of economy.

[0010] The reason for limiting the density of 7.0~7.4g / cm ³ is, 7.0 g / cm ³ in the following strength becomes wear resistance insufficient, whereas, at 7.4 g / cm ³ or more This is because it is difficult to form and sinter once. That is, if molding and sintering are performed once with a density of 7.4 g / cm ³ or more, the mold is damaged. Therefore, a process of adding a hot forging process or a process of forming twice and sintering twice is required, which is disadvantageous in terms of manufacturing cost.

Further, if the strength and abrasion resistance are improved by devising the material composition and selecting the density, the rigidity is increased as compared with the conventional product having the same size and shape, and the adaptability to the cone portion of the mating gear is deteriorated, resulting in friction. Although the contact between the surfaces becomes worse, in the present invention, since the concave portion is provided on the end face portion facing the key groove, there is no deterioration in conformability. Due to the presence of the concave portion, the ring cross-sectional area of the key groove forming part is reduced, and although the material strength is increased when the shifting key or hub sleeve presses the synchronizer ring against the cone part of the mating gear, In addition, the ring is easily elastically deformed at the position of the key groove forming portion and adapts to the mating gear, so that the contact with the cone portion becomes uniform, a strong frictional force is generated, and the durability is improved.

The key groove and the concave portion on the end face opposed to the key groove can be easily formed by embossing without resorting to machining according to the powder metallurgy method, which also contributes to cost reduction. Further, when the key groove and the concave portion are embossed and attached to opposing positions, the density of the key groove surface with which the shifting key comes into contact is easily increased, so that the wear resistance of this surface can be further improved.

In addition, treatments such as nitriding, quenching, and Cu infiltration of the key groove surface are effective in preventing fluctuation of the key groove width. In other words, only measures to prevent abrasion by improving the material composition and increasing the density are inadequate, and the keyway surface is worn away, and the width of the keyway fluctuates. It is valid.

[0014]

FIG. 1 shows an embodiment of the present invention. The illustrated synchronizer ring 1 is made by compression-molding and sintering an iron-based powder material having the above-described composition, and has a keyway 2 and teeth 3 that mesh with teeth of a hub sleeve on the outer periphery. It is. In addition, a concave portion 4 is provided on the end face opposite to the position corresponding to the key groove 2 by embossing before sintering to reduce the ring thickness of the meshing tooth forming portion.

The density of the synchronizer ring 1 is adjusted so as to be 7.0 to 7.4 g / cm ³ . In addition, at least in the key groove portion, nitriding, quenching, Cu infiltration, C
Either u infiltration and nitriding, or Cu infiltration and quenching are performed.

FIG. 2 shows a cross section of the key groove installation portion, in which the concave portion 4 extends into the back of the key groove 2 as shown in the figure.
Nde and reduces the ring cross-sectional area of the keyway forming portion (hatched portion), for the elastic deformation of the ring in the portion readily occurs.

Hereinafter, more detailed embodiments will be described. A mixed powder having the composition shown in Table 1 was prepared as a raw material powder, and was compacted at a pressure of 6 to 7 Ton / cm ² .
Then, after sintering the obtained green compact at a temperature of 1100 to 1300 ° C., it was pressed again at a pressure of 6 to 8 Ton / cm ² . Then, at a temperature of 530 to 580 ° C., 1
Gas nitrocarburizing treatment is performed for 0 to 40 minutes (sample No.
1) After immersion in oil for 30 minutes to 1.5 hours at a temperature of 800 to 920 ° C. for 30 minutes to 1.5 hours, followed by quenching, then 160 to 22
Tempering at 0 ° C. was performed (Sample No. 5), only the key groove portion was induction hardened (Sample Nos. 2 and 3), and only the key groove portion was hardened by a carbon dioxide gas laser (Sample No. 4).

Further, at the stage of the green compact, a copper-based infiltrant, which was also green compacted, was brought into contact with the key groove portion, and these were simultaneously sintered and repressurized under the same conditions as the samples No. 1 to No. 5. A ring (Sample No. 6) was also prepared. In each of these, a recess 4 having the same width as the keyway 2 and a depth of about 2.5 mm is formed to reduce the ring thickness of the meshing tooth forming portion to about 2 mm.

On the other hand, for comparison, samples No. 7 to No. 12 (synchronizer rings) which do not satisfy the conditions of the product of the present invention were also prepared. About these, (1)-
The characteristics of (3) were evaluated and compared.

(1) Breaking load of a single body when a taper cone is pressed into a taper hole of a synchronizer ring.

[0021] (2) keyway wear amount by the operation of 3H _Z × 3 hours.

(3) Whether there is a synchro abnormality after the single operation under the conditions of 1400 rpm and 980 N is repeated 5000 times.

[0023]

[Table 1]

As can be seen from the results of the comparative test, the ring of the comparative example is inferior in any of the characteristics, whereas the synchronizer ring of the present invention has excellent strength, abrasion resistance, and conformability with a mating gear. Is shown.

[0025]

As described above, the synchronizer ring according to the present invention is made of an iron-based sintered alloy which is advantageous in terms of material cost and production, while ensuring high strength and high wear resistance while having high rigidity. Deterioration of the compatibility with the mating gear due to the formation of the keyway is prevented by providing a concave portion on the end face on the side opposite to the keyway, and at the same time, wear of the keyway can be suppressed. It is possible to economically cope with the increase and realize a transmission that meets the needs of the times.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a synchronizer ring of the present invention.

FIG. 2 is a cross-sectional view of a keyway forming portion.

[Explanation of symbols]

 1 synchronizer ring 2 keyway 3 meshing teeth 4 recess

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-129304 (JP, A) JP-A 55-78833 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 11/00-23/14

Claims (3)

(57) [Claims] A key is provided on an end face opposite to a position corresponding to a key groove.
-A synchronizer ring made of an iron-based sintered alloy with a recess formed to enter the back of the groove and reduce the ring thickness of the meshing tooth formation portion. 2. A powder material having a composition containing at least one of Ni, Cu and Mo in an amount of 0.3 to 10% by weight, C in an amount of 0.5 to 1.0% by weight, and the balance of Fe and unavoidable impurities. 2. The synchronizer ring made of an iron-based sintered alloy according to claim 1, wherein the synchronizer ring is made by molding and sintering so as to have a density of 7.0 to 7.4 g / cm < ³ >. 3. The iron-based quenching according to claim 1, wherein the key groove portion is subjected to one of nitriding, quenching, Cu infiltration, Cu infiltration and nitriding, Cu infiltration and quenching. Synchronizer ring made of bonded gold.