JPH076040B2 - Fe-based sintered alloy transmission synchronization ring - Google Patents

Description

TECHNICAL FIELD The present invention relates to a Fe-based sintered alloy transmission synchronizing ring having high strength, excellent wear resistance, and compatibility with a mating member. is there.

[Conventional technology]

Conventionally, generally, a transmission synchronizing ring is subjected to intermittent surface contact under high surface pressure with a tapered cone whose inner surface 1 rotates, as shown in a perspective view in FIG.
Since the chamfers 2 provided at predetermined intervals along the outer edge thereof have a function of engaging with the chamfers of the hub sleeve, it is required to have strength, wear resistance, and compatibility with a mating member. High-strength brass having these characteristics is often used in its manufacture. In addition to the above, there is a so-called pin type of synchronizing ring in which a screw is provided on the outer peripheral side and rubs against a mating taper cone on the outer peripheral side.

[Problems to be solved by the invention]

However, in recent years, demands for higher output and lighter weight of transmissions have become strict, and accordingly, further higher strength, wear resistance, and conformability have also been required for the synchronizing ring. However, the current situation is that conventional high strength brass products cannot sufficiently cope with this.

[Means for solving problems]

Therefore, the inventors of the present invention have conducted research to develop a transmission synchronization ring that can sufficiently meet the above-mentioned requirements, and as a result, the weight% (hereinafter,% relating to the component composition is the weight% Shown), one or more of Mn, Cr, and Mo: 0.1 to 6
%, C: 0.1 to 0.9%, and, if necessary, one or two of Ni and Cu: 0.1 to 6%, and B: 0.
02-0.5%, a composition containing either or both, and 0.05-
A Fe-based sintered alloy transmission synchronizing ring formed by forming a nitride layer with an average layer thickness of 3 to 200 μm on at least a taper cone friction surface of a Fe-based sintered alloy body having a porosity of 5% by volume. It has been found that it has high strength, excellent wear resistance, and compatibility with a mating member, and therefore can sufficiently cope with higher output and lighter weight of the transmission.

Next, in the synchronizing ring of the present invention, the reasons why the component composition, the porosity, and the average layer thickness of the nitride layer are limited as described above will be described.

A. Component composition (a) Mn, Cr, and Mo These components improve strength and toughness,
Improves wear resistance and further reacts with a part of the nitrided layer to improve seizure resistance.Since these components are easily oxidized, wear is normalized by a micro oxidation phenomenon during practical use. And, there is an effect of preventing seizure, but if the content is less than 0.1%, the desired effect cannot be obtained, and if the content exceeds 6%, no further improvement effect appears. Therefore, in consideration of economic efficiency, the content is set to 0.1 to 6%.

(B) CC component has an effect of improving strength and wear resistance, but if its content is less than 0.1%, the desired effect cannot be obtained on the other hand, while its content exceeds 0.9%. Toughness decreases, and cracks due to impact are more likely to occur,
Since the opponent's aggressiveness will also increase, the content was set to 0.1 to 0.9%.

(C) Ni and Cu These components have the effect of improving the strength, wear resistance and conformability, so they are contained as necessary, but if the content is less than 0.1%, they are desirable for the above-mentioned action. However, even if the content exceeds 6%, no further improvement effect can be obtained.
It was set at ~ 6%.

(D) BB The B component has an effect of improving the toughness and strength as well as improving the sinterability, so it is contained as necessary. However, if the content is less than 0.02%, the desired effect is improved in the above function. If the effect is not obtained and the content exceeds 0.5%,
Since the toughness is reduced, its content is 0.02
It was set at ~ 0.5%.

Although Si, S, and P components are contained as unavoidable impurities, if these components exceed 0.5% in total, strength and toughness will decrease, so the total amount will be The content must be 0.5% or less.

B. Porosity Porosity in the alloy acts as an oil reservoir during practical use, especially to improve the initial conformability of the inner surface of the ring and to suppress the temperature rise of this to prevent cohesive wear. It has the effect of promoting the permeation of the layer, increasing the layer thickness, and thus improving the wear resistance, and further forming a thin oxide film on the pore surface to normalize the wear, but the ratio is If it is less than 0.05% by volume, the desired effect cannot be obtained, while if it exceeds 5% by volume, the strength decreases and it cannot be put to practical use. Therefore, the ratio is set to 0.05 to 5%. Specified.

C. Average Layer Thickness of Nitrided Layer If the average layer thickness is less than 3 μm, desired excellent wear resistance cannot be ensured for a long time, while if the average layer thickness exceeds 200 μm, toughness decreases. Therefore, the average layer thickness was determined to be 3 to 200 μm.

〔Example〕

Next, the synchronizing ring of the present invention will be specifically described by way of examples.

As raw material powder, graphite powder, Cu powder, Fe powder, Mo powder, Cr powder, Mn powder, Ni powder, Fe-B alloy (B: 12% content) powder, Fe-Mn, each having a particle size of 200 mesh or less Prepare alloy (Mn: 30% content) powder and Fe-Cr alloy (Cr: 15% content) powder, mix each of these raw material powders with the composition shown in Table 1, and mix under normal conditions. After that, it is press-molded into a green compact at a pressure of 5.5 ton / cm ² , and these green compacts are pre-sintered at a predetermined temperature within the range of 700 to 900 ° C. Is re-pressurized using a pressure within the range of 6 to 8 ton / cm ² at warm temperature (indicates whether or not re-pressurization is performed in the remarks column of Table 1), and then the temporary sintered body and the The re-pressurized pre-sintered body in 1000 to 12
Sintering is performed at a predetermined temperature within the range of 00 ° C. for 1 hour to form a sintered body having substantially the same composition as the compounding composition, and further, a part of these sintered bodies is Performed hot forging at a temperature within the range of 800 to 1000 ° C (indicate the presence or absence of hot forging in the remarks column of Table 1), As a result, the various porosities shown in Table 1 are similarly obtained, and the sintered rings 1 to 5, 7, 8 and 10 to 22 of the present invention,
For comparative sinter rings 1 to 3, and 5, the sinter ring was subsequently placed in an alkali cyanate consisting of cyanide and cyanate.
After immersing at a predetermined temperature within the range of 0 to 580 ° C for 10 minutes to 5 hours, oil-cooled nitriding treatment is performed in oil at the predetermined temperature within the range of 150 to 300 ° C, and only the inner surface is also subjected to the first A nitride layer having an average layer thickness shown in the table is formed, while the sintered rings 6 and 9 of the present invention and the comparative sintered rings 4 and 6 have a temperature in the range of 520 to 600 ° C. By performing the gas soft nitriding treatment under the condition of holding for 5 hours, the Fe system of the present invention having the shape and inner diameter: 58 mmφ × thickness: 8 mm shown in FIG. Sintered alloy transmission synchronization ring (hereinafter referred to as "sintered ring of the present invention")
1 to 22 and comparative Fe-based sintered alloy transmission synchronizing rings (hereinafter referred to as comparative sintered rings) 1 to 6 were manufactured.

In the comparative sintered rings 1 to 6, any one of the component composition, the porosity, and the average layer thickness of the nitrided layer (marked with * in Table 1) is within the range of the present invention. It's off.

Next, regarding the various sintered rings obtained as a result,
The resistance force was measured for the purpose of evaluating the strength, and the number of revolutions of the counterpart cone, the taper cone: 1000 rpm, the material of this taper cone: the carburized and quenched material of SCM21, the pressing load: 100 kg, the oil: No. 90 mesh Oil, oil temperature: 120 ° C, taper cone operation mode: 1 second push and 2 second release, cycle: 6000 cycles, single wear test, and taper cone speed: 1200r.pm, taper cone Pressing load: 50 kg, mating material taper cone and hub sleeve material: S
CM-21 carburized and hardened material, synchronization time: 0.3 seconds to 0.4 seconds (number of times: 50,000 times), oil: No. 90 mixture oil, oil temperature: 70 ° C, bench test was conducted under the conditions of the former single unit In the wear test, the ring has cracks, the maximum wear amount of the tapered cone friction surface of the ring (hereinafter referred to as the inner surface), and the maximum wear amount of the mating material (the maximum wear amounts are all standard products for measuring the amount of depression). Was prepared, and the amount of the drop was shown.), The presence or absence of seizure on the inner surface of the ring, the coefficient of friction of the inner surface of the ring (up to 500 times) and the latter period (stable phase), and the presence or absence of initial wear on the inner surface of the ring. In the latter bench test, the presence or absence of abnormal wear of the changhua and the presence or absence of abnormalities during synchronization (abnormal sound, abnormal oil temperature rise) were measured. The results are shown in Table 2.

〔The invention's effect〕

From the results shown in Table 2, the present invention sintered rings 1 to 22
Have high strength and are excellent in wear resistance and conformability, on the other hand, comparative sintered rings 1 to 6
As can be seen from the above, when any of the constituents is out of the scope of the present invention, it is clear that at least one of the above characteristics becomes inferior. Needless to say, the same result can be obtained with a pin type synchronizing ring.

As described above, since the Fe-based sintered alloy transmission synchronizing ring of the present invention has high strength, excellent wear resistance, and compatibility with a mating member, the transmission has high output and light weight. Therefore, it is possible to fully satisfy the requirements for thinning and downsizing.

[Brief description of drawings]

 FIG. 1 is a perspective view illustrating a transmission synchronization ring. 1 …… Tapered cone friction surface (inner surface), 2 …… Changhua.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C23C 26/00 C F16D 23/06 K

Claims (4)

[Claims] 1. A composition containing one or more of Mn, Cr, and Mo: 0.1 to 6%, C: 0.1 to 0.9%, and the balance Fe and unavoidable impurities (more than wt%). ), And a Fe-based sintered alloy transmission formed by forming a nitride layer with an average layer thickness of 3 to 200 μm on at least the tapered cone friction surface of the Fe-based sintered alloy body having a porosity of 0.05 to 5% by volume. Sync ring for aircraft. 2. One or more of Mn, Cr, and Mo: 0.1 to 6%, C: 0.1 to 0.9%, and one or two of Ni and Cu. : 0.1 to 6%, the balance consisting of Fe and unavoidable impurities (more than wt%), and a porosity of 0.05 to 5% by volume on at least the taper cone friction surface of the Fe-based sintered alloy body. , A ferrous sintered alloy transmission synchronizing ring made of a nitride layer having an average layer thickness of 3 to 200 μm. 3. One or more of Mn, Cr, and Mo: 0.1 to 6%, C: 0.1 to 0.9%, and further B: 0.02 to 0.5%. A composition comprising the balance of Fe and unavoidable impurities (more than weight%) and a porosity of 0.05 to 5% by volume on at least the taper cone friction surface of the Fe-based sintered alloy body, a nitride layer having an average layer thickness of 3 to 200 μm. Synchronous ring for transmission made of Fe-based sintered alloy, which is made thick. 4. One or more of Mn, Cr, and Mo: 0.1 to 6%, C: 0.1 to 0.9%, and one or two of Ni and Cu. : 0.1 to 6%, B: 0.02 to 0.5%, the balance consisting of Fe and unavoidable impurities (there is more than weight%), and a porosity of 0.05 to 5% by volume 1. A Fe-based sintered alloy transmission synchronizing ring for transmission, comprising a nitride layer having an average layer thickness of 3 to 200 μm formed on at least the tapered cone friction surface.