JPH076042B2 - 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.

[Prior Art] Conventionally, a transmission synchronizing ring is generally subjected to intermittent surface contact under high surface pressure with a tapered cone whose inner surface 1 rotates, as illustrated in a perspective view in FIG. 1, and Since the outer peripheral surface has the function of engaging the chamfers 2 provided at predetermined intervals along the outer edge thereof with the chamfer of the hub sleeve, it is required to have strength, wear resistance, and compatibility with the mating member. Therefore, high-strength brass having these characteristics is frequently used in the production thereof. 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% C), 0.1 to 0.9%, Cu or Ni, one or two kinds: 0.2 to 8%, B: 0.02 to 0.5%, and the balance of Fe and inevitable impurities, and 0.05. A nitride layer of 3 to 200 is formed on at least the taper cone friction surface of the Fe-based sintered alloy body having a porosity of ˜5% by volume.
The Fe-based sintered alloy synchronizing ring for transmissions, which is formed with an average layer thickness of μm, has high strength, excellent wear resistance, and compatibility with the mating member, and therefore the high transmission speed. We have obtained the knowledge that it can sufficiently cope with output and weight reduction.

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) 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, while its content exceeds 0.9%. When the toughness is reduced, impact cracking is more likely to occur, and
Since the opponent's aggressiveness will also increase, the content was set to 0.1 to 0.9%.

(B) Ni and Cu These components have the effect of improving the strength, wear resistance, and conformability, but if the content is less than 0.2%, the desired improving effect on the above action is not observed. Even if the content exceeds 8%, no further improvement effect can be obtained, so the content was defined as 0.2 to 8%.

(C) BB component has the effect of improving the toughness and strength as well as improving the sinterability, so if the content is less than 0.02%, the desired effect of the above effect cannot be obtained. If the content exceeds 0.5%, the toughness will decrease, so the content was set to 0.02 to 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 powders, graphite powder, Cu powder, Ni powder, Fe powder, and Fe-B alloy (containing B: 15%) powder each having a particle size of 200 mesh or less are prepared, and these raw material powders are shown in Table 1 respectively. Blended to the blending composition shown in Fig. 1, mixed under normal conditions, and then press-molded into a green compact at a pressure of 5.5 ton / cm ² , and these green compacts are heated at a predetermined temperature within the range of 700 to 900 ° C. After pre-sintering, part of these pre-sintered bodies are warmed to 6-8 tons.
Repressurize using a pressure in the range of / cm ² (The presence or absence of re-pressurization is displayed in the remarks column of Table 1), and then the pre-sintered body and the re-pressurized pre-sintered body in ammonia decomposition gas within the range of 1000 to 1200 ° C. Sintered at a predetermined temperature for 1 hour to form a sintered body having substantially the same composition as the compounded composition, and a part of these sintered bodies has a temperature range of 800 to 1000 ° C. Hot forging was carried out at the temperature inside (the presence or absence of hot forging is indicated in the remarks column of Table 1), and as a result, various porosities shown in Table 1 were also obtained. 5, and 7 to 13, comparative sintered ring 1
As for No. 6 to No. 6, after being immersed in an alkali cyanate composed of cyanate and cyanate at a predetermined temperature within the range of 520 to 580 ° C. for 10 minutes to 5 hours, the temperature within the range of 150 to 300 ° C. An oil-cooled nitriding treatment is performed in oil at a predetermined temperature to form a nitride layer having the average layer thickness shown in Table 1 on the inner surface only.
On the other hand, the sintered ring 6 of the present invention and the comparative sintered ring 7 were subjected to gas soft nitriding treatment in an ammonia atmosphere at a temperature in the range of 520 to 600 ° C. for 3 hours, as shown in FIG. Shape and inner diameter shown in: 58mmφ x thickness 8mm
Fe of the present invention having the dimensions of
Sintered alloy transmission synchronizing rings (hereinafter referred to as the present invention sintered rings) 1 to 13 and comparative Fe-based sintered alloy transmission synchronization rings (hereinafter referred to as the comparative sintered rings) 1 to 7 were manufactured, respectively. .

In the comparative sintered rings 1 to 7, 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 transverse rupture strength was measured for the purpose of evaluating the strength, and the number of revolutions of the taper cone as the mating material was 1000 rpm, the material of the taper cone was the carburized and quenched material of SCM21, the pressing load was 90 kg, and the oil was No. 80 Shion oil, oil temperature: 90 ° C, operation mode of taper cone: 1 second press and 2 second separation, cycle: 7000 cycles, single wear test, and taper cone rotation speed: 1200r.pm, taper Cone pressing load: 50 kg, mating material taper cone and hub sleeve material: S
Carrying and quenching material of CM-21, 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 of initial wear on the inner surface of the ring. In the latter bench test, the presence or absence of abnormal wear of the fabric and the presence or absence of abnormal sound during synchronization 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 13
Have high strength and are excellent in wear resistance and conformability, while the comparative sintered rings 1 to 7
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 …… Chanhua.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C23C 26/00 C F16D 23/06 K

Claims (1)

[Claims] 1. A composition containing C: 0.1 to 0.9%, one or two of Cu and Ni: 0.2 to 8%, B: 0.02 to 0.5%, and the balance Fe and unavoidable impurities ( Fe based sintered alloy having an average layer thickness of 3 to 200 μm formed 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. Synchronous ring for gold transmission.