JPS63227745A - Fe sintered alloy synchronizing ring for transmission - Google Patents

Abstract

PURPOSE:To furthermore improve the strength, wear resistance and conformability by specifying the constituent and porosity of a synchronizing ring and the thickness of an Ni-P compound layer. CONSTITUTION:The titled ring consists of, by weight, 0.1-0.9% C, 0.2-8% Cu and/or Ni, 0.02-0.5% B and the balance Fe, has 0.05-5vol.% porosity and contains the hard Ni-P compound layer having 3-80mu average layer thickness at least on a taper cone friction face 1. In this synchronizing ring, any characteristics among at least the strength, wear resistance and conformability are deteriorated when any requirements of the constitutional requirements are deviated from the above-mentioned areas. Since the titled ring has the high strength, excellent wear resistance and conformability with the mating members, it can sufficiently correspond to the high outputting, thinning accompanied by light weight and miniaturization of a transmission.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a synchronizing ring for a transmission made of an Fe-based sintered alloy that has high strength, excellent wear resistance, and compatibility with a mating member. be.

[Conventional technology]

Conventionally, synchronizing rings for transmissions generally have an inner surface 1 that undergoes intermittent surface contact under high surface pressure with a rotating taper cone, and an outer peripheral surface that is
Since the chamfers 2 provided at predetermined intervals along the outer edge have the function of engaging with the chamfers of the hub sleeve, they are required to have strength, wear resistance, and compatibility with the mating member. High-strength brass with these properties is often used in its manufacture. In addition, there is also a so-called pin type synchronizing ring, which has a thread on the outer circumferential side and rubs against the mating tapered cone on the outer circumferential side.

[Problem that the invention seeks to solve]

However, in recent years, there have been strict demands for higher output and lighter weight for transmissions, and as a result, synchronizer rings are also required to have even higher levels of strength, wear resistance, and conformability. However, the current situation is that conventional high-strength brass bags cannot adequately meet this requirement.

[Means for solving problems]

Therefore, the present inventors conducted research to develop a synchronizing ring for transmissions that can fully meet the above requirements. ), C: 0.1-0.9%, one or both of Cu and Ni = 0.2-8%, B: 0.02-0.5%, with no residue. Hard N is applied to at least the tapered cone friction surface of the Fe-based sintered alloy body, which has a composition consisting of Fe and unavoidable impurities, and a porosity of 0.05 to 5 by volume.
A synchronizing ring for a transmission made of Fe-based sintered alloy, which is formed by forming an i-P compound layer with an average layer thickness of 3 to 80 μm, has high strength and
A mating part with excellent wear resistance.

They found that it has good compatibility with other materials and can therefore be used to increase the output and reduce the weight of transmissions.

Next, in the synchronous ring of the present invention, the reason why the component composition, porosity, and average layer thickness of the Ni--P compound layer are limited to the above-mentioned values will be explained.

(a) CC The C component has the effect of improving strength and wear resistance, but if its content is less than 0.1%, the desired effect cannot be obtained. If it exceeds 9%, the toughness decreases, cracks are more likely to occur due to impact, and the aggressiveness towards opponents increases, so the content was set at 0.1 to 0.9%.

(b) Ni and Cu These components have the effect of improving strength, wear resistance, and conformability, but if their content is less than 0.2%, the desired effect of improving the above effects is not observed. On the other hand, the content was determined to be 0.2 to 8 inches since no further improvement effect could be obtained even if the content exceeded 8 inches.

(C) B In addition to improving sinterability, the B component has the effect of improving toughness and strength, but if its content is less than 0.02%, the desired effect of improving the above effects cannot be obtained, On the other hand, if the content exceeds 0.5 inch, the toughness will decrease, so the content was set at 0.02 to 0.5 inch.

The alloy contains Si, S, and P components as unavoidable impurities, but if the total amount of these components exceeds 0.5%, the strength and toughness will decrease. The content must be kept at 0.5% or less.

B. Porosity The pores in the alloy act as oil reservoirs during practical use, particularly improving the initial conformability of the inner surface of the ring, suppressing the temperature rise of this, and preventing adhesive wear. It has the effect of promoting penetration of the hard Ni-P compound layer, increasing its layer thickness, thereby improving wear resistance, and further normalizing wear by forming a thin oxide film on the pore surface. However, the ratio is 0
．． If the volume is less than 0.05%, the desired effect cannot be obtained, while if the ratio exceeds 31% by volume, the strength will decrease and it cannot be put to practical use. It was set at 5%.

Average layer thickness of the C, Ni-P compound layer If the average layer thickness is less than 3 μm, the desired excellent wear resistance cannot be ensured over a long period of time, while if the average layer thickness exceeds 80 μm, the toughness The average layer thickness was determined to be 3 to 80 μm.

〔Example〕

Next, the synchronization ring of the present invention will be specifically explained using examples.

Graphite powder, Cu powder, Ni powder, Fe powder, and Fe-B alloy (B: 12% content) powder, all of which have a particle size of 200 mesh or less, were prepared as raw material powders, and these raw material powders were After blending with the composition shown in the table and mixing under normal conditions, 5.5tOn/
After press-forming into green compacts at a pressure of c1rL2 and pre-sintering these green compacts at a predetermined temperature within the range of 700 to 900°C, a part of these pre-sintered bodies was heated in a warm state.

6~8tOn/cr! The pre-sintered body and the re-pressed pre-sintered body are then re-pressed using a pressure within the range of A sintered body having substantially the same composition as the compounded composition is formed by sintering in cracked gas at a predetermined temperature within the range of 1000 to 1200°C for 1 hour, and further, these sintered bodies are Some of them are hot forged at a temperature within the range of 800 to 1000℃, and the presence or absence of hot forging is indicated in the remarks column of Table 1), and as a result, various types of After adjusting the porosity, electroless plating was performed by immersion in a plating solution at 90°C to form a Ni-P compound layer with the average layer thickness shown in Table 1 only on the inner surface, and the final By applying heat treatment at a temperature within the range of 350 to 450°C for 0.5 hours, it has the shape shown in Figure 1 and the dimensions of inner diameter: 58Bφ x thickness: 8u, and the number of outer surfaces is reduced. = 32 synchronous rings for transmissions made of Fe-based sintered alloy of the present invention (hereinafter referred to as the sintered rings of the present invention) 1~
13 and comparison synchronizing ring for transmission made of Fe-based sintered alloy (
Samples 1 to 7 (hereinafter referred to as comparative sintered rings) were manufactured, respectively.

Comparative sintered rings 1 to 7 have any of the following conditions (those marked with * in Table 1) of component composition, porosity, and average layer thickness of the Ni-P compound layer according to the present invention. It is outside the range of

Next, regarding the various sintered rings obtained as a result,
The transverse rupture force was measured for the purpose of evaluating the strength, and the rotation speed of the tapered cone, which was the mating material, was 1000 r/p-
Material of the taper cone: 80M21 carburized and quenched material.

For pressing, load = 90 Yu, oil = No. 80 transmission oil, oil temperature: 90°C, taper cone operation mode = 1 second of pressing and 2 seconds of pulling, cycle: 6000 cycles, and a single wear test under the following conditions. Taper cone rotation speed: 1200 r, pm-, Taper cone pressing load: 50 kg, Material of mating taper cone and hub sleeve: SCM-21 carburized and quenched material, Synchronization time = 0.3 seconds to 0.4 seconds (number of times: 50,000 times).

Oil: No. 90 transmission oil, oil temperature near 0℃, Bench test was conducted under the following conditions.In the former single wear test, the presence or absence of cracks in the ring, and the maximum wear amount of the tapered cone friction surface (hereinafter referred to as the inner surface) of the ring were conducted. , the maximum wear amount of the mating material (the maximum wear amounts mentioned above were all shown by the amount of drop prepared by preparing a standard product for measuring the amount of drop), the presence or absence of seizure on the inner surface of the ring, and the initial state of the inner surface of the ring. (up to 500 times) and late (stable period) friction coefficient,
In addition, in the latter bench test, the presence or absence of abnormal wear of the chamfer and the presence or absence of abnormalities during synchronization (abnormal noise, abnormal oil temperature rise) were measured. These results are shown in Table 2.

〔Effect of the invention〕

From the results shown in Table 2, the sintered rings 1 to 13 of the present invention
Comparative sintered rings 1 to 7 all have high strength and excellent wear resistance and conformability.
As seen in the above, it is clear that if any of the constituent features falls outside the scope of the present invention, at least one of the above characteristics will be inferior.

It goes without saying that similar results can be obtained with a pin-type synchronous ring.

As mentioned above, the synchronizing ring for a transmission made of Fe-based sintered alloy of the present invention has high strength, excellent wear resistance, and compatibility with mating parts, so it can increase the output and reduce the weight of the transmission. This makes it possible to satisfactorily cope with the thinning and miniaturization that accompanies this trend.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating a synchronizing ring for a transmission. 1... Tapered cone friction surface (inner surface), 2... Chamfer.

Claims (1)

[Claims] C: 0.1 to 0.9%, one or two of Cu and Ni: 0.2 to 8%
, B: 0.02 to 0.5%, with the remainder consisting of Fe and unavoidable impurities (volume %), and a porosity of 0.05 to 5 volume %. A synchronizing ring for a transmission made of an Fe-based sintered alloy, comprising a hard Ni-P compound layer formed on at least the tapered cone friction surface of the main body with an average layer thickness of 3 to 80 μm.