JPH01252744A - Synchronous ring for transmission made of Cu-based sintered alloy - Google Patents

Abstract

PURPOSE:To provide superior initial conformability and excellent wear resistance over a long period by specifying respective contents of Zn, Al, Si, and Mn in a sintered Cu alloy and also specifying the porosity of pores in a sliding surface. CONSTITUTION:A sintered alloy has a composition consisting of, by weight, 10-40% Zn, 1.5-8% Al, 0.2-3.5% Si, 0.1-8% Mn, and the balance Cu with inevitable impurities. Further, 0.1-4% Sn and 0.1-4% of one or more elements among Ti, Zr, V, and Cr are incorporated to the above composition, if necessary. Moreover, pores of 0.05-5vol.% porosity are allowed to exist at least in the contact sliding surface with a mating member after sintering. A synchronous ring made of the above sintered alloy combines high strength with high toughness and particularly has superior initial conformability and, further, this ring shows excellent wear resistance over a long period at the time of practical use under severe conditions attendant upon the increasing output of a gearbox.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a transmission made of a Cu-based sintered alloy, which has particularly excellent initial conformability of the contact sliding surface with a mating member and excellent wear resistance. This relates to a synchronization ring.

[Conventional technology]

Conventionally, a synchronizing ring for a transmission generally has an inner surface 1 that serves as a contact sliding surface with a rotating taper cone, and a tapered cone serving as a mating member on this contact sliding surface, as illustrated in a perspective view in FIG. are intermittently in surface contact under high surface pressure, and a key groove 3 into which a key fits is formed on the unilateral peripheral surface, and further,
Since the chamfers 2 provided at predetermined intervals along the outer edge have the function of engaging with the chamfers of the hub sleeve, which is also a mating member, they are required to have strength, wear resistance, and compatibility with the mating member. , therefore, high-strength brass with these characteristics 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 a tapered cone, which is a mating member, on the outer circumferential side.

[Problem to be solved by the invention]

However, with the increase in the output of transmissions in recent years, the above-mentioned conventional high-strength brass synchronizing ring has become more difficult to connect with at least one of the mating members of the above-mentioned taper cone, key, and chamfer of the hub sleeve. Since the contact sliding surface is subjected to high surface pressure, initial conformability decreases, which leads to frequent abnormal wear such as bright surface wear and adhesive wear, leading to a shortened service life. ing.

[Means to solve the problem]

Therefore, the present inventors conducted research to solve the problems of the conventional high-strength brass synchronizing ring for transmissions as described above, and as a result, Z Mouth=10-40%, l:1.
5-8%.

St: 0.2-3.5%, Mn: O, I ~
8%.

Contains, and if necessary, Sn: 0.1 to 4%.

One or more of Ti, Zr, V and Cr: 0.05 to 4%.

Consisting of a Cu-based sintered alloy containing either or both of the following, with the remainder consisting of Cu and unavoidable impurities,
In addition, at the required locations of the contact sliding surface with the mating member, that is, the taper cone, the key, and the chamfer of the hub sleeve, at least one of the contact sliding surfaces with the mating member has a porosity of 0.05 to 0.05. 5% by volume.

Synchronizing rings for transmissions made of Cu-based sintered alloys, which contain pores, exhibit excellent initial conformability even under conditions of use under high surface pressure associated with the high output of transmissions, and prevent abnormal wear in the early stages of use. They obtained the knowledge that the occurrence of this disease was suppressed.

This invention has been made based on the above findings, and the reason why the component composition and porosity are limited as described above will be explained.

(a) Zn and Aj7 These components determine the base structure of the alloy, improve the wear resistance of the base, provide the strength and toughness necessary for the synchronous ring, and further improve fatigue strength and yield strength. It is a component that has excellent properties and prevents adhesion (seizure) due to plastic flow caused by local high-temperature heating, thereby preventing initial abnormal wear and improving initial conformability in oil pools. When the content is less than 10% and Aj): less than 1.5%, it is not only impossible to ensure the above properties, but also it becomes difficult to form a work-hardened layer having the above properties; The amount is Zn: 40% and Ail
: If it exceeds 8%, the toughness will decrease, so the content should be adjusted to Zn: 10-40% and Ag: 1.5-8.
%.

(b) St and Mn These components have 1. Forms intermetallic compounds that are finely dispersed in the base material, improving the strength and toughness of the ring, as well as improving wear resistance, and improving conformability and seizure resistance. However, if the content exceeds Sl: 3.5% and Mn: 8%, the desired effect cannot be obtained. Also, since there is no effect of the − layer, its content is reduced to Sl
: 0.2 to 3.5%, Mn: 0.1 to 8%.

(c) The 5n Sn component has the effect of preventing adhesive wear and ensuring excellent anti-seizure properties, so it is included as necessary, but the content is less than 0.1%. However, even if the content exceeds 4%, there is no effect of the - layer, so the content is reduced to 0.
．． It was set at 1 to 4%.

(d) TI, Zr, V and Cr In these components, the Mn-3L intermetallic compound dispersed in the substrate is made into fine spherules, and they themselves form a composite compound with Mn and Sl to increase strength. .

Since it has the effect of improving toughness and wear resistance, it is included as necessary, but if the content is less than 0.1%, the desired effect of improving the above effects cannot be obtained; Even if it exceeds 4%, no further improvement effect will be obtained, so in consideration of economic efficiency, the content was set at 0.1 to 4%.

In addition, unavoidable impurities such as P, Pb1, and Mg may be contained, but if the total amount of these unavoidable impurities is 1.5% or less, they will not affect the properties in any way, so the content The content is allowed within the range of 1.5% or less.

(e) Porosity The pores in the alloy become oil pockets during practical use, which improves the initial conformability of the inner surface of the ring, suppresses the temperature rise of this, and prevents adhesive wear. It has the effect of improving wear resistance and normalizing wear by forming a thin oxide film on the pore surface, but if the proportion is less than 0.05% by volume, the desired effect cannot be obtained. On the other hand, if the proportion exceeds 5% by volume, the strength decreases and it becomes impossible to put it into practical use, so the proportion was set at 0.05 to 5%.

〔Example〕

Next, the synchronizing ring for a transmission made of a Cu-based sintered alloy according to the present invention will be specifically described with reference to examples.

Raw material powders include Cu powder, Zn powder, Ag powder, TI powder, and Z powder, all of which have a particle size of 200n+esh or less.
r powder, ■ powder, Sn powder, Sl powder.

Prepare Mn powder and Cr powder, blend these raw material powders into the composition shown in Table 1, mix them under normal conditions, and then press-form with a pressure crab at 4 ton/c to form a compacted powder. These green compacts are 450
Preliminary sintered bodies are produced by pre-sintering at a predetermined temperature within the range of ℃~700℃, and these pre-sintered bodies are heated to (A) 550℃.
A method of hot forging at a predetermined temperature within the range of ~850°C, (B) A method of sintering in an H2 gas atmosphere at a predetermined temperature within the range of 850°C ~ 900°C, (C) A method of sintering at a predetermined temperature within the range of 850°C ~ 900°C. The first method is to perform hot forging at a predetermined temperature within a range of 550°C to 850°C after sintering in an H2 gas atmosphere at a predetermined temperature within a range of 900°C. Made of Cu-based sintered alloy with porosity shown in Examples 1 to 20 of the present invention and Comparative Examples 1 to 8 in the table, inner diameter: 50 m + * thickness: 3 mm, and number of chamfers: 24. Synchronous rings for transmissions (hereinafter referred to as synchronized rings) were manufactured.

In addition, in the comparative example, any of the conditions of the component composition and porosity of the synchronization ring are outside the scope of the present invention, and the above conditions are indicated with an asterisk in Table 1. Indicated.

Using the above synchronization ring, the rotation speed of the tapered cone, which is the mating member, is 211100r,
p,i,.

Load for pressing: 50 kg.

Oil type = No. 80 gear oil.

Oil temperature: 60℃.

Taper cone operation 20,000 times with synchronization time of 0.4 to 0.5 seconds.

A synchro durability test was conducted under the following conditions, and the amount of depression (amount of wear) on the inner surface of the synchronizer ring, the presence or absence of adhesive wear, and the initial (
The friction coefficient, cracking, and deformation of the ring were measured and observed (up to 500 times) and later (stable period), and the results are shown in Table 2.

〔Effect of the invention〕

From the results shown in Tables 1 and 2, the Cu-based sintered alloy synchronous ring of the example of the present invention has excellent conformability in the early stage of practical use despite high surface pressure conditions, and does not cause abnormal wear. It showed excellent wear resistance, and the strength, which is considered to be a weak point of Cu-based sintered alloys, was found to be sufficiently strong as a synchronous ring for a transmission based on the results of the above test.

On the other hand, as seen in the comparative examples in Tables 1 and 2, if any of the constituent elements falls outside the scope of the present invention, at least one of the above characteristics will fail. It is clear that it 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 a Cu-based sintered alloy of the present invention has high strength and toughness, has particularly good initial conformability, and can withstand harsh conditions such as 1+ for increasing the output of a transmission. Even in practical use, there is no occurrence of abnormal wear such as bright surface wear or adhesive wear, and it exhibits excellent wear resistance for an extremely long period of time.

[Brief explanation of the drawing]

FIG. 1 is a perspective view illustrating a synchronizing ring for a transmission. 1... Tapered cone friction surface (inner surface), 2... Chamfer, 3... Keyway.

Claims (4)

[Claims] (1) Zn: 10-40%, Al: 1.5-8%, Si
: 0.2 to 3.5%, Mn: 0.1 to 8%,
Composition with the remainder consisting of Cu and unavoidable impurities (more than % by weight)
is made of a Cu-based sintered alloy having a porosity of 0.05 to 5% by volume at least on the sliding surface that contacts the mating member.
A synchronous ring for a transmission made of a Cu-based sintered alloy, characterized by the presence of pores. (2) Zn: 10-40%, Al: 1.5-8%, Si
: 0.2 to 3.5%, Mn: 0.1 to 8%,
Furthermore, it is composed of a Cu-based sintered alloy having a composition (the above weight %) containing Sn: 0.1 to 4%, and the remainder consisting of Cu and unavoidable impurities, and
Porosity: 0.05 at least on the contact sliding surface with the mating member
A synchronous ring for a transmission made of a Cu-based sintered alloy, characterized by the presence of pores of ~5% by volume. (3) Zn: 10-40%, Al: 1.5-8%, Si
: 0.2 to 3.5%, Mn: 0.1 to 8%,
Furthermore, one or more of Ti, Zr, V and Cr:
0.1 to 4%, and the remainder is Cu and unavoidable impurities (weight%), and
Porosity: 0.05 at least on the contact sliding surface with the mating member
A synchronous ring for a transmission made of a Cu-based sintered alloy, characterized by the presence of pores of ~5% by volume. (4) Zn: 10-40%, Al: 1.5-8%, Si
: 0.2 to 3.5%, Mn: 0.1 to 8%,
Furthermore, Sn: 0.1 to 4%, and one or more of Ti, Zr, V, and Cr:
0.1 to 4%, and the remainder is Cu and unavoidable impurities (weight%), and
Porosity: 0.05 at least on the contact sliding surface with the mating member
A synchronous ring for a transmission made of a Cu-based sintered alloy, characterized by the presence of pores of ~5% by volume.