JPS63238255A - Synchronous ring for change gear made of cu alloy - Google Patents

Abstract

PURPOSE:To obtain a synchronous ring for a change gear having superior initial fitness and wear resistance by forming an Al2O3-based oxide layer of a specified thickness on the contact surface of a ring made of a Cu alloy having a specified compsn. consisting of Zn, Al, Ti, Zr, Sn and Cu. CONSTITUTION:A synchronous ring for a change gear is made of a Cu alloy having a compsn. consisting of, by weight, 20-40% Zn, 2-8% Al, 0.1-3% Ti and/or Zr and the balance Cu with inevitable impurities or further contg. 0.1-5% Mn. An Al2O3-based oxide layer of 0.1-10mum average thickness is then formed on the desired part of the contact surface of the ring brought into contact with the opposite member. Thus, a synchronous ring for a change gear made of the Cu alloy and having high strength and toughness is obtd. The contact surface has superior initial fitness and exhibits such superior wear resistance that abnormal wear is not caused.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a synchronizing ring for a transmission made of a Cu-based alloy, which has particularly excellent initial conformability of the contact surface with a mating member and excellent wear resistance. It is something.

[Conventional technology]

Conventionally, a synchronizing ring for a transmission generally has an inner surface 1 that is in contact with a rotating tapered cone, and a tapered cone serving as a mating member on this abutting surface, as illustrated in a perspective view in FIG. are intermittently in surface contact under high surface pressure, - A key groove 3 into which a key fits is formed on the peripheral surface of the Mansaku, and chamfers 2 provided at predetermined intervals along the outer edge of the key groove 3 are also provided with chamfers 2 provided at predetermined intervals along the outer edge of the key groove 3. Since it has the function of interlocking with the chamfer of the barrel hub sleeve, it is required to have strength, wear resistance, and compatibility with the mating member, so high-strength brass with these characteristics is used for manufacturing. It is widely used. 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, as the output of transmissions has increased in recent years, the above-mentioned conventional high-strength brass synchronizing ring has been designed to reduce the The contact surface with at least one of the mating parts will be subjected to high surface pressure, which will reduce the initial conformability and cause frequent abnormal wear such as bright part wear and adhesive wear. , which causes a shortened service life.

[Failure 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 found that Zn :20-40%, AA:2-8%, T1 and Z
One or two of r = 0.1 to 3.

Sn: 0.1-3%.

and, if necessary, Mn:O, 1 to 5%, and the rest is Cu and unavoidable impurities. An oxide film layer mainly composed of aluminum oxide (A1205) with an average thickness of 0.1 to 10 μm is applied to the required locations, that is, on the surface that contacts the mating member of at least one of the taper cone, key, and chamfer of the hub sleeve. The synchronizing ring for transmissions made of a thick Cu alloy exhibits excellent initial conformability even under conditions of use under high surface pressure associated with the increase in the output of transmissions, and suppresses the occurrence of abnormal wear in the early stages of use. We have obtained the knowledge that it becomes possible to

This invention has been made based on the above knowledge, and the reason why the component composition and the average layer thickness of the oxide film layer are limited to the above-mentioned standard will be explained.

(a) Zn and M 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 the initial conformability. An oxide film layer that is good and prevents bright part wear due to metal-to-metal wear and seizure phenomenon due to adhesion, that is, Al2O3-Zn02 based mainly on Al2O3 or Al2O5-ZnO.
It is an essential component for forming a 2-CuO-based oxide film layer on the ring surface, but if the content is less than 20% for Zn and less than 2% for fii, the desired characteristics and oxide film layer cannot be secured. On the other hand, the content is Zn:4
If the content exceeds Zn: 0% and M: 8%, the toughness will decrease, so the content should be adjusted to Zn: 20 to 4%.
0%, M: 2 to 8%.

(b) Ti and Zr and 5n T1 and/or Zr and Sn coexist,
In addition to making the crystal grains finer, it also forms intermetallic compounds that are finely dispersed in the base material to improve strength and toughness, as well as wear resistance. have the effect of improving wear resistance, but if the content is less than 0.1% each, the desired effect cannot be obtained, while if the content exceeds 3% each, the toughness decreases. Therefore, the content is
Ti and/or Zr: 0.1-3%, Sn: O
, '1 to 3%, respectively.

(c) Mn The Mn component has the effect of forming a solid solution in the base material and strengthening it, as well as making intermetallic compounds into fine spherules, thereby improving wear resistance, so it may be included as necessary. If the content is less than 0.11, the desired effect of improving the above action cannot be obtained, and on the other hand, if the content exceeds 5, no further improvement effect is obtained, and instead, more slag is generated during melting. Therefore, the content was determined to be 0.1 to 5.

In addition, unavoidable impurities such as P, Pb, and even Mg may be contained, but if the total amount of these unavoidable impurities is 1% or less, they will not affect the characteristics in any way, so the total amount The content is allowed within the range of 1% or less.

(d) Oxide film layer The oxide film layer has many microscopically small bores, and in practical use, these bores act as oil reservoirs to improve initial conformability, and the rings make frictional contact during synchronization. However, since this oxide film layer has low thermal conductivity, it has the effect of suppressing the temperature rise to the inside of the ring body. It has the effect of promoting normal wear without causing abnormal wear such as partial wear or adhesive wear, but if the average layer thickness is less than 0.1 μm, the desired effect cannot be obtained; When the thickness exceeds 10 μm, chipping and peeling tend to occur, so the average layer thickness was set at 0.1 to 10 μm.

〔Example〕

Next, the synchronization ring of the present invention will be described in detail with reference to embodiments.

Using an ordinary high-frequency furnace, CU-based alloy melts having the compositions shown in Table 1 were prepared, and mold casting was carried out.
A billet with a diameter of 200 mm and a length of 400 H was formed, and this billet was extruded into a round bar with a diameter of 60 Bφ using an extrusion press, and the round bar was cut into a predetermined length. Hot forging is carried out at a temperature within the range of ~750°C, further cutting is performed, and then the temperature is heated to 100°C in the atmosphere.
By heating to a predetermined temperature within the range of 35.0 ° C. for a predetermined time within the range of 15 minutes to 6 hours, and forming an oxide film layer on the entire surface with the average layer thickness shown in Table 1, Synchronous rings 1 to 14 of the present invention and comparative synchronous rings 1 to 10 each having dimensions of inner diameter: 5B1tlEφ x thickness = 4B and number of chamfers of 36 were manufactured.

Note that Comparative Synchronization Rings 1 to 10 have any of the conditions (those marked * in Table 1) of the component composition and average layer thickness of the oxide film layer that are outside the scope of the present invention. .

Next, regarding the various synchronization rings obtained as a result, the rotation speed of the tapered cone, which is the mating member: 1000 r,
p, m-.

A synchro durability test was conducted under the following conditions: Load: 50 Yu, Oil: No. 80 transmission oil, Oil temperature near 0℃, Taper cone operation: 20,000 times with a synchronization time of 0.25 to 0.3 seconds. Amount of depression (amount of wear) on the inner surface, presence or absence of adhesive wear.

The initial (up to 500 times) and late (stable period) friction coefficients were measured and observed, respectively.

Taper co-y (7), which is the mating member, rotation speed: 2oo.

r, p, m,, Load for pressing: 90kg.

Oil: No. 80 transmission oil, oil temperature near 0℃, taper cone operation 20, 5000 times with synchronized time of 25 to 0.3 seconds.

A synchro durability test was conducted under the following conditions, and the presence or absence of cracks and deformation in the ring was observed. These results are shown in Table 1.

〔Effect of the invention〕

From the results shown in Table 1, the synchronization rings 1 to 14 of the present invention
Both have high strength and toughness, and exhibit excellent conformability in the initial stage of practical use, no abnormal wear, and excellent wear resistance, even under high surface pressure conditions. As seen in Comparative Synchronization Rings 1 to 10, it is clear that if any of the constituent requirements 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 Cu-based alloy synchronizing ring for transmissions of the present invention has high strength and toughness, and is particularly good in initial conformability, making it suitable for practical use under harsh conditions associated with higher output of transmissions. Even during this process, there is no occurrence of abnormal wear such as bright part wear or adhesive wear, and excellent wear resistance is exhibited over a long period of time.

[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, 3... Keyway.

Claims (2)

[Claims] (1) Contains Zn: 20-40%, Al: 2-8%, one or two of Ti and Zr: 0.1-3%, Sn: 0.1-3%, and the rest is made of a Cu-based alloy having a composition (by weight %) consisting of Cu and unavoidable impurities, and an oxide film layer of 0.1 to 10 μm mainly made of aluminum oxide is applied to the required locations on the contact surface with the mating member. Synchronous ring for transmission made of Cu-based alloy formed with average layer thickness. (2) Contains Zn: 20-40%, Al: 2-8%, one or two of Ti and Zr: 0.1-3%, Sn: 0.1-3%, and further , Mn: 0.1 to 5%, and the rest is Cu and unavoidable impurities. A synchronizing ring for a transmission made of a Cu-based alloy, which is formed by forming an oxide film layer mainly made of aluminum with an average layer thickness of 0.1 to 10 μm.