JPH08209267A - Synchronous ring for speed change gear made of cu-base alloy - Google Patents

Abstract

PURPOSE: To obtain a synchronous ring for a speed change gear made of a Cu-base alloy excellent in initial fitness by producing a synchronous ring constituted of a Cu-base alloy having a specified componental compsn. and in which a work hardened layer having specified average thickness is formed on the required place in the working face with the mating member. CONSTITUTION: A synchronous ring constituted of a Cu-base alloy having a compsn. contg., by weight, 20 to 40% Zn, 2 to 8% Al, 0.2 to 2% Si, 0.1 to 5% Mn, 0.05 to 0.5% Ti and/or Zr, and the balance Cu with inevitable impurities, and in which a work hardened layer having 10 to 300μm average layer thickness is formed on the required place in the working face with the mating material (such as taper cones, keys or the like) is formed is produced. Moreover, the worked layer is formed by working such as shot blasting, sand blasting or the like. Thus, the synchronous ring for a speed change gear in which the generation of abnormal wear in the initial stage of the use is suppressed is obtd., and excellent performance is shown over a long period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Cu-based alloy synchronizing ring for a transmission, which is particularly excellent in initial conformability of a contact surface with a mating member and exhibits excellent performance over a long period of time.

[0002]

2. Description of the Related Art Conventionally, a synchronizing ring for a transmission is generally
As illustrated in a perspective view in FIG. 1, the inner surface 1 serves as a contact surface with a rotating taper cone, and a taper cone as a mating member intermittently comes into surface contact with the contact surface under high surface pressure, while the outer surface has one surface. Is formed with a key groove 3 into which a key is fitted, and the chamfers 2 provided at predetermined intervals along the outer edge of the key groove 3 have a function of engaging with chamfers of a hub sleeve which is also a mating member. , And the compatibility with the mating member is required, and therefore, high strength brass having these characteristics is frequently used in the production thereof. In addition, there is another type of the synchronous ring having a so-called pin type in which a screw is provided on an outer peripheral side and friction occurs with a tapered cone as a mating member on the outer peripheral side.

[0003]

However, with the recent increase in the output of transmissions, in the above conventional high-strength brass synchronizing ring, in particular, the taper cone and the key, and the chamfer of the hub sleeve are used. Since the contact surface with at least one of the mating members receives high surface pressure,
The initial conformability is reduced, and as a result, abnormal wear due to brilliant surface wear and adhesion wear occurs frequently, which causes a shortened service life.

[0004]

Therefore, the present inventors have
As a result of conducting research to solve the above-mentioned problems of the conventional high-strength brass transmission synchronous ring, Zn: 20 to 40% by weight (hereinafter,% indicates weight%), A
l: 2 to 8%, Si: 0.2 to 2%, Mn: 0.
1 to 5%, Ti and / or Zr: 0.05 to 0.5
%, With the balance being Cu and an unavoidable impurity, and a Cu-based alloy having a composition of Cu and unavoidable impurities, and at least a required portion of the contact surface with the mating member, that is, a taper cone or a key, and at least the chamfer of the hub sleeve. An average layer thickness of 10 to 3 by shot blasting or pressing using a cold press on the contact surface with one of the mating members.
The synchronous ring for a transmission made of a Cu alloy having a work hardened layer of 00 μm shows excellent initial conformability even under conditions of use under a high surface pressure accompanying an increase in the output of the transmission. The research results show that the occurrence of wear can be suppressed.

The present invention has been made based on the results of the above research, and explains the reasons for limiting the component composition and the average thickness of the work hardened layer as described above. (A) Zn and Al These components are components that determine the base structure of the alloy, improve the wear resistance of the base, provide the necessary strength and toughness to the synchronous ring, and further increase the fatigue strength. Excellent in proof stress, indispensable for forming a work hardened layer on the ring surface that prevents adhesion (seizure) due to plastic flow due to local high-temperature heating, thereby preventing initial abnormal wear and improving initial conformability Component, the content of which is Zn: 20
% And Al: less than 2%, not only the above properties cannot be ensured, but also it becomes difficult to form a work-hardened layer having the above properties, while the content thereof is Zn: 40% and If the Al content exceeds 8%, the toughness tends to decrease, so the content is set to Zn: 20-4.
0%, desirably 25 to 35%, Al: 2 to 8%, desirably 3 to 6%.

(B) Si and Mn These components combine with each other to form an intermetallic compound that is finely dispersed in the base material, thereby improving the strength and toughness of the ring and further improving the wear resistance. It has the effect of improving the conformability and the seizure resistance of the processed effect layer, but the content is less than 0.2% of Si: and Mn:
If it is less than 0.1%, the desired effect cannot be obtained, while the contents are respectively 2% for Si and 5% for Mn.
If it exceeds 1.0, slag is often generated during melting, so the content is Si: 0.2 to 2%, preferably 0.
5 to 1.5%, Mn: 0.1 to 5%, preferably 1 to 4
Defined as%.

(C) Ti and Zr These components have the effect of improving the strength and toughness by finely spheroidizing a Mn-Si-based intermetallic compound dispersed in a base material, but having an effect of increasing the content by 0.1%. If the content is less than 0.05%, the desired remarkable effect cannot be obtained. On the other hand, if the content exceeds 0.5%, no further improvement effect is exhibited by the above-mentioned effect. ~ 0.5%,
It is preferably set to 0.07 to 0.3%.

(D) Work Hardened Layer The work hardened layer is shot blasted or sand blasted as described above, and when it is provided only on the friction surface with the tapered cone of the ring, for example, a steel die is used.
It can be formed by pressing with a cold press, etc., and the work-hardened layer formed in this way has excellent fatigue strength and proof stress in combination with its component composition. It exhibits excellent plastic flow resistance against high temperature heating, and as a result, it suppresses seizure and the like, thus preventing initial abnormal wear and exhibiting excellent initial conformability, but its average layer thickness is 10 μm. If the average layer thickness is less than 100 μm, the desired effect cannot be obtained. On the other hand, even if the average layer thickness exceeds 300 μm, the excellent effect cannot be ensured. Therefore, the average layer thickness is 10 to 300 μm, preferably 30 μm.
１００100%.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the synchronizing ring of the present invention will be specifically described with reference to embodiments. Using an ordinary high-frequency furnace, C having the component compositions shown in Tables 1 and 2, respectively.
Prepare a u-based alloy melt, mold casting, diameter: 200mm
A billet of φ × length: 400 mm is formed, and this billet is extruded into a round bar having a diameter of 60 mmφ by an extrusion press, and the round bar is cut into a predetermined length.
Hot forging is performed at a temperature within a range of 0 to 750 ° C., further cutting is performed, and subsequently, in the atmosphere, a diameter: 50 to 1
Shot blasting is performed using 2,000 μm SiC beads to form a work hardened layer having the average layer thickness shown in Table 1 over the entire surface.
mmφ × thickness: 4 mm, and number of chamfers:
Thirty-six inventive sync rings 1-11 and comparative sync rings 1-6 were manufactured, respectively. Note that the comparison synchronization ring 1
In Nos. 6 to 6, one of the conditions of the component composition and the average thickness of the work hardened layer (marked with * in Table 2) is out of the range of the present invention.

Next, with regard to the various synchronous rings obtained as a result, the rotation speed of the tapered cone as the mating member is 1000 rpm.
Pressing load: 65kg, Oil: No. 80 mission oil, Oil temperature: 75 ° C, Operation of taper cone: 20,000 times with 0.25-0.3 second synchronization time, perform synchro durability test,
The drop amount (wear amount) on the inner surface of the ring, the presence or absence of adhesive wear, the initial (up to 500 times) and the late (stable) friction coefficients are measured and observed, respectively. .pm
Pressing load: 120kg, Oil: No. 80 mission oil, Oil temperature: 70 ° C, Operation of taper cone: 5000 times with 0.25-0.3 second synchronization time Cracks and deformation were observed. The results are shown in Table 3.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

[Table 3]

[0014]

From the results shown in Tables 1 to 3, all of the synchronizing rings 1 to 11 of the present invention have high strength and high toughness, and they are familiar in the initial stage of practical use in spite of the high surface pressure condition. It exhibits excellent properties and does not cause abnormal wear and exhibits excellent performance over a long period of time. On the other hand, as can be seen in the comparative synchronizing rings 1 to 6, the present invention can be applied to any of the constituent requirements. It is clear that when the value is out of the range, at least one of the above properties becomes inferior. Needless to say, the same result can be obtained with a pin type synchronizing ring. As described above, the synchronous ring for a transmission made of a Cu-based alloy according to the present invention has high strength and high toughness, is particularly excellent in initial conformability, and can be used under severe conditions associated with high output of the transmission. In such a case, there is no occurrence of abnormal wear such as bright surface wear or adhesive wear, and excellent performance is exhibited over a long period of time.

[Brief description of drawings]

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

Claims (1)

[Claims] 1. By weight%, Zn: 20-40%, Al: 2-8%, Si: 0.2-2%, Mn: 0.1-5%, Ti and / or Zr: 0.05. .About.0.5%, with the balance being a Cu-based alloy having a composition of Cu and unavoidable impurities, and a work-hardened layer having an average thickness of 10 to 300 .mu.m at required points on the contact surface with the mating member. Cu-based alloy synchronizing ring for transmission, which is formed with a thick thickness.