JP3033990B2 - Synchronizer ring and transmission for transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a synchronizer ring for a transmission having excellent wear resistance and a transmission using the same.

[Prior Art] Generally, a synchronizer (synchronous meshing mechanism) ring of a synchromesh type transmission such as an automobile has a high surface with a tapered cone (not shown) whose inner surface 1 rotates, as illustrated in FIG. Intermittent surface contact occurs due to repeated synchronous sliding under pressure and repeated disengagement therefrom. A key groove 3 into which a synchronizer key is fitted is provided on the outer peripheral surface, and a chamfer 2 provided at a predetermined interval along an outer edge thereof is provided with a chamfer (not shown) of a hub sleeve as a mating member. Since it has a meshing function, it is required to have strength, resistance to demon king, and conformability with a mating member. Therefore,
Synchronizer rings include various Cu alloys having good characteristics such as sliding, synchronizing (playability with a mating member), and detachment, such as Cu-Zi, Cu-Al, Cu-Sn, and Cu-Ni. Series alloys have been used.

In addition, Ni sliding on the contact sliding surface with the taper cone of the sliding partner
A metal coating layer having a thickness of 1 to 100 μm made of a -P alloy has been proposed (JP-A-64-52079).

In addition, the synchronizer ring includes a so-called pin type in which a screw is provided on the outer peripheral side and the outer peripheral surface slides on the taper cone.

[Problems to be Solved by the Invention] In recent years, with an increase in output and speed of a transmission, improvement in wear resistance of a contact surface of a synchronizer ring with a taper cone, a chamfer, or a synchronizer key groove has been required. .

The conventional synchronizer ring is inadequate in this respect, and in particular, the challenge is to improve the wear resistance of the chamfer and the synchronizer keyway.

An object of the present invention is to provide a synchronizer ring for a transmission having excellent wear resistance such as a contact sliding surface, particularly a sliding surface with a taper cone, a chamfer, a synchronizer keyway, and a transmission using the same.

Another object of the present invention is to provide a synchronizer ring for a transmission having excellent wear resistance, excellent synchronism at the time of sliding contact with a taper cone, and excellent detachability therefrom, and a transmission using the same. .

[Means for Solving the Problems] The gist of the present invention for achieving the above object is as follows.

(1) At least the sliding surface of the synchronizer ring for the transmission that is in contact with the mating member is harder than the base metal, and
A first metal coating layer having a dynamic friction coefficient equal to or higher than that of the base metal is provided, and a second metal coating layer that is equal to or softer than the base metal is provided on the metal coating layer. Synchronizer ring for transmission.

(2) A synchronizer mesh having a sleeve connected to the slider, a synchronizer key cooperating with the sleeve, and a synchronizer ring pressed by the synchronizer key against a tapered cone portion of the gear to synchronize the gear and the synchronizer key by frictional force. In the transmission, a first metal coating layer, which is harder than a base metal of the synchronizer ring and has a dynamic friction coefficient equal to or higher than that of the base metal, is provided on at least a contact sliding surface of the synchronizer ring with the tapered cone. A transmission, wherein a second metal coating layer made of a metal equal to or softer than the base metal is provided on the metal coating layer.

In the present invention, the base metal of the synchronizer ring is preferably a Cu alloy, particularly preferably an alloy containing 2 to 15% by weight of Al. In addition, Zn is 20-40% by weight and Ni is 5% by weight.
Hereinafter, Si may contain 3% by weight or less, Mn and Fe may contain 5% by weight or less, and Ti may contain 2% by weight or less.

A feature of the present invention resides in that a metal coating layer which is harder than the base metal and has a dynamic friction coefficient equal to or higher than, for example, 0.1 or more is formed on the surface of the base metal. As the metal coating layer, there is, for example, a Ni-P coating layer. The coating layer can be formed by electroless plating,
The thickness is preferably from 0.1 to 100 μm on average.

If it is less than 0.1 μm, it is difficult to obtain desired wear resistance. Also, if it exceeds 100 μm, there is a risk of peeling,
No further effect is obtained, and the dimensional accuracy is deteriorated.

The hardness of the metal coating layer is 400 to 7 in Vickers hardness.
00 is preferred.

Further, on the first metal coating layer, a metal equal to or softer than the base metal, for example, Cu, Ni, Zn, P
one or more second metal coating layers selected from b, Sn and Al
It is particularly preferable to form it with a thickness of 0.1 to 50 μm.

Thereby, the synchronizing and detaching properties of the synchronizer ring can be improved, and the wear resistance can be improved. The second metal coating layer can be formed by electroplating.

In addition, since the hardness of the Ni-P alloy increases when it is subjected to the heat treatment, the heat treatment is often applied to those applied to ordinary metal parts and the like. However, it becomes brittle when heated, and in particular, when an impact force is applied, microcracks tend to occur and the wear resistance is impaired.

Therefore, in the synchronizer of the present invention,
It is better not to perform such heat treatment. However. If the heat treatment is performed at 250 ° C. or less, the effect is small.

[Action] The reason why the synchronizer ring for a transmission of the present invention has excellent wear resistance is that the metal coating layer provided on the surface layer has excellent wear resistance. By using the same metal alloy as the base metal as the metal coating layer, a material excellent in adhesion can be obtained.

In particular, since the Ni-P plating layer is hard, local partial contact is likely to occur, and cracks are likely to occur. But,
In the present invention, by covering the surface with a soft layer (second metal coating layer), there is an unexpected action and effect that the above-mentioned contact can be prevented and cracks can be prevented.

[Examples] The present invention will be described in detail with reference to examples.

Metal coating layers having the respective compositions shown in Table 1 were formed on the entire surface of a synchronizer ring having a minimum inner diameter of 70 mmφ and a thickness of 10 mm and an inner screw top land width of 0.09 to 0.1 mm.

Electroless Ni-P plating is Ni amount 4.9-5.1g /, pH about 4.5
The plating was performed at about 90 ° C. using the plating solution of The plating film is made of P
Consists of 11% by weight, with the balance being Ni.

By providing a soft Ni (pure Ni) layer by electroplating on the underlayer of the electroless Ni-P plating film, it acts as a buffer against an impact load and is effective in preventing cracks in the Ni-P plating film. I understood that. The thickness of the soft Ni plating film is preferably 2 μm or less.

Further, the second metal coating layer shown in Table 1 was formed on the first metal coating layer.
A synchronizer ring having a metal coating layer formed by a usual electroplating method was prepared.

In addition, a synchronizer ring having only an electrolytic copper plating film was formed as the metal coating layer.

Further, as a comparative example, a synchronizer ring in which only the second metal coating layer shown in Table 1 was formed by electroplating was also prepared.

Next, the various synchronizer rings were assembled in a transmission for an automobile, and a durability test was performed under the following conditions.

Shift position: 1st speed⇔2nd speed Shift operation force: 50 kgf Clutch plate rotation speed: 1200 rpm Lubricating oil (Temperature): Normal gear oil (60 ° C) Number of operations: 100,000 times After the endurance test, the chamfer shown in Fig. 4 Table 1 also shows the wear amount of No. 2, the wear amount (falling amount) of the sliding surface of the synchronizer ring with the taper cone, and the dynamic friction coefficient at the initial stage and after 100,000 times.

As is clear from the results shown in Table 1, the synchronizers of the present invention all have less chamfer abrasion than 1/2 of the comparative example, which is less than 1/2.

In particular, the one in which the second metal coating layer is formed has a large dynamic friction coefficient after running-in operation and is excellent in synchronism, and can achieve high output and high speed of the transmission.

Incidentally, those of Comparative Examples 7 and 8 did not withstand the durability test of 100,000 operations due to abnormal friction.

Next, FIG. 2 shows a change in Vickers hardness when the metal coating layer of the electroless Ni-P plating is heated at each temperature for one hour.

As is clear from the figure, the Vickers hardness gradually increases with an increase in the heating temperature. The Vickers hardness reaches about 1000 at 400 ° C., and gradually decreases when the temperature exceeds 400 ° C.

Normally, the wear resistance increases with an increase in hardness due to heat treatment. However, in the case of a synchronizer ring, an impact force is applied, so that microcracks tend to be formed on the metal surface, so that heat treatment is preferably not performed. However, heat treatment at 250 ° C. or lower may be performed.

Next, FIG. 3 shows a partial sectional view of a transmission using the synchronizer ring of the present invention.

When the sleeve 6 is pushed in the direction of the arrow with a shift lever (not shown), the slider 7 and the synchronizer key 8 move to push the synchronizer ring 4, and the cone of the synchronizer ring 4 comes into contact with the rotating cone of the cyclonizing cone 5. Then, the synchronizer key 8 and the sleeve 7 start to rotate due to the friction. When the sleeve 7 is further pressed, the connection with the synchronizer key 8 is disengaged, and the sleeve 7 and the synchronizer ring 4 come into contact with each other on the chamfered inclined surface at the end thereof and press against each other. Prevent further transition.

When the synchronization is over and everything turns at the same speed,
Both the friction force and the reaction force disappear, and the sleeve 7 meshes with the synchronizer ring 4 and then with the main drive gear 10,
The coupling between the gear and the clutch is completed.

When a synchronizer ring provided with a coating layer of the embodiment of Table 1 was used as a synchronizer ring of the low gear portion of the transmission having the above structure, the synchronizer ring had a higher speed and a higher load than those of the comparative example. I could drive for a long time without stalemate.

Of course, by applying the present invention to gears such as a main drive gear, a second gear, a third gear, and a clutch gear of a transmission, a transmission with a longer life can be obtained.

[Effects of the Invention] According to the present invention, it is possible to provide a synchronizer ring and a transmission for a transmission having excellent wear resistance, good synchronism and releasability, and long life.

[Brief description of the drawings]

FIG. 1 is a perspective view of a synchronizer ring for a transmission, and FIG.
FIG. 3 is a graph showing the relationship between the heat treatment temperature and the hardness of the electroless Ni—P plating coating layer, FIG. 3 is a partial sectional view of the transmission, FIG.
The figure is a partial view showing a wear amount measuring section of the chamfer. DESCRIPTION OF SYMBOLS 1 ... Contact sliding surface with a taper cone, 2 ... Chamfer, 3 ... Synchronizer key groove, 4 ... Synchronizer ring, 5 ... Synchronizing cone, 6 ... Slider, 7 ... Sleeve, 8 ... Synchronizer key,
9 ... Hub, 10 ... Main drive gear.

Claims (5)

(57) [Claims] A first metal coating layer, which is harder than a base metal and has a dynamic friction coefficient equal to or higher than that of the base metal, is provided on at least a contact sliding surface of the synchronizer ring for a transmission with a mating member; A synchronizer ring for a transmission, wherein a second metal coating layer that is equal to or softer than the base metal is provided on the metal coating layer. 2. The method according to claim 1, wherein the first metal coating layer is a Ni—P alloy layer, and the second metal coating layer is at least one coating layer selected from Cu, Ni, Zn, Pb, Sn and Al. Item 2. A synchronizer ring for a transmission according to item 1. 3. A synchronizer ring for a transmission, wherein a copper coating layer is provided on at least a sliding surface in contact with a mating member, and a single layer selected from Ni, Zn, Pb, Sn and Al is provided on the coating layer. A synchronizer ring for a transmission, comprising the above coating layer. 4. A synchronizer having a sleeve connected to a slider, a synchronizer key cooperating with the sleeve, and a synchronizer ring pressed against a tapered cone portion of the gear by the synchronizer key to synchronize the gear and the synchronizer key by frictional force. In the mesh type transmission, a first metal coating layer, which is harder than a base metal of the synchronizer ring and has a dynamic friction coefficient equal to or higher than that of the base metal, is provided on at least a contact sliding surface of the synchronizer ring with the tapered cone. A transmission, wherein a second metal coating layer of a metal equivalent to or softer than the base metal is provided on the metal coating layer. 5. A synchronizer having a sleeve connected to a slider, a synchronizer key cooperating with the sleeve, and a synchronizer link pressed against a tapered cone portion of the gear by the synchronizer key to synchronize the gear and the synchronizer key by frictional force. In the mesh type transmission, a copper coating layer is provided on at least a contact sliding surface of the synchronizer ring with the taper cone, and one layer selected from Ni, Zn, Pb, Sn and Al is provided on the coating layer. A transmission comprising the above coating layer.