JPH0746818Y2 - Dog gear of synchronizer for transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a dog gear of a synchronizing device for a transmission, which does not require finishing of a shift stopper surface when a main gear and a clutch gear are integrated.

(Prior Art) A main gear and a clutch gear, which constitute a conventional vehicle synchronizer for a transmission, are manufactured separately, and as shown in FIG.
After fitting the clutch gear 2 into the body 3 of the main gear 1,
Mating surface 6 between main gear body 3 and clutch gear body 4
Are fused and integrated. On this mating surface 6, there is a shift stopper 5 exposed between the main gear 1 and the clutch gear 2. The shift stopper 5 regulates the sliding movement of a coupling sleeve (not shown) that constitutes the synchronizing device. FIG. 4 is a view taken in the direction of arrow A in FIG. 3, and the shift stopper 4 is also exposed between the main gear 1 and the clutch gear 2 and between the teeth of the clutch gear 2.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional example, since the main gear 1 and the clutch gear 2 are separately manufactured and integrated by welding, the number of manufacturing processes increases and mass productivity is low. It was Therefore, it has been considered to reduce the working process by manufacturing a dog gear in which the main gear 1 and the clutch gear 2 are integrated by cold forging.

However, a new problem arises when manufacturing such a dog gear. That is, as shown in FIG. 5, when the dog gear 10 shown in FIG. 3 in which the main gear 1 and the clutch gear 2 are integrated is manufactured by cold forging, in order to obtain the effective tooth length of the clutch gear 2, the clutch The periphery 7 of the gear 2 needs to be recessed. For this reason, the shift stopper 5 is formed in a fragmentary manner only above the clutch gear 2 as shown in FIG. 6 (a view from the arrow B of FIG. 5).

Further, the boundary portion between the shift stopper 5 and the clutch gear 2 is a curved corner portion 9 as shown in FIG. 7 during cold forging, and if this corner portion 9 is left as it is,
This corner portion 9 hinders the shift operation of the coupling sleeve that constitutes the synchronizer, and there is a possibility that a malfunction such as a shift failure of the coupling sleeve or a gear loss may occur.
Therefore, this corner portion 9 is removed by cutting,
It is necessary to form the groove 8 as shown in the figure.

However, since the groove 8 is present intermittently together with the shift stopper 5, burrs are generated at the cutting start end and the end due to the cutting edge of the cutting tool (such as a drill) during cutting of the groove 8. Therefore, the finishing process is required, which causes an increase in the manufacturing process.

(Means for Solving the Problems) In order to solve the above problems, the present invention comprises a main gear and a clutch gear that are integrally formed, and has a clutch gear diameter smaller than the main gear diameter. In a dog gear in which a shift stopper is projectingly formed on a mating surface of a main gear body and a clutch gear body, the shift stopper has a part of the gear teeth of the clutch gear as a toothless portion, and the gearshift portion has the clutch gear It is characterized in that it is formed so as not to contact with.

(Operation) According to the present invention, the shift stopper has a part of the gear teeth of the clutch gear as a toothless portion and is formed so as to project in the toothless portion without contact with the clutch gear. The boundaries of can be discontinuous.

(Embodiment) An embodiment of a dog gear of the transmission synchronizing device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of a part of the dog gear 12, and the dog gear 12 of this embodiment includes a main gear 1 and a clutch gear 2.
Is integrated in its body and is manufactured by cold forging.

The shift stopper 25 in the dog gear 12 of this embodiment is
Part of the gear teeth of the clutch gear 2 (indicated by reference numeral 22 in the figure)
As a toothless portion, the toothless portion 23 is formed so as to project in the same plane as the virtual mating surface 16. Further, as shown in FIG. 1, the shift stopper 25 is formed in a substantially inverted trapezoidal shape at the toothless portion 23 and is formed in a non-contact state with the clutch gear 2.

The tooth-missing portions 23 are formed at a plurality of locations on the circumference of the clutch gear 2 at equal intervals. For example, it is desirable to maintain the synchro performance of the synchronizer and the strength of the clutch gear 2 by making the number of the toothless portions 23 the same as the number of insert keys or springs constituting the synchronizer. Further, in a double cone type synchronizer, it is desirable to provide three or more toothless portions 23 in consideration of the structure of the balk ring, the synchro cone, the key lock generating mechanism, or the like that constitutes the synchronizer.

With such a configuration, in the dog gear 12 of the present embodiment, it is not necessary to finish the shift stopper 25 after the cold forging, and the manufacturing process can be significantly reduced. This is because the continuous corner portion 9 as shown in FIG. 7 is not formed between the clutch gear 2 and the shift stopper 25, the cutting work of this portion is unnecessary, and the deburring work thereafter is also unnecessary. It is because

In addition, since the shift stopper 25 is formed on the virtual mating surface 16, a shift stroke failure of the coupling sleeve that constitutes the synchronizer does not occur, and a defect such as gear disengagement does not occur.

(Effects of the Invention) According to the present invention, the shift gear has a part of the gear teeth of the clutch gear as a toothless portion and is formed so as to project in the toothless portion in a non-contact manner with respect to the clutch gear. Compared with the conventional one in which a separate piece is welded, the number of manufacturing steps is greatly reduced and mass productivity is improved.

Further, when the dog gear is manufactured by cold forging, the boundary between the shift stopper and the clutch gear is discontinuous, so that the shift stopper does not need to be finished and the manufacturing time can be shortened.

[Brief description of drawings]

1 is a front view showing a part of a dog gear according to an embodiment of the present invention, FIG. 2 is a sectional view of the same part, FIG. 3 is a sectional view of a main gear and a clutch gear of a conventional synchronizer, and FIG. 3 is a sectional view of the dog gear when a dog gear in which a main gear and a clutch gear are integrally formed is temporarily manufactured, and FIG. 6 is a sectional view of the dog gear of FIG. 7
The figure is a cross-sectional view of the dog gear before finishing. 1 …… Main gear, 2 …… Clutch gear 12 …… Dog gear, 25 …… Shift stopper 16 …… Virtual mating surface, 23 …… Toothless portion

Claims (1)

[Scope of utility model registration request] 1. A dog gear constituting a transmission synchronizing device of a vehicle, wherein a main gear and a clutch gear are integrally formed, a clutch gear diameter is formed smaller than the main gear diameter, and a main gear. In a dog gear in which a shift stopper is formed to project on the mating surface of the body portion and the clutch gear body portion, the shift stopper has a part of the gear teeth of the clutch gear as a toothless part On the other hand, a dog gear of a transmission synchronizing device, which is formed so as to project in a non-contact manner.