JPH024745Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a rolling machine that forms a pinion, particularly a helical gear, on the outer peripheral surface of a workpiece.

<Prior art> A pair of rolling dies are moved relative to the workpiece held by the spindle center and the tailstock center in a direction orthogonal to the axial direction of the workpiece, and are rolled onto the outer peripheral surface of the workpiece. In conventionally known rolling machines that form helical gears, especially when rolling helical gears with an odd number of teeth, the tip of the tooth of the rolling die meshes with the bottom of the tooth of the workpiece in the axial direction due to the odd number of teeth. The position of the rolling die is different between the left and right rolling dies, and the meshing point is shifted by half a pitch, which causes a bending moment in the horizontal plane near both ends of the face width, causing the workpiece to swing left and right, and further causing the downward movement of one of the rolling dies. The moment and the upward moment of the other rolling die cause the workpiece to swing up and down. As a result, the workpiece performs a grinding motion, and the rolling pressure on the tooth surface between the workpiece and the rolling die changes, causing tooth trace waviness.

In particular, such grinding motion varies greatly depending on the rigidity of the tailstock center, and when the tailstock center has to be narrowed to support the inner hole end of the workpiece, as shown in Figure 2. becomes more pronounced.

<Purpose of the invention> The purpose of the invention is to minimize the above-mentioned grinding motion and reduce the waviness of the tooth surface.

<Structure of the invention> In order to achieve the above-mentioned purpose, the present invention has a small gap necessary for attaching and detaching the workpiece at the tip of the rotating shaft to which the tailstock center is attached, and the outer periphery of one end of the workpiece. This is provided with opposing restraining members.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, numeral 3 indicates a pair of left and right columns fixedly installed on the base of a rolling machine, and vertical guide surfaces 15a and 15b are provided on each inner surface of these columns 3. Tool support stands 16a and 16b are guided on the vertical guide surfaces 15a and 15b so as to be movable up and down,
It is designed to be driven up and down in opposite directions by cylinders (not shown). Tool support stand 16a, 16
A rolling die 6 is connected to b via wedge bodies 17a and 17b.
a, 6b are fixed by clamp members 18a, 18b with their tooth surfaces facing each other. Engagement members 21a and 21b are provided on both sides of the rolling dies 6a and 6b to engage the workpiece W from both sides in the horizontal direction.
are provided along the rolling dies 6a, 6b, and the gap between these engaging members 21a, 21b is set to be slightly smaller than the diameter of the workpiece W to be held, with a slight penetration allowance into the workpiece W. It is adapted to engage with the outer periphery of the workpiece W, and prevents the workpiece W from vibrating in the horizontal direction during rolling.

4 is a main shaft, and this main shaft 4 is fixed to a frame 40 that is integrally provided between the left and right columns 3. The main shaft 4 has an axial center line in a horizontal direction perpendicular to the vertical movement direction of the rolling dies 6a, 6b, and is placed at a position passing between the opposing rolling dies 6a, 6b. A center ram 4a extends vertically through the axis of the main shaft 4, and a main shaft center 5 is fitted to the tip of the center ram 4a. A synchronous pinion 19 is fixed to the outer periphery of the tip of the main shaft 4, and a synchronous rack 20 is fixed to the tool supports 16a and 16b.
It meshes with a and 20b.

11 is a tailstock provided opposite to the spindle center 5 of the spindle 4, and as shown in FIG. 2, this tailstock 11 is movable forward and backward on a horizontal guide surface 9 provided on the base. It is designed to be guided forward and backward by a cylinder (not shown).

A ram 23 is fitted into the main body 12 of the tailstock 11 so as to be movable forward and backward, and a rotating shaft 24 is rotatably supported on the ram 23 on the same axis as the spindle center 5. A tailstock center 25 is fitted into the center of the tip of the rotating shaft 24, and the tip of the tailstock center 25 has a small diameter to support the end of the inner hole of the workpiece W. A ring-shaped restraining member 26 is fixed to the distal end surface of the rotating shaft 24, and the inner periphery of this restraining member 26 has a minimum clearance necessary for attaching and detaching the workpiece W to the outer periphery of the cylindrical part at one end of the workpiece W. These gaps are opposed to each other, and the behavior of the workpiece W that crosses this gap is restrained. The rotating shaft 24 is normally held at the forward end position where the stopper 27 collides with the main body 12 by the action of fluid pressure supplied to the rear end chamber, so as to absorb the axial elongation of the workpiece W due to rolling. There is.

In the figure, reference numeral 28 denotes a clamping device that presses the tailstock 11 against the base and restricts its retreat. A clamp shaft 31 is supported so as to be movable in a direction perpendicular to the direction in which the tailstock 11 moves forward and backward. An engaging member 34 that engages with an inclined surface 33 formed on the upper surface of the tailstock 11 is attached to the clamp member 32 fixed to the tip of the clamp shaft 31. In addition, 35 in the figure is a temporary holder for the workpiece W.
It is held by a tailstock 11.

In the above configuration, a pair of rolling dies 6
When the workpiece W is rolled by a and 6b, especially if the rigidity of the tailstock center 25 is weak, the workpiece W does not undergo a grinding motion, but the horizontal behavior of the workpiece W is caused by the engagement member. 21a and 21b, and the movement in the vertical direction is prevented by the restraint member 26, so that the waviness of the tooth surface of the workpiece W can be reduced.

In the embodiment described above, the restraining member 26 mainly prevents the vertical movement of the workpiece W, and the horizontal movement of the workpiece W is prevented by sandwiching the workpiece W from both sides in the horizontal direction. Although this is prevented by the engaging members 21a and 21b that fit together, it is also possible to restrict the grinding movement of the workpiece W only by the restraining member 26.

As described above, according to the present invention, the ring-shaped restraining members facing each other with a slight gap on the outer periphery of the cylindrical part at one end of the workpiece can prevent the workpiece generated when rolling a helical gear with an odd number of teeth. It has the effect of restraining the sawing motion and reducing the waviness of the tooth surface of the workpiece.

Moreover, according to the present invention, the support rigidity of the restraint member is increased by fixing the restraint member to the tip of a rotary shaft rotatably supported on a tailstock that is movably guided on a fixed base. This also provides the effect of reliably restraining the workpiece.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a cross-sectional view of a main part of a rolling machine, and FIG. 2 is a cross-sectional view taken along the - line in FIG. 1. 3...Column, 4...Spindle, 5...Spindle center,
6a, 6b...Rolling die, 11...Tailstock, 2
4... Rotating shaft, 25... Tailstock center, 26...
Restraint member, W...workpiece.

Claims (1)

[Scope of utility model registration request] A pair of rolling dies are moved relative to the workpiece held by the spindle center and the tailstock center in a direction perpendicular to the axial direction of the workpiece to form an odd number of teeth on the outer circumferential surface of the workpiece. In a rolling machine for forming a gear, a rotating shaft fitted with the tailstock center is rotatably supported on a tailstock that is guided on a fixed base so as to be movable forward and backward, and the tip of the rotating shaft is rotatably supported on a fixed base. A rolling machine characterized in that a ring-shaped restraining member is provided opposite to the outer periphery of a cylindrical portion at one end of the workpiece with a small gap necessary for attaching and detaching the workpiece.