JPS6127117A - Planetary ball die - Google Patents

Abstract

PURPOSE:To provide the titled die enabling the adjustment of the rate of reduction in area without worsening the surface condition after working by tapering the inner peripheral face of an outer race. CONSTITUTION:A ball 5 is moved in the direction of the center shaft of a die in case of making an area reduction rate bigger and is moved in the reverse direction for making the reduction rate smaller since the ball 5 is moved in radial direction by the taper of the inner peripheral face of an outer race 2. In this case it is preferable to adjust the position of the ball 5 by changing the thickness of a spacer 8 or pressure backing plate 4 to receive the force in axial direction so that the force which the ball 5 is pressed to the axial direction of the die is not received with the tapered surface. The method controlling the position in the die direction of a thrust bearing 6 by an oil pressure is preferable especially in case of changing the reduction rate during the work.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a die used for drawing and indentation.

(b) Prior art and problems Generally, cross-section reduction processing is performed by drawing or pushing using a rigid die. In this case, the die surface and the surface of the workpiece are in close contact with each other, so the frictional force during processing is large, and the reduction of the cross section is done all at once over the entire circumference of the rod or tube, so a large pulling force or pushing force is required. is necessary. If this force becomes too large, the workpiece will break or buckle. In order to solve this problem, we developed a J rotating die (for example, Takeyasu Inoue et al. ``Thin-walled hollow tube using a rotating die'') from the viewpoint of reducing the axial force by having the machining work also be supported by torque. "Drawing Process", Plasticity and Processing, Vol. 7
Volume otoko issue PI'/! ;-P/;2/) and planetary ball dies (e.g. Kozo Kanayama et al. Patent Application No. 7)
-070ri! 7) was devised. However, rotary dies leave grooves on the surface after machining, while planetary ball dies leave almost no grooves, but have the disadvantage that the cross-sectional reduction ratio cannot be adjusted.

(Q) Purpose of the Invention The purpose of the present invention is to improve a planetary ball die so that the cross-sectional reduction ratio can be adjusted without deteriorating the surface quality after processing.

(d) Means for solving the problem In order to adjust the cross-sectional reduction ratio, it is sufficient to adopt a structure in which the position of the die in the radial direction of the ball (5) can be adjusted.

That is, this is made possible by tapering the inner peripheral surface of the outer race (2). For example, in order to increase the cross-sectional reduction ratio, the ball (5) may be moved to the right side. That is, due to the taper of the inner circumferential surface of the outer race (2), the ball (5) moves in the die radial direction and approaches the center axis of the die. On the other hand, the ball (5
) can be moved to the left to reduce the cross-sectional reduction ratio.

Here, in order to avoid deteriorating the surface quality of the workpiece,
This tapered surface must be designed so that the receiver does not receive the force that pushes the ball in the direction of the die axis. (Patent application number,
! ;7-070927> Therefore, in order for the receiver to have this axial force, by changing the thickness of the spacer (3) or the pressure receiving plate (4), the ball (5) and the pressure receiving plate (
4) It is important to maintain contact. Note that it is also possible to control the position 6 of the thrust bearing (6) in the direction of the die axis using hydraulic pressure.

(e) Operation of the Invention The cross section is reduced by rotating the planetary ball die and passing the rod or pipe material through it. That is, as the ball rolls around the workpiece, local machining is accumulated. The cross-sectional reduction ratio is baud/L
/ Since it is determined by the contact position between (5) and the inner circumferential surface of the outer race (2), the cross-sectional reduction ratio is reduced by moving left and right in the direction of the Radice axis. be able to. This can be adjusted by changing the total thickness of the spacer (8) or the pressure plate (4). The position of the ball (5) can also be adjusted by controlling the position of the thrust bearing (6) in the die axis direction using hydraulic pressure.

In this way, by tapering the inner peripheral surface of the outer race (2), the cross-sectional reduction ratio can be adjusted.
) If the contact position with the inner peripheral surface changes, there is a risk that grooves will remain on the surface after processing. In order to prevent this, the thrust bearing (6) can absorb the force that pushes the ball (5) in the direction of the die axis. If outer lace (2
) When the force is applied to the inner surface of the ball, the ball is pushed to the right, and the spacer (8) and pressure receiving plate (4)
(If the ball (5) is thin and the ball (5) does not contact the pressure plate (4) on the right side), the ball (5) moves left and right due to variations in the deformation resistance of the workpiece, and accordingly, the ball (5) moves in the radial direction of the die. It also fluctuates (in the vertical direction in the figure). To prevent this, the spacer (3) and the pressure receiving plate (4) should be placed so that the bow/l/(5) and the left and right pressure receiving plates (4) are in contact with each other.
The thickness must be adjusted.

The positioning may be performed using hydraulic pressure instead of the spacer (8).

(f) Embodiment of the Invention Using a planetary ball die improved as shown in Fig. 1, a stainless steel pipe was subjected to tube shrinking processing, and the groove height on the surface after processing was measured as shown in Fig. 3. The results were obtained. The data in Figure 3 is for an outer diameter of 2 Ω and a wall thickness of 2 for 5.
This is a case of processing TJS3011 pipe. The taper angle of the inner peripheral surface of the outer race (2) was 70°, and the tube shrinkage ratio was changed by changing the thickness of the left and right spacers (8).

The data is shown when the thickness is 70g on both the left and right (pipe shrinkage rate 79%) and when the thickness on the left is 7 and the thickness on the right is 720g (pipe shrinkage rate 10%).

(g) Effects of the Invention As explained above, the present invention improves the surface texture after processing in a planetary ball die that reduces the axial force during cross-section reduction processing to reduce the risk of material breakage and buckling. This makes it possible to easily change the reduction ratio of the cross section without causing deterioration.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the improved planetary ball die, Figure 2 is a schematic diagram of making a stepped round bar by changing the cross-sectional reduction ratio during processing, and Figure 3 is a tube reduction using the improved planetary ball die. FIG. 3 is a diagram showing the relationship between the height of the groove remaining on the surface of the processed stainless steel pipe and the feed rate per die/rotation. /...Press plate, 2...Araku lace, 3...Press plate, Ri...Pressure plate, 5
...Ball, B...Thrust bearing, 7
...ball holder, spacer,
De...Ball, 10...Stepped round bar

Claims (1)

[Claims] 1. Variable cross-sectional reduction rate type planetary ball die 2 with a tapered inner peripheral surface of the outer race (2), changing the thickness of the spacer (8) or the pressure plate (4). The planetary ball die 3 according to claim 1, in which the position of the ball (5) is adjusted by hydraulic pressure, and the planetary ball die 3 according to claim 1, in which the position of the thrust bearing (6) is adjusted by hydraulic pressure ball dice