JPH0318097Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a tapping device built into a press mold.

(Prior art) Conventionally, when tapping is performed in a press die, a separate drive source such as a motor is provided inside the press die.
Tapping is performed by rotating the tap using this drive source. Alternatively, as shown in FIG. 4, attach the nut holder 3 holding the nut of the ball screw (not shown) to which the driving sprocket 2 is fixed to the upper die holder 1 of the press mold, and then attach the nut holder 3 holding the nut of the ball screw (not shown) to the upper die holder 1 of the press mold, and
The ball screw shaft 5 is engaged with the nut.
is installed. On the other hand, a tap holder 8 holding a driven sprocket 7 for rotating the tap 6 is attached to the upper mold holder 1. The driving sprocket 2 and the driven sprocket 7 are connected by a chain 10 via a chain tension 9. When the upper die holder 1 attached to a press (not shown) moves up and down, the drive sprocket 2 rotates by a nut (not shown) and the shaft 5, and the chain 10
Generally, when the driven sprocket 7 rotates, the tap 6 also rotates to perform tapping on the workpiece.

(Problem that the invention aims to solve) However, performing tapping using another drive source such as a motor requires a drive source to rotate the tap inside the press die, and the press speed cannot be increased, so the The disadvantage was that the machining speed, which is the most important characteristic of machining, decreased. On the other hand, the device shown in Figure 4 does not require a separate drive source, but since the tap is rotated by a chain drive, chain tension is required to prevent the chain from coming off or breaking due to loosening of the chain. The tap and drive source are separated, requiring a lot of space. As a result, the press die becomes larger and the punching layout becomes longer, resulting in a poor yield of the plate material being processed. The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a tapping device for a press die that allows tapping to be performed efficiently in a small space.

[Structure of the invention] (Means for solving the problem) The present invention utilizes the fact that an upper mold holder having a stripper expands and contracts the distance between the upper mold holder and the stripper due to the vertical movement of the press. A rotary shaft that penetrates the stripper and is rotatably attached to the stripper, a female threaded portion fixed to the upper die holder that screws into the threaded portion provided on the outer periphery of the rotary shaft, and an elastic member built into the rotary shaft. This is a tapping device for a press type, which is comprised of a sleeve that is inscribed in a rotating shaft that is biased against the body and has a slidable tap.

(Function) In the present invention, when the upper die holder is lowered, the stripper comes into contact with the workpiece on the lower die holder, and when the upper die holder is further lowered, the distance between the upper die holder and the stripper is reduced. As a result, the rotary shaft attached to the stripper is rotated by the female thread of the upper die holder that is screwed into the stripper, and the sleeve at the tip of the rotary shaft and inscribed therein is rotated by the elastic body. When the sleeve is biased, the tap attached to the tip of the sleeve performs the tapping process on the workpiece.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS. 1 to 3. A through hole 12 is provided in the center of the ball screw 11, and one end of the through hole 12 is an oval hole 13, and the other end is an internal thread 14. An oval-shaped sleeve 15 is fitted into the oval hole 13 so as to be slidable in the axial direction of the ball screw 11 but prevented from rotating in the radial direction. This sleeve 1
A tap 16 is fixed to 5. On the other hand, a set screw 17 is incorporated into the female screw 14, and a compressed coil spring 18 is inserted between the set screw 17 and the sleeve 15. A stepped portion is provided on the outer mold portion of the ball screw 11 on the oval hole 13 side, and a thrust bearing 19 and a radial bearing 20 are mounted on the stepped portion. This radial bearing 20 is press-fitted into the upper mold stripper 21, and the upper mold stripper 21 is held between the shaft nut 22 and the ball screw 11 by the thrust bearings 19 fitted above and below the upper mold stripper 21. In this way, the ball screw 11 is rotated while the upper stripper 21
is held in A plate 23 is attached to the lower part of the upper stripper 21 to prevent the sleeve 15 from falling.

On the other hand, a nut 24 screwed into the ball screw 11 is fixed to an upper mold holder 25. Upper mold holder 25
and the upper mold stripper 21 are connected by a guide post (not shown), and the spacing between the two is expanded and contracted by a spring 26. A workpiece 29 having a prepared hole 28 for tapping is installed on the upper surface of the lower mold holder 27.

Now, when the upper die holder 25 rises (Fig. 1),
A workpiece 29 in which a pilot hole 28 for tapping has been formed in the previous process is fed into the upper surface of the lower mold holder 27. From this state, the upper mold holder 25 descends, and the tap 16 comes into contact with the workpiece 29. When the upper die holder 25 descends further, the tap 16 and the sleeve 15 slide into the through hole 12 of the ball screw 11 and are pushed in, so that the plate 23 becomes the workpiece. It comes into contact with the object 29 (FIG. 2).
At this time, the coil spring 18 is in a compressed state, presses the sleeve 15 downward, and applies a downward force to the tap 16. When the upper mold holder 25 further descends, only the upper mold holder 25 and the nut 24 fixed thereto are lowered, and the others come to a halt, so that the distance between the upper mold holder 25 and the upper mold stripper 21 is reduced. become. Therefore, a rotational force is generated between the nut 24 and the ball screw 11 screwed into the nut 24, and the ball screw 11 starts rotating. This rotation of the ball screw 11 is transmitted to the tap 16 via the sleeve 15, and the tap 16 rotates. Since the downward force of the coil spring 18 is applied to the tap 16 via the sleeve 15, the tap 16 rotates while being pressed against the workpiece 29, sinks into the lower hole 28 of the workpiece 29, and performs the tapping process. conduct. When the upper die holder 25 reaches the bottom dead center of the press, the tap 16 completely enters the workpiece 29 and completes the tapping process (FIG. 3). Next, when the upper mold holder 25 rises past the bottom dead center of the press, only the upper mold holder 25 and the nut 24 rise, and the distance between the upper mold holder 25 and the upper mold stripper 21 widens, so that the ball screw 11 generates a rotational force in the opposite direction to that when descending, and the ball screw 11 rotates in the opposite direction, so tap 1
6 is untwisted from the workpiece 29 and becomes the workpiece 2
9, the press passes through the state shown in FIG. 2 and reaches the top dead center of the press, resulting in the state shown in FIG. 1. By repeating this cycle, tapping can be performed every cycle of vertical movement of the press.

[Effects of the invention] This invention attaches the rotary shaft to the stripper in a rotatable state, fixes the female threaded part to the upper die holder, and uses the vertical movement of the press to move the female threaded part up and down while fixing it to the upper die holder. As a result, the rotating shaft that is screwed into this is rotated, and the tap built into the rotating shaft is rotated, and the tapping process is performed during one cycle of the vertical movement of the press, making the structure of the press die simple and compact. , allows for efficient tapping processing in a small space. On the other hand, since the punching layout is also shortened, there is no need to worry about feeding the workpiece, and the yield of workpiece plates can be improved.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the tapping device for press molds of the present invention. Figure 1 is a cross-sectional view showing the upper die holder being raised, and Figure 2 is the state in which the stripper is in contact with it. 3 is a sectional view showing a state in which the upper die holder has been lowered to the lowest end, and FIG. 4 is a sectional view showing a conventional device. 11... Ball screw (rotating shaft), 12... Through hole, 13... Oval hole, 15... Sleeve, 16...
... Tap, 18 ... Coil spring, 19 ... Thrust bearing, 20 ... Radial bearing, 21 ... Upper stripper, 24 ... Nut (female thread), 25 ...
...Upper mold holder, 26...Spring.

Claims (1)

[Scope of utility model registration request] It consists of an upper mold holder and a stripper held by a spring so that the distance between the upper mold holder and the upper mold holder can be expanded and contracted by the vertical movement of the press, and a rotary shaft that passes through the stripper and is rotatably attached and an internal threaded part fixed to the upper die holder which is screwed into the threaded part provided on the outer periphery of the rotating shaft, and a female threaded part that is inscribed in and sliding on the rotating shaft which is biased by an elastic body built into the rotating shaft. 1. A tapping device for a press die, comprising a sleeve having a movable tap.