JPS5930617A - Female thread cutting machine - Google Patents

Abstract

PURPOSE:To cut female thread of large diameter, or to modify a screw thread at high velocity, without using a tapping machine. CONSTITUTION:An eccentric cylinder 33 is rotatably put into a slidably rotating bush 32 which is screwed in a casing 11. The eccentricity of a main shaft 55, which is rotatably fitted to the eccentric cylinder 33 in the eccentric state, is made to be changeable, and an internal thread cutting tool 57 which is unitarily fitted to the main shaft 55 freely rotatable manner, is spirally revolved around the axis of a bush 32 which is rotating and sliding. In such a manner, a female thread, having an arbitarily large diameter, can be accurately cut at a specified pitch. In this case, driving and cutting, and feeding in and out of the cutter 57 is designed to be taken out of a spindle 13 and a drive shaft 16, but they can also be taken out from either one of these two mechanisms.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for machining large-diameter internal threads that are difficult to process, modifying threads, and the like.

Conventionally, most female threads are machined using thread cutting tools, regardless of the size of the hole diameter. When cutting female threads with this tag, relatively high thread precision can be achieved for small-diameter items, but for example, in machine tools for radial drilling machines, the target is 1c@ degree or effective diameter tolerance of large-diameter female threads. There was a risk that the accuracy would deviate. For this reason, when machining large-diameter female threads, special tools have been manufactured or skilled workers have to be particularly careful in carrying out the work.

From this point of view, it is an object of the present invention to provide a device that can process large-diameter female threads and correct threads with high precision without using a tap.

The configuration of the female thread processing device of the present invention that achieves this objective is as follows:
A cylindrical casing with a female thread carved on the inner circumferential wall, and a male threaded part fitted and supported by the casing and screwed into the female thread on the outer circumferential wall, and a drive source. a rotary sliding bush connected to the rotary sliding bush; and a worm gear that is eccentrically supported in a rotatable pressure-fit manner with respect to the rotary sliding bushing and meshes with a worm rotatably attached to the rotary sliding bushing. An eccentric cylinder formed on the outer peripheral wall, a main shaft that is rotatably fitted and supported eccentrically to the eccentric cylinder and connected to a drive source, and a female thread machining tool attached to the tip of the main shaft. It consists of

Hereinafter, one embodiment of the female thread machining apparatus according to the present invention will be described in detail from k with reference to FIGS. 1 to 3. As shown in FIG. 1 showing the cross-sectional structure of this embodiment, a mechanical spindle 13 is rotatably supported by a mechanical head 12 to which a cylindrical casing 11 is integrally fixed. Shaft 14t - formed connection attachment 1
-15 is integrally fitted, and the feed drive shaft 16, which is rotatably supported by the machine head 12 parallel to the machine spindle 13, has an intermediate shaft rotatably attached to the casing 11. A feed shear attachment (20) having a feed drive gear 19' that meshes with the intermediate gear 18 of No. 17 is integrally fitted and rotatably supported by the feed attachment 20#'i casing 11.

The gear barrel 22 is provided with a feed rotary gear 21 that meshes with the feed drive gear 19 through the intermediate gear 18'f, and is spline-fitted with the spline shaft 14, and a rotation drive gear 23 is entirely formed on the outer peripheral surface. A spline cylinder 24 is rotatably supported, and a cylindrical gear box 25 is integrally connected to the outside thereof. This gear box 25 and casing 11
A screw key 28 is integrally formed on the inner circumferential surface of the threaded bushing 26 that is slidably fitted between the Further, an internally threaded metal fitting 3o, which is integrally fixed to the casing 11, is screwed into a male threaded portion 29 formed on the outer peripheral surface of the threaded bushing 26. Therefore, during the rotation of the feed drive shaft load 6, the threaded bushing 2G is rotated °-sing 1.
1 in a spiral manner. This screw bush 2
A rotary sliding bush 32 that is slidably supported by the casing 11 via a bearing 7"31"i is integrally connected to the tip of the rotary sliding bush 32. Eccentric tube 3 that is eccentric by a certain amount with respect to the rotating sliding bush 32
3 is rotatably supported. As shown in FIG. 2, which shows a cross section taken along the arrow ■-n in FIG. A worm shaft 36 equipped with a worm shaft 35 is rotatably supported through the entire worm box 37 fixed to the rotary sliding bush 32, so that by rotating the worm shaft 36, the eccentric tube 33 is rotated and slid. Rotates relative to bushing 32. An eccentric bearing bushing 38 that engages with the tip of the gear box 25 is slidably fitted into the base end of the eccentric cylinder 33, and the inner circumference of the eccentric cylinder 33 is fitted onto the outer circumferential surface of the eccentric bearing bushing 38. A keyway ``40'' is cut parallel to the machine spindle 13, which engages a cross key 39 fixed to the surface. The intermediate shaft 42, which is rotatably supported at both ends by the eccentric bearing bush 38 and a rotating gear box 41 integrally attached to the eccentric bearing bush 36, has a bearing integrally connected to the gear cylinder 22. Eccentric tube 33 with respect to box 43
an intermediate gear 46 that meshes with a gear 45 integrated with an eccentric gear shaft 44 coaxially and rotatably supported; and an eccentric bearing bush 384C that is rotatably supported with an eccentric bearing bushing 384C that is eccentric to the eccentric cylinder 33 by a certain amount. Formed gear 4
8 and an intermediate gear 49 that meshes with the intermediate gear 49 is provided. The other gear 501C formed on the eccentric gear shaft 44 is
4 other parts integral with the intermediate shaft 53, which have an intermediate gear 51 that meshes with the rotary drive gear 23 formed in the spline cylinder 24, and whose both ends are supported by the gear cylinder 22 and a bearing box 52 integral with the gear cylinder 22; The intermediate gears 54 mesh with each other to transmit rotational force to the eccentric gear shaft 44 and the spline cylinder 47, which are eccentric with respect to the spline shaft 14, respectively. A spline shaft 56 that fits into the spline cylinder 47 is formed at the base end of the main shaft 55, which is rotatably supported with a certain amount of eccentricity with respect to the eccentric cylinder 33, and a threaded cutter 57 is integrally attached to the distal end. A rod-shaped cutter arbor 58 is fixedly attached. Accordingly, the operation of the machine spindle 13 causes the thread cutting cutter 57 to rotate together with the main shaft 55.

As shown in FIG. 3, which shows the thread cutting operation state according to this embodiment, the machine head 12 is moved so that the axis 59 of the machine spindle 13 and the axis 62 of the screw pilot hole 61 formed in the workpiece 60 are in a straight line. and the worm 60, and then operate the worm shaft 36 to rotate the thread cutter 570 axis 64'fc around the axis 63 of the eccentric cylinder 33, and adjust the effective thread diameter of the pilot hole 61. The axis 62 of the screw pilot hole 61 corresponds to
Adjust the distance from to the farthest tip of the thread cutter 57. Then, when the mechanical spindle 13 is activated,
The rotational force is applied to the spline shaft 1 of the connection attachment 15.
4 to spline tube 24. Intermediate shaft 53. Eccentric gear shaft 44
゜Spline cylinder 47 via intermediate shaft 42. Spline shaft 56 of main shaft 55. Canter arbor 58. Thread cutter 5
7. On the other hand, the rotational force of the feed drive shaft 16 is transmitted from the feed actuator 20 to the intermediate shaft 17. Gear cylinder 22. Gear box 25. Subeki 26. It is transmitted to the rotating sliding bush 32 # eccentric cylinder 33 via the threaded bushing 26, but since the male threaded portion 29 of the threaded bushing 26 is engaged with the female threaded hardware 30Kq integrated with the casing 11, the rotational sliding Bush 32. The eccentric cylinder 33 slides back and forth with respect to the pressure casing 11 in parallel with the axis 59 of the machine spindle 13. In order for these rotary sliding bushing 32 and eccentric cylinder 33 to perform a helical turning movement that matches the lead of the male threaded portion 29 of the threaded bushing 26, the main shaft supported by the eccentric cylinder 33 is
and cutter arbor58. The thread cutting secanter 57 turns spirally around the axis 59 of the machine spindle 13, that is, the axis 62 of the screw pilot hole 61, and a female thread with a lead equal to the lead of the male threaded portion 29 of the threaded bushing 26 is attached to the workpiece 60. engraved. Therefore, the pitch accuracy etc. of the female thread formed on the workpiece 6o depends on the accuracy of the male threaded part 29 of the threaded bushing 26 and the female threaded hardware 30 that is screwed thereto, so these should be assembled so that there is no breakage 2. It is necessary to keep it. In this embodiment, the drive rotation and feed movement of the thread cutter 57 are performed by the machine spindle 13 and the feed drive shaft 16.
Although pressure is given to take it out from both sides, it is of course possible to take it out from either side.

As described above, according to the female thread processing device of the present invention, the eccentric cylinder is fitted into the rotary sliding bush that is screwed into the casing so as to be able to rotate fully, and the eccentric cylinder is attached to the eccentric cylinder so as to be rotatable in an eccentric state. Since we made it possible to change the amount of eccentricity of the main shaft,
The tool for machining female threads, which is integrated with the main shaft, revolves around the axis of the rotating sliding bush in a spiral shape while being driven and rotates, and can accurately carve female threads of any large diameter with a predetermined pinch. It has become possible.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the internal structure of an embodiment of the female thread processing device according to the present invention, Fig. 2 is a sectional view taken along the arrow n-1, and Fig. 3 is a conceptual diagram showing the thread cutting operation state. Ash,
In the figure, 11 is the casing, 12 is the mechanical head, 13 is the machine spindle, 15 is the connection attachment, 16 is the feed drive shaft, 17, 42, 53 is the intermediate shaft, 20 is the feed attachment, 22 is the gear barrel, 24.47/fi spline cylinder, 25 company gear box, 26 threaded bushing, 27, keyway, 28 is sliding key, 29 is male threaded part, 30 female threaded hardware, 32Fi rotating sliding bushing, 33i1tlliA No1. ? 1. Symbol 1134 is a worm gear, 35 is a worm, 37 is a worm box, 44 is an eccentric gear shaft, 55 is a main shaft, 57 is a thread cutting blade, 58 is a canter arbor, 60 is a workpiece, and 61 is a screw hole. Patent applicant Mitsubishi Heavy Industries, Ltd. Sub-agent Patent attorney Shibe Mitsuishi (1 other person)

Claims (1)

[Claims] A cylindrical metal casing with a female thread carved on the inner peripheral wall, and a male thread that is fitted and supported by the casing and screwed into the female thread, carved on the outer peripheral wall and connected to a drive source. A worm gear is formed on the outer peripheral wall of the rotary sliding bush, which is rotatably fitted and supported eccentrically to the rotary sliding bushing, and meshes with a worm rotatably attached to the rotary sliding bushing. It consists of an eccentric cylinder, a main shaft that is rotatably fitted and supported eccentrically to the eccentric cylinder and connected to a drive source, and a female thread machining tool that is attached to the tip of the main shaft. Female thread processing equipment.