JP2646268B2 - Drilling equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a boring device, and more particularly, to a tool holder comprising a tool holder connected to a front end of a spindle and a cartridge having a cutting edge chip fixed thereto, and a draw bar. The present invention relates to a tool-exchangeable boring device which is clamped or unclamped by a pressing means.

(Prior Art) Conventionally, as this kind of boring tool, a slope base is attached to a chamfer formed on the outer peripheral surface of a front end portion of a tool holder according to Japanese Utility Model Publication No. 62-25287, and a cartridge is returned to the slope base. When the tool is retracted after boring, the cartridge is slid down the slope by the return spring, and the position of the cutting edge tip fixed to this is set to the diameter. It is known to shift inward in the direction so that the return mark is not attached to the inner surface of the hole.

In addition, the applicant of the present application has previously filed Japanese Utility Model Application No. 62-201231,
A long longitudinal groove is formed in the front-rear direction on the outer peripheral surface of the front end of the tool holder, and a longitudinally long cartridge having a cutting edge chip fixed to the front end is inserted into the concave groove, and the cartridge is inserted at the rear end. A single-acting cylinder fixed to a tool holder and formed in said tool holder to advance an internal piston against a return spring by a fluid supplied from a spindle side when the tool is retracted after boring; A piston rod extending forward from the piston rod is slidably inserted into the tool holder to form a tapered portion with a large diameter toward the front at the front end of the piston rod, and the piston rod is retracted into the tool holder. In this configuration, there is provided a pressing member that is pressed by the tapered portion and slides radially outward to press the front end portion of the cartridge radially outward, thereby impairing the support rigidity of the cartridge. It proposed a burr tool which is adapted shifting when the position of the cutting insert radially inwardly to the tool retraction without.

Further, in the tool holder gripping device disclosed in Japanese Utility Model Publication No. 62-8987, a tapered shank tool holder having a pull stud shaft fixed at the rear and a tool mounted at the front is provided. There is shown a tool holding device for a tool holder that is provided with a cutting agent passage in the axial direction through a stud and configured to discharge a cutting agent from near a cutting edge of a tool through the cutting agent passage.

In Japanese Utility Model Laid-Open No. 57-37105, a shaft having a piston rod has an outer shell portion containing a cylinder surrounding the shaft, and the shaft has three positions of forward, middle and retreat. The device is shown.

(Problems to be Solved by the Invention) According to the proposal proposed by the present applicant, an oil hole for supplying cutting oil to the spindle shaft core in order to supply fluid from the spindle side to the tool holder when the tool is retracted after boring. However, there is a problem that the method cannot be applied to the NC device or the machining center provided with the above.

Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to apply the present invention to an NC device or a machining center and to achieve a return mark without impairing the rigidity of supporting a cartridge. Another object of the present invention is to provide a boring device for a tool holder in which the position of a cutting edge tip is shifted inward in the radial direction when the tool is retracted in order to prevent the occurrence of the cutting edge.

(Means for Solving the Problems) According to the present invention, in order to achieve the above object, the tool holder has a longitudinal groove formed in a front-rear direction on an outer peripheral surface of a front end portion of the tool holder, and the concave groove has a front end portion. A longitudinal cartridge in which the cutting edge tip is fixed is inserted in the longitudinal direction, the cartridge is fixed to the tool holder at the rear end thereof, and a taper cone is inserted through the tool holder coaxially with the tool holder so as to advance and retreat. Forming a mounting portion at the rear end of the tapered cone, forming a flange portion at the center of the tapered cone,
A tapered portion having a large diameter on the front side is formed at a front end portion of the tapered cone, and a pull stud is provided in a rear end portion of the tool holder so that the front end surface is fixed to a mounting portion of the tapered cone so as to be movable forward and backward. The tool holder is pressed by the taper portion by the retraction of the taper cone against the return spring interposed behind the flange portion of the taper cone when the pull stud is retracted during boring, and slides radially outward. A presser that moves and presses the front end of the cartridge radially outward, the pressing means unclamping the tool holder at the forward position and radially inwardly moving the cutting blade at the intermediate position. A pressing member is provided which is displaced and clamps the tool holder via the draw bar at the retracted position.

Further, the pressing means has three stepped portions where the piston rod in the cylinder is positioned at three positions of forward, middle and retreat, and an air supply circuit for unclamping the tool holder at the forward position of the piston lot. An air supply circuit for displacing the cutting blade radially inward at an intermediate position of the piston rod, and an air supply circuit for clamping the tool holder via the draw bar at a position where the piston rod is retracted. It is recommended to be characterized.

(Operation) With the configuration described above, in the tool holder, the taper cone is normally advanced by the biasing force of the return spring, and at this time, the pull stud contacts the rear end of the tool holder. Then, the presser through the tapered portion of the taper cone abuts on the front end of the cartridge, and can be applied to a boring NC device having a draw bar or a boring device such as a machining center.

Thus, at the time of machining, the cylinder is at the retracted position from the draw bar, the pull stud is retracted by a small stroke by engaging with the engaging portion of the draw bar of the boring device, and the taper cone is retracted against the return spring. At this time, the pressing element through the tapered portion of the tapered cone is extruded a minute distance, whereby the front end of the cartridge is pressed radially outward, the cartridge is bent, and the front end is pushed up radially outward. The cutting edge tip fixed to this is located at the processing position radially outward.

At the time of retraction of the tool after boring, the cylinder advances the draw bar by a small stroke to the intermediate stop position, the pull stud is returned to the stop position by the draw bar, the taper cone is advanced, and the presser follows the inclination of the taper portion. The cartridge can be slid radially inward, and its front end moves radially inward by the elastic restoring force of the cartridge.
The cutting edge tip is displaced to a relief position radially inward of the processing position to prevent a return mark from being attached to the inner surface of the processing hole.

At the time of tool attachment / detachment, the cylinder advances the draw bar to an advanced position, and the pull stud is disengaged from the draw bar so that the tool holder can be attached / detached.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of the tool holder for the boring device according to the present invention at the time of retreat, FIG. 2 is a cross-sectional view of the tool holder for the boring device shown in FIG. 3
The figure is an explanatory view using the boring device according to the present invention.

1 and 2, 1 is a spindle, 2 is a draw bar, 3 is a tool holder, 4 is a groove provided in the tool holder 3, 5 is a cartridge provided in the groove 4, 6
Is a cutting edge tip fixed to the cartridge 5, 7, 7 is a bolt, 8, 8 'is a large-diameter shaft hole provided concentrically with the tool holder 3, and 9 is provided concentrically with the tool holder 3. A small diameter shaft hole, 10 is a concave hole provided concentrically on the tool holder 3, 11 is a small diameter shaft hole provided concentrically on the tool holder 3, 12 is a tapered cone, 13 is a return spring, and 14 is the tool A hole orthogonal to the axis of the holder 3, 15 is a presser, and 16 is a pull stud.

The tool holder 3 includes a rear shank 3a connected to the front end of the spindle 1 and a front shaft 3b.
A longitudinal groove 4 is formed in the front-rear direction on the outer periphery of the front end of the shaft portion 3b, and a longitudinally-extending cartridge 5 having a cutting edge chip 4 fixed to the front end by brazing or the like is mounted in the groove 4. And the rear end of the cartridge 5 is attached to the shaft 3 with two bolts 7,7.
Fixed to b.

In the shaft portion 3b, a large-diameter shaft hole 8 concentric with a stepped shaft opening at the rear end surface, a small-diameter shaft hole 9 extending forward from the shaft hole 8, and a cross at right angles to the shaft hole 9. A hole 14 is formed at the front end of the concave groove 4. The shank portion 3a has a shaft hole 8 'having the same diameter as the shaft hole 8 and a small diameter shaft hole 11 extending rearward from the shaft hole 8'. ,
A concentric large-diameter concave hole 10 is formed in a stepped shaft that opens from the shaft hole 11 to the rear end face.

The tapered cone 12 has a male screw at the rear end,
12a, a flange portion 12b at the center thereof, and a tapered portion 12c having a large diameter at the front side at the front end thereof are appropriately formed, and are inserted through the shaft holes 11, 8 ', 8 and 9. It is provided to be able to move forward and backward.

The pressing element 15 is a pin-shaped element having an appropriate length of rigidity, and is interposed between the front end of the cartridge 5 and the tapered portion 12c and is slidably movable in the radial direction by the hole 14. It is.

In the pull stud 16, a female screw 16a meshing with the male screw 12a is formed in the front end shaft portion, the front end shaft portion 16b is provided to be able to advance and retreat in the concave hole 10, and a stepped flange portion 16c is formed in the center portion, and A hanger portion 16d in the shape of a cocoon is formed at the end.

In the tool holder 3, the taper cone is normally advanced by the biasing force of the return spring 13 interposed between the shaft holes 8, 8 'and the flange portion 12b. At this time, the pull stud 16 has the flange portion 16c. The pressing member 15 is in contact with the rear end of the shank portion 3a and stops, and the pressing element 15 via the tapered portion 12c is in contact with the front end of the cartridge 5.

In FIG. 3, 1 is the spindle, 2 is the draw bar, 3 is the tool holder, 16 is the pull stud, 21 is the holding cylinder that holds the ball 2a and is attached to the draw bar 2, 22 is the fixed cylinder, 23 is a flat washer, 24 is a return spring, 25
Is a piston rod, 26 is a cylinder, 27 and 28 are pistons provided in the piston rod 25, 29, 30, and 31 are air holes provided in the cylinder 26, and 32 is a cylinder.
An air vent hole provided in 26, 33 and 34 are air pumps, 35 and 36 are check valves, and 37 and 38 are solenoid valves.

Thus, when the tool holder 3 is mounted, the air pump 34
Air is supplied from the air supply holes 30 and 31 by the operation of the solenoid valves 37 and 38, and the piston rod 25 has a stepped portion 25a
6 is the forward position in contact with the front end face. At this time, since the piston rod 25 presses the trolley bar 2 and the ball 2a is moving forward, the pull stud 6 is not engaged with the ball 2a. Therefore, in this state, the tool holder 3 can be mounted on the spindle 1.

Thus, at the time of machining, the tool holder 3 is mounted on the spindle 1 such as a machining center by the shank portion 3a, the air supply from the air pump 34 is stopped, and the air supply from the air pump 33 is supplied from the air supply hole 29. Then, the piston rod 25 is set to the retracted position where the stepped portion 25b contacts the rear end surface in the cylinder 26. At this time, since the piston rod 25 retreats from the draw bar 2, the draw bar 2 retreats the ball 2a together with the holding cylinder 21 by the urging force of the return spring 24. Accordingly, in this state, since the ball 2a is retracted, the hanger portion 16d is engaged with the ball 2a and is pulled and retracted, so that the tool holder 3 is completely clamped to the spindle 1.

Next, at this time, when the draw bar 2 retreats by a small stroke, the pull stud 16 is pulled back by the hanger portion 16d engaged with the ball 2a, and at the same time, the taper cone 1
2 is retracted against the urging force of the return spring 13, and at this time, the pressing element 15 is pushed out a minute distance via the tapered portion 12c, whereby the front end of the cartridge 5 is pressed radially outward, 5 is bent and the front end is pushed up in the radially outward direction, so that the cutting edge chip 6 fixed thereto is located at the processing position radially outwardly.

When the tool holder 3 is retreated after the boring, the air supply from the air pump 34 is supplied from the air supply hole 30 and the piston 28
At the same time, the stepped portion 25c of the piston rod 25 is moved to the intermediate stepped portion in the cylinder 26 and is set to the intermediate stop position. At this time, since the piston 25 advances the draw bar 2 by a small stroke, the ball 2a moves forward, the pull stud 16 becomes the above-mentioned stationary position, and the tool holder 3 can be maintained in the state held by the spindle 1.

When the tool holder 3 is retracted, the pull stud 16 is returned to the stop position by the draw bar 2, and the tapered cone 12
Is moved forward, and the presser 15 can be slid inward in the radial direction according to the inclination of the tapered portion 12c. The front end of the presser 15 moves inward in the radial direction by the elastic restoring force of the cartridge 5, and the cutting tip 6 The return mark is prevented from being displaced to the relief position radially inward of the processing position and being formed on the inner surface of the processing hole.

At the time of removing the tool holder 3, the draw bar 2 is advanced as in the case of the mounting, the hanger portion 16d is disengaged from the ball 2a, and the tool holder 3 is removed from the spindle 1 by a manipulator (not shown). Collected in the tool storage tool by the manipulator.

Thus, when the drilling tool according to the present invention is applied to an NC device or a machining device, a return mark is not generated on the inner surface of a drilled hole when the tool is retracted after drilling.

(Effect of the Invention) Since the present invention is configured as described above, according to the present invention, it can be applied to an NC device or a machining center. It is possible to provide a boring device for a tool holder in which the position of the cutting edge tip is shifted radially inward when the tool is retracted for prevention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the tool holder for the boring device according to the present invention when the tool holder is retracted. FIG. 2 is a cross-sectional view of the tool holder for the boring device shown in FIG. FIG. 3 is an explanatory view using the boring device according to the present invention. DESCRIPTION OF SYMBOLS 1 ... Spindle 2 ... Drawbar 3 ... Tool holder 4 ... Recessed groove 5 ... Cartridge 6 ... Cutting edge chip 12 ... Taper cone, 12a ... Male thread 12b ... Flange, 12c ... Taper Part 13 Return spring, 15 Presser 16 Pull stud 2a Ball, 21 Holding cylinder 24 Return spring 25 Piston rod 25a, 25b, 25c Stepped part 26 … Cylinder, 27, 28… Piston 29, 30, 31… Air vent 33, 34… Air pump 35, 36… Check valve 37, 38… Solenoid valve

Claims (2)

(57) [Claims] 1. A tool exchangeable tool comprising a tool mounted on a front portion and a tool for clamping or unclamping the tool holder by means for pressing a draw bar against a tapered shank tool holder having a pull stud at a rear portion. In the drilling apparatus, the tool holder has a longitudinal groove formed in the front-rear direction on an outer peripheral surface of a front end of the tool holder, and a longitudinal cartridge having a cutting edge chip fixed to the front end in the groove is inserted. Then, the cartridge is fixed to a tool holder at a rear end thereof, and a taper cone is provided in the tool holder so as to be able to advance and retreat coaxially with the tool holder, and a mounting portion is provided at a rear end of the taper cone. Forming a flange at the center of the taper cone, forming a large-diameter taper at the front end at the front end of the taper cone, and a rear end of the tool holder. A pull stud is fixed to the mounting portion of the tapered cone with its front end face provided so as to be able to advance and retreat, and the tool holder is interposed behind the flange portion of the taper cone by retreating the pull stud during boring. The taper cone is retracted against the return spring, and is pressed by the tapered portion to slide radially outward to press the front end of the cartridge radially outward. Means for unclamping the tool holder at the forward position, displacing the cutting blade radially inward at the intermediate position, and clamping the tool holder via the draw bar at the retracted position, comprising a pressing member. Drilling equipment. 2. The pressing means has three stepped portions in which a piston rod in a cylinder is positioned at three positions of forward, middle and retreat, and unclamps the tool holder at the forward position of the piston lot. An air supply circuit, an air supply circuit that displaces the cutting blade radially inward at an intermediate position of the piston rod, and an air supply circuit that clamps the tool holder via the drawbar at a position where the piston rod is retracted. The boring device according to claim 1, further comprising: