JP3118579U - Tool holding chuck and tool mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chuck that is attached to a spindle of a machine tool and grips a tool and has a short overall length and high rigidity, and is relatively light and easy to handle.
A frustoconical taper shank portion 3 that fits into a hole of a spindle 2, a fitting hole 7 is provided in the taper shank portion 3, and an insertion hole 8 is passed through the upper end portion to the upper end. 7 is fitted with the fitting part 12 of the chuck cylinder 4 with the disc spring 17 set at the upper end, and the chuck part 13 provided on the lower side of the chuck cylinder 4 extends downward from the lower end of the taper shank part and its outer diameter is The lower end side is narrowed, and a screw part 14 is formed on the outer periphery of the chuck part, and a tightening nut 5 is screwed together. It is screwed and suspended, and the shank 16 of the tool 1 is fitted into the hole of the chuck portion 13 and fixed with the tightening nut 5.
[Selection] Figure 1

Description

  The present invention relates to a chuck for gripping a cutting tool such as a drill and a chuck structure of the tool, and particularly to a chuck that is excellent in rigidity and capable of heavy cutting and is easy to handle.

  The chuck is a device for firmly holding the cutting tool on the spindle of the machine tool, and the cutting tool can be rotated together with the spindle via the chuck. The chuck is required to have a rigidity so that the cutting tool can be gripped accurately and the tool can be stably rotated without cutting during the cutting process. Therefore, the chuck generally has a large weight and is difficult to mount on the spindle of the machine tool.

  FIG. 3 shows a conventional chuck structure. The chuck of the cutting tool (b) has a holder body (b), and the holder body (b) is a tapered shank portion (d) inserted into a tapered hole provided in the spindle (c) of the machine tool, It has a gripping flange (e) formed at the lower end of the taper shank (d), and extends below the flange (e) in line with the axis of the taper shank (d). A chuck cylinder (f) is provided. Here, the outer peripheral surface of the chuck cylinder (f) is a tapered surface whose diameter decreases toward the lower tip.

  A roller holding ring (g) is loosely fitted on the outer periphery of the chuck cylinder (f), and this roller holding ring (g) faces the tip at a taper angle substantially similar to the taper surface of the chuck cylinder (f). It is formed from a cylinder having a small diameter. The roller retaining ring (g) is held so as not to fall out of the chuck cylinder (f) by a retaining ring provided on the outer periphery of the tip of the chuck cylinder (f).

  The roller holding ring (g) has a large number of needle rollers (h), (h),... Fitted at a predetermined angle in the circumferential direction with respect to the axis of the roller holding ring (g). It is arranged in several stages over the entire surface. Each needle roller (h), (h) is formed with a diameter larger than the wall thickness of the roller retaining ring (g), and thereby protrudes toward the inner peripheral surface side of the roller retaining ring (g). Each needle roller (H), (H), ... that protrudes to the outer peripheral surface side of the roller retaining ring (G) by contacting the rollers (H), (H), ... to the taper outer surface of the chuck cylinder (F) Is in contact with the inner peripheral surface of the tightening nut (re).

  The clamping nut (re) is a needle roller that reduces the diameter of the chuck cylinder (f) and tightly grips the target tool, and is held by a roller retaining ring (g) on the outer periphery of the chuck cylinder (f). It is fitted via (h), (h). The inner peripheral surface of the tightening nut (re) is configured as a tapered cylindrical surface whose diameter decreases from the end facing the flange (e) toward the tip. In addition, a retaining ring that also serves as a seal is attached to the inner circumference of the base end of the tightening nut (re) on the flange side, and this retaining ring that serves as a seal must abut against the outer peripheral surface of the chuck cylinder (f). The seal function is exerted by this, and by coming into contact with the end face of the roller retaining ring (g), it is prevented from coming off from the chuck of the tightening nut (re).

  In the conventional chuck configured as described above, when the tool (A) is gripped, the spring collet (L) is fitted to the shank (N) of the tool (I) and the tool ( Insert the shank (b) of b) into the cylindrical hole of the chuck cylinder (f). If the tightening nut (re) is rotated clockwise in this state, each needle roller (h) that contacts the tapered cylindrical surface of the tightening nut (re) is slightly inclined. In addition, the roller retaining ring (g) rotates from the lower side of the chuck cylinder (f) to the flange (e) because the outer peripheral surface of the chuck cylinder (f) revolves spirally while rotating in a direction perpendicular to its own axis. As the needle rollers (H), (H),... Revolve, they move while rotating, and at the same time, the tightening nut (R) also moves upward in the direction of the flange (E).

  As a result, the gap between the tapered cylindrical surface of the tightening nut (re) and the outer peripheral tapered surface of the chuck tube (f) is reduced, so that the tightening nut (re) is connected to each needle roller (h), (h) ... The chuck cylinder (f) is pressed from the outer periphery to reduce the diameter. As a result, the shank (nu) of the tool (a) inserted into the cylindrical hole of the chuck cylinder (f) is tightened and gripped via the spring collet (le). If the tightening nut is rotated counterclockwise, the roller retaining ring (g) moves downward toward the tip of the chuck cylinder (f) and the tightening nut (re) moves in the same direction. To do. For this reason, the chuck cylinder (f) whose diameter has been reduced is restored to its original diameter and the gripping force on the tool is released, so that the tool (b) can be removed or replaced.

  By the way, if the tightening nut (re) is rotated, it is moved upward to tighten the chuck cylinder (f) and the spring collet (le) to grip the shank (nu) of the tool (ii). In this case, a gap (e) is left between the upper end of the tightening nut (re) and the flange (e), and the presence of the gap (e) reduces the rigidity of the entire chuck. As a result, it is difficult to perform heavy cutting with the tool (a).

  Further, the conventional chuck structure has a flange (e) below the tapered shank (d), and further extends a chuck cylinder (f) downward from the flange (e). And, the spring collet (le) fitted with the shank (nu) of the tool (b) is fitted and held in the chuck cylinder (f), but the tapered shank part (d) is fitted. The distance from the spindle (c) of the machine tool is large. This also reduces the rigidity of the chuck and causes chattering during cutting.

On the other hand, a taper shank portion (d), a flange (e), a chuck cylinder (f), and a roller holding ring (g) provided with a needle roller (h) attached to the chuck cylinder (f) In addition, the chuck composed of the tightening nut (re) is heavier, and in a machining center equipped with a large number of tools (a), (a) ... Become. Furthermore, the manufacturing cost of the chuck is very high, and it is not easy to prepare for each tool.
“Chuck” according to JP-A-2005-103730

  As described above, the conventional tool gripping chuck has the above-described problems. The problems to be solved by the present invention are these problems, and provide a chuck for holding a tool and a chuck structure of a tool which are relatively light and easy to handle, have high rigidity and enable heavy cutting.

  The chuck for gripping a tool according to the present invention has a structure that can be attached to a spindle of a machine tool to grip a tool shank. The chuck for gripping a tool includes a taper shank, a chuck cylinder, and a tightening screw. It consists of nuts. The tapered shank has a frustoconical shape, has a straight fitting hole in the central shaft portion, and is fitted and attached to a hole in the spindle.

  An insertion hole is provided above the concentric hole of the taper shank. The pull stud connected to the spindle of the machine tool passes through the insertion hole, and the screw portion provided at the lower end of the pull stud is chucked. The chuck cylinder is suspended by screwing into a screw hole formed at the upper end of the cylinder central axis. In the present invention, the chuck cylinder is suspended by a pull-stat and at the same time the taper shank is held.

An elastic material is set at the upper end of the fitting part of the chuck cylinder that fits into the fitting hole of the taper shank. By lifting the chuck cylinder with a pull stud, the elastic material set at the upper end is compressed and deformed to taper. Chunks are fitted into the spindle holes.
The lower side of the chuck cylinder has a chuck portion extending downward from the lower end of the tapered shank, and the chuck portion is provided with a fitting hole in which a tool shank is fitted and attached.

  In addition, the outer peripheral surface of the chuck portion is provided with a screw portion having a slight taper with a thin tip and a plurality of slit grooves in the axial direction. By the way, a tightening nut is screwed onto the threaded portion on the outer periphery of the chuck portion, and the shank of the tool that fits into the fitting hole of the chuck portion is fixed by tightening the tightening nut. The upper end of the tightening nut is in contact with the lower end surface of the spindle without leaving a gap.

  The chuck of the present invention is a truncated cone-shaped taper shank that fits into a hole in a spindle, a chuck cylinder that is fitted and fitted in a center fitting hole of the taper shank, and a screw that is screwed into a chuck portion provided below the chuck cylinder Because it has a simple structure consisting of nuts and is compact, its weight is about 1/3 that of the conventional one, making it easy to handle and about half the production cost. Get cheaper.

  The lower part of the chuck cylinder fitted into the fitting hole of the taper shank extends downward, and since there is no conventional flange, the overall length of the chuck is shortened, and the chuck part provided on the lower side of the chuck cylinder The shank of the tool is fitted in the fitting hole, and the upper end surface of the tightening nut attached by screwing to the screw portion formed on the outer periphery of the chuck portion is attached in contact with the lower end surface of the spindle.

  Therefore, when the chuck is integrated with the spindle, its rigidity is increased and heavy cutting is possible, and chattering does not occur during cutting. Further, since the distance from the spindle to the lower end of the tool is shortened, the space between the workpiece (workpiece) and the tool is enlarged, so that the work becomes easy. On the other hand, the chuck of the present invention has a common taper shank that fits on the spindle, so there is no problem in attaching it to an existing machine tool.

  FIG. 1 is an embodiment showing a chuck for holding a tool and a chuck structure of a tool according to the present invention. In the figure, 1 is a tool, 2 is a spindle of a machine tool, 3 is a taper shank of a chuck, 4 is a chuck cylinder, 5 is a clamping nut, and 6 is a pull stud. The tapered shank 3 has a truncated cone shape with a thin upper portion, and is fitted in a hole provided in the spindle 2.

A fitting hole 7 is provided in the central shaft portion of the taper shank 3, and an insertion hole 8 having a smaller inner diameter is passed through the fitting hole 7 to the upper end. And the shaft part 9 formed in the lower end part of the pull stud 6 built in the spindle 2 is fitted into the insertion hole 8 of the taper shank part 3, and the screw part 10 extending downward from the lower end of the shaft part is the above-mentioned. The chuck cylinder 4 is suspended by being screwed into the upper end screw hole 11 of the chuck cylinder 4. The chuck cylinder 4 is suspended by fitting an upper fitting portion 12 in a fitting hole 7 provided concentrically with the central axis of the tapered shank 3, and the lower end portion extends downward from the tapered shank 3.
The chuck portion 13 of the chuck cylinder 4 extending downward from the lower end of the taper shank 3 is tapered so that the diameter of the outer peripheral surface thereof is slightly smaller on the lower side. Generally, a taper of about 2 ° is provided. Then, a screw portion 14 with a screw cut is formed on the outer peripheral surface, and the fastening nut 5 can be screwed into the screw portion 14 to fasten the chuck portion 13. Therefore, the chuck portion 13 has a cylindrical shape with a hole, and a plurality of slit grooves are formed in the axial direction, and the diameter is reduced by tightening the tightening nut 5.

  A spring collet 15 is fitted inside the chuck portion 13, and a shank 16 of the tool 1 is fitted inside the spring collet 15. Here, the spring collet 15 is formed with a plurality of slit grooves in the axial direction, and if a tightening force is applied from the outer periphery, the diameter can be reduced and the shank 16 can be gripped.

  Incidentally, the taper shank portion 3 fitted into the hole of the spindle 2 is held together with the chuck cylinder 4 suspended from the pull stud 6, and two disc springs 17 and 17 are placed on the upper end of the chuck cylinder 4. Has been. If the threaded hole 11 formed at the upper end of the chuck cylinder 4 is screwed into the threaded part 10 of the pull stud 6, the disc springs 17, 17 are compressed and deformed, and the tapered shank part 3 is combined. In this state, the pull stud 6 is attached to the lifting tool built in the spindle and is lifted up as shown in FIG.

  By the way, when the tool 1 is gripped, first, the clamping nut 5 is removed from the chuck cylinder 4, and the spring collet 15 is fitted to the shank 16 of the tool 1, and the tool 1 together with the spring collet 15 is fitted. The shank 16 is inserted into the cylindrical hole of the chuck portion 13. In this state, the tool 1 is fixed by rotating the tightening nut 5 clockwise.

  That is, the shank 16 of the tool 1 inserted into the cylindrical hole of the chuck portion 13 is tightened and gripped via the spring collet 15. Further, if the tightening nut 5 in the tightening state is rotated counterclockwise, the chuck nut 13 is loosened, the chuck portion 13 is restored to its original diameter, and the gripping force on the tool is released. Or it can be exchanged.

  FIG. 2 shows a case where the tool 1 is attached to the chuck portion 13 of the chuck cylinder 4 via the tightening nut 5. When the tool 1 is attached and fixed to the chuck cylinder 4 in this way, the taper shank shown in FIG. The upper end side fitting portion 12 of the chuck cylinder 4 is fitted into the fitting hole 7 of the portion 3. At this time, disc springs 17 and 17 are set on the upper end of the chuck cylinder 4 and combined with the taper shank portion 3, and the screw portion 10 of the pull stud 6 is screwed and attached.

  Therefore, the pull stud 6 is attached to the upper end of the tapered shank portion 3 so as to protrude, and the pull stud 6 is lifted by being locked to the lifting tool of the spindle 2 to form the attachment structure shown in FIG. In this case, if the pull stud 6 to which the screw hole 11 of the chuck cylinder 4 is screwed is lifted, the taper shank portion 3 is fitted into the hole of the spindle, and the upper end surface 18 of the tightening nut 5 is connected to the spindle. 2 is brought into contact with the lower end surface 19 and the clamping nut 5 and the spindle 2 are integrated.

1 shows an embodiment of a tool gripping chuck according to the present invention. When a tool is fixed to the chuck cylinder via a tightening nut. Conventional chuck for gripping tools.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tool 2 Spindle 3 Tapered shank part 4 Chuck cylinder 5 Tightening nut 6 Pull stud 7 Fitting hole 8 Insertion hole 9 Shaft part
10 Screw part
11 Screw holes
12 Mating part
13 Chuck part
14 Screw part
15 Spring collet
16 Shank
17 Belleville spring
18 Top surface
19 Bottom surface

Claims (3)

A chuck attached to a spindle of a machine tool for gripping a tool. A frustoconical tapered shank that fits into a hole in the spindle, and a fitting hole at the lower end that is concentric with the central axis of the tapered shank. The upper end of the chuck tube is inserted through the insertion hole to the upper end, and the fitting portion of the chuck cylinder is fitted in the fitting hole with the elastic material set at the upper end. Extends downward from the lower end of the taper shank, and its outer diameter is narrowed at the lower end. A screw is formed on the outer periphery of the chuck, and a tightening nut is screwed together. The screw part of the lower end of the pullstat that is suspended by being suspended by a hanging tool in the spindle is screwed into the hole, and a tool shank is fitted into the hole of the chuck part and fixed with a tightening nut. Craft Gripping chuck of. In a chuck structure that is attached to a spindle of a machine tool and grips a tool, the chuck for gripping the tool has a frustoconical tapered shank portion that fits into a hole in the spindle, and is concentric with the central axis of the tapered shank portion. The lower end is provided with a fitting hole and the upper end is penetrated by an insertion hole up to the upper end, and the fitting portion of the chuck cylinder is fitted in the fitting hole with an elastic material set at the upper end. The chuck part provided on the lower side extends downward from the lower end of the taper shank part, and its outer diameter is narrowed at the lower end side, and a threaded part is formed on the outer periphery of the chuck part, and a tightening nut is screwed together. The screw hole provided at the upper end of the shaft part is formed by screwing the screw part at the lower end of the pullstat that is suspended by being suspended by the hanging tool in the spindle, and a tool shank is fitted into the hole in the chuck part. Tightening Chuck structure of the tool with gripping chuck which is fixed by Tsu bets, and characterized in that the upper end face of the clamping nut abuts the spindle lower end face. 2. The chuck for gripping a tool according to claim 1, wherein a disc spring is used as the elastic material.

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