JPH04122407U - chuck for tools - Google Patents

Abstract

(57) [Summary] [Purpose] Automatically correct the inclination of the pawl opening/closing screw shaft to prevent tool axis runout. [Configuration] Tool holder 3 with a hollow shaft 2 at the tip
a connecting sleeve 5 which has a female threaded portion 4 therein and is fitted and fixed into the hollow shaft portion 2; and a pawl which is screwed into the female threaded portion 4 so as to be able to move forward and backward and has a pawl engagement groove 29 on the tip surface 28. Opening/closing screw shaft
6 and is rotatably fitted onto the connecting sleeve 5 and has a tapered cone-shaped portion 38 at its tip, and the cone-shaped portion 38
It consists of a claw opening/closing holding cylinder 12 having a claw fitting groove 39 on its inner surface, and a plurality of tool gripping claws 13 which are fitted into the claw engaging groove 29 of the screw shaft 6 and expand and contract by sliding in the axial direction. The claw opening/closing screw shaft
The distal end surface 28 of 6 is a plane perpendicular to the axis.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention can grip tools with straight shanks such as drills and end mills. This invention relates to a chuck for tools.

0002

[Conventional technology]

Tool chuck for attaching cutting tools such as drills to the spindle of machine tools Of these, cutting oil can be supplied from the oil supply path on the machine tool side to the drill with an oil hole. A chuck holder is known (for example, see Utility Model Publication No. 2-26604). (See).

0003 The holder consists of a holder shank that is attached to the spindle of a machine tool, and a A holder case that is fitted around the outer periphery of the hollow shaft at the tip of the shank so that it can rotate relative to the outside, and a It consists of a chuck body fitted to the tip of the hollow shaft part, and an oil supply path in the holder case. is formed, and one end of the oil feed path is connected to the oil supply source via a fixed member on the machine tool side. The other end of the oil passage is connected to the drill with an oil hole through the chuck body. Ru.

0004 The chuck body 60 is attached to the hollow shaft portion 61 of the tool holder, as illustrated in FIG. The connecting sleeve 62 that is fitted and fixed, and the female threaded portion 63 at the inner end of the sleeve 62 can be moved forward and backward. A claw opening/closing screw shaft 64 is screwed into the sleeve 62, and a ring nut 65 is attached to the outer periphery of the sleeve 62. An outer cylinder 66 is rotatably fitted on the outside, and a claw opening/closing retainer is fitted and fixed on the tip of the outer cylinder 66. The holding cylinder 67, the engagement groove 68 at the tip of the pawl opening/closing screw shaft 64, and the tapering of the pawl opening/closing holding cylinder 67. It consists of a plurality of gripping claws 71 fitted into claw fitting grooves 70 provided on the inner surface 69 of the cone. The end surface of the opening/closing screw shaft 64 is a conical concave surface 72, and a drill with an oil hole is formed on the concave surface 72. The end surface 75 of the straight shank portion 74 of the lever 73 is brought into contact with the straight shank portion 74 of the lever 73. and, By rotating the claw opening/closing holding cylinder 67, the claw opening/closing screw shaft is opened via the gripping claw 71. 64 moves forward and backward in the axial direction, and the gripping claws 72 are expanded by the cone-shaped inner surface 72. The shank portion 74 is gripped or released by contracting (opening and closing).

[0005]

[Problem that the idea aims to solve]

By the way, the claw opening/closing screw shaft 64 of the chuck main body 60 explained in the conventional example can be moved forward and backward. In order to increase the gap between the connecting sleeve 62 and the female threaded part 63, it should be made into a triangular thread. Therefore, the gripping claw 71 holds the shank part 74 of the tool straight (the central axis of the hollow shaft part 61 Even if it is gripped with A conical concave surface 72 contacts 75. However, the cone-shaped concave surface 72 of the pawl opening/closing screw shaft 64 is Even when pressed against the end face 75 of the trunk portion 74, the screw shaft 64 remains tilted. The end face 75 of the shank portion 74 is pushed without being corrected, and as a result, The axis line of the drill 73 does not match the axis line of the holder shank, which tends to cause axis runout. There is a problem.

[0006] This invention was made in view of the above-mentioned circumstances, and its purpose is to is a tool that can automatically correct the inclination of the claw opening/closing screw shaft and prevent the tool from running out. To provide a chuck for use.

[0007]

[Means to solve the problem]

In order to achieve the above object, the present invention takes the following technical measures. That is, books The idea is to have a tool holder with a hollow shaft at the tip and a female thread inside. A connecting sleeve is fitted and fixed into the hollow shaft portion and is screwed into the female thread portion so as to be freely retractable. A claw opening/closing screw shaft having a claw engaging portion on the tip surface, and a rotatable claw shaft attached to the sleeve. At the same time as forming a tapered cone-shaped part on the inner surface of the tip, and forming a tapered cone-shaped part on the inner surface of the tip part, A claw opening/closing holding cylinder provided with a claw engaging portion engages with the claw engaging portion of the screw shaft and A plurality of tool gripping claws that fit into the claw fitting portion of the holding cylinder and expand and contract by sliding in the axial direction. characterized in that the tip surface of the claw opening/closing screw shaft is a plane perpendicular to the axis. It is a sign.

[0008]

[Effect] According to the present invention, the straight shank portion 31 of the tool 30 is inserted between the gripping claws 13 in the open state. the claw opening/closing screw shaft 5, and bring it into contact with the flat end surface 28 of the claw opening/closing screw shaft 5, and move the claw opening/closing holding cylinder 12 in the closing direction. When the gripping claws 13 are rotated to The screw shaft 6 advances to the tip side and pushes each gripping claw 13 and tool 30. Extrude toward the tip. This causes each gripping pawl 13 to move radially inward and hold the tool 30. While holding it straight, the end face 32 of the shank part 31 of the tool 30 is aligned with the tip of the screw shaft 6. Since it is in pressure contact with the surface 28, the inclination of the screw shaft 6 is corrected, and the screw shaft 6 and the machining Both ends of the tool 30 are aligned. Therefore, no axial runout of the tool 30 occurs. In addition, the engineering When removing the tool 30 from the chuck 1, rotate the jaw opening/closing holding cylinder 12 in the opening direction. As a result, the pawl opening/closing screw shaft 6 rotates and retracts, and each gripping pawl 13 retracts and moves in the radial direction. It moves outward and opens.

[0009]

【Example】

Hereinafter, embodiments of the present invention will be described based on the drawings. In Figure 1, tool chuck 1 is suitable for oil hole drills and has a hollow shaft at the tip. A tool holder 3 having a section 2 and a female thread section 4 inside the hollow shaft section 2. The connecting sleeve 5 is fitted into and fixed to the connecting sleeve 5, and the claw opening/closing screw is screwed into the female threaded part 4 so that it can move forward and backward. A screw shaft 6 and a holder fitted onto the hollow shaft portion 2 through bearings 7 and 8 so as to be relatively rotatable. A ring nut 10 is attached to the outer periphery of the case 9 and the sleeve 5 so that the sleeve 5 can be rotated freely and An outer cylinder 11 that is not movable in the axial direction, and a claw opening whose rear end is externally fitted and fixed to the outer cylinder 11. It mainly consists of a closed holding cylinder 12 and three gripping claws 13 housed within the cylinder 12.

0010 The rear part of the holder 3 is fitted and fixed into the spindle of the machine tool (not shown). A gripping part 15 of the automatic tool changer is concentrically arranged between the shank part 14 and the shaft part 2. It is fixed on the outside. The hollow shaft part 2 has a tapered inner surface that widens at the end. A shaped sleeve fitting part 16 is formed, and its outer end is enlarged in diameter to form an outer cylinder fitting part 17. , an oil passage 18 is provided between the fitting parts of both bearings 7 and 8, and a screw is provided behind the sleeve fitting part 16. A plug 19 is screwed into the sleeve fixing screw hole 20 on the front end side of the front oil passage 18. It is provided so as to penetrate the inner surface of the joint portion 16.

[0011] The connecting sleeve 5 is arranged so that the rear end of its outer surface becomes narrower toward the rear end. A tapered surface 21 corresponds to the fitting portion 16, and approximately the front half of the inner surface is a female threaded portion 4. The claw opening/closing screw shaft 6 is screwed so that it can move forward and backward. In addition, the sleeve 5 On the outer circumferential surface, an outer cylinder locking collar 22 is protruded at the front end, and a tapered locking pin is installed at the rear end. The hole 24 is slightly eccentric toward the tip in correspondence with the sleeve fixing screw hole 20 of the hollow shaft portion 2. A fixing screw 26 with a tapered locking pin 25 eccentrically provided at the tip. It is fixed to the hollow shaft part 2 by. Note that the female threaded portion 4 is curved. The inclination of the claw opening/closing screw shaft 6 that is screwed into the wire thread can be easily corrected. It looks like this.

0012 The pawl opening/closing screw shaft 6 is hollow, and its threaded portion 27 is a curved thread, which is The inclination when screwed into the female thread part 4 so that it can move forward and backward can be easily corrected. , the diameter of the tip is expanded so that the tip surface 28 is a flat surface perpendicular to the screw axis, forming a T-shaped Three pawl engagement grooves 29 are provided at equal angles in the radial direction, and the tool 30 is provided on the flat tip surface 28. The end face 32 of the straight shank 31 is brought into contact with it.

[0013] The ring nut 10 has a threaded portion 33 on its outer periphery, and a rear end portion of the inner surface of the outer cylinder 11. The outer cylinder locking collar 22 is screwed into the internal threaded part 34 provided in the An outer cylinder 11 is fitted around the sleeve 5 so as to be rotatable but immovable in the axial direction. There is. 36 is a seal ring externally fitted and fixed to the rear end of the outer peripheral surface of the outer cylinder 11; The ring 36 is in sliding contact with the outer cylinder fitting part 17 of the hollow shaft part 2. Also, the front end of the outer peripheral surface of the outer cylinder 11 is compressed. The rear end portion of the claw opening/closing holding cylinder 12 is externally fitted and fixed to the diameter portion 37.

[0014] The front half of the claw opening/closing holding cylinder 12 has a tapered cone-shaped portion 38, and the inner surface 38 Three pawl fitting grooves 39 are provided in a, and the gripping pawl 13 can freely slide in the axial direction into each groove 39. is mated to. Note that each gripping claw 13 is provided with an engaging protrusion 40 having a T-shaped cross section at the rear end. The engaging protrusion 40 slides radially into the pawl engaging groove 29 at the front end of the pawl opening/closing screw shaft 6. freely engaged. In addition, a notch for the opening/closing handle is provided on the outer periphery of the claw opening/closing holding cylinder 12. A large number of recesses 41 are provided.

[0015] The retainers 42 and 43 of the bearings 7 and 8 have cross-shaped cross sections, and are arranged inside facing each other. between the inner circumferential surfaces of the protruding cylindrical portions 44, 45 and the outer circumferential surface of the hollow shaft portion 2. Seal rings 46, 47 are fitted into the bearing fitting sleeves 48, 49 and the cylindrical sleeves 48, 49, respectively. Seal rings 50, 51 are fitted between the outer peripheral surfaces of the parts 44, 45, respectively. Said The retainers 42 and 43 each have the hollow shaft portion 2 on the inner surface of the axially central portion of the holder case 9. It is partitioned off by an inner flange 52 that is fitted into the inner flange 52.

[0016] The inner circumferential surface of the inner flange portion 52 of the holder case 9 has a groove corresponding to the oil passage 18 of the hollow shaft portion 2. An oil passage 53 consisting of an annular groove is provided, and an oil supply hole 54 is connected to the oil passage 53. Further, a case rotation prevention member 56 equipped with an oil passage opening/closing valve 55 is connected to the entrance of the oil supply hole 54. The case rotation prevention member 56 is connected to a rigid shaft that pivotally supports the spindle of the machine tool. Detachably connected to the oil passage connection attachment (not shown) attached to the fixed member. It is now possible to do so. Therefore, the holder case 9 can be It serves to guide cutting oil to the oil hole 57 of the tool 30. In addition, 58 is a ball, 59 is the bearing cover.

[0017] In the above embodiment, the oil supply hole 54 of the holder case 9 is connected to the hollow shaft portion from the oil passage 53. 2, the oil passage 18 of the tool 30, the connection sleeve 5 and the hollow claw opening/closing screw shaft 6. It communicates with the oil hole 57 so that cutting oil etc. can be guided to the tip of the tool 30. , the holder case 9 is restrained by a fixed member that pivotally supports the spindle of the machine tool and rotates. The holder 3 rotates at high speed via the bearings 7 and 8.

[0018] When attaching the tool 30 to the chuck 1, first rotate the jaw opening/closing holding cylinder 12 to the right. When the gripping claws 13 and the claw opening/closing screw shaft 6 are rotated together, the screw shaft 6 is retracted. In order to At the same time as it retracts, the spacing between each claw 13 is widened to become an open state. So, the tool 30 stroke Insert the rate shank part 31 between each gripping claw 13 and insert its end face 32 into the claw opening/closing screw shaft 6. When the claw opening/closing holding cylinder 12 is rotated to the left while touching the tip surface 28, each gripping claw 13 and The claw opening/closing screw shaft 6 rotates integrally, and as the screw shaft 6 advances toward the tip side, , each of the gripping claws 13 is slid axially outward to narrow the gap between them to close the shank of the tool 30. Hold the portion 31 straight and concentrically with the axis of the hollow shaft portion 2. At this time, the tool 30 Since the shank end face 32 is in pressure contact with the tip face 28 of the screw shaft 6, the screw shaft 6 The inclination of is corrected, and the axes of the screw shaft 6 and the tool 30 are aligned. Therefore, The axial runout of the tool 30 is completely eliminated. Note that when removing tool 30 from chuck 1, If so, rotate the claw opening/closing holding cylinder 12 clockwise to open each gripping claw as described above. 13 is opened, and the tool 30 can be pulled out.

[0019] Further, according to the above embodiment, the protruding cylindrical portions 44, 45 of the respective retainers 42, 43 of the bearings 7, 8 Seal rings 46, 47, 50, 51 are installed on both the inner and outer peripheral surfaces of the retainer 42. , 43, the seal rings 46, 47, 50, 51 rotate in the same direction as the hollow shaft portion 2. Immediately When the hollow shaft portion 2 rotates once, the retainers 42 and 43 rotate by half a rotation via the balls 58. Circumferential speed is halved. Therefore, oil leakage, wear, etc. of seal rings 46, 47, 50, 51 are prevented. The rotational speed of the hollow shaft portion 2, that is, the tool 30, can be increased to the allowable circumferential speed due to the It can be doubled compared to those with a seal structure, and allows the tool to rotate at high speed. I can do that.

[0020] The present invention is not limited to the above embodiments, but includes, for example, a door with an oil hole. Used in chucks for tools other than drills (including tools without oil holes). can be done.

[0021]

[Effect of the idea]

As mentioned above, the present invention has a tool holder with a hollow shaft at the tip and a a connecting sleeve having a female threaded portion and fitted and fixed into the hollow shaft portion; a pawl opening/closing screw shaft screwed into the same portion so as to be freely retractable and having a pawl engaging portion on the tip surface; It is rotatably fitted onto the sleeve and a tapered cone-shaped part is formed on the inner surface of the tip. and a claw opening/closing holding cylinder having a claw fitting part on the cone-shaped part, and a claw engaging part of the screw shaft. When engaged, the compound is fitted into the claw fitting portion of the holding cylinder and slid in the axial direction to expand and contract. It consists of several tool gripping claws, and the tip surface of the claw opening/closing screw shaft is perpendicular to the axis. Because it is flat, the inclination of the claw opening/closing screw shaft can be adjusted with high precision. It is automatically corrected by the end face of the tool being centered, and the tool and pawl opening/closing screw shaft are Both center axes are aligned, preventing the tool from running out. Therefore, increased tool life It is possible to improve machining accuracy.

[Brief explanation of drawings]

FIG. 1 is a partially omitted vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view showing main parts of a conventional example.

[Explanation of symbols]

1 Tool chuck 2 Hollow shaft part 3 Holder 4 Female thread part 5 Connecting sleeve 6 Claw opening/closing screw shaft 12 Claw opening/closing holding cylinder 13 Holding claw 28 Tip surface 29 Claw engagement groove (claw engagement part) 30 Tools 38 Cone-shaped part 39 Claw fitting groove (claw fitting part)

Claims (1)

[Scope of utility model registration request] 1. A tool holder having a hollow shaft at its tip, a connecting sleeve having a female thread inside and fitted and fixed into the hollow shaft, and a connecting sleeve screwed into the female thread so as to be freely retractable and retractable. a claw opening/closing screw shaft having a claw engaging portion on the tip surface;
A claw opening/closing holding cylinder is rotatably fitted onto the sleeve and has a tapered cone-shaped portion formed on the inner surface of the tip end, and a claw-fitting portion is provided in the cone-shaped portion; It consists of a plurality of tool gripping pawls that are fitted into the pawl fitting portion of the holding cylinder and expand and contract by sliding in the axial direction, and the tip surface of the pawl opening/closing screw shaft is perpendicular to the axis. A tool chuck characterized by its flat surface.