JPH0115446Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention is a needle roller type chuck for attaching cutting tools, etc. to the main shaft of a machine.

[Prior art and its problems] Conventionally, as shown in FIG. 3, a needle roller type chuck has a cylindrical body 2 whose outer peripheral surface is tapered and extends in front of a chuck body 1. A tightening nut 3 having a parallel taper formed on the inner circumferential surface with a diameter slightly larger than that of the outer circumferential surface of the cylinder body 2 is attached to the outer circumferential surface of the cylindrical body 2 via a number of needle rollers 5 rotatably held by a retainer 4. (Refer to Utility Model Publication No. 41-23987). In this device, the needle rollers 5 are arranged so that their axis x does not intersect with the axis The cylinder body 2 is contracted and restored, and the tool 6 is attached and detached.

However, in this case, there is a gap 7 between the cylindrical body 2 and the rear part of the tightening nut 3 due to the presence of the needle roller 5, and chips, dust, cutting fluid, etc. can enter from this part. This has the problem of impairing the durability of the cylinder 2, the tightening nut 3, and the needle roller 5. Another problem is that even if the needle roller mounting portion is filled with grease, it will leak from the gap 7.

[Means for Solving the Problems] Therefore, the needle roller type chuck according to the present invention has an annular collar fixed to the chuck body and an annular collar fixed to the rear part of the tightening nut that slide in the axial direction. A sealing member is attached to the sliding portion of the chuck, and a sealing member is attached to the tip of the cylindrical body and the tightening nut to seal the needle roller attachment portion. It is characterized by forming a grease injection hole that communicates with the.

[Example] In FIGS. 1 and 2, the present needle roller type chuck generally includes a chuck main body 10, an outer cylinder 20 fixed to the outer peripheral surface of an inner cylinder 15 extending in front of the chuck main body 10, and , a needle roller 30 held by a retainer 25, a tightening nut 35 attached to the outer peripheral surface of the outer cylinder 20 via the needle roller 30, and collars 40, 41, and the cylinder body is a chucking part. is divided into an inner cylinder 15 and an outer cylinder 20.

The chuck body 10 is integrally formed with a shank portion 11 at the rear and an inner cylinder 15 at the front.
A plurality of grooves 16 are formed at equal intervals in the axial direction on the outer circumferential surface. This groove portion 16 has a length corresponding to the mounting portion of the needle roller 30, and its distal end portion is fixed to the distal end surface of the inner cylinder 15 without opening, and is communicated with the annular groove portion 17.

The outer cylinder 20 is made of, for example, chromium molybdenum steel, bearing steel, etc., has a flange portion 21 at the rear end, and has a tapered outer peripheral surface. The outer cylinder 20 is firmly integrated with the chuck main body 10 by fitting onto the outer circumferential surface of the inner cylinder 15 using, for example, a shrink fit method.

The retainer 25 is a thin cylindrical body having a taper parallel to the outer peripheral surface of the outer cylinder 20, and is rotatably mounted on the outer peripheral surface of the outer cylinder 20. The needle rollers 30 are placed one by one in the grooves of the retainer 25 and are rotatable, and are arranged so that their axes do not intersect with the axis of the chuck body 10 but are inclined.

The tightening nut 35 has an inner circumferential surface slightly larger in diameter than the outer circumferential surface of the outer cylinder 20 and has a parallel taper, and is rotatably mounted on the outer circumferential surface of the outer cylinder 20 via the needle roller 30.

The retainer 25 is prevented from coming off by a retaining ring 22 provided at the tip of the outer peripheral surface of the outer cylinder 20 via a seal rubber 23 and spacers 24a, 24b, and the tightening nut 35 is secured by a retaining ring 38 provided at the rear end of the inner peripheral surface. is prevented from coming off by coming into contact with the rear end of the retainer 25 via the spacer 39. That is, the outer cylinder 2
0 and the tip of the tightening nut 35 is the seal rubber 23
The inner peripheral surface of the tightening nut 35 is slidable on the seal rubber 23 in the axial direction.

The collar 40 is an annular body made of metal or resin, and is fitted and fixed (adhered if necessary) to the outer peripheral surface of the flange portion 21 of the outer cylinder 20. The other collar 41 is an annular body made of metal or resin. It is fitted and fixed (adhered if necessary) to the rear end step of the outer circumferential surface of the tightening nut 35, and both are capable of sliding in the axial direction with respect to each other on the inner circumferential surface and the outer circumferential surface. This sliding portion is sealed with an O-ring 42 attached to a collar 41. Also, color 4
The outer circumferential surface 41a of No. 1 is color-coded in the axial direction along lines A in FIG. That is, the collar 41 moves the tightening nut 35 in the axial direction (tool 50 described below).
The degree of tightening can be confirmed by visually observing the degree to which the end portion 40a of the collar 40 covers the color-coded outer peripheral surface 41a.

Furthermore, the threaded hole 18 formed on the outer peripheral surface of the chuck body 10 connects the outer cylinder 20, which is the needle roller mounting part, and the tightening nut 35 through the hole 18a and the hole 21a formed in the flange part 21 of the outer cylinder 20.
There is communication between the two. This screw hole 18 is for applying grease to the needle roller attachment part, and is normally sealed with a setting screw 19. When grease is applied, the setting screw 19 is sealed.
Insert a grease nipple into the screw hole 18 that was removed and inject grease. As described above, the needle roller mounting portion is sealed with the seal rubber 23 and the O-ring 42. Note that filling with grease is impossible if the needle roller mounting portion is completely sealed at the time of filling up the grease. Therefore, another screw hole is formed at a position symmetrical (180°) to the screw hole 18 and communicates with the needle roller attachment part, and this screw hole is opened when the grease is applied.
Others are kept sealed.

The present needle roller type chuck having the above configuration is installed by inserting the chuck body 10 into the center hole 61 of the machine main shaft 60 by inserting the shank part 11, and if necessary, adjusts the adjusting screw 5.
2 is attached to the threaded portion 12, and the shank portion 51 of the tool 50 is inserted into the center hole 13 via the straight collet 53. Next, tighten the tightening nut 35
When rotated, the needle roller 30 rotates on its own axis and revolves in a spiral shape, moves backward together with the tightening nut 35, and the outer cylinder 20 and inner cylinder 15 contract inward,
The tool 50 is chucked through the straight collet 53. Note that FIGS. 1 and 2 show this chucking state.

The tool 50 can be removed by rotating the tightening nut 35 in the opposite direction.

The tightening nut 35 is rotated by engaging a protrusion of a dedicated spanner in the recess 36 of the tightening nut 35.

The needle roller type chuck according to the present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the gist.

For example, the O-ring 42 may be provided on the inner peripheral surface of the collar 40, or the collar 41 may be located outside the collar 40. The seal member is not necessarily limited to the O-ring 42 or the seal rubber 23.

Furthermore, in this embodiment, the outer circumferential surface of the collar 41 is color-coded in the axial direction as an indicator of the tightening force exerted by the tightening nut 35. According to this, the degree of tightening can be seen at a glance. By shortening the lifespan of the rollers, needle rollers 30, etc., these problems can be eliminated. Furthermore, the chuck main body 10 may be formed by integrating the inner cylinder 15 and the outer cylinder 20. However, if the chuck is divided into two parts, the material and hardness of the outer cylinder 20 can be changed from those of the chuck main body 10, thereby improving the durability of the chuck itself.

[Effects of the invention] As is clear from the above explanation, according to the invention, it is possible to reliably seal the tip of the needle roller attachment part and the rear end, which was left as a gap in the past, and to prevent chips and It is possible to prevent the intrusion of dust, cutting fluid, etc., and maintain sufficient durability of the needle roller, etc. Furthermore, the needle roller mounting portion can be greased from the chuck body, and since the needle roller mounting portion is sealed, there is no grease leakage, and durability can be further improved.

[Brief explanation of drawings]

FIG. 1 is a half-sectional view showing an embodiment of a needle roller type chuck according to the present invention, and FIG. 2 is a partially cutaway perspective view thereof. FIG. 3 is a sectional view of a conventional needle roller chuck. 10...chuck body, 15...inner cylinder, 18...
...Screw hole, 18a...hole, 20...outer cylinder, 20a
... Hole, 23 ... Seal rubber, 25 ... Retainer, 30 ... Needle roller, 35 ... Tightening nut, 40, 41 ... Collar, 42 ... O-ring.

Claims (1)

[Claims for Utility Model Registration] A tightening system in which a cylindrical body with a tapered outer circumferential surface extends in front of the chuck body, and a parallel taper with a diameter slightly larger than the outer circumferential surface of the cylindrical body is formed on the inner circumferential surface. In a needle roller type chuck in which a nut is attached to the outer peripheral surface of the cylindrical body via a number of needle rollers rotatably held by a retainer, an annular collar fixed to the chuck body and a rear part of the tightening nut are connected to each other. A fixed annular collar is slidably overlapped in the axial direction, a sealing member is attached to the sliding part, and a sealing member is attached to the tip of the cylinder body and the tightening nut to form a needle roller mounting part. A needle roller type chuck characterized in that, while being sealed, a grease injection hole communicating with the needle roller mounting portion is formed in the chuck body.