JPH0329051Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a chuck for gripping a rotary cutting tool such as a drill, and particularly a holding tube into which a rotary cutting tool or an adapter for holding the same is inserted; This invention relates to a roll lock type chuck in which a plurality of needle rollers are interposed between a tightening tube rotatably mounted on the outer circumferential surface of the chuck.

"Prior Art" Conventionally, as a chuck for gripping a rotary cutting tool, there is a holding cylinder into which the target tool is directly or indirectly inserted, and a chuck that is rotatably attached to the outer peripheral surface of the holding cylinder at a predetermined distance. A large number of needle rollers are arranged in multiple stages over the entire surface with axes that make an appropriate inclination angle with respect to these axes between the circumferential surface between the tightening tube and the tightening tube. A roll-lock type chuck in which the holding tube contracts and restores itself while the roller rotates and revolves around its axis is already known (Japanese Utility Model Publication No. 41-23987). Since the rotation of the holding cylinder is performed via a needle roller, the frictional resistance is lower than that of conventional products, and the operation can be carried out easily and smoothly.However, on the other hand, the wall thickness of the holding cylinder Since it is made thinner to increase the amount of contraction (deformation), it has a disadvantage that the chuck is weak and chatter occurs when performing powerful cutting due to its low rigidity, and furthermore, the shank of the holding cylinder and cutting tool is Because the holder is in contact with the entire circumferential surface of the holding cylinder, if the inner circumferential surface of the holding cylinder (the shank holding surface of the cutting tool) is operated with oil such as cutting oil attached, the inner circumferential surface may The oil film formed significantly reduced the holding force, causing the tool to slip and potentially making it virtually impossible to process.

In order to eliminate this drawback, it is sufficient to form a plurality of slits at predetermined intervals in the circumferential direction along the axial direction of the holding cylinder, but if such slits are formed, the tightening A problem arises in that one end of the needle roller that rolls due to the rotation of the attached tube falls into the plurality of slits or obstructs the rotational movement, making it impossible to rotate smoothly and spirally.

Therefore, in order to eliminate this drawback, a cylindrical holding cylinder (inner chuck cylinder) is constructed in which a plurality of slits are formed at predetermined intervals along the axial direction and in the circumferential direction.
A thin outer chuck tube having a tapered outer circumferential surface is fitted and fixed onto the outer circumferential surface of the chuck tube, and a needle roller is interposed between the outer chuck tube and the tightening tube. Proposed.
(Utility Model Publication No. 59-33534) ``Problems to be solved by the invention'' However, in this prior art, since a plurality of slits are formed in the inner chuck tube, the advantage is that the chuck tube can be easily deformed. However, since it is necessary to provide an outer chuck tube, not only does the number of parts increase accordingly, but it also has to be fitted and fixed concentrically to the inner chuck tube, which increases the cost and processing due to the increase in components. In addition to a decrease in accuracy and an increase in the number of assembly error factors, this method has the disadvantage of increasing the size and weight of the device itself.

The present invention solves the above-mentioned problems by making it easier to deform the holding cylinder into which the cutting tool shank or the adapter holding it is inserted, without increasing the number of parts, and while reducing the size of the device. The object of the present invention is to provide a chuck with improved cutting performance and increased gripping force.

"Means for Solving the Problems" The configuration of the chuck according to the present invention to achieve the above object of the invention is such that the chuck is arranged on the circumferential surface of the holding cylinder 11 in a direction that intersects with the axial direction of the needle roller 30 at a predetermined angle β. A plurality of through grooves 12 extending from the outer diameter to the inner diameter are formed so that the needle roller 30 that directly rolls on the outer peripheral surface of the holding cylinder 11 can roll without being hindered from rotating by the through grooves 12. At the same time, the through groove 12 is formed into a closed slit shape that does not open to the distal end surface of the holding cylinder 11, specifically, extends continuously or intermittently from the base side of the holding cylinder toward the distal end side, and the terminal end thereof is The structure consists of a closing slit that is fixed halfway to the tip end surface of the holding position.

In this case, in order for the needle roller 30 to roll without being hindered from rotating by the through groove 12, the intersection angle β between the through groove 12 and the axis of the needle roller 30, and the through groove For example, if the diameter of the needle roller 30 is around 2 mm, the slit width of the through groove 12 should be set to 0.5 mm or less (the diameter of the needle roller This can be easily achieved by setting the intersection angle β to approximately 3 to 5 degrees or more.

Further, by forming the through groove 12 wider on the inner diameter side than on the outer diameter side of the holding cylinder 11, it becomes possible to deform the holding cylinder 11 even more smoothly.

Note that the through groove 12 can be easily processed using a metal saw or the like, and may also be processed by electrical discharge machining, laser processing, or the like. It is preferable that a plurality of through grooves 12 be formed at predetermined intervals in the circumferential direction of the holding cylinder 11.

Furthermore, when machining is performed by electric discharge machining or laser machining, machining is performed while rotating the holding cylinder 11 in accordance with the inclination of the through groove 12 with respect to the axis. In other words, the cutting direction is always in the direction of the axis C. By machining while rotating the holding cylinder 11 so as to face the through groove 12 as shown in FIG.
is formed toward the axis C at any position, which is preferable from the viewpoint of machining and uniform deformation of the holding cylinder 11 itself.
In this case, the shape of the through groove 12 is not a straight line, but a slight helical curve.

"Operation" According to this technical means, the direction of the through groove 12 and the axial direction of the needle roller 30 are configured to intersect with each other, and the through groove 12 is configured so that the rotation of the needle roller 30 is not hindered. Therefore, even if the needle roller 30 directly rolls on the outer periphery of the holding tube 11 due to the rotation operation of the tightening tube 20, the needle roller 30 may fall off inside the through groove 12, or the needle roller 30 may fall inside the through groove 12. Therefore, the rolling of the needle roller 30 is not obstructed.

Further, the present technical means allows the through groove 12 to be inserted into the holding cylinder 1.
1, the holding cylinder 11 itself can be easily deformed, and the inner circumferential surface of the holding cylinder 11 is well drained of oil, which prevents the gripping force from decreasing. Since the cutting tool shank is not held on the entire circumferential surface, the gripping force is not dispersed.
Since the gripping force is locally concentrated in the axial direction, its strength is increased and it is possible to prevent the cutting tool from slipping.

Furthermore, according to the present technical means, the needle roller 30 directly rolls between the outer circumferential surface of the holding tube 11 and the inner circumferential surface of the tightening tube 20. It can be shrunk or restored, and therefore it is possible to reduce the number of parts and reduce costs, and it is also possible to eliminate error factors such as processing accuracy and assembly errors.

Further, according to the present technical means, the through groove 12
A closing slit 12 extends continuously or intermittently from the base side of the holding cylinder 11 toward the distal end side, and its terminal end is fixed at a position halfway to the distal end surface of the holding cylinder.
1. In other words, by providing the slit 121 in the middle of the holding cylinder 11 in the longitudinal direction, it is possible to easily deform the holding cylinder 11 while maintaining its strength. , compared to the case where the holding cylinder 11 is opened to the end face.
It is possible to improve the elastic force of the tool 1 itself, allowing quick restoration, and furthermore, it is possible to eliminate the risk of the tool end colliding with the open end of the through groove 12, causing breakage or damage to the tool. Become.

Furthermore, even when the through groove 12 is formed at an angle with respect to the axis as in the present technical means, compared to the case where it is formed parallel to the axis as in the prior art,
By setting the total length from the beginning to the end of the through groove to be the same, the force required to deform the holding cylinder 11 itself will not increase, and the vertical distance parallel to the axis will be shorter than in the prior art, resulting in high rigidity. Can be maintained.

Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, unless otherwise specifically stated, the dimensions, materials, shapes, and relative positions of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative. Just an example.

1 to 3 show an embodiment of the chuck according to the present invention, in which FIG. 1 is a longitudinal sectional front view, FIG. 2 is a plan view of the main part showing the holding cylinder 11, and FIG.
6A and 6B are main part sectional views showing the cross-sectional shape of the tip of the chuck; FIG. 6A shows the state before tightening, and FIG. 6B shows the state after tightening.

In the figure, 10 is a holder main body attached to the main shaft 2, and a shank 15 and a holding cylinder 11 are integrally formed along the axis C--C via a flange 14.

The holding cylinder 11 has a cylindrical inner circumferential surface 11b into which the cutting tool 1 as a target tool is inserted and held, either directly or via an adapter (not shown);
Outer peripheral surface 11a formed in a tapered shape from the base end
and an inner peripheral surface 20 around the outer peripheral surface 11a.
A tightening cylinder 20, which has a tapered surface similar in shape to the outer peripheral surface 11a of the holding cylinder, is rotatably mounted so as to remain at a predetermined distance.

A large number of needle rollers 30 are rotatably held at predetermined positions by roller gauges 31 within the circumferential distance between the inner circumferential surface 20a of the tightening tube 20 and the outer circumferential surface 11a of the holding tube 11 of the holder body. , are arranged in multiple stages around the entire circumference, and the arrangement direction of the needle rollers 30 is inclined with respect to the axis C-C of the tightening cylinder 20 and the holding cylinder 11, as shown in FIG. They are arranged along an axial direction with an angle α.

In addition, 13 and 22 are retaining rings, and these are located on the circumferential surfaces 11a and 20a of the holding cylinder 11 and the tightening cylinder 20, respectively.
The roller gauge 31 is attached to the roller gauge 31 to restrict movement of the roller gauge 31 in the axial direction.

Further, a seal ring 40 formed of an annular metal ring is interposed between the retaining ring 13 and the roller gauge 31, as shown in FIGS. 6A and 6B.

The seal ring 40 has its outer diameter tightened to the cylinder inner diameter 2.
0a (see Fig. 6A), and when the tightening cylinder 20 is operated to tighten and move in the axial direction, it comes into contact with this inner diameter surface 20a, and external dust is mixed into the roller housing section. It prevents you from doing so.
(See Figure 6B) Although the inner diameter side of the ring 40 has a large gap with respect to the groove of the holding cylinder 11, since it comes into contact with the retaining ring 13, it can be processed and processed without deteriorating the sealing performance. This makes it easy to wear.

According to this configuration, as is known, by rotating the tightening tube 20 in the forward and reverse directions, the needle roller 30 rotates on its own axis and revolves in a spiral manner, so that the holding tube 11 can be contracted or restored.

Now, in this embodiment, as shown in FIG. 2 and FIG.
Four slit penetration grooves 12 reaching from the outer circumferential surface 11a to the inner circumferential surface 11b of 1 are formed at equal intervals with a phase shift of 90 degrees in the circumferential direction.

The through groove 12 is a closed slit-like structure that is displaced from the vicinity of the base of the holding cylinder 11 by a predetermined angle with respect to the axis C-C and extends substantially in a straight line, and is fixed at a position near the tip of the holding cylinder. 11, the intersection angle β between the needle roller 30 and the through groove 12 is set to be greater than or equal to the inclination angle α between the axes of both cylindrical bodies 11 and 20 and the axis of the needle roller 30,
For example, it is formed in the shape of a closed slit set at around 3° to 5°, and the slit width of the through groove 12 is formed to be considerably narrower than the diameter (2 mm) of the needle roller 30, for example, 0.5 mm or less.

Thus, according to such an embodiment, the through groove 12
Since the direction of the needle roller 30 and the axial direction of the needle roller 30 have the above-mentioned positional relationship, and the slit width of the through groove 12 is set to be considerably narrower than the diameter of the needle roller 30, the rotation of the tightening cylinder 20 allows the needle to be Even when the roller 30 directly rolls on the outer peripheral surface 11a of the holding cylinder 11, the movement of the needle roller 30 is not hindered by the groove of the through groove 12, and smooth rolling is possible.

In addition, in the above embodiment, the needle roller 30
The inclination angle α with respect to the axis is set to an angle necessary for the needle roller 30 to smoothly revolve helically, for example, 1 to 2 degrees.

Further, the through groove 12 is
By machining by electric discharge machining or laser machining while rotating the holding cylinder 11 in accordance with the inclination of This is preferable from the viewpoint of uniform deformation of the holding cylinder 11 itself and from the viewpoint of processing.

Furthermore, in the above-mentioned processing method, the shape of the through groove 12 becomes a slight helical curve, so that the movement of the needle roller 30 is not hindered more than in the case of a straight through groove 12, and the movement of the needle roller 30 is made smoother. Rolling is possible.

4 and 5 show other embodiments showing modifications of the through groove 12 formed in the holding cylinder 11. FIG. 4 is a plan view of the main part, and FIG. FIG.

In the figure, the same members as those in the embodiment described above are given the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, the through groove 121 is formed in the longitudinal middle part of the holding cylinder 11 as shown in FIG. 2, and the inner diameter side 11b is wider than the outer diameter side 11a as shown in FIG. is formed. This has the advantage of being easier to deform compared to a structure in which the outer diameter side 121a and the inner diameter side 121b are communicated with each other with the same width.

"Effects of the invention" As described above, according to the invention, it is possible to downsize the device without increasing the number of parts.
It is possible to easily deform the cutting tool shank or the holding cylinder into which the adapter holding the same is inserted, and to improve oil drainage and increase the gripping force.
In particular, by forming the through groove into a closed slit shape that does not open to the end surface of the holding cylinder, the holding cylinder 11 can be easily deformed while maintaining its strength.

Furthermore, by filling the through groove with an elastic agent such as rubber to block communication between the inner diameter side and the outer diameter side, it is possible to prevent dust from entering the roller rolling surface. When applied to chucks used in machining or other processing methods that generate many fine cutting chips, its practical value will be extremely large and it will be effective.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the chuck according to the present invention, in which FIG. 1 is a longitudinal sectional front view, FIG. 2 is a plan view of the main part showing the holding cylinder 11, and FIG. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 2; 4 and 5 show other embodiments showing modified examples of the through groove formed in the holding cylinder. FIG. 4 is a plan view of the main part, and FIG. 5 is a view of FIG. FIG. 6A and 6B are main part sectional views showing the cross-sectional shape of the tip of the chuck, with FIG. 6A showing the state before tightening and FIG. 6B showing the state after tightening. 11: Holding cylinder, 11a: Outer peripheral surface, 12, 12
1: Penetration groove, 20: Tightening tube, 20a: Inner peripheral surface, 3
0: Needle roller.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A holding cylinder into which a target tool is directly or indirectly inserted, a tightening cylinder that is rotatably attached to the outer peripheral surface of the holding cylinder and remaining at a predetermined distance, and both cylinders. In a chuck having a large number of needle rollers interposed between peripheral surfaces, the holding cylinder contracts and restores while the needle rollers rotate and revolve helically due to the rotation of the tightening cylinder, A plurality of through grooves extending from the outer diameter to the inner diameter are formed on the circumferential surface of the holding cylinder in a direction that intersects the axial direction of the needle roller at a predetermined angle, and the needle roller that directly rolls on the outer circumferential surface of the holding cylinder is configured to What is claimed is: 1. A chuck characterized in that the chuck is configured to be able to roll without being hindered from rotating on its axis by the groove, and the through groove is formed in the shape of a closed slit that does not open to the distal end surface of the holding cylinder. 2. Utility model registration claim 1, in which the slit width of the through groove is set to approximately 1/4 or less of the diameter of the needle roller, and the intersection angle between the through groove and the axis of the needle roller is set to approximately 3° or more. Check the section. 3. The chuck according to claim 1, wherein the through groove is formed wider on the inner diameter side than on the outer diameter side of the holding cylinder. 4. The chuck according to claim 1, wherein the through groove is filled with an elastic agent such as rubber to block communication between the inner diameter side and the outer diameter side.