JPS5815043Y2 - Check - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a chuck for gripping and holding tools such as drills and end mills.

As is well known, a large number of inclined needle rollers are inserted between the chuck cylinder protruding from the tip of the chuck body and the tightening operation cylinder provided in a surrounding manner around the outer periphery of the chuck body. Therefore, there is a chuck that grips a mating tool by elastically contracting the chuck tube, and this type of chuck allows chucking with extremely smooth operation.

However, in conventional chucks, the chuck tube for gripping the tool has a continuous inner surface on the inner periphery so as to grip the entire circumference of the tool, so even if the chuck tube is tightened to a certain torque, Coupled with the fact that the tool was directly opposed to the inner periphery of the cylinder itself and was tightened to restrict axial deformation (evacuation), the chuck cylinder itself was in a state where it was difficult to shorten. It is.

As a result, the chuck tube acts as a resistor that strongly repulses, so it immediately becomes tightened, but in reality, it is only tightened through the roller, and there is no resistor between the chuck tube and the tool. The tool is hardly tightened due to the action, and the tool is held in place only by the friction caused by the low surface pressure, and it does not have a strong biting relationship, so it often slips when an impactful cutting load is applied. It was done.

This occurred relatively frequently, partly because the tightening torque used by the person performing the tightening work varied in magnitude.

Taking this into consideration, it is customary to configure the chuck tube itself with a thin-walled tube that can be expanded and contracted more easily, but this makes tightening a little easier (this improves the chuck performance itself, but the thinner wall makes it easier to tighten the chuck tube). Also, because the body is weak and easily bent, the axis of the gripped tool swings considerably, resulting in a four-slope field when attempting to achieve high precision in machining. It is.

This invention was devised to solve the above problem, and its purpose is to prevent the inconvenience of the tool from stopping during work by gripping the tool extremely reliably by the chuck tube that tends to shrink. In addition, since the chuck tube tends to shrink, the present invention aims to provide a chuck in which the thickness of the chuck tube is further increased so that the center runout of the tool can be kept to a small to medium level. explain.

As shown in FIGS. 1 to 3, a chuck body 1 has a flange-shaped loading seat 2 protruding from the axially intermediate portion thereof, and a check cylinder 3 integrally protruding from the front end thereof.

The cylinder 3 has a base on the catch seat 2 side that projects outward in a thick inner shape, and a guide surface 4 is provided around this part, and the outer periphery of most of the tip side is tapered and continuous in the circumferential direction. It has a cylindrical surface.

Reference numeral 5 denotes the outermost tightening operation cylinder, which is provided so as to surround the entire chuck cylinder 3 with its base inner circumference connected to the guide surface 4.

Here, 6 is a lock operation port provided around the circumference in the shape of a recess, and 1 is a rotation operation section.

The inner periphery of the chuck tube 3 is also tapered, and there is a certain tapered space between it and the chuck tube 3, and the retainer 8 is installed in this space, and a large number of needle rollers are inserted into the loading port of the retainer 8. Groups 9 are arranged, and the rollers 9 are arranged at a slight inclination so that the roller axes are positioned clockwise in FIG. .

When the tool 10 is inserted in this way and the operation cylinder 5 is rotated, the chuck cylinder 3 is contracted by the above-mentioned landing and returns by reverse rotation.

Under these circumstances, the chuck tube 3 itself is made about twice as thick as the conventional one, <t, and the vertical grooves 11 are formed in the straight inner circumferential wall to make the gripping state stronger. This groove 11 is formed between the outer peripheral surface of the chuck tube 3 and the groove bottom 11a.
The groove 11 is formed into a semi-cylindrical shape so as to leave a wall thickness t2 of about 0.4 to 0.5 tl between the chuck tube 3 and the chuck tube 3 when the longitudinal direction of the groove 11 is parallel to the center of the chuck tube 3. It is formed from the tip to the base.

In this way, the 1108 rows of grooves are distributed at equiangular positions on the inner periphery.

The boundary between the groove 11 and the inner periphery of the chuck tube 3 is left relatively sharp, and a linear biting part 12 is formed here, and a gripping part 13 is formed between the adjacent grooves 11. be.

Horizontal grooves 14, which are sufficiently shallower than the vertical grooves 11, are arranged in a row on the inner circumferential surface of the gripping portion 13 so as to be orthogonal to the axial direction.

Therefore, in the above configuration, when the tool 10 is inserted and the tightening operation cylinder 5 is tightened, the chuck cylinder 3 is contracted by the roller 9, and in this case, the chuck cylinder 3 has the vertical grooves 11 on the inner circumference.
・Since it is recessed, the amount of elastic deformation caused by tightening is absorbed here and it bulges inward.

At the same time, the fragmented gripping part 13 tends to bite into the shank of the tool 10, and the chuck cylinder 3 as a whole contracts due to the presence of the vertical grooves 11, and is strong due to the high surface pressure due to the existence of the gripping part 13. This is a situation where it gets eaten into.

In the above case, if the gripping parts 13 are placed at equiangular positions, the entire circumference can be gripped evenly with equal force, and stable work can be performed.
Due to the presence of the gripping portion 13 and the fact that the entire chuck tube 3 has a thick inner shape, the axial runout of the tool 10 is reduced.

Particularly in this case, if the base of the chuck tube 3 is made thicker so that the tube 3 substantially protrudes from the slightly forward side, this deflection can be further reduced.

Furthermore, since the vertical groove 11 releases the local pushing action of the roller 9 through elastic deformation, the outer circumferential portion corresponding to the roller 9 tends to dent, and this causes the roller 9 to take a lock-like posture with respect to the chuck cylinder 3 side, and the chuck. Due to the rotational inertia, etc., it is possible to obtain a state in which it does not loosen at all.

Furthermore, when the tool 10 receives rotational torque as resistance, the biting portion 12 bites in conjunction with the recessed state, thereby making slip prevention even more precise.

Furthermore, the presence of the lateral grooves 14 makes it possible to remove foreign substances such as oil or iron powder attached around the tool 10 and to cut a long object into pieces. In particular, when the tool 10 is twisted, the lateral grooves 14 prevent the gripping portion 13 from being removed. Since it is an independent type in which the parts are cut into pieces, the stress is not concentrated only on the gripping part 13 at the tip due to this twisting, but is easily applied to the entire length, and the degree of wear and tear is reduced.

According to this invention, the tool can be gripped evenly and evenly as described above, and the gripping state is achieved by forcible biting due to high surface pressure, so the tool does not slip at all, and as described above, By setting each dimension, the runout of the tool can be reduced to a small or medium range, leading to high precision machining.

In particular, this invention has a major feature in that it has double rows of vertical and horizontal grooves, the vertical grooves are formed from semi-cylindrical or similar curved surfaces, and the horizontal grooves are shallower than the vertical grooves. It produces exceptional effects.

In other words, the chuck tube has a tapered outer periphery and tends to be thicker on the base side, so it has a characteristic that the base side is difficult to tighten and the tip end side is easy to tighten.

Therefore, the base side appears as a resistance part during chucking with respect to the distal end side, and the actual chuck operating force is mainly spent on this resistance part, and energy is concentrated due to its reduction and deformation.

For this reason, the tip opening side tends to be left as a part that does not receive enough tightening since it is easy to tighten.

Not only that, the chuck tube is subjected to strong compressive stress from the outer periphery, while the tool resists on the inner periphery, which tends to cause deformation strain on the mouth side in the axial direction, resulting in the mouth being slightly warped. .

In order to deal with this mouth condition, horizontal grooves are provided in addition to the vertical grooves.

First of all, using only vertical grooves improves the fit and is particularly effective in preventing slippage, but the problems in the axial direction mentioned above have not been improved at all. This makes it easier to tighten the base side of the chuck cylinder, and as a result, it has become possible to tighten the mouth to a sufficient extent, and the warping of the mouth is absorbed by the axial groove dividing action of the horizontal groove. As a result, the amount of warpage was significantly reduced.

However, if the horizontal grooves are made too deep, the base will become weak, and if the vertical grooves are made into square grooves, the parts that correspond to the grooves will be weak due to the shape of the grooves, and strong and uniform tightening will not be possible and impact torque will increase. On the other hand, for various reasons such as the disadvantage of weak hips, the horizontal grooves are made shallow to achieve the above effect and maintain strength in the hips, and the vertical grooves are semicircular or similar in shape to ensure uniform tightening. We devised a way to force the gripping part to bite strongly and provide resistance, and by adding the ejecting promotion effect of the lateral grooves to this, we were able to ensure strong and stable chucking as a whole.

The shape of the vertical groove 11 can be formed by a part smaller than a semicircle of a circle, or can be formed by a desired curved surface other than a circle. Undesirable in terms of sex or other aspects.

Further, the needle roller 9 may also be provided on the outer periphery of the operation cylinder 5, and in this case, a cylinder for holding it is provided protruding from the catch seat 2 to surround it.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of a chuck showing an example of this invention, FIG. 2 is a bottom view thereof, and FIG. 3 is an enlarged explanatory view of the chuck tube. 1...Chuck body, 3...Chuck tube, 5...Tightening operation tube, 9...Needle roller, 10... Tools, 11...
・Vertical groove.

Claims (1)

[Scope of utility model registration request] A chuck cylinder is provided on the tip side of the chuck body and has a tapered outer periphery that is continuous in the circumferential direction with an inner periphery in which a groove is formed. A tightening operation tube having a diameter of 100 mm is surrounded and rotatably equipped, and a group of needle rollers whose axes are inclined with respect to the generatrix of the tapered surface are provided between the inner and outer sides of the chuck tube and the tightening operation tube. In the loaded chuck, the grooves on the inner periphery of the chuck cylinder are arranged at equal intervals in the circumferential direction and their longitudinal direction is parallel to the axis of the chuck cylinder.
and lateral grooves 14 arranged in parallel in rows in the axial direction on the inner periphery excluding the vertical grooves 11.
1 has a semi-cylindrical cross section or a similar curved shape, and the horizontal grooves 14 are formed shallower than the vertical grooves 11.