JPH0740007U - Hydro chuck - Google Patents

Abstract

(57) [Summary] [Structure] The void 2 provided inside the chuck body 20.
2 is provided in the vicinity of the tip of the chuck cylinder 21 and extends in the radial direction near the tip, and the tip cavity 25 is provided on the radius line of the chuck cylinder 21 on the end face side of the tip of the chuck cylinder 21 through the cavity 25. Thinned portion 26 at the tip portion that is deformed and extends longer than the distance L
Forming an incompressible fluid 24 enclosed in the cavities 22 and 25
The pressure was applied to the mouth of the chuck cylinder 21. [Effect] Sufficient chucking force can be exerted even at the mouth of the chuck cylinder, and the chuck length can be made longer than in the conventional case.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chuck for mounting a chucked body such as a cutting tool on a spindle of a machine tool. More specifically, a compressible fluid is enclosed inside the wall thickness of a chuck body of a chuck body that constitutes the chuck. The present invention relates to a hydro chuck in which the inner peripheral surface side of the chuck cylinder is expanded by the external pressure received by the compressible fluid, and thereby the chucked body fitted in the cylinder hole of the chuck cylinder is chucked.

[0002]

[Prior art]

 FIGS. 3 and 4 show a screw operating type prior art of this type of hydro chuck, in which a chuck cylinder 2 is projectingly provided on a tip side of a chuck body 1 and fitted to a spindle of a machine tool at a rear end side thereof. The shank 3 is projected, and the manipulator holding groove 4 is formed in the middle part.

A cavity 5 is formed inside the wall thickness of the chuck cylinder 1 and over the entire inner peripheral surface side thereof, and in the axial direction from the back end side of the chuck cylinder 1 to the tip end thereof. The thin portion 6 is formed on the entire circumference of the circumferential surface. A screw hole 7 is formed in the chuck body 1 from the outer peripheral side thereof in the radial direction, and the tip end side of the screw hole 7 is formed into a straight hole 7a. The straight hole 7a communicates with the void 5. There is.

The tip end side of the screw rod 8 screwed into the screw hole 7 is also formed straight, and an oil-tight ring 9 such as an O-ring is attached to the outer peripheral surface of the straight portion 8 a to attach the screw rod 8 to the screw hole. The screw hole 7 and the cavity 5 communicating with the screw hole 7 are formed in a hermetically sealed state by being screwed in an oil-tight manner into the screw hole 7, and an incompressible fluid 10 such as water or oil is enclosed in the screw hole 7.

Therefore, as shown in FIG. 4, by operating the screwing amount of the screw rod 8 with respect to the screw hole 7 by using an appropriate wrench T, the volume of the screw hole 7 and the space 5 communicating with the screw hole 7 becomes larger. When the volume decreases, pressure is applied to the incompressible fluid 10 enclosed in the screw hole 7 and the space 5, and the thin portion 6 on the inner peripheral surface side of the chuck cylinder 1 is passed through the incompressible fluid 10. As shown by the arrow in FIG. 3, a uniform pressure is applied to the entire area of the cylinder as shown by the arrow in FIG. 3, whereby the thin portion 6 expands toward the cylinder hole 1a as shown by the chain double-dashed line, and is fitted into the cylinder hole 1a. The chucked body W such as a cutting tool is strongly chucked by the chuck cylinder 1 due to the expansion of the thin portion 6.

[0006]

[Problems to be solved by the device]

 As described above, on the inner peripheral surface side of the chuck cylinder 1, the void 5 is formed up to the vicinity of the tip end thereof, and the non-compressible fluid 10 enclosed in the void 5 substantially covers the entire inner peripheral surface. Expands as shown by the chain double-dashed line in FIG. 3 and exerts a strong chucking force. However, as shown in FIG. 3, it is possible to form the cavity 5 up to the vicinity of the tip of the chuck cylinder 1. However, since the chuck cylinder 1 receives a strong pressure of the incompressible fluid 10, the tip 1b of the chuck cylinder 1 must be left with a certain thickness, as shown in FIG. As shown in the drawing, the portion of the thick portion 1b having the width L1 naturally does not exert the expansion action, so that there is a disadvantage that the chucking force does not act on the mouth portion 1b of the chuck cylinder 1, which is the reason why the chucking is not performed. The chuck length L2 of cylinder 1 is reduced by L1. Chat by cylinder 1 King are the example cutting tool W (FIG. 4) has been a cause of occurrence of such phenomenon chatter in its use developing.

The present invention solves the above problems of the conventional hydrochuck, and exerts sufficient chucking force even at the mouth portion of the chuck cylinder, thereby making the chuck length longer. To do.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the invention according to claim 1, a chuck 22 is provided by providing a void 22 inside the thickness of a chuck cylinder 21 of a chuck body 20 as indicated by the reference numeral of the embodiment. A thin portion 23 is formed on the inner peripheral surface side of the cylinder 21, an incompressible fluid 24 such as water or oil is enclosed in the void 22, and the thin portion of the chuck cylinder 21 is caused by an external pressure applied to the incompressible fluid 24. In a hydro chuck in which the chucked body W fitted into the chuck cylinder 20 is chucked by expanding 23, the tip of the chuck cylinder 21 communicates with the void 22 provided inside the chuck body 20. Is provided with a tip end cavity 25 extending in the radial direction in the vicinity of the end portion, and the tip end is deformed and extends longer than the distance L on the radial line of the chuck cylinder 21 toward the tip end face side of the chuck cylinder 21 through the tip cavity 25. Thin part 2 It is intended to employ the formed comprising configure.

Further, in the invention according to claim 2, the tip thinned portion 26 which is deformed and extends to the tip end face side of the chuck cylinder 21 longer than the distance L on the radial line of the chuck cylinder 21 is on the radial line. The structure according to claim 1 is formed so as to be curved so as to deviate from it.

Further, in the invention according to claim 3, the tip thinned portion 26 which is deformed and extends to the tip end face side of the chuck cylinder 21 longer than the distance L on the radial line of the chuck cylinder 21 is on the radial line. The configuration according to claim 1 is formed so as to be inclined so as to deviate from it.

[0011]

[Action]

 According to the first aspect of the invention, as shown in FIG. 1, a tip cavity 25 is formed at the tip of the chuck cylinder 21 in the radial direction to the vicinity of the outer peripheral side, and the chuck is provided through the cavity 25. Since the thin portion 26 formed on the end face side of the tip end portion of the cylinder 21 is deformed so as to be longer than the distance L on the radial line of the chuck cylinder 21, the inner peripheral surface side space 22 and the front end space 25 are formed. Due to the external pressure applied to the non-compressible fluid 24 enclosed over the end, the tip thin portion 26 elastically deforms from its deformed state so as to extend in the radial direction, and the elastic deformation of the thin portion 26 causes the tip end of the chuck cylinder 21. The mouth portion 27, which is the inner peripheral surface of the portion, expands toward the cylinder hole 21a side, which allows the mouth portion 27 of the chuck cylinder 21 to exert a sufficient chucking force, and the chuck length is longer than that of the conventional case. Can be lengthened That.

According to the second aspect of the present invention, as shown in FIG. 2, the thin tip portion extends toward the end surface of the chuck cylinder 21 by deforming and extending longer than the distance L on the radial line of the chuck cylinder 21. Since 26 is formed by bending so as to deviate from the radial line, the tip end thinning is caused by the external pressure received by the incompressible fluid 24 enclosed between the inner peripheral surface side void 22 and the tip end void 25. The portion 26 is elastically deformed from the curved deformation state so as to linearly extend in the radial direction, and the elastic deformation of the thin portion 26 causes the mouth portion 27, which is the inner peripheral surface of the front end portion of the chuck cylinder 21, to expand toward the cylinder hole 21a. It will be.

Further, in the invention according to claim 3, the tip thin portion 26, which is deformed and extends longer than the distance L on the radial line of the chuck cylinder 21 on the tip end face side of the chuck cylinder 21, extends on the radial line. Since it is formed so as to be deviated from the inner peripheral surface side cavity 22 and the tip end cavity 25, the tip thin portion 26 is inclined due to the external pressure applied to the incompressible fluid 24 enclosed between the cavity 22 and the tip cavity 25. Elastically deforms so as to come closer to the radial line, and the elastic deformation of the thin portion 26 causes the mouth portion 27, which is the inner peripheral surface of the tip end portion of the chuck cylinder 21, to expand toward the cylinder hole 21a.

[0014]

【Example】

 FIG. 1 shows an embodiment of the present invention. As in the conventional case, a chuck cylinder 21 is projectingly provided on the front end side of a chuck body 20 and fitted to a spindle of a machine tool on the rear end side thereof. A shank is provided so as to project, and a manipulator holding groove 28 is formed in the middle portion.

A hollow space 22 is formed inside the wall thickness of the chuck cylinder 21 and over the entire circumference on the inner peripheral surface side thereof, and in the axial direction from the rear end side to the tip end of the chuck cylinder 21. A thin portion 23 is formed on the entire circumference of the circumferential surface. In this embodiment, the front end side 23a and the rear end side 23b of the thin portion 23 are formed thin so as to be easily deformed, but the central portion 23c is formed thicker than both end sides. As a result, the strength of the thin portion 23 is increased and a stable chucking force is exerted.

At the tip of the chuck cylinder 21, a tip cavity 25 is formed in communication with the inner circumferential surface side cavity 22 in the outer peripheral direction, that is, at a right angle to the radial direction. A tip thin portion 26 is formed on the end face side via a tip void 25. The thin walled portion 26 is deformed and extends longer than the distance L on the radial line of the chuck cylinder 21. Specifically, in the embodiment shown in FIG. 1, it is formed so as to be curved inward. There is.

As shown in FIG. 4 of the prior art, although not shown, the chuck body 20 is provided with a screw hole 7 in the radial direction from the outer peripheral side thereof, and the tip end side of the screw hole 7 is a straight hole. 7a, and the straight hole 7a communicates with the void 22 on the inner peripheral surface side.

The tip end side of the screw rod 8 screwed into the screw hole 7 is also formed straight, and an oil-tight ring 9 such as an O ring is attached to the outer peripheral surface of the straight portion 8a so that the screw rod 8 is screwed into the screw hole. 7 is screwed in an oil-tight manner so that the screw hole 7 and the inner peripheral surface side cavity 22 and the tip thinned portion 26 communicating with the screw hole 7 are formed in a sealed state. A compressible fluid 24 is enclosed.

Therefore, by manipulating the screwing amount of the screw rod 8 into the screw hole 7, the volumes of the screw hole 7 and the cavities 22 and 25 communicating with the screw hole 7 are changed, and the volume is reduced, whereby the screw hole 24 A pressure is applied to the incompressible fluid 24 that is enclosed between the inner wall 22 and the cavities 22 and 27, and the thin wall portion 23 and the thin wall portion 26 on the inner peripheral surface side of the chuck cylinder 21 are exposed to Pascal through the incompressible fluid 24. According to the principle, a uniform pressure is applied, which causes the thin portion 23 on the inner peripheral surface side to expand toward the cylinder hole 21a as shown by the chain double-dashed line in Fig. 1, and the cutting tool fitted into the cylinder hole 21a. The object W to be chucked is strongly chucked to the chuck cylinder 1 by the expansion of the thin portion 6.

In particular, when the pressure of the incompressible fluid 24 is applied from the tip cavity 25 to the tip thin wall portion 26 opposite thereto, the thick wall portion 26 has a thickness as shown by a chain double-dashed line in FIG. Elastically deforms from the curved state so as to linearly extend in the radial direction, whereby the mouth portion 27 of the chuck cylinder 21 communicating with the thick portion 26 is caused by the bulging action of the thick portion 26 as shown by the arrow. The chucked body W that expands toward the cylindrical hole 21a side and is fitted into the cylindrical hole 21a of the chuck cylinder 21 can be strongly chucked even at the mouth portion 27, and the inner peripheral surface of the chuck cylinder 21 can be chucked. Since the chuck length L3 of the tool is much longer than the conventional one, it has strong durability against the cutting force applied to the cutting tool W during the cutting work by the cutting tool W, and the chattering phenomenon of the cutting tool W etc. Wipe away as much as possible It can withstand use even in heavy cutting such as milling chucks.

FIG. 2 shows another embodiment of the present invention. In this embodiment, it is formed in the radial direction of the tip portion of the chuck cylinder 21 so as to communicate with the space 22 on the inner peripheral surface side. The tip end cavity 25 is provided so as to be inclined toward the tip end surface side toward the outer peripheral side, whereby the tip end thin portion 26 formed on the tip end surface side of the chuck cylinder 21 also faces the outer peripheral side. In accordance with this, the tip thin portion 26 is provided so as to be inclined toward the tip surface side, so that the tip thin portion 26 extends so as to be longer than the distance L on the radial line of the chuck cylinder 21.

With this configuration as well, the pressure of the incompressible fluid 24 is applied from the tip cavity 25 to the tip thin wall portion 26 facing the hollow portion 25, so that the thin wall portion 26 is formed by the two-dot chain line in FIG. As shown in FIG. 7, the slanted state is elastically deformed so as to approach the radial line, whereby the mouth portion 27 of the chuck cylinder 21 integrated with the thick portion 26 is indicated by an arrow by the thrusting action of the thin portion 26. It is possible to strongly chuck the body W to be chucked, which expands to the side of the cylindrical hole 21a and is fitted into the cylindrical hole 21a of the chuck cylinder 21 even at the mouth portion 27.

In the above embodiment, a screw hole communicating with the cavity 22 as an external load means for the incompressible fluid 24 enclosed in the cavity 22, 25 of the chuck cylinder 21 and a screw rod screwed into the cavity are provided. Depending on the screw operating means, the present invention is not limited to this. For example, a chuck such as a needle chuck or collet chuck that reduces the diameter of the chuck cylinder by the tightening action of a tightening nut that fits on the outer peripheral side of the chuck cylinder. It can also be applied to the type that applies pressure to the incompressible fluid sealed in the void by the external pressure from the outer peripheral side of the cylinder.

[0024]

【effect】

 According to the first aspect of the present invention, the thin portion at the tip portion extends in the radial direction from the deformed state thereof due to the external pressure applied to the incompressible fluid enclosed in the cavity at the inner peripheral surface side and the cavity at the tip portion. The elastic deformation of the thin part causes the mouth part, which is the inner peripheral surface of the front end part of the chuck cylinder, to expand toward the cylinder hole side, and as a result, a sufficient chucking force is exerted at the mouth part of the chuck cylinder. It is possible to make the chuck length much longer than the conventional one.

Increasing the tightening force at the mouth of the chuck cylinder as described above is particularly effective for chucking a cutting tool having a small diameter and a short axial length. That is, with a cutting tool having a short axial length, the shank cannot be inserted deep inside the chuck cylinder, and the chuck will be chucked at a position closer to the tip of the chuck cylinder. If the chucking force of the part is strong, the cutting tool can be strongly chucked even when it is chucked near the tip inside the chuck cylinder, and accurate cutting work can be performed.

According to the second aspect of the present invention, since the thin wall portion of the tip end portion of the chuck cylinder is formed so as to be curved while deviating from the radial line of the chuck barrel, the front end space facing the thin wall portion of the tip end portion is bent. It can be elastically deformed in the radial direction favorably by the load of the incompressible fluid, and can exert a strong tensioning action on the mouth of the chuck barrel, which is why the chucked body at the mouth of the chuck barrel is chucked. It can significantly improve the chucking power for

According to the third aspect of the present invention, since the thin wall portion of the tip portion of the chuck cylinder is formed so as to be inclined so as not to be aligned with the radial line thereof, there is a space on the inner peripheral surface side and a space on the tip portion. Due to the external pressure applied to the incompressible fluid filled over the entire area, the thin-walled portion at the tip end elastically deforms from its tilted state toward the radial line, and the elastic deformation of this thin-walled portion causes the chuck cylinder to move. The mouth part, which is the inner peripheral surface of the tip part, expands toward the cylinder hole side, which can significantly improve the chucking force for the chucked body at the mouth part of the chuck cylinder, and also the chuck cylinder Since it is only necessary to form the tip end in an inclined shape, manufacturing is relatively easy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is a cross-sectional view showing a conventional technique.

FIG. 4 is a diagram illustrating a usage state of this type of hydro chuck.

[Explanation of symbols]

 20 Chuck Main Body 21 Chuck Cylinder 22 Space 23 Thin Wall 24 Incompressible Fluid 25 Tip Space 26 Tip Thin Wall

Claims (3)

[Scope of utility model registration request] 1. A thin portion is formed on the inner peripheral surface side of the chuck cylinder by providing a cavity inside the thickness of the chuck cylinder of the chuck body.
A non-compressible fluid such as water or oil is sealed in the void, and the thin portion of the chuck cylinder is expanded by the external pressure received by the non-compressible fluid, thereby chucking the chucked body fitted to the chuck cylinder. In the hydro chuck, a tip cavity is provided, which communicates with a cavity provided inside the chuck body and extends in the radial direction near the tip of the chuck barrel, and the tip of the chuck barrel is inserted through the cavity. A hydro chuck in which a thin-walled tip portion is formed on the end face side so as to deform and extend longer than the radial distance of the chuck cylinder. 2. The tip thin portion, which extends on the end surface side of the tip end of the chuck cylinder by being deformed longer than the radial distance of the chuck barrel, is formed by bending so as to deviate from the radial line. Hydro chuck. 3. The tip thin portion, which is deformed and extends longer than the distance on the radial line of the chuck cylinder on the tip end face side of the chuck cylinder, is formed to be inclined so as to deviate from the radial line. Hydro chuck.