JP3180173B2 - Holding tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holder for holding a cutting member such as a drill or a workpiece to be machined in a machine tool.

[0002]

2. Description of the Related Art In a conventional holder, a shank provided at one end of a main body for attachment to a main shaft of a machine tool has a tapered shape corresponding to the tapered hole of the main shaft, and the shank is formed into a tapered hole. On the other hand, by fitting the outer peripheral surface of the former and the inner peripheral surface of the latter so as to be in close contact with each other, it is possible to mount the main shaft in a state where the axis of the main shaft and the axis of the main body coincide with high accuracy.

[0003]

In this conventional holder, when the main spindle is rotated and processing is performed, when a large lateral force is applied to the main body, a bend is generated between the shank portion and the main body, and the main spindle is subjected to machining. On the other hand, there has been a problem that the main body oscillates and the machining accuracy is reduced.

In order to increase the strength against the lateral force and prevent the run-out of the center, when the shank portion is fitted exactly into the tapered hole of the main shaft, a flange provided around the main body is attached to the main shaft. Techniques have been devised for just abutting the end face, but for that purpose there has been a problem that the holder must be formed with extremely high machining accuracy. Therefore, in order to avoid the problem, a rubber plate is attached to the surface of the flange facing the end surface of the main shaft, and when the shank portion enters the tapered hole, the rubber plate first contacts the end surface of the main shaft. Attempts have been made to make the outer peripheral surface of the shank portion closely contact the inner peripheral surface of the tapered hole by compressing the rubber plate as the shank portion goes deeper (Japanese Patent Application No. 4-177370).

However, such a structure has a problem that the rubber plate is crushed within a short period of time if the attachment and detachment are repeatedly performed, and the desired effect of preventing the core from oscillating is lost.

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art, and can be mounted in a state in which the axis of the machine tool is properly aligned with the spindle, and the machining operation is performed in the mounted state. An object of the present invention is to provide a holder that can perform a center runout prevention function when performed, and that can exert those effects even in long-term repeated use.

[0007]

In order to achieve the above object, a holder according to the present invention is provided with a holder for holding an object to be held at one end in the axial direction of a main body, and at the other end, the main body is machined. A holder provided with a corresponding tapered shank portion adapted to be fitted into a tapered hole provided at an end of the main shaft in order to mount the main shaft of the machine so as to be aligned with the main shaft; A flange-shaped receiving portion is formed on the outer periphery so as to face the end surface of the main shaft, and an end surface on the shank portion side is located at a position closer to the shank portion than the receiving portion. An annular contact member serving as a contact surface for contacting the end surface of the main body is provided so as to be able to advance and retreat in the axial direction of the main body, and between the receiving portion and the contact member,
An elastic hydraulic chamber is provided for urging the contact member toward the shank portion to press the contact surface against the end surface of the spindle.

[0008]

When the shank portion is inserted into the tapered hole of the main shaft, first, the contact surface of the member comes into contact with the end surface of the hole edge of the main shaft. Further, when a force is applied to the shank portion in the direction of the depth of the tapered hole, the member abuts against the biasing force applied thereto while the abutment surface is in contact with the end surface, and the body is positioned on the side opposite to the shank portion. The shank moves slightly toward the above-mentioned depth while moving relatively to the inner surface of the tapered hole. In this state, the core between the main shaft and the holder coincides with high accuracy. In addition, even if a large lateral force is applied to the main body of the holder, the member is in a state of a stick, thereby preventing the main body from bending with respect to the shank portion and the holder from swaying.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In FIG. 1, reference numerals 1 to 4 denote known structures in a machine tool, 1 is a frame, 2 is a rotatable main shaft, 3
Denotes a taper hole for mounting the holder, and 4 denotes a puller. Next, the holder 5 will be described in detail with reference to FIGS.
Reference numeral 6 denotes a main body of the holder, which is formed in a thickness having necessary and sufficient rigidity. Reference numeral 7 denotes a flange-shaped receiving portion that faces the end surface 2a of the main shaft 2. The mounting portion 7a for the later-described contact member is formed on the outer periphery of the main body 6 to have a slightly smaller diameter so as to have a flange shape. Here is an example. It may be formed in a flange shape projecting from the outer periphery of the main body 6. Reference numeral 8 denotes a fitting part of the transmission member formed on a part of the mounting part 7a. Reference numeral 9 denotes a holding portion for holding an object provided at one end of the main body 6, and a cutting tip as an example of the object to be held.
9a is fixedly held. The holding portion may be a cutting member such as a drill or a chuck for detachably holding a workpiece as a workpiece. Reference numeral 10 denotes a shank portion provided at the other end of the main body 6. The outer peripheral surface is formed integrally with the main body 6 in a tapered shape corresponding to the inner peripheral surface of the tapered hole 3.
Reference numeral 11 denotes a pull stud provided at the tip of the shank portion 10.

Next, reference numeral 12 denotes a contact member provided on the outer periphery of the main body 6,
An axis 6a of the main body 6 is formed in an annular shape along the mounting portion 7a.
It is provided to be able to move forward and backward in the direction. Reference numeral 13 denotes a fitting portion provided on a part of the outer periphery of the corresponding member 12, and a driving piece provided on the main shaft 2.
This is the part for fitting 2c. Reference numeral 14 denotes an abutment surface with respect to the end surface 2a of the main shaft 2, which is a surface which is divided into a plurality of parts in the circumferential direction for the presence of various members 25, 26, 27 described later, but may be formed as a continuous surface. 15 is a fitting portion formed on the inner peripheral surface of the member,
Reference numeral 16 denotes a transmission member for transmitting a rotational power from the member 12 to the main body 6. Reference numeral 18 denotes an elastic hydraulic chamber formed between the receiving portion 7 of the main body 6 and the contact member 12, and an outer peripheral surface of the mounting portion 7a and the receiving portion 7a.
A receiving surface 7b facing the shank portion 10, a pressure receiving surface 12b facing the receiving surface 7b in the member 12, an outer peripheral wall 19 integrally formed with the member 12, and an O-ring 2 for preventing oil leakage.
An example is shown having an internal space surrounded by 1, 22 and is filled with oil 20. When the oil 20 is pressurized by the member 12 being moved to the receiving portion 7 side, the elastic hydraulic chamber 18 is elastically deformed, for example, by the O-rings 21 and 22 being pressed and deformed by the oil 20. Is generated. The elasticity may be generated by partially deforming the member 12. The oil in the hydraulic chamber 18 is initially filled with a relatively large amount, and the member 12 is moved to the receiving portion 7 in a predetermined axis line as shown in FIG. The oil drain hole 26 is closed with a stopper 27. 23 is an elastic hydraulic chamber for adjusting the oil amount of the elastic hydraulic chamber 18.
A cylinder provided in communication with 18 has a piston 24 for adjusting the amount of oil, which is movable forward and backward. The piston 24 is for adjusting the amount of the oil 20 in the elastic hydraulic chamber 18 so that when the contact surface 14 is pressed against the end face 2a as shown in FIG. The adjustment is performed by operating the push screw 25 in a state where the holder 5 is not mounted on the main shaft 2. The cylinder 23 may be provided in the main body 6 so as to communicate with the hydraulic chamber 18. Reference numeral 28 denotes a retaining ring for the member 12.

[0011] In the above structure, the holder 5 is attached to the main shaft 2.
When mounting, as is well known, the shank part 10
As shown in Fig. 5 and pull stud with puller 4.
Pull the shank part 10 through 11. Then, first, the contact surface 14 of the contact member 12 contacts the end surface 2a of the main shaft 2 as shown in FIG.
At this time, the inner peripheral surface 3a of the tapered hole 3 and the outer peripheral surface of the shank portion 10
A slight gap remains between the gap 10a. When the shank portion 10 further enters the tapered hole 3 by a small dimension, the outer peripheral surface 10a comes into close contact with the inner peripheral surface 3a as shown in FIG.
And the axis 6a of the main body 6 coincide with each other. In this case, the contact member 12 slightly moves toward the receiving portion 7 with respect to the main body 6 in the contact state, and the oil 20 in the elastic hydraulic chamber 18 is pressurized to increase the pressure. Is brought into pressure contact with the end face 2a with a large pressure. Note that the distance between the receiving surface 7b and the pressure receiving surface 12b may be any size as long as it allows a slight movement of the contact member 12 as described above.

When the main shaft 2 is rotated in the above-mentioned mounted state, the holder 5 is integrally rotated. In this case, the rotational power of the main shaft 2 is transmitted from the driving piece 2c to the contact member 12 via the fitting portion 13, and further transmitted to the main body 6 via the transmission member 16. With the rotation of the holder 5, the workpiece W is cut by the tip 9a. In the case of the cutting, even if a large lateral force is applied to the main body 6 of the holder 5 to bend the shank portion 10 with the main body 6 of the holder 5 due to the cutting resistance applied to the tip 9a, the contact surface 14 is kept on the outer peripheral side of the shank portion 10 for the time being. At the end face 2a,
The main body 6 is provided with a large proof stress against the lateral force, and the bend is prevented. As a result, the centering of the holder main body 6 with respect to the main shaft 2 is prevented.

For example, when a force is applied to tilt the axis 6a of the main body 6 in the direction of arrow 31 in FIG.
The oil 20 on the side indicated by reference numeral 18a has a stronger compressive force, and the oil 20 on the side indicated by reference numeral 18b
20 is less compressive. Then, the pressure of the receiving surface 7b in the elastic hydraulic chamber 18a increases, and the pressure of the receiving surface 7b in the elastic hydraulic chamber 18b decreases. As a result, the main body 6 receives a force in the direction opposite to the direction of the arrow 31, and the bend is prevented. In the above case, the holding tool 5 is in a rotating state, and the force for bend is applied by the number of chips 9a per unit time per rotation number (for example, several hundred to several thousand RPM) of the main shaft 2. Is performed at such a high speed that the number of times is multiplied by. Therefore, even if the elastic hydraulic chamber 18a and the elastic hydraulic chamber 18b are continuous, pressure cannot be transmitted between them (for example, due to the viscosity of the oil 20). Is applied in the opposite direction. In order to perform such an operation, it is preferable to use a higher viscosity oil as the rotation speed of the main shaft per unit time is smaller. As a result of the bend prevention as described above, the axis 6a of the main body 6 is kept aligned with the axis 2b of the main shaft 2,
Workpieces can be cut with high precision.

Next, if there is a margin in the movable size of the contact member 12 with respect to the axial direction of the main body 6, the right angle accuracy of the end face 2a of the main shaft 2 is low, or as shown in FIG. Even if the holding member 5 is attached to the main shaft 2 and the holding member 5 is inclined, even if the holding member 5 is attached to the main shaft 2, even if the holding member 5 is inclined, the oil 20 is kept in the elastic hydraulic chamber.
Since the pressure is constant throughout 18, the above-described bend prevention action is performed without any difference.

FIG. 8 shows another embodiment of the present invention, in which a metal spring is provided between the receiving portion 7e and the contact member 12e as a means for applying a biasing force. The metal spring is exemplified by a disc spring 33, which is interposed between the receiving surface 7be and the pressure receiving surface 12be. In addition, portions that are considered to have the same or equivalent configuration as those in the previous figure in terms of function are denoted by the same reference numerals as in the previous figure with the letter e, and redundant description is omitted.

[0016]

As described above, according to the present invention, when the holder 5 is attached to the main shaft 2 of the machine tool, when the shank 10 is inserted into the tapered hole 3 of the main shaft 2, first, the contact member 12 14
Abuts against the end surface 2a of the hole edge of the main shaft 2, and further applies a force to the shank portion 10 in the depth direction of the tapered hole 3, whereby the end surface
While the contact surface 14 is in contact with the contact surface 2a, the contact member 12 moves relative to the main body 6 on the side opposite to the shank portion 10 against the biasing force applied thereto, while the shank portion 10 It moves slightly in the direction, and its outer peripheral surface 10a has a feature of being in close contact with the inner peripheral surface 3a of the tapered hole 3. As a result, the alignment of the core between the main shaft 2 and the holder 5 is performed with high accuracy,
This has the effect of improving the processing accuracy of the workpiece,
Even if a large lateral force is applied during the working operation, there is an effect that the center run-out of the tool holder 5 with respect to the main shaft 2 is prevented and high-precision working can be performed.

Further, the urging of the contact member 12 is performed by the elastic hydraulic chamber.
18 or a metal spring 33 having a highly durable configuration, it is possible to maintain the function of urging the member 12 even if the holder 5 is repeatedly attached to and detached from the main shaft 2. There is an advantage that the above-mentioned core runout preventing effect can be surely exerted over the use of.

[Brief description of the drawings]

FIG. 1 is a side view showing a use state.

FIG. 2 is an enlarged sectional view of a main part in FIG.

FIG. 3 is a view showing a state where the holder is viewed from a shank portion side.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2;

FIG. 5 is a view similar to FIG. 2, showing a state before mounting on a spindle.

FIG. 6 is a view similar to FIG. 2, showing a state in which the device is being mounted on a main shaft.

FIG. 7 is an enlarged sectional view of a main part showing an example of a different use state.

FIG. 8 is an enlarged sectional view of a main part showing a different embodiment.

[Explanation of symbols]

 6 body 7 receiving part 9 holding part 10 shank part 12 applicable member 18 elastic hydraulic chamber 33 metal spring

Claims (2)

(57) [Claims] At least one end of the main body in the axial direction is provided with a holding portion for holding an object to be held, and the other end is provided with an end of the main shaft for mounting the main body so that the main body is aligned with the main shaft of the machine tool. In a holder provided with a corresponding tapered shank portion adapted to be fitted in a tapered hole provided in a portion, a flange-shaped receiving portion is formed on an outer periphery of the main body so as to face an end surface of the main shaft. At the same time, at the position closer to the shank portion than the receiving portion, an annular contact member whose end surface on the shank portion side is an abutting surface for contacting the end surface of the peripheral edge of the tapered hole in the main shaft, An elastic hydraulic pressure is provided between the receiving portion and the abutting member so that the abutting member is biased toward the shank portion so that the abutting surface is pressed against the end surface of the main shaft between the receiving portion and the abutting member. A holder provided with a chamber. 2. A main body is provided with a holding portion for holding an object at one axial end thereof, and the other end of the main shaft is provided at the other end thereof so that the main body can be mounted in such a manner that its axis coincides with the main shaft of the machine tool. In a holder provided with a corresponding tapered shank portion adapted to be fitted in a tapered hole provided in a portion, a flange-shaped receiving portion is formed on an outer periphery of the main body so as to face an end surface of the main shaft. At the same time, at the position closer to the shank portion than the receiving portion, an annular contact member whose end surface on the shank portion side is an abutting surface for contacting the end surface of the peripheral edge of the tapered hole in the main shaft, A metal spring that is provided so as to be able to advance and retreat in the axial direction of the main body, and between the receiving portion and the member, biases the member toward the shank portion and presses the contact surface against the end surface of the main shaft. A holder comprising: