JPH0938837A - Holding tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly insert a holding tool into a main shaft by providing hollow space for deflecting a contact surface so as to reduce a diameter thereof and putting it into contact with the end in the state that an inserting part is press titled into the tapered hole of the main shaft. SOLUTION: A contact surface 24 is formed in a gradient larger than the gradient of an inner peripheral surface 3 and a contact surface 31 is formed in a gradient smaller than the gradient of an inner peripheral surface 3. The inner peripheral surfaces 25, 32 of joint parts 23, 30 are formed a little larger than the outer peripheral surfaces 26, 33 of a base 12 corresponding to them such that hollow spaces 27, 34 are formed in the contact surfaces 24, 31 to reduce the diameters of the contact surfaces. Since the contact surfaces 24, 31 of the joint parts 23, 30 are in press contact with the inner peripheral surface of a tapered hole 2, a contact surface 11 of a holding tool 6 is in contact with the end 4 of a main shaft 1 in a state in which the holding tool is inserted into a main shaft, whereby the axis of the holding tool 6 correctly agrees with the axis of the main shaft 1.

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 tool such as a drill or an end mill for machining, and more particularly to a structure of a mounting portion of the holder to a machine tool.

[0002]

2. Description of the Related Art The following is known as a holder of this type. That is, the insertion part for inserting into the taper hole provided in the main shaft of the machine tool is continuously provided at the other end of the main body having the tool mounting part at one end. The outer peripheral surface of the insertion portion is formed in a corresponding tapered shape so as to contact the inner peripheral surface of the tapered hole. An elastic member is provided around one end of the main body around the continuous portion of the insertion portion so as to be in contact with the end face of the main shaft, and the end face is sandwiched between the end face and the corresponding face. Is provided (for example, JP-A-5-3
(See JP 37769).

In such a structure, when the insertion portion is inserted into the tapered hole, the elastic body comes into contact with the end surface of the main shaft, and when the insertion portion is further advanced toward the deep portion of the tapered hole,
The outer peripheral surface of the insertion portion comes into contact with the inner peripheral surface of the tapered hole to firmly join the two. As a result, the holder is attached to the main shaft with a high degree of accuracy in matching the axial center. Further, when the outer peripheral surface of the insertion portion is firmly joined to the inner peripheral surface of the tapered hole, the elastic body is compressed with a large force between the contact surface and the end surface. As a result, the holder is more resistant to the lateral force applied thereto, and when the cutting operation is performed by rotating the main shaft, the runout of the holder can be prevented.

In order to further improve the core runout prevention effect, when the outer peripheral surface of the insertion portion is firmly joined to the inner peripheral surface of the tapered hole, the contact surface directly contacts the end surface of the spindle. Was thought. By doing so, since the outer peripheral surface of the insertion portion is firmly joined to the inner peripheral surface of the tapered hole, the contact surface is also firmly joined to the end surface, so that the above-described runout preventing effect can be extremely improved.

[0005]

However, since the spindles of the above-mentioned machine tools are manufactured under the control of various machine tool makers, and there are slight differences in the dimensions of the taper hole and the end face, the spindles of a particular manufacturer. Even if both the outer peripheral surface and the abutting surface of the insertion portion come into contact with each other as described above when mounted to, a gap is created on either the outer peripheral surface or the abutting surface when it is mounted on the spindle of another company. There was a problem. Furthermore, when wear occurs on the outer peripheral surface or the current surface due to repeated attachment / detachment with respect to the main shaft of the machine tool during use, one of them will not contact its opponent,
There was also a problem that the life was relatively short and limited.

The holder of the present invention is provided to solve the above-mentioned problems (technical problems) of the prior art. The first purpose is to enable the holder to be attached to the main shaft with high accuracy in matching the axes. The second purpose is
By allowing the immediate surface of the holder to directly contact the end surface of the spindle of the machine tool, the proof stress against the lateral force applied to the holder is extremely increased, and when performing the cutting work in the state of being attached to the spindle, It is to be able to exert the core runout prevention effect. A third object is to allow the machine tool to be mounted in a state in which the large effect of preventing runout is exhibited even if there is a difference in the size of the taper hole or the end surface of the machine tool spindle. A fourth object is to enable the use of a long life by being mounted in such a state that the above large runout prevention effect is exerted even if some wear occurs due to repeated attachment / detachment to / from the spindle. Is to Other objects and advantages will be more readily apparent from the drawings and the following description associated therewith.

[0007]

In order to achieve the above object, a holder according to the present invention has a taper hole provided in a spindle of a machine tool at the other end of a main body having a tool mounting portion at one end. The insertion part of the tapered shape for inserting into the taper hole is provided around the continuous part of the insertion part at the other end of the main body in the state where the insertion part is inserted into the tapered hole. A retainer having a contact surface for contacting an end surface, and the insertion portion having an abutment surface for contacting an inner peripheral surface of the taper hole on an outer peripheral surface, in the insertion portion. In order to bring the contact surface into contact with the end surface by bending the contact surface so as to reduce the diameter of the contact surface inside the contact hole while the insertion portion is press-fitted into the tapered hole. It has a hollow part.

[0008]

When the holder is attached to the main shaft, when the insertion portion is inserted into the tapered hole, the contact surface of the insertion portion comes into contact with the inner peripheral surface of the tapered hole. When the insertion portion is further press-fitted in the deep direction of the taper hole, the contact surface is bent by the inner peripheral surface of the taper hole so that its diameter is reduced and press-contacts with the inner peripheral surface of the taper hole. The abutment directly contacts the end face of the spindle. The contact of the contact surface with the inner peripheral surface of the tapered hole makes the axis of the holder coincide with the main shaft. Further, the abutting of the end face against the end face increases the proof stress of the holding tool against the lateral force.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 3, reference numerals 1 to 5 show well-known structures in a machine tool, 1 is a spindle, 2 is a tapered hole for attaching a holder provided at an end of the spindle, and 3 is an inner peripheral surface thereof. , Tapered. The gradient of the inner peripheral surface 3 is, for example, 7/2.
There are 4 gradients. Reference numeral 4 denotes an end surface of the main shaft 1, and 5 denotes a pulling tool for attaching the holding tool. Next, 6 shows a holder. Reference numeral 7 denotes a main body of the holder, which has a groove 8 on its outer peripheral surface for receiving a grip by a tool changer, and a fitting for fitting a driving piece on the machine tool side as shown in FIG. The unit 9 is provided. A tool mounting portion for detachably mounting a cutting tool such as a drill or an end mill is provided at one end of the main body 7 (the right end not shown in the drawing). The tool mounting portion may be a mounting portion to which a cutting tip is directly mounted, in addition to the above-described detachable mounting portion.

Next, reference numeral 10 denotes an insertion portion connected to the other end 7a of the main body 7, which is a portion for being inserted into the taper hole 2 to fix the holder 6 to the spindle 1. It is formed in a tapered shape for inserting. 11 is the above insertion part
This is a surface for contacting the end face 4 with the taper 10 inserted in the tapered hole 2, and is provided around the connecting portion 7a of the inserting portion at the other end of the main body 7 as shown in the drawing. Above insertion part
In order to make it easy to form a structure having hollow portions 27 and 34 as described later, in this example, a base portion 12 formed integrally with the main body 7 and a sleeve provided on the outer periphery thereof are provided. It consists of 13 and. Reference numeral 14 denotes a mounting portion for mounting the sleeve 13 on the base portion 12, the outer peripheral surface of which is formed in a straight cylindrical shape. 15 is sleeve 13
A disconnection portion 16 for positioning, and a retaining ring 16 for preventing the sleeve from coming off are fitted in a groove provided around the outer peripheral surface of the base portion 12. 17
Is a collar interposed between the retaining ring 16 and the sleeve 13 to prevent the end face of the sleeve 13 from being scratched, and 18 is a well-known pull stud for receiving the pulling operation by the pulling tool 5, and the base 12
It is screwed into the mounting hole of.

Next, the sleeve 13 will be described. 20
Shows the connecting portion to the base portion 12, and in order to improve the accuracy of alignment of the shaft center of the base portion 12 and the sleeve 13 when assembled to the mounting portion 14, it is connected to the mounting portion 14 by press fitting. , 21 are inner peripheral surfaces for joining to the mounting portion 14. Reference numeral 22 denotes the outer peripheral surface of the connecting portion 20, and the tapered hole 2
In order to ensure that the outer peripheral surface of the joint portion described below can be bonded to the inner peripheral surface 3, the relief portion is formed so as not to contact the inner peripheral surface 3. The outer peripheral surface 22 can be used as a holding portion when the sleeve 13 is cut during manufacturing. Reference numerals 23 and 30 denote joint portions provided on one end side and the other end side of the connecting portion 20, respectively, for joining the inner peripheral surface 3 of the tapered hole 2 when the holder 6 is attached to the main shaft 1. is there. Outer peripheral surfaces 24, 31 of these joints 23, 30
Is an abutment surface for making pressure contact with the inner peripheral surface 3 of the tapered hole 2. These contact surfaces 24 and 31 are inserted into the insertion portion 10
When the contact surfaces 24 and 31 are pressed into the tapered hole 2 and compressed by the inner peripheral surface 3 of the tapered hole 2, the contact surfaces 24 and 31 are brought into contact with the inner peripheral surface 3 in the largest possible area. Therefore, the free ends of the joints 23 and 30 (the joint 20
The taper surface 3 is contacted from the side opposite to the connection part (). For that purpose, the contact surface 24 is formed with a slope larger than that of the inner peripheral surface 3, and the contact surface 31 is formed with a slope smaller than that. The inner peripheral surfaces 25, 32 of the two joints 23, 30 are hollow portions for allowing the diameter of the contact surfaces to be reduced inside the contact surfaces 24, 31 as shown in the figure. So that 27 and 34 are formed,
It is formed to be slightly larger than the outer peripheral surfaces 26 and 33 of the corresponding base portion 12.

Next, the mounting of the holder 6 having the above-mentioned structure on the main shaft 1 will be described. First of all, as shown in FIG.
Insert into the tapered hole 2 of. Then, first, the contact surfaces 24 and 31 of the free end portions of the joint portions 23 and 30 contact the inner peripheral surface 3 of the tapered hole 2. When the pull stud 18 is pulled in the direction of the arrow F by the pulling tool 5 in the above state, the insertion portion 10 has the tapered hole 2
In contrast, the state becomes a press-fitting state and the vehicle moves forward in the direction of its depth (left in FIG. 1). When the insertion portion 10 is advanced in this manner, the inner diameter of the inner peripheral surface 3 around the insertion portion 10 is narrowed, so that the contact surfaces 24 and 31 of the joint portions 23 and 30 are bent so that the diameter thereof is reduced. In this case, the diameters of the contact surfaces 24, 31 are the same as those of the joints 23,
The portions of the free end side of 30 are sequentially compressed and contracted, and the state shown in FIG. 2 is reached, and the inner peripheral surface 3 is elastically pressed against a wide contact area. Further, as described above, due to the advance of the insertion portion 10, the contact surface 11 is pressed against the end surface 4 as shown in FIG.
The holder 6 is in a predetermined mounting state with respect to the spindle 1. Incidentally, in this case, in many cases, a slight gap remains in the portion indicated by reference numerals 36 and 37 in FIG. 2 (the outer peripheral surface of the portion of each of the joint portions 23 and 30, which is continuous with the connecting portion 20). May be zero.

Since the contact surfaces 24 and 31 of the joint portions 23 and 30 are in pressure contact with the inner peripheral surface 3 of the tapered hole 2 in the above-mentioned mounted state, the axis of the holder 6 is accurate with respect to the main shaft 1. Matches
Further, when the spindle 1 is rotated in the above-mentioned mounted state to perform cutting, the holder 6 is laterally oriented (horizontally with respect to the axis of the holder 6) due to the cutting resistance of the cutter attached to one end of the main body 7. That is, for example, even if a force is applied in the vertical direction in FIG. 2, the contact surfaces 24 and 31 of the joint portions 23 and 30 are firmly joined to the inner peripheral surface 3 of the tapered hole 2 and the contact surface 11 is rigid to the end surface 4. The joining provides a great resistance to such lateral force and prevents runout of the holder 6. This has the advantage of helping to improve the accuracy of the cutting surface by the cutting tool.

Next, FIG. 4 shows a different embodiment of the present invention, in which the joining pieces 23e and 30e are provided so that the diameters of the contact surfaces 24e and 31e can be elastically reduced more easily. It shows an example in which a large number of slits 38, 39 are formed side by side in the circumferential direction at regular intervals. It should be noted that, in terms of function, the same or equivalent configuration as that of the previous figure and explanations may overlap,
The same reference numerals as in the previous figure are appended with the letter e, and the duplicated description is omitted.

[0015]

As described above, according to the present invention, when the holder 6 is attached to the main shaft 1, when the insertion portion 10 is inserted into the tapered hole 2, the outer peripheral surface of the insertion portion 10 is abutted. Interface 24,
When 31 contacts the inner peripheral surface 3 of the tapered hole 2 and the insertion portion 10 is further advanced in the deep direction of the tapered hole 2, the contact surfaces 24 and 31 contacting each other have a diameter of the inner peripheral surface of the tapered hole 2. The contact surfaces 24 and 31 are compressed by the surface 3 so that the contact surfaces 24 and 31 are the inner peripheral surface 3 of the tapered hole 2.
There is a feature that the contact surface 11 directly contacts the end surface 4 of the main shaft 1 while being pressed against. This means that the holder 6
Has the effect that the axis center can be attached with high accuracy.
Further, the holder 6 in the attached state can be made extremely strong against a lateral force, and when cutting is performed in the attached state, an extremely large effect of preventing runout can be exerted. Moreover, even if the contact surface 11 is directly brought into contact with the end surface 4 as described above, in the case of the above attachment,
As described above, the contact surfaces 24 and 31 on the outer circumference of the insertion portion 10 are compressed in diameter by the inner peripheral surface 3 of the opposite tapered hole 2, and the contact surface 11 contacts the end surface 4. ,
Even if there are some differences in the dimensions of the taper hole 2 and the end surface 4 of the spindle 1 depending on the machine tool manufacturer, the contact surfaces 24 and 31 are in pressure contact with the inner peripheral surface 2 and the contact surface 24 is in contact with the end surface 4. There is an advantage that a proper mounting state in which 11 contacts can be achieved and there is wide adaptability to various spindles 1. Further, as described above, the diameters of the contact surfaces 24, 31 on the outer circumference of the insertion portion 10 are compressed by the inner peripheral surface 3 of the opposite tapered hole 2 so that the contact surface 11 becomes the end surface 4.
Abutting against the inner peripheral surface 3 of the tapered hole 2 at the contact surfaces 24 and 31 even if the contact surfaces 24 and 31 and the contact surface 11 are slightly worn due to repeated attachment and detachment with respect to the spindle 1. Only by a slight change in the place of contact and the pressure contact force, the proper mounting state as described above can be achieved as it is, and therefore, there is an effect that it can be used for a long life.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which an insertion portion of a holder is inserted in a tapered hole of a spindle of a machine tool.

FIG. 2 is a sectional view showing a state in which the insertion portion is advanced toward the deep portion of the tapered hole.

FIG. 3 is a side view showing an insertion portion of the holder.

FIG. 4 is a side view showing another example of the insertion portion.

[Explanation of symbols]

 1 Spindle 2 Tapered hole 3 Inner peripheral surface 4 End surface 6 Holding tool 7 Main body 10 Insertion part 11 Present surface 27,34 Hollow part

Claims (1)

[Claims] 1. A tapered insertion portion for inserting into a tapered hole provided in a spindle of a machine tool is continuously provided at the other end of a main body having a tool mounting portion at one end, and the other end of the main body is provided. Around the periphery of the connecting portion of the insertion portion at the end, there is provided a contact surface for abutting against the end surface of the spindle when the insertion portion is inserted into the tapered hole, and the insertion portion has an outer periphery. In a holder having a contact surface for contacting an inner peripheral surface of the tapered hole, the insertion portion is provided inside the tapered hole on the inner side of the contact surface of the insertion portion. A holder provided with a hollow portion for bending the contact surface so as to reduce the diameter of the contact surface and pressing the contact surface against the end surface in a state of being press-fitted into the end surface.