JP3513679B2 - Holding tool - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holder for holding a cutting tool for machine work, such as a drill or an end mill, and more particularly, to a structure of a mounting portion of the holder for a machine tool. About. 2. Description of the Related Art The following is known as this type of holder. That is, an insertion portion for inserting into a tapered hole provided in a main shaft of a machine tool is continuously provided at the other end of the main body having a tool mounting portion 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 body is provided at one end of the main body, around a continuous portion of the insertion portion, for contacting the end surface of the main shaft, and the contact surface is sandwiched between the end surface and the corresponding surface. (For example, Japanese Patent Laid-Open No. 5-3)
No. 37769). In such a configuration, when the insertion portion is inserted into the tapered hole, the elastic body comes into contact with the end face 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, and both are firmly joined. As a result, the holder is attached to the main shaft with high accuracy in matching the axis. 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 abutment surface and the end surface. As a result, the holding tool has an increased strength against the lateral force applied thereto, and when the main shaft is rotated to perform the cutting process, the runout of the holding tool can be prevented. By the way, in order to further improve the effect of preventing the run-out of the core, 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 main shaft. It was thought. In such a case, in addition to the rigid joining of the outer peripheral surface of the insertion portion to the inner peripheral surface of the tapered hole, the contact surface is also rigidly joined to the end surface, so that the above-described core runout preventing effect can be significantly improved. [0005] However, since the spindle of the machine tool is manufactured under the control of various machine tool manufacturers, and each has a slight difference in the dimensions of the tapered hole and the end face, a specific spindle is required. Even when the outer peripheral surface of the insertion part and the contact surface come into contact with each other as described above when mounting on the main shaft of the manufacturer, when it is mounted on the main shaft of another company, there is a gap on either the outer peripheral surface or the main surface. There was a problem that could be done. Furthermore, when the outer peripheral surface or the abrasion surface is worn by repeatedly attaching and detaching to and from the main shaft of the machine tool during use, any one of them will not be able to hit the other party.
There is also a problem that the life is relatively short and limited. [0006] The holder of the present invention is provided to solve the above-mentioned problems (technical problems) of the prior art. A first object is to allow a holder to be attached to a main shaft with high accuracy of alignment of an axis. The second purpose is
By making the abutment surface of the holder directly contact the end face of the main shaft of the machine tool, the proof stress against the lateral force applied to the holder is extremely increased. That is, the effect of preventing run-out of the core can be exhibited. A third object is to allow the machine tool to be mounted in a state where the above-described large center runout preventing effect is exhibited even if the dimensions of the tapered hole and the end face of the main shaft of the machine tool are different. A fourth object is to enable the use of a long life by being mounted in such a state that the above-described large center runout preventing effect is exerted even if some wear occurs due to repeated attachment / detachment to the main shaft. It is to be. Other objects and advantages will become more readily apparent from the drawings and the following description associated therewith. According to the present invention, there is provided a holding tool having a taper for inserting into a tapered hole provided in a main shaft of a machine tool at the other end of a main body having a tool mounting portion at one end. The main body is connected to the end face of the main shaft in a state where the insertion portion is inserted into the tapered hole around the connection portion with the insertion portion at the other end of the main body. Wherein the insertion portion has an abutment surface on an outer peripheral surface thereof for abutting against an inner peripheral surface of the tapered hole. A base located at the center of the part, and integrally formed with the continuous part;
A sleeve formed separately on the outer periphery of the base,
A sleeve having an abutment surface formed on an outer periphery thereof so as to abut against an inner peripheral surface of the tapered hole when the insertion portion is inserted into the tapered hole. The intermediate position in the longitudinal direction connects the inner peripheral surface to the base as a connecting portion to the base, and forms an escape portion between the outer peripheral surface of the connecting portion and the inner peripheral surface of the tapered hole. On the outer peripheral surface of the joining portion located closer to the contact surface than the connecting portion, the gradient of the inner peripheral surface in a state before the insertion portion is advanced toward the deep portion so as to be pressed into the tapered hole. A contact surface with a greater gradient is provided, and the insertion portion 10 is press-fitted into the tapered hole 2 on the outer peripheral surface of the joint located deeper than the connecting portion in the sleeve. In the depth direction In previous state of advancing, let includes a contact surface with a smaller slope than the slope of the inner peripheral surface 3, and the respective junction between the outer periphery of the base,
A hollow portion is provided to bend each of the joints so as to reduce the diameter thereof so that the contact surface comes into contact with the end surface of the spindle. 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 toward the deep portion of the tapered hole, the contact surface is bent by the inner peripheral surface of the tapered hole so as to reduce its diameter and pressed against the inner peripheral surface of the tapered hole, The contact surface directly contacts the end surface 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. Also, the abutment of the holder against the end surface increases the strength of the holder against a lateral force. An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, reference numerals 1 to 5 denote well-known structures in a machine tool, 1 is a main shaft, 2 is a tapered hole for attaching a holder provided at an end thereof, and 3 is an inner peripheral surface thereof. , In a tapered shape. The gradient of the inner peripheral surface 3 is, for example, 7/2.
4 gradients. Reference numeral 4 denotes an end surface of the main shaft 1, and reference numeral 5 denotes a pulling tool for attaching a holder. Next, reference numeral 6 denotes 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. A section 9 is provided. One end (the right end not shown in the drawing) of the main body 7 is provided with a tool mounting portion for detachably mounting a cutting tool such as a drill and an end mill. The tool mounting part may be a mounting part to which a cutting tip is directly mounted, in addition to the detachable mounting part as described above. [0010] Next, reference numeral 10 denotes an insertion portion connected to the other end 7a of the main body 7 for inserting the holder 6 into the tapered hole 2 and fixing the holder 6 to the main shaft 1. It is formed in a tapered shape for insertion. 11 is the above insertion part
A contact surface for contacting the end surface 4 in a state where 10 is inserted into the tapered hole 2, and is provided around the connecting portion 7a of the insertion portion at the other end of the main body 7 as shown in the figure. The above insertion part
In order to easily form a structure having the hollow portions 27 and 34 as described later, in this example, the base 10 is formed integrally with the main body 7 and the sleeve is provided on the outer periphery thereof. It consists of 13. 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
Reference numeral 16 denotes a positioning breakage, which is a retaining ring for retaining the sleeve, and is fitted in a groove provided on the outer peripheral surface of the base 12. 17
Is a collar interposed between the sleeve 13 to prevent the end face of the sleeve 13 from being damaged by the retaining ring 16, 18 is a well-known pull stud for receiving the pulling operation by the pulling tool 5, and a base 12
Screwed into the mounting hole. Next, the sleeve 13 will be described. 20
Indicates a connecting portion to the base portion 12, and is connected to the mounting portion 14 by press fitting in order to improve the alignment accuracy of the axis of the base portion 12 and the sleeve 13 at the time of assembly to the mounting portion 14. Reference numerals 21 indicate an inner peripheral surface for joining to the mounting portion 14. Reference numeral 22 denotes an outer peripheral surface of the connecting portion 20, and a tapered hole 2
In order to ensure that the outer peripheral surface of the joining portion described below can be joined to the inner peripheral surface 3 of the inner peripheral surface 3, a relief portion is provided 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 the production of the sleeve 13. Reference numerals 23 and 30 denote joining 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 a contact surface for pressing against the inner peripheral surface 3 of the tapered hole 2. These contact surfaces 24 and 31 are
Is pressed into the tapered hole 2 so that when the contact surfaces 24 and 31 are 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 as large an area as possible. For this purpose, the free ends of each of the joints 23, 30 (joint 20
(The end on the opposite side to the connecting portion) is brought into contact with the tapered surface 3. For that purpose, the contact surface 24 is formed with a gradient greater than the gradient of the inner peripheral surface 3 and the contact surface 31 is formed with a smaller gradient. Inner peripheral surfaces 25, 32 of both joints 23, 30 are hollow inside the contact surfaces 24, 31 to enable the diameter of the contact surfaces to be reduced as shown in the figure. So that 27 and 34 are formed
It is formed slightly larger than the outer peripheral surfaces 26 and 33 of the base 12 of the corresponding portion. Next, the attachment of the holder 6 having the above-mentioned structure to the spindle 1 will be described. First, as shown in FIG.
Into the tapered hole 2. Then, the contact surfaces 24, 31 of the free ends of the joints 23, 30 first come into contact with the inner peripheral surface 3 of the tapered hole 2. When the pull stud 18 is pulled in the direction of arrow F by the puller 5 in the above state, the insertion portion 10
And presses forward in the deep direction (leftward in FIG. 1). When the insertion portion 10 advances in this manner, the inner diameter of the inner peripheral surface 3 around the insertion portion 10 becomes narrower, so that the contact surfaces 24 and 31 of the two joining portions 23 and 30 bend so as to reduce the diameter. In this case, the diameter of the contact surfaces 24, 31
30 are sequentially pressed and contracted from the free end side, and the state shown in FIG. 2 is brought into a state of being elastically pressed against the inner peripheral surface 3 in a wide contact area. Further, as described above, the abutment surface 11 is pressed against the end surface 4 as shown in FIG.
The holder 6 is in a predetermined attachment state with respect to the main shaft 1. In this state, a small gap often remains at the portions indicated by reference numerals 36 and 37 in FIG. 2 (the outer peripheral surfaces of the portions connected to the connecting portions 20 at the joints 23 and 30). May be set to zero. In the above mounting state, the contact surfaces 24, 31 of the joints 23, 30 are pressed against the inner peripheral surface 3 of the tapered hole 2, so that the axis of the holder 6 is accurate with respect to the main shaft 1. Matches.
When cutting is performed by rotating the main shaft 1 in the above-described mounting state, the cutting tool attached to one end of the main body 7 faces the holder 6 sideways due to the cutting resistance (the sideways direction with respect to the axis of the holder 6). That is, for example, even if a force in the vertical direction in FIG. 2 is applied, 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 firm to the end surface 4. The joining exhibits a large resistance to such a lateral force, and prevents the holder 6 from swaying. This has the advantage of improving the accuracy of the cutting surface with the cutting tool. FIG. 4 shows another embodiment of the present invention. In order to make it easier to elastically reduce the diameters of the contact surfaces 24e and 31e, the connecting pieces 23e and 30e are provided with joints 23e and 30e. This shows an example in which a large number of slits 38, 39 are arranged at regular intervals in the circumferential direction. Note that, in terms of functionality, the description is considered to be duplicated with the same or equivalent configuration as that of the previous figure,
The same reference numerals as those in the previous figure are given an alphabetic letter e, and redundant description is omitted. 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 periphery of the insertion portion 10 is formed. Contact surface 24,
When the contact 31 comes into contact with the inner peripheral surface 3 of the tapered hole 2 and the insertion portion 10 is further advanced in the depth direction of the tapered hole 2, the diameter of the contact surfaces 24, 31 that have come into contact with the inner peripheral surface 3 of the tapered hole 2 The contact surfaces 24 and 31 are compressed by the surface 3 so that the inner peripheral surface 3
And the contact surface 11 directly contacts the end surface 4 of the main shaft 1. This means that the holder 6
Has the effect that it can be mounted with high accuracy of its axis center,
Furthermore, when the holder 6 in the mounted state can be made extremely strong against the lateral force, and cutting is performed in the mounted state, there is an effect that an extremely large center runout preventing effect can be exhibited. Moreover, even if the contact surface 11 is brought into direct contact with the end surface 4 as described above,
As described above, the contact surfaces 24 and 31 on the outer periphery of the insertion portion 10 are reduced in diameter by the inner peripheral surface 3 of the mating tapered hole 2, and the contact surface 11 contacts the end surface 4. ,
Even if there are some differences in the dimensions of the tapered hole 2 and the end face 4 of the main spindle 1 depending on the machine tool maker, the contact faces 24 and 31 are pressed against the inner peripheral face 2 and the contact face is pressed against the end face 4. There is an advantage that a proper mounting state in which the abutment 11 comes into contact can be achieved, and there is a wide adaptability to various spindles 1. Further, as described above, the diameter of the contact surfaces 24 and 31 on the outer periphery of the insertion portion 10 is compressed by the inner peripheral surface 3 of the counterpart tapered hole 2 so that the contact surface 11 becomes the end surface 4.
Contact with the inner surface 3 of the tapered hole 2 at the contact surfaces 24, 31 even if the contact surfaces 24, 31 and the contact surface 11 are slightly worn by repeated attachment and detachment to the spindle 1. The above-mentioned proper mounting state can be achieved as it is, with only a slight change in the contact location and the press contact force, and therefore, there is also an effect that a long life can be utilized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a state where an insertion portion of a holder is inserted into a tapered hole of a main shaft of a machine tool. FIG. 2 is a cross-sectional view showing a state where an insertion portion is advanced toward a deep portion of a tapered hole. FIG. 3 is a side view showing an insertion portion of the holder. FIG. 4 is a side view showing a different example of the insertion portion. [Description of Signs] 1 Main shaft 2 Tapered hole 3 Inner peripheral surface 4 End surface 6 Holder 7 Main body 10 Insertion section 11 Immediate plane 27, 34 Hollow section

Claims (1)

(57) [Claim 1] A tapered insertion portion for inserting into a tapered hole provided in a main shaft of a machine tool at the other end of a main body having a tool mounting portion at one end. Around the continuous portion with the insertion portion at the other end of the main body, a contact surface for contacting the end surface of the main shaft in a state where the insertion portion is inserted into the tapered hole. Equipped,
In the holder, wherein the insertion portion has an abutment surface on an outer peripheral surface for abutting the inner peripheral surface of the tapered hole, the insertion portion is located at a central portion of the insertion portion, and , One with the connecting part
A base formed on the body and a separately formed sleeve provided on the outer periphery of the base,
Insert the insertion part into the tapered hole on the outer circumference
The contact surface for contacting the inner peripheral surface of the tapered hole
And a sleeve that is formed.In the sleeve, the intermediate position in the longitudinal direction of the sleeve is
Connect the inner peripheral surface to the base as a connection to the base, and connect
In the outer peripheral surface of the portion, between the inner peripheral surface of the tapered hole
Constructs a relief part, and further from the connection part in the sleeve
Also, on the outer peripheral surface of the joint located on the contact side, insert
Deep into the taper hole so that it is press fit
In the state before moving forward,
With a contact surface with a large gradient
Of the joint located deeper in the tapered hole than the connecting part
The insertion portion 10 is pressed into the tapered hole 2 on the outer peripheral surface.
Before moving forward in the depth direction
Abutment having a gradient smaller than the gradient of the inner peripheral surface 3
A surface is provided between the joints and the outer periphery of the base.
Bend the joint to reduce its diameter and raise the
A hollow portion is provided for contact with the end face of the spindle
A holding tool characterized by the above-mentioned.