JPH0155923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a generally cylindrical shank and at least two helical chip guide grooves exchangeably disposed in the forward head portion of the shank and extending rearwardly of the shank. The present invention relates to a boring tool having at least two cutting tools.

Such a known tool (DE 2730418) has increased utility. Despite very careful machining of boring tools and the cutting tools used therein, chips often lead to jamming or breakage of the cutting tools. Since this phenomenon generally occurs deep inside the hole, such disturbances are not immediately noticed and can sometimes lead to damage not only to the cutter itself but also to the boring tool. Generally, this type of damage occurs at the head of the shaft. In this case, the shaft part is damaged to the extent that it is no longer suitable for holding the knife satisfactorily. In existing boring tools, the head portion and the mounting portion are integrally constructed, or when replacing the tool, the entire tool must be replaced with a new tool. However, boring tools with a machining diameter of 50 mm or more are relatively expensive, and boring tools with a large machining diameter are generally not easily available. Therefore, in addition to replacement costs, a long supply period is required. Other disadvantages of existing boring tools are:
The point is that each tool is always used only for very defined machining diameters.

It is an object of the invention to repair damage caused to the head in a simple and substantially cost-saving manner and, if necessary, to machine internal bores of various diameters.
It is an object of the present invention to provide a type of boring tool suitable for use within a certain size machining diameter range.

According to the invention, this problem is solved as follows. That is, the shaft is composed of at least two parts, the attachment part is removably connected to the head part, and the rear face of the head part remote from the cutter abuts the corresponding radially extending planar front face of the attachment part. at least two cylindrical mounting pins are fixed to the front surface of the mounting portion, the mounting pins engage corresponding mounting holes in the end face of the head portion, and a retaining member is provided on the head portion for acting on the mounting pins. It is carried out by those who have been given.

In the event of major damage to the head of the boring tool, after the retaining member has been removed, the head can be removed from the mounting part and replaced with a new head. This new head is made from a fraction of the material required to make a complete boring tool, and is significantly less expensive than a complete boring tool because it eliminates much of the machining work required for the mounting section. The mounting part can continue to be used in any case. Suitable auxiliary means, such as boring templates, can be used to ensure that the newly prepared head part fits into already used and other available mounting parts. The boring tool according to the present invention has important functions as a mounting pin and a holding member that acts on the mounting pin. The mounting pin provides adequate force transmission between the head portion and the mounting portion in the circumferential and axial directions of the boring tool. However, these mounting pins are also used to position the head portion in a predetermined position relative to the mounting portion. This is important so that the wall of the chip guide groove in the head portion does not form a step or shoulder at the junction with the wall of the chip guide groove in the mounting portion. In fact, the presence of a shoulder impedes chip removal. Additionally, these mounting pins center the head portion relative to the mounting portion. Finally, the attachment pin also has the function of acting on or engaging the retaining member. This is an important feature since there is very little room available for accommodating the holding member when considering the chip guide groove formed in the mounting portion from the head and the additional refrigerant bore.

Another advantage of the device according to the invention is that, within a certain machining diameter range, it can be replaced with other head parts having a somewhat larger or somewhat smaller machining diameter in order to obtain different machining diameters. In addition, the different length head sections can be exchanged for another head section to obtain even greater boring depths.

An advantage of the device according to the invention is that between the head part and the attachment part at least one prosthesis can be inserted, the front face of which facing the head part being similar to the front face of the attachment part. The rear face facing the mounting part is designed in the same way as the rear face of the head part. This construction makes it possible to create a boring tool system with wide variability.
Mounting parts with various conical or tapered shafts that fit into the receptacles of many different machine spindles are made as so-called adapters and are interchangeable. The connection between the attachment part and the prosthesis is made in a manner similar to the conventional connection method between the head part and the attachment part. The joint between the brace and the mounting part is provided approximately at the location where the chip channel begins in a standard single-piece boring tool. By changing the mounting parts, the boring tool can be used with many different machine spindles. However, different lengths,
It is also possible to use different diameters of the prosthesis as required, and in either case the head portion can be fixed to the front surface of the prosthesis by means of the mounting pin and the retaining member. In this way, this boring tool is very easily adapted to the specific machining operation with respect to its length and its diameter. This type of multi-component boring tool has high vibration resistance because the length of each component is limited, their own vibration is low, and the vibration intensity transmitted at their joints is low. There is.

It is a fact that a boring tool having a so-called annular cone tip is known, in which the annular cone tip carries a replaceable cutting tool, and the front end of a hollow shaft portion is screwed. In these boring tools, the annular cone point also has the shape of a cylindrical hollow body. Chip removal in these boring tools takes place through the interior of the annular cone point and the interior of the shank. When connecting the annular conical point and the shaft, the conical point has an internal thread and the shaft has an external thread. However, this structure cannot be used for boring tools that have an outwardly opening chip channel in the shaft.

Other features of the invention are set out in the dependent claims.

The present invention will be described in detail below with reference to the drawings.

FIG. 5 shows a boring tool 1, which has a generally cylindrical body. The front head portion 3 of the torso, which is removable from the rear attachment portion 2 of the torso, includes:
A replaceable plate-shaped blade 4 is provided. Further, the body has two spiral chip guide grooves 5 that connect with the cutter 4, and these guide grooves 5 are open on the surface of the body. These chip guiding grooves 5 extend from the cutting tool 4 toward the mounting portion 2 of the body. At its rear end, the mounting part 2 has a conical part 6 which is adapted to fit on a machine tool.

The mounting part 2 shown in FIGS. 1 and 2 also has a central refrigerant hole 7 which connects to two or more refrigerant channels 8 provided in the head part 3, 3'. These refrigerant conduits 8 are located at the front end 3 of the head portion 3 near the cutter 4.
Open outward at a. The refrigerant is supplied to the center hole 7 through a refrigerant ring (not shown) surrounding the mounting part 2 and a horizontal hole 9 provided in the mounting part 2 (Fig. 5).
It will be carried out via. Referring to Figures 1 and 5,
In the first embodiment shown here, the head part 3 is removable from the attachment part 2. The head part 3 is shorter than the attachment part 2, and the joining means between the two parts 2, 3 are arranged in the area of the chip channel 5.

The head part 3 has on its rear face remote from the knife 4 a radially extending planar rear face 10 which abuts a corresponding radially extending planar front face 11 of the mounting part 2 . The front side 11 of the mounting part 2 has two diametrically opposed mounting holes 12 and these holes 12
It has a coaxial screw hole 13 that connects with. Furthermore, two mounting pins 14 are provided, and this pin 1
4 has a threaded tip 15 at its end facing the mounting part 2. The mounting pin 14 is screwed into the screw hole 13 by this tip 15, and the pin 14 is screwed into the screw hole 13.
engages with the mounting hole 16.

Two attachment holes 16 are provided in the rear surface 10 of the head portion 3, extending coaxially with the cylindrical attachment pins 14. The front end of the mounting pin 14 that protrudes beyond the front surface 11 is
It engages with these mounting holes 16. Therefore, head part 3
is arranged at a predetermined position with respect to the mounting part 2, so as can be seen from FIG. Accurately aligns with the wall.

At its front end, each mounting pin 14 has a transverse hole 17 extending perpendicularly to the axis B of the boring tool.
has. A holding pin 18 is slidably guided in this transverse hole 17. Furthermore, a retaining screw 19 is arranged in the head part 3, the axis of which likewise extends perpendicular to the axis B of the boring tool. The screw 19 has at its inner end a conical tip 20 which engages in a corresponding conical recess 21 in the retaining pin 18 . The retaining pin 18 further has a conical tip 22 at its inner end, which tip 22 is connected to the head portion 3.
The corresponding conical recess 23 is engaged with the corresponding conical recess 23 . The center Z of this conical recess 23 is arranged coaxially with the axis C of the screw 19. The apex angles of the conical tips 20 and 22 of the conical recesses 21 and 23 are preferably the same and approximately 90 degrees.

What is important is that the axis C of the screw 19 is aligned with the horizontal hole 17.
The problem is that it does not align exactly with the axis D of . The axis C of the screw 19 lies at a distance A from the rear face 10 of the head part 3, which distance is slightly greater than the distance a of the axis D of the transverse hole 17 from the front face 11 of the attachment part 2.
The difference between the two distances A and a is 0.5 mm.

When the screw 19 is tightened, its tip 20 abuts the side of the conical recess of the retaining pin 18 that is remote from the front surface 11. In this way, the retaining pin 18
is moved in the axial direction until its tip 22 abuts in the recess 23. As a result, a force in the direction toward the attachment part 2 acts on the head part 3, causing the rear face 10 and the front face 1
1 and strongly abuts. If the biasing force of the two screws 19 is, for example, 2000 kp, a force of 4000 kp will be generated in each screw 19 in the direction toward the boring tool axis, so the contact force of the head portion with the mounting portion 2 will be a total force of 8000 kp. is generated. This power is
Mounting pin 14 subjected to shear forces, especially due to torque
This is more than sufficient for transmitting torque via

If damage occurs to the head portion 3, the retaining pin 18 can be removed by simply removing the retaining screw 19.
To facilitate this, each retaining pin 18 may be provided with a threaded hole into which a long pin, also threaded, is screwed into the front end. This pin allows each holding pin to be extracted from the transverse hole 17. The head part 3 is then pulled out from the mounting pin 14 and replaced with a new head part. It is therefore only necessary in each case to replace the head part 3. The amount of material required to make the head portion 3 is only about 1/7 of the material required for the entire boring tool.

In the second embodiment shown in FIGS. 2 to 4, the same reference numerals are used for parts having the same functions as those in the first embodiment, so the above description applies to this embodiment as is. However, in this embodiment, the mounting pin 14' has a longitudinal hole 24.
By means of a fixing screw 25 passing through this longitudinal hole 24 and engaging in the screw hole 13, the mounting pin 14' is fixedly connected to the mounting part 2. In the head part 3', a retaining screw 19 is screwed in at right angles to the axis of the mounting pin 14'. This retaining screw 19
engages in the annular recess 26 by its conical tip 20, the cross-section of the tip 20 of the screw 19 being conically inclined towards the axis of the mounting pin 14'. Also, in this arrangement, the axis C of the retaining screw 19 is spaced from the rear face 10 of the head part 3 by a distance A, which is slightly larger than the distance a of this axis C from the front face 11 to the center Z of the recess 26. When the retaining screw 19 is tightened, its tip 20 abuts the recess 26 on one side thereof, forcing the head portion 3' into abutment with the front face 11 at the rear face 10. To replace the head part 3', simply unscrew the retaining screw 19 slightly.

In the third embodiment shown in FIGS. 6 and 7, parts having the same functions as those in the previous example are denoted by the same reference numerals. The explanation is equally applicable in this case. However, in this example,
The retaining pin 18' and the retaining screw 19' have a somewhat different configuration. This holding pin 18' has conical tips 22, 22a at both ends thereof. The tip 22 engages in a conical recess 23 provided in the head part 3. The tip 22a cooperates with a conical recess 27 provided in the retaining screw 19'. Again, the axis C of the retaining screw 19' is spaced from the rear face 10 by a distance A, which distance is slightly greater than the distance a from the front face 11 to the axis D of the transverse bore 17. When the retaining screw 19' is tightened, its conical recess 27
It comes into contact with the side surface of the tip portion 22a on the first side. As a result, the holding pin 18' has its tip 22 in the recess 2.
3, it is moved in the axial direction until it abuts on the side of the front surface 11, as in the previous example. In this way, a force in the direction of the attachment part 2 acts on the head part 3, bringing the end face 10 into firm abutment against the front face 11.

Preferably, the length of the retaining pin 18' is slightly shorter than the diameter of the mounting pin 14. Therefore, when the retaining screw 19' is removed and the two parts 3, 2 are separated from each other, the retaining pin 18' enters completely into the transverse hole 17. The retaining pin 18' has its tip 22
has a conical shape and is pushed into the transverse hole 17 because of this and the conical recess 23 . Tip portions 22, 22
The apex angle of a is also about 90° in this embodiment.

In order to adapt the boring tool to various situations involving machining, in this third embodiment an interposition 28 can be inserted between the head part 3 and the mounting part 2, the interposition of which The front side 11 is designed similarly to the front side 11 of the mounting part 2' and faces the rear side of the head part 3, the rear side 10 facing the rear side 10 of the head part 3.
It is designed to face the front surface of the mounting portion 2'. Therefore, the mounting pin 14
A radially extending flat front surface 11 having a radially extending flat surface 11 is provided at the forward end 28a and has a corresponding mounting hole 16.
A flat rear surface 10 is provided at the rear end 28b. The diameter of the mounting pin 14 and the mounting hole 16,
and their radial distance from the axis of the boring tool corresponds to a corresponding arrangement in the head part 3 and in the attachment part 2' in the prosthesis 28;
If necessary, the head part 3 can be attached directly to the mounting part 2.

In this third embodiment, if the head part 3 is damaged, it can be replaced in the same manner as in the previous embodiment. However, in addition, the mounting part 2' can also be replaced.
This is necessary, for example, if the boring tool is used in another machine with a different receptacle, such as a receptacle with a different cone angle for the cone 6 of its mandrel. In this case, the attachment part 2' is replaced by another attachment part whose conical part 6 is adapted to the corresponding receptacle. Instead of a conical shape, the mounting part 2' can also have the form of a cylindrical shaft or a fixed flange.

Furthermore, by using various braces 28, the boring tool can be very well adapted to specific machining operations. Various lengths of braces 28 can be used, and even more than one brace can be used, for example. Furthermore, it is also possible to attach prostheses with a somewhat larger or smaller diameter to the shaft part 2', in which case head parts with a corresponding diameter are attached to these prostheses.

The interposer 28 also includes a suitably helical chip guide groove 5. However, in FIG. 6, these chip guide grooves 5 are not shown in order to simplify the drawing.
is shown as a straight line. It is preferable that the connection between the interposition tool 28 and the mounting portion 2' be provided at a position where the chip guiding groove 5 is not formed.

The invention is not limited to the embodiments described above. Thus, for example, it is also possible to attach a conical or annular rearwardly designed head part to the attachment part 2' shown in FIG.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal front view of a first embodiment of the invention, FIG. 2 is a front view of the second embodiment, and FIG. 3 is a second embodiment taken along the line - in FIG. FIG. 4 is a sectional view taken along the line - of FIG. 3, FIG. 5 is a front view of the first embodiment, and FIG. 6 is a third embodiment of the invention. The front view of the example, FIG. 7 is a longitudinal sectional front view of a part of the same as above. 1... Boring tool, 2, 2'... Mounting part, 3,
3'...Head part, 4...Blade, 5...Chip guide groove,
6... Conical part, 10... Rear surface, 11... Front surface,
12...Mounting hole, 13...Screw hole, 14, 14'
...Mounting pin, 15...Tip, 16...Mounting hole, 17...Horizontal hole, 18, 18'...Retaining pin,
19, 19'... Holding screw, 20... Conical tip, 21... Conical recess, 22, 22a... Conical tip, 23... Concave, 24... Vertical hole, 25
... Fixing screw, 26 ... Annular recess, 27 ... Recess, 28 ... Intervention device.

Claims (1)

[Scope of Claims] 1. A substantially cylindrical shank; and at least two helical chip guiding grooves convertably arranged in the front head portion of the shank and extending rearwardly of the shank. In a boring tool having two cutting tools, the shaft portion consists of at least two parts, a mounting portion 2, 2' and a head portion 3, 3', both of which are removably connected to each other, and the head portion is connected to the cutting tool 4. abuts a corresponding radially extending planar front surface 11 of the mounting part 2, 2' by means of a radially extending planar rear surface 10 remote from the at least two cylindrical mounting pins 14, 14'. are fixed to the front face 11 of the mounting parts 2, 2', the mounting pins 14, 14' fit into corresponding mounting holes 16 formed in the rear face 10 of the head parts 3, 3', ’ mounting pin 14,
A boring tool characterized by comprising holding members 19, 19' for locking or releasing the locking member 14' to the head portions 3, 3'. 2 The head parts 3, 3' are shorter than the mounting part 2,
The boring tool according to claim 1, characterized in that the joint between these two parts is located in the area where the chip guiding groove 5 is formed. 3 At least one interposition 28 is insertable between the head part 3 and the attachment part 2', the interposition 28
8 is characterized in that its front face facing the head part 3 is designed similarly to the front face of the attachment part 2', and its rear face facing the attachment part 2' is designed similarly to the rear face of the head part 3. A boring tool according to claim 1 or 2. 4 Each mounting pin 14, 14' has a screw connection means 13,
15, 25 to the attachment part 2 or the prosthesis 28.
Boring tool as described in paragraph 3 or paragraph 3. 5 The mounting pin 14 is attached to the mounting portion 2' or the interposition device 28
Claim 1 characterized in that it has a distal end portion 15 with a thread facing towards the end, which distal end portion is threadedly engaged in a threaded hole 13 formed in the attachment part 2, 2' or in the prosthesis 28. Boring tools as described in Scope 4. 6 The mounting pin 14' has a center hole 24, and the hole 2
4. The boring tool according to claim 4, wherein a fixing screw 25 threadably engaged with the mounting portion 2, 2' or the interposition device 28 passes through the hole. 7 a retaining screw 19 whose retaining member threads into the head portion 3, 3' in a direction perpendicular to the axis E of the attachment pin and whose tip 20 engages in the recess of the attachment pin 21, 26; A boring tool according to claim 1 or 3, characterized in that the boring tool comprises: 8 The tip 20 is conical, and the recesses 21 and 26
8. The boring tool according to claim 7, wherein the mounting pin is inclined conically toward the axis E of the mounting pin. 9 The axis of the retaining screw 19 is aligned with the front surface 1 of the mounting part 2.
1 to the center Z of the recesses 23, 26 from the rear surface 10 of the head portions 3, 3' by a distance A slightly greater than the distance a from the center Z of the recesses 23, 26. Boring tool. 10 Each mounting pin 14 has a transverse hole 17 extending perpendicularly to the axis B of the boring tool, and the axis D of the transverse hole extends from the rear surface 10 to the axis C of the retaining screw 19.
A retaining pin 18 is slidably guided in the transverse hole 17 and is spaced from the front face 11 of the mounting part 2 by a distance a slightly smaller than the distance A to
The outer end facing the retaining screw 19 of 8 is a conical recess 21
and whose inner end engages in a conical recess 23 provided in the head part 3 by means of a conical tip 22, the center Z of which recess 23 being aligned with the axis C of the retaining screw 19.
A boring tool according to claim 7 or 8, characterized in that the boring tool is arranged coaxially with. 11 Each mounting pin 14 has a horizontal hole 17 extending perpendicularly to the axis B of the boring tool, and the distance a between the axis D of the horizontal hole 17 and the front surface 11 of the shaft portion 2'
is slightly smaller than the distance A from the rear surface 10 of the head part 3 to the axis C of the retaining screw 19' screwed into the head part 3 in a direction perpendicular to the axis of the mounting pin 14, and the retaining pin 18' The retaining pin 18' is slidably guided in the transverse bore 17 and has a conical tip 22a in the conical recess 27 of the retaining screw.
, and its inner end engages in a conical recess 23 formed in the head part 3 by a conical tip 22, the center Z of which is aligned with the axis C of the retaining screw 19'.
The boring tool according to claim 1, characterized in that the boring tool is arranged coaxially with. 12. The boring tool according to claim 11, wherein the length of the holding pin 18' is smaller than the diameter of the mounting pin 14. 13 Tips 20, 22, 22a and recess 2
A boring tool according to any one of the preceding claims, characterized in that the apex angles of the points 1, 23, and 27 are of the same size and approximately 90 degrees.