JPS5937390B2 - rock boril - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises at least one swarf groove in the periphery;
The present invention relates to a rock drill equipped with a drill shank having a horizontal slit into which a plate-shaped cutter made of cemented carbide is attached to the drill head, particularly in the axial plane of the drill shank.

The invention aims to design a rock drill of this type in such a way that when the drill bit becomes worn, a new sharp cutter can be prepared again in a short time with a simple construction, and the cutter can be safely held. Take it as a challenge.

In the rock drill according to the invention mentioned at the beginning, this means that the rock drill is equipped with a drill shank, the drill shank having at one end a transverse slit for a plate-shaped cutter, and the cutter having a transverse slit in the transverse slit. In the case where the holding member is removably fixed in the hole, the holding member is a pin located transversely to the drill axis, the pin is located inward from the outer peripheral surface of the drill, and is made of a hard metal. The hard metal cutter is fitted into the hole of the cutter, and the hard metal cutter is supported at the bottom of the horizontal slit over almost the entire length of the horizontal slit. This is obtained by having a centering projection by means of which the cutter is supported by a surface at the bottom of at least one of the transverse slits.

As a result, the cutter can be quickly replaced at any time, the pin arrangement according to the invention ensuring a very secure holding.

In a simple embodiment, the pin is located at right angles to the plane of the cutter, but the pin is then engaged only over a short part of its length.

If the pin is located parallel to the plane of the cutter, the pin is actually engaged in the cutter over the cutter's cutting and into the drill shank.

It is likewise expedient if the pin is located approximately symmetrically to the cutter.

The axis of the pin crosses the axis of the drill to obtain the best possible surface finish.

To further simplify the construction of the rock drill, the pin is inserted into a through hole, in particular a hole in the cutter blade or a hole in the drill shank.

However, the pin fits into a groove, particularly a groove in the cutter blade or drill shank whose cross section matches that of the pin, so that the cross section of the cutter blade or the drill shank is completely perfect for receiving the pin. It is considered that it does not penetrate.

In a simple embodiment, the groove is provided on the side of the cutter or on the side of the transverse slit of the drill shank, the groove being able to engage in the cutter blade throughout its cutting,
As a result, the pin can be easily engaged and withdrawn again.

In order to obtain a very safe guidance of the pin, at least one groove, in particular in the drill shank, is formed with an undercut.

The groove of the cutter and the groove of the drill shank form a through hole for the pin, so that the pin is held securely and a strong connection between the cutter and the drill shank is ensured.

Therefore, despite a relatively large pin cross-section, a very thin cutter blade can be used, the groove of the cutter being shallower than the groove of the drill shank, in particular about 4 degrees of the groove of the drill shank.

A particularly advantageous further embodiment of the object according to the invention is that the pin is displaced at the bottom of the transverse slit opposite to the central axis of the recess of the cutter 17, so that the pin engages transversely to its longitudinal direction. The purpose of this is to press the cutter with the sides towards the bottom of the slit and to therefore prestress the cutter in such a way that a completely play-free holding of the cutter is ensured.

This means that the recess, in particular the recess for the pin in the cutter, is formed by an elastic spring element which is mounted in a corresponding large receiving opening, the spring element being formed in a simple manner by a spring sleeve; In particular, it can be of rubber-elastic design.

It may be considered to provide bolts as pins.

However, a very simple construction and handling is obtained if the pin is formed by a press-fit pin, in particular a helical clamp pin.

In order to obtain a safe support and to avoid relative movements between the cutter blade and the drill, the cutter contacts the bottom of the transverse slit with the edge opposite the cutting edge, in particular over approximately the entire diameter of the drill shank.

Another way to increase the strength of the drill is to provide a transverse slit or pin in the drill head, in particular with the end of the swarf groove approximately parallel to the axis relative to the drill, so that a good direct contact from the drill tip is achieved. This can be achieved by ensuring swarf evacuation.

This is further improved if the swarf grooves are located at a distance from the transverse slit or pin on both sides of the pin.

Very good swarf evacuation is achieved especially with high drill strengths, especially when the end of the swarf groove has a helical swarf spaced from the bottom of the transverse slit in the direction relative to the center of the drill shank at the end opposite the drill tip. Occurs within the range of the drill tip when transitioning into the groove.

However, according to the invention it is also conceivable for the drill to have only one or two axis-parallel lateral flat grooves or slopes on its periphery for removing the cuttings.

In order to strengthen the cross section of the drill head, the width at the end of the swarf groove is smaller than the width of the helical swarf groove.

According to the present invention, two or four swarf grooves are provided, so that even if a large number of swarfs are carried out as a result of milling, they can be carried out quickly.

In order to obtain a long service life of the drill, the edges of the particularly polygonal cutter, which can have one or more edges, are formed by cutting edges that form obtuse angles to each other and are located symmetrically with respect to the drill axis. Ru.

Each cutting edge located approximately in the central plane of the cutter is expediently formed by rounding off the edge of the cutter.

The cutter has a very wide support surface on the drill head when the cutter is located away from the center of the cutter and the rounded edge of the cutter blade touches the edge of the transverse slit, so that only the rounded part protrudes. has.

The optimum shape is hereby achieved by the drill head having a conical end, the cone being in particular greater than the cutting edge angle of the cutter or equal to the angle between the two cutting edges of the cutter. .

In order to further improve the swarf channel removal, the end of the swarf channel is guided to the conical end of the drill head, in particular with its edge directly adjacent to and parallel to the edge of the transverse slit. occupies

In an advantageous configuration, the arrangement is such that the conical end of the drill head is located on the side of the blade at a distance from the pin, so that the pin can be retained in the drill shank over the entire diameter of the drill shank. .

In order to obtain a very precise alignment of the cutter relative to the drill shank, the bottom of the transverse slit has a centering recess for the insertion of the cutter projection.

The centering recess is produced, for example, by V-shading of the bottom of the transverse slit, so that a square centering hole is obtained.

However, it is also particularly contemplated that the flat bottom of the transverse slit is oriented approximately at right angles to the drill axis and that the cutter is provided with a projection that corresponds, in particular, approximately to the middle of the length of the rectangular centering recess. Ru.

A particularly advantageous embodiment of the object of the invention is that the cutter is approximately center symmetrical and is designed as a deflection plate, so that the cutter has at least two, in particular diametrically opposed, blades, so that one cutter itself can be multiplied several times by deflection. It can be used for.

If only two opposing blades are provided, it is expedient for the edge of the deflection plate joining these blades to be shorter than the cutting blade, so that the depth of the transverse slit is selected to be relatively small. Must be.

In particular, all edges of the hexagonal turning plate are formed as cutting edges,
As a result, it is possible in an advantageous manner for example for three blades to be used with each two cutting edges.

The pin according to the invention can only serve to prevent the cutter from being lost in the drill, while the pin cannot actually be subjected to the full force when machining with the drill, because of the cutting stiffness that occurs during machining. This is because the cutter is pressed into the drill shank or transverse slit.

Therefore, only the cutter blade is exposed to wear, and the shank of the drill is extended as far as possible to the sides of the cutter beyond the circumference of the drill head, in particular by a little less than the width of the beveled part forming the cutting edge. stand out.

The invention will now be described in detail.

The figures show several embodiments with the essential parts of the invention drawn to scale.

This part will be explained based on the figures.

As shown in Figures 1 to 4, the drill according to the invention has a shank 1, the shank 1 is provided with a helical cutting groove 2, and has a drill head 3 at the working end, the drill head being The swarf groove ends in front of the drill head 3 in such a way that it has a particularly large cross section.

The end 4 of the drill head 3 is shaped like an obtuse cone.

A horizontal slit 5 is provided in the drill head 3 symmetrically with respect to the axis parallel to the drill shank 1, and the bottom 6 of the horizontal slit has an obtuse angle V symmetrical to the drill axis when viewed at right angles to the side surface 7 of the horizontal slit. shaped, the -angle of the base 6 being equal to the cone angle of the end 4 of the drill head 3.

The bottom 6 of the horizontal slit 5 has an acute-angled v-shape in cross section.

A through hole 8 is provided in the drill head 3 at right angles to the central plane of the horizontal slit 5, the central axis of the through hole 8 intersects the drill axis, and the end 4 of the drill head 3 and the bottom 6 of the horizontal slit 5 A through hole is provided at the end 4 of the drill head 3 approximately in the center between the tips of the drill head 3.
It is located so that it is provided in a substantially cylindrical portion on the outside of.

At both ends of the transverse slot 5, approximately diagonally or diametrically opposite, two ends 9, 10 of the swarf groove 2 are provided, the ends 9, 10 lying in a common axial plane of the drill shank 1. One side 11 of each right-angled cross section is parallel to the center plane of the horizontal slit 5, and the other side is parallel to the hole 8.
is located parallel to the central plane of , in which case the side 11 is directly adjacent to the edge 13 formed by the corresponding side surface 7 of the transverse slit 5 and the conical outer surface of the end 4 of the drill head 3 and to which so that they are positioned parallel to each other.

One groove end 9 transitions chamfered to the end of the helical swarf groove 2 in the drill head 3, while the other groove end 10 transitions into the helical swarf groove 2 remote from this end.

A flat, center-symmetrical cutter blade 14 is attached to the lateral slit 5 of the drill head 3, and the cutter blades 14 have side surfaces 15 that are located parallel to each other and are substantially in full contact with the side surface 7 of the lateral slit 5.

The regular hexagonal cutter blade 14 has cutting edges 16 that are obtuse to each other and intersect with each other, each of which has an inclined surface of the cutting edge of the cutter blade 14 located symmetrically with respect to the center plane of the cutter blade 14. 17, the inclined surfaces 17 lying at an acute angle to one another.

The two respective adjacent cutting edges form a drill bit 18 and a drill tip 19 located in the drill axis.

The distance between the mutually parallel cutting edges 16 is two cutting edges 16 in each case compared to the diameter of the drill head 3 or the drill shank 1.
is slightly larger so that it projects slightly laterally beyond the circumference of the drill head 3 and lies axially parallel to the drill.

The V-shaped and ■-shaped cross section of the bottom 6 of the transverse slit 5 means that when the cutter blade 14 is installed, the two cutting edges 16 and the associated inclined surface 17 are in contact with the bottom 6 on almost the entire surface, so that a centering projection is formed. 20, whose protrusion prevents the cutter blade from moving laterally in the transverse slit 5.

In the mounted cutter blade, the inner edge 21 of the inclined surface 17 forming the cutting edge 18 lies over its entire length at the edge 13 of the transverse slit 5, while the cutting edge 16 parallel to the drill axis
The inner edge of the inclined surface 17 is located inside the side edge 22 of the horizontal slit 5.

The cutter blade 14 has a through hole 23 on its central axis, and the diameter of the hole is 1.2 to 2.2 compared to the diameter of the hole 8.
twice as big.

An elastic rubber sleeve 24 is fitted into this hole 23, for example with a preload, the hole 25 of which has a diameter that is equal to or smaller than the diameter of the hole 8.

Hole 25 is located coaxially with respect to the outer circumference of sleeve 24 .

In the case of an attached cutter blade, the hole 23 is positioned closer to the lateral slit 5 than the through hole 8 of the drill head 3 by a predetermined eccentric amount.
It is far from the bottom 6 of

The attached cutter blade 14 is held at its end by a pin 26 that is press-fitted into the hole 8 of the drill head 3, and the pin connects the hole 25 of the rubber sleeve 24 with the hole 8 of the rubber sleeve 24.
, so that the rubber sleeve 24 is passed through in a clamping manner in the direction of the bottom 6 of the transverse slit 5 .

The cutter blade 14 thereby cuts the bottom 6 of the horizontal slit 5.
is pressed elastically against the

After at least partial withdrawal of the pin 26, the cutter blade 14 can be withdrawn from the transverse slit 5, rotated or oriented about its axis, and mounted again and stopped with the pin 26, its As a result, the other cutting edge 16 of the cutter blade 14 forms a drill bit.

The axial dimensions of the rubber sleeve 24 are identical to the thickness of the cutter blade 14 in the illustrated embodiment, the rubber sleeve 24 being able to be glued to the cutter blade 14 .

As shown in FIG. 4, in the drill, the cutter blade 14 and the pin 26 are arranged in the shape of a cross at right angles to each other in the axial direction, the groove ends 9.degree. 10 being located opposite the diameter of this cross 2. At each corner, each side has a cutter blade 14
and located apart from the pin 26.

The diameter of pin 26 is only slightly smaller than the thickness of cutter blade 14.

In the embodiment shown in FIG. 5, groove ends 9a are provided at the four corners of the cross formed by the cutter blade 14a and the pin 26a.
10a are arranged diametrically symmetrically opposite each other with respect to a common axial plane of the drill or drill head 3a.

In the embodiment according to FIGS. 1 to 4, and in particular in the embodiment according to FIG. 5, two helical swarf grooves can be provided instead of one swarf groove.

The cutter blades 14b according to FIGS. 6 and 7 each have two
2 with two mutually angularly positioned cutting edges 16b.
It has only one blade 18b, the two blades 18b being arranged symmetrically opposite each other with respect to a common axial plane of the cutter blade 14b.

The side edge 27 of the cutter blade 14b, which is adjacent to the blade 18b and lies parallel to one another and is flat over the entire thickness of the cutter blade 14b, is shorter than the cutting edge 16b.

In the embodiment shown in FIGS. 8 to 10, the cutter blade 14c has only a single cutting edge 18c, so that the cutter blade 14C is not designed as a turning plate.

The horizontal slit 5C provided in the drill head 3c of the drill shank 1c is substantially flat and has a bottom 6C perpendicular to the drill axis, and the bottom has a rectangular shape that extends into the center of the horizontal slit 5. , the circular formation is provided with an oval centering recess 28 .

The cutter blade 14c has a centering projection 20 inserted into a centering recess 28 on the opposite edge of the blade 18G formed by two mutually angled cutting edges 16. Corresponding edges on both sides of the slit 20 are provided so as to touch the bottom 6c of the horizontal slit 5C.

A through hole 23C is provided in the cutter blade 14c, and the diameter of the hole is approximately the same as the diameter of the through hole 8C of the drill head 3c so that the pin 26c is directly press-fitted into the cutter blade 14c.

In this embodiment, the distance of pin 26C from the bottom 6c of slit 5c is smaller than the distance of pin 26c from blade 18c or cutting edge 19C.

The embodiment according to FIGS. 11 and 12 essentially differs from the embodiment according to FIGS. 8 to 10, i.e. the pin 26d in the form of a helical clamping pin is located parallel to the plane of the cutter blade 14d. , the cutter blade 14d has a groove 23d on its side surface 15d, while the transverse slot 5d likewise has a groove 8d on its side surface 7d.

The installed cutter blade 14d has grooves 23d and 8d.
forms a thank-through recess for the pin 26d, the depth of which is sufficient only for the guidance and retention of the pin 26d, which is formed by undercutting this groove and is press-fit into the hole. so that it is larger than the radius of pin 26.

The radius of curvature of the cross-section of the groove 23d in the cutter blade 14d is slightly larger than the radius of curvature of the cross-section of the pin 26b, with the longitudinal center plane of the groove 23d also being such that the pin 26d is spaced apart from the bottom of the transverse slit 5d. The cutter blade 14 contacts only the side surface of the groove 23d located under the preload.
d is a groove 8 so as to be pressed toward the bottom of the horizontal slit 5d.
It is located slightly further away from the bottom of the horizontal slit 5d compared to the longitudinal central plane of d.

As shown in FIGS. 11 and 12, in this embodiment the drill shank 1d has two lateral inclined surfaces 2d parallel to the axis and parallel to the cutter blade 14d instead of the chip groove.
The inclined surface extends over the entire length of the drill shank 1d and almost reaches the end of the drill head 3d.

The bottom surface 28e provided for the attachment of the cutter blade 14e, as shown in FIG. It is arranged in section 3e.

The insertion piece 29 is also flat and has a cutter blade 14e.
The thickness is approximately the same as that of .

The insertion piece 29 is arranged in the horizontal slit of the drill head 3e,
The transverse slit is therefore as deep as the height of the insertion piece 29.

The bottom surface of this transverse slit, which has flat side walls over its entire height, has an arc-shaped concave curve, the axis of the curve being located at a distance from the front of the drill head 3e, and the axes intersecting at right angles. , so that the bottom surface 6e can be milled in a simple manner.

The surface of the insert piece 29 which is in full contact with the bottom surface 6e of the transverse slit is correspondingly curved, so that the drill head 3e and the insert piece 29 are aligned with each other in the mounted cutter blade 14e.

The insert piece 29 can be fixed to the transverse slit by brazing, press-fitting, welding such as ultrasonic or electron beam welding or the like.

For reasons of finishing, a hole can also be provided in the center of the slot bottom provided for the attachment of the cutter blade.

However, this hole can be removed if the transverse slit is later pressed in.

The embodiment according to FIG. 13 makes it possible to prevent the slit bottom from being subjected to large forces.

[Brief explanation of drawings]

Fig. 1 is a partial view of a drill according to the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, Fig. 3 is a sectional view taken along the line I-I in Fig. 2, and Fig. 4 is a sectional view taken along the line I-I in Fig. 2. FIG. 1 is a plan view of the drill according to FIG. 1; FIG. 5 is a view corresponding to FIG. 4 of another embodiment of the drill; FIG.
7 is a view from the left of the blade portion according to FIG. 6; FIGS. 8 to 10 are views of another embodiment of the drill; FIGS. 11 is a diagram corresponding to FIG. 9 of another embodiment of the drill, FIG. 12 is a sectional view taken along the line ■-■ of FIG. 11, and FIG. 13 is a diagram of another embodiment of the drill. FIG. 2 is an example diagram. 1 or 1c or 1d...Drill shank, 5 or 5c or 5d...Horizontal slit, 14 or 14
a or 14b or 14c or 14d...Cutter, 8゜25 or gc, 23c or 8 a, 23
d--- recess, 26 or 26a or 26c or 26
d...Holding member.

Claims (1)

[Claims] 1 a drill shank, the drill shank having a transverse slit in the drill head for the accommodation of a plate-shaped cutter blade, the cutter blade having at least one projection in the direction of the drill bearing and being removably held in the drill head; The horizontal slit is partitioned in the drill axis direction by a bottom that faces transversely to the drill axis, and the drill shank is partitioned in the drill axis direction by a bottom that is oriented transversely to the drill axis. In those with a recess, the cutter blade 14 is located transversely to the drill axis and the cutter blade 14 and the hole 2 in the drill head 3
The pin 26 is removably held in the drill head 3 by at least one pin 26 passing through the pins 3 and 8.
is located in the circumferential envelope plane of the drill, the recess in the bottom 6 has a V-shaped cross section when viewed in the direction of the plate plane of the cutter blade 14, and the centering projection 20 of the cutter blade 14 has a V-shaped cross section at least at the edge. The centering protrusion 2
A rock drill characterized in that the V shadow line of 0 is in contact with the V-shaped portion of the recess, and the pin 26 exerts a clamping force on the cutter blade 14 in the direction of the recess.