JPH0651245B2 - Chip breaking punch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention mainly relates to a mechanism for shortly breaking narrow strip-like chips that are continuously generated when a relatively deep hole is drilled in a hard metal material such as a steel plate. The present invention relates to a chip breaking type perforating apparatus having a.

(Prior Art) A conventional punching device for a hard metal material is generally configured to rotate a punched body having a punching blade at a lower end and to perform a punching work while feeding the punched body at a constant speed in an axial direction. . For this reason, narrow strip-shaped chips are continuously generated, and the chips may wind around the shank portion or the like to hinder the drilling work, and both edges of the chips of the hard metal material are sharp. There was a risk of injury due to chips.

Therefore, a chip breaking type perforation in which the chips to be cut are appropriately shredded by intermittently projecting and retracting in the axial direction during rotation of the perforation body (drill) to bring the boring blade into and out of the cutting position. A device has been proposed. (For example,
On the other hand, a core-type perforated body is used as a device for perforating a relatively large diameter, and the center of the perforated body is used for positioning so that it can be moved backward while being biased by a spring. Some have a center pin.

In this type of device, when applying a mechanism that appropriately separates the chips by contacting and separating the drilling blade from the chip position as described above, the drilling blade is firmly positioned with the center pin strongly pressed against the surface of the drilled object. If the surface of the object to be drilled is not cut, the piercing blade may ditch on the surface of the object to be drilled and proper drilling may not be performed.

In other words, it is required to attach a strong spring that biases the center pin.

(Problems to be Solved by the Invention) However, as described above, when a strong spring is used to urge the center pin, the drilling work is always performed against the compression pressure of this strong spring. Therefore, the compression pressure of the spring acts so as to weaken the feed force applied in the axial direction, thereby deteriorating the workability.

Further, at the time of finishing the drilling, the cutting mass that remains in the hollowed-out shape in the drilling body may be inclined in the drilling body and caught by the drilling body and may not come out. When the compression pressure is applied, it is difficult to take out the cut mass from the perforated body.

The present invention has been made in view of the above points, at the start of drilling, a strong spring force is applied to the center pin to perform accurate positioning, and the spring force is weakened from the middle of drilling until the end of drilling. An object of the present invention is to provide a chip breaking type perforation device which improves workability and can easily take out a chip lump remaining in a perforated body.

(Means for Solving the Problems) A gist of the present invention for achieving the above-mentioned object is to provide a shank body having a shank at an upper portion and having a large diameter portion and a small diameter portion formed at a lower portion of the large diameter portion. A diameter of the shank body in an annular space formed between a sleeve-shaped fixed body rotatably mounted on the large-diameter portion of the shank body and a small-diameter portion of the shank body of the fixed body. A sleeve-shaped rotation transmission body that is disposed in the small portion, is movably engaged with the small diameter portion in the axial direction by a predetermined distance, and rotates integrally with the shank body; At least a taper surface held by an annular retainer, a plurality of balls rotating in contact with a tapered surface formed relative to the small diameter base portion of the shank body and the upper end portion of the rotation transmitting body, and rotating in contact with the inner circumferential surface of the fixed body; A plurality of ball fitting recesses formed on one side at equal intervals, A drilling blade is provided at the lower end, a through hole is provided at the center, and an upper end insertion portion is engaged and connected to a rotation transmitting body, and a through hole of the drilled body is communicated with the center of the shak body. A spring loading hole provided, a center pin that is inserted into the insertion hole of the perforated body so as to be able to move backward, and has a tip protruding downward from the perforation body, and a center pin that is loaded into the spring loading hole and biases the center pin in the protruding direction. It is equipped with a spring that positions the center pin against the surface of the object to be drilled and rotates the drill body integrally with the shank body, and intermittently projects and retracts in the axial direction to cut with the drilling blade of the drill body. In the case where the chips to be cut are appropriately cut, the spring loading hole is formed with an intermediate step, the upper end of the center pin is projected into the spring loading hole, and a spring force is applied between the upper end of the setter pin and the bottom of the spring loading hole. weak A small-diameter first spring is loaded, an engagement groove is provided around the upper surface of the center pin, and a locking ball that locks in the engagement groove is provided and locked on the locking ball. And a receiving seat that moves in the spring loading hole is provided, and a large-diameter second spring having a strong spring force is loaded between the receiving seat and the spring loading hole, and an annular groove is formed on the inner peripheral surface of the spring loading hole. The chip breaking perforation apparatus is characterized in that the center pin is released from the bias of the second spring by retracting the locking ball in the annular groove during the compression process of the second spring.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall sectional view of the punching device, and FIG. 2 is II- of FIG.
II line enlarged sectional view, FIG. 3 is a III-III line sectional view of FIG.
4 is a sectional view taken along line IV-IV in FIG. 2, and FIG. 5 is V in FIG.
FIG.

In FIGS. 1 and 2, 1 is a shank body having a shank 1a at its upper end, and a large diameter portion 1b and a small diameter portion 1e are continuously formed on the outer peripheral surface of the shank body 1 at the lower portion of the large diameter portion 1b. Is forming. Further, the shank body 1 is provided with a spring loading hole 1c having an intermediate step and having a lower end opened at the center thereof.

A sleeve-shaped fixed body 4 is rotatably mounted on the large-diameter portion 1b, and a sleeve-shaped rotation transmission body 2 is mounted on the small-diameter portion 1e.
This rotation transmitting body 2 is connected to the small diameter portion 1e through a submerged key type key 3 (see FIG. 5) fitted in a key hole 2a provided in the rotation transmitting 2 and rotates integrally with the shank body 1. In addition, it is movable in the axial direction within a certain range.

In the annular space formed between the fixed body 4 and the small diameter portion, at the base of the small diameter portion 1e and the upper end of the rotation transmission body 2, the tapered surfaces 1f and 2b are relatively opposed and reduced in diameter. Are formed on the taper surface 2b on the rotation transmission body 2 side (four in this embodiment).
The ball fitting recesses 2c are formed at equal intervals.

The same number of balls (steel balls) for feeding force as the number of the recesses 2c are arranged so as to come into contact with the taper surfaces 1f and 2b and three points on the inner peripheral surface of the fixed body 4 so as to be rotatable. As shown in FIG. 4, they are rotatably held at equal intervals by an annular retainer 5a.

In addition, 1g is a retaining ring of the fixed body 4 provided on the shank body 1, 2e is a retaining ring of the fixed body 4 provided on the rotation transmission body 2, and 4a is interposed between the fixed body 4 and the rotation transmission body 2. It is a bearing bush.

On the inner peripheral surface of the rotation transmitting body 2, engaging elements 2d for transmitting rotation to a perforated body 6 which will be described later are provided at three locations as shown in FIG.

The perforated body 6 is a core type having a perforation blade on the lower end periphery,
An insertion portion 6a is provided at the upper end, and the insertion portion 6a is used as the rotation transmission member.
The protrusion 6b provided at the end of the insertion portion 6a by being inserted into the lower end opening of 2 is engaged with the engaging element 2d of the rotation transmitting body 2. In addition,
In the engagement between the protrusion 6b and the engaging element 2d, the protrusion 6b is movable in the axial direction within a certain range.

Further, an annular groove 6c into which a ball 7 described later is fitted is provided on the intermediate outer peripheral surface of the insertion portion 6a of the perforated body 6, and a plurality of accommodation holes 2g are formed in the lower portion of the rotation transmission body 2 corresponding to the annular groove 6c. Through the
A ball 7 attached to the perforated body 6 is loaded into the accommodation hole 2g, and an extrusion operation sleeve 7a for the ball 7 is axially movably disposed around the accommodation hole 2g and is urged downward by a spring 7b.
The perforated body 6 is detachable from the rotation transmission body 2.
Incidentally, 7c is a retaining ring for the sleeve 7a provided on the rotation transmitting body 2.

The center pin 8 for positioning the hole is inserted into the insertion hole 6d penetrating the center of the hole 6 so that the center pin 8
Extend the tip of the
The upper end of 8 is projected into the spring loading hole 1c.

A small diameter first spring 9a having a weak spring force is loaded between the locking step 8b provided at the upper end of the center pin 8 and the spring loading hole bottom 1d to urge the center pin 8 in the protruding direction.

Further, an engaging groove 8c is provided around the upper end peripheral surface of the center pin 8, a plurality of engaging balls 9c for engaging with the engaging groove 8c are provided, and the engaging ball 9c is provided. A receiving seat 9d that locks and moves in the spring loading hole 1c is provided, and a large-diameter second spring 9b having a strong spring force is loaded between the receiving seat 9d and the spring loading hole 1c to form a receiving seat 9d. And locking balls
Center pin 8 is biased in the protruding direction via 9c.

An annular groove 1h is formed around the spring loading hole.
In this annular groove 1h, the center pin 8 is retracted into the spring loading hole 1c, and the locking ball 9c is retracted during the compression process of the second spring 9b to move the center pin 8 to the second spring 9b.
It is to release from the bias of.

Note that 9e is a retaining ring provided at the end of the spring loading hole 1c for retaining the locking ball 9c.

Further, 10 is an oil supply hole, which penetrates the peripheral walls of the fixed body 4 and the shank body 1 to communicate with the spring loading hole 1e, and is connected to an external oil supply mechanism (not shown). It is a thing.

Next, the operation of the above embodiment will be described.

In FIG. 1, the shank 1a of the shank body 1 is mounted on a drilling machine, such as a drilling machine or a drill, which can be rotated and drilled and fed, for use.

In this drilling, first, the tip of the center pin 8 is pressed against the drilling center of the surface of the object to be drilled, and the first spring 9a
And, the perforation feed is applied against the bias of the second spring 9b to cause the perforation blade to cut into the surface of the object to be perforated.

Here, the rotational force transmitted from the punch to the shank body 1 is transmitted from the rotation transmitting body 2 to the punch body 6 via the key 3. The axial drilling feed force transmitted from the drilling machine to the shank body 1 is also transmitted from the rotation transmitting body 2 to the drilling body 6 via the balls 5.

By the way, when the shank body 1 and the rotation transmitting body 2 are integrally rotated at the same number of revolutions, the respective balls 5 for transmitting the feed force come into contact with the inner peripheral surface of the fixed body 4, so that as shown in FIG. , While rotating in the opposite direction to the shank body 1 and the rotation transmitting body 2, revolves in the same direction as the shank body 1 and the rotation transmitting body 2 together with the annular retainer 5a, but contacts the ball 5 from the rotation center axis of the shank body 1. The distance to the tapered surface 1f, 2b is the ball
Since it is larger than the radius of 5, the revolution angular velocity of the ball 5 becomes slower than the revolution angular velocity of the shank body 1 or the rotation transmitting body 2. Therefore, a difference occurs between the rotation angular velocity of the shank body 1 or the rotation transmitting body 2 and the revolution angular velocity of each ball 5, and each ball 5 is intermittently fitted into the recess 2c of the tapered surface 2b on the rotation transmitting body 2 side. Become.

In this way, the perforated body 6 becomes temporarily free (in a state in which it can descend) in the axial direction (direction in which the feed force acts) with respect to the shank body 1 and from the shank body 1 to the perforated body 6 via the rotation transmission body 2. The transmission of the feeding force is temporarily interrupted, and the chips continuously cut by the boring blade of the boring body 6 are cut into short pieces.

In this punching device, the punching blade cuts into the surface of the object to be punched while the punching body 6 moves up and down (projects / retracts) in the axial direction in order to cut chips during the drilling work. At the start of drilling, the two spring forces of the first spring 9a and the second spring 9b act on the center pin 8 at the same time to strongly press against the surface of the object to be drilled to determine the position. When making a cut with respect to the surface of the object to be punched, the punching blade does not move on the surface of the object to be punched to cause a positional shift, and the cutting can be reliably performed at a predetermined position.

Then, the drilling continues while the center pin 8 retracts toward the spring loading hole 1c side and compresses the first spring 9a and the second spring 9b, and when the locking ball 9c reaches the annular groove 1h part, the locking is performed. The ball 9c retreats into the annular groove 1h to release the center pin 8 from the bias of the second spring 9b, and thereafter, the drilling is continued under the bias of only the first spring 9a and the drilling is completed.

After the boring work is completed, a hollow cutting mass remains in the boring body 6. This cutting mass is normally pushed out by the compression pressure of the first spring 9a at the end of drilling,
6 There are things that do not come out because they are caught in the inside, such as tilting. Such a cut mass is taken out by appropriately moving it from the outside to eliminate the catch. Here, since the spring force of the first spring 9a is weak to move the cut mass caught in the punched body 6, it can be freely moved and easily taken out.

(Effects of the Invention) The punching device of the present invention described above has the following effects.

(1) During the drilling work, the drilling body intermittently moves up and down in the axial direction to cut the chips, but at the start of drilling on the surface of the object to be drilled, two spring forces are simultaneously applied to the center pin and pressed strongly. In order to position the center of the perforation, the perforation blade does not move on the surface of the perforated object when the perforation blade cuts into the surface of the perforated object.
A reliable and smooth perforation can be performed.

(2) During drilling, the center pin is automatically released from the biasing force of the second spring, which has a strong spring force, which makes it easier to apply the feed force after drilling. The cut mass that does not come out due to being caught can be easily removed by moving it from the outside, improving workability.

[Brief description of drawings]

1 is an overall sectional view showing an embodiment of a punching device of the present invention, FIG. 2 is an enlarged sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2, and FIG. 5 is a view taken along the line VV in FIG. 1 …… Shank body, 1a …… Shank, 1b …… Large diameter part, 1c
...... Spring loading hole, 1e ...... Small diameter part, 1h ... Annular groove,
2 ...... Rotation transmission body, 4 ...... Fixed body, 6 ...... Perforated body, 8 ...
… Center pin, 8c… Engagement groove, 9a… First spring, 9b… Second spring, 9c… Locking ball.

Claims (1)

[Claims] 1. A shank body having a shank on an upper portion and a large diameter portion and a small diameter portion formed on a lower portion of the large diameter portion, and a sleeve-like fixed body rotatably mounted on the large diameter portion of the shank body. And a small space of the shank body in an annular space formed between the fixed body and the small diameter part of the shank body, and moves a predetermined distance in the axial direction with respect to the small diameter part. A sleeve-shaped rotation transmission body that freely engages and rotates integrally with the shank body, and is held by an annular retainer in the annular space,
A tapered surface formed relative to the small diameter base portion of the shank body and an upper end portion of the rotation transmitting body, a plurality of balls rotating in contact with the peripheral surface of the fixed body, and formed at equal intervals on at least one of the tapered surfaces. A plurality of ball-fitting recesses, a drilling blade at the lower end, a through-hole penetrating the center, and an upper-end insertion portion engaged and connected to a rotation transmitting body; and a through-hole for the drilling body. A spring-loading hole provided in the center of the shank body so as to communicate with the center hole, a center pin having a tip projecting downwardly through the through-hole of the perforation body, and a tip protruding downward from the perforation body, and the spring-loading hole. Equipped with a spring that biases the center pin in the projecting direction, the center pin positions the surface of the object to be drilled by the center pin, and the boring body rotates integrally with the shank body while intermittently projecting and retracting in the axial direction. Drilling blade for drilling body In a device for appropriately cutting chips to be cut, the spring loading hole is formed with an intermediate step, the upper end of the center pin is projected into the spring loading hole, and a spring is provided between the upper end of the center pin and the bottom of the spring loading hole. A small diameter first spring having a weak force is loaded, an engaging groove is provided around the upper surface of the center pin, and an engaging ball that engages with the engaging groove is provided. A receiving seat that moves in the spring loading hole by being locked to the spring is provided, and a large-diameter second spring having a strong spring force is loaded between the receiving seat and the spring loading hole. A chip breaking type perforating device, characterized in that an annular groove is provided, and the locking ball is retracted in the annular groove during the compression process of the second spring to release the center pin from the bias of the second spring.