JPH0679510A - Core drill - Google Patents

Abstract

PURPOSE:To efficiently and smoothly bore a plurality of large diameter holes identical each in diameter by providing an extruding sleeve which automatically goes in and out within a core body so as to allow waste material such as cutting chips remaining within the core body to be extruded after the core body has been bored. CONSTITUTION:When the boring blade 14 of a core body 13 has bored a bored member while being thrusted through the member, a motive plate 18 is brought into contact with the surface of a bored member with pressure, so that the rotation of an outer cylinder 17 and its movement toward the boring direction are suspended. The spline connection of the upper end section of an inner cylinder 8 to a base body 1 is released, so that the rotation of the inner cylinder 8 is thereby suspended. Simultaneously, the rotation of the extrusion sleeve 7 is also suspended, and the base body 1 is brought into idle rotation with respect to the extrusion sleeve 7. The idle rotation permits an engaging pin 36 to be moved to the inside of a screw groove 34 of the base body 1, the extrusion sleeve 7 is lowered down against a pull-up spring 15 so as to be projected out in the inside of the core body 13, so that waste material such as cutting chips remaining in the inside of the core body 13 is extruded out of the core body 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core drill used for drilling relatively large diameter holes.

[0002]

2. Description of the Related Art Conventionally, a core drill with a center drill has been put into practical use as a core drill for drilling a relatively large diameter hole in an object to be drilled.

For the drilling of an object to be drilled by this type of core drill, a center hole is preceded by a center hole, and the core hole is used as a guide to cut the drilling blade of the core body into the object to be drilled to drill a large-diameter hole. However, when drilling is completed, a disk-shaped cut-out waste material is left in the core body with a center drill piercing the center hole.

In this case, since the center hole of the cut waste material is substantially equal to the center drill diameter and the outer diameter of the waste material is substantially equal to the inner diameter of the core body, even if the drilling is performed downward, it is caught in the core body after the drilling. However, it may not come out easily and hinder the progress of the drilling work.

Therefore, in order to positively take out the cut-out waste material from the core body at the time when the boring work is completed, the core body is attached to the lower end of the base body having the shank, and the core body is opened to form an intermediate hole in the base body. A support rod is slidably fitted in the bore for a predetermined length in the axial direction so as to be vertically movable, and is urged downward by a push-down spring, and a rod-shaped stopper body is fixed to the lower end of the support rod. A center drill is attached to the lower end of the stopper body, and when the center hole is drilled by the center drill, the stopper body is pushed up against the pressing spring to press the upper end surface of the stopper body against the lower surface of the base body to receive the drilling pressure,
The present applicant has previously proposed a core drill having a structure in which a stopper body is advanced by the spring force of a push-down spring to push out a cut-out waste material from the core body when drilling by the core body is completed.

[0006]

In the drilling by the core drill having the above-mentioned structure, since the pressing spring is compressed, the drilling thrust is not changed.
For example, it can be used for perforating a metal plate or the like, but a cut-out waste material having a relatively thick thickness may be caught in the core body after the perforation and cannot be executed.

The present invention has been made in view of the above points, and enables a large-diameter hole to be drilled in a relatively thick object to be drilled, and a core drill that automatically pushes out the cut waste material remaining in the core body after drilling. The purpose is to provide.

[0008]

SUMMARY OF THE INVENTION To achieve the above object, the gist of the present invention is to provide a base body having a shank at the upper end and a center drill attached at the lower end, and rotating, vertically moving on the base body. A push-out sleeve slidably fitted and urged upward by a pull-up spring, and a push-up sleeve slidably fitted on the push-out sleeve, the upper end of which is spline-engaged with the base body in a disengageable manner, and the core body is attached to the lower end. The attached inner cylinder, the outer cylinder slidably fitted on the inner cylinder so as to be vertically movable, and urged downward by a pressing spring, and the outer cylinder provided in association with the outer cylinder. An outer cylinder movement restricting mechanism that gives a relative position movement to the inner cylinder, a ball holding member above the pushing sleeve and fixed to the base body, and a ball holding member held by the inner cylinder and selective to the ball holding member and the outer cylinder. A thrust transmission ball that engages and disengages with The inner cylinder connecting ball held by the ball holding member and engaged with and disengaged from the inner cylinder is slidably fitted on the base body so as to be vertically movable, and is urged downward by a pressing spring to engage the inner cylinder connecting ball. A ball pushing sleeve that holds the mating position and the disengaging position, a screw groove that is provided on the peripheral surface of the base body and has rounded up portions at the upper and lower ends, and a member that is attached to the upper portion of the pushing sleeve and that is engaged with and disengaged from the screw groove A core drill comprising a dowel pin, a pin holding member that holds the engaging pin at an engaging position and a disengaging position, and a leaf spring that is formed in the inner cylinder and presses the engaging pin inward. It is in.

[0009]

Operation The perforation of the object to be perforated is carried out by integrally rotating the center drill and the core body while keeping the positional relationship constant.

When the movement of the outer cylinder is stopped by the outer cylinder movement restricting mechanism at the time of finishing the perforation, the pushing sleeve projects into the core body in association with the outer cylinder and pushes out the cut waste material remaining in the core body, Return to the original state.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 is a base, which is in the shape of a round bar, has a shank 2 supported by a chuck of a drive shaft at the upper portion, and has a center drill 3 attached at the lower end.
The center drill 3 has a well-known structure in which a drilling blade 4 is provided at the lower end and a spiral groove 5 for chip discharge is engraved on the outer peripheral surface.In the embodiment, the center drill is provided in a mounting hole provided under the base body 1. The base of 3 is inserted and fixed with the set screw 6.

Reference numeral 7 denotes an extruding sleeve slidably fitted on the base body 1 so as to be rotatable and vertically movable. Reference numeral 8 denotes an inner cylinder slidably fitted on the extruding sleeve 7 so that the inner cylinder 8 has a spline portion 9 at its upper end. Is provided, and is spline-coupled to the spline portion 10 provided on the base body 1 in a disengageable manner. Further, a rotation stopping pin 11 is provided on a large diameter portion formed at the upper end portion of the pushing sleeve 7, and this is engaged with a long hole 12 bored in the inner cylinder 8 in the axial direction so as to be vertically slidable. There is.

Reference numeral 13 denotes a core body attached to the lower end of the inner cylinder 8. The core body 13 has a well-known structure in which a perforating blade 14 is provided on the peripheral edge of the lower end opening. Are connected.

Reference numeral 15 is a pull-up spring which is interposed between the inner cylinder 8 and the pushing sleeve 7 and biases the pushing sleeve 7 upward, and the lower end of which is a receiving member 16 provided on the lower end peripheral surface of the inner barrel 8.
The upper end is received by the lower surface of the large diameter portion of the extrusion sleeve 7.

Reference numeral 17 denotes an outer cylinder slidably fitted on the inner cylinder 8 and 18 denotes an outer cylinder operation restricting mechanism provided in association with the outer cylinder 17, and the outer cylinder operation restricting mechanism 18 is an outer cylinder 17 To stop the rotation of and to give relative position movement to both with respect to the inner cylinder 8,
In the embodiment, the starting plate is fixed to the lower end of the outer cylinder, and the starting plate is attached to the upper surface of the core body 13 and projects outward from the core body 13.

Reference numeral 19 denotes an outer sleeve above the outer cylinder 17 and rotatably mounted on the base body 1, and 20 is interposed between the outer sleeve 19 and the outer cylinder 17 to urge the outer cylinder 17 downward. A push-down spring receives the upper end on the upper wall surface of the jacket sleeve 19 and the lower end on the upper end surface of the outer cylinder 17.

Numeral 22 is above the extrusion sleeve 7 and is located on the base body 1.
Ball holding member fixed to the inner cylinder 8 is a hole provided in the upper part of the inner cylinder 8.
The thrust-transmitting balls held by 23, a part of which protrudes from the inner cylinder 8 and is provided on the surface of the ball holding member 22 and the outer cylinder 17
It is selectively engaged with and disengaged from the recess 25 provided on the inner surface.

Reference numeral 26 denotes an inner cylinder coupling ball held in a hole 27 provided in the ball holding member 22, a part of which is the ball holding member 22.
Numeral 29 that projects from and is engaged with and disengaged from the recess 28 provided on the inner surface of the inner cylinder 8 is slidably fitted on the base body 1 inside the ball holding member 22 so as to be vertically movable, and the inner cylinder coupling ball 26 is set at the engaging position. With a ball pushing sleeve that holds it in the disengaged position,
And a stepped peripheral surface composed of a small diameter peripheral surface portion 31 and a tapered peripheral surface portion 32.

Reference numeral 33 denotes a push-down spring which is interposed between the ball holding member 22 and the ball pushing sleeve 29 and biases the ball pushing sleeve 29 downward, and a step portion whose upper end is formed inside the ball holding member 22. The lower end is received by the upper end surface of the ball pushing sleeve 29.

Reference numeral 34 designates a thread groove formed on the peripheral surface of the base body 1 and having rounded-up portions 35 formed at the upper and lower ends thereof. 36 is an engagement pin which is mounted on the large diameter portion of the pushing sleeve 7 and engages and disengages with the thread groove 34. Reference numeral 37 is a pin holding member that holds the engaging pin 36 in the engaged position where the engaging pin 36 is engaged with the thread groove 34 and the disengaged position, and is made of an elastic ring in the embodiment, and the head of the engaging pin 36 formed into a round shape at the engaging position. It is pressed against the surface of the member and pressed inward, and at the disengaged position, it is fitted into the circumferential groove 38 provided in the head base of the engaging pin 36.

Reference numeral 39 denotes a leaf spring which is formed on the upper portion of the inner cylinder 8 and presses the engaging pin 36 inwardly at the upper portion of the screw groove 34. In the embodiment, the leaf spring is cut and raised from the inner cylinder 8 and the upper end is the engaging pin. It is designed to be pressed against the head surface of 36.

Reference numeral 40 in the drawing denotes a rotation preventing key interposed between the inner cylinder 8 and the outer cylinder 17, and is engaged with a long groove 41 provided in the lower part of the outer cylinder 17 in the axial direction so as to be vertically slidable. ing.

Further, as the above-mentioned outer cylinder operation restricting mechanism 18, in addition to a starting plate fixedly provided at the lower end of the outer cylinder, an outer cylinder operation restricting sleeve is fitted onto the outer cylinder so as to rotate freely, and A friction ring may be interposed between the outer cylinder movement restricting sleeves, and the outer cylinder movement restricting sleeve may be pulled up to stop the rotation of the outer cylinder to give relative position movement to the inner cylinder.

With respect to the core drill constructed as described above, the drilling work procedure will be described with reference to FIGS.

In the normal position, the upper end of the inner cylinder 8 is spline-coupled to the base body 1, and the thrust transmitting balls 21 held by the inner cylinder 8 are engaged with the recesses 24 of the ball holding member 22. The reference numeral 26 corresponds to the small-diameter peripheral surface portion 31 of the ball pushing sleeve 29 in the raised position, and is pulled out from the recess 28 of the inner cylinder 8.

The shank 2 is used to punch the plate A to be punched.
The driving force (rotational force and drilling thrust) from the side to the center drill 3 is directly transmitted through the base body 1. Core body
Rotational force for 13 is applied from the spline portion 10 of the base 1 to the inner cylinder.
The perforation thrust is transmitted from the ball holding member 22 through the thrust transmission balls 21 and the inner cylinder 8. (See FIG. 3) At the time when the punching blade 14 of the core body 13 penetrates the object A to be drilled and finishes the drilling, the starting plate 18 (outer cylinder operation restricting mechanism) is pressed against the surface A of the object to be punched, The rotation and movement of the cylinder 17 in the drilling direction stop. Here, the outer cylinder 17 moves in the axial direction relative to the base body 1 against the push-down spring 20, and the thrust transmission balls 21 engage with the recesses 25 on the inner surface of the outer cylinder 17 for thrust transmission. Ball holding member 22 by ball 21 and inner cylinder
Release the engagement relationship with 8. Continue to the inner cylinder 8 upper end and base
The spline connection with 1 is released and the inner cylinder 8 stops rotating. At this time, the inner cylinder engaging balls 26 are not
In response to this, the pressing spring 33 lowers the ball pushing sleeve 29, and the inner cylinder engaging ball 26 is pushed by the large-diameter peripheral surface portion 30 and engages with the recess 28. The lower portion of the ball holding member 29 projects below the ball holding member 22.

The rotation of the inner cylinder 8 is stopped and the pushing sleeve 7
Also stops rotating, and the substrate 1 idles with respect to the pushing sleeve 7. Due to this idling, the engaging pin 36 is screwed into the thread groove 34 of the base 1.
It moves inward and lowers the pushing sleeve 7 against the pulling spring 15 so as to project into the core body 13 and push out the cut-out waste material A ′ remaining in the core body 13 from the core body 13. (See FIG. 4) The engagement pin 36 reaches the lower cut-up portion 35 of the thread groove 34, the engagement pin 36 is pushed out of the thread groove 34, and the engagement with the thread groove 34 is released. Here, the engagement pin 36 is held at the disengaged position by the pin holding member 37, and at the same time, the pushing sleeve 7 is pulled up by the spring force (accumulation) of the pulling spring 15. When the push-out sleeve 7 is pulled up, the engagement pin 36 exceeds the upper cut-up portion 35 of the thread groove 34, and the upper end surface of the push-out sleeve 7 abuts against the ball pushing sleeve 29 to push it up. By pushing up the ball pushing sleeve 29, the inner cylinder engaging ball 26 engaged with the concave portion 28 of the inner cylinder 8 is released from the constraint and is allowed to move freely. At the same time, the upper end of the leaf spring 39 is pressed against the head of the engaging pin 36 to press the engaging pin 36 inward. (Refer to Fig. 5) When drilling is completed and the base body 1 is lifted by the operation of pulling out the core drill from the object to be drilled A, the upper end of the inner cylinder 8 and the base body 1 are spline-coupled in the reverse order of the above operation, and the thrust transmitting balls are 21 engages with the recessed portion 24 of the ball holding member 22, the inner cylinder engaging ball 26 comes out of the recessed portion 28 of the inner cylinder 8, and the engagement pin 36 engages with the thread groove 34 by pressing by the leaf spring 39. To return to the normal position before drilling (initial state).

[0029]

According to the present invention configured as described above, the following effects can be obtained.

(A) Since the positional relationship between the center drill and the core body is fixed at the time of drilling and there is no difference from the viewpoint of driving force transmission, a general-purpose integrated core drill (core drill in which the center drill and the core body are integrated) is used. Perforation under the same conditions is possible, and it can be used for all kinds of perforation work regardless of the type of object to be perforated.

(B) When the punching by the core body is completed, the pushing sleeve automatically projects into and out of the core body and pushes out the cut-out waste material remaining in the core body, so that a large number of large-diameter holes are drilled. Work can be performed efficiently and smoothly.

(C) Since the stroke length of the pushing sleeve protruding and retracting in the core body can be set by the screw groove provided in the base body, it is convenient for punching a relatively thick object to be punched.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a core drill of the present invention.

FIG. 2 is a vertical cross-sectional view of a core drill main part.

FIG. 3 is an explanatory diagram of a drilling work procedure.

FIG. 4 is an explanatory diagram of a drilling work procedure.

FIG. 5 is an explanatory diagram of a drilling work procedure.

[Explanation of symbols]

 1 ... Base 3 ... Center drill 7 ... Push-out sleeve 8 ... Inner cylinder 17 ... Outer cylinder 18 ... Outer cylinder movement control mechanism 21 ... Thrust transmitting ball 22 ... Ball holding member 26 ... Inner cylinder engaging ball 29 ... Ball pushing sleeve 34 ... Screw groove 36 ... Engaging pin 37 ... Pin holding member 39 ... Leaf spring

Claims (1)

[Claims] 1. A base body having a shank at the upper end and a center drill attached at the lower end, an extrusion sleeve slidably fitted on the base body so as to be rotatable and vertically movable, and urged upward by a pulling spring, and the extrusion body. It is slidably fitted vertically on the sleeve, the upper end is splined to the base body so that it can be engaged and disengaged, and the inner cylinder with the core body attached to the lower end is slidably fitted vertically on the inner cylinder and pushed down. An outer cylinder urged downward by a spring, an outer cylinder operation restricting mechanism provided in association with the outer cylinder to stop rotation of the outer cylinder and move the relative position relative to the inner cylinder, and the outer cylinder. A jacket sleeve that is above and rotatably mounted on the base body, a ball holding member that is above the pushing sleeve and is fixed to the base body, and a ball holding member that is held by the inner cylinder and selectively engages the ball holding member and the outer cylinder. The thrust transmission ball to be released and the ball An inner cylinder coupling ball held by a holding member and engaged with and disengaged from the inner cylinder is slidably fitted on the base body so as to be vertically movable, and is urged downward by a push-down spring to engage the inner cylinder coupling ball. And a ball pushing sleeve held in the disengagement position, a thread groove formed on the peripheral surface of the base body and having rounded-up portions at the upper end and the lower end, and an engagement pin fitted to the upper portion of the pushing sleeve and engaged with and disengaged from the thread groove. A core drill comprising: a pin holding member that holds the engagement pin at an engagement position and a disengagement position; and a leaf spring that is formed on the inner cylinder and presses the engagement pin inward.