JP3436796B2 - Tapping drilling machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tapping drilling machine capable of drilling a workpiece with a drill and tapping a female thread with a tap. Regarding

[0002]

2. Description of the Related Art A conventional tapping drilling machine has a spindle directly or indirectly connected to a drive shaft of a spindle rotating motor, and a cutting edge tool such as a tap or a drill is mounted through a collet chuck or a universal chuck. The structure is such that the spindle is moved up and down by the drive of the feed motor. When tapping is performed with a tap, the attachment with the tap attached to the tip is set on the spindle, and mechanical play between the spindle rotation motor and the feed motor is performed by the axial play incorporated in the attachment. I was trying to absorb the error. Further, in the case of drilling, the tapping attachment is removed from the spindle and replaced with a drill attachment.

[0003]

In the conventional tapping drilling machine, it is necessary to replace the cutting edge tool together with the attachment when shifting from tapping to drilling and from drilling to tapping. However, since the work is large and inefficient, and the heavy attachment may be dropped during replacement, there is a very high risk of damaging the cutting edge tool. In addition, since the risk of foreign matter entering the joint (head) of the attachment and the spindle increases, there is a possibility that attachment of the cutting edge tool may be incomplete due to the attachment.

The present invention has been made in view of the above, and an object thereof is to provide a tapping drilling machine in which switching between drilling and tapping can be performed only by exchanging a cutting edge tool.

[0005]

To achieve the above object, the present invention provides a spindle divided into an input shaft and an output shaft, and an output shaft slidable in the axial direction with respect to the input shaft, In addition, a shaft connecting means for integrally connecting in the rotational direction, a biasing means such as a coil spring forming an axial clearance between the shaft ends of the input shaft and the output shaft, and a centrifugal generated by the rotation of the spindle. The force is converted into an axial force, and the force is used to move the output shaft to the input shaft side. The idle clearance in the compression direction is set to "0" under the condition that the spindle is in the high-speed rotation range necessary for drilling. Centrifugal force converting means to
Provided is a tapping drilling machine comprising centering means for aligning the shaft centers of an input shaft and an output shaft in a state where a floating clearance "0" is formed by joining the shaft ends of the input shaft and the output shaft.

Further, it is preferable that an axial clearance provided between the shaft ends of the input shaft and the output shaft is made to correspond to a bidirectional force of compression and tension.

[0007]

[Operation] When drilling, the spindle is rotated at high speed. The centrifugal force associated with the high speed rotation is converted into a force in the axial direction by the centrifugal force converting means, and the floating clearance in the compression direction between the input shaft and the output shaft is set to "0". When the shaft ends of the input shaft and the output shaft are joined together, the centering means works to fix the shafts of both shafts in a matched state, so that accurate drilling can be performed.
On the other hand, when tapping is performed, the spindle is rotated at low speed. Therefore, since the centrifugal force associated with the rotation is small, the centrifugal force converting means does not substantially function, and the floating gap between the input shaft and the output shaft formed by the urging means works effectively.
The spindle reacts and follows the force applied to the tap. In this way, the punching state and the tapping state are automatically switched according to the rotation speed of the spindle.

Further, the force applied to the taps is opposite immediately after the tapping is started and after the tapping is on the orbit, so that the floating gap between the input shaft and the output shaft is compressed. If you set both directions of and pulling, you can control the movement of the tap to the best condition.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a vertical cross-sectional view of a main part showing a tapped state, FIG. 2 is a vertical cross-sectional view of a main part showing a drilled state,
3 is an exploded perspective view of a main part shown by cutting away a part thereof, and FIG. 4 is a sectional view taken along the line YY of FIG.

The tapping drilling machine has a spindle 1 directly or indirectly connected to a drive shaft of a spindle rotating motor, and a tip of the spindle 1 is provided with a cutting edge tool such as a tap or a drill such as a collet chuck or a universal chuck. It has a known structure in which the spindle 1 is moved up and down by driving a feed motor.

The spindle 1 is shown in FIGS.
As shown in FIG. 2, the upper input shaft 1A and the lower output shaft 1B are divided. The input shaft 1A is connected to the spindle rotating motor, and the output shaft 1B has a cutting edge tool such as a drill or a tap attached to the lower end via a collet chuck. At the lower end of the input shaft 1A, an outer cup 2 formed by integrally connecting a lid plate 2b provided with a tapered cylinder 2a for inserting the input shaft and a bowl-shaped cup body 2c opening upward is fixedly fitted. Has been done. On the other hand, an inner cup 3 which is built in the outer cup 2 of the input shaft 1A and has a shaft fixing cylinder 3a protruding from the center is fixed to the upper end of the output shaft 1B. The output shaft 1B is different from the input shaft 1A by a spline 4a, which is a shaft connecting means 4 provided on the inner peripheral surface of the outer cup 2 and the outer peripheral surface of the inner cup 3,
They are connected so as to be slidable in the axial direction and integrated in the rotational direction.

The outer cup 2 of the input shaft 1A and the inner cup 3 of the output shaft 1B are connected to each other by a coil spring 5a which is a biasing means 5 whose both ends are locked to the taper cylinder 2a and the shaft fixing cylinder 3a. In the free state where the coil spring 5a is extended, a floating clearance 6C in the compression direction is provided between the shaft ends of the input shaft 1A and the output shaft 1B (between the inner surface of the lid plate 2b of the outer cup 2 and the upper end surface 3b of the inner cup 3). It is formed. Further, the inner cup 3 is suspended by a coil spring 5a, and a floating clearance 6E in the pulling direction is also formed between the inner cup 3 and a steel ball 7a of a centrifugal force converting means 7 described later.

A centrifugal force converting means 7 is provided between the outer cup 2 of the input shaft 1A and the inner cup 3 of the output shaft 1B.
As shown in FIGS. 3 and 4, six steel balls 7a, which are the core, are arranged at equal intervals. The moving direction of the steel ball 7a is restricted by the guide groove 7b provided on the inner surface of the outer cup 2. Since the bottom surface of the outer cup 2 is curved in an arc shape and draws a rising curve from the center to the outside, when the steel ball 7a receives a centrifugal force, it rises while rolling along the curved surface of the outer cup 2. In this way, the inner cup 3 is pushed up by the centrifugal force converted into the force in the axial direction, and rises straight toward the lid plate 2b of the outer cup 2.

Furthermore, centering means 8 is formed on the inner surface of the lid 2b of the outer cup 2 of the input shaft 1A and the upper end surface 3b of the inner cup 3 of the output shaft 1B. The centering means 8 is a V-shaped groove 8 provided in a circular shape on the inner surface of the lid plate 2b.
It is a combination of a and a circular mountain-shaped rib 8b provided in a circular shape on the upper end surface 3b of the inner cup 3, and a floating gap 6C "0" in which the shaft ends of the input shaft 1A and the output shaft 1B are joined together.
In this state, the V-groove 8a is fitted into the chevron rib 8b, and both shafts 1
The axes of A and 1B are aligned.

Next, the operation of the tapping drilling machine of the present invention will be described. First, when a drill is attached to the tip of the output shaft 1B for drilling, the spindle 1 is rotated at high speed. Then, due to the centrifugal force due to the high speed rotation, the steel ball 7
a rises along the curved surface of the outer cup 2, and the force causes the inner cup 3 to move upward until the upper end surface 3b is joined to the lid plate 2b of the outer cup 2. Then, the floating clearance 6C becomes "0", and the V-groove 8a and the chevron rib 8b are engaged with each other, so that the axes of the input shaft 1A and the output shaft 1B are completely aligned.
Accurate drilling is possible.

Next, when the drill at the tip of the output shaft 1B is replaced with a tap for tapping, the spindle 1 is rotated at a low speed. In this case, since the centrifugal force due to the rotation is small and the steel ball 7a does not move the inner cup 3 upward, the floating gaps 6C and 6E between the inner cup 3 and the outer cup 2 remain unchanged. When the spindle 1 descends in this state, first, the tap bites into the hole of the workpiece. At that moment, the tap is pulled into the hole, so that the floating gap 6E in the pulling direction contracts and slightly moves the output shaft 1B downward. If the floating gap 6 in the pulling direction
If there is no E, the force that raises the workpiece acts at the moment the tap bites into the hole of the workpiece, but since there is no escape place for that force, the hole is scraped by the tap,
As a result, the accuracy of the screw will drop.

Next, when the tapping is in the orbit, the calculated feed amount of the spindle 1 exceeds the tapping speed of the tap due to a mechanical error, and a force in the compression direction acts on the spindle 1. Upon receipt of this compressive force, the floating clearance 6C in the compressing direction is contracted to absorb the excessive feed amount of the spindle, and the tapping is reliably advanced without machining error. When the tapping process is completed, the spindle 1 is rotated in the opposite direction to remove the tap from the workpiece. Also in this case, the loose clearance effectively functions, so that the female screw is not damaged.

The present invention has been described above with reference to the embodiments.
Of course, the present invention is not limited to the above embodiment. For example, as the tapping drilling machine, a so-called NC control machine in which the rotation and the feed of the spindle 1 are controlled by the control device is exemplified, but a tapping drilling machine in which the spindle 1 is manually moved up and down by a feed handle is also applicable. Also,
The present invention can be easily implemented even by adding the forward / reverse rotation function to the drilling machine having no reverse rotation function of the spindle by electrical control.

Further, the shaft connecting means 4 for connecting the input shaft 1A and the output shaft 1B has, in addition to the spline 4a as illustrated, axial slide grooves on the outer circumference of the inner cup 3 and the inner circumference of the outer cup 2, respectively. Alternatively, a key-shaped metal rod may be inserted so as to extend over both slide grooves. Furthermore, and more preferably, as shown in FIGS. 5 and 6, a plurality of balls 4 are provided between the inner cup 3 and the outer cup 2.
A so-called radial type ball spline interposing b and 4b is preferably used. This radial type ball spline has balls 4b, 4b positioned in the vertical grooves 4c, 4d on the outer circumference of the inner cup 3 and the inner circumference of the outer cup 2 by spacers 4e. By using the radial type ball bearing in this way, the inner cup 3
Since the sliding resistance of the outer cup 2 in the axial direction is drastically reduced, it is suitable for processing fine screws.

Although the coil spring 5a is illustrated as the biasing means 5 in the embodiment, a leaf spring or a rubber shaft joint may be used in addition to the coil spring 5a, or the taper cylinder 2a of the outer cup 2 and the inner cup 3 may be used. Axis fixed cylinder 3
Permanent magnets may be fixed to the ends of a to utilize the repulsive force of the magnetic force.

In the embodiment, the centrifugal force converting means 7 is provided with the guide groove 7b in the cup body 2c of the outer cup 2 and the steel ball 7a is placed there. However, when it is difficult to machine the guide groove 7b. The guide groove 7b is formed in the bowl-shaped body 7c as shown in FIG. 7, and the bowl-shaped body 7c is fitted into the cup body 2c, or the guide groove 7b is formed in the cup body 2.
The outer surface of c may be penetrated. Further, the centrifugal force converting means 7 may use a weight and a link mechanism, and in the end, may have any structure as long as it has a function of converting the centrifugal force into an axial force. .

The centering means 8 is the outer cup 2
The V groove 8a may be provided in the inner cup 3, and the chevron rib 8b of the inner cup 3 may be provided in the outer cup 2. Furthermore, the shape and number of grooves and ribs are also free.

In the embodiment, the outer cup 2 is connected to the input shaft 1A and the inner cup 3 is connected to the output shaft 1B. Conversely, the inner cup 3 is connected to the input shaft 1A and the output shaft 1 is connected.
The outer cup 2 may be connected to B. Also, ultimately, the output shaft 1B is omitted and the inner cup 3 is omitted.
It is also possible to directly attach a collet chuck or a universal chuck to the. Needless to say, even such a structure is equivalent to the present invention.

[0024]

As described above, the tapping drilling machine of the present invention automatically switches between drilling and tapping using the difference in the number of rotations of the spindle. Need not be replaced. Therefore, since only the small and light cutting edge tool needs to be replaced, workability is good, and the risk of breakage even if the cutting edge tool is accidentally dropped is low. Further, since the unit in which the inner cup and the outer cup are integrated may be mounted as a head on a spindle such as an existing tapping drilling machine, there is an advantage that the introduction cost is minimal.

If a floating clearance in the pulling direction is also formed between the input shaft and the output shaft as in claim 2, the direction in which the workpiece is lifted at the moment when the tap bites into the hole in the workpiece. Even if the force of the above is applied, the force is absorbed by the floating gap in the pulling direction, so there is no fear that the hole will be cut by the tap, and as a result, an accurate internal thread can be processed, which is excellent in practical use. Be effective.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part showing a tapped state.

FIG. 2 is a vertical cross-sectional view of a main part showing a punched state.

FIG. 3 is an exploded perspective view of a main part with a part cut away.

FIG. 4 is a sectional view taken along line YY of FIG.

FIG. 5 is an exploded perspective view of an outer cup and an inner cup according to another embodiment.

FIG. 6 is a cross-sectional view of main parts of an outer cup and an inner cup showing another embodiment.

FIG. 7 is a perspective view of a bowl-shaped body.

[Explanation of symbols]

1… Spindle 1A ... Input shaft 1B ... Output shaft 4 ... Shaft connection means 5 ... Biasing means 5a ... Coil spring 6C ... Floating clearance in compression direction 6E: Floating clearance in the pulling direction 7 ... Centrifugal force conversion means 8 ... Centering means

Claims (2)

(57) [Claims] 1. A spindle which is divided into an input shaft and an output shaft, and a shaft connecting means for connecting the output shaft to the input shaft so as to be slidable in the axial direction and integrally in the rotational direction. And an urging means such as a coil spring that forms an axial clearance between the input and output shaft ends, and the centrifugal force generated by the rotation of the spindle is converted into an axial force. Is moved to the input shaft side, and centrifugal force conversion means for setting the floating clearance in the compression direction to “0” under the condition that the spindle is in the high-speed rotation range necessary for drilling, and the input shaft and the output shaft. A tapping drilling machine, comprising: centering means for aligning the shaft centers of the two shafts in a state where a floating clearance "0" is joined. 2. The tapping drilling machine according to claim 1, wherein an axial play gap provided between the shaft ends of the input shaft and the output shaft corresponds to a bidirectional force of compression and tension. .