JPH05253716A - Boring unit - Google Patents

Abstract

PURPOSE:To detect change in currents flowing in motors to provide control information, and to flexibly change the rotation and the feeding by making the rotational shaft of a spindle for rotating a drill and the shaft of the force for moving the drill forward and backward, of the same axis, by inhibiting the rotational shaft of the drill from being tilted during cutting, and by preparing different motors for rotating the drill and for moving the drill forward and backward. CONSTITUTION:A male screw 5 for moving a spindle 1 forward is formed into a hollow shape, and a shaft 4 is inserted into the hollow part, while a female screw 6 for moving the male screw 5 forward is fixed to the inside of a rotor 7 of a motor 15 for moving a drill forward, so that the male screw 5 can go through the doughnut like hollow part of the rotor 7. A motor 11 for rotating the drill and the motor 15 for moving the drill forward are prepared separately, and each current flowing in the motors is detected, to provide information for controlling the rotation and the feeding of the spindle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a drilling unit for efficiently drilling using a drill or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 2 and 3, a drilling unit has been constructed so that a drill can rotate and simultaneously move forward and backward. In the case of the conventional example of FIG.
The motor 29 and the shaft 24 are connected so that the rotational force of 9 is transmitted to the drill 35, and the rotational force is transmitted to the spindle 21 on which the shaft 24 is splined. Further, the spindle 21 is provided with ball bearing rings 32, 3 so that the drill 35 can be moved forward and backward.
It is fixed to the ram 22 via 2, 32, 32. The ram 22 performs the same operation as the piston shaft of the air cylinder, and when air is introduced into the advance side air inlet 28, air is introduced into the advance side cylinder air chamber 26. When supplied, the ram 22 moves forward, and when air is introduced into the return side air inlet 27, air is supplied to the return side cylinder air chamber 25 and the ram 22 retracts.

Further, when the drill 35 comes into contact with the work at a high speed, the drill 35 may be broken. To prevent this, the regulator 30 for adjusting the feed speed is provided in the ram 2.
It is connected to 2. Usually, the piston 36 of the regulator 30 is placed 2 to 3 mm before the drill 35 comes into contact with the work.
Is adjusted so as to contact the stopper 31.

In the case of the conventional example of FIG. 3, similarly to the conventional example of FIG. 2, the shaft 57, the spindle 58, the gear 52, the gear 53, and the gear 54 are combined so that the rotational force of the motor 51 is transmitted to the drill 59. There is. The rotation speed of the drill 59 is
It can be increased or decreased by changing the gear ratio of the gear 53 and the gear 54. Further, the ram 81 is connected to the female screw 66 so that the drill 59 can be moved forward and backward, and the drilling unit uses the motor 51 as a drive source and the electromagnetic clutches 68, 69, and 7.
By connecting only one of the five, it is possible to select any one of fast feed, cutting feed, and fast return of the ram 81.

In FIG. 3, power is transmitted between a gear 63 and a gear 64 at both ends of a solid line arrow in the figure by a gear not shown, and the gear 5 at both ends of a dotted line in the figure.
Power is also transmitted between the gear 5 and the gear 70. The electromagnetic clutch 68 connects and disconnects the pulley 61 and the gear 63. The electromagnetic clutch 69 connects and disconnects the gear 80 and the gear 63. The electromagnetic clutch 75 includes the gear 74 and the gear 7.
Connect 6 or separate.

The transmission route of the feed drive force of the ram 81 is as follows. In the case of fast feed, only the clutch 68 is connected, and the belt 60, the pulley 61, the clutch 68, the gear 63, the gear 64, and the male screw 67 are transmitted in this order from the motor 51. In the case of cutting feed, only the clutch 69 is connected, and the motor 52 drives the gear 52, the gear 53, the gear 54, the gear 55, the gear 70, the gear 71, the gear 72, the gear 73, the gear 80, the clutch 69, and the gear 63. , Gear 6
4, the male screw 67 is transmitted in this order. Further, in the case of fast return, only the clutch 75 is connected and transmitted from the motor 51 in the order of the belt 60, the pulley 61, the gear 62, the gear 74, the clutch 75, the gear 76, the gear 64, and the male screw 67.

The rotation of the male screw 67 is transmitted to the rotary encoder 78 via the gear 65 and the gear 77 so that the position of the ram 81 can be detected. An electromagnetic brake 79 is attached so that the ram 31 does not move when stopped. Further, the respective electromagnetic clutches, brakes, and motors are controlled by a microcomputer so as to operate according to a program set arbitrarily.
The conventional example of FIG. 3 is more complicated than the mechanism of the conventional example of FIG. 2, but since the ram feed mechanism is a motor feed, stable feed can be obtained and no air equipment is required.

[0008]

However, these conventional drilling units have the following problems. In FIG. 2, the regulator 30 for cutting feed has the spindle 21.
It is off the center of the axis of rotation. On the other hand, there is a gap of about 20 μm between the slide bearing 23 and the ram 22. Therefore, the piston 3 of the regulator 30
When 6 hits the stopper 31, the rotary shaft of the spindle 21 tilts with respect to the axis of the slide bearing 23 in the direction of arrow 33 in the figure. Furthermore, since the driving source for feeding the ram 22 is obtained from air, it is impossible to detect the thrust force during drilling and a stable feeding speed cannot be obtained. Further, when changing the cutting feed rate, it is necessary to adjust the scale of the regulator 30.

In the structure shown in FIG. 3, since the feed drive source is obtained from the motor 21 for rotating the spindle, the structure becomes complicated and the shape becomes large. Also in this case, it is impossible to detect the thrust force during drilling and a stable feed rate cannot be obtained. When changing the cutting feed speed, it is necessary to change the ratio of the gears 41 and 42.

An object of the present invention is to solve all of these problems, and while being smaller than conventional products, the rotation axis of the spindle does not tilt with respect to the traveling direction of the spindle, and the thrust force during drilling is reduced. An object of the present invention is to provide a punching unit that can detect and flexibly change its rotation and feed.

[0011]

To achieve the above object, a drilling unit of the present invention comprises a spindle 1 for supporting a drilling tool, a shaft 4 for transmitting a rotational driving force to the spindle 1, and a spindle 1 in a drilling direction. In a unit having a male screw 5 for advancing the male screw 5 and a female screw 6 engaged with the male screw 5, the male screw 5 for advancing the spindle 1 is made hollow, and a shaft 4 is passed through the hollow portion to make the male screw 5
The internal thread 6 for advancing the motor 1 is fixed inside the rotor 7 of the motor 15 for advancing the spindle 1.
The male screw 5 is configured to pass through the doughnut-shaped hollow portion of the rotor 7 of FIG.

Further, means for separately providing a drill rotating motor 11 for driving the shaft 4 and a spindle advancing motor 15, detecting currents flowing through the respective motors, and obtaining information for controlling rotation and feed of the spindle. The structure has

[0013]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention and is an end view taken along a plane including the central axis thereof. In FIG.
Reference numeral 1 is a spindle that supports a drill 13 and rotates. Reference numeral 2 denotes a ram that moves forward and backward integrally with the spindle 1 while rotatably supporting the spindle 1 by ball bearings 12 and 12. Reference numeral 3 is a slide bearing that engages via a key 14 so as not to rotate the ram 2 and supports the ram 2 movably only in the axial direction. Reference numeral 4 denotes a shaft which is spline processed, engages with the spindle 1, and transmits the rotational force of the drill rotation motor 11 to a tool such as the drill 13. Reference numeral 5 is a male screw integrally formed with the ram 2. Reference numeral 6 is a female screw that engages with the male screw 5 and advances the male screw 5. Reference numeral 7 denotes a rotor of a drill advancing / retreating motor 15 which is fixed to the female screw 6 and rotates the female screw 6. Reference numeral 8 denotes a stator that faces the rotor 7 of the motor 15 for drill advance / retreat. Reference numeral 9 is a drill position detecting sensor. Reference numeral 10 is a sensor for detecting the number of rotations of the drill.

With this structure, the rotation axis of the spindle 1 and the action axis of the force for moving the spindle 1 forward and backward are concentric with each other, so that the rotation axis of the spindle 1 is in the traveling direction of the spindle 1. The hole position accuracy is improved without tilting. When this embodiment is used, the rotational force of the drill rotating motor 11 is transmitted to the spindle 1 via the spline processing portion of the shaft 4 to rotate a tool such as the drill 13 and the drill advancing / retreating motor 15 is rotated. Due to the rotational force, the female screw 6 fixed to the rotor 7 is rotated, and the ram 2 integrated with the male screw 5 is moved forward in some cases,
If there is another time, move it back.

The drill position detecting sensor 9 is used for the ram 2.
The amount of movement of forward and backward movements of the drill 13 is detected to obtain position information of the drill 13, and the rotation number of the drill 13 is detected by the sensor 10 for detecting the number of rotations of the drill 13. These pieces of information are sent to a control unit (not shown). The information is used to control by feeding back the rotation of the drill rotation motor 11 or the rotation of the drill advancement / retraction motor 15. Therefore, since the rotation and the feed can be flexibly changed, the application range of the present embodiment is widened, and for example, thread cutting can be performed.

When the drill 13 is worn, a large amount of thrust is required for drilling, but in this embodiment, the current flowing through the stator 8 is detected and sent to a control unit (not shown) to perform drilling. It is possible to obtain the information on the thrust force and the wear state of the drill 13 can be known. Also, drill 1
When the workpiece 3 is penetrated, the torque applied to the drill and the thrust change. Therefore, changes in the currents flowing through the drill rotating motor 11 and the drill advancing / retreating motor 15 are detected, and by the control of the control unit, the feed speed is reduced to reduce the back burr generated on the work, thereby reducing the life of the drill. Has been extended.

[0017]

As described above, according to the present invention, the rotary shaft of the spindle for rotating the drill and the forward movement of the spindle,
By placing the axis of action of the retracting force on the same axis, there is an effect that the drill rotation axis does not tilt during cutting. Therefore, the hole position accuracy is improved by using this embodiment.

Further, by separately providing a motor for spindle rotation and a motor for spindle forward / backward, it is possible to detect a change in the current flowing through each motor. Therefore, by using these as control information, rotation and feed can be made flexible. The effect is that it can be changed. For example, according to the present embodiment, since the thrust force during drilling can be detected by detecting the current flowing through the stator of the forward / backward motor, it is possible to know the wear state of the drill. It also detects the current flowing through the motor for rotating the drill and the motor for moving the drill forward and backward, lowers the feed rate according to the changes in the torque and thrust applied to the drill when the drill penetrates the work, and reduces the back burr generated on the work. The life of the drill can be extended.

Further, according to the construction of this embodiment, air is not used as a drive source for the ram feed, and it is not necessary to transmit the rotational force by a complicated mechanism using a drill rotation motor, a gear, a clutch and the like. The structure is simple, there is no need for auxiliary equipment such as air, and it is small and has good operability.

[Brief description of drawings]

FIG. 1 is an end view showing a cutaway view of an embodiment of the present invention.

FIG. 2 is an end view showing an example of a conventional punching unit by cutting it.

FIG. 3 is an end view showing another example of a conventional punching unit in a cut state.

[Explanation of symbols]

 1,2,58 Spindle 2,22,81 Ram 3,23 Slide bearing 4,24,57 Shaft 5,67 Male screw 6,66 Female screw 7 Rotor 8 Stator 9 Drill position detection sensor 10 Drill rotation speed detection sensor 11 Drill Rotation motor 11 13, 35, 59 Drill 15 Drill forward / backward motor 25 Return side cylinder air chamber 26 Advance side cylinder air chamber 29, 51 Motor 30 Regulator 31 Stopper 68, 69, 75 Electromagnetic clutch 78 Rotary encoder 79 Electromagnetic brake

Claims (2)

[Claims] 1. A spindle for supporting a drilling tool,
In a unit having a shaft for transmitting a rotational driving force to the spindle, a male screw for advancing the spindle in a drilling direction, and a female screw for engaging the male screw, the male screw for advancing the spindle is hollow, and the shaft has the hollow portion. The internal thread for advancing the external thread is fixed inside the rotor of the motor for advancing the spindle, and the external thread passes through the donut-shaped hollow portion of the rotor of the motor. Drilling unit. 2. A means for obtaining information for controlling rotation and feed of the spindle by separately providing a motor for rotating a drill for driving the shaft and a motor for moving the spindle, detecting currents flowing through the motors. The drilling unit according to claim 1, which has.