JPS6116004Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drilling/tapping unit, and more particularly to an automatic drilling/tapping unit having a rapid feed mechanism and driven by an electric motor.

Conventionally, there has been an automatic drilling/tapping unit as a hole-drilling/tapping machine that is compactly constructed by integrally incorporating a rotary drive machine, a forward/backward movement mechanism, etc. Most conventional devices operate at the same feed rate throughout the entire process, from when the device moves forward to perform hole drilling and screw processing, to when it retreats and returns to its original position, i.e., at a feed speed that is compatible with the screw pitch, etc. Because it moves forward and backward, the drill tap is used for drilling and drilling holes.
During the idle feed process before thread machining and the idle return process after completing hole machining and screw machining, the machine moves back and forth at a feed speed that matches the screw pitch, etc.
Particularly in screw machining, the number of rotations is relatively low due to the nature of the tapping operation, so the time required for idle feeding and idle return takes up a large proportion of the total working time.

Therefore, the applicant has proposed various devices that move back and forth at high speed during dry feed and return, and has already filed an application.
This relates to an improvement of the tapping unit.The gist of the invention is that the spindle, which is rotationally driven by an electric motor, is driven forward at high speed by an air piston, and during the cutting process, the rotation of the rotary drive shaft and the ball screw are used to determine the rotation of the tapping unit. The object of the present invention is to provide a device that feeds a screw forward and backward at a cutting feed rate, and after cutting is finished, moves back at high speed using an air piston and returns to the original position to complete one cycle of machining. That is, the aim is to shorten the process time required for one cycle by increasing the idle feeding and idle return speeds.

The present invention will be explained in detail with reference to an embodiment in which the present invention is applied to the illustrated tapping unit. Reference numeral 1 designates the main body of the tapping unit, in which a cylindrical shaft 2 is housed in the front part so as to be movable back and forth, an electric motor 3 is fixed to the rear part, and the cylindrical part 2 is mounted at a predetermined position in the center. A valve block 4 for controlling forward and backward movement is integrally constructed. Reference numeral 5 denotes a spindle which is rotatably fitted and supported in the cylindrical shaft 2, the front end of which is formed to have a small diameter and serves as a tool shaft attachment part 6, and the rear end thereof is formed into a hollow shape and has an opening at the rear end surface. Inwardly protruding tooth-like protrusions 7 are carved at predetermined positions. The cylindrical shaft 2 has a diameter expanded at a predetermined position in the center to form a piston 8, which is slidably fitted into an inner cylinder 9 fitted to the body 1, and a portion extending rearward from the piston 8 has a smaller diameter. The center bar 10 is formed by forming the center bar 10.
Reference numeral 11 denotes a drive shaft, which has a toothed shaft portion 12 formed over a predetermined length at its front end, penetrates the center bar 10, and engages with the toothed protrusion 7 carved into the cylindrical shaft 2. At the same time, a belt pulley 13 is locked to the rear end portion, and the belt pulley 16 is locked to the output shaft 15 of the electric motor 3 via a belt 14 to drive rotation. A gear 17 is locked at a predetermined position on the drive shaft 11, and is engaged with a gear 19 that is locked on the intermediate shaft 18. A gear 20, which is also locked on the intermediate shaft 18, is locked on the gear shaft 21. The gear 22 is engaged with the gear 22. Reference numeral 23 denotes an adjustment member, which is screwed into an abutment plate 24 that is engaged with the center bar 10 that is integrally formed with the piston 8. Reference numeral 25 denotes a rotary plate rotatably supported by the adjusting member 23, and a spline portion 26 carved in the front end of the gear shaft 21.
Internal teeth 35 are provided to engage with the front end surface, and tooth-like protrusions 36 are provided on the front end surface. 27 is a ball screw shaft; 28 is a ball nut having a toothed protrusion 37 on its rear end surface that engages with the toothed protrusion 36;
29 is a spring that urges the ball nut 28 rearward, and 30 is a retaining ring. 31 and 32 are cylinder chambers formed by the piston 8 within the inner cylinder 9. 33 is a sealing member fitted into the piston 8. 34 is a ventilation passage formed by the body 1 and the inner cylinder 9.

In the above-described configuration, the electric motor 3 rotates in the forward direction in response to the operation start signal, and drives the drive shaft 11 to rotate via the output shaft 15, the belt pulley 16, the belt 14, and the belt pulley 13. The rotation of the drive shaft 11 rotates the spindle 5 via the toothed protrusion 7 engaged with the toothed shaft portion 12 at the front end, thereby causing the tool shaft mounting portion 6 to rotate. Furthermore, the gear 17 locked at a predetermined position on the drive shaft 11 is rotated, and the gear shaft 21 is rotated through the gear 19, the intermediate shaft 18, the gear 20, and the gear 22.
In order to rotate the rotary plate 25, the rotary plate 25 is rotated by internal teeth 35 that engage with a spline portion 26 provided at the front end of the gear shaft 21. At the same time as the electric motor 3 is started, various valves (not shown) incorporated in the valve block 4 work together to supply compressed air to the cylinder chamber 32, and as a result, the piston 8 slides against the inner surface of the inner cylinder 9. The cylindrical shaft 2 is integrally formed with the piston 8 in order to move forward while contacting the piston 8.
The center bar 10 also moves forward together with the piston 8. The plywood 24 is locked to the center bar 10 as the center bar 10 moves forward.
At the same time, the adjustment member 23 screwed onto the abutment plate 24 moves forward as a unit. Here, the gear shaft 21 is the body 1
It is supported by the rotating plate 25 and is configured to be immovable in the axial direction, and allows displacement in the axial direction while transmitting rotation to the rotary plate 25. That is,
Internal teeth 3 of rotary plate 25 that engage with spline portion 26
5 rotates the gear shaft 21 and the rotating plate 25 integrally, and also moves the rotating plate 25 forward as the abutment plate 24 moves forward. On the other hand, the drive shaft 11 rotates the spindle 5 by means of toothed protrusions 7 engaged with the toothed shaft portion 12, and allows the spindle 5 to move back and forth in the axial direction integrally with the piston 8. In this way, the spindle 5 is rotated and moved forward by the electric motor 3. The forward speed at this time is determined by the amount of compressed air sent into the cylinder chamber 32, and is set to a relatively high speed compared to the cutting feed speed in the next step. While the spindle 5, drive shaft 11, gear shaft 21, and rotary plate 25 rotate in this manner, the piston 8, spindle 5, center bar 10, abutment plate 24, and rotary plate 25 move forward integrally, and move forward a predetermined distance. The rotating plate 25 abuts against the rear end surface of the ball nut 28. The collision between the rotary plate 25 and the ball nut 28 prevents the piston 8, spindle 5, center bar 10, abutment plate 24, and rotary plate 25 from moving forward, which had been moving forward at high speed. Compressed air is still being supplied to the piston 8, and the piston 8 is always urged in the forward direction. Therefore, center bar 10,
The rotary plate 25 is connected to the ball nut 2 via the plywood plate 24.
It will be pushed to 8. Since the rotating plate 25 is constantly rotating, when it collides with the ball nut 28,
The toothed projections 36 and 37 protruding from the rotary plate 25 and the ball nut 28 engage with each other in a meshing state, and the toothed projections 36 and 37 prevent the rotation of the rotary plate 25, that is, the gear shaft 21, from the ball nut 2.
8, the ball nut 28 moves forward while being screwed into the ball screw shaft 27 against the force of the spring 29. Here, the forward speed of the piston 8 after the rotating plate 25 collides with the ball nut 28 is determined by the thread pitch of the ball screw shaft 27 and the ball nut 2.
The rotation speed of the ball nut 28 is equal to that of the rotating plate 25, and is determined by the ratio of the number of teeth of the gears 17, 19, 20, and 22 to the rotation speed of the drive shaft. The advancing speed of the ball nut 28 per unit rotation of the shaft 11 can be set in advance, and a cutting feed rate that is slower than the idle feed is set according to the thread pitch to be cut. The spindle 5, which is rotationally driven by the drive shaft 11, is propelled by the piston 8 and is controlled by the ball screw shaft 27 and the ball nut 28, while the spindle 5 is rotated by the tap (not shown) that is locked to the tool shaft attachment part 6. ) to perform the cutting process.
When moving forward a predetermined distance, a collision member (not shown) attached to the collision plate 24 collides with a switch (not shown) attached to the body 1, and the electric motor 3 is rotated by a signal emitted from the switch. The drive shaft 11,
The spindle 5 and gear shaft 21 are rotated in the opposite direction. On the other hand, compressed air is still being fed into the cylinder chamber 32 and pressing the piston 8 forward, but the gear shaft 21 causes the ball nut 28 to reversely rotate via the rotary plate 25. is unscrewed from the ball screw shaft 27 and retreats in the opposite direction, and the rotating plate 25 and the abutment plate 2
4. The piston 8 is moved rearward against the pressing force of the compressed air being fed into the cylinder chamber 32 via the center bar 10. It is clear that the backward speed at this time is the cutting feed speed during the forward movement, since only the rotational direction of the electric motor 3 is reversed, and the rotational transmission path is not changed at all. Next, when the tap (not shown) locked on the tool shaft attachment part 6 is completely detached from the workpiece (not shown), the abutment member (not shown) attached to the abutment plate 24 By configuring it so that it collides with a switch (not shown) attached to the body 1, various valves (not shown) incorporated in the valve block 4 are interlocked with signals emitted from the switch, At the same time, the supply of compressed air to the cylinder chamber 32 is cut off, and at the same time, the air passage 3
By feeding compressed air into the cylinder chamber 31 through the piston 4, the piston 8 is pushed backward in the opposite direction. The piston 8 that has been pushed backward moves back together with the spindle 5, center bar 10, abutment plate 24, and rotating plate 25, and at the backward end position, the abutment member (not shown) attached to the abutment plate 24 switches the switch ( (not shown), the signal emitted from the switch causes various valves (not shown) built in the valve block 4 to operate in conjunction with each other, thereby cutting off the supply of compressed air to the air passage 34, thereby blocking the piston 8. At the same time, the power supply to the electric motor 3 is cut off to stop the electric motor 3, thereby completing one cycle of machining.

The foregoing is a description of a preferred embodiment of the tapping unit, but the tapping unit can also function very suitably as a drilling unit by drilling the tap that locks onto the tool shaft mounting portion 6. It's something you get.

In this way, in the cutting process, the tool is moved forward and backward at a slow cutting feed rate that matches the cutting conditions.
In the idle process where cutting is not performed, the air piston/cylinder is used to move back and forth at high speed, thereby shortening the machining time and reducing the machining cost. At the same time, since the cutting feed rate is forced feed by the screw device, it is certain that the tap will bite into the workpiece material at the beginning of thread cutting, and that the tap will not come off at the end of thread cutting. This makes it possible to perform precise screw machining, and the effect is particularly significant when machining small diameter screws on thin workpieces. In addition, in hole machining, the cutting feed rate is more stable compared to conventional hydraulic speed governors, etc., and in through-hole machining, it is also possible to prevent excessive cutting of the drill due to sudden load fluctuations when the drill penetrates. This can have significant effects such as preventing Further, according to the present invention, the device can be constructed compactly with a small number of components.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention, FIG. 2 is an enlarged external view of the main part in FIG. 1, and FIG. 3 is a view taken along the line A--A in FIG. 2. 1: Body, 3: Electric motor, 8: Piston, 9:
Inner cylinder, 10: Center bar, 11: Drive shaft, 17: Gear, 19: Gear, 20: Gear, 2
2: Gear, 24: Plywood plate, 25: Rotating plate, 27:
Ball screw shaft, 28: ball nut, 36: tooth-like process, 37: tooth-like process.

Claims (1)

[Scope of utility model registration request] Drilling equipment that is rotationally driven by an electric motor and driven forward and backward by a hydraulic piston-cylinder mechanism.
In the tapping unit, there is an abutment plate that is engaged with a center bar that is integrated with a hydraulic piston, a gear that is engaged with a drive shaft that is rotationally driven by an electric motor, and a drilling/tapping unit body that is It comprises a locked screw/nut device, and a rotary plate that rotates together with a gear shaft rotationally driven via a gear locked to a drive shaft and is rotatably supported by the abutment plate, The plate rotates together with the gear shaft and is supported so as to be movable in the axial direction, and has a frictional engagement surface on its front end surface that can freely engage and disengage from the frictional engagement surface provided on the rear end surface of the nut. A drilling/tapping unit characterized in that the gear shaft and the screw shaft are arranged substantially on the same straight line.