JPS6374518A - Tapping machine - Google Patents

Abstract

PURPOSE:To reduce manufacturing cost and prevent a tap from breaking by mounting a main spindle guide member to be thread-engaged with a main spindle on a mounting section attached detachably to a machine frame, detecting the movement of the guide member relative to the mounting section, and separating the tap from a workpiece. CONSTITUTION:A male thread portion 19 having a same pitch with that of a tap 20 is formed on the peripheral part of a main spindle 16 of a tapping unit 2A while a female thread portion 22 is formed on the inner circumferential part of a main spindle guide member 21. The male thread portion 19 is screwed into the female thread portion 22 by the positive rotation of the main spindle 16, the main spindle 16 lowers by a distance corresponding to the pitch of the tap 20, and the tap 20 is inserted into a guide hole of a workpiece on a table 5 to perform thread cutting. If the tap 20 comes into contact with other part of the workpiece than the guide hole, lowering of the main spindle 16 is restricted, an upward shifting force acts on the guide member 21, and the main spindle 16 and the tap 20 are raised by means of a circuit which rotates a motor 12 in a reverse direction. With the above constitution, manufacturing cost can be reduced and accidental breakage of the tap can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a tapping machine that forms a screw hole in a workpiece while applying a feed motion to a tap.

(Prior Art) In a conventional tapping machine that forms a screw hole in a workpiece while applying a feed motion to a tap,
A rack is formed on the main shaft, and the rotation of the main shaft is reduced and transmitted by a speed reducer to give the main shaft a feed motion that matches the lead of the tap. In addition, some of the gears in the reducer are configured to be replaceable in order to match the lead of the tap with the feed of the main shaft.

(Problems to be solved by the invention) However, with the conventional structure, the deceleration of the reducer is large, so multi-stage reduction is required, the structure is complicated, and it must be mounted with high precision. However, the production cost is high, and the reduction gear gears have to be changed when changing the feed rate of the main shaft, making it difficult to handle.

Therefore, the first object of the present invention is to provide a tapping machine that has a simple configuration, low production cost, and is easy to handle. When this happens, this is detected and the tap can be moved in the direction away from the workpiece.

[(1'4) of the invention (Means for solving the problem) A first means of the present invention is that a tap is attached to one end, and a male thread part with the same pitch as the tap is formed on the outer periphery. A spindle guide member having an inner circumferential portion formed with a female thread portion for screwing the male thread portion of the spindle is provided, and the spindle guide member is removably attached to the machine frame together with the spindle. The present invention is characterized in that the machine frame is provided with a drive shaft that is reciprocally rotated by a motor and transmits rotational force to the main shaft.

Further, in the second means of the present invention, in the first means, the main shaft guide member is mounted on the mounting portion of the machine frame so as to be movable together with the main shaft, and the main shaft guide member is mounted relative to the mounting portion. A detection device is provided to detect this movement, and a control circuit is provided to rotate the motor in reverse when the detection device is activated to move the tap attached to the main shaft in a direction away from the workpiece. It has some characteristics.

(Function) According to the first means, since a multi-stage, high-precision reduction gear is not required, the structure is simple and can be produced at a low cost of 11 tons, and it is easier to handle than the conventional one in which gears are replaced. Become.

According to the second means, when an unreasonable force is applied to the main shaft during thread cutting, the main shaft is moved in a direction in which the tap is separated from the workpiece, and the tap is damaged or the workpiece is damaged. Scratches are reliably prevented.

(Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 1 is a machine frame made of sheet metal and formed in a substantially U-shape. A nut 3 is fixed by welding or the like in the lower machine frame 2 of this machine frame, and a table 5 is attached to the upper end of a threaded rod 4 screwed into this nut 3. is fixed by welding, etc. Upper machine frame 6 of machine frame L
A cylindrical body 7 facing directly above the table 5 is fixed to the table 5 by welding, and a drive shaft 9 is rotatably supported on the inner periphery of the cylindrical body 7 via a ball bearing 8.8.

A pulley 1o is fixed to one -1 end of the drive shaft 9, and a square connecting hole 11 is provided at the lower end. 1
2 is a motor fixed to the upper end of the support part 13 of the machine frame 1;
A pulley 14 is fixed to the rotating shaft 12a, and a belt 15 is stretched between the pulley 14 and the pulley 1o. Reference numeral 16 denotes a main shaft with a chuck 17 fixed at its lower end, and a connecting portion 18 with a rectangular cross section that can be movably fitted into the connecting hole 11 is formed at the upper end of this main shaft. A male threaded portion 19 is formed in the part, and the pitch thereof is set to the same dimension as the tap 20 attached to the chuck 17. Reference numeral 21 indicates a female thread into which the threaded portion 19 is screwed. The main shaft guide member is formed with a portion 22, the outer circumferential portion of which is set to a diameter that can be fitted to the inner circumference of the cylindrical body 7, and has two four portions 23 that face each other with the center line in between.
．． 23 is formed. A thread cutting unit 24 is constructed by screwing the male threaded portion 19 of the main shaft 16 into the female threaded portion 22 of the main shaft guide portion 21, and this thread cutting unit 24 is provided with several sets of stages depending on the type of tap 2o. There is. That is, since it is necessary to set the pitch of the tap 2o and the pitch of the male thread part 19 and the female thread part 22 to the same dimension, the thread cutting unit 2 is adjusted to the pitch of the tap 2o.
4 are prepared, and the tap 20 is inserted into the main 1II 116 of the thread cutting unit 24 via the chuck 17, the pitch of which is equal to the pitch of the male threaded portion 19 and the female threaded portion 20. Main shaft guide portion 21 of this thread cutting unit 24
is removably and movably fitted into the mounting part 25 at the lower end of the cylindrical body 7, and the connecting part 18 of the main shaft 16 is fitted into the connecting hole 11 of the drive shaft 9 so that IF1 can move. 26 is the main shaft guide member 21
This is a holding plate that prevents the upper machine frame from falling downward, and is fixed to the lower surface of the upper machine frame 6 via screws 27, 27. Horizontal holes 2B, 2B facing the recesses 23.23 are formed in the mounting portion of the cylinder 7, and one of the horizontal holes 28 communicates with a guide cylinder 29 that opens toward the outside of the upper machine frame 6. A threaded portion 29a is formed on the inner periphery of the guide tube 29.

A ball 30 and a coil spring 31 are arranged on the inner periphery of the guide cylinder 29, and an adjusting screw 32 is screwed into the threaded portion 29a. A ball 33 is disposed in the other horizontal hole 28, and the pin of the microswitch 34 is in contact with this ball 33. On the other hand, 35 is a guide body fixed to the outer surface of the upper machine frame 6. The actuator M36 is supported by this so that it can slide in the vertical direction, and a U-shaped connecting portion 37a provided at the tip of a plate 37 fixed to the lower end of the actuating shaft 36 connects to the lower end of the main shaft 16. An annular groove 3 provided nearby
8 is fitted. A ring 3 is located in the middle of the operating shaft 36.
9 is provided so that its movement can be adjusted using screws, etc.

An operator of a microswitch 40 is opposed to the two ends of the operating shaft 36, and an operator of a microswitch 41 is opposed to the ring 39. The microswitch 42 is disposed within the upper machine frame 6, and its operator is opposed to the presser plate 26 through the hole 6a, so that the operator is held down by the presser plate 26. There is. Further, 43 is a coil spring that biases the main shaft guide portion 21 mounted on the mounting portion 25 downward.

In the electrical circuit diagram shown in FIG. 3, 44 is a power switch, 45 is a start switch, 46 and 47 are relays, 4
6 a T'J to 46c are contacts of the relay 46, 47a to 47c are contacts of the relay 47, 48 and 49 are capacitors, and 50 is a fuse.

Next, the operation of the above configuration will be explained. When the power switch is turned on and the start switch 45 is turned on, the relay 46 contacts the relay contact 47b.

The relay contact 46a is energized through the contacts (a-C) of the microswitch 41, the contacts (a-C) of the microswitch 34, and the microswitch 42 in this order.
The motor 12 is energized via the energizer, and the motor 12 is rotated in the forward direction. The rotation of the motor 12 is transmitted to the drive shaft 9 via the belt 15.
, the main shaft 16 is rotated in the forward direction, and the main shaft 16
When the tap 20 is rotated, the male threaded portion 19 is screwed into the female threaded portion 22 and descends in accordance with the rotation, and its lowering limit becomes a value that matches the pitch of the tap 20. The tap 20 is screwed into a prepared hole of a workpiece (not shown) placed on the table 5'' to perform thread cutting. When the thread cutting is completed, the ring 39 hits the operator of the microswitch 41 and switches the microswitch 41 to open the contacts (C-a) and close the contacts (b-c), so that the relay 46 is activated. Relay contact 4 is disconnected
6a is opened and relay contact 46b is closed. Then, the relay 47 connects to the relay contact 46b and the micro switch 4.
1 and between the contacts (C and A) of the microswitch 34, as well as through the microswitch 42, and the relay contact 47a.

47c, the motor 12 is connected to the relay contact 4.
The relay 47 is energized through 7a and rotates in reverse, and the relay 47 connects the relay contact 46b, the relay contact 47C, and the micro switch 40.
and 42 continue to be energized. When the motor 12 rotates in the reverse direction, the main shaft 16 is raised while rotating in the reverse direction.
The tap 20 is removed from the threaded hole after thread cutting.

When the main shaft 16 reaches the upper yt position, the operator of the microswitch 40 is pressed and opened at the upper end of the operating shaft 36, the relay 47 is cut off, and the relay contact 47a is opened, so the motor 12 is stopped. . By repeating the above steps, the prepared hole of the workpiece is threaded (tapped) and a screw hole is formed.

When the start switch 45 is operated and the main shaft 16 and tap 20 descend while rotating in the forward direction, if the workpiece is set incorrectly and the tap 20 hits a part of the workpiece that is not the pilot hole, the main shaft 16 will be lowered. is regulated, so a moving force in the L direction is applied to the main shaft guide portion 21. By tightening the screw 32 and compressing the fill spring 31, the main shaft guide member 21 engages the ball 30 in the recess 23 with the biasing force generated in the yielding coil spring 31, thereby allowing the ball 30 to engage with the recess 23 in normal tap standing. When the main shaft guide member 2
1 is prevented from increasing. However, the descent of the main shaft 16 is regulated in a double series, and the main shaft guide member 21
When a moving force in the two directions is applied, the ball 30 moves in the direction of arrow A against the biasing force of the coil spring 31, so that the main shaft guide member 21 moves upward. Along with this, the ball 33 is moved in the direction of arrow B, and the ball 33 is moved in the direction of arrow B.
3 suppresses the operator of the microswitch 34,
The contacts (a-C) of the microswitch 34 are opened,
The contacts (b-c) are closed. Then, the relay 46 is energized and the relay contact 46a is closed.

46c are respectively opened, and the relay 47 is connected to the relay contact 4 instead.
6b, the relay contact 47a as in the normal case since electricity is supplied between the contacts (b-C) of the microswitch 34 and through the microswitch 42;

47c are respectively closed, and the motor 12 is connected to the relay contact 47a.
The main shaft 16 is rotated in the reverse direction by being energized through the main shaft 16, and the main shaft 16 is raised by 1 while rotating in the reverse direction. Since the "-H" and stop of the main shaft 16 are exactly the same as in the normal case, a detailed explanation will be omitted.

On the other hand, when replacing the thread cutting unit 24, first open the power switch 44, loosen the screws 27 and remove the presser plate 26, loosen the adjustment screws 32 and pull out the thread cutting unit 24 downward, and then perform another thread cutting operation. unit 2
4 is to be attached. By the way, since the microswitch 42 is opened when the holding plate 26 is removed, even if you forget to open the power switch 44 and replace the thread cutting unit 24, there is no risk that the motor 12 will suddenly rotate during replacement. can be prevented from occurring.

In the above configuration, it is only necessary to form the threaded portion 19 on the outer periphery of the main shaft 16 of the thread cutting unit 24 and the female threaded portion 22 on the inner periphery of the main shaft guide member 21. Since a high-precision filter is not required, the configuration is Il'! 'Can be manufactured at low cost with 1 tlt.

Furthermore, in the above configuration, the thread cutting unit 24 is replaced when the pitch of the tap 20 is different.
It is easier to handle than the conventional structure in which the gears inside the reducer are replaced.

Historically, in the above 1+'is construction, when an unreasonable force is applied to the main shaft 16, for example, when the tap 20 hits a position outside the lower hole of the workpiece, the upper seat of the main shaft guide member 21 moves. Since the motor 12 is immediately reversed and the main shaft 16 is moved upward when the tap 20 is detected, breakage of the tap 20 or damage to the workpiece can be reliably prevented.

FIG. 4 shows a second embodiment of the present invention, and only the parts different from the first embodiment will be explained. First, one side hole 2
8 and one of the four sections 23 have been removed. Also, ball 3
0, a stepped shaft 51 having a spherical portion 51a at its tip is movably inserted into the guide tube 29, and a coil spring 31 is disposed around the outer periphery of the small diameter portion 51b of this stepped shaft 51. The nut 52 that adjusts the amount of compression of the coil spring 31 is provided with a hole 52a in the center, and the small diameter portion 51b fits into the hole 52.
It penetrates through 2a and projects to the outside. On the other hand, the operator of the microswitch 34 is opposed to the protruding end of the small diameter portion 51b.

In this configuration, Lord? When an unreasonable force is applied to th16 and the main shaft guide member 21 rises, the stepped shaft 50 moves in the direction of arrow A and switches the microswitch 34. The structure and operation are similar to the first embodiment.

FIG. 5 shows a third embodiment of the present invention, and only the differences from the first embodiment will be explained. That is, the main shaft guide member 2
The main shaft guide member 53 provided in place of 1 includes an outer cylinder 55 having a concave portion 54, 54 similar to the fourth part 23, and this outer cylinder 5.
5 and an inner cylinder 57 having a female threaded part 56 on the inner surface into which the male threaded part 19 of the main shaft 16 is screwed. At 59, the inner cylinder 57 is prevented from being exposed from the outer cylinder 55. Although the outer cylinder 55 is movable relative to the valley portion 25 of the cylinder body 7, it is normally prevented from being removed downward from the cylinder body 7. In this embodiment, for example, the outer cylinder 55
The inner cylinder 5 is made of an inexpensive steel material and has a female threaded portion 56.
7 is made of gunmetal so that there is no risk of seizure with the male threaded portion 19.

Then, the main shaft 16 and the inner cylinder 57 are removed from the outer cylinder 55 and replaced. Reference numeral 60 designates a holding plate that takes the place of the holding plate 26, and its both ends are fixed to the lower surface of the upper machine frame 6 with screws 61 and 61 to prevent the inner r257 from being removed downward from the outer cylinder 55. . The microswitch 42 is turned on when the presser plate 60 is attached. The third embodiment described above also provides the same effects as the first embodiment.

[Effects of the Invention] As is clear from the embodiments described above, the present invention is configured such that the male threaded portion of the main shaft is screwed into the female threaded portion of the main shaft guide member, so the structure is simple and the manufacturing cost is low. It is inexpensive and easy to handle, and when unreasonable force is applied to the spindle during thread cutting, it can be detected and the tap moves away from the corrugated workpiece, which prevents damage to the tap. It has the excellent effect of preventing

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is an overall vertical sectional side view, FIG. 2 is a side view of the upper part, and FIG. 3 is an electrical configuration diagram. FIG. 4 is a vertical cross-sectional view of the main part showing a second embodiment of the present invention, and FIG. 5 is a vertical cross-sectional view of the main part showing a third embodiment of the invention. In the drawing, 1 is the machine frame, 7 is the cylinder body, 9 is the drive shaft, and 12 is the motor.
16 is the main shaft, 17 is the chuck, 19 is the male thread part, 2
0 is a tap, 21 is a main shaft guide member, 22 is a female thread part,
24 is a thread cutting unit, 25 is a mounting part, 26 is a holding plate, 34.40 to 42 are micro switches, 46.47
53 is a relay, 53 is a main shaft guide member, and 55 is a female screw portion. Applicant Shigeru Ikemoto Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. A main shaft having a tap attached to one end and a male threaded portion having the same pitch as the tap on the outer periphery, and a female threaded portion for screwing the male threaded portion of this main shaft. a main shaft guide member formed on an inner circumferential portion; a mounting portion provided on the machine frame to which the main shaft guide member can be removably mounted together with the main shaft; A tapping machine comprising a drive shaft that transmits rotational force to the main shaft. 2. A main shaft with a tap attached to one end and a male thread with the same pitch as the tap on the outer periphery, and a female thread on the inner periphery for screwing the male thread of the main shaft. a main shaft guide member provided in the machine frame, a mounting part provided on the machine frame to which the main shaft guide member can be mounted movably together with the main shaft, and a mounting part provided on the machine frame so as to be reciprocally rotated by a motor to apply rotational force to the main shaft. A drive shaft for transmitting the transmission; a detection device for detecting when the main shaft guide member moves relative to the mounting portion; and a detection device for detecting when the main shaft guide member moves relative to the mounting portion, and a tap mounted on the main shaft by rotating the motor in the reverse direction when the detection device is activated. and a control circuit for moving the workpiece in a direction away from the workpiece.