JPS6312908Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a machine tool that is reciprocated by a driving member, such as a main shaft cylinder in a tapping machine, a drilling machine, or the like.

Generally, in this type of machine tool, the main spindle cylinder is moved forward from its original position based on a preset reciprocating stroke, and then moved back, but in reality, at the end of the forward stroke, inertia Because the main shaft cylinder is stopped in an overrun state and then moved forward, the reality is that the main shaft cylinder is not reciprocated accurately within a preset forward stroke. When the main shaft cylinder is overrun by inertia force in this way, problems such as the main shaft cylinder colliding with other members and being damaged occur.
For example, in the control of the vertical reciprocating motion of a spindle cylinder with a tap attached to it in a tap board, defects such as deep cuts of screw holes and damage to the tap have occurred.

The purpose of this invention is to eliminate the above-mentioned defects and provide a machine tool that can accurately reciprocate within a preset forward stroke range without overrunning the main shaft cylinder of a tap machine or the like. It is in.

An embodiment of a tap board embodying this invention will be described below with reference to the drawings.

Reference numeral 1 denotes a motor that can rotate in either forward or reverse directions and is attached to the machine frame (not shown) of the tap board, and 2 is a drive shaft that is drivingly connected to the motor 1 via a belt 3. A wide gear 4 is provided at approximately the middle position, and a worm 5 is provided at the lower end. 6 meshes the main shaft gear 7 attached to the upper end with the wide width gear 4;
It is a main shaft that is rotated, and a tap 9 for screw machining is attached via a tap chuck 8 provided at the lower end of the main shaft. 10 is a main shaft cylinder which rotatably supports the main shaft 6 and is movably supported in the axial direction with respect to the machine frame, and has a rack 11 on its outer surface.
is formed. Reference numeral 12 denotes a backflash removal spring interposed within the main shaft cylinder 10.

A worm wheel 13 meshes with the worm 5 of the drive shaft 2 and rotates the rotary shaft 16 via gears 14 and 15. 1
Reference numeral 7 denotes a cylindrical pinion shaft having a pinion 18 that meshes with the rack 11 of the main shaft cylinder 10, and is operatively connected to the rotating shaft 16 via a clutch device 19 that is released when excessive torque is applied. ing. Then, due to the forward rotation of the motor 1, the pinion shaft 17 is rotated in the counterclockwise direction in FIG. At the same time, the main shaft 6 is rotated in the forward direction to perform threading of the pilot hole 20a previously formed in the workpiece 20, and the main shaft cylinder 10 is moved upward (backward motion) by the reverse rotation of the motor 1.
At the same time, the main shaft 6 is rotated in the opposite direction to tap 9.
is extracted from the workpiece 20, and one machining cycle is completed.

Reference numeral 21 denotes a rotary disk fixed to the pinion shaft 17, and as shown in FIG. 2, a notch 22 for detecting the original position (the uppermost position of the tap 9) is formed at one location on its outer circumference. ing. 23 are located at positions with a center angle of 23.5° in the clockwise direction in FIG. A total of 48 detection holes are provided on the concentric circumference at angular intervals, and from the next 4th hole onwards, they are also provided on the concentric circumference at equal angular intervals with a center angle of 6.5°. Detect the amount of movement.

24 and 25 are the rotary disks 2 as shown in FIG.
A light emitting diode and a phototransistor are provided on both sides of the tap 9, and when the tap 9 is in the original position,
The phototransistor 25 is arranged at a relative position to receive light from the light emitting diode 24 through the notch 22. Reference numerals 26 and 27 are light emitting diodes and phototransistors provided on both sides of the rotary disk 21, which are arranged opposite to each other on the concentric circumference of the detection hole 23, and when the tap 9 is in its original position, the same light emitting diode and phototransistor are provided. The light emitting diode 26 and the phototransistor 27 are arranged to face each other at a location 10.5° closer to the base line L than the detection hole 23 closest to the base line L.

In this embodiment, the rotary disk 21 rotates so that the pitch of 6.5 degrees between the detection holes 23 corresponds to 1 mm of the downward or upward movement of the tap 9, and the phototransistor 27 intermittently turns on the light emitting diode 26. An arithmetic unit 41 (to be described later) calculates one pulse of a continuous pulse signal generated by sensing light as a tap movement amount of 1 mm.

In this embodiment, the three detection holes 23 on the side of the base line L are spaced at equal angular intervals of 4.5 degrees from positions spaced at a center angle of 23.5 degrees clockwise with respect to the base line L. When the tap 9 is in the original position, the light from the light emitting diode 26 is emitted randomly, and the reflected light is received by the phototransistor 27 through the detection hole 23 to prevent malfunction. , 48 holes 23 to be detected may be provided on a concentric circumference at equal angular intervals of 6.5 degrees from positions spaced apart by a center angle of 19.5 degrees on the clockwise side with respect to the base line L. In this case, the amount of movement of the tap 9 can be accurately detected from the first pulse when the tap 9 moves downward from its original position.

28 is a transfer device disposed below the tap 9 to send the workpiece 20 to the processing position of the tap 9, and includes a frame 29 and an index table 30 rotatably attached to the frame 29.
It is composed of. The index table 30 is intermittently controlled to rotate clockwise in FIG. 1 based on a control signal from an index table control circuit 46, which will be described later. Reference numeral 31 denotes eight clamps arranged concentrically on the top surface of the index table 30 at equal angular intervals. As the taps rotate, they are successively placed directly below the tap 9, that is, at the processing position. Therefore, the operator only needs to remove the workpiece 20 with the screw 20b set in the pilot hole 20a from the clamp 31, and then fix the workpiece 20 with the pilot hole 20a formed therein to the clamp 31.

Next, the operation panel attached to one side of the machine frame (not shown) of the tap panel will be explained based on Fig. 4.
is an emergency return switch located on the top of the operation panel 33, and by pressing this switch 32,
Even if the tap 9 is in the process of tapping, it can be immediately stopped and returned to its original position. 34 is a stroke setting dial disposed below the emergency return switch 32, and by setting the dial 34 to a predetermined scale 35, the tap 9 can be adjusted.
The forward movement amount is set. 36 is a code plate attached to the operating shaft 34a of the dial 34, as shown in FIG. It is composed of a preset counter that subtracts in advance the amount of movement that will overrun due to inertia when stopped at the (end of motion) position, converts it into a value that is converted into a binary code (BCD code) via contact 50, and is described later. The preset signal is input to the arithmetic unit 41 as a preset signal. That is, in this embodiment, when the overrun value of the tap 9 is set to 2 mm and the forward movement amount of the tap 9 is set to 40 mm by operating the stroke setting dial 34, the code plate 36
converts it to a 38mm value and converts it into a BCD code,
The code signal is inputted to an arithmetic unit 41, which will be described later, via a contact 50.

Reference numeral 37 denotes a mode changeover switch disposed below the stroke setting dial 34, which allows the operation of the tap board to be switched to an interlocking cycle, a single-action cycle, a fast-action cycle, and a processing cycle interlocked by an external start signal. It's getting old. 38 is a start switch provided below the mode changeover switch 37.

Next, an electric circuit for controlling the operation of the tap panel constructed as described above will be explained based on FIG.

41 inputs the pulse signal from the phototransistor 27, subtracts a preset value from the pulse signal, and converts the subtracted value (value converted to the amount of movement of tap 9) into a BCD cogo signal. It is an arithmetic unit that outputs data, and is composed of a preset counter. 42 is the arithmetic device 41
This is an input device for inputting a preset input signal to the stroke setting dial 34, the code plate 36, and the contact 50. Subtract the value in advance by the amount of movement to
It is converted into BCD code and set in the preset counter of the arithmetic unit 41. Therefore, if the forward movement amount of the tap 9 is set to, for example, 40 mm from the original position using the stroke setting dial 34,
Via the code plate 36 and the contact 50, the preset counter of the arithmetic unit 41 receives a movement amount of 38 mm, taking into account the overrun due to the inertia of the tap 9.
Since the BCD signal is input as a preset signal, the tap 9 moves forward and 38 pulse signals are generated from the phototransistor 27 (a detection signal that detects that the tap 9 has moved forward by 38 mm from its original position).
is input to the preset counter of the arithmetic unit 41, the preset counter subtracts the preset value and outputs a forward movement end signal based on the fact that the tap 9 has moved forward by 38 mm.

43 is a motor switching control device that outputs a forward/reverse drive command signal to a drive device 44 for forward/reverse drive of the motor 1 at the next stage based on the output signal from the arithmetic device 41; 45 is the motor switching control device 43; This is a timer circuit that operates with a reverse drive command signal from among the forward and reverse drive command signals from the controller, and outputs an activation signal after a preset certain period of time. The fixed time set in advance by this timer circuit 45 is
As shown in FIG. The time required for the tap 9 to completely escape from the surface of the workpiece 20 is set.

46 is an index table rotation control circuit that operates based on the operation signal from the timer circuit 45, and every time the operation signal is input, the rotation control circuit 46 rotates the index table 30 drive motor (not shown) in the transfer device 28. ) to rotate the index table 30 in the direction of the arrow shown in FIG.
It is designed to rotate intermittently by 45 degrees.

Next, the operation of the tap board constructed as described above will be explained.

Now, with the reciprocating amount of tap 9 being 40 mm, screw 2 into the prepared hole 20a of the workpiece 20 in the interlocking cycle.
When setting 0b, first set mode selector switch 3.
7 as the interlocking cycle, and set the stroke setting dial 34 to the scale 35 indicating "40". Then, the code plate 36 and the contact 50 cause the preset counter of the arithmetic unit 41 to read:
A 38 mm coded signal is preset that takes into consideration the overrun due to inertia when the tap 9 stops moving forward.

Next, when the start switch 38 is pressed to drive the motor 1, the tap 9 starts to rotate and move forward, and the turntable 21 starts to rotate as shown in FIG. Then, the phototransistor 27
receives the light from the light emitting diodes 26 arranged opposite each other through the detection hole 23, generates a pulse signal, and inputs the pulse signal to the preset counter of the arithmetic unit 41. Therefore, the preset counter controls the code plate 3 by this pulse signal.
The input preset values are sequentially subtracted from 6.

When the 38th pulse signal from the phototransistor 27 is input to the preset counter of the arithmetic unit 41, that is, when the tap 9 moves forward by 38 mm from its original position, the preset value of the preset counter is completely subtracted. 0, the calculation device 41 sends an output signal for motor reverse drive to the motor switching control device 43, and based on the output signal, the motor switching control device 43 outputs a reverse drive command signal, Switch the motor 1 from forward rotation drive to reverse rotation drive. At this time, the reversal time of the motor 1 is delayed due to the inertial force, and the tap 9 overruns downward. The set counter is displayed before tap 9 moves forward by 40mm (38
Since the output signal for driving the motor in the reverse direction is sent to the motor switching control device 43 at the next stage when the tap 9 is moved forward by 38 mm, the inertia force causes the tap 9 to move forward by 38 mm. 40mm as shown
It overruns to the machining end position, then reverses and starts double movement.

Therefore, tap 9 is the stroke setting dial 3.
After moving forward to the 40 mm set in step 4, it moves back from the end position of the forward movement, so accidents such as forming the screw hole too deep or damaging the tap 9 can be prevented.

Then, as shown in FIG. 7, when the backward-moved tap 9 completely comes out of the workpiece 20, a timer circuit starts operating based on a reverse drive command signal from the motor switching control device 43. 45 operates the index table rotation control circuit 46 to rotate the index table 30 by 45 degrees. Therefore, at the same time that the tap 9, which is moving back toward the original position for a continuous machining cycle, exits the workpiece 20, the next workpiece 20, for which the rotation of the index table 30 is started, will move downwards from the tap 9. As in the conventional machine, after the tap 9 moves back to the original position, until the workpiece is sent to the processing position by the transfer device, the next workpiece in the continuous cycle is It is possible to eliminate the lost time of waiting for the start of a machining cycle and increase production efficiency.

Note that this invention is not limited to the above-mentioned embodiment, and the value to be preset in the preset counter can be changed as appropriate in response to changes in the amount of overrun of the tap 9 due to the material of the workpiece or different processing processes. Or, it can be applied to all processing machines that have reciprocating motion, such as drilling machines other than tapping machines.
Any changes can be made without departing from the spirit of this invention.

As detailed above, according to this invention, the main spindle cylinder is reciprocated by subtracting the stroke that takes into account the overrun from the set stroke and outputting the result, so that it can be adjusted freely depending on the machining process. It is possible to accurately reciprocate stroke processing within a preset forward stroke range.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway perspective view of a tap board that embodies this invention, Figures 2 and 3 are front and side views of the rotary disc, Figure 4 is a front view of the operation panel, FIG. 5 is an explanatory diagram showing the relationship between the code plate attached to the stroke setting dial and the arithmetic unit, FIG. 6 is an electric circuit diagram, and FIG. 7 is an explanatory diagram showing the state of movement of the tap. Motor 1, tap 9, main shaft cylinder 10, pinion shaft 17, workpiece 20, rotary disk 21, detection hole 23,
Light emitting diodes 24, 26, phototransistor 2
5, 27, transfer device 28, index table 30, stroke setting dial 34, code plate 3
6, arithmetic device 41, input device 42, motor switching control device 43, timer circuit 45, index table rotation control circuit 46, contact point 50;

Claims (1)

[Claims for Utility Model Registration] A main shaft cylinder 10 rotatably supporting a main shaft 6 having a tool 9 attached to its tip and movably supported on a machine frame.
, a drive member 1 for reciprocating the main shaft cylinder 10 in its axial direction, and pulse generators 21 and 26 that generate pulses for each unit of movement of the main shaft cylinder 10 as it moves from its origin. , 27, a stroke setting member 34 for presetting the forward stroke of the main shaft cylinder 10, and a pulse number corresponding to the stroke set by the stroke setting member 34.
a stroke signal generating means 36 for outputting the stroke obtained by subtracting the number of pulses corresponding to the amount of movement based on inertia when the motor is stopped as a binary code value; Set counter 41
and a switching means 43 for generating a signal for switching the drive direction of the drive member 1 when the number of pulses generated from the pulse generators 21, 26, 27 reaches the number stored in the preset counter 41. Machine tools consisting of and.