JPS6355427B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a machine tool that processes a workpiece by rotating and reciprocating a tool relative to the workpiece.

Conventional technology Machine tools such as drill presses and lathes have been equipped with a function to display the amount of cutting resistance applied to the tool during machining.
-There is one shown in Publication No. 139290. According to this configuration, the display device emits light in stages according to the load condition applied to the processing tool, so that the resistance is displayed in stages.

However, with this configuration, only the load condition applied to the processing tool can be determined, and even if the type of processing tool or processing method is changed, it cannot be determined whether the processing tool is being operated in the optimal condition. Nakatsuta.

Purpose The purpose of the present invention is to solve the above-mentioned problems by displaying the ratio of the cutting force actually applied to the tool to the cutting force, which is a standard that is reset according to the processing method of the workpiece. Therefore, it is an object of the present invention to provide a machine tool that can perform machining work efficiently and safely by operating the tool in an optimal state.

Embodiment Hereinafter, an embodiment in which the present invention is embodied in a drilling machine will be described based on the drawings.

In FIG. 1, a drive shaft 1a of a three-phase induction motor (hereinafter referred to as motor) 1 as a rotational drive device is drivingly connected to a spline shaft 2 via a rotation transmission member (not shown). The rotational force is transmitted to the spline shaft 2. The torque detection device 3 as a cutting resistance detection device detects the driving torque applied to the spline shaft 2, and in this embodiment, as shown in Japanese Patent Application No. 55-151645, the torque detection device 3 detects the driving torque applied to the spline shaft 2. The drive torque is determined by detecting the amount of twist of the rotation transmission member transmitted to the rotation transmission member 2 using a photocoupler (not shown).

A drill 6 as a tool is attached to the tip of the main shaft 4 via a chuck 5, and a cylindrical portion 7 is provided at the base end to which the spline shaft 2 is fitted so as to be movable only in the axial direction. The main shaft cylinder 8 is the main shaft 4
rotatably and immovably supported in the axial direction,
A piston 9 is attached to its outer periphery. The air cylinder 10 has the piston 9 inserted therein to constitute a reciprocating drive device, and a first
An air cylinder chamber 11 and a second air cylinder chamber 12 are provided.

The electromagnetic valve 13 is switched and controlled by an electric control circuit described later, and supplies air from the air pump 14 to the first air cylinder chamber 11 and to the second air cylinder chamber 1.
When the second air is discharged by the silencer 15, it is moved forward by the piston 9, that is, the main shaft cylinder 8, and conversely, the air from the air pump 14 is discharged from the second air cylinder chamber 1.
2, and when the air in the first air cylinder chamber 11 is discharged by the silencer 15, the main shaft cylinder 8 is moved back. Therefore, the drill 6 is given a rotational force by the motor 1, and is reciprocated by switching the electromagnetic valve 13.

The drilling operation using this drilling machine is performed as follows. That is, as shown in FIG. 2, first, the drill 6 located at the origin position P0 moves forward toward the workpiece M while rotating, and drilling and cutting is started. When cutting is performed to a predetermined depth D, that is, to the end of machining, the drill 6 moves back to the origin position P0 and the drilling operation is completed.

Next, an abnormality detection means for detecting whether the main parts of the drilling machine such as the torque detection device 3 are operating normally will be explained.

A motor abnormal overheat detection device (hereinafter referred to as abnormal overheat detection device) 16 is comprised of a temperature sensing element such as a thermal relay, and is installed inside the motor 1, and when the motor 1 is overheated to a permissible temperature or higher,
Abnormal overheating signal SG1 that changes from zero potential (hereinafter referred to as L level) to positive potential (hereinafter referred to as H level)
Output. The abnormal torque operation detection device 17 is attached to the torque detection device 3, and when the torque detection device 3 is not operating normally, the abnormal torque operation signal SG2 changes from L level to H level.
Output. Although there are various conventional methods for torque detection, the torque detection device 3 of this embodiment detects the amount of twist of a rotating member using a photocoupler as described above, and uses a counter to output a pulse signal from the photocoupler. (not shown), so in this embodiment, it is determined whether the torque detection device 3 is operating normally or not when the light emitting diode of the photocoupler normally emits light. This is done by checking whether there are any. When the light emitting diode is not emitting light normally, the H
A level torque abnormal operation signal SG2 is output.

The pressure abnormality detection device 18 is a pressure switch and is attached to the air pump 14, and when the air pump 14 is abnormally driven, the air cylinder 10 is
When the pressure of the air supplied to the air drops to, for example, 5 kg/m ² or less, an H-level pressure abnormality signal SG3 is output. The origin position detection device 19 is composed of a photocoupler, a micro switch, etc.
When the motor is at the home position P0, a driven rod (not shown) provided on the main shaft cylinder 8 acts to output a home position signal SG4 of H level. The machining end detection device 20 is composed of a photocoupler, a micro switch, or the like, and when the drill 6 reaches the machining end end (when it has moved forward to a preset required depth D), the following action is performed by the driven rod. An H level end position signal SG5 is output.

Next, a control circuit for driving and controlling the drilling machine constructed as described above will be explained with reference to FIG.

In FIG. 3, a central processing unit (hereinafter referred to as CPU) 21 as a control means has a read-only program memory (hereinafter referred to as ROM) in which program data for controlling the drilling machine and other various data are stored. )22
and a readable and writable memory (Random Access Memory; hereinafter referred to as RAM) for storing data of the driving torque applied to the main shaft 4.
Together with 23, it constitutes an arithmetic and control device. and. Each time the drill 6 makes one revolution, the CPU 21 reads out the current driving torque value [T] from the torque detection device 3 via the I/O port 24, and stores it in a predetermined address of the RAM 23. The CPU 21 also includes the abnormal overheating detection device,
Each detection device 16 to 2 such as a torque abnormal operation detection device
Each of the signals SG1 to SG5 output from the I/O port 24 is inputted through the I/O port 24.

A start switch 25 is provided at a predetermined location on the drilling machine, and when the switch 25 is pressed, a start signal SG6 is sent to the CPU 2 via the I/O port 24.
1 is output. The abnormal cutting resistance value setter 26 is provided at a predetermined location of the drilling machine, and can be operated by an operator to appropriately set the maximum allowable resistance reference value [X1] of the cutting resistance applied to the drill 6 used in the drilling machine. and outputs the set resistance reference value [X1] to the CPU 21. A reset switch 32 is provided at a predetermined location on the drilling machine, and by pressing the switch 32, a reset signal SG is activated.
7 is output to the CPU 21 via the I/O port 24. The CPU 21 then returns to its initial state in response to the reset signal SG7.

The motor drive circuit 27 is configured to drive and control the motor 1 based on a drive control signal output from the CPU 21 via the I/O port 28. Valve drive circuit 29 is I/O
Based on the drive control signal output from the CPU 21 through the port 28, the electromagnetic valve 13
The drill 6 is configured to switch and control the drill 6.
to move forward and backward.

The display device 30 consists of ten indicators 30a to 30j arranged at predetermined locations on the drilling machine, and these indicators 30a to 30j are controlled based on drive control signals output from the CPU 21 to the display drive circuit 31. The lighting and blinking display is controlled.

Next, the operation of the drilling machine constructed as described above will be explained with reference to flowcharts of the arithmetic processing operations of the CPU 21 shown in FIGS. 4 and 5.

Now, when a power switch (not shown) is turned on with the drill 6 in its original position, the CPU 21 executes arithmetic processing operations according to the flowchart shown in FIG. The CPU 21 performs arithmetic processing operations according to the diagnostic subroutine (see FIG. 5), and checks the presence or absence of H level signals SG1 to SG5 output from each of the detection devices 16 to 20, such as the abnormal overheating detection device. That is, the air pump 1
4 does not operate normally and the pressure of the air supplied to the cylinder 10 has decreased.
8 detects the H level pressure abnormal signal SG3.
When outputting to the CPU 21, the CPU 21 outputs a drive control signal to the display drive circuit 31 and outputs a drive control signal to the display device 3.
Only the display 30a at the left end of 0 is made to blink.
Subsequently, the CPU 21 outputs a return control signal and a stop control signal to the valve drive circuit 29 and the motor drive circuit 27, respectively, to move the drill 6 back to the home position P0 and stop the rotation of the motor 1, and maintain that state. Hold.

Further, when the abnormal overheating detection device 16 detects that the motor 1 has reached an overheating temperature higher than the permissible level and outputs an abnormal overheating signal SG1 of H level to the CPU 21, the CPU 21 outputs a drive control signal to the display drive circuit 31. and blinks only the second display 30b from the left side of the display device 30,
Similarly to the above, the drill 6 is moved back to the origin position P0 and the motor 1 is stopped.

Further, the abnormal torque operation detection device 17 detects that the torque detector 3 is not operating normally, and sends an H level torque abnormal operation signal SG2 to the CPU.
21, the CPU 21 causes the display drive circuit 31 to output a drive control signal to blink only the third display 30c from the left side of the display device 30, and returns the drill 6 to the origin position P0 in the same manner as above. and stop the motor 1.

Further, one or both of the origin position and machining end detection devices 19, 20 malfunctions, and both devices 19, 20 simultaneously output H level origin position and end position signals SG4, SG5 to the CPU 21. Then, the CPU 21 outputs a drive control signal to the display sum drive circuit 31 to blink only the fourth display 30d from the left side of the display device 30, and moves the drill 6 to the origin position P in the same manner as above.
0 and stop the motor 1.

If there is no abnormality as a result of the execution of this diagnostic subroutine, the CPU 21 then determines whether the drill 6 is at the home position P0 using the H level home position signal SG4 output from the home position detection device 19. Judgment based on presence/absence, drill 6
is not at the home position P0, the CPU 21 outputs a display control signal to the display drive circuit 31 to blink only the fifth display 30e from the left side of the display device 30, so that the operator can move the drill 6 to the home position P0.
0 and executes the arithmetic processing operation according to the diagnosis subroutine again. However, when the drill 6 is at the origin position P0, the CPU 2
1 waits for the activation signal SG6 from the activation switch 25.

When the worker presses the start switch 25, the start signal is activated.
SG6 is output to CPU21. The CPU 21 executes the diagnostic subroutine in response to the start signal SG6, checks whether the motor 1, the torque detection device 3, etc. are operating normally, and then sends the motor drive circuit 27 to drive the motor in the forward direction. A control signal is output to start the motor 1. When the motor 1 starts, the CPU 21 again executes the diagnostic subroutine to check whether the motor 1, the torque detection device 3, etc. are operating normally, and then outputs a forward movement control signal to the valve drive circuit 29. to control the switching of the solenoid valve,
The drill 6 is moved forward from the origin position P0 to the processing position.

When the drill 6 starts moving forward, the CPU 21 executes the diagnostic subroutine again and checks each detection device 16 to
20, the drive torque value [T0] in the no-load state at the start of forward movement is read out from the torque detection device 3 and stored at a predetermined address in the RAM 23. Subsequently, after executing the diagnostic subroutine again, the CPU 21 reads out the driving torque value [T] at that time from the torque detection device 3 in order to obtain the cutting force [Tx] applied to the drill 6 for each rotation, and stores it at a predetermined address in the RAM 23. The cutting force applied to the drill 6 [Tx (=T-
T0)] is calculated.

Next, the CPU 21 executes the diagnostic subroutine again, and then compares the cutting resistance [Tx] applied to the drill 6 for each rotation with the resistance reference value [X1] read from the abnormal cutting resistance value setter 26. ,
At this point, the cutting force [Tx] is the reference value [X1].
When it is smaller, the CPU 21 executes the diagnostic subroutine again, and then the resistance reference value [X1]
The ratio (hereinafter referred to as resistance ratio) [θ%] of the cutting resistance [Tx] obtained above to the above-determined cutting resistance [Tx] is calculated. and,
The CPU 21 outputs a display control signal to the display drive circuit 31 based on this resistance ratio [θ%], and
A number corresponding to the internal resistance ratio [θ%] of the indicators 30a to 30j are turned on sequentially from the indicator 30a side.

Therefore, when the resistance ratio [θ%] is 30%, the three indicators 30a, 30b, and 30c light up, and when it is 60%, the six indicators from display 30a to display 30f light up. pcs lights up. In this embodiment, if the resistance ratio [θ%] is 30%, for example, and the first digit has a value of "1" to "9", all values are rounded down to 30%, and the display 30a From display 3
The three 0c lights are displayed.

After displaying the resistance ratio [θ%] of the cutting force [Tx] applied to the drill 6 at that time on the display device 30, the CPU 21 executes the diagnostic subroutine again. Subsequently, the CPU 21 determines whether the drill 6 has moved forward and reached the end of machining. That is, the CPU 21 detects the machining end end detecting device 20.
The presence or absence of the H-level end position signal SG5 is checked, and if there is no H-level end position signal SG5, it is determined that the cutting process has not yet been completed, and the cutting force applied to the drill 6 in the same manner as above. Tx], determines whether the cutting force [Tx] is greater than the resistance reference value [X1], and displays the resistance ratio [θ%].

Thereafter, the CPU 21 repeats the above calculation processing operation until the cutting process is completed. Therefore, the lighting of the display device 30 is controlled by the CPU 21 based on the resistance ratio [θ%] of the cutting force [Tx] at any given time during cutting to the resistance reference value [X1], and the operator can now It is possible to easily know what ratio the cutting resistance [Tx] applied to the drill 6 is to the resistance reference value [X1].

When the cutting of the workpiece M is completed and the drill 6 moves forward to the machining end position, the machining end detection device 20 outputs an H level end position signal SG5. The CPU 21 outputs a backward movement control signal to the valve drive circuit 29 based on this end position signal SG5, and immediately moves the drill 6 back toward the origin position P0. When the drill 6 is returned to the home position P0, the CPU 21 outputs a stop control signal to the motor drive circuit 27 in response to the home position signal SG4 at the H level output from the home position detection device 19 to start the motor. Stop the rotation of 1. Then, preparation is made for cutting the next workpiece M.

On the other hand, when the cutting resistance [Tx] applied to the drill 6 during cutting becomes larger than the resistance reference value [X1], the CPU 21 displays the indicators 30a to 30j.
are all blinking, and a double-motion control signal is immediately output to the valve drive circuit 29 to return the drill 6 to the home position P0, and a stop control signal is output to the motor drive circuit 27 to stop the rotation of the motor 1. make it stop. Therefore, drill 6
will not break during cutting and can be processed safely. In addition, the display device 30a~
The blinking display 30j is completely turned off by pressing the reset switch 32. Further, when an abnormal signal is output from one of the detection devices 16 to 20 during cutting, for example, if the torque detection device 3 is not operating normally, the CPU 21 follows the diagnostic subroutine shown in FIG. Vessels 30a-30J
Displays 30a to 3 corresponding to the abnormal location are displayed so that the third display 30c from the left in the display blinks.
0d is displayed blinking, the drill 6 is moved back to the origin position P0, and the motor 1 is stopped. Therefore, the operator can immediately perform maintenance work at the location corresponding to the blinking display on the indicators 30a to 30d. After the maintenance work has been performed, the reset switch 32 is pressed and the display 30
A to 30d are turned off.

In this embodiment, the cutting resistance [Tx] applied during cutting is expressed as a ratio [θ%] to a preset resistance reference value [X1] on the display 3.
Since it is expressed by the number of lights from 0a to 30j, the operator can easily know what percentage of the cutting resistance [Xx] currently being applied to the drill 6 is with respect to the resistance reference value [X1]. can.

By doing this, you can check whether the drill 6 during cutting is working in an inefficient state (when the cutting resistance is displaying a value close to the set resistance reference value).
Or, you can know whether you are working in an efficient state (when the cutting force is displaying a value much lower than the set resistance reference value), which not only improves work efficiency, but also improves drilling efficiency. 6
You can immediately determine the cause of poor cutting.

Also, during cutting and before starting machining, the CPU 21 checks whether the rotation drive device of the motor 1, the forward drive device of the drill 6, or the detection device are operating normally, and if any abnormality occurs, Drill 6 regardless of whether cutting is in progress or not.
immediately return to the home position P0, and motor 1
and 10 indicators 30a to 3.
0j, the display corresponding to the detecting device in which the abnormality occurred is displayed blinking, so that machining work can be performed safely and maintenance work can be performed easily and quickly.

In addition, the CPU 21 checks that the detection device etc. are operating normally before performing drive control and calculation processing operations such as when starting the motor 1, when the drill 6 moves back, and when calculating the cutting resistance [Tx]. Since the arithmetic processing operation is performed to check whether or not the machine is present, the drive control and the arithmetic processing operation described above are executed accurately and reliably, so that the machining work can be performed safely.

Further, the display device 30 not only displays the ratio of the cutting force applied to the drill 6 during the cutting process to a preset value, but also displays the ratio when an abnormality signal is generated by the abnormality detection means. Instead, since a display corresponding to the abnormal location is displayed, one display device 30 can display two functions, which not only simplifies the configuration of the display device 30 but also makes the entire display device 30 inexpensive and compact. can be taken as a thing.

Note that the present invention is not limited to the embodiments described above; for example, in the embodiments described above, when two or more items do not operate normally, only the display corresponding to the one whose abnormality was detected earlier is displayed. flashes,
Although the indicators corresponding to the other items are designed not to blink, it is possible to make both of them blink, or to stop the tool 6 without making a double movement when an abnormality is detected. Any changes may be made without departing from the spirit of the invention.

Effects As detailed above, according to the present invention, a single display device is provided, and this display device shows the cutting force actually applied to the tool relative to the cutting force that serves as a reference for resetting according to the processing method of the workpiece. By displaying the display according to the ratio, not only can the processing tools be operated in the optimal condition and machining work can be performed efficiently and safely, but also if there is an abnormality with the machine tool, it can be corrected. By displaying the abnormal location instead of the above display, inspection work is facilitated, and the entire display device can be made inexpensive and compact.

[Brief explanation of drawings]

Fig. 1 is a mechanical diagram showing the mechanism of a drilling machine embodying this invention, Fig. 2 is an operation diagram showing the operation of the drill of this invention, Fig. 3 is an electric block circuit diagram,
FIGS. 4 and 5 are flowcharts for explaining arithmetic processing operations of the central processing unit. Three-phase induction motor 1 as a rotational drive device, torque detection device 3 as a cutting resistance detection device, main shaft 4, drill 6 as a tool, main shaft cylinder 8, piston 9 as a reciprocating drive device, air cylinder 10, electromagnetic valve 13 , air pump 14, motor abnormal overheat detection device 16 as abnormality detection means, abnormal torque operation detection device 17, pressure abnormality detection device 18, origin position detection device 19, machining end detection device 20, central processing unit 21 as control means , an abnormal cutting resistance value setting device 26 as a setting device, a display device 30, display devices 30a to 30j as display sections, and a workpiece M.

Claims (1)

[Claims] 1. A rotary drive device 1 for applying rotational force to the tool 6, and a reciprocating drive device (9, 10, etc.) for relatively reciprocating the tool 6 toward the workpiece M. A machine tool comprising: a cutting resistance detection device 3 provided between the rotary drive device 1 or the tool 6 and for detecting cutting resistance applied to the tool 6 based on a change in drive torque; and the workpiece. a setting device 26 for setting a standard cutting resistance value according to the machining method of M; the rotary drive device 1, the reciprocating drive device (9, 10
etc.) and the detection section of the cutting resistance detection device 3, etc., to detect whether they are operating normally or not, and to generate an abnormal signal when they are not operating normally. Anomaly detection means (1) for
6, 17, etc.), the magnitude of the cutting resistance detected by the cutting resistance detection device 3 is compared with the value set by the setting device 26, and the cutting resistance detected by the cutting resistance detection device 3 is compared with the value set by the setting device 26. When the value becomes larger than the value set by the setting device 26 and when an abnormality signal is generated by the abnormality detection means (16, 17, etc.), the relative forward motion of the tool 6 toward the workpiece M is stopped;
Alternatively, a control means 21 for controlling the reciprocating drive device (9, 10, etc.) so that the tool 6 moves away from the workpiece M, and the cutting resistance at least during the reciprocating movement of the tool 6 toward the workpiece M. Display is performed according to the ratio of the cutting resistance detected by the detection device 3 to the value set by the setting device 26, and when the abnormality detection means (16, 17, etc.) generates an abnormal signal, the ratio is displayed. A machine tool comprising a single display device 30 for displaying a display corresponding to an abnormal location instead of displaying the corresponding display.