JPS6316946A - Broken tool detecting device - Google Patents

Abstract

PURPOSE:To simplify the structure of a detecting device so as to decrease substantially its cost by installing a face plate, a face plate pressing means, an actuater, a limit switch, a check pin and a judging part in the detecting device for the broken tool remaining on the machined work. CONSTITUTION:When an actuater 22 is actuated from the state that a face plate 20 is in the regression end, a check pin 19 is displaced to a machined work 11 side by a face plate pressing means and if there is no trouble, the check pin 19 reaches smoothly to the portion to be machined 18 of the work 11 after the fixed time. However, in case the broken tool 26 remains in the portion to be machined 18, the check pin 19 abuts to the broken tool 26 and the advance of the face plate 20 is checked, as a result a limit switch 25 does not detect the advancing end of the face plate 20 even after the fixed time elapsed and a judging part judges that the broken too 26 remains in the work 11. Furthermore, when the face plate 20 regresses, the actuater 22 actuates inversely, thus the face plate 20 is pulled back to the frame side by a stopper 23 against a face plate pressing means.

Description

[Detailed description of the invention] <Industrial usage meter> The present invention relates to a tool breakage detection device that automatically determines whether or not a broken tool remains in a processed workpiece, and particularly relates to a tool breakage detection device that automatically determines whether or not a broken tool remains in a processed workpiece. This is intended to reduce costs.

<Conventional technology> When performing deep hole drilling or tapping continuously using various types of unmanned machine tools, tools often break due to tool fatigue, and in the worst case, breakage occurs. This results in a situation where the tool remains in the workpiece and subsequent machining becomes impossible.

In order to prevent problems like B, a tool breakage detection device is installed adjacent to the machine tool described above, which automatically determines the presence or absence of tools remaining in the machined part of the workpiece.

As shown in FIG. 2, which schematically shows the structure of an example of a conventional worker breakage detection device, a pair of guide bars 103 extending on a pedestal 102 in a direction facing a processed workpiece 101 include a pair of guide bars 103. A slider 105 is slidably held to support a pair of pilot bars 104 in a direction parallel to the slider. An actuator 106 attached to a pedestal 102 is connected to the slider 105 via a universal joint 107, and the forward and backward ends of the slider 105 relative to the workpiece 101 are connected to a pair of limit switches 108 attached to the pedestal 102. , 109. Said pilot par 1
A face plate 112 integrally protrudes from the tip of 04 with a check bin 111 that can be fitted into the machined hole 110 of the workpiece 101.
is fixed, and a compression spring 113 is interposed between the face plate 112 and the slider 105 to constantly press the face plate 112 toward the workpiece 101. And this compression spring 113
A limit switch 114 is provided on the slider 105 to detect the backward displacement of the face plate 112 against the spring force.

Therefore, the slider 1 due to the actuation of the actuator 106
When the check bin 111 comes into contact with the broken tool 115 during the forward movement of the workpiece 101, the forward movement of the face plate 112 is blocked and the limit switch 114 is pressed.
It can be confirmed that 15 remains.

<Problems to be Solved by the Invention> The conventional tool breakage detection device shown in FIG.
, 1.14, the number of parts is large and the structure of the device tends to be complicated. Also, slider 10
Since the face plate 112, compression spring 113, and limit switch 114 are moved together with the actuator 5, it is necessary to use a high-performance actuator 106, which is unfavorable in terms of weight and cost.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the conventional tool breakage detection devices, it is an object of the present invention to provide a tool breakage detection device that has a simple structure and is advantageous in terms of cost.

Means for Solving Problems> The tool breakage detection device according to the present invention includes a face plate that faces a processed workpiece and is held on a pedestal so as to be slidable in the opposite direction, and a gap between the face plate and the pedestal. and a drawing board pressing means that is interposed in the base plate and elastically presses the face plate toward the processed workpiece, and a rod that is provided on the pedestal and slidably penetrates the face plate, and that is latched to the face plate. an actuator in which a stopper is formed at the tip of the rod to restrict displacement of the face plate toward the processed work; and a pair of limit switches that respectively detect a forward end and a retreat end of the face plate with respect to the processed work. a check bin that is integrally provided on the face plate and that can come into contact with a broken tool that is fed into the machining part of the machined workpiece and remains in the machining part; and a determining unit that determines that the broken tool remains in the processed workpiece when the broken tool does not move to the forward end.

Function: When the actuator is operated with the face plate at the retreat end, the check bin is displaced toward the machined workpiece by the face plate pressing means, and if there is no abnormality, the check bin moves to the machined part of the workpiece after a certain period of time. reach as it is. However, if a broken tool remains in this machined part,
As a result of the check bin coming into contact with this broken tool and preventing the face plate from moving forward, the limit switch will not detect the forward end of the face plate even after a certain period of time has passed, and the broken tool will remain on the workpiece in the determination section. It is determined that there is.

Furthermore, when the face plate is retracted, the actuator operates in the opposite direction.
The face plate is pulled back toward the mount by the stopper against the face plate pressing means.

<Embodiment> As shown in FIG. 1, which shows a schematic structure of an embodiment of the tool breakage detection device according to the present invention, a single-acting air cylinder 13 is mounted on a pedestal 12 facing a processed workpiece 11. A check valve 14 with a variable throttle and a quick exhaust valve 15 are installed between these air cylinders 13 and an air supply source (not shown) that supplies compressed air to the air cylinders 13.
and a pressure reducing valve 16 are interposed in series. The work 1
At the tips of the plungers 17 of these air cylinders 13 that slide in the direction opposite to the workpiece 11, there is a face plate 20 protruding from a check pin 19 that can be fitted into a machined hole 18 formed in the workpiece 11.
is integrally fixed. The mount 12 has a face plate 2.
An actuator 22 equipped with a piston rod 21 that slidably passes through the air cylinder 13 is installed so as to be located between the pair of air cylinders 13. At the tip of the piston rod 21 parallel to the plunger 17, A stopper 23 is provided to restrict displacement of the face plate 20 toward the workpiece 11 due to the operation of the air cylinder 13.

Further, a pair of limit switches 24 and 25 are fixed to the frame 12 on the sides of the face plate 20 for regulating the operating range of the actuator 22 and setting the forward end and the backward end of the face plate 20.

Compressed air is always supplied to the air cinder 13,
The amount of protrusion toward the workpiece 11 is regulated by the stopper 23 of the actuator 22, and in the initial state, the face plate 20 is in contact with the limit switch 24, and the face plate 20 is located at the backward end. From this state, actuator 22
When the piston rod 21 starts to move forward toward the work 11, the face plate 20 moves together with the plunger 17 and the piston rod 21 due to compressed air from the air cylinder 13.

If the broken tool 26 does not remain in the machined hole 18, the face plate 20 moves away from the limit switch 24, and after a certain period of time, the limit switch 25 is pressed and the machined hole 28 is pressed.
The check bin 19 fits inside. Due to the ON operation of this limit switch 25, the judgment section (not shown)
is in a normal state.

On the other hand, if the broken tool 26 remains in the machined hole 18, the check bin 19 comes into contact with the broken tool 26 while the face plate 20 is moving forward, and the forward movement of the face plate 20 is blocked. but,
The piston rod 21 of the actuator 22 continues to move forward relative to the face plate 20, and even after a certain period of time has elapsed since the face plate 20 has separated from the limit switch 24, the limit switch 25 remains open.
Not N. In this case, the determination unit determines that the work 11 is in an abnormal state. That is, the determination section has a structure in which it is electrically connected to the limit switches 24 and 25 and includes a built-in timer. Note that when the forward movement of the face plate 20 is blocked, the compressed air from the air supply source is discharged through the quick exhaust valve 15.
=8- is exhausted from the outside. Further, in this embodiment, the air cylinder 13 or the like is used as the face plate pressing means, but if the front and rear stroke of the face plate 20 does not need to be too large, a compression spring may be interposed between the face plate 20 and the pedestal 12. It is also possible to use this as a face plate pressing means.

<Effects of the Invention> According to the tool breakage detection device of the present invention, it is sufficient to have two plungers corresponding to a guide bar or a piston bar, and a pair of limit switches are also provided. Moreover, since the main movable part is only the face plate, the mechanism is simpler and the capacity of the actuator can be smaller than conventional ones, and it is possible to significantly reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a mechanism showing a schematic structure of an embodiment of a tool breakage detection device according to the present invention, and FIG. 2 is a conceptual diagram of a mechanism of a conventional example thereof. Also, in the figure, 11 is a machined workpiece, 12 is a frame, 13 is an air cylinder, 17 is a plunger, 18 is a machined hole, 19 is a check pin, 20 is a face plate, 21 is a piston rod, 22 is an actuator, 23 is a stopper, 24
．． 25 is a limit switch, and 26 is a broken tool.

Claims (1)

[Claims] A face plate that faces the processed workpiece and is held on a pedestal so as to be slidable in the opposite direction; and a face plate that is interposed between the face plate and the pedestal and elastically presses the face plate toward the processed workpiece side. A stopper, which has a face plate pressing means and a rod provided on the mount and slidably penetrates the face plate, and which locks on the face plate and restricts displacement of the face plate toward the processed workpiece, is provided on the rod. an actuator formed at the tip, a pair of limit switches for respectively detecting forward and backward ends of the face plate with respect to the machined workpiece, and an actuator integrally protruding from the face plate to process the machined part of the machined workpiece. a check pin that can come into contact with a broken tool that is sent into the machined part and remains in the machined part; and a check pin that can come into contact with a broken tool that remains in the machined part when the face plate does not move from its retreating end to its forward end within a certain period of time, and the broken tool remains in the machined workpiece. A tool breakage detection device comprising a determination unit that determines.