JPS6147654B2 - - Google Patents

Description

Detailed Description of the Invention The present invention is applicable to cases where there is a risk of a rotating tool being heavily worn or breaking during machining work, or when a rotating tool approaches a workpiece or other object and comes into contact with it. Ultrasonic vibrations with high frequencies are detected as a signal to notify abnormal or specific conditions of the rotating tool, and are used to replace the tool or take appropriate tool protection actions to prevent breakage. This invention relates to a tool adapter for extracting sound wave signals.

In recent years, with the advancement of production technology, the demand for labor-saving and unmanned cutting processes has rapidly increased.In such automatic machining, it is necessary to detect abnormal conditions such as damage or breakage of cutting tools in-process. This is an important issue.

One effective method for in-process detection of abnormal conditions such as cutting tool damage or breakage is to detect ultrasonic vibrations including acoustics and emissions caused by tool damage, breakage, or overload. A method has been put into practical use that uses detection signals to prevent tool damage and breakage, or to reduce the occurrence of overload. For example, the patent application 1983-
No. 069354 proposes a tool breakage prevention device using the above method.

The above-mentioned tool breakage prevention device includes means for generating elastic waves (ultrasonic waves) of a certain level or higher in response to an overload applied to a tool during cutting, which may cause the tool to break. A detector is installed in the tool holder or spindle head, receives the elastic waves generated by the means externally, distinguishes them from noise, and generates an output, and issues an alarm based on the output signal from the detector. The torque limiter is configured to perform a protective operation, and as a means for generating the above-mentioned elastic waves, a torque limiter that generates a relatively large level of elastic waves when activated is convenient and also serves as a protective operation for the tool, so it is preferable. An embodiment is shown in which a torque limiter is incorporated in the rear end of the tool holder.

When applying the above method to detecting and preventing breakage of a rotating tool, it is necessary to extract and detect ultrasonic vibrations (elastic waves) generated due to damage, breakage, or overload of the rotating tool. Conventionally, for example, in the above-mentioned tool breakage prevention device, detection was performed using an ultrasonic sensor attached to a fixed part of the machine tool body, but the ultrasonic vibration as a detection signal is transmitted between the rotating machine main shaft and the fixed part of the machine body. Since the information is transmitted to the sensor via a bearing installed in the machine, there is an inconvenience that in addition to attenuation when passing through the bearing, noise generated in the bearing is mixed in. Also, due to the gap between the machine main shaft and the machine fixed part, There was a problem in that the ultrasonic vibrations were attenuated and signal transmission was likely to become unstable. In particular, in the case of small-diameter rotary tools, the ultrasonic vibrations that normally occur when the tool breaks or is damaged are small, so it is not only difficult to distinguish it from noise, but also the gap between the machine spindle and the fixed part of the machine body. It has been extremely difficult to reliably detect ultrasonic vibrations as a signal.

The present invention was made with the aim of solving the above-mentioned problems, and it is possible to reliably detect ultrasonic vibrations generated in a rotating member such as a rotating rotary tool or a tool holder that moves with the rotating tool as a detection signal. A tool adapter that can be taken out is provided.

The basic principle of the present invention is to take advantage of the property that a thin liquid film transmits ultrasonic vibrations well, and this is because it utilizes the property that a thin liquid film transmits ultrasonic vibrations well. By forming a thin liquid film on the rotating member, the ultrasonic vibrations from the rotating member are transmitted to the adapter body with almost no attenuation, and can be detected by an ultrasonic sensor attached to the adapter body or the fixed part of the machine body. It is.

The means of the present invention taken to achieve the above object are as follows.

(a) It has an adapter body provided with a liquid supply port, and a rotary cylindrical body that holds a rotary tool that is rotatably supported through the adapter body.

(b) The adapter body is provided with a liquid supply passage that communicates from the liquid supply port to the supporting portion of the rotary cylindrical body.

(c) An ultrasonic sensor is attached near a fixing part of the adapter body or a machine body that fixes the adapter body.

(D) During operation, the adapter body is fixed to a fixed part of the machine body, and liquid is supplied from the liquid supply port through the liquid supply passage to form a thin oil film on the supporting part, and the adapter body is attached to the rotary tool or It is configured such that ultrasonic vibrations generated in a rotating member such as an interlocking tool holder are transmitted from the rotating cylindrical body to the adapter body through the liquid film.

Therefore, according to the present invention, ultrasonic vibrations generated in a rotating member such as a rotating tool or a tool holder linked thereto during operation are transmitted from the rotating cylindrical body through the liquid film to the adapter with almost no attenuation. By transmitting the information to the main body, the ultrasonic sensor can be reliably detected, and there is no risk of being affected by noise or the gap between the rotating part of the machine body (main shaft, etc.) and the fixed part of the machine body. . Therefore, the above-described tool breakage prevention device can be effectively applied to small-diameter rotary tools, and can also be used satisfactorily in noisy industrial machines and environments.

Note that if the thickness of the liquid film becomes too thin, the ultrasonic vibrations generated as noise due to shearing of the liquid film will become larger. According to experiments, it has been found that the thickness of the liquid film is preferably 0.2 mm to 0.4 mm. Further, if the liquid film thickness changes greatly during the work, the degree of attenuation of the ultrasonic vibrations to be transmitted and the degree of noise generation will change, which is undesirable. Therefore, it is necessary to firmly and reliably fix the adapter body to the fixed portion of the machine body, and to also provide rigidity to the adapter body. Furthermore, if the liquid leaks or changes in quality due to long-term operation, the degree of attenuation of ultrasonic vibrations and noise generation will change as described above, and the liquid will need to be replenished.

Embodiments of the present invention will be described below based on the drawings. The adapter body 1 includes a cylindrical portion 2 and a cylindrical portion 2.
It has an arm part 3 integrally protruding from the outside of the
A connecting portion 4 that protrudes laterally in parallel with the axis of the cylindrical portion 2 is connected to the lower side of the arm portion 3 . A fuel filler port 5 is provided at the lower end of the arm portion 3. A tapered fitting hole 6 is formed in the connecting portion 4, and a locking groove 7 is provided at the outer lower part.

A rotating cylindrical body 8 is rotatably supported in the cylindrical portion 2 of the adapter body 1 in a penetrating state. Rotating cylindrical body 8
The side wall plates 10, 10 have a flange 9 protruding from the outer periphery of the main part, and are fitted and fixed to openings on both sides of the cylindrical part 2.
The side wall plates 10 are sandwiched between the flanges 9 from both sides and prevented from moving in the axial direction.
It is rotatably supported in hole surfaces 11, 11 of 10. The rotating cylindrical body 8 is formed into a bottomed cylindrical body having a bottom portion 12, and the tool holder 1 inserted from the tip opening.
3 is fixedly held by a key 14 and a set screw 15. A rotary tool 16 such as a drill is attached to the tool holder 13, and the rotary tool 16 is attached to the rear end.
A torque limiter 17 is incorporated which operates when an overload is applied to the motor.

A holder 18 having a taper shank that is detachably connected to the main shaft 42 of the machine tool is fitted into the protrusion at the rear end of the rotary cylindrical body 8 . The holder 18 has a grip 19, and a drive key 43 is attached to the grip 19.
A keyway 20 that engages is provided. The holder 18 is connected to the bottom part 12 of the rotary cylindrical body 8 via a connecting bolt 21, and transmits the rotational force of the main shaft 42 to the rotary cylindrical body 8 via a steel ball 22, and rotates the rotating body mounted on the tool holder 13. Rotate the tool 16. In addition, a sphere 23 is interposed at an appropriate location of the fitting contact portion between the rotary cylindrical body 8 and the holder 18 to minimize the contact area between the two, and the machine tool body 40 and the bearing 4
4, the main shaft 42, etc., and harmful ultrasonic vibrations that become noise are difficult to be transmitted to the rotating cylindrical body 8.

On the other hand, passages 25 and 26 communicating with the fuel filler port 5 are bored in the adapter body 1 . The passage 26 is connected to the side wall plate 1 through two through holes 27, respectively.
The hole surface 11 and the rotary cylindrical body are connected to each other through a through hole 29 that communicates with the annular groove 28 provided on the outer peripheral surface of the side wall plate 10 and passes through the annular groove 28 and penetrates from the outer peripheral surface of the side wall plate 10 to the hole surface 11. An oil supply passage is formed which communicates with the rotary contact portion with the rotating cylindrical body 8, that is, the support portion of the rotary cylindrical body 8, and which communicates from the oil filler port 5 with the support portion.

The adapter main body 1 is fixed to a fixing block 30 attached to a fixing part 41 of a machine tool main body 40.
The fixed block 30 has a tapered support pin 3 on the front side.
1 is provided protrudingly, and a set screw 32 is attached to the lower part thereof, and the tapered fitting hole 6 is tightly fitted to the support pin 31, and the set screw 32 is inserted into the locking groove 7.
The adapter main body 1 is firmly and reliably fixed to the fixing block 30 by tightening the adapter body 1 in the engaged state.

The ultrasonic sensor 33 is attached to the fixed block 30. Note that this ultrasonic sensor 33 is
It may also be attached to the adapter main body 1 as shown by imaginary lines in FIG.

FIG. 1 shows the usage state of the tool adapter having the above-mentioned structure.
7, 28, and 29, the oil is fed between the support portion of the rotary cylindrical body 8, that is, the hole surface 11, and the outer peripheral surface of the rotary cylindrical body 8, and a thin oil film 37 is formed on this portion. The thickness of this oil film 37 is designed to be approximately uniform in the range of approximately 0.2 mm to 0.4 mm.

Subsequently, the main shaft 42 rotates to rotate the rotary tool 16 via the holder 18 and the rotary cylindrical body 8, thereby performing cutting. Then, while working, the rotary tool 1
When an overload is applied to the torque limiter 17, the torque limiter 17 is activated, and ultrasonic vibrations are generated by its engagement and disengagement operation. Ultrasonic vibrations are also generated when the rotary tool 16 breaks, comes into contact with another object, or is seriously damaged. These ultrasonic vibrations are transmitted from the rotating cylindrical body 8 through the oil film 37 to the adapter body 1 with almost no attenuation, and are detected by the ultrasonic sensor 33. At this time, since the contact area between the holder 18 and the rotating cylindrical body 8 is very small via the sphere 23, harmful ultrasonic vibrations generated on the machine tool body 40 side and transmitted to the rotating cylindrical body 8 are prevented. There is no possibility that the ultrasonic vibration will be significantly attenuated and affect the ultrasonic vibration that is effective as the detection signal described above. Therefore, the ultrasonic vibration as a detection signal generated in the rotating rotary tool 16 or the torque limiter 17 of the tool holder 13 interlocked therewith is reliably transmitted to the ultrasonic sensor 33. Then, an abnormal state of the rotary tool 16 is detected by the ultrasonic vibration detected by the ultrasonic sensor 33, and this detection signal is used to perform an appropriate tool protection operation.

Note that when the ultrasonic sensor 33 is attached to the adapter body 1, as shown by the imaginary line in FIG. 2, the influence of harmful ultrasonic vibrations from the machine body 40 side is reduced. However, in this case, it is necessary to attach the ultrasonic sensor 33 to each tool adapter, so in terms of cost and handling,
It is advantageous to attach it to a fixed block 30 as shown in FIG. At this time, the machine body 40
In order to eliminate ultrasonic vibrations transmitted from the sides as much as possible, it is desirable to make the contact area between the two as small as possible or to use an absorber.

Further, in the above embodiment, the oil supply port 5 provided in the adapter body 1 can also be used as the taper fitting hole 6. In this case, the oil supply port 5 is eliminated or sealed, and a passage 34 communicating from the tapered fitting hole 6 to the passage 25 is formed as shown by the broken line in FIG. 35 to the passage 25 via the passage 36 and passage 34.
All you have to do is supply pressure oil to the

In the above embodiment, the ultrasonic vibrations generated in the rotating member are transmitted to the adapter body through the oil film, but instead of oil, water or other liquid is supplied to the support part of the rotating cylindrical body to form a liquid film. The adapter body may be configured so that ultrasonic vibrations are transmitted to the adapter body through the liquid film.

Furthermore, between the adapter body 1 and the holder 18,
By providing a removable detent and positioning means that maintains a constant phase relationship, the tool adapter can be automatically replaced by an automatic tool changer.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a longitudinal sectional front view showing a tool adapter according to the present invention in use, and FIG. 2 is a right side view thereof. 1... Adapter body, 5... Fuel filler port, 8... Rotating cylindrical body, 13... Tool holder, 16... Rotating tool, 17... Torque limiter, 18... Holder,
19...Gripping part, 25, 26, 27, 28, 29
...Oil supply passage, 30...Fixing block, 31...
...Tapered support pin, 32... Set screw, 33...
...Ultrasonic sensor, 40...Machine body, 41...Fixed part of machine body, 42...Main shaft, 43...Drive key.

Claims (1)

[Scope of Claims] 1. An adapter body having an adapter body provided with a liquid supply port, and a rotary cylindrical body holding a rotary tool that is rotatably supported through the adapter body, and the adapter body has the above-mentioned A liquid supply passage communicating from a liquid supply port to a supporting portion of the rotary cylindrical body is provided, and an ultrasonic sensor is attached near a fixing portion of the adapter body or a machine body that fixes the adapter body. The adapter main body is fixed to a fixed part of the machine main body, and supplies liquid from the liquid supply port through the liquid supply passage to form a thin liquid film on the supporting part, and is used to attach the rotary tool or a tool holder linked thereto, etc. A tool adapter configured such that ultrasonic vibrations generated in a rotating member are transmitted from the rotating cylindrical body to the adapter body through the liquid film. 2. The tool adapter according to claim 1, wherein the liquid supplied to the supporting portion of the rotating cylindrical body via the liquid supply passage is oil or water. 3. Claim 1 or 3, wherein the adapter body is fixed by fitting into a tapered support pin of a fixing block attached to a fixing part of the machine body, and an ultrasonic sensor is attached to the fixing block. Tool adapter described in item 2. 4. A patent claim characterized in that a holder having a tapered shank portion and a gripping portion is fitted into the rear end protrusion of the rotary cylindrical body, and is detachably connected to the main shaft of the machine tool body via the holder. The tool adapter according to any one of the ranges 1 to 3. 5. The tool adapter according to claim 4, further comprising rotation preventing and positioning means for engaging and holding the holder and the adapter body in a constant phase relationship.