JP3607374B2 - Drilling bit with ultrasonic sensor and edge wear amount detection device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an excavation bit capable of detecting wear and a cutting edge wear detection device, and more particularly, can measure the cutting edge wear amount of an excavation tip in real time and with high accuracy.
[0002]
[Prior art]
Conventionally, detection of cutting edge wear in a drilling bit is, for example, a method disclosed in Japanese Utility Model Publication No. 2-36734 in which an insulation state of an insulated wire embedded in a bit body is confirmed, and a sealed space in a bit body A method disclosed in Japanese Patent Application Laid-Open No. 59-210187, in which a specific gas is sealed in and a change in electric resistance due to gas reduction due to wear is detected, provided in the loading hole up to the wear limit point of the bit body There are a method disclosed in Japanese Utility Model Laid-Open No. 62-190787, a detection method using ultrasonic waves, and the like which detect a change in the current value of the conducting wire.
[0003]
[Problems to be solved by the invention]
However, detection methods other than ultrasonic waves have poor sensing accuracy and thus lack reliability, and have problems in terms of safety and handling.
[0004]
In addition, because the conventional ultrasonic detection method could not irradiate the maximum amount of wear due to restrictions on equipment dimensions, and was replaced by a commercially available plate thickness meter using longitudinal ultrasonic waves, There are problems such as misreading due to the appearance of unnecessary ecology due to longitudinal-transverse wave conversion on the reflecting surface, and being limited to the one whose frequency is easily attenuated as the temperature rises. Furthermore, from the viewpoint of precision measurement, there was also a problem that almost no effect was given.
[0005]
For this reason, in the present invention, a refraction mode conversion method using ultrasonic waves is adopted, and improvement is made so that the transverse wave ultrasonic waves can be directly irradiated onto the worn portion of the blade edge.
[0006]
[Means for Solving the Problems]
The present invention has been made in view of the above points, and the excavation bit with an ultrasonic sensor capable of detecting the amount of wear has a transverse wave ultrasonic probe via a wedge-shaped member contacting the other end of the excavation tip. This transverse wave ultrasonic probe is provided so that the incident transverse wave ultrasonic wave is reflected from the tip of the blade edge. In this case, the wedge-shaped member is preferably made of a heat resistant resin having a refractive function. Further, the blade edge wear detection device is configured to include a measuring instrument for accurately measuring the ultrasonic echo returned from the blade edge portion of the transverse wave ultrasonic probe. In this case, the ultrasonic wave is a transverse ultrasonic wave, and the frequency is preferably 0.5 to 10 MHz, and more preferably 1 to 5 MHz.
[0007]
[Action]
In the excavation bit and the cutting edge wear amount detecting device with an ultrasonic sensor according to the present invention, the excavation tip is irradiated with a transverse wave ultrasonic wave from an ultrasonic probe via a wedge-shaped member having a refractive function. Is. Therefore, the irradiated ultrasonic wave is reflected from the cutting edge portion of the excavation tip and returned, and this feedback echo is accurately measured by a measuring instrument connected to the outside. As a result, a change in the amount of wear at the cutting edge can be detected in real time and with high accuracy. This is because there is no incident angle of the longitudinal wave in the bit body because the incident angle is greater than the critical angle of refraction of the longitudinal wave, and therefore the longitudinal wave-transverse wave mode conversion at the time of reflection at the wear parts of the drilling tip is not possible. It cannot happen and there is no fear of misreading.
[0008]
【Example】
Hereinafter, an embodiment of a drilling bit with an ultrasonic sensor and a cutting edge wear detection device of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 is a cross-sectional view conceptually showing an excavation bit with an ultrasonic sensor capable of detecting edge wear, and a bit main body 2 of a bar-shaped excavation bit 1 is attached to a cutter face plate 3 of an excavator (not shown). It can be attached by bolts (not shown). And in the notch step part 4 provided in the end of the excavation bit 1, the excavation tip 5 which consists of a cemented carbide is brazed, and the amount of wear of the edge of this excavation tip 5 is measured in real time by reflection of a transverse wave ultrasonic wave. Is done.
[0010]
Further, the excavation bit 1 has a transverse wave ultrasonic probe 6 and a wedge-shaped member 7 having an ultrasonic refraction function incorporated in the other end side of the cutting edge portion of the excavation tip 5. In summary, a receiving hole 8 is provided on the back side of the bottom surface of the notch step portion 4, and the wedge-shaped member 7 and the transverse ultrasonic probe 6 are provided on the side of the excavation tip 5 of the receiving hole 8. It is supposed to be located. In this case, the wedge-shaped member 7 has a heat resistance of .about.300.degree. The wedge angle must be variously changed depending on the shape of the excavation tip 5. At that time, the incident angle is calculated from Snell's law based on the sound speed of the excavation tip 5 and the sound speed of the wedge-shaped member 7.
[0011]
The transverse wave ultrasonic probe 6 is above the mounting pin 9 and contacts the excavation tip 5 via the wedge-shaped member 7. The mounting pin 9 is fixed by screwing the outer peripheral screw portion 11 into the screw hole portion 10 below the receiving hole 8.
[0012]
Note that a heat-resistant contact medium such as a glycerin-based viscous fluid or honey is preferably interposed between the excavation tip 5 and the wedge-shaped member 7 in order to facilitate the propagation of the transverse ultrasonic waves. In addition, the transverse wave ultrasonic probe 6 preferably has a quadrangular shape with a shape corresponding to the shape of the wedge-shaped member 7 in consideration of the directivity of the ultrasonic wave with respect to the wedge-shaped member 7.
[0013]
Accordingly, the transverse wave ultrasonic probe 6 incorporated in the excavation bit 1 irradiates the cutting edge portion of the excavation tip 5 with transverse wave ultrasonic waves of 0.5 to 10 MHz, preferably 1 to 5 MHz. This is because the eco-peak expands when the frequency is lower than 0.5 MHz, and the measurement accuracy is lowered. When the frequency is higher than 10 MHz, the attenuation increases and the eco-peak may be lost. It is. Therefore, the ultrasonic wave irradiated from the transverse wave ultrasonic probe 6 is refracted by the presence of the wedge-shaped member 7 and irradiated to the blade edge part as indicated by an arrow, and is reflected from the blade edge part and returned. To do. In this case, the cable 12 provided in the transverse wave ultrasonic probe 6 is led into the cable hole 13 and arranged outside the excavator via the connector 14 for the returned eco. Connected to the measuring instrument 15.
[0014]
Therefore, the cutting edge wear detecting device for a drill bit according to the present invention is constituted by the transverse wave ultrasonic probe 6 provided with the measuring instrument 13 and a heat-resistant wedge-shaped member 7 serving as a sensing sensor. . As a result, the measuring device 15 measures the arrival time of the echo from transmission to reception as the cutting edge wear amount of the excavation tip 5.
[0015]
In order to clarify the correlation between the bit wear amount and the eco-time, Fig. 2 shows the distance (mm) to the tip of the blade on the vertical axis and the time width of the pulse eco-interval on the horizontal axis. It is a thing. As a result, when the wear amount is about 14 mm from the wear amount O, the time width is shortened and can be detected as the wear amount.
[0016]
FIG. 3 conceptually shows another embodiment of the excavation bit 1, and the bit body 2 is provided with two excavation tips 5 and has a double-headed form. Along with this, two sets of the transverse ultrasonic probe 6 and the wedge-shaped member 7 are arranged in the bit body 2.
[0017]
【The invention's effect】
In the present invention, as described above, the excavation bit 1 with an ultrasonic sensor has the wedge-shaped member 7 and the transverse wave ultrasonic probe 6 incorporated in the bit body 2 so as to contact the excavation tip 5. It is comprised as follows. Therefore, since the ultrasonic wave is directly applied to the blade wear part, the wear amount can be detected with high accuracy.
[0018]
Further, the cutting edge wear detecting device of the excavation bit can accurately measure the time from the transmission to the reception of the ultrasonic wave by the measuring instrument 15 arranged outside. Therefore, there is an advantage that the wear amount of the cutting edge of the excavation bit 1 can be measured in real time by the precise time measurement of the ultrasonic echo.
[Brief description of the drawings]
FIG. 1 is a conceptual view showing an embodiment of an excavation bit with an ultrasonic sensor and a cutting edge wear amount detection device according to the present invention;
FIG. 2 is an explanatory diagram showing the relationship of eco-time to cutting edge wear;
FIG. 3 is a conceptual diagram showing another embodiment of the excavation bit with an ultrasonic sensor according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Drilling bit 2 Bit main body 5 Drilling tip 6 Ultrasonic probe 7 Wedge-shaped member 12 Cable 15 Measuring instrument

Claims (4)

An excavation bit capable of detecting wear of a cutting edge of an excavation tip 5 provided in the bit body 2 using an ultrasonic sensor, wherein the ultrasonic sensor includes a transverse wave ultrasonic probe. 6, and this transverse wave ultrasonic probe 6 is provided with a wedge-shaped member 7 made of a refractive function material through a contact medium on the other end side of the cutting edge portion of the excavation tip 5. An excavation bit with an ultrasonic sensor, which is incorporated in the main body 2 and is provided with a cable 12 for connecting to an external measuring instrument 15. The wedge-shaped member according to claim 1 is an excavation bit with an ultrasonic sensor according to claim 1, which is made of a heat-resistant resin. A cutting edge wear detecting device for a drill bit comprising a transverse wave ultrasonic probe 6 incorporated in a bit body and a measuring instrument 15 connected to a cable 12 provided in the transverse wave ultrasonic probe 6. ,
In the transverse wave ultrasonic probe 6, the irradiated transverse wave ultrasonic wave is reflected from the tip of the excavation tip through the wedge-shaped member 7 having a refractive function that comes into contact with the cutting edge portion of the excavation tip 5 on the other end side. The incident angle is set so that
The measuring instrument 15 is connected to the ultrasonic probe 6 via the cable 12 and the connector 14 and precisely measures the echo interval reflected and returned from the tip of the excavation tip 5 to measure the cutting edge. An apparatus for detecting the wear amount of a cutting edge of an excavation bit with an ultrasonic sensor, wherein the wear amount is detected as a wear amount. The ultrasonic wave described in claim 3 is a transverse ultrasonic wave, and the frequency is 0.5 to 10 MHz, preferably 1 to 5 MHz.

Images