JPH0119100B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to wooden poles commonly called "utility poles" for supporting power transmission and distribution or communication lines, or trees (these are collectively referred to as "wooden poles" in this specification).
This invention relates to a test device for determining the decay of wood.

Traditionally, the methods used to determine the rot of a wooden pole include directly visualizing the damage after excavation at the base, and determining the sound produced by hitting the wooden pole with a hammer. There were problems with the former, such as internal decay being difficult to detect, and the latter requiring considerable skill. In addition, there are other methods, such as the perforation measurement method based on the length of growth and the sonic transmission method, but these methods are low in accuracy and have many practical problems.

Therefore, recently, a drill-type wooden column rot tester has been proposed.

The purpose of the present invention is to improve this drill-type wooden pole rot tester, and by focusing on the fact that wooden poles have annual rings, it is possible to detect the disappearance of annual rings in decaying parts. Therefore, it is an object of the present invention to provide a wooden pole rot tester that can reliably detect rot.

An embodiment of the present invention will be described below with reference to the drawings. In Fig. 1, reference numeral 1 is a drill, and the shaft part except the tip part is tapered to prevent friction between the side wall of the hole drilled by the drill 1 and the shaft part of the drill 1. This is done so as not to adversely affect the measurements described below. This drill 1 is rotationally driven by a rotary drive mechanism 2, and is sent out at a constant speed by a delivery mechanism 3,
The tip is made to penetrate inside the wooden pillar while making a hole in it. Although the rotary drive mechanism 2 and the delivery mechanism 3 are shown as separate blocks in the figure for ease of understanding, they can actually be constructed integrally using one small motor as the drive source. This sending mechanism 3 is provided with a detector 4 for detecting thrust force, and a detection signal obtained from the detector 4 is sent to a circuit section 5. Power is supplied to the rotational drive mechanism 2, the sending mechanism 3, the detector 4, and the circuit section 5 from a battery 6.

As shown in FIG. 2, the circuit section 5 includes an amplifier circuit 51 that amplifies the detection signal, a differentiation circuit 52 that differentiates the amplified signal, and a comparator that detects whether the differential output is greater than a reference level. 53, and a circuit 54 for detecting the period of the output of the comparator 53.
and a display or recording circuit 55.

Next, the operation of the wooden pole rot tester having the above structure will be explained with reference to FIG. 3A, B, C, and D represent signal waveforms at each point a, b, c, and d in FIG. 2. Drill 1
As the drill drills into the inside of the wooden pillar at a constant speed, the inside of the wooden pillar has annual rings, that is, relatively hard parts and relatively soft parts overlap in layers. The reaction force (thrust force) that occurs changes in accordance with the growth of the tree rings. As a result, the detection signal obtained from the thrust force detector 4 and amplified by the amplifier circuit 51 repeats high and low levels according to the annual rings, as shown in FIG. The annual rings have disappeared and there is almost no difference between the hard and soft parts, resulting in a relatively uniform soft part, resulting in a constant signal level. So the standard level
It is also possible to set L ₁ and determine it as a rotten part when it falls below this value, but since the signal level may be high as shown in FIG. 3A, the present invention detects a rotten part more reliably. In order to do this, the system detects when the signal pattern corresponding to the tree rings disappears. Therefore _{, the} output signal of the amplifier circuit 51 is differentiated with respect to time to obtain a differential output as shown in _{FIG .} The pulse wave shown in Fig. 3C is obtained (Fig. 3C is a case in which it is detected that L ₂ is exceeded), and its period T _i , T _{i +1} , T _i+2 . . . are detected by the period detection circuit 54. That is, either the maximum value of the period is determined in advance and it is detected that the period T _i becomes larger than this value, or the period ratio T _{i +1} /T _i is set.
It is detected that the measured value has become larger than the set value of T _i+1 /T _i . In this way, when the signal pattern corresponding to the tree rings disappears, a decayed part detection signal d as shown in FIG. 3D is output and displayed or recorded.

Since the drill 1 penetrates into the interior of the wooden column at a constant speed, the depth from the surface of the decayed part can be determined by the timing at which the signal d is generated, and this depth can also be displayed or recorded at the same time.

As described above in the embodiments, according to the present invention, the wooden pole has annual rings (repetition of hard and soft parts).
Since this phenomenon disappears in a decayed part, a decayed part is determined when the pattern of the thrust force detection signal disappears according to the annual ring. Therefore, the accuracy of determination is improved. Additionally, since the drill penetrates into the interior of the wooden column at a constant speed, the location (depth from the surface) of the rotten area can be easily determined. Furthermore, since the drill can be rotated and sent out using a single small motor, and a battery can be used as a power source, it is possible to realize a wooden pole rot tester that is small, lightweight, and easy to carry as a whole.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
The figure shows a detailed block diagram of the circuit section 5 in FIG.
Figures A, B, C, and D are signal waveform diagrams at points a, b, c, and d in Figure 2. DESCRIPTION OF SYMBOLS 1... Drill, 2... Rotation drive mechanism, 3... Sending mechanism, 4... Thrust force detector, 5... Circuit part, 6... Battery.

Claims (1)

[Claims] 1. A drill, a rotational drive mechanism for this drill, a delivery mechanism that sends out the drill at a constant speed, a detector that detects the thrust force of the drill, a differentiation circuit that differentiates a detection signal from this detector, and A waveform shaping circuit that shapes the output signal of a differentiating circuit to obtain a pulse wave, and a cycle that detects the cycle of the pulse wave signal of this waveform shaping circuit and generates a rotten part detection signal in response to an increase in the cycle. A wooden pole decay tester consisting of a detection circuit.