JPH06198548A - Durability evaluation method for boring drill for elastic foam body and durability evaluation device - Google Patents

Abstract

PURPOSE:To prevent a fracture of a drill and to reuse it after grinding by detecting a displacement amount of an elastic foam body by a displacement sensor when it is perforated by a boring drill and determining the durable time limit when the displacement amount reaches the fixed value. CONSTITUTION:Under the condition that a spot of a laser type displacement sensor 31 is matched to a measurement position M around the upper part of a boring drill insertion position, and under this condition, a zero signal is sent to a meter relay 33 from a sequencer 34. Then, a boring operation of a polyurethane foam body 10 by a drill 20 is started and displacement, of the foam body 10 in the measurement position M during the boring operation is detected continuously by the laser type displacement sensor 31 and its output signal is converted by a sensor amplifier 32 into a voltage signal to be outputted to the meter relay 33. When the detected voltage signal value is above the predetermined upper limit value of the displacement, an H signal is outputted, and an alarm buzzer 35a is rung when the H signals are outputted several times, for example three times, continuously, and then an automatic boring cycle is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for evaluating the durability of a perforated drill of elastic foam.

[0002]

2. Description of the Related Art A perforated drill of elastic foam of this type has different durability depending on its quality. Further, this hole drill has an advantage that it can be used again and again by polishing when it becomes poor in sharpness, but its durability also differs depending on the degree of polishing. And when the sharpness of the drill deteriorates by making holes in the elastic foam, the holes made in the elastic foam may become larger or smaller, and the diameter of the holes may vary, and the drill may become elastic foam. Entangled, the problem of bending or breaking the drill occurred. Moreover, when the sharpness of the drill became poor, the shape of the chips generated during drilling became a state in which the center was swollen. Then, by knowing the occurrence of these phenomena, the service life of the drill is determined, and the perforated drill is replaced.

[0003]

However, if the service life of the drill is determined as described above, many defective products are produced due to variations in hole diameter, which is very wasteful. Further, in order to deal with bending or breaking of the drill, the manufacturing equipment must be stopped for a long time, and a drill that is once bent or bent cannot be re-polished and reused, which is a waste. . In order to avoid these problems, a method in which the operator constantly monitors the drilling work can be considered, but as mentioned above, the durability of drilling drills varies greatly, so The task of properly determining is very complicated and not practical. The present invention is intended to solve the above problems, and an object thereof is to provide a method and an evaluation device for automatically and appropriately evaluating the durability of a perforated drill of an elastic foam.

[0004]

In order to achieve the above-mentioned object, the structural feature of the invention according to claim 1 is that the vicinity of the drilling position of the elastic foam is set as the measurement position,
The displacement sensor detects the displacement amount of the elastic foamed body at the same measurement position when the drill is drilled, and when the displacement amount reaches a certain value, it is determined to be the useful life of the drill.

Further, the structural feature of the invention according to claim 2 is that the displacement sensor for detecting the displacement of the elastic foam body at the measurement position near the drilling position when the elastic foam body is drilled by the drilling drill. And a service life determining means for determining that the service life of the drill is the service life when the displacement amount detected by the displacement sensor reaches a certain value.

[0006]

In the invention according to claim 1 configured as described above, the amount of displacement of the elastic foam near the drilling position of the elastic foam by the drill is increased by increasing the number of times the drill is used. Utilizing the property that
The displacement amount is detected by a displacement sensor, and when the displacement amount reaches a constant value, it is determined that the drill has a service life. That is, when a hole is made in the elastic foam by a drill, as shown in FIG. 2 (a), the steps of start, penetration, return, and completion go through, but the displacement of the displacement amount at the measurement position M in the vicinity of the drilling position. The measurement result by the sensor is as shown in FIG. Figure 2
The value of H shown in (b) is taken as the amount of displacement, and when the amount of displacement reaches a certain value, it is judged as the service life of the drill. As a result, according to the invention of claim 1, it becomes possible to automatically and properly determine the service life of the drill, thereby preventing many product defects. The product yield can be improved. Further, since the drill can be reused by collecting it and polishing it again before making it unusable, the drill can be effectively used and the price can be reduced. Further, it is possible to avoid the production apparatus from being stopped for a long time due to breakage of the drill or the like.

Further, in the invention according to claim 2 configured as described above, the displacement sensor detects the displacement amount of the elastic foam at a measurement position in the vicinity of the drilling position of the elastic foam by the drill, When the displacement amount reaches a certain value, the service life expiration determining means automatically and accurately determines that the drill has the service life expiration. As a result, the effect described in claim 1 can be obtained by using the durability evaluation device for the perforated drill of elastic foam according to claim 2.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows an apparatus for measuring the durability of a polyurethane foam 10 which is an embodiment of the present invention when drilling a hole with an electric drill 20. That is, the perforated drill 2 of the polyurethane foam 10
A displacement detecting device 30 detects a displacement at a position M near an upper hole (hereinafter, referred to as a measurement position) M by 0, and the recording device 40 records the result.

The displacement detecting device 30, as shown in FIG.
A laser-type displacement sensor (hereinafter referred to as a displacement sensor) 31 that detects a displacement at a measurement position M when the polyurethane foam 10 is drilled and outputs the displacement signal, and a displacement output from the displacement sensor 31 is converted into a voltage signal. The sensor amplifier 32 that outputs the H1 signal to the sequencer 34 when the displacement signal from the sensor amplifier 32 exceeds a preset upper limit value of the displacement, and the signal from the meter relay 33. A sequencer 34 which receives the preset drill use limit condition, generates an alarm when the drill use limit condition is exceeded, and stops the automatic manufacturing cycle. The use limit conditions of the drill are as follows: (1) The H1 signal is continuously output three times from the meter relay when the polyurethane hole is opened (at this time, the alarm buzzer 35a sounds and the alarm indicator lamp 35b lights up). , (2) and (1), further, the H1 signal is continuously output three times from the meter relay (at this time, the automatic manufacturing cycle is stopped).

Next, the operation of the embodiment configured as described above will be described. First, the spot of the displacement sensor 31 is aligned with the measurement position M in the vicinity of the upper part of the hole drilling insertion position. After this alignment is completed, the sequencer 34 is operated by a command from a servo (not shown) in the automatic manufacturing cycle.
Sends a zero signal to the meter relay 33. The command from the servo is sent to the sequencer 34 every time the work of punching the polyurethane foam 10 is completed.

Next, the drilling operation of the polyurethane foam 10 by the drill 20 is started, and the displacement of the polyurethane foam 10 at the measurement position M at this time is measured by the displacement sensor 3.
1 continuously detects and outputs a detection signal to the sensor amplifier 32. The sensor amplifier 32 converts the signal indicating the displacement amount from the displacement sensor 31 into a voltage signal (H value shown in FIG. 2B) and outputs the voltage signal to the meter relay 33. The meter relay 33 outputs the H1 signal to the sequencer 34 when the voltage signal value is equal to or more than the set upper limit value of the displacement. When the H1 signal from the meter relay 33 is continuously input three times, the sequencer 34 drives the alarm buzzer 35a to generate an alarm sound and turn on the alarm indicator lamp 35b. When the H1 signal from the meter relay 33 is continuously input three more times, the sequencer 34 sends a stop signal to the servo to stop the automatic drilling cycle. Then, the drill 20 is replaced with a new or re-polished product.

FIG. 4A shows the recording result of the H value shown in FIG. 2B obtained by converting the displacement output from the displacement sensor 20 into a voltage signal in the above-described drilling process using a drill. As shown in (c), the number of drilling is about 20 times, 500 times, and 1060 times.
At 60 times, the displacement amount H is very large. Also,
From the results showing the change in the displacement amount H of the polyurethane foam 10 depending on the number of drilling times, as shown in FIG. 5, in the case of the new drill (A), when the number of drilling times exceeds 1000 times, especially 1050 times. It is clear that the degree of displacement increases. And this tendency is as shown in FIG.
It was clarified that the same was true when the drill with the number of drilling times exceeding 1060 was used after being re-polished (B). Further, although only a part is shown in FIG. 5, the result similar to that of the re-polished product B was obtained also for the re-polished product B which was re-polished.

As described above, according to the above-described embodiment, the service life of the drill for drilling can be automatically and properly determined, so that the drill can be operated without any monitoring by the operator. The production system is automatically shut down when the service life limit of the drill is known and the drill reaches the service limit. Therefore, many product defects can be prevented from occurring, and product yield can be improved. Further, since the drill can be reused by collecting it and re-polishing it before making it unusable, the drill can be effectively used. Further, it is possible to avoid the production apparatus from being stopped for a long time due to bending of the drill.

In the above embodiments, the case where polyurethane foam is used as the elastic foam has been described. However, the present invention is applied to the step of punching another elastic foam such as polyolefin foam. May be. Further, in the above-mentioned embodiment, the laser type displacement sensor is used as the displacement sensor, but the displacement may be detected by using, for example, an ultrasonic type sensor, a photoelectric conversion sensor, a magnetic sensor or the like.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an apparatus for measuring the durability of a drill in drilling a polyurethane foam with a drill according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a measurement principle of the measurement device.

FIG. 3 is a block diagram of a displacement measuring device of the same measuring device.

FIG. 4 is a chart diagram showing a recording result showing a displacement measurement waveform of the measuring apparatus.

FIG. 5 is a graph showing changes in the displacement amount of the polyurethane foam when the number of times of drilling is changed using the same measuring device, for a new drill and a re-polished drill.

[Explanation of symbols]

10; polyurethane foam, 20; perforated drill, 30;
Displacement detection device, 31; laser displacement sensor, 32; sensor amplifier, 33, meter relay, 34, sequencer, 3
5a: alarm buzzer, 35b: alarm indicator light, M: measurement position.

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[Procedure amendment]

[Submission date] January 20, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (2)

[Claims] 1. A displacement sensor detects a displacement amount of an elastic foam body at the same measurement position when a hole is drilled by the drill, and the displacement amount is detected by a displacement sensor. The method for evaluating the durability of a perforated drill made of elastic foam is characterized in that the life of the drill is judged to be a certain value. 2. A displacement sensor for detecting the displacement of the elastic foam body at a measurement position in the vicinity of the drilling position when the elastic foam body is drilled by a drill, and a displacement amount detection value by the displacement sensor becomes a constant value. A durability evaluation device for a perforated drill made of an elastic foam, which is provided with a service life determination means for determining that the service life of the perforated drill is reached.