JPH0450095A - Detecting method for allowable time for scuba diving - Google Patents

Abstract

PURPOSE:To have an exact knowledge of allowable time for a diver to dive by sensing air pressure in a cylinder, calculating reduction of pressure per a unit time to calculate the time for the pressure to reach a specified pressure, and indicating the time as the allowable time for diving. CONSTITUTION:In a scuba, a primary pressure reducing device 2 mounted to a cylinder 1 is connected to a secondary pressure reducing device 4 having a mouthpiece 3 by an intermediate pressure hose 5. A pressure sensor 6 is then housed on high-pressure side in the primary pressure reducing device 2, and its output signals are adapted to be connected to an electric computing device 9 in a casing 8. Air pressure P1 in the cylinder is measured, air pressure P2 in the cylinder is measured after a unit time has elapsed, a reduction rate of air pressure P/T is calculated from the measured values using P=P1-P2 and T, and based on the reduction rate of air pressure, an allowable time To for diving is determined to be indicated on a time indicator 10. Whether To reaches the time Ta assigned to floating or not is judged, and if it is judged to be 'YES', a warning is provided from an alarm 11.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a scuba device that allows free movement underwater by breathing by reducing the pressure of high-pressure air in a cylinder.
The present invention relates to a method for electronically detecting the remaining amount of air in a cylinder, that is, the available diving time.

[Prior Art] A self-contained air device that allows divers to move freely underwater is widely known as a scuba device, and is generally a cylinder filled with high-pressure air with a primary pressure reducer attached, and a hose extending from this. It has a configuration in which a secondary pressure reducer is connected to the tip of the mouthpiece, and the diver breathes by holding the mouthpiece that is integrated with the secondary pressure reducer.

In other words, since we survive underwater by carrying a cylinder and consuming the air inside, it is extremely important for safety to accurately know the remaining amount of air, that is, the possible diving time. This is confirmed by reading the pressure gauge (residual pressure needle) connected to the high pressure side of the primary pressure reducer, and in addition to this, a depth gauge and a clock are prepared and the remaining diving time is estimated based on this information. However, sufficient experience is required to make appropriate estimates with safety in mind.

In addition, the amount of air consumed varies not only between individuals, but also considerably depending on the depth of the water and the athlete, so after estimating the possible diving time, it is possible to consume more air than expected, resulting in insufficient remaining capacity in a short period of time, which could lead to an accident. There is.

[Problems to be Solved by the Invention] The problems to be solved by the present invention are that, with the information means provided by current scuba equipment, even females cannot accurately know the appropriate diving time, and therefore it is difficult to ascent. It is difficult to know the timing properly, and it is dangerous not only for beginners but also for experts.

Therefore, the present invention electronically performs an operation to calculate the possible diving time from the drop in air pressure in the cylinder and displays it, and also issues a warning of ascent, thereby accurately determining the possible diving time and the timing of ascent regardless of the amount of air consumed. The purpose of this invention is to provide a method for detecting the scuba diver's available diving time.

[Means for Solving the Problems] In order to solve the above problems, the present invention first detects the air pressure in the cylinder with a pressure sensor, and uses an electronic calculator to calculate the unit time based on the signal from the pressure sensor. We took measures to calculate the pressure drop per hit, determine the time until the set pressure is reached, and display this time as the possible diving time.

Second, in addition to the first method, a warning for ascent is issued when the remaining diving time reaches a predetermined time.

Any pressure sensor can be selected from known types such as an aneroid type, capacitance type, and semiconductor piezoresistive type, and it may be built into the cylinder, but it is easier to handle if it is built into the high pressure side of the primary pressure reducer. It is advantageous.

It is also convenient to integrate the electronic calculator, time display, and alarm, and to hang it from the diver's chest or abdomen via a signal line that sends the electrical signal generated by the pressure sensor to the electronic calculator. . The electronic arithmetic unit is a well-known microcomputer equipped with input/output circuits, memory circuits, arithmetic circuits, etc., and the time display is a liquid crystal type that digitally displays the remaining diving time and is visually readable. This is convenient, and it is also effective to have an alarm that emits a sound like a buzzer.

The cylinder starts to be used at an average filling pressure of about 150 kg/am, and the next pressure reducer lowers the water pressure by 8 to 10 kg/cm.
It is well known that breathing is performed by reducing the pressure to a higher pressure, and then reducing the pressure to about the same level as water pressure using a secondary pressure reducer. Since the amount of air consumed per unit time varies not only between individuals and the amount of exercise, but also depending on the depth of the water, there is considerable variation in the rate at which the air pressure in the cylinder decreases.

In the present invention, the air pressure in the cylinder is continuously sensed by a pressure sensor, and the signal is continuously input to an electronic calculator, so that the pressure P at time T1 and the pressure P2 at time T2, a time ΔT after this, are obtained. The pressure difference Δ by sampling
Find P=P+-P2. - It is necessary for safety that air remains in the cylinder with a sufficient margin when floating, and the pressure P3 is set to achieve this.

Assuming that the pressure decreases at the rate of △P, we know the time T3 at which the set pressure P3 is reached, so the possible diving time TO from time T2 is △P/△T= (P2-P3)
/ (T3-T2)T3-T2=T.

From this, it is determined by T o = (P 2 - P 3) △T/△P. In reality, since momentum and water depth change, sampling is repeated at appropriate time intervals to obtain ΔP, and To is sequentially corrected. TO is displayed on a time display, and in that case, if the sampling time interval is short, a constant value may be displayed during that time, but generally it is linked to a timer to count down, and a new U)To is displayed each time sampling is performed. It is preferable to repeat the switching and display the TO in real time.

Next, set time T4 with sufficient margin before T3 so that the floating period ends before the set pressure P3 is reached, and the time ΔTa given by T3-T4=ΔTa is the possible diving time. When assigned from TO and reaches T4, a warning for ascent will be issued. This warning may be issued only once, but it is preferable to issue it intermittently or continuously until the ascent is completed to alert the diver.For this purpose, it is linked with the depth gauge to warn the diver when the water depth reaches zero. It is better to stop the

[When diving in exactly the same way as before with the Coscuba equipped,
Visually check the time indicator to confirm the available diving time. Additionally, a warning is issued when the remaining time reaches a predetermined time. As a result, it is possible to appropriately notify the remaining diving time and the timing of ascent.

[Example] FIG. 1 is a diagram schematically showing an example of a scuba to which the present invention is applied, in which a primary pressure reducer 2 attached to a cylinder 1 is connected to a secondary pressure reducer 4 having a mouthpiece 3 and a medium pressure It is connected by a hose 5 and is also connected to a buoyancy regulator and a preliminary secondary pressure reducer (not shown).

A pressure sensor 6 is installed built-in on the high pressure side of the primary pressure reducer 2,
This pressure sensor 6 is connected to an electronic calculator 9 housed in a casing 8 through a waterproof signal line 7.

A time indicator 10, an alarm 11, and a water depth gauge 12 are incorporated into the casing 8.

Next, an example of the operation of detecting and displaying the available diving time and issuing a warning using such a configuration will be described with reference to the flowchart of FIG. 2.

First, the air pressure P1 in the cylinder is measured in block 21, the time is counted in block 22, and when the unit time ΔT has elapsed, the air pressure P2 in the cylinder is measured in block 23.
Next, in block 24, the rate of decrease in air pressure ΔP/ΔT is calculated using ΔP=P l-P 2 and ΔT, and based on this, the available diving time To is determined in block 25 and displayed on the time display. . Furthermore, in block 26, it is determined whether the time △Ta allotted to TO for ascent has been reached, and if it has not, the process returns to block 21 and the above operation is repeated, and if so, the process proceeds to block 27 to ascent. If it is determined in blocks 28 and 29 that ΔTa is zero and the water depth is zero, the operation is completed; otherwise, the process returns to block 27 and continues issuing a warning.

[Effects of the Invention] According to the present invention, the available diving time is electronically calculated and displayed based on the drop in air pressure in the cylinder, and a warning for ascent is issued. It allows for proper notification and is extremely safe.

[Brief explanation of drawings]

FIG. 1 is a schematic layout diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart of the operation. 1...Cylinder, 2...-order pressure reducer, 6...Pressure sensor, 7...Signal line, 9...Electronic calculator, 10...Time display, 11...Alarm, 2nd floor ,-ji

Claims (1)

[Claims] 1. The air pressure in the cylinder is detected by a pressure sensor, and based on the signal from the pressure sensor, an electronic calculator calculates the pressure drop per unit time, and the time required to reach the set pressure. A method for detecting available diving time for scuba, characterized by determining the available diving time and displaying this time as available diving time. 2. In addition to the method according to claim 1, a scuba diving time detecting method further comprising the step of issuing an ascent warning when the remaining diving time reaches a predetermined time.