JPH0646175B2 - Internal pressure creep test equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an internal pressure creep test apparatus, and more particularly to a test apparatus capable of easily applying a predetermined pressure to a heating furnace without legal problems.

(Prior art and its problem) The internal pressure creep test device, a high pressure is applied to the internal space of the cylindrical test piece in a state of being maintained at a predetermined temperature,
The characteristics of the test piece are investigated by examining the time until the test piece breaks. Therefore, the internal pressure creep test device is generally a pressurizing device that applies pressure to the internal space of the test piece, a pressure adjustment and control device that measures the magnitude of pressure and adjusts it to an appropriate value, a heating furnace and heating to heat the test piece. It includes a temperature measurement and adjustment device that measures the temperature of the furnace and adjusts it to an appropriate value.

One of the conventionally used internal pressure creep test devices is one in which the pressure medium is water and the pressure control system is the accumulator heating system. This is to adjust the magnitude of the pressure applied to the test piece by putting the pressure accumulating tank in the hot water tank and adjusting the temperature of the hot water. At that time, the initial pressure setting is to pressurize with a high pressure pump, measure with a pressure converter or a precision pressure gauge, and close the high pressure valve. The pressure decrease due to the expansion of the cylindrical test piece is always kept constant by heating the pressure accumulator tank and expanding the water therein.

However, since the pressure accumulator is heated, it is subject to legal restrictions, and a special manufacturing technique is required especially for the design of a pressure vessel in which the pressure exceeds 1000 kg / cm ² .
Also, on the user side who installs the test device, the initial cost and the running cost are increased due to the legal regulation for safety management of the pressure accumulator. Further, when the design pressure of the pressure accumulator is 1000 to 1500 kg / cm ² , the thickness of the body of the pressure vessel becomes thicker accordingly, and if pressure control is performed by temperature control, control is delayed in time. Occurs, and as a result, the pressure control accuracy deteriorates.

As another internal pressure cleaving test device, there is a device in which water is used as a pressure medium and the pressure control is a gas buffer (accumulator) system. This is to solve the deficiency of the above-mentioned accumulator heating method, in which water is not used as the pressure medium, but a gas (gas) which is a compressible fluid is used, and the rise and fall of the pressure is buffered to some extent by the gas. Then, it is intended to maintain a constant pressure. When the water pressure decreases, the valve is opened to replenish the high-pressure gas, and when the water pressure increases, the valve is opened to maintain a constant pressure.

However, the pressure of the compressed gas may exceed 10 kg / cm ² , and in such a case, it is necessary to be regulated by law. In addition to that, the user must make a prescribed notification or application. Especially the pressure is 1000kg
The test equipment that exceeds / cm ² must be given special permission by the manufacturer and the user, which limits the manufacturing and installation. Also, the pressure is 1000 kg / cm
^Since the use of the compressed gas of ² is very dangerous, the installation place of the test apparatus is limited, and the initial cost and running cost increase due to the need to ensure safety.

The present invention solves the above problem, that is, it is not necessary to prepare a pressure vessel having high pressure resistance in the case where the pressure control system is a pressure accumulator heating system, and a high pressure gas such as a gas buffer system is used. It is an object of the present invention to provide a test device capable of performing an internal pressure creep test of a test piece extremely safely without being subject to the regulation of law, without danger of using.

(Means and Actions for Solving the Problem) In order to solve the means for solving the above problems, in the present invention, water is used as a pressure medium and a pressure control device having a specific structure is used. And More specifically, the test apparatus is a water tank storing water, a heating furnace connected to the water tank and having a heater for heating the test piece housed in the hollow portion, and a water tank on the water pipe in the vicinity of the water tank. A water pump arranged and a pressure control device arranged between the water pump and the heating furnace were included in the water pipeline. The pressure control device includes a first portion that is in communication with the water conduit and has a small cross-sectional area, and a second portion that has a small cross-sectional area that contains compressed gas and has a much larger cross-sectional area than the first portion. , A piston member extending over the first and second portions.

Since the cross-sectional area of the first portion is much smaller than the cross-sectional area of the second portion (for example, about 1/180), it is only necessary to supply the compressed gas having a relatively low pressure to the second portion. An extremely high pressure can be obtained in the part.

(Example) Hereinafter, the Example of this invention is described based on drawing.

In the internal pressure cleaving test apparatus shown in FIG.
A compressed air driven water pressure pump 14, a compressed air driven automatic valve 16, an overflow prevention valve 18, etc. are arranged on the water tube furnace 12 that supplies the water in 0 to the test piece 52 in the electric heating furnace 50. It is set up. Compressed air is supplied to the water pressure pump 14 from an air compressor (air compressor) 20, and the compressed air from the air compressor 20 is also supplied to a water pressure control device 30 via a low pressure gas control device 28 including electromagnetic valves 24 and 26 described later. To be supplied to. Water pressure controller 3
0 is connected between the automatic valve 16 and the overflow prevention valve 18 of the water pipe 12.

Next, each component will be described in detail.

The water level in the water tank 10 is detected by the level switch 32, and an alarm is issued when the water level falls below a predetermined level. A filter 36 is attached near the outlet of the water tank 10 so as to remove dust in the water.

The water pressure pump 14 supplies water to the test piece 52 in the heating furnace 50 and is driven by compressed air of about 7 kg / cm ² supplied from the air compressor 20 to generate about 150
A water pressure of 0 kg / cm ² is generated. The air compressor 20 is driven by a motor 38, and the maximum air pressure is about 9.5 kg / cm ² . A pressure reducing valve 38 is provided in a pipe line from the air compressor 20 to the water pressure pump 14 to reduce the maximum air pressure of 9.5 kg / cm ² and supply the pressure to the water pressure pump 14.

Further, an upper limit type pressure gauge 40 is provided on the downstream side of the water pressure pump 14 (close to the heating furnace 50), and an electromagnetic valve 42 provided close to the water pressure pump 14 at the pressure upper limit is closed to prevent the water pressure pump 14 from overpressure. Prevent it from joining. The air-driven automatic valve 16 operates with compressed air supplied from the air compressor 20, decompressed (6 kg / cm ² ) and introduced from the three-way valve 44.

As shown in FIG. 2, the water pressure control device 30 includes the water pipe 12
And a cylindrical large diameter portion 64 integrated with the cylindrical small diameter portion 62, and a piston member 66 interposed between both portions. Small diameter part 62 and large diameter part 6
The cross-sectional area ratio with respect to No. 4 is about 1: 180, and the inner space of the small diameter portion 62 is filled with water in the water pipeline 12, and the inner space of the large diameter portion 64 is filled with compressed air.

An upper limit pressure gauge 54 is provided near the water pressure control device 30, and the solenoid valves 24 and 26 are provided. The operation of the solenoid valves 24 and 26 is controlled by a pressure indicating regulator 70 described later. An upper limit pressure gauge 72 is provided at a portion where the small diameter portion 62 of the water pressure control device 30 intersects with the water pipe line 12, and the overflow prevention valve 18 is provided on the downstream side thereof. This overflow prevention valve 18
When the test piece 52 breaks, further water is prevented from being fed.

An upper and lower limit type pressure gauge 74 and a pressure converter 76 are provided near the overflow prevention valve 18. The pressure gauge 74 issues an alarm at the upper limit of the pressure and detects that the test piece 52 is broken at the lower limit of the pressure. The pressure transducer 76 is
The test pressure is detected, and the pressure applied to the test piece 52 is controlled and its magnitude is recorded. The pressure instruction adjuster 70 measures and controls the pressure of the pressure converter 76, and opens the low pressure side solenoid valve 24 at the upper pressure limit and closes the high pressure side solenoid valve 26 at the lower pressure limit. To maintain a constant test pressure.

The heating furnace 50 has a cylindrical shape, and a cylindrical test piece 52 can be accommodated in the hollow portion thereof. Further, a heater 54 for heating the test piece 52 is built in around the hollow portion. The internal space of the test piece 52 is sealed, and the water in the water tank 10 is supplied to this.

In the heating furnace 50, the hollow portion of the test piece 52 has 15
The internal pressure creep rupture test is performed by measuring the time until the test piece 52 is broken by applying a water pressure of about 00 kg / cm ² and heat from the heater 53.

In addition, in this embodiment, three heating furnaces (four in total) other than those shown in the drawing are provided, and the water supply circuit and the compressed gas supply circuit are also configured correspondingly ( See No. 2, No. 3 and No. 4).

(Operation) According to the present embodiment, the large diameter portion 64 is 8 kg / cm ²
Only a small amount of compressed air is supplied to the small-diameter portion 62.
A high pressure of about 00 kg / cm ² can be obtained. This is because the pressure control device 30 in which the cross-sectional area ratio between the small diameter portion 62 and the large diameter portion 64 is a high ratio of about 1: 180 is adopted. To set the above-mentioned pressure, the water pipe 12 and the small diameter portion 62 of the pressure control device 30 are filled with water by the hydraulic pump 14, and then compressed air is gradually supplied to the large diameter portion 64 to increase the pressure. The pressure converter 74 detects whether or not a predetermined pressure is obtained. When the predetermined pressure is obtained, the solenoid valve 24 on the low pressure side is closed.

On the contrary, when the water pressure exceeds a predetermined value, the solenoid valve 24 may be opened to supply the compressed gas. When the test piece 52 has a large expansion amount and the amount of water supplied by the hydraulic pump 14 is insufficient, the automatic valve 16 on the high-pressure side is opened to supply water, and the water pressure is correspondingly increased. It is improved and a predetermined pressure can be obtained.

The position of the piston member 66 of the water pressure control device 30 can be visually confirmed, or can be electrically confirmed by providing a pair of limit switches 82 and 84.

(Effect of the Invention) As described above, according to the present invention, in the internal pressure creep test, the low pressure compressed gas is used to control the high water pressure applied to the test piece. As a result, it is not necessary to prepare a special control device that can withstand high pressure for pressure control, and it is not subject to the application of pressure vessels under the Ministry of International Trade and Industry High Pressure Gas Control Act and the Ministry of Labor Safety and Health Act. Since no physical procedure is required and pressure control is simple, anyone can operate it without requiring special technology.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing the main part (pressure control device) thereof. [Explanation of Signs of Main Parts] 10 ... Water Tank 12 ... Water Pipeline 14 ... Water Pump 20 ... Air Compressor 30 ... Pressure Control Device 50 ... Heating Furnace

Claims (2)

[Claims] 1. An internal pressure creep test apparatus in which a test piece heated in a heating furnace is connected to a water tank via a pipe line and an internal pressure is applied to the test piece by a hydraulic pump provided in the pipe line. A piston member having a first portion connected to the second portion and a second portion having a cross-sectional area larger than that of the first portion, and an internal pressure of the test piece is applied to the first portion to form a second portion. Is provided with a pressure control device configured to apply a pressure lower than that of the first portion by a compressible gas, and controls the internal pressure by moving the piston member when the internal pressure of the test piece fluctuates. Internal pressure creep test device configured. 2. When the fluctuation of the internal pressure of the test piece exceeds a predetermined range, the gas pipeline for supplying a compressible gas from a supply source is opened / closed so that the compressed gas applied to the second portion of the piston member is The internal pressure creep test apparatus according to claim 1, wherein the internal pressure is controlled by adjusting the pressure.