JPH0235930B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a testing device for testing the durability of a valve body, etc. under specific temperature conditions.

[Prior Art] The durability of diaphragms and valve bodies made of elastic materials such as rubber largely depends on the temperature conditions of equipment to which they are applied. For this reason, the test is conducted in a constant temperature room that can reproduce the intended temperature environment. That is, as shown in FIG. 1, the valve body 1 to be tested is attached to a valve body support housing 2 and placed in a constant temperature room 3, and pressurized gas is supplied to the valve body support housing 2 through a switching valve 4. By alternately connecting the supply circuit 5 and the pressure reduction circuit 6, different pressures P ₁ and P ₂ (P ₁ > P ₂ ) are applied to the test valve body 1 to test its durability. .

[Problems to be Solved by the Invention] However, when testing the durability of a valve body used in an automobile carburetor, etc. under extremely cold conditions of, for example, -40°C, the pressurized gas applied is at atmospheric temperature. Therefore, due to the dew point temperature, dew condensation and ice formation occur in the piping 7 in the thermostatic chamber 3 or in the valve body support housing 2, making it impossible to properly apply a predetermined pressure fluctuation to the test valve body 1. It was hot. In order to deal with such drawbacks, conventional test equipment is equipped with a condensation box 8 in the piping 7 in the thermostatic chamber 3, but since its capacity is limited, the condensation box 8 cannot be used during long-term tests. Eventually, however, a layer of ice builds up, reducing the intended effect and requiring time and effort to remove it. On the other hand, regarding the applied pressures P ₁ and P ₂ , for a valve body that operates under negative pressure, such as the above-mentioned valve body for a carburetor, theoretically P ₁ is atmospheric pressure (0 kg
f/cm ² ), P ₂ is negative pressure. However, −40
In order to create extremely cold conditions such as ℃, it is necessary to cool the gas using a dehumidifier or the like. Generally, in order to efficiently dehumidify and cool using a dehumidifier, for example,
It is required to supply gas pressurized to 1.5 to 9 Kgf/cm ² to the dehumidifier. For this reason, a pressure regulating valve (pressure reducing valve) is provided in the pressurized gas circuit 5 to reduce the pressure of the pressurized gas for cooling to near atmospheric pressure, and supply the reduced pressure gas to the pipe 7. However, the pressure P ₁ could only be reduced to about 0.05 Kgf/cm ² using the pressure regulating valve alone, and in this sense, there was a drawback in the durability data under negative pressure conditions.

This invention was made in view of the above-mentioned drawbacks of the conventional apparatus, and its purpose is to prevent moisture in the applied pressurized gas from condensing or freezing even when the test temperature condition of the thermostatic chamber is set to 0°C or lower. It also makes it possible to quickly reduce the pressure of this pressurized gas to almost atmospheric pressure without causing any risk of damage, and allows a predetermined pressure fluctuation to be appropriately applied to the test valve body, making it suitable for use in vaporizers, etc. The object of the present invention is to provide a test device suitable for testing the durability of negative pressure operated valve bodies, etc.

[Means for Solving the Problems] The present invention provides a constant temperature chamber in which the test temperature can be set to a specific temperature below zero degrees Celsius, and a support housing that supports a test object such as a valve body made of an elastic material in the constant temperature chamber. and a pressure control device including a pressurized gas supply circuit and a pressure reduction circuit provided outside the constant temperature chamber;
and a switching valve that selectively connects each circuit to the support housing, and by operating the switching valve in a predetermined cycle, different pressures are applied to the test piece to test the durability of the test piece under specific temperature conditions. In the equipment to be tested, the pressurized gas supply circuit and the switching valve are connected in series in order to dehumidify the pressurized gas in the pressurized gas supply circuit to a dew point temperature below the specified test temperature of the constant temperature room. A dehumidifying means constituted by a combination of a refrigerating dehumidifier and a water vapor adsorption dehumidifier, a pressure regulating valve for reducing the pressure of the pressurized gas dehumidified by this dehumidifying means, and a pressure regulating valve that reduces the pressure of the pressurized gas by this pressure regulating valve. It is characterized in that it is connected to a pressure storage means for storing pressurized gas, and the pressure storage means is provided with a pressure relief valve device made of soft rubber that further reduces the pressure of the reduced pressure gas to approximately atmospheric pressure. It is something.

[Function] The pressurized gas is first cooled primarily by the refrigeration dehumidifier of the cooling means, and then secondarily cooled by the water vapor adsorption dehumidifier connected in series to the refrigeration dehumidifier. Therefore, for example, in a refrigerated dehumidifier -15
By cooling the pressurized gas to ℃ and then further cooling it with a water vapor adsorption dehumidifier, it is possible to easily create a gas with a temperature as cold as -40℃, and it is sufficiently dried to prevent condensation. , gas that does not freeze can be sent to a constant temperature room. The pressurized gas thus cooled is then reduced in pressure to some extent by the pressure regulating valve, and the reduced pressure gas is stored in the pressure storage means. Since the pressure storage means includes a pressure relief valve device, the pressure of the pressurized gas can be reduced to approximately atmospheric pressure by adjusting the relief valve device. The pressure relief valve device makes the valve opening pressure depend on the elasticity of the rubber, and is made of soft rubber so that the valve opening pressure can be set low, allowing accurate pressure regulation even in low temperature gases.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that in FIG. 2, parts corresponding to those in FIG. 1 are given the same reference numerals.

As stated in the explanation related to Fig. 1, this test device is equipped with a constant temperature chamber 3 that can set the test temperature to a specific temperature below 0°C, and has a test valve made of an elastic material such as rubber. The body 1 is placed in a constant temperature room 3 while being attached to a valve body support housing 2. On the other hand, a pressurized gas supply circuit 5 and a pressure reduction circuit 6 as pressure control devices are provided outside the thermostatic chamber 3, and these circuits 5 and 6 are equipped with a known switching valve 4 and The valve body support housing 2 is alternately connected to the valve body support housing 2 via a connecting pipe 7. The pressurized gas supply circuit 5 includes a dehumidifying means 9
The pressurized gas supplied from the circuit 5 is dehumidified in advance by the dehumidifying means 9 so that its dew point temperature is lower than the test temperature in the thermostatic chamber 3.
Dehumidifiers can be roughly divided into refrigeration type, which forcibly cools the air temperature and condenses condensate, and vapor adsorption type, which uses adsorbent to adsorb moisture in the air. In the invention, the dehumidifying means 9
It is preferable that the dehumidifier consists of a combination of a refrigerating dehumidifier 10 and a water vapor adsorption dehumidifier 11 connected in series at the subsequent stage, thereby creating an almost complete dehumidifying state (dew point temperature -40°C or less). can. Note that reference number 12 is a drain separator of the cooling type dehumidifier 10. Suitable examples include the IDF2B-041 type refrigeration dehumidifier manufactured by Sintered Metal Industry Co., Ltd. and the ID type water vapor adsorption dehumidifier manufactured by the same company. The pressurized gas (P ₁ = 7Kgf/cm ² ) in the circuit 5 is
First, the refrigerating dehumidifier 10 performs primary dehumidification to a dew point of about -15°C, and then the water vapor adsorption dehumidifier 11 performs secondary dehumidification to a dew point of around -40°C. In this way, the almost completely dehumidified pressurized gas is approximately 0.05 kg by the known pressure regulating valve (pressure reducing valve) 13.
The pressure is reduced to f/cm ² . In this case, the pressurized gas is further reduced in pressure by the pressure storage chamber 14 having the pressure relief valve 15 to a pressure value approximately equal to atmospheric pressure. That is, as shown in FIGS. 3 to 5, the pressure relief valve device 15 includes a plurality of umbrella-shaped check valves 18 attached to the outside of the bottom plate 17 so as to cover the exhaust hole 16 thereof. ing. In this case, the umbrella-type check valve 18 is made of extremely flexible rubber material,
Preferably, the umbrella-shaped seal portion 19 is a small one having a diameter of 20 mm and a thickness of 0.5 mm, and responds sensitively to even weak pressure. Thereby, the pressurized gas from the circuit 5 is reduced in pressure in this pressure storage chamber 14 to a pressure of P ₃ of about 0.001 Kgf/cm ² . In addition, the umbrella type check valve 18
has an umbrella-shaped fitting part 20 with a diameter of about 2 mm directly on its back surface, and the bottom plate 17 of the pressure relief valve device 15 is connected to the bottom plate 17 of the pressure relief valve device 15 through a bulging head 21 formed at the tip thereof.
It has become firmly fixed.

As is clear from the description of the embodiments described above, according to the present invention, the pressurized gas in the pressurized gas supply circuit 5 is almost completely dehumidified by the dehumidifying means 9, and then the pressurized gas is dehumidified by the known pressure regulating valve 13. The pressure is reduced to about 0.05Kgf/cm ² at the pressure storage chamber 14, and then the soft rubber umbrella-type check valve 18 of the pressure relief valve device 15 in the pressure storage chamber 14 reduces the pressure to 0.001Kgf/cm 2 , which can be considered almost equal to atmospheric pressure.
The pressure is reduced to a pressure of P ₃ on the order of cm ² . Therefore, by operating the switching valve 4 in a predetermined cycle, the pressure P ₃ and the negative pressure P ₂ from the pressure reducing circuit 6 communicating with a pressure reducing means (not shown) act alternately on the valve body 1 to be tested. In this case, even under severe cold test conditions around -40°C, there is no condensation in the connecting pipe 7 in the thermostatic chamber 3 or in the valve body support housing 2.
A predetermined pressure fluctuation can be appropriately applied to the test valve body 1 without forming ice. Also, pressure
Since P ₃ is reduced to a level that can be considered almost equivalent to atmospheric pressure, when testing valve bodies used in carburetors, etc., the durability is tested under conditions that are closer to actual negative pressure operation. This makes it possible to obtain highly reliable data.

In addition, by providing heat exchange means 22 such as radiation fins in the connecting pipe 7 in the thermostatic chamber 3 to cool the inflow gas applied to the test valve body 1, the actual severe cold conditions can be reproduced as much as possible. Can be done.

[Effects of the Invention] As described above, the durability testing device for valve bodies, etc. of the present invention dehumidifies the pressurized gas in the pressurized gas supply circuit to a dew point temperature below the specific test temperature of the thermostatic chamber. Because it has a refrigeration dehumidifier and a water vapor adsorption dehumidifier connected in series, it is possible to perform primary cooling with the refrigeration dehumidifier and then secondary cooling with the water vapor adsorption dehumidifier, making it easy to achieve the desired extreme cold. In addition to being able to lower the gas temperature to a certain temperature, it is also possible to send sufficiently dry gas that does not form dew or ice to the thermostatic chamber. In addition, the gas that has been brought to high pressure for dehumidification is once reduced in pressure by a pressure regulating valve and then stored in a pressure storage means equipped with a pressure relief valve device, making the valve opening pressure dependent on the elasticity of the rubber. By adjusting the pressure relief valve device made of soft rubber or the like so that the valve opening pressure can be set low, the pressure can be reduced to approximately atmospheric pressure.

[Brief explanation of drawings]

Figure 1 is a schematic system diagram showing a conventional example;
The figure is a schematic system diagram showing the test device according to the present invention, Figure 3 is a perspective view of the pressure relief valve device, and Figure 4 is a perspective view of the pressure relief valve device.
The figure is a longitudinal sectional view of the umbrella check valve, and FIG. 5 is a longitudinal sectional view showing its operating state. In the drawings, 1 is a test valve body, 2 is a support housing, 3 is a constant temperature room, 4 is a switching valve, 5 is a pressurized gas supply circuit, 6 is a pressure reduction circuit, 7 is a connecting pipe, 9 is a dehumidifying means, and 10 is a refrigeration unit. 11 is a water vapor adsorption dehumidifier, 13 is a pressure regulating valve, 14 is a pressure storage chamber, 15
1 is a pressure relief valve device, and 18 is an umbrella check valve.

Claims (1)

[Scope of Claims] 1. A constant temperature chamber in which the test temperature can be set to a specific temperature below zero degrees Celsius, a support housing that supports a test object such as a valve body made of an elastic material within the constant temperature chamber, and an outside of the constant temperature chamber. a pressure control device including a pressurized gas supply circuit and a pressure reduction circuit, and a switching valve that selectively connects each circuit to the support housing, and by operating the switching valve in a predetermined cycle. , an apparatus for testing the durability of the test object under specific temperature conditions by applying different pressures to the test object, wherein the pressurized gas is connected between the pressurized gas supply circuit and the switching valve. Dehumidification means configured by a combination of a refrigeration dehumidifier and a water vapor adsorption dehumidifier connected in series to dehumidify the pressurized gas in the gas supply circuit to a dew point temperature below the specified test temperature of the thermostatic chamber. , a pressure regulating valve for reducing the pressure of the pressurized gas dehumidified by the dehumidifying means, and a pressure storage means for storing the pressurized gas reduced by the pressure regulating valve, and the pressure storage means is connected to the pressure regulating valve for reducing the pressure of the pressurized gas dehumidified by the dehumidifying means. A durability testing device for a valve body, etc., characterized in that a pressure relief valve device made of soft rubber is provided to further reduce the pressure of the pressurized gas to approximately atmospheric pressure. 2. An apparatus for testing the durability of valve bodies, etc. according to claim 1, wherein the pressure relief valve device is constituted by an umbrella-type check valve made of soft rubber.