JPH08303911A - Refrigerant charging device - Google Patents

Abstract

PURPOSE: To provide a refrigerant charging device of which the device is simplified and miniaturized, and which is inexpensive. CONSTITUTION: When a liquefying/pressurizing unit 19 operates, a liquid piston 8a slides in the longitudinal direction. In this case, an automatic valve 17 closes, and when one of the chambers of a cylinder 9 is under a refrigerant-pressurizing state, and the other chamber is placed under a refrigerant suction state. When a liquefied refrigerant is filled in the piston front chamber 9a and piston rear chamber 9b at a set liquefied pressure, the pressurization of the liquefying/pressurizing unit 19 stops, a charging/pressurizing unit 20 operates, and the liquid piston 8a retracts to the deepest end. In this case, the automatic valve 17 is opened, and the liquefied refrigerant in the piston rear chamber 9b removed to the piston front chamber 9a. Then, the automatic valve 17 is closed, charging/pressurizing unit 20 is operated, and the liquid piston 8a advances. Then, the piston front chamber 9a is pressurized, and the pressure is raised to a set charging pressure or higher, and the liquefied refrigerant is charged into equipment from the charging gun 16 by reducing the pressure to a specified pressure. The mass flow rate of a flow which is generated at this time is measured by a mass flow meter 13, and the charging weight is calculated at a charging control unit 21, and the control is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant charging device for charging a refrigerator or the like with a refrigerant.

[0002]

2. Description of the Related Art Generally, R-22 and R- are used in factories.
To fill a refrigerator with a CFC-based refrigerant such as 134a,
A refrigerant charging device is used to charge an exact specified amount (g) of refrigerant. In addition, due to the recent regulation of freon-based refrigerants and the commercialization of small-sized and highly efficient refrigerators, refrigerant is filled with higher accuracy using a refrigerant filling device.

As shown in FIG. 4, a conventional refrigerant charging device 50 includes a booster pump 51 operated by compressed air,
A cylinder 52 that stores the refrigerant to be filled, a hydraulic pump 53 that pressurizes a movable piston 52a of the cylinder 52, a pulse scale 54 that measures the position of the piston 52a, and a thermometer 55 that measures the temperature of the refrigerant to be filled.
It has an automatic valve 56 operated by compressed air, and a filling control unit 57 for controlling these, and is configured to fill a specified amount of refrigerant from a charging gun 58 into a refrigerator or the like.

That is, the refrigerant supplied to the refrigerant charging device 50 from a cylinder or the like is pressurized by the booster pump 51 to fill the inside of the device in a liquid state. At this time, the automatic valve 56 is in the open state, and the refrigerant is also stored in the cylinder 52 while maintaining the liquid state. Then, the automatic valve 56 is closed, and the hydraulic pump 5 is closed.
At 3, the piston 52a of the cylinder 52 is pressurized and moved to fill the refrigerant in the cylinder 52 into the refrigerator or the like via the charging gun 58. Here, the filling control unit 57 informs the cylinder shape information and the temperature of the refrigerant to be filled under the pressure applied by the hydraulic pump 53.
The liquid density (g / cm ³ ) characteristic is stored, the liquid density of the refrigerant is obtained from the temperature measured by the thermometer 55, and the movement amount (volume) of the piston 52a corresponding to the weight of the refrigerant to be filled is stored.
Is converted and set, and the piston 5 is
While monitoring the position of 2a, the piston 52
By moving a, the specified amount of the refrigerant that has been set is accurately filled into a device such as a refrigerator.

[0005]

However, in the above-mentioned conventional refrigerant charging device, the booster pump as described above is required to keep the refrigerant in the refrigerant path of the device in the liquid state, and the device becomes complicated and large in size. There is a problem that it becomes expensive.

In addition, the temperature of the liquid refrigerant is measured to obtain the liquid density, and the moving amount of the piston corresponding to the refrigerant filling amount (the weight of the refrigerant to be filled) is converted and set to fill the refrigerant. Therefore, many precision parts such as an accurate thermometer, an accurate cylinder, a pulse scale that can accurately detect the amount of piston movement of the cylinder, and a hydraulic pump unit that stops the piston accurately are required. There is a problem that the device becomes complicated and large and expensive, the environment in which the device is used is limited, and regular adjustment and maintenance are required.

Further, it is necessary to store accurate physical property data (temperature-liquid density data) of the refrigerant in the charging control section, and if many kinds of refrigerants are to be charged, a huge amount of data will be stored. Must be stored in advance.

Further, when a gas refrigerant is generated in the apparatus for some reason, it is difficult to detect it, and when such an abnormality occurs, there is a possibility that an incorrect amount of refrigerant is filled. is there.

Further, since the refrigerant weight is filled (indirect filling) calculated, the actual filling weight must always be checked.

The present invention has been made in view of the above circumstances, and the booster pump required in the conventional apparatus is also used as the pressurizing means at the time of filling, so that the apparatus can be simplified and downsized, and an inexpensive refrigerant can be obtained. The primary purpose is to provide a filling device, and further, the device is simplified and downsized, is inexpensive, has a wide range of environmental conditions in which it can be used, and requires minimal adjustment and maintenance. It is possible to perform quantitative filling of various types of refrigerant without storing the data in advance, and it is also possible to easily detect the generation of gas refrigerant in the device, and to measure the actual filling weight accurately. A second object of the present invention is to provide a refrigerant charging device that can be used.

[0011]

In order to achieve the above object, a refrigerant charging device according to claim 1 of the present invention keeps a refrigerant in a liquid state in a path, and charges the liquefied refrigerant into a device through an injection part. In a refrigerant charging device, a cylinder in which two chambers of variable volume are partitioned and formed by a piston that is slidable forward and backward, and a liquefaction process that slides the piston to suck the refrigerant and pressurize it at a set liquefaction pressure to maintain a liquid state It is provided with a pressure means and a charging / pressurizing means for sliding the piston to pressurize the refrigerant at a set charging pressure for charging.

Further, in the refrigerant charging device according to the second aspect of the invention, in the refrigerant charging device which keeps the refrigerant as a liquid in the path and charges the liquefied refrigerant into the device through the injection part, the piston is slidable back and forth. A cylinder in which two chambers of variable volume are partitioned and formed, a piston is slid to suck the refrigerant, and a liquefaction pressurizing unit that pressurizes at a set liquefaction pressure to maintain a liquid state, and a piston is slid to remove the refrigerant. A charging / pressurizing means for pressurizing and charging at a set charging pressure, a mass flow rate measuring means for measuring the mass flow rate of the liquefied refrigerant flowing between the cylinder and the injection part, and controlling the liquefying / pressurizing means. On the other hand, a filling control means for controlling the filling pressurizing means based on the mass flow rate measured by the mass flow rate measuring means is provided.

[0013]

In the refrigerant charging device according to the first aspect of the present invention, in order to suck and pressurize the refrigerant to keep it in the liquid state, the liquefying and pressurizing means slides the piston of the cylinder divided into two chambers. Then, the refrigerant is sucked through one of the cylinder chambers and pressurized at the set liquefied pressure through the other cylinder chamber to be kept in the liquid state. When the suction of the refrigerant by the liquefaction pressurizing means is completed and the refrigerant in the path including the two chambers of the cylinder is in the liquid state of the set liquefied pressure, the charging pressurizing means slides the piston. The refrigerant is pressurized at the set charging pressure, and the liquefied refrigerant is charged into the device via the injection part.

Further, in the refrigerant charging device according to the second aspect, in order to suck and pressurize the refrigerant to keep it in the liquid state, the liquefaction pressurizing means is controlled by the charging control means and divided into two chambers. Slide the piston of the cylinder. Then, the refrigerant is sucked through one of the cylinder chambers and pressurized at the set liquefied pressure through the other cylinder chamber to be kept in the liquid state. When the suction of the refrigerant by the liquefaction pressurizing means is completed and the refrigerant in the path including the two chambers of the cylinder is in the liquid state of the set liquefying pressure, the filling pressurizing means is controlled by the filling control means, The piston is slid to pressurize the refrigerant at the set charging pressure, and the liquefied refrigerant is charged into the device via the injection part. The filling weight of the refrigerant to be filled in the equipment is calculated by the filling control means based on a signal from the mass flow rate measuring means for measuring the mass flow rate of the liquefied refrigerant flowing between the cylinder and the injection part. The filling / pressurizing means is controlled based on the weight.

[0015]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 3 show an embodiment of the present invention, FIG. 1 is an explanatory diagram of a refrigerant charging device, FIG. 2 is an explanatory diagram of a structure of a piston of a cylinder, and FIG. 3 is an explanatory diagram of a mass flowmeter.

In FIG. 1, reference numeral 1 indicates a refrigerant charging device, and a refrigerant inlet 2 of the refrigerant charging device 1 is provided with R-22, R-22.
A cylinder 3 of a fluorocarbon refrigerant such as R-134a is connected.

The refrigerant inlet 2 is provided with a first check valve 6 via a valve 4 and a filter 5, and a second check valve provided in parallel with the first check valve 6 on the refrigerant path. The first check valve 6 communicates with the valve 7, and the downstream side of the first check valve 6 is connected to a piston front chamber 9a of a cylinder 9 which is divided into two chambers by a liquid piston 8a of a piston 8 and the second check valve 6a. The downstream side of the check valve 7 is connected to the piston rear chamber 9b of the cylinder 9.

Further, the piston front chamber 9a is connected to a third check valve 10, and the piston rear chamber 9b is connected to a fourth check valve 11, which is connected to the third check valve 10. On the downstream side of the fourth check valve 11, a filter 12, a mass flow meter 13 as a mass flow rate measuring device, a one-way valve 14,
It is connected via a valve 15 to a charging gun 16 as an injection part for the liquefied refrigerant. Further, a path from the piston front chamber 9a to the third check valve 10 and a path from the piston rear chamber 9b to the fourth check valve 11 are bypassed, and this bypass path is used. Is an automatic valve 1
7 are provided.

As shown in FIG. 2, the piston 8 has a liquid piston 8a fixed to the front end of a rod 8c, which is slidable in the cylinder 9 in the front-rear direction.
An air piston 8b which is slidable in the air cylinder 18 in the front-rear direction is fixedly provided at the rear end portion of c. A shaft 8d projecting from the piston front chamber 9a is slidably provided in the rod 8c, and the shaft 8d is biased in a projecting direction by a spring 8e. That is, in the shaft 8d, the cross-sectional area of the piston front chamber 9a and the cross-sectional area of the piston rear chamber 9b are substantially the same, in other words, the piston front chamber 9a generated by the movement of the liquid piston 8a. And the volume change of the piston rear chamber 9b are substantially the same.

The air cylinder 18 is connected to a liquefaction pressurizing section 19 as a liquefaction pressurizing means and a filling pressurizing section 20 as a filling pressurizing means.
Is pressurized by using compressed air or the like, and the air piston 8 is
slide b in the air cylinder 18 in the front-back direction,
The liquid piston 8a is slidable in the cylinder 9 in the front-rear direction. Here, the inside of the cylinder 9 is pressurized by the liquefaction pressurizing unit 19 to a pressure of about 20 kg / cm ² .

Similarly, the filling and pressurizing unit 20 is also pressurized by using compressed air or the like to slide the air piston 8b in the air cylinder 18 in the front-rear direction, and the liquid piston 8a is moved to the cylinder 9 in the same manner. It is designed to slide in the front-back direction. Here, the inside of the cylinder 9 is pressurized by the filling / pressurizing unit 20 to a pressure of about 25 kg / cm ² .

The charging gun 16 is formed so that the equipment-side outlet opens when the pressure applied to the inlet side valve seat becomes about 25 kg / cm ² or more. The refrigerant is charged into the device by the pressure generated by.

The mass flowmeter 13 is a mass flowmeter having a high responsiveness to changes in the flow rate so that the mass flow rate of the liquefied refrigerant having a high pressure can be accurately measured, and has a wide measurement range, for example, as shown in FIG. As shown in (a), two flow tubes 25, 25 adjusted to have the same natural frequency (inertia) and fixed at both ends, an electromagnetic oscillator 26 for vibrating the flow tube 25, and a flow tube 25.
The angle detection unit 27 mainly detects the twist angle θ of the flow tube 25 generated by the flow of the fluid inside.

That is, in the mass flowmeter 13, as shown in FIG.
As shown in (b), the flow tube 25, whose both ends are fixed, resonates at a natural frequency by the electromagnetic oscillator 26, and when the fluid flows in the flow tube 25, the fluid flows in opposite directions to the inflow side and the outflow side. The force (Coriolis force) is applied, and the flow tube 25 moves as shown in FIG. 3C during the half cycle of vibration, and as shown in FIG.
Twisted as in (d). This twist angle θ is proportional to the mass flow rate in the flow tube 25, and is detected by the angle detection units 27 mounted on both sides as a signal proportional to the mass flow rate, and the mass flow rate is obtained. The mass flowmeter 13 is composed of two flow tubes adjusted to have the same natural frequency (inertia), and detects the positional relationship between the two flow tubes. Even so, the forces exerted on the two pipes act to cancel each other out, and the effect is extremely small. Further, in this mass flow meter 13, when gas is generated inside the pipeline, an abnormality is shown in the value of the mass flow rate, so that it is easily determined that gas is generated inside the pipeline.

The mass flow meter 13, the one-way valve 14, the automatic valve 17, the liquefaction pressurizing unit 19 and the filling pressurizing unit 20 are connected to a filling control unit 21 as a filling control means.

The filling control unit 21 is formed so that the weight of the refrigerant to be filled in advance can be set, and the mass flowmeter 1 is also provided.
Based on the signal indicating the mass flow rate input from 3, the integrated value of the mass flow rate is calculated to find the filling weight, and the mass flow rate and the filling weight are displayed on a display unit (not shown). And the operations of the one-way valve 14, the automatic valve 17, the liquefaction pressurizing unit 19 and the filling pressurizing unit 20 are controlled. Further, the filling control unit 21 is pre-filled so that the purpose of the research and development / specification (refrigerant amount) determination of the refrigerator and the additional refrigerant amount inspection by abnormality detection in the inspection of the refrigerator production line can be performed. Do not set the weight of the refrigerant to
The refrigerant can be filled while monitoring the filling weight.

In FIG. 1, reference numerals 31 and 32 indicate pressure gauges for measuring the respective pressures of the respective pipelines, and reference numeral 33 indicates a safety valve.

Next, in the refrigerant charging device having the above-mentioned structure, a specified amount of refrigerant (for example, R-22, R-13) is supplied to a device such as a refrigerator.
The operation of filling a CFC-based refrigerant such as 4a) will be described.

First, as shown in FIG. 1, a cylinder 3 of CFC-based refrigerant is connected to the refrigerant inlet 2, and the liquefied refrigerant in the cylinder 3 is filled in the refrigerant passage in the apparatus 1 with the charging gun. 16 is connected to a device, and the filling control unit 21
When the weight of the refrigerant to be charged is set in advance and the device 1 is operated, the liquefaction pressurizing unit 19 is operated by the filling control unit 21, the air piston 8b of the air cylinder 18 is slid back and forth, and the liquid piston of the cylinder 9 is moved. 8a is slid back and forth. At this time, the automatic valve 17 is operated by the filling control unit 21.
When the one chamber of the cylinder 9 is in the refrigerant pressurization state, the other chamber is in the refrigerant suction state. For example, in the process in which the liquid piston 8a moves forward and pressurizes the piston front chamber 9a, the refrigerant is sucked from the cylinder 3 by the piston rear chamber 9b, and then the piston front chamber 9a has a pressure of about 20 kg / cm ^2. When the liquid piston 8a is retracted by being pressurized to the above pressure, the piston rear chamber 9b is pressurized. In this process, the refrigerant is sucked from the cylinder 3 into the piston front chamber 9a. By repeating this, the piston front chamber 9a and the piston rear chamber 9b are
When the liquefied refrigerant is filled therewith and the pressure is increased to about 20 kg / cm ² , the pressure applied by the liquefaction pressurizing unit 19 is stopped.

Next, the filling control unit 21 operates the filling pressurizing unit 20, retracts the air piston 8b, and retracts the liquid piston 8a to the end. At this time, the filling control unit 21 keeps the automatic valve 17 open. Therefore, the liquefied refrigerant in the piston rear chamber 9b is moved to the piston front chamber 9a. Here, since the shaft 8d is adjusted so that the volume change of the piston front chamber 9a caused by the movement of the liquid piston 8a and the volume change of the piston rear chamber 9b become substantially the same, the refrigerant is gasified. There is nothing to do.

Next, the filling control section 21 closes the automatic valve 17, operates the filling pressurizing section 20, advances the air piston 8b, advances the liquid piston 8a, and advances the piston front. The chamber 9a is pressurized.

When the pressure reaches about 25 kg / cm ² or more, the liquefied refrigerant is charged from the charging gun 16 into the equipment at a predetermined pressure. The mass flow rate of the flow of the refrigerant generated at this time is measured by the mass flow meter 13, and the signal from the mass flow meter 13 is sent to the filling control unit 21 to be converted into the mass flow rate value and the mass flow rate value. Is added to calculate the filling weight, and these values are displayed. When the filled weight reaches the set weight, the filling control unit 21 stops the filling pressurizing unit 20, closes the one-way valve 14, and finishes the filling of the refrigerant. When the refrigerant is filled, the piston rear chamber 9b is replenished with the refrigerant from the cylinder 3 as the liquid piston 8a moves. In addition, at the time of filling, the mass flowmeter 13
When an abnormal mass flow rate value is input from, it is displayed and
The filling amount until the abnormality occurs is displayed and filling is stopped.

Then, to fill the other equipment, again,
The refrigerant is sucked from the cylinder 3 and the operation is performed as described above. An example of this operation is an example in which the filling weight is set in the filling control unit in advance and the filling is performed. However, the filling weight may be monitored while the filling weight is monitored without setting the filling weight in the filling control unit. It is possible.

As described above, according to this embodiment, the booster pump required in the conventional device is also used as the pressurizing means at the time of filling, so that the device can be simplified and downsized. .

Further, since the mass flow rate is measured and the filling weight is directly obtained, the actual filling weight check work, which is required in the conventional apparatus, is unnecessary.

Further, since the mass flow rate is measured and the filling weight is directly obtained, if a gas refrigerant is generated in the apparatus for some reason, it should be detected from the value of the mass flow rate. Can be done easily.

Further, since the mass flow rate is measured, it is not necessary to store accurate physical property data (temperature-liquid density data) of the refrigerant in the device in advance, and it is possible to fill many kinds of refrigerant. .

Further, since the filling weight is not calculated and obtained from indirect various parameters but directly measured, many precision parts and electronic parts for calculation which are required in the conventional apparatus are omitted. Can simplify the equipment,
The size and cost can be reduced, and the environmental conditions that can be used are wide, and adjustment and maintenance can be easily performed.

In this embodiment, R-22, which serves as the refrigerant, is used.
Although the apparatus using the chlorofluorocarbon refrigerant such as R-134a has been described, the invention is not limited to this.

The pressure applied by the liquefaction pressurizing unit and the pressurization by the filling pressurizing unit are about 20 kg / cm ² and about 25 kg / cm ² , respectively, due to the physical properties of R-22 and R-134a. Although the pressure is applied, the present invention is not limited to this, and when a substance other than R-22 and R-134a is targeted, the above pressure values are changed according to the physical properties of the target substance. Needless to say.

In this embodiment, the mass flowmeter is
The method using the Coriolis force generated by the fluid flowing in the resonated flow tube has been illustrated, but the method is not limited to this and the flow rate must be set so that the mass flow rate of the liquefied refrigerant at high pressure can be accurately measured. A mass flowmeter that has high response to changes and has a wide measurement range may be used.

[0042]

As described above, according to the invention of claim 1, the booster pump required in the conventional device is also used as the pressurizing means at the time of filling, so that the device can be simplified and downsized. An inexpensive device can be realized.

Further, according to the invention of claim 2, the booster pump required in the conventional device is also used as the pressurizing means at the time of filling, so that the device is simplified and downsized, and the inexpensive device is realized. In addition to the effect of making it easier, the device is simple and compact, it is cheap, the environmental conditions that it can be used are wide, only minimal adjustment and maintenance are required, and a huge amount of data is stored in advance. It is possible to perform quantitative filling of various types of refrigerants without using it, and moreover, it is possible to easily detect the generation of gas refrigerant in the device, and it is possible to accurately measure the actual filling weight.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a refrigerant charging device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a structure of a piston of a cylinder according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a mass flowmeter according to an embodiment of the present invention.

FIG. 4 is an explanatory view of a conventional refrigerant charging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerant charging device 3 Cylinder 8a Liquid piston 9 Cylinder 9a Piston front chamber 9b Piston rear chamber 13 Mass flow meter 16 Charging gun 19 Liquefaction pressurizing part 20 Filling pressurizing part 21 Filling control part

Claims (2)

[Claims] 1. A refrigerant filling device for keeping a refrigerant as a liquid in a path and filling the liquefied refrigerant into a device through an injection part, wherein a cylinder in which two chambers having variable volumes are defined by a piston slidable forward and backward. Liquefaction pressurizing means for sliding the piston to suck the refrigerant and pressurizing it at a set liquefying pressure to maintain a liquid state, and sliding the piston to pressurize the refrigerant at a set charging pressure to perform filling. A refrigerant charging device comprising a pressurizing means. 2. A cylinder in which two chambers of variable volume are defined by a piston slidable forward and backward in a refrigerant filling device for keeping a refrigerant as a liquid in a path and filling the liquefied refrigerant into a device through an injection part. Liquefaction pressurizing means for sliding the piston to suck the refrigerant and pressurizing it at a set liquefying pressure to maintain a liquid state, and sliding the piston to pressurize the refrigerant at a set charging pressure to perform filling. A pressurizing means, a mass flow rate measuring means for measuring the mass flow rate of the liquefied refrigerant flowing between the cylinder and the injection part, and controlling the liquefying pressurizing means, while measuring with the mass flow rate measuring means. A refrigerant filling device, comprising: a filling control unit that controls the filling pressurizing unit based on a mass flow rate.