JPS6113891Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a refrigerant filling device for air conditioners, and it automatically performs the work associated with refrigerant filling to ensure safe work and reliable filling. It is. Conventionally, in this type of refrigerant filling device, all the work associated with filling was performed by a timer switch that could set the time, but with this type of refrigerant filling device, the time was simply a uniform work. No measures were taken to deal with fluctuations in working conditions due to cooling device capacity, temperature, etc.
For this reason, the amount of refrigerant to be charged, especially during filling operations, cannot be determined solely by the filling time, as the amount of evaporation of the refrigerant varies depending on the temperature. There was a large variation in the load depending on the load, and this was very inconvenient to perform uniform work depending on the time. Furthermore, the uncertainties caused by the above-mentioned problems lead to incomplete filling, which necessitates manual work, which is dangerous when handling high-pressure refrigerant gas.

In this invention, however, the work associated with refrigerant charging can be completely automated, and the refrigerant can be reliably filled.

The embodiment will be explained below with reference to the drawings. Reference numeral 1 denotes a refrigerant device, which is composed of a refrigerant compressor 2, an evaporator 3, a condenser 4, etc. Low-pressure and high-pressure connection valves 6, 7 are provided for this purpose.
8 is a refrigerant filling device. 9 is a refrigerant can, and 10 is a valve attached to the refrigerant pipe 9, which is equipped with a check valve 11 to allow the refrigerant to flow into only one side. Reference numeral 12 denotes a can opener blade provided on the mounting valve 10 for opening the seal of the refrigerant can 9 when the refrigerant can 9 is installed. 13 is an outflow control valve that controls the outflow of refrigerant;
4 is an expansion valve, and 15 is a vaporizer for forcibly vaporizing the refrigerant, which are connected in this order to the mounting valve 10, the outflow control valve 13, the expansion valve 14, and the vaporizer 15. 1
Reference numeral 6 denotes a low-pressure refrigerant pipe line that communicates with the outlet side of the vaporizer 15, and a coupling valve 17 that is connected to a compound gauge 50 that displays the refrigerant pressure and degree of vacuum, and the low-pressure connection valve 6 of the compressor 2. has been established. 18 is a connection valve 1 connected to the high pressure connection valve 7
9 and a compound gauge 20 that displays the pressure and degree of vacuum of the refrigerant on the high-pressure side. Reference numeral 21 denotes a refrigerant detector such as a pressure switch, which is provided in the middle of the refrigerant pipe 18 and detects the filling pressure of the refrigerant. Reference numeral 22 denotes a bypass refrigerant pipe that communicates with the low-pressure refrigerant pipe 16 and the high-pressure refrigerant pipe 18, and is provided with a low-pressure on-off valve 23 and a high-pressure on-off valve 24 that appropriately communicate these pipes. , 24, a pump line 26 is drawn out to a vacuum pump 25 which evacuates the refrigerant line. 2
A communication valve 7 is provided in the pump line 26 to control the flow to the vacuum pump 25, and is operated when the vacuum pump 25 is operated to connect the line.
28 is a refrigerant discharge valve, which is a communication valve 27 of the pump pipe line 26.
The refrigerant in the refrigerant pipe is discharged into the atmosphere as necessary when the pipe 26 is opened.

Reference numeral 29 denotes a pulse generator which is connected to the rotating shaft 3 of the vacuum pump 25 in synchronization with the rotation of the refrigerant pipe 25, for example.
It consists of a magnetic body 32 attached to the magnet 1 and a magnetically sensitive element 33 that detects this magnetism, and generates a pulse signal synchronized with rotation. A pulse counter 34 counts the signal, and a gate circuit 36 outputs a signal that matches the signal from a setting circuit 35 in which the number of pulses has been set in advance, thereby controlling a switching circuit 37. At this time, the switching circuit 37 closes when the power is turned on, and opens in response to an output signal from the gate circuit 36 to stop the evacuation operation and to operate the outflow control valve 13. 38 is a power switch, 39a is a relay contact to the vacuum pump circuit of the switching circuit 37, 39b is a relay contact to the outflow control valve of the circuit 37, and 40 is the electric motor of the vacuum pump 25. Next, the operation will be explained. First, the cooling device 1 and the refrigerant charging device 8 are connected, and when the power switch 38 is closed, the normally closed relay contact 39a rotates the vacuum pump 25, and the high-pressure and low-pressure on-off valves 23, 24, Opening the communication valve 27 and evacuating all the refrigerant pipes,
The pulse signal of the pulse generator 29 due to the rotation of the vacuum pump 25 is counted by the pulse counter 34, this counted value is counted until it matches the number of pulses set in advance by the setting circuit 35, and this match is detected by the gate circuit 36. This causes the signal to be output from the switching circuit 37 to open the relay contact 39a, thereby stopping the operation of the vacuum pump 25, etc., and stopping the evacuation operation. When this is completed, the outflow control valve 13 is operated by the relay contact 39b to start charging the refrigerant into the refrigerant pipe.The refrigerant detector 21, such as a pressure switch, detects the amount of refrigerant charged, and the outflow control valve 13 is closed to start filling. This is to stop the Although this example shows the basic filling operation, a more complete filling operation can be achieved by activating the vacuum pump circuit again based on the signal from the refrigerant detector 21 that detects the end of the filling operation and repeating the operation as appropriate. can be done. In addition, the changeover switches 41, 4
For example, after stopping charging, closing the changeover switch 42 to perform refrigerant charging and forcibly rotating the compressor 2 will further increase the refrigerant charging. This can be done forcibly and the optimum filling amount can be achieved, and the evacuation operation can also be operated as desired by the changeover switch 41.

As described above, this invention is configured to generate a pulse signal from a pulse generator, which is constructed by placing a magnetic sensing element in opposition to a magnetic body that rotates with the rotation of a vacuum pump that vacuums the refrigerant pipe. The operation time of the vacuum pump is counted and the operating time of the vacuum pump is controlled. At the end of this control, the outflow control valve of the filling pipe, which supplies refrigerant to the refrigerant pipe, is opened, and the supply of refrigerant is stopped. Since it is controlled by a refrigerant detector that detects the refrigerant pressure in the pipe, the work during refrigerant filling can be done automatically, making it convenient and easy to handle. Since the vacuum in the passage is controlled by detecting a pulse signal proportional to the actual rotation amount of the vacuum pump, there is no possibility that the rotation of the electric motor and the rotation of the vacuum pump may differ due to an inconvenience in the transmission device, or the amount of work may change due to fluctuations in load. It is also possible to control according to the actual amount of work and perform a reliable vacuum, and compared to the conventional uniform control based on time, it is possible to perform a reliable vacuum and prevent air from entering the refrigerant. This prevents the compressor from breaking down by increasing the cooling effect and allowing the compressor to rotate smoothly. In addition, the refrigerant pipes are filled with refrigerant until the refrigerant detector detects the refrigerant after the evacuation is completed, so the refrigerant is always filled only at the set amount even if there are differences in charging conditions such as temperature and capacity of the cooling device. can be filled with
It is possible to perform reliable filling, and it is possible to prevent filling problems caused by insufficient evaporation of refrigerant at low temperatures, or insufficient filling amount when filling large air conditioners, which was seen with uniform filling using a conventional timer. It has the advantage of being able to eliminate imperfections and ensure reliable work, and is also excellent in safety during work because these works can be performed automatically and reliably.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of the configuration of this invention. FIG. 3 is an example of an electric circuit. FIG. 4 is an explanatory diagram of the mounting valve part. FIG. 5 is a diagram showing a pulse generator and its control configuration. 13 is an outflow control valve, 21 is a refrigerant detector, 25 is a vacuum pump, and 29 is a pulse generator.

Claims (1)

[Scope of utility model registration request] The operation time of the vacuum pump is controlled by counting the pulse signals of a pulse generator, which is composed of a magnetic material that rotates with the rotation of the vacuum pump that evacuates the refrigerant pipe, and a magnetically sensitive element is provided oppositely to the magnetic body. Upon completion of this control, the outflow control valve of the filling pipe that supplies refrigerant to the refrigerant pipe is opened, and the supply of refrigerant is controlled by a refrigerant detector that detects the refrigerant pressure in the refrigerant pipe. A refrigerant filling device configured to do this.