JPS6311575Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an automatic refrigerant filling device.

With the recent spread of car air conditioners, there is a desire to simplify the process of filling refrigerant into air conditioners, and research and development of automatic refrigerant filling devices are being actively conducted.

The result of this effort is an automatic refrigerant filling device that automatically performs the following tasks: evacuating the air conditioner, checking for gas leaks, and filling refrigerant gas in succession.

In this conventional automatic refrigerant filling device, the refrigerant tanks are usually attached to three branch pipes separated from the refrigerant filling passage and unsealed, and the three tanks are simultaneously introduced into the refrigerant filling passage and filled.

Therefore, in the case of a normal car air conditioner, the filling amount is
Since the amount of refrigerant is approximately 700 to 900 g, only 700 to 900 g of the 1200 g of refrigerant in the three tanks (each tank has a capacity of 400 g) is actually used, and the remaining 300 to 500 g is treated as unusable and released into the atmosphere. They either release it or leave it behind and use it for other fillings. In the above case, a solution is desired from the viewpoint of recent resource saving and energy saving measures, but in the case described below, the operator has to continuously monitor the condition of the tank while working, which results in wasted work.

In view of the above-mentioned circumstances, the present invention aims to provide an excellent automatic refrigerant filling device that eliminates any waste of refrigerant.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, a pressure switch 2 is provided at any one location in the refrigerant filling passage 1.

A plurality of branch pipes 1 branched from the refrigerant filling passage.
1, 12, and 13 are equipped with refrigerant tank control solenoid valves 3, 31, and 32 that operate in conjunction with the pressure switch 2 described above, and a known refrigerant tank opener 4.

The refrigerant tanks 5, 51, and 52 are attached to the refrigerant tank unsealer 4, and preparations for refrigerant filling are made.

In addition, 6 is the evaporator, 7 is the high pressure side joint, and 8 is the evaporator.
indicates the low pressure side joint, 9 and 91 indicate the solenoid valve,
All these operate by known means.

The operation of the device of the present invention will be explained below.

The refrigerant is charged after evacuation and gas leakage check are completed using a known method. First, the solenoid valves 9 and 91 and the first refrigerant tank control solenoid valve 3 are opened.
The second refrigerant tank control solenoid valve 31 and the third refrigerant tank control pipe solenoid valve 32 are kept closed. By doing this, only the refrigerant in the first refrigerant tank 5 is filled. However, since the refrigerant tank has a capacity of 400 g, the refrigerant gradually runs out, and the pressure in the refrigerant filling passage decreases in a curved line as shown in FIG.

The characteristic of the curve in FIG. 2 is that even if the remaining amount of refrigerant decreases, the pressure does not decrease significantly, but the pressure decreases rapidly just before the refrigerant tank becomes empty. Since it is necessary to detect this pressure drop, it is desirable to install the pressure switch near the branch pipe.

The present invention focuses on the peculiarity of such a pressure drop, and picks up this sudden pressure drop with the pressure switch 2, and uses the pulse at this time to activate the first refrigerant tank control solenoid valve 3. A control means is provided which opens the second refrigerant tank control solenoid valve 31 at the same time as the second refrigerant tank is closed so that the second refrigerant tank is continuously filled with refrigerant. FIG. 4 shows an example of this control means. The specific operation of this control means will be explained with reference to the circuit diagram shown in FIG. 4. First, the contact point of the pressure switch 2 of the wiring 1 is activated, and the relay (X-1) is energized. Next, the contact of relay (X-1) of wiring 2 is activated, and the relay (X-1) is activated.
2) energize. Also, the relay for wiring 3 (X-
2) With contacts, the relay (X-2) is self-maintaining. This causes the relay (X-
2) The contact operates, solenoid valve 3 closes, and wiring 1
The solenoid valve 31 is opened by the operation of the relay (X-2) contact No. 3.

When the refrigerant reaches a fixed amount in the second refrigerant tank 51, the filling operation is stopped and the third refrigerant tank 52 can be used for charging another refrigerant machine, so that no refrigerant gas is wasted. I understand.

Second, if the refrigerant is insufficient even with the refrigerant tank 51, the empty state of the second refrigerant tank 51 is picked up by the pressure switch 2 in the same way as when the empty state of the first refrigerant tank 5 is detected; When the pressure switch 2 issues the second pulse, the second refrigerant tank control solenoid valve is closed and the third refrigerant tank control solenoid valve 32 is simultaneously opened to fill the third refrigerant tank 52 with refrigerant. It is possible to do so.

Incidentally, it is extremely effective to attach an indicator light that indicates when the refrigerant tank is empty when the pressure switch 2 is operated, because it facilitates the work of replacing the refrigerant tank. Regarding this operation, the indicator light L that indicates the sky is connected in parallel with the relay (X-2) in the circuit diagram shown in Figure 4.
This is possible by installing .

Furthermore, as shown in FIG. 3, a check valve 10 is provided in place of the first refrigerant tank control solenoid valve 3 in the branch pipe to which the first refrigerant tank 5, that is, the first refrigerant tank 5, is attached. Almost the same effect can be obtained by filling the second refrigerant tank by opening the second refrigerant tank control solenoid valve 31 provided in the second branch pipe 12 when it is empty. Since the number of solenoid valves used can be reduced, it is advantageous in terms of cost. In addition, if the refrigerant tank opener is equipped with a check valve, when the refrigerant tank is empty, the refrigerant tank control solenoid valve is not closed and the next refrigerant tank control solenoid valve is opened. It has a similar effect.

As is clear from the above description, the present invention uses refrigerant tanks one by one by providing a refrigerant tank control solenoid valve in each branch pipe and a pressure switch for detecting empty refrigerant tanks in the refrigerant filling passage. This made it possible.

Therefore, the refrigerant that conventionally required three tanks can now be filled in two tanks in normal filling operations, and the effect of eliminating wasted refrigerant is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a piping diagram showing an example of the refrigerant charging device of the present invention, Fig. 2 is a graph showing the relationship between the remaining amount of refrigerant gas and pressure, and Fig. 3 is a piping diagram of main parts showing another embodiment of the invention. , FIG. 4 is a circuit diagram showing an example of an operating circuit diagram of the refrigerant filling device of the present invention. Explanation of numbers, 1... Refrigerant filling passage, 2... Pressure switch, 11, 12, 13... Branch pipe, 3, 3
1, 32... Refrigerant tank control solenoid valve, 4... Refrigerant tank opener, 5, 51, 52... Refrigerant tank.

Claims (1)

[Claims for Utility Model Registration] (1) A pressure switch is provided in the refrigerant filling passage, and a refrigerant tank control solenoid valve and a refrigerant tank opening device are provided in a plurality of branch pipes separated from the refrigerant filling passage in conjunction with the pressure switch. When the pressure switch detects that the refrigerant tank is empty, the refrigerant tank control solenoid valve installed in the refrigerant tank branch pipe being filled is closed, and the refrigerant tank control solenoid valve installed in the branch pipe to which the unused refrigerant tank is attached is closed. An automatic refrigerant filling device comprising a control means for opening one of the solenoid valves. (2) Regarding the refrigerant tank control solenoid valves provided in each of the plurality of branch pipes mentioned above, a check valve is provided in place of the refrigerant tank control solenoid valve in the branch pipe where the refrigerant tank to be used first is installed. An automatic refrigerant filling device according to claim 1 of the utility model registration. (3) The automatic refrigerant filling device according to claim 1, characterized in that the automatic refrigerant filling device is provided with an indicator light that indicates when the refrigerant tank is empty when the pressure switch is activated. Device.