Additive injection device and joint used therefor

Abstract

Provided are a compact and highly safe additive injection device that does not mix air into the refrigerant system of a car air conditioner, and a joint that can ensure the safety of the additive injection device. 【Solution means】The additive injection device E includes a joint 1 having a connection means with a service port of a refrigerant for a car air conditioner at the front end and having a first check valve, and a connection part 20 that serves as a connection means with the rear end of the joint, and includes a syringe 2 that can be filled with an additive M for a car air conditioner, and a plunger 3 that is slidable on the inner wall of the syringe. The joint includes an elastic body that biases the first check valve in the closing direction rearward.

Description

Technical Field

[0001] The present invention relates to an additive injection device for injecting an additive into a refrigerant circuit of a car air conditioner and a joint used therefor.

Background Art

[0002] Conventionally, as an additive supply device for injecting an additive into a refrigerant circuit of a car air conditioner, refrigerant supply means for supplying refrigerant to the circulation path through a service port disposed in the circulation path through which the refrigerant of the car air conditioner circulates, a cylindrical cartridge filled with a liquid additive, a first connector having one end connected to the base end side of the cartridge and the other end connected to the refrigerant supply means, and a second connector having one end connected to the tip end side of the cartridge and the other end connected to the service port, wherein the second connector has a hose portion, a joint provided at the end of the hose portion on the service port side, a discharge portion provided at the end of the hose portion on the cartridge side, and a check valve disposed between the discharge portion and the cartridge, the check valve closing to regulate the supply of the refrigerant and the additive from the service port side to the cartridge side, while opening when the refrigerant is supplied from the refrigerant supply means at a pressure equal to or higher than a predetermined value to supply the refrigerant and the additive to the circulation path through the service port. An additive supply device for a car air conditioner is known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the additive supply device for the automotive air conditioner is configured to include a refrigerant supply means (service cylinder) that supplies refrigerant to the circulation path from the service port via various components, the overall length becomes large, which is inconvenient.

[0005] Also, the longer the overall length of the additive supply device for the automotive air conditioner, the easier it is for air to accumulate inside, and there is concern about the intrusion of air into the refrigerant system of the air conditioner.

[0006] Furthermore, in the above Patent Document 1, although the additive supply device for the automotive air conditioner includes an independent check valve (there is a description that it may have any configuration), the specific configuration is not disclosed, and it is not guaranteed that the performance of appropriately preventing backflow by the check valve can be exerted.

[0007] The present invention has been made in view of the above circumstances, and an object of the invention is to provide an additive injection device that can prevent the intrusion of air into the refrigerant system of the automotive air conditioner, is compact and highly safe, and to provide a joint that can ensure the safety of the additive injection device.

Means for Solving the Problems

[0008] The present invention provides an additive injection device including a joint having connection means to a service port for refrigerant for an automotive air conditioner at the front end and having a first check valve, a syringe having connection means to the rear end of the joint and capable of being filled with an additive for an automotive air conditioner, and a plunger slidable on the inner wall of the syringe, wherein the joint includes an elastic body that biases the first check valve in a closing direction (i.e., rearward) as means for solving the above problems.

Effects of the Invention

[0009] According to the present invention, an additive injection device is provided with a joint having connection means to a service port for a refrigerant of a car air conditioner at the front end and having a first check valve, a syringe having connection means to the rear end of the joint and capable of being filled with an additive for a car air conditioner, and a plunger slidable on the inner wall of the syringe. Therefore, in a state where the joint and the syringe are connected, by pushing the plunger forward, the additive for the car air conditioner in the syringe is sent to the front end of the joint, so that the air inside the syringe and the joint can be purged. In this state, by connecting to the service port of the car air conditioner, it is possible to prevent air from entering the refrigerant system of the car air conditioner.

[0010] Note that the connection means to the joint in the syringe can be configured to be directly provided on the syringe, and also includes the meaning of connecting using a separate tubular member. By connecting using a tubular member, even when the space around the service port is narrow and the syringe or the plunger interferes with other objects and injection cannot be performed, injection can be enabled. Also in this case, by pushing the plunger forward and sending the additive to the front end of the joint through the tubular member, the internal air can be purged. In this state, by connecting to the service port of the car air conditioner, it is possible to prevent air from entering the refrigerant system of the car air conditioner.

[0011] Further, according to the present invention, since it is composed of a joint, a syringe having connection means to the joint, and a plunger, a compact configuration can be realized as a whole.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0013] The present invention has, at the front end, a connecting means to a service port for the refrigerant of a car air conditioner in a vehicle and a joint having a first check valve, a syringe having a connecting means to the rear end of the joint and capable of filling an additive for a car air conditioner, and a plunger slidable on the inner wall of the syringe, and the joint can be an additive injection device provided with an elastic body that biases rearward in a direction to close the first check valve (first configuration). Here, the connecting means to the rear end of the joint means

[0014] According to the first configuration described above, since the additive injection device includes a joint having a connecting means to a service port for the refrigerant of a car air conditioner in a vehicle and a first check valve at the front end, a syringe having a connecting means to the rear end of the joint and capable of filling an additive for a car air conditioner, and a plunger slidable on the inner wall of the syringe, in a state where the joint and the syringe are connected, by pushing the plunger forward, the additive for the car air conditioner in the syringe is sent to the front end of the joint, so that the air inside the syringe and the joint can be purged. In this state, by connecting to the service port of the car air conditioner, it is possible to prevent air from entering the refrigerant system of the car air conditioner.

[0015] And, the joint is provided with an elastic body that biases the first check valve in a direction to close it. When reverse flow of the refrigerant occurs, the first check valve immediately operates due to the biasing of the elastic body, thus preventing the blowing out of the refrigerant and ensuring safety.

[0016] Further, according to the present invention, in addition to the above first configuration, the joint includes a pressing body for releasing the second check valve of the service port by pressing, the first check valve disposed behind the pressing body, and the elastic body provided between the pressing body and the first check valve, and the elastic body is disposed in an accommodation space formed by the pressing body and the first check valve (second configuration).

[0017] According to the above second configuration, since the joint includes a pressing body for releasing the second check valve of the service port by pressing, the first check valve disposed behind the pressing body, and the elastic body provided between the pressing body and the first check valve, and the elastic body is disposed in an accommodation space formed by the pressing body and the first check valve, the elastic body is guided by the holding space, the expansion and contraction operation of the elastic body becomes accurate, and the pressing body, the elastic body, and the first check valve can be formed compactly. Therefore, the volume inside the joint can be reduced, so that almost no additive remains after injection, air mixing into the refrigerant system of the car air conditioner can be prevented, and proper and accurate injection of the air conditioner can be ensured.

[0018] Further, according to the present invention, it can be the joint used in any of the above additive injection devices (third configuration).

[0019] According to the above third configuration, by using the joint having the above configuration, it is possible to contribute to the provision of an additive injection device having the above effects.

Example

[0020] Hereinafter, with reference to the drawings, an additive injection device according to an embodiment of the present invention will be described. The same or corresponding parts in the drawings are denoted by the same reference numerals and their descriptions will not be repeated. For the sake of clarity of explanation, in the drawings referred to below, the configurations are shown in a simplified or schematic manner, or some of the constituent members are omitted. Also, the dimensional ratios of the constituent members shown in each figure do not necessarily represent the actual dimensional ratios. Also, for the sake of explanation, the left side in FIG. 1 (i.e., the joint side of the additive injection device) is taken as the front (F), and the right side (i.e., the plunger side) is taken as the rear (B).

[0021] As shown in FIG. 1, the additive injection device E according to Embodiment 1 of the present invention includes a joint 1 having a first check valve 10 inside, a syringe 2 that can be filled with an additive M for a car air conditioner (hereinafter, additive M), and a plunger 3 that slides on the inner wall of the syringe 2. Here, the syringe 2 can be configured to be filled with the additive M in advance. Further, it consists of a syringe 2 having a lid at the front end and a plunger 3, and is used as a single structural unit with the additive M enclosed inside the syringe 2. During use, the lid at the front end of the syringe 2 is removed and the joint 1 is connected to form the additive injection device E.

[0022] As shown in FIG. 2(a), the joint 1 constituting the additive injection device E according to Embodiment 1 of the present invention includes a joint body 10 that forms a flow path for the additive M, a sleeve 11 that covers the outer periphery of the front end side of the joint body 10, a first check valve 12 disposed in the flow path inside the joint body 10, a pressing body 13 disposed coaxially with the first check valve 12 and forward, a coil spring 14 that is an elastic body disposed between the first check valve 12 and the pressing body 13, a sleeve spring 110 that biases the sleeve 11 forward, and a steel ball 111 that can protrude into and out of the flow path as the sleeve 11 moves back and forth.

[0023] The joint body 10 has a rear-side connection part 16 protruding from the rear end face. An external thread is formed on the outer periphery of the rear-side connection part 16. A flow path 15 for the additive M is formed in the center from the rear-side connection part 16 to the front end of the joint body 10. The flow path 15 on the front half side of the joint body 10 is formed with a large diameter in accordance with the size of the service port S (low-pressure side port) to be inserted. The flow path 15 on the rear half side of the joint body 10 is formed with a diameter adapted to the first check valve 12.

[0024] A ball retaining hole 100 for retaining a ball 111 is provided on the front-side side surface of the joint body 10. The ball 111 is retained in the ball retaining hole 100. In the normal state, the sleeve 11 is biased forward by a sleeve spring 110. At this time, the ball 111 is pressed inward by the sleeve 11 and protrudes from the flow path. When the sleeve 11 is retracted, the ball 111 sinks into the ball retaining hole 100, and the service port S (see Fig. 3.) of the joint body 10 can be inserted and removed.

[0025] The first check valve 12 held in the joint body 10 allows the additive M to pass from the rear of the joint and closes against the refrigerant flowing in the reverse direction. A pressing body 13 arranged coaxially with the first check valve 12 and in front of the first check valve 12 is fixed to the joint body 10.

[0026] The pressing body 13 presses the tip S100 of the second check valve S10 (insect valve) provided at the tip of the service port S to open the second check valve S10. A pressing body side recess 130 for holding and guiding a coil spring 14 is formed on the rear end side of the pressing body 13. A hole 131 for passing the additive is provided on the side surface of the pressing body 13.

[0027] As shown in FIGS. 2(b) to 2(e), the first check valve 12 includes a check valve side recess 120 on the front end side and a flow path forming groove 121 for forming a flow path, and an O-ring 122 is fitted into a recess provided annularly in the circumferential direction on the rear end side.

[0028] As shown in FIG. 2(a), the rear end of the coil spring 14 is held in the check valve side recess 120 on the front end side. As described above, in the normal state, since the pressing body 13 is fixed to the joint body 10, the first check valve 12 is biased rearward by the coil spring 14, and the O-ring 122 on the rear end side closes the flow path.

[0029] As described above, the accommodation space for the coil spring 14 is formed by the pressing body 13 and the first check valve 12. The accommodation space does not necessarily have to be a sealed space, and a part thereof may be open.

[0030] By forming the accommodation space, the operation of the coil spring 14 is stabilized, and the space inside the joint 1 can be reduced. By reducing the space inside the joint, the loss of the additive M injected from the syringe 2 can be reduced. Also, the risk of air entering the refrigerant system of the car air conditioner can be reduced.

[0031] The syringe 2 constituting the additive injection device E according to the first embodiment of the present invention is a cylindrical body having a connection portion 20 serving as a connection means with the joint at the front end and a syringe flange portion 21 at the rear end. The connection portion 20 is provided with a female screw and can be screwed with the male screw of the rear portion side connection portion 16 of the joint.

[0032] The plunger 3 constituting the additive injection device E according to the first embodiment of the present invention is a solid cylindrical member and is provided with a plunger flange portion 30 at the rear end. The outer peripheral portion of the plunger 3 is slidably provided on the inner wall of the syringe.

[0033] As described above, for the structural unit composed of the syringe 2 filled with the additive M inside and having a lid (not shown) at the front end, and the plunger 3, the lid (not shown) at the front end is removed, and the rear connection part 16 of the joint 1 and the connection part 20 of the syringe 2 are connected to form the structure of the first embodiment (see Fig. 1).

[0034] In this state, with the front end side facing upward, by pushing the plunger 3 into the syringe 2, the additive M is pumped to the front end side (i.e., upward), the check valve in the joint 1 is opened, and the additive M reaches the front end of the joint body 10. By this operation, the air in the syringe 2 and the joint 1 is purged.

[0035] With the air purged, as shown in Fig. 4, the front end of the joint 1 is connected to the service port S. The second check valve of the service port is opened by being pressed by the pressing body 13 in the present invention. By further pushing the plunger into the syringe 2, the additive M can be injected into the refrigerant system of the car air conditioner.

Embodiment

[0036] In the above first embodiment, the connection part of the syringe 2 and the rear connection part 16 of the joint 1 are directly connected. However, in the second embodiment, as shown in Fig. 5, a separate tubular member 22 is interposed between the connection part 20 of the syringe 2 and the rear connection part 16 of the joint 1. In the present invention, this tubular member 22 is treated as a connection means that is part of the syringe 2 together with the connection part 20.

[0037] The tubular member 22 has a structure that can be connected to the rear connection part 16 of the joint 1 at the front end (specifically, a female screw that can be screwed with the male screw of the rear connection part 16), and a structure that can be connected to the connection part 20 of the syringe 2 at the rear end (specifically, a male screw that can be screwed with the female screw of the connection part 20).

[0038] Similar to Example 1, for the structural unit consisting of a syringe 2 filled with additive M inside and having a lid at the front end and a plunger 3, the lid at the front end is removed and connected to the rear end of the tubular member 22. Also, the rear connection part 16 of the joint 1 and the front end of the tubular member 22 are connected. Thus, the configuration of Example 2 is formed.

[0039] In this state, with the front end side facing upward, by pushing the plunger 3 into the syringe 2, the additive M is pumped to the front end side (i.e., upward) through the tubular member 22, and the first check valve 12 in the joint 1 is opened, reaching the front end of the joint body 10. By this operation, the air in the syringe 2, the tubular member 22, and the joint 1 is purged.

[0040] In the state where the air has been purged, also in Example 2, the front end of the joint 1 is connected to the service port S. The second check valve S10 of the service port S is opened by being pressed by the pressing body 13 in the present invention. By further pushing the plunger 3 into the syringe 2, the additive M can be injected into the refrigerant system of the car air conditioner.

[0041] As described above, according to the present invention, in the state where the joint 1 and the syringe 2 are connected, air is purged and then connected to the service port S, so that the mixing of air into the refrigerant system of the car air conditioner can be prevented, and proper and accurate injection into the air conditioner can be ensured. And the joint is provided with an elastic body that biases the first check valve in the closing direction inside the joint body. When the reverse flow of the refrigerant occurs, the first check valve immediately operates due to the biasing of the elastic body, thus preventing the refrigerant from blowing out and ensuring safety.

Explanation of Reference Numerals

[0042] E Additive injection device M Additive S Service port S10 Second check valve S20 Pipe 1 Joint 10 Joint body 100 Ball retaining hole 11 Sleeve 110 Spring for sleeve 111 Steel ball 12 First check valve 120 Check valve side recess 13 Pressing body 130 Pressing body side recess 14 Coil spring (elastic body) 15 Flow path 16 Rear side connection part 2 Syringe 20 Connection part 21 Syringe flange part 22 Tubular member 3 Plunger 30 Plunger flange part

Claims

1. A joint having at its front end a connection means to a service port for a refrigerant of a car air conditioner and having a first check valve, a syringe having a connection means to the rear end of the joint and capable of being filled with an additive for a car air conditioner, and a plunger slidable on the inner wall of the syringe, wherein the joint includes an elastic body that biases rearward in a direction to close the first check valve, the additive injection device being characterized thereby.

2. The joint is a pressing body for releasing, by pressing, a second check valve of the service port, the first check valve disposed rearward of the pressing body, the elastic body being provided between the pressing body and the first check valve, The additive injection device according to claim 1, wherein the elastic body is disposed in an accommodation space formed by the pressing body and the first check valve.

3. The joint used in the additive injection device according to claim 1.

4. The joint used in the additive injection device according to claim 2.

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