Resin-metal composite charge valve

Abstract

To provide a resin-metal composite charge valve including a resin valve body which can inhibit gas leakage.SOLUTION: A valve body (1) forming a charge valve (100) comprises: a resin first valve body (7) having a cylindrical housing part (12) and a resin cylindrical third valve body (9); and a metallic cylindrical second valve body (8) whose inner peripheral surface is provided with a female screw part (15a) which is threadedly engaged with a male screw part (4b) of a valve core (2). Further, a seal material (for example, an O ring (14)) is disposed between an outer peripheral surface of the second valve body (8) and an inner peripheral surface of the housing part (12).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a charge valve that is attached to the piping of an air conditioner in an automobile. [Background technology]

[0002] A technology relating to a charge valve is described in Patent Document 1. The charge valve described in Patent Document 1 has a valve core disposed inside a valve body made of an aluminum alloy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-119753 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to make automobiles lighter, the use of resin for automotive air conditioning piping is being considered. When resinifying air conditioning piping, if the charge valve attached to the piping is also made of resin, simply making the valve body out of resin will pose the following problems. There is a concern that creep will occur in the resin female thread of the valve body to which the valve core is fixed, causing the valve core to loosen due to vibration, etc. Note that creep is a phenomenon in which the amount of deformation of a material increases over time when a static load is continuously applied to the material.

[0005] In order to prevent creep from occurring in the valve core fixing portion, it is possible to make the female threaded portion of the valve body into which the valve core is screwed a metal part, and the other parts made of resin. In this case, for example, a valve body consisting of two parts, the female threaded portion made of metal and the other parts made of resin, can be manufactured by insert molding, in which a cylindrical metal part with a female threaded portion is loaded into a resin molding die and injection molded. However, this method (structure) creates a gap between the metal part and the resin part, and gas leaks occur from this gap.

[0006] An object of the present invention is to provide a resin-metal composite charge valve having a resin valve body capable of suppressing gas leakage. [Means for solving the problem]

[0007] The resin-metal composite charge valve disclosed in the present application is a charge valve comprising a valve core having a male thread portion on its outer peripheral surface and a valve body in which the valve core is disposed, the valve body comprising a first valve body made of resin having a cylindrical accommodation portion, a cylindrical second valve body made of metal that is accommodated in the accommodation portion and has a female thread portion on its inner peripheral surface that screws into the male thread portion, and a cylindrical third valve body made of resin whose base end is accommodated in the accommodation portion after the second valve body is accommodated in the accommodation portion, and a sealant is disposed between the outer peripheral surface of the second valve body and the inner peripheral surface of the accommodation portion. Effect of the Invention

[0008] According to the charge valve having the above configuration, gas leakage can be suppressed while the valve body is made of resin. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a partially cutaway cross-sectional view of a resin-metal composite charge valve according to one embodiment of the present invention. [Diagram 2]FIG. 2 is a partially cutaway cross-sectional view of a valve body that constitutes a resin-metal composite charge valve. [Diagram 3] 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 2 is a cross-sectional view of a first valve body that constitutes a valve body. [Diagram 5] FIG. 4 is a cross-sectional view of a second valve body that constitutes the valve body. [Figure 6] FIG. 4 is a cross-sectional view of a third valve body that constitutes the valve body. [Figure 7] 5 is a view corresponding to FIG. 3 and showing a modified example of a rotation preventing portion and an engaging portion that engages with the rotation preventing portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

[0011] 1, a charge valve 100 (resin-metal composite charge valve) includes a valve body 1 and a valve core 2 disposed inside the valve body 1. A cap 3 for protecting the valve core 2 is attached to an end of the valve body 1.

[0012] The valve core 2 is composed of a cylindrical valve core body 4, a rod-shaped valve member 5, and a coil spring 6 inserted into the valve member 5. The material of the valve core body 4 and the valve member 5 is, for example, brass. The inner peripheral surface side of the axial end of the valve core body 4 is an annular recess 4a, and this recess 4a serves as a valve seat. On the outer peripheral surface of the valve core body 4, a male thread portion 4b, an annular groove portion 4c, and an annular step portion 4d are provided in this order from the recess 4a side in the axial direction of the valve core body 4. An O-ring 10 is attached to the groove portion 4c as a seal material. In this embodiment, the step portion 4d is tapered toward the valve body 11 side. The step portion 4d may be a surface extending in a direction perpendicular to the axial direction of the valve core body 4. The shape of the step portion 4d is not particularly limited.

[0013] An annular valve body 11 is fixed to one end of the valve member 5, and a spring receiving portion 5a is provided at the other end. A coil spring 6 is inserted into the valve member 5 and is mounted in a compressed state between the spring receiving portion 5a and the end face of the valve core body 4. The coil spring 6 biases the valve body 11 toward the recess 4a formed in the valve core body 4. In FIG. 1, the coil spring 6 biases the valve member 5 (valve body 11) upward. Normally, the valve body 11 is fitted into the recess 4a by the biasing force of the coil spring 6. The flow path C1 on the pipe portion 13 side in the valve body 1 and the flow path C2 on the cap 3 side in the valve body 1 are in a non-communicating state (=valve closed) because the valve body 11 is fitted into the recess 4a. When the spring receiving portion 5a side of the valve member 5 is pushed into the inside of the valve core body 4 against the biasing force of the coil spring 6, the valve body 11 leaves the recess 4a. When the valve body 11 is separated from the recess 4a, the flow paths C1 and C2 are in communication (=valve open). When the flow paths C1 and C2 are in communication, gas (refrigerant gas) can flow from the flow path C2 side to the flow path C1 side (gas charge).

[0014] The valve body 1, in which the valve core 2 is disposed, is composed of three bodies: a first valve body 7 made of resin, a cylindrical second valve body 8 made of metal, and a cylindrical third valve body 9 made of resin. In other words, the valve body 1 is composed of three (three) parts. The material of the second valve body 8 is an aluminum alloy, brass, or the like. The first valve body 7 and the third valve body 9 are manufactured, for example, by injection molding of a resin material.

[0015] In this embodiment, the first valve body 7 is T-shaped and has a cylindrical storage portion 12 and a pipe portion 13. The storage portion 12 and the pipe portion 13 are communicated with each other through a cylindrical communication portion 18. The inner diameter of the communication portion 18 is smaller than the inner diameter of the storage portion 12.

[0016] The accommodation portion 12 accommodates the valve core 2 together with the second valve body 8. Connection ports 13a for resin pipes (not shown) are formed at both ends of the pipe portion 13. The ends of the resin pipes are accommodated in the connection ports 13a. The ends of the resin pipes accommodated in the connection ports 13a are fixed to the connection port 13a by, for example, welding, bonding, press fitting, or the like.

[0017] As shown in Fig. 5, the second valve body 8 is composed of a first cylindrical portion 15 and a second cylindrical portion 16. The outer diameter of the second cylindrical portion 16 is larger than the outer diameter of the first cylindrical portion 15. The inner peripheral surface of the first cylindrical portion 15 is provided with a female thread portion 15a that screws into the male thread portion 4b of the valve core 2. In addition, the outer peripheral surface of the first cylindrical portion 15 is provided with an annular groove portion 15b. As shown in Figs. 1 and 2, an O-ring 14 is fitted into this groove 15b as a seal material.

[0018] As shown in FIG. 3, the outer circumferential surface of the second cylindrical portion 16 constituting the second valve body 8 is provided with a notch portion 16a as a rotation prevention portion. In this embodiment, two notches 16a are provided in the circumferential direction of the second cylindrical portion 16 with a phase difference of 180°. As shown in FIG. 3 and FIG. 4, two protrusions 12a (engagement portions) with which these notches 16a engage are provided on the inner circumferential surface of the accommodation portion 12 of the first valve body 7. The second valve body 8 is accommodated in the accommodation portion 12 from its axial direction while aligning the position of the notch portion 16a with the position of the convex portion 12a, and the notch portion 16a engages with the convex portion 12a. The engagement of the notch portion 16a with the convex portion 12a prevents the second valve body 8 from rotating relative to the first valve body 7.

[0019] Also, the inner corner of the axial end of the second cylindrical portion 16 is the abutment portion 16b against which the step portion 4d of the valve core body 4 abuts. In this embodiment, this abutment portion 16b is tapered. If the step portion 4d is a surface extending in a direction perpendicular to the axial direction of the valve core body 4, the step portion 4d abuts against the axial end face of the second cylindrical portion 16. Therefore, if the step portion 4d is a surface extending in a direction perpendicular to the axial direction of the valve core body 4, the axial end face of the second cylindrical portion 16 is the abutment portion against which the step portion 4d abuts. In this case, the inner corner of the axial end of the second cylindrical portion 16 may or may not be tapered as in this embodiment.

[0020] After the second valve body 8 is accommodated in the accommodation portion 12, the third valve body 9 has its base end portion 17 accommodated in the end portion of the accommodation portion 12. The base end portion 17 of the third valve body 9 accommodated in the end portion of the accommodation portion 12 and the end portion of the accommodation portion 12 are fixed together by, for example, welding, bonding, press fitting, or the like.

[0021] An annular flange 9b is provided on the outer periphery of the third valve body 9. The flange 9b is provided in a portion of the third valve body 9 closer to the base end 17 in the axial direction. Furthermore, a female thread 9a into which the cap 3 is screwed is provided on the inner circumferential surface of the end of the third valve body 9 opposite the base end 17.

[0022] The valve body 1 is assembled, for example, as follows.

[0023] An O-ring 14 is fitted into a groove 15b provided on the outer circumferential surface of the first cylindrical portion 15 of the second valve body 8. The second valve body 8 with the O-ring 14 fitted thereto is fitted into the accommodation portion 12 formed in the first valve body 7, and the end face of the first cylindrical portion 15 is brought into contact with the bottom surface 12b of the accommodation portion 12. As shown in FIG. 4, the accommodation portion 12 has a small diameter portion 12c and a large diameter portion 12d, and a step surface 12e is provided at the boundary between the small diameter portion 12c and the large diameter portion 12d. The accommodation portion 12 is designed so that when the end face of the first cylindrical portion 15 is brought into contact with the bottom surface 12b of the accommodation portion 12, a gap is formed between the end face of the second cylindrical portion 16 and the step surface 12e. The bottom surface 12b of the accommodating portion 12 is a surface for positioning the second valve body 8, and a gap is formed between the end face of the second tubular portion 16 and the step surface 12e in the axial direction, thereby allowing the end face of the first tubular portion 15 to reliably abut against the bottom surface 12b of the accommodating portion 12.

[0024] Next, the base end 17 of the third valve body 9 is accommodated in the accommodation section 12 of the first valve body 7. The first valve body 7 and the third valve body 9 are made of resin, which is softer than when they are made of metal. Therefore, when the base end 17 of the third valve body 9 is accommodated in the accommodation section 12 of the first valve body 7, as shown in Figs. 1 and 2, the axial end face of the base end 17 and the axial end face of the flange 9b of the third valve body 9 abut against the axial end face of the second tubular portion 16 of the second valve body 8 and the axial end face of the accommodation section 12, respectively. Note that, in the case where the manufacturing error is somewhat large in the third valve body 9, either the axial end face of the base end 17 or the axial end face of the flange 9b abuts against the axial end face of the second tubular portion 16 or the axial end face of the accommodation section 12.

[0025] By fixing base end 17 of third valve body 9 to the end of housing portion 12 by, for example, welding, adhesive, press fitting, etc., the first valve body 7 and the third valve body 9 are fixed together and assembly of the valve body 1 is completed.

[0026] The valve core 2 is attached to the valve body 1, for example, as follows.

[0027] The valve core 2 is inserted into the valve body 1 from the end of the third valve body 9 of the valve body 1. Then, the male thread portion 4b of the valve core 2 is screwed into the female thread portion 15a of the second valve body 8 that constitutes the valve body 1. In other words, the valve core 2 is screwed into the second valve body 8. As the valve core 2 is screwed into the second valve body 8, the stepped portion 4d on the outer circumferential surface of the valve core body 4 comes into contact with the abutment portion 16b formed on the second cylindrical portion 16 of the second valve body 8 in the axial direction.

[0028] Here, the valve core body 4 is provided with a flat gripping portion 4e that can be gripped with a tool (not shown) at the axial end of the valve core 2 opposite to the valve body 11 side, making it easy to screw the valve core 2 into the second valve body 8. The worker grips the gripping portion 4e with a tool and screws the valve core 2 into the second valve body 8. When the step portion 4d provided on the valve core body 4 abuts against the abutment portion 16b formed on the second cylindrical portion 16 of the second valve body 8, the worker slightly increases the screwing force and presses the step portion 4d against the abutment portion 16b. When the step portion 4d is pressed against the abutment portion 16b, the step portion 4d is slightly bitten into the abutment portion 16b, and the male screw portion 4b of the valve core 2 and the female screw portion 15a of the second valve body 8 are firmly screwed together. That is, the valve core 2 is more prevented from loosening. Assembly of the valve core 2 to the valve body 1 is completed when the valve core 2 has been sufficiently screwed into the second valve body 8. The stepped portion 4d and the contact portion 16b also serve to determine the position of the valve core 2 relative to the second valve body 8 in the axial direction of the second valve body 8.

[0029] (effect) In the charge valve 100, the first valve body 7 and the third valve body 9 are made of resin valve bodies 1, so that the charge valve 100 is lighter than a conventional charge valve composed entirely of a metal valve body. On the other hand, the female thread portion 15a portion into which the male thread portion 4b of the valve core 2 is screwed is made of metal, so creep is suppressed from occurring in the screwed portion between the two, and the valve core 2 is prevented from loosening due to creep.

[0030] In addition, an O-ring 14 is disposed between the outer peripheral surface of second valve body 8 and the inner peripheral surface of accommodating section 12 as a sealing material, thereby making it possible to prevent gas leakage from flow path C1 on the pipe section 13 side to flow path C2.

[0031] Further, the second valve body 8 has a second cylindrical portion 16 having a rotation prevention portion (notch 16a) on its outer circumferential surface, and an engagement portion (protrusion 12a) that engages with the rotation prevention portion is provided on the inner circumferential surface of the accommodation portion 12 that constitutes the first valve body 7. Therefore, when the valve core 2 is screwed into the second valve body 8, the second valve body 8 can be prevented from rotating relative to the first valve body 7.

[0032] Incidentally, instead of using anti-rotation structures such as cutout portion 16a and protrusion 12a, the first valve body 7 and the second valve body 8 may be fixed together with an adhesive to prevent the second valve body 8 from rotating relative to the first valve body 7.

[0033] The first valve body 7 of this embodiment is T-shaped and includes the housing portion 12 and the cylindrical pipe portion 13 with the connection ports 13a of the resin pipe formed at both ends. Here, the pipe portion 13 may be omitted from the first valve body 7. In this case, the communication portion 18 is connected to the through hole portion of the resin pipe (not shown) having a through hole on the side surface by welding, bonding, press-fitting, or the like. It is not easy to connect the communication portion 18 to the through hole portion formed on the side surface of the resin pipe (not shown) by welding, bonding, press-fitting, or the like. On the other hand, it is easy to connect the end of the resin pipe to the connection ports 13a formed at both ends of the pipe portion 13 by welding, bonding, press-fitting, or the like. Therefore, by forming the first valve body 7 into a T-shape, it is possible to easily connect the resin pipe to the first valve body 7.

[0034] In this embodiment, an O-ring 14 is used as a sealant disposed between the outer circumferential surface of second valve body 8 and the inner circumferential surface of accommodating portion 12. That is, O-ring 14 is disposed as a sealant on the outer circumferential surface of first cylindrical portion 15 of second valve body 8. An adhesive may be interposed as a sealant between the outer circumferential surface of second valve body 8 and the inner circumferential surface of accommodating portion 12, and the gap between the outer circumferential surface of second valve body 8 and the inner circumferential surface of accommodating portion 12 may be sealed with the adhesive. In this case, O-ring 14 can be omitted.

[0035] The present invention is not limited to the above-described embodiments, and it is possible to combine elements of the above-described embodiments as appropriate and to make various modifications to the above-described embodiments without departing from the spirit of the present invention.

[0036] For example, the above embodiment can be modified as follows.

[0037] The number of the cutout portion 16a (protrusion 12a) serving as the anti-rotation portion may be one instead of two, or may be three or more.

[0038] Fig. 7 is a diagram corresponding to Fig. 3, showing a modified example of the anti-rotation portion and the engaging portion that engages therewith. As shown in Fig. 7, a plurality of protrusions 16c (anti-rotation portions) are provided at intervals in the circumferential direction on the outer circumferential surface of the second cylindrical portion 16 constituting the second valve body 8, and the second cylindrical portion 16 has a gear-shaped cross section. The protrusions 16c extend in the axial direction of the second cylindrical portion 16. In addition, a plurality of grooves 12f (engaging portions) that engage with the protrusions 16c are provided on the inner circumferential surface of the accommodation portion 12 of the first valve body 7. The grooves 12f extend in the axial direction of the accommodation portion 12.

[0039] In the above embodiment, the step 4d provided on the outer periphery of the valve core 2 is tapered. The step 4d does not have to be tapered. For example, it may be an annular step having a staircase shape (in other words, an L-shaped cross section).

[0040] An annular flange 9b is provided on the outer periphery of the third valve body 9. The flange 9b is not essential. However, the provision of the flange 9b stably fixes the first valve body 7 and the third valve body 9 together. [Explanation of symbols]

[0041] 1: Valve body 2: Valve core 4b: Male thread 7: First valve body 8: Second valve body 9: 3rd valve body 12: Storage unit 12a: Protrusion (engagement portion) 12f: Groove (engaging part) 13: Pipe section 13a: Connection port 14: O-ring (sealing material) 15:First cylinder part 15a: Female thread 16:Second cylinder part 16a: Notch (anti-rotation part) 16c: Convex part (anti-rotation part) 17: Proximal end 100: Charge valve (resin-metal composite charge valve)

Claims

1. A charge valve including a valve core having a male thread on its outer circumferential surface and a valve body in which the valve core is disposed, The valve body includes: a first valve body made of resin and having a cylindrical housing portion; a cylindrical second valve body made of metal that is accommodated in the accommodation portion, the second valve body having an internal thread portion that is screwed into the external thread portion and is provided on an inner circumferential surface of the second valve body; a cylindrical third valve body made of resin, the base end of which is accommodated in the accommodation portion after the second valve body is accommodated in the accommodation portion; Equipped with A sealant is disposed between an outer circumferential surface of the second valve body and an inner circumferential surface of the housing portion. Resin-metal composite charge valve.

2. The resin-metal composite charge valve according to claim 1, The second valve body includes: a first cylindrical portion having an outer peripheral surface on which the sealing material is disposed; a second cylindrical portion having a rotation prevention portion on an outer circumferential surface thereof; An engagement portion that engages with the anti-rotation portion is provided on an inner circumferential surface of the accommodation portion. Resin-metal composite charge valve.

3. The resin-metal composite charge valve according to claim 1 or 2, The first valve body is T-shaped and has the accommodation portion and a cylindrical pipe portion having connection ports for resin pipes formed at both ends. Resin-metal composite charge valve.

4. In the resin-metal composite charge valve according to any one of claims 1 to 3, The sealing material is an O-ring. Resin-metal composite charge valve.

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