Pipe connection component, and manufacturing method for pipe connection component

Abstract

To provide a pipe connection component capable of suppressing a production cost while ensuring dimension accuracy, to reduce burden on an environment, and a manufacturing method for a pipe connection component.SOLUTION: A pipe connection component 100 is configured to connect a pipe for supplying lubricant or liquid other than the lubricant. The pipe connection component 100 is provided with a male screw part 20 for fixing other pipe connection components on an outer surface of the body part 10, and / or a female screw part 12 for fixing the other pipe connection components on an inner surface of the body part 10, and is made of duralumin or a lead-free, free-cutting aluminum alloy.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a pipe connection component for connecting pipes and a method for manufacturing the pipe connection component. [Background technology]

[0002] As a material used for conventional piping parts, for example, brass as described in Patent Document 1 has been evaluated in terms of machinability, material price, etc., and has been widely used. In particular, in the field of piping connection parts that connect piping used in lubrication systems that supply lubricants to industrial machines, etc., the diameter of the piping to be connected is often small, such as 4 mm, 6 mm, or 8 mm, and the equipment in which the piping is installed is often placed in a narrow space, so there has been a demand for miniaturization of the piping connection parts. Furthermore, since high dimensional accuracy is required as the parts are miniaturized, brass, which has excellent machinability and is easy to improve dimensional accuracy, has been used almost exclusively in the field of lubrication systems. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2019-508584 Summary of the Invention [Problem to be solved by the invention]

[0004] However, most of the brasses that have been used conventionally contain lead for reasons such as improving machinability, and it is difficult to continue using them considering the burden on the environment, etc. Furthermore, with the recent increase in material prices, even when using brass, which has traditionally been considered to be a relatively inexpensive material, the material price has become a factor that pushes up manufacturing costs, and there was room for improvement in these respects.

[0005] An object of the present disclosure is to provide a pipe connection component that can reduce manufacturing costs while ensuring dimensional accuracy and reduce the burden on the environment, and a manufacturing method for the pipe connection component. [Means for solving the problem]

[0006] In order to solve the above problems, the piping connection part of the present disclosure comprises: [1] A piping connection part for connecting a piping for supplying a lubricant or a liquid other than a lubricant, A male thread portion for fixing other piping connection parts is provided on the outer surface of the main body, and / or a female thread portion for fixing other piping connection parts is provided on the inner surface of the main body, It is characterized by being made of duralumin or a lead-free free-cutting aluminum alloy.

[0007] In addition, the piping connection part of the present disclosure is [2] In the configuration described in [1] above, it is preferable that a male thread portion for fixing other piping connection parts is provided on the outer surface of the main body portion, and the male thread portion has a coating portion covered with a sealant containing a fluororesin.

[0008] In addition, the piping connection part of the present disclosure is [3] In the configuration described in [2] above, it is preferable that the corner of the tip of the male thread portion is chamfered, and the tip end of the coating portion is located axially within one revolution of the thread from the chamfered corner toward the base end.

[0009] In addition, the piping connection part of the present disclosure is [4] In the configuration described in [1] above, it is preferable that the inner surface of the cylindrical main body portion is provided with the female thread portion capable of threadedly engaging with the male thread portion of another piping connection part from both axial sides, and that the outer peripheral surface of the main body portion excluding both axial ends is provided with D-cuts at four circumferential positions when viewed in the axial direction.

[0010] In addition, the piping connection part of the present disclosure is [5] In the configuration described in any one of the above [1] to [4], it is preferable that a coating is formed on the surface of the main body by electroless nickel plating.

[0011] In order to solve the above-mentioned problems, the manufacturing method of the pipe connection part of the present disclosure includes: [6] A method for manufacturing a pipe connection part according to the above [2] or [3], preparing a coating liquid containing a fluororesin and a solvent; Applying the coating liquid to a predetermined axial position of the male thread portion; drying the applied coating liquid; baking the dried coating liquid; The present invention is characterized by comprising:

[0012] In addition, the manufacturing method of the pipe connection part of the present disclosure includes: [7] In the configuration described in [6] above, it is preferable that the baking treatment includes a heat treatment for 30 minutes in a furnace having an internal temperature of 130° C. or higher and 160° C. or lower. Effect of the Invention

[0013] According to the present disclosure, it is possible to provide a pipe connection component that can reduce manufacturing costs while ensuring dimensional accuracy and reduce the burden on the environment, and a method for manufacturing a pipe connection component. [Brief description of the drawings]

[0014] [Figure 1] 1 is a front cross-sectional view of a pipe connection part according to a first embodiment of the present disclosure. [Diagram 2] 1 is a plan view of a pipe connection part according to a first embodiment of the present disclosure. [Diagram 3] FIG. 2 is a left side view of the pipe connection part according to the first embodiment of the present disclosure. [Figure 4] 1 is a perspective view of a pipe connection part according to a first embodiment of the present disclosure; FIG. [Figure 5A]FIG. 11 is a diagram showing the relationship between the positioning angle of the male thread portion and the tightening torque when duralumin is used for the female thread portion. [Figure 5B] FIG. 13 is a diagram showing the relationship between the positioning angle of the male thread portion and the tightening torque when brass is used for the female thread portion. [Figure 6] 4 is a flowchart showing the steps of a manufacturing method of a pipe connection component according to a first embodiment of the present disclosure. [Figure 7] FIG. 4 is a front cross-sectional view of a pipe connection part according to a second embodiment of the present disclosure. [Figure 8] FIG. 4 is a right side view of a pipe connection part according to a second embodiment of the present disclosure. [Figure 9] 1A to 1C are diagrams showing an example of a combination of pipe connection parts according to the first and second embodiments of the present disclosure. [Figure 10] FIG. 11 is a front cross-sectional view of a pipe connection part according to a third embodiment of the present disclosure. [Figure 11] FIG. 11 is a right side view of a pipe connection part according to a third embodiment of the present disclosure. [Figure 12] FIG. 11 is a front cross-sectional view of a pipe connection part according to a fourth embodiment of the present disclosure. [Figure 13] 13 is a cross-sectional view taken along the line AA in FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a pipe connection part 100 according to a first embodiment of the present disclosure will be described in detail with reference to the drawings (FIGS. 1 to 4).

[0016] The pipe connection part 100 according to this embodiment is a pipe connection part for connecting pipes, which is used mainly in a lubrication system for supplying lubricant to industrial machines, etc. As shown in Fig. 1 to Fig. 4, the pipe connection part 100 has a female thread part 12 formed downward from the upper end part of a cylindrical part 11 of a main body part 10 made of duralumin (material code: A2017), and a male thread part 20 extending from the side surface of the cylindrical part 11 toward the left in Fig. 1. That is, the pipe connection part 100 is also called an elbow adapter, and is an adapter for connecting a flow path of a lubricant while changing the direction in the direction of a central axis O1 of the male thread part 20 that is perpendicular to the pipe 40 (see Fig. 9) that is attached to the female thread part 12.

[0017] In this specification, claims, and drawings, the term "lubricant" includes both lubricating oils whose main component is oil such as mineral oil, synthetic oil, vegetable oil, or animal oil, and greases whose viscosity is increased by adding a thickener to the lubricating oil. The up-down direction of the pipe connection part 100 is the up-down direction (Z direction) in the front view of FIG. 1, and is the direction perpendicular to the paper surface in the plan view of FIG. 2. The front-rear direction of the pipe connection part 100 is the left-right direction (X direction) in the front view of FIG. 1, and is the left-right direction (X direction) in the plan view of FIG. 2. The width direction of the pipe connection part 100 is the direction perpendicular to the paper surface in the front view of FIG. 1 (Y direction), and is the up-down direction in the plan view of FIG. 2.

[0018] The central axis O1 of the pipe connection part 100 extending in the front-rear direction (X direction) is the central axis of the male thread portion 20 extending rearward from the cylindrical portion 11. Moreover, the central axis O2 extending in the up-down direction (Z direction) is the central axis of the female thread portion 12 extending downward from the upper end of the cylindrical portion 11.

[0019] The accompanying drawings of the present disclosure are drawn to equal scale in the up-down direction (Z direction), front-rear direction (X direction), and width direction (Y direction), and the aspect ratio of the pipe connection part 100 in the drawings represents the aspect ratio of the pipe connection part 100 of one embodiment of the present disclosure. However, the configuration, shape, dimensional ratio, etc. of the pipe connection part 100 in the accompanying drawings are merely one embodiment of the present disclosure. The present invention should be interpreted based on the wording of the claims, and is not limited to the configuration, shape, dimensional ratio, etc. shown in the drawings.

[0020] In this embodiment, the female thread portion 12 extending downward (to the negative Z direction) from the upper end of the cylindrical portion 11 is configured to be threadedly engaged with a male thread portion 110 (see FIG. 7) provided on another pipe connection part (for example, a pipe connection part 200 according to a second embodiment described later). The female thread portion 12 is formed as a parallel thread, and is connected at its lower end to a fitting cylindrical portion 14 into which the outer circumferential surface of the pipe 40 (see FIG. 9) fits.

[0021] On the other hand, the male thread portion 20 extending rearward (negative side in the X direction) from the side of the tubular portion 11 is threadedly engaged and fixed to a lubrication point of industrial machinery or the like to which lubricant is supplied, a lubricant discharge portion in a lubrication device, a female thread portion 312 provided on a piping connection part 400 (coupling) according to a fourth embodiment described below, a tapered female thread portion of another elbow adapter, a distributor that branches the flow path of the lubricant, etc.

[0022] 1, a liquid flow path 24 that communicates with the female thread portion 12 and the fitting tubular portion 14 is provided inside the male thread portion 20. The liquid flow path 24 is provided so as to incline upward from the lower end of the fitting tubular portion 14 toward the vicinity of the central axis O1 of the rear end of the male thread portion 20.

[0023] The male thread portion 20 of the pipe connection part 100 according to this embodiment is a tapered thread that narrows toward the tip (rear, in the negative X direction). The nominal diameter of the male thread portion 20 is R1 / 8 as defined by the pipe tapered thread standard (JIS B 0203:1999). By making the male thread portion 20 a tapered thread, it is possible to improve the liquid-tightness of the joint with the female thread portion.

[0024] In this embodiment, the male thread portion 20 is formed to have a reference diameter of the tapered thread at an axial position that is the center of the thread length L from the base end to the tip end (including the corner portion 22) of the male thread portion 20 shown in Fig. 2. By controlling the diameter of the tapered thread in this manner, it is possible to suppress variation in the axial position of the male thread portion 20 when engaged with the female thread portion, and therefore it is possible to stabilize the sealing effect in the thread portion.

[0025] In this embodiment, the male thread portion 20 is formed by a thread cutting tip with a flat edge, which is a side edge for rounding off the apex of the thread. This configuration removes burrs from the apex of the thread, reducing frictional resistance when the male thread portion is threadedly engaged with the female thread portion of another piping connection part, and making it less likely that galling will occur when the thread is tightened.

[0026] In this embodiment, the material of the pipe connection part 100 is duralumin (material code: A2017), which is a high-strength aluminum alloy obtained by adding copper and magnesium to aluminum. As shown in Table 1, duralumin has a tensile strength of about 1.25 to 1.3 times that of conventionally used brass (material code: C3604), and it is considered that duralumin has a torsional strength indicating resistance to fastening torque of about 1.25 to 1.3 times that of brass. Therefore, by forming the pipe connection part 100 from duralumin, the wall thickness of the pipe connection part 100 can be thinned and made smaller. This reduces the amount of material used, and reduces material costs and processing costs. In addition to duralumin and brass, the following Table 1 lists the material properties of four types of lead-free free-cutting aluminum alloys that can be used as substitutes for duralumin. CB156, CB256, KS26, and KS28S in Table 1 are all model names of lead-free free-cutting aluminum alloys manufactured by UACJ Corporation. Although the density of KS28S has not been measured, it is considered to be almost the same as that of KS26 based on its components, etc. It can be seen that when any of the lead-free free-cutting aluminum alloys in Table 1 is used instead of duralumin as the material for the pipe connection part 100, the same effect as that of duralumin can be obtained.

[0027] [Table 1]

[0028] Also, as shown in Table 1, duralumin and lead-free free-cutting aluminum alloys have a density that is about one-third that of brass, so assuming that the material price per unit weight is roughly the same, the material cost to manufacture parts of the same shape is about one-third that of brass. In addition, the weight of parts of the same shape will also be about one-third. This reduces the manufacturing cost of parts and significantly reduces the weight of lubrication systems that use the parts.

[0029] The lead-free free-cutting aluminum alloy that can be used instead of duralumin is not limited to those exemplified in Table 1. It may be other lead-free free-cutting aluminum alloys that do not contain lead, have higher tensile strength and shear strength than brass (e.g., 0.9 times or more than duralumin), have a sufficiently small density of about one-third that of brass (e.g., 1.1 times or less than the density of duralumin), have machinability equivalent to that of duralumin (e.g., an average machinability index of 0.9 times or more than that of duralumin), and contain aluminum, copper, and bismuth as components. In addition, by using duralumin or a lead-free free-cutting aluminum alloy as the material for the pipe connection part 100, it becomes easier to comply with the RoHS Directive.

[0030] However, when duralumin or the above-mentioned lead-free free-cutting aluminum alloy is used as a substitute for duralumin as the material of the pipe connection part 100, the frictional force between the threaded portions increases, and depending on the tightening torque, galling may occur. As a result of intensive research by the inventors, it was found that by applying a sealant to the outer surface of the male threaded portion 20 that improves the sealing performance of the threaded portion, the frictional force acting between the threaded portions can be reduced, thereby reducing the tightening torque, making galling less likely to occur.

[0031] In this embodiment, as shown by the thick line in Fig. 2, the male thread portion 20 has a coated portion CT covered with a sealant containing a fluororesin. In this embodiment, the coated portion CT covers a part of the region of the thread length L from the base end to the tip end (including the corner portion 22) of the male thread portion 20 shown in Fig. 2. More specifically, the tip end of the coated portion CT is located axially within one revolution of the thread from the C-chamfered corner portion 22 toward the base end. In other words, the axial distance L1 in Fig. 2 is equal to or less than the pitch P of the male thread portion 20. In addition, the axial distance L2 from the base end of the male thread portion 20 to the base end side end of the coated portion CT is equal to or less than one third of the thread length L.

[0032] The coating portion CT used in this embodiment is a sealant containing fluororesin and a solvent. In this embodiment, the sealant is "Eight Seal AC-505" manufactured by Taihei Kasei Co., Ltd. As described later, this "Eight Seal AC-505" is applied to a predetermined axial position on the outer surface of the male thread portion 20, dried, and then baked to form a seal surface that is difficult to peel off. Conventionally, a seal tape was wrapped around the outer surface of the male thread portion 20, or a liquid sealant was applied thereto. However, there was a tendency to avoid sealing up to the tip of the male thread portion 20, because the seal tape wrapped around the tip of the male thread portion 20 was torn off during screw fastening and entered the pipe, or the liquid sealant attached to the tip before hardening dripped into the pipe. In this embodiment, a sealant containing fluororesin and a solvent is applied to a predetermined axial position of the male thread portion 20, dried, and then baked, so that the coating portion CT can be firmly attached to the extent that it does not peel off even when scratched or rubbed with a fingernail. Therefore, the coating portion CT can be extended from the chamfered corner 22 of the male thread portion 20 to an axial position within one revolution of the thread toward the base end side. Therefore, the sealant containing fluororesin can be applied to the vicinity of the tip of the male thread portion 20 to ensure a seal with the female thread portion of another piping connection part and effectively reduce frictional force.

[0033] The inventors confirmed the relationship between the positioning angle [degrees] of the male thread and the tightening torque [N·m] when duralumin is used for the female thread and duralumin and brass are used for the male thread by measuring the test sample. When duralumin is used for the male thread and the coating portion CT is not provided, the tightening torque increases significantly with an increase in the positioning angle [degrees] of the male thread compared to when brass is used for the male thread, and galling may occur. On the other hand, when duralumin is used for the male thread and the coating portion CT is provided, as shown in FIG. 5A, the increase in the tightening torque with an increase in the positioning angle [degrees] is effectively suppressed compared to when brass is used for the male thread and the coating portion CT is not provided, and the tightening torque required to rotate the male thread by the same rotation angle is reduced compared to when brass is used. This is considered to be because not only the coating portion CT adopted in this embodiment provides a sealing effect, but also the inclusion of fluororesin or the like provides an effect of effectively reducing the friction force between the male thread and the female thread. In Figure 5A, the tightening torque at the positioning angle [degrees]: 0 degrees is 5 [N·m] for the duralumin male thread and 7 [N·m] for the brass one. The frictional force between the duralumin male thread with the coating CT and the female thread is kept small, and when the tightening torque to reach the specified screw engagement position was investigated in advance, it was about 7 [N·m] for the brass male thread and about 5 [N·m] for the duralumin male thread. Therefore, the tightening torque at the positioning angle [degrees]: 0 degrees was adopted as follows: duralumin male thread: 5 [N·m], brass male thread: 7 [N·m]. The same applies to Figure 5B.

[0034] In addition, since it is considered that the male thread portion 20 of the pipe connection part 100 of this embodiment is often used in combination with the female thread portion of another pipe connection part made of brass, the relationship between the positioning angle [degrees] of the male thread portion and the tightening torque [N·m] when the female thread portion is made of brass and the male thread portion is made of duralumin and brass was also confirmed by actual measurement of a test sample. When the male thread portion is made of duralumin and the coating portion CT is not provided, the tightening torque increases significantly with an increase in the positioning angle [degrees] of the male thread portion compared to when the male thread portion is made of brass, and galling may occur. On the other hand, when the male thread portion is made of duralumin and the coating portion CT is provided, as shown in FIG. 5B, the increase in the tightening torque with an increase in the positioning angle [degrees] is effectively suppressed compared to when the male thread portion is made of brass and the coating portion CT is not provided, and the tightening torque required to rotate the male thread portion by the same rotation angle is reduced compared to when it is made of brass. It is considered that this result is also due to the fact that the coating portion CT contains fluororesin or the like, thereby effectively reducing the friction force between the male thread portion and the female thread portion.

[0035] The pipe connection part 100 according to the present embodiment has been described as being provided with the coating portion CT on a piece formed by cutting duralumin or a lead-free free-cutting aluminum alloy, but is not limited to this embodiment. For example, a coating may be formed by electroless nickel plating on the surface of the pipe connection part 100 formed by cutting, and then the coating portion CT may be provided on the electroless nickel plating. With this configuration, it is possible to effectively prevent the surface of the pipe connection part 100 made of duralumin or lead-free free-cutting aluminum from corroding due to contact with a liquid agent (such as water) other than the lubricant.

[0036] Electroless nickel plating has the advantage that it can provide plating of uniform thickness because it deposits the plating by chemical reaction without using electricity, and it is easy to maintain the dimensional accuracy of the pipe connection part 100. Furthermore, by providing an electroless nickel plating film, it is possible to improve the corrosion resistance of the member as well as the wear resistance, hardness, etc.

[0037] The thickness of the electroless nickel plating is preferably the minimum thickness required to inhibit corrosion of the surface of the pipe connection part 100. In addition, the thickness of the electroless nickel plating film is preferably within a range that allows the male threaded portion 20 and / or the female threaded portion 12 provided on the main body 10 to be satisfactorily threadedly engaged with the threaded portions of other pipe connection parts.

[0038] Furthermore, when a thick electroless nickel plating coating is applied to reliably suppress corrosion of the surface of the pipe connection part 100 under harsh operating conditions, it is desirable to form the diameter of the male thread portion 20 smaller and / or the diameter of the female thread portion 12 larger when cutting is completed, so that the male thread portion 20 and / or the female thread portion 12 after the thick electroless nickel plating coating is applied can threadably engage with the threads of other pipe connection parts.

[0039] When the pipe connection part 100 according to this embodiment is used for connecting pipes for supplying a liquid agent other than a lubricant in a lubrication system for industrial machinery, for example, in a medical machine, the above-mentioned electroless nickel plating coating can be provided on the surface of the pipe connection part 100 to effectively prevent the surface of the pipe connection part 100 from corroding due to contact with a liquid agent such as water. The electroless nickel plating coating provided on the surface of the pipe connection part 100 can also be applied to the pipe connection parts of the second to fourth embodiments described below.

[0040] Next, a method for manufacturing the pipe connection part 100 according to this embodiment will be described in detail with reference to FIG.

[0041] In manufacturing the pipe connection part 100 according to this embodiment, first, an operator processes a round bar of duralumin using a lathe, a milling machine, or the like to produce the pipe connection part 100 having the shape shown in Figures 1 to 4 before the formation of the coating portion CT (step S101 in Figure 6). In particular, in producing the male thread portion 20 of the pipe connection part 100, it is preferable to form a burr-free thread portion using a thread cutting tip with a flattening edge as described above.

[0042] Next, an operator cleans, degreases, and dries the pipe connection part 100 produced in step S101 before the formation of the coating portion CT (step S102 in FIG. 6). If cutting oil, rust-preventive oil, or the like remains on the surface of the pipe connection part 100, it may cause poor adhesion of the coating portion CT in a later process. If a process of providing an electroless nickel plating film on the surface of the pipe connection part 100 is added, it is preferable to perform this process immediately after step S102.

[0043] Next, the worker mounts the cleaned, degreased and dried pipe connection part 100 on a coating jig (step S103 in FIG. 6). The coating jig includes, for example, a member fixing part that can rotate the pipe connection part 100 around the central axis O1, a nozzle that applies a coating liquid to a predetermined axial position of the pipe connection part 100, and a pump device that supplies the coating liquid to the nozzle.

[0044] In addition, in parallel with the preparation, cleaning, etc. of the pipe connection part 100 before forming the coating part CT and mounting it on the application jig, the application liquid is prepared (step S104 in FIG. 6). In this embodiment, the application liquid is "Eight Seal AC-505" manufactured by Taihei Kasei Co., Ltd. The "Eight Seal AC-505" is a sealant containing 20 to 30% by weight of fluororesin (CAS number: 9002-84-0) and a solvent. The solvent used is ethyl acetate, methanol, ethanol, xylene, etc. The "Eight Seal AC-505" main agent is mixed with 100% curing agent (weight ratio) and then thoroughly stirred. The stirred application liquid is then filled into the pump device. Note that the application liquid may be other sealants having sealing properties and friction reduction performance other than the above-mentioned "Eight Seal AC-505".

[0045] Next, while rotating the pipe connection part 100 before forming the coated portion CT attached to the member fixing part of the application jig in step S103 around the central axis O1, the operator operates the pump device to apply the application liquid from the nozzle to a predetermined axial position on the male thread portion 20 (step S105 in FIG. 6). The predetermined axial position is, for example, an axial position where the tip end of the coated portion CT is within one revolution of the thread from the chamfered corner portion 22 toward the base end, and an axial position where the base end of the coated portion CT is a distance of one third or less of the thread length L from the base end of the male thread portion 20. It is more preferable that the base end of the coated portion CT is an axial position where the distance is one quarter or less of the thread length L from the base end of the male thread portion 20. It is most preferable that the base end of the coated portion CT is an axial position where the distance is one revolution of the thread from the base end of the male thread portion 20 toward the tip end. In addition, the application of the coating liquid to a predetermined axial position may be achieved by moving the axial position of a nozzle that sprays the coating liquid onto the outer surface of the male threaded portion 20 of the piping connection part 100, or by further moving the piping connection part 100 rotating around the central axis O1 in a direction along the central axis O1.

[0046] Next, the worker removes the pipe connection part 100 with the coating liquid applied to the outer surface of the male threaded part 20 from the member fixing part of the coating jig, and allows it to dry naturally for about 2 to 3 hours (step S106 in FIG. 6). By allowing the coating liquid to dry naturally in this way and volatilizing the solvent, it is possible to prevent the solvent from becoming bubbles due to heat during the baking process described below from bursting, resulting in the formation of small holes in the coating part CT. Furthermore, instead of the above-mentioned natural drying, forced drying at around 60° C. for about 30 minutes may be performed after natural drying for about 30 minutes.

[0047] Next, the worker performs a heat treatment (baking process) for 30 minutes on the pipe connection part 100 whose outer surface has been dried in a furnace whose temperature is kept between 130° C. and 160° C. (step S107 in FIG. 6). The furnace temperature is most preferably about 150° C., for example. This baking process can improve the adhesion between the coating part CT and the male thread part 20 of the pipe connection part 100. More specifically, the adhesion can be improved to such an extent that the coating part CT is not peeled off even when scratched or rubbed by a fingernail or the like. Therefore, it is possible to effectively prevent a part of the coating part CT from peeling off and getting into the pipe, or prevent the liquid coating liquid before hardening from dripping into the pipe and contaminating the inside of the pipe.

[0048] In the present embodiment, an example has been described in which each process is performed manually by an operator, but the present invention is not limited to this embodiment, and each process may be configured to be performed automatically by a production machine.

[0049] As described above, the present embodiment is a pipe connection part 100 for connecting a pipe for supplying a lubricant or a liquid agent other than a lubricant, and is configured to have a male thread portion 20 for fixing another pipe connection part on the outer surface of the main body 10, and / or a female thread portion 12 for fixing another pipe connection part on the inner surface of the main body 10, and is configured to be formed of duralumin or a lead-free free-cutting aluminum alloy. By adopting such a configuration, the pipe connection part 100 uses duralumin or a lead-free free-cutting aluminum alloy as a material, so that the density is about one-third of that of brass that has been used conventionally, and the shear strength is about 1.25 to 1.3 times that of brass, thereby making it possible to suppress the manufacturing cost by reducing the size and weight. In addition, the machinability is approximately the same as that of brass that has been used conventionally. Therefore, since dimensional accuracy can be ensured by ensuring machinability, a pipe connection part 100 with high dimensional accuracy suitable for small diameter pipes used in lubrication systems can be formed. Furthermore, since the pipe connection part 100 is made of lead-free duralumin or a lead-free free-cutting aluminum alloy, the burden on the environment can be reduced.

[0050] In this embodiment, the main body 10 has an external thread 20 for fixing another pipe connection part on its outer surface, and the external thread 20 has a coating part CT covered with a sealant containing a fluororesin. By adopting such a configuration, it is possible to effectively suppress the occurrence of galling, which may occur due to an increase in friction between the threads when duralumin or a lead-free free-cutting aluminum alloy is used as the material for the pipe connection part 100.

[0051] In this embodiment, the male thread portion 20 has a corner 22 at its tip end chamfered, and the tip end of the coating portion CT is configured to be located axially within one revolution of the thread toward the base end from the chamfered corner 22. By adopting such a configuration, a sealant containing a fluororesin can be applied up to the vicinity of the tip of the male thread portion 20, improving the sealing performance with the female thread portion of another piping connection part and effectively reducing frictional force.

[0052] In this embodiment, a coating is formed by electroless nickel plating on the surface of the main body 10. By adopting such a configuration, even when the pipe connection part 100 is used for an application other than a lubrication system for industrial machinery, for example, where the pipe connection part 100 is exposed to water, the surface of the pipe connection part 100 made of duralumin or lead-free free-cutting aluminum can be effectively prevented from corroding due to contact with water.

[0053] Moreover, the present embodiment is a manufacturing method for a pipe connection part for manufacturing the pipe connection part 100, which is configured to include preparing a coating liquid containing a fluororesin and a solvent, applying the coating liquid to a predetermined axial position of the male thread portion 20, drying the applied coating liquid, and baking the dried coating liquid. By adopting such a configuration, it is possible to effectively prevent a part of the coating portion CT from peeling off and getting into the pipe, or prevent the liquid coating liquid before hardening from dripping into the pipe and contaminating the inside of the pipe.

[0054] In this embodiment, the baking process is configured to include a heat treatment for 30 minutes in a furnace with an internal temperature of 130° C. to 160° C. By adopting such a configuration, the adhesion of the coating portion CT to the outer surface of the male thread portion 20 is improved, so that the risk of contaminating the inside of the pipe can be more effectively suppressed.

[0055] Next, a pipe connection part 200 according to a second embodiment of the present disclosure will be described with reference to Figures 7 to 9. Note that the materials used in the manufacture of the pipe connection part 200, and the relationships between the X, Y, and Z axes and the up-down, front-rear, and width directions are the same as those in the first embodiment, and therefore further description will be omitted here. In this embodiment, the central axis O1 of the male threaded part 110 and the main body part 120 extends in a direction along the X-axis.

[0056] As shown in Fig. 7 and Fig. 8, the pipe connection part 200 according to this embodiment includes a main body 120 having an outer diameter of a substantially regular hexagon when viewed from the right side, and a male threaded part 110 provided at the rear end side of the main body 120 for fixing another pipe connection part (for example, the pipe connection part 100 of the first embodiment). As shown in Fig. 7, a through hole 130 penetrates the main body 120 and the male threaded part 110 along the central axis O1, and the corners 134, 132 at the front end and the rear end are both C-chamfered. The pipe connection part 200 is also called a compression bushing, and as shown in the usage example shown in Fig. 9, the main body 120 having a regular hexagonal cross-sectional shape of the pipe connection part 200 is rotated in the direction of the arrow (clockwise when viewed from above in Fig. 9) to thread the male threaded part 110 into the female threaded part 12 of the pipe connection part 100. As a result, the tip of the male thread portion 110 of the pipe connection part 200 presses the compression sleeve (see reference numeral 30 in FIG. 9 ). Then, the pressed compression sleeve 30 fixes the pipe 40 passing through the pipe connection part 200 in the fitting tubular portion 14 of the pipe connection part 100.

[0057] 9, the male thread portion 20 of the pipe connection part 100 is threadedly engaged with, for example, a lubricating point of an industrial machine or the like to which a lubricant is supplied, a lubricant discharge portion in a lubrication device, a female thread portion 312 provided on a pipe connection part 400 (coupling) according to a fourth embodiment described below, a tapered female thread portion of another elbow adapter, a distributor that branches the flow path of a lubricant, etc. In this way, the pipe connection parts 100, 200 function as a joint, and can connect the pipe 40 to a lubricating point of an industrial machine or the like or to another pipe to form a flow path of a lubrication system.

[0058] In this embodiment, the male thread portion 110 is a parallel thread, and the nominal thread is M8. In this embodiment, a wax coating is applied to the entire surface of the pipe connection part 200 including the male thread portion 110. For this wax coating, the following process can be adopted, for example. First, the pipe connection part 200 before coating is immersed in a sieve in a liquid agent tank containing a liquid agent in which a water-soluble rust inhibitor is diluted with water for 5 to 10 seconds, and after being pulled out of the liquid agent tank, it is left in the sieve for about 3 minutes to remove oil. Then, it is centrifuged for about 3 minutes to remove the oil. By this process, the rust inhibitor adheres to the surface of the pipe connection part 200 as a coating, and when it is removed from the centrifuge, it becomes in a state where it does not feel sticky. In this way, by adhering a water-soluble rust inhibitor as a coating to at least the surface of the male thread portion 110, the frictional force when the male thread portion 110 made of duralumin is screwed into another female thread portion made of duralumin or a lead-free free-cutting aluminum alloy can be reduced, and the generation of cutting chips can be effectively suppressed.

[0059] When an electroless nickel plating film is to be provided on the surface of the pipe connection part 200, it is preferable to provide this in a step prior to the step of applying the wax coating.

[0060] Next, a pipe connection part 300 according to a third embodiment of the present disclosure will be described with reference to Figures 10 to 11. Note that the material used in the manufacture of the pipe connection part 300, the specifications and formation method of the coating part CT provided on the male thread part 220, and the relationship between the XYZ axes and the up-down direction, the front-rear direction, and the width direction are the same as those of the first embodiment, so further description will be omitted here. In this embodiment, the central axis O1 of the male thread part 220 and the main body part 210 extends in a direction along the X-axis.

[0061] As shown in Fig. 10 and Fig. 11, the pipe connection part 300 according to this embodiment includes a main body 210 having an outer diameter of a substantially regular hexagon when viewed from the right side, and a male screw portion 220 provided at the rear end of the main body 210 for fixing another pipe connection part. A female screw portion 212 is formed on the inner surface of the main body 210. In addition, a fitting cylindrical portion 214 into which the pipe 40 is fitted and fixed is provided at an axial position that is a connection point between the main body 210 and the male screw portion 220, similar to the pipe connection part 100. In addition, as shown in Fig. 10, a through hole 224 is provided at the rear end of the fitting cylindrical portion 214, which penetrates the pipe connection part 300 along the central axis O1. In this embodiment, the female screw portion 212 is a parallel screw, and the nominal size of the screw portion is M8.

[0062] The pipe connection part 300 is also called a straight adapter. That is, by disposing the pipe connection part 300, the flow path of the lubricant can be extended in the direction of the central axis O1 of the male thread part 220 provided in parallel with the pipe 40 attached to the female thread part 212. As in the engagement between the pipe connection part 100 and the pipe connection part 200 shown in FIG. 9, the main body part 120 having a regular hexagonal cross-sectional shape of the pipe connection part 200 is rotated to threadably engage the male thread part 110 with the female thread part 212 of the pipe connection part 300 of this embodiment. As a result, the tip part of the male thread part 110 of the pipe connection part 200 presses the compression sleeve 30 similar to that shown in FIG. 9. Then, the pipe connection part 200 can fix the pipe 40 penetrating the pipe connection part 200 through the compression sleeve 30 in the fitting tubular part 214 of the pipe connection part 300.

[0063] In this embodiment, the male thread portion 220 is a tapered thread that narrows toward the tip (rear, in the negative X direction). The nominal diameter of the male thread portion 220 is R1 / 8, as defined by the pipe tapered thread standard (JIS B 0203:1999). By making the male thread portion 220 a tapered thread, it is possible to improve the liquid-tightness of the joint with the female thread portion.

[0064] A coated portion CT similar to that of the first embodiment is provided on the outer surface of the male thread portion 220. As in the first embodiment, the tip end of the coated portion CT is located axially within one revolution of the thread from the chamfered corner portion 222 toward the base end. That is, the axial distance L1 in FIG. 10 is equal to or less than the pitch P of the male thread portion 220. In addition, the axial distance L2 from the base end of the male thread portion 220 to the base end of the coated portion CT is equal to or less than one-third of the thread length L.

[0065] After the pipe connection parts 200, 300 are assembled as described above, the male thread portion 220 of the pipe connection part 300 is threadedly engaged with, for example, a lubricant-supplied location of an industrial machine or the like, a lubricant discharge portion of a lubrication device, a female thread portion 312 provided on a pipe connection part 400 (coupling) according to a fourth embodiment described below, a tapered female thread portion of another elbow adapter, a distributor that branches the flow path of a lubricant, etc. In this way, the pipe connection parts 200, 300 function as a joint, and can connect the pipe 40 to a lubricant location of an industrial machine or the like or to another pipe to form a flow path of a lubrication system.

[0066] Next, a pipe connection part 400 according to a fourth embodiment of the present disclosure will be described with reference to Figures 12 to 13. Note that the materials used in the manufacture of the pipe connection part 400 and the relationships between the X, Y, and Z axes and the up-down, front-rear, and width directions are the same as those in the first embodiment, and therefore further description will be omitted here. In this embodiment, the central axis O1 of the female threaded portion 312 and the main body portion 310 extends in a direction along the X-axis.

[0067] As shown in Fig. 12 and Fig. 13, the pipe connection part 400 according to this embodiment includes a main body 310 having a substantially circular outer shape in a right side view, and a female thread portion 312 provided at the front end and the rear end of the main body 310 for fixing other pipe connection parts. As shown in Fig. 12, a through hole 324 penetrates the main body 310 along the central axis O1. The pipe connection part 400 is also called a coupling. By connecting the male thread portion 20 shown in Fig. 9 to the female thread portion 312 of the pipe connection part 400 shown in Fig. 12, the pipes 40 can be connected to each other to form a flow path of a lubrication system.

[0068] In this embodiment, the female thread portion 312 is a tapered thread that reduces in diameter from both ends in the direction of the central axis O1 toward the center position in the axial direction. The female thread portion 312 allows for threaded engagement with a male thread portion of another piping connection part from both sides in the direction of the central axis O1. The nominal diameter of the female thread portion 312 is Rc1 / 8, as defined in the pipe taper thread standard (JIS B 0203:1999). By making the female thread portion 312 a tapered thread, it is possible to improve the liquid-tightness of the joint with the male thread portion.

[0069] In this embodiment, as shown in FIG. 12, the outer peripheral surface of the main body 310 except for both ends in the central axis O1 direction is provided with D-cuts 320 at four circumferential locations as viewed in the central axis O1 direction. As shown in FIG. 13, the D-cuts are planar cuts that are provided at four circumferential locations at equal intervals, each of which forms a substantially D-shape when viewed in the central axis O1 direction. By providing the D-cuts 320 at four circumferential locations, the processing time for the outer peripheral portion of duralumin, which is usually only available in the form of a round bar, can be reduced (compared to processing into a regular hexagon), while making it easier to fix the outer peripheral portion of the pipe connection part 400 with a wrench when connecting the pipe connection part 400 to another pipe connection part. In addition, by leaving uncut regions (corner post portions 315, see FIG. 13) on both circumferential sides of the D-cuts 320, the torsional strength at the axial position where the D-cuts 320 are provided can be ensured. Furthermore, by not providing the D-cut 320 at either end in the direction of the central axis O1, a decrease in strength of the pipe connection part 400 caused by providing the D-cut 320 can be suppressed.

[0070] As described above, in this embodiment, the inner surface of the cylindrical main body 310 is provided with the female threaded portion 312 that can be threadedly engaged with the male threaded portion of another pipe connection part from both sides in the axial direction, and the outer peripheral surface of the main body 310, except for both ends in the axial direction, is configured to have D cuts 320 at four locations in the circumferential direction as viewed in the axial direction. By adopting such a configuration, it is possible to reduce the processing time for the outer peripheral portion of duralumin, which is only available in the form of a round bar, while making it easier to fix the outer peripheral portion of the pipe connection part 400 with a wrench. In addition, by not providing the D cuts 320 at both ends in the direction of the central axis O1, it is possible to prevent a decrease in the strength of the pipe connection part 400 caused by providing the D cuts 320.

[0071] Although the present disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present invention. For example, the functions included in each component can be rearranged so as not to cause logical inconsistency, and multiple components can be combined into one or divided. It should be understood that these are also included in the scope of the present invention.

[0072] For example, although the present disclosure has been limited to the pipe connection parts 100 to 400 according to the first to fourth embodiments, the present disclosure is not limited to these aspects. Other aspects may be adopted in which the pipe connection parts are made of duralumin or a lead-free free-cutting aluminum alloy and have male and / or female threads for fixing other pipe connection parts. [Industrial Applicability]

[0073] The present disclosure can be employed as pipe connection parts 100 to 400 for connecting pipes. [Explanation of symbols]

[0074] 10 Main body 11 Cylindrical part 12 Female thread 14 Fitting cylinder part 20 Male thread 22 Corner 24 Liquid flow path 30 Compression Sleeve 40 Piping 100,200,300,400 Piping connection parts 110 Male thread 112 Corner 120 Main body 130 Through hole 132,134 Corner 210 Main body 212 Female thread 214 Fitting cylinder part 220 Male thread 222 Corner 224 Through hole 310 Main body 312 Female thread 315 Corner pillar section 320 D cut 324 Through hole CT Coating Department L Thread length L1,L2 Axial distance O1,O2 Center axis Pitch

Claims

1. A piping connection part for connecting a piping for supplying a lubricant or a liquid other than a lubricant, A male thread portion for fixing other piping connection parts is provided on the outer surface of the main body portion, and / or a female thread portion for fixing other piping connection parts is provided on the inner surface of the main body portion, Pipe connection parts made of duralumin or lead-free, free-cutting aluminum alloy.

2. A male thread portion for fixing other piping connection parts is provided on the outer surface of the main body, The pipe connection part according to claim 1 , wherein the male thread portion has a coating portion covered with a sealant containing a fluororesin.

3. 3. The piping connection part according to claim 2, wherein a corner of a tip portion of the male thread portion is chamfered, and a tip end portion of the coating portion is located axially within one revolution of the thread from the chamfered corner toward the base end.

4. The female thread portion is provided on an inner surface of the cylindrical main body portion, and the female thread portion is capable of threadably engaging with a male thread portion of another pipe connection part from both sides in the axial direction, The pipe connection component according to claim 1 , wherein an outer peripheral surface of the main body, excluding both axial ends, is provided with D-shaped cuts at four positions in the circumferential direction when viewed in the axial direction.

5. 3. The pipe connection part according to claim 1, wherein a coating is formed on the surface of said main body by electroless nickel plating.

6. A method for manufacturing a pipe connection part according to claim 2 or 3, comprising the steps of: preparing a coating liquid containing a fluororesin and a solvent; applying the coating liquid to a predetermined axial position of the male thread portion; drying the applied coating liquid; baking the dried coating liquid; A method for manufacturing a piping connection part, comprising:

7. The method for manufacturing a pipe connection component according to claim 6, wherein the baking treatment includes a heat treatment for 30 minutes in a furnace having an internal temperature of 130°C or more and 160°C or less.

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