JPH0336796Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention creates almost no level difference on the inner circumferential surface of the connection point when the hose is connected.
This invention relates to a fitting that prevents fluid from stagnation.

[Prior Art] Conventionally, a joint fitting comprising a nipple portion and a sleeve is coupled to the end portion of a hose used in liquid piping systems for painting, food manufacturing, etc. for connection. This fitting is made by inserting the end of the hose into the annular space formed between the nipple and a sleeve provided concentrically outside the nipple, and then tightening the outer periphery of the sleeve. It is designed to connect the hose together. (Refer to Utility Model Application No. 62-52390, etc.).

[Problems to be solved by the invention] In these conventional fittings, the outer diameter of the nipple portion is formed to match the inner diameter of the hose to be connected, and the end face of the tip of the nipple portion is
Since the hose is connected in a state where it is exposed to the inner circumferential surface of the hose, a stepped portion is created between the inner circumferential surface of the nipple portion and the inner circumferential surface of the hose. Therefore, when a conventional hose is used for liquid transfer, when liquid transfer is stopped, the liquid adhering to the stepped portion remains as it is, creating a pool of liquid. For this reason, when painting hoses for painting piping with different colors of paint, even if the inside of the hose is cleaned, the residual paint from the stepped portions will not be completely removed.
Immediately after resuming painting, different types of paints would mix, and the same problem would occur where different types of foods would mix in the hose for liquid food piping. Further, it is troublesome and time-consuming to clean until such a liquid pool is completely removed, and a long working time is required, resulting in a disadvantage that working efficiency is reduced.

Therefore, in order to prevent such liquid pooling from occurring, the present applicant heated the hose with the nipple part of the fitting fitted inside the hose end, so that the inner diameter of the hose matched with the inner diameter of the nipple part. An assembly structure that is contracted and joined together so that they are substantially equal (Utility Model Application No. 59-137486), or has an inner diameter that is substantially equal to the inner diameter of the nipple part, and has a diameter that allows its end to be inserted into the nipple part. We have already proposed an assembly structure (Utility Model Application Publication No. 186892/1983) that uses a hose whose diameter has been expanded in advance so that
Although these assembly structures eliminate the step part at the connection point, in the former method, the inner diameter of the hose used for connection needs to be determined in advance by taking into account shrinkage due to heating empirically and computationally. At the same time, the shrinkage rate differs depending on the structure of the hose, which poses problems such as making the manufacture of the hose complicated. In addition, the latter method requires a separate step of expanding the end of the hose, which is time-consuming, and there are problems in that it is troublesome to automate the assembly.

This invention was made in order to solve the problems of the conventional technology, and it is easy to connect, has high pull-out strength and sealing performance, and after connection, the tip of the nipple part and the inner circumferential surface of the hose The purpose is to provide a joint fitting that does not create a step or gap between the fittings.

[Means for solving the problem] In order to achieve the above purpose, according to this invention,
In a joint fitting in which a hose is inserted into an annular space formed between a nipple part and a sleeve and the sleeve is crimped from the outer periphery to be fixed, the inner circumferential surface of the nipple part has a diameter approximately equal to the inner circumferential surface of the hose, The outer surface is formed into a tapered surface whose diameter gradually increases from the distal end side to the base side of the nipple having a diameter approximately equal to the inner diameter of the hose, and the inner circumferential surface and outer circumferential surface of the sleeve are the outer circumferential surface and inner circumferential surface of the nipple portion, respectively. It is characterized by being formed on a plane almost parallel to .

[Function] According to this invention, as described above, the diameter of the inner circumferential surface of the nipple portion is approximately equal to the inner circumferential surface of the hose, and the diameter of the tip of the outer circumferential surface is also formed approximately equal to the inner diameter of the hose.
Since the hose has a tapered surface whose outer diameter gradually increases from the distal end toward the base, the hose can be inserted easily along the tapered surface. Therefore, after connection, a step or gap is less likely to occur between the nipple tip and the inner peripheral surface of the hose, and liquid retention and pressure loss at the connection point are prevented. Furthermore, by making the outer peripheral surface of the nipple part a tapered surface, it can be easily inserted without first expanding the hose end using an expansion jig, and there is no need to heat it to shrink it. The efficiency of assembly work is greatly improved.

In particular, in this device, the inner circumferential surface of the sleeve is formed into a tapered surface that is approximately parallel to the outer circumferential surface of the nipple portion, and the outer circumferential surface of the sleeve is approximately parallel to the inner circumferential surface of the nipple portion (relative to the axis of the fitting). (almost parallel)
Because of this, when an assembly method is adopted in which the entire length of the sleeve is crimped, the tip of the nipple part also contributes effectively to the connection, and the sleeve inserts the hose insertion part almost uniformly over its entire length. Since the nipple is compressed, the pull-out strength and airtightness are improved compared to when only the tip end of the nipple is made into a tapered surface, and the length of the nipple can be shortened to obtain the same performance.

[Embodiment] Fig. 1 is a partial longitudinal sectional side view showing an embodiment of the joint fitting according to this invention, and Fig. 2 is a partial vertical sectional side view showing a state in which a hose is connected. The illustrated joint fitting 1 is comprised of a joint body 10 and a sleeve 2.

In FIG. 1, the joint body 10 has a nipple part 11 at one end that is inserted into a hose, and the inner diameter of the nipple part 11 is approximately equal to the inner diameter of the hose to be connected, and the outer circumferential surface 12 of the nipple part 11 is The diameter gradually increases from the distal end toward the base, and the diameter of the distal end is a tapered surface that is approximately equal to the inner circumferential surface of the hose. The other end of the joint body 10 is provided with a threaded portion 13 for connecting to other joint fittings or equipment.

The sleeve 20 is fitted concentrically to the outside of the nipple portion 11 of the joint body 10 with an annular space in between, and is screwed onto the joint body 10 at the nipple base adjacent to the spanner hook portion 14 of the joint body 10. . The inner circumferential surface 21 of this sleeve 20 is formed into a tapered surface substantially parallel to the outer circumferential surface 12 of the nipple portion 11 of the joint body 10, and is formed to become thinner toward the base side of the sleeve 20. Furthermore, a plurality of annular grooves 22 are provided on the inner circumferential surface 21 . Further, the outer circumferential surface is formed to be substantially parallel to the inner circumferential surface of the nipple portion 11.

When connecting the joint fitting 1 and the hose configured in this manner, the end portion of the hose H is inserted into the annular space between the nipple portion 11 of the joint body 10 and the sleeve 20, as shown in FIG. Insert into. At this time, since the outer circumferential surface 12 of the nipple part 11 is a tapered surface whose diameter gradually increases from the tip side to the base side, the outer diameter is equal on the tip side and the base side as in the conventional case. Compared to what is
Easy to insert. When the sleeve 20 is pressurized and tightened from the outer circumference, the diameter of the sleeve 20 is reduced and the end portion of the hose H is compressed, so that the annular groove 22 provided on the inner circumference of the sleeve 20 is formed on the outer circumference of the hose H. It is joined in a state where it is bitten into. Here, the inner circumferential surface 21 of the sleeve 20 is
is formed into a tapered surface substantially parallel to the outer peripheral surface 12 of the
In addition, since the outer peripheral surface of the sleeve 20 is parallel to the axis of the joint body 10, when the sleeve 20 is tightened continuously in the length direction, the force is applied to the hose H.
The force is applied almost uniformly over the entire length of the inserted portion of the hose H, and the entire length of the inserted portion of the hose H is clamped with approximately the same force. As a result, a structure with sufficient pull-out strength is obtained. Furthermore, the diameter of the tip of the outer circumferential surface 12 of the nipple portion 11 is formed to be approximately equal to the inner diameter of the hose H to be connected, and the outer circumferential surface tapers in diameter from there toward the nipple base side, so that the connecting portion There are virtually no steps or gaps on the inner peripheral surface.

In the present invention, the diameter of the tip of the outer circumferential surface 12 of the nipple portion 11 of the joint body 10 and the inner diameter of the hose H do not necessarily have to be exactly the same as long as they are approximately equal. This means that the pressure loss and stagnation of the fluid that occurs due to the difference in diameter does not pose a practical problem.

In the embodiment described above, the annular groove is provided only on the inner circumferential surface of the sleeve 20, but this annular groove may be provided on the outer circumferential surface 12 of the nipple portion 11. Further, it may be provided on both sides, or may not be provided on both sides, and these can be appropriately selected depending on the length, wall thickness, material, etc. of the nipple portion 11. Further, if the distal end side of the nipple portion 11 is particularly thin, deformation of the nipple portion 11 may be prevented by inserting a core metal into the joint body when crimping the sleeve 20. Further, in the embodiment, the tip of the nipple part is edge-shaped, but it may be chamfered.

[Effects of the invention] As explained above, according to the fitting of this invention, the inner circumferential surface of the nipple part is made almost equal to the inner circumferential surface of the hose, and the diameter of the outer circumferential surface is made almost equal to the inner diameter of the hose. There is no difference in level between the inner circumferential surface of the nipple portion and the inner circumferential surface of the hose after connection. This eliminates the occurrence of liquid pooling at the tip, making it an extremely convenient connection structure when exchanging and transferring two or more types of paint or food, for example, for painting or liquid food. An excellent effect is obtained in that loss is also prevented.

Furthermore, according to this invention, the outer circumferential surface of the nipple part is a tapered surface whose diameter gradually increases from the tip side to the base side, so it is easy to insert the hose into the nipple part. Since the inner and outer circumferential surfaces of the sleeve that face the outer circumferential surface of the nipple portion are substantially parallel to the outer circumferential surface and the inner circumferential surface of the nipple portion, respectively, an assembly method in which the sleeve is crimped over its entire length. When adopting this method, the entire part of the nipple part from its tip to its base contributes to the coupling, and the hose is held almost uniformly between the sleeve and the fitting part over the entire length of the fitting part, making it a good fit. It provides excellent pull-out strength and sealing properties. Therefore, in order to obtain the same performance, the length can be made shorter than when only the tip of the nipple has a tapered surface.

Note that this invention is not limited to the above embodiments, and various modifications may be made within the technical concept of this invention, such as changing the shape of the joint body or changing the method of connecting the sleeve and the joint body. It is of course possible to change.

[Brief explanation of the drawing]

FIG. 1 is a partial longitudinal sectional side view showing an embodiment of the joint fitting according to this invention, and FIG. 2 is a partial vertical sectional side view showing a state in which a hose is connected to the fitting fitting of the embodiment shown in FIG. 10: Joint body, 11: Nipple part, 12, 2
1: Tapered surface, 20: Sleeve, 22: Annular groove.

Claims (1)

[Scope of utility model registration request] In a joint fitting in which a hose is inserted into an annular space formed between a nipple part and a sleeve and the sleeve is crimped from the outer periphery to secure the sleeve, the nipple part has an inner circumferential surface that has a diameter approximately equal to that of the inner circumferential surface of the hose. The sleeve has a tapered surface whose diameter gradually increases from the distal end side to the base side, and the outer circumferential surface is approximately equal to the inner diameter of the hose. A joint fitting characterized in that it is formed on a surface substantially parallel to the inner circumferential surface.