JP4757015B2 - Manufacturing method of L-shaped joint made of synthetic resin - Google Patents

Description

  In the present invention, the first connecting pipe part that is directed to one side from the cylindrical part and the second connecting pipe part that is directed downward from the cylindrical part are formed so as to be substantially orthogonal to each other, and the second connecting pipe part is formed from one side end of the first connecting pipe part. With regard to the L-shaped joint in which the flow path is formed toward the lower end of the connecting pipe portion, the L-shaped joint is often used for a fuel pipe of a fuel injection device that supplies fuel toward the internal combustion engine.

Such an L-shaped joint is injection-molded with a synthetic resin material such as PA66 in view of reduction in manufacturing cost, weight reduction of the joint, and corrosion resistance.
Here, a conventional L-shaped joint will be described with reference to FIGS.
FIG. 4 is a side view of the L-shaped joint. FIG. 5 is a top plan view of FIG.
30a is a cylindrical part formed in a cylindrical shape that forms the base of the L-shaped joint 30, and a first connecting pipe part 30c is formed to project horizontally from the outer side 30b of the cylindrical part 30a toward one side A.
Further, a guide tube portion 30e is formed to protrude downward B from the lower end 30d of the cylindrical portion 30a, and a second connection tube portion 30f is formed further downward from the guide tube portion 30e. The diameter of the second connecting pipe portion 30f is smaller than the diameter of the guide pipe portion 30e, thereby forming a locking step portion 30g facing downward at the lower end of the guide pipe portion 30e.
Reference numeral 30h denotes an attachment flange extending from the outer side 30b of the cylindrical portion 30a toward the other side B. The attachment flange 30h is provided with an attachment hole 30j penetrating in the vertical direction.
Further, a flow path 30n is bored from one side end 30k of the first connection pipe part 30c toward the lower end 30m of the second connection pipe part 30f.

The L-shaped joint 30 is formed in, for example, the throttle body 31, and the first flow path 32 opened to the end surface 31a and the fuel pipe 33 inserted and connected to the first connection pipe portion 30c are flow paths in a perpendicular direction. Connecting.
Specifically, as shown by the one-dot chain line in FIG. 4, the guide pipe part 30e of the L-shaped joint 30 is inserted into the guide hole 34 that is continuous with the first flow path 32 and opens in the end face 31a, and the second connection pipe part. 30f is inserted into the first flow path 32, and the seal ring 35 is further arranged in a contracted manner so as to face the engaging stepped portion 30g of the guide tube portion 30e, the outer periphery of the second connection tube portion 30f, and the guide hole 34. Thus, the attachment flange 30h is screwed and fixed to the throttle body 31 with the screw 36 through the attachment hole 30j of the attachment flange 30h disposed in contact with the end surface 31a of the throttle body 31.
As described above, the first flow path 32 formed in the throttle body 31 is connected to the fuel pipe 33 through the flow path 30 n of the L-shaped joint 30.

The L-shaped joint 30 is formed by injection molding using a synthetic resin material.
Specifically, a first manufacturing method by injection molding of the L-shaped joint will be described with reference to FIG.
Reference numeral 40 denotes a movable mold that can move upward D. The first contact surface 40a (the first contact surface 40a is shown in the figure) along the longitudinal axis S-S of the first connecting pipe portion 30c of the L-shaped joint 30. 5 is formed on the first contact surface 40a, the upper portion 30ca above the longitudinal axis SS of the first connecting pipe portion 30c, and the upper portion of the cylindrical portion 30a. A concave portion corresponding to 30 a 1 is formed to form the first cavitating 41.
That is, the first cavitating 41 opens to the first contact surface 40a.
Reference numeral 42 denotes a fixed mold, which includes a second contact surface 42 a that contacts the first contact surface 40 a of the movable mold 40.
And on this 2nd contact surface 42a, the lower side part 30cb below the longitudinal axis line SS of the 1st connection pipe part 30c, the lower side part 30a2 of the cylinder part 30a, the attachment collar part 30h, a guide pipe part A concave portion corresponding to 30e and the second connecting pipe portion 30f is formed to form the second cavitating 43, and the second cavitating 43 opens to the second abutting surface 42a. Note that the first and second contact surfaces 40a and 42a in the above are the split surfaces of the mold.

The L-shaped joint 30 is formed by the following.
That is, the first abutment surface 40a of the movable mold 40 is brought into contact with the second abutment surface 42a of the fixed mold 42 in the vertical directions D and B, so that the first cavitating 41 and the second cavitating 43 can reduce L. A closed cavity corresponding to the mold joint 30 is formed, and a molten synthetic resin material is injected into the cavity, and after the synthetic resin material is solidified, the mold is opened to form the L-shaped joint 30. In addition, the flow path 30n and the mounting hole 30j are cast and formed by a casting pin that is pulled out to one side A and downward B, and the molded L-shaped joint 30 is taken out from the mold by the extrusion pin. However, this core pin and extrusion pin have been omitted for ease of explanation.

Next, a second manufacturing method by injection molding of the L-shaped joint 30 will be described with reference to FIG.
Reference numeral 50 denotes a movable mold that can move to one side, and a first abutment surface 50a (longitudinal axis TT in the vertical direction of the cylinder part 30a, the guide pipe part 30e, and the second connection pipe part 30f ( The first abutting surface 50a is formed in the vertical direction in FIG. 6, and the first abutting surface 50a has one side portion 30a3 of the cylindrical portion 30a on one side from the longitudinal axis TT. A first cavity 51 is formed by recessing one side 30e1 of the guide tube 30e, one side 30f1 of the second connection tube 30f, and a recess corresponding to the first connection tube 30.
Reference numeral 52 denotes a fixed mold, which includes a second contact surface 52 a that contacts the first contact surface 50 a of the movable mold 50.
And, on the second contact surface 52a, the other side portion 30a4 of the cylindrical portion 30a, the other side portion 30e2 of the guide tube portion 30e, and the second connecting tube portion 30f on the other side from the longitudinal axis TT. The other side portion 30f2 and a concave portion corresponding to the attachment flange portion 30h are formed to form the second cavitating 53.

  Then, the first abutment surface 50a of the movable mold 50 is brought into contact with the second abutment surface 52a of the fixed mold 52 in the left and right directions C and A, whereby the L A closed cavity corresponding to the mold joint 30 is formed, and the molten synthetic resin material is injected into the cavity similar to the above, and the L-shaped joint 30 is injection molded.

According to the first manufacturing method of the conventional L-shaped joint, the burr along the longitudinal axis S-S is generated on the outer periphery of the first connecting pipe portion 30. It occurs on the parting surfaces of the contact surfaces 40a and 42a.
According to this, when the fuel pipe 33 is inserted and connected to the outer periphery of the first connecting pipe portion 30, there is a possibility that fluid leakage may occur from the burr portion. (Burr generated in the above is indicated by a horizontal dotted line in FIG. 5.)
Thus, after injection molding of the L-shaped joint 30, it is necessary to perform such a burr removal operation and a leakage check operation after inserting and connecting the fuel pipe 33, and the manufacturing cost of the L-shaped joint 30 is effective. Cannot be reduced.
The burr removal operation requires a lot of skill.

  Further, according to the second conventional manufacturing method of the L-shaped joint, burrs are generated along the longitudinal axis TT in the vertical direction of the cylindrical portion 30a, the guide tube portion 30e, and the second connection tube portion 30f. Therefore, according to this burr, there is a possibility that the fluid in the first flow path 32 of the throttle body 31 may leak out of the throttle body 30 and has the same problem as described above. (The burr generated in the above is shown by the dotted line in the vertical direction in FIG. 6)

  The present invention has been made in view of the above problems, and particularly when the L-shaped joint is injection-molded using a synthetic resin material, the first connection pipe portion 30c and the first flow path 32 into which fuel pipes are inserted and connected are particularly provided. Provided is a method for manufacturing an L-shaped joint made of a synthetic resin, which can completely suppress the occurrence of burrs during injection molding on the outer periphery of the second connecting pipe portion 30f to be inserted and arranged, thereby achieving reduction in manufacturing cost. The purpose is to do.

In order to achieve the above object, the method for producing an L-shaped joint made of a synthetic resin according to the present invention,
A tubular portion, and a locking tube portion that projects horizontally toward one side from the outside of the tubular portion,
A first connecting pipe portion that protrudes further horizontally from one side end of the locking tube portion and has a smaller diameter than the locking tube portion;
A guide tube portion projecting downward from the lower end of the tube portion, a second connection tube portion projecting further downward from the lower end of the guide tube portion and having a smaller diameter than the guide tube portion,
A mounting flange projecting from the outside of the tube portion toward the other side;
In an L-shaped joint provided with a flow path drilled from one side end of the first connection pipe portion toward the lower end of the second connection end portion,
In the first movable mold that can move upward,
A first abutting surface is formed along the longitudinal axis XX of the locking tube portion, and one side end of the first abutting surface is upward along the one side end of the locking tube portion. A second contact surface is formed on the first contact surface including the second contact surface, and an upper portion of the locking tube portion including one side end above the longitudinal axis XX. The first cavity is formed by forming a concave portion corresponding to the upper portion of the cylindrical portion,
On the other hand, the fixed mold disposed opposite to the first movable mold includes a third contact surface that contacts the first contact surface, and a locking tube portion from one end of the third contact surface. A fourth abutting surface is formed in a downward direction along one side end, and the third abutting surface including the fourth abutting surface has a one side end below the longitudinal axis XX. Including a lower portion of the locking tube portion, a lower portion of the cylindrical portion, a guide tube portion, a second connection tube portion, and a concave portion corresponding to the attachment flange portion to form a second cavity.
Furthermore, in the second movable mold that can move to one side,
A fifth contact surface that is in contact with the second contact surface of the first movable mold and the fourth contact surface of the fixed mold is formed, and the fifth contact surface corresponds to the first connecting pipe portion. A third cavity is formed by forming a concave portion to be closed, and the first and second are formed to be closed by contacting each contact surface of the first movable mold, the fixed mold, and the second movable mold. The L-shaped joint is injection-molded with a synthetic resin material by a third cavitating.

According to the method for manufacturing an L-shaped joint made of a synthetic resin of the present invention, the first cavities, the second cavities, the second cavities, the second cavities, and the second cavities are brought into contact with each other by contacting the contact surfaces of the first movable mold, the second movable mold, and the fixed mold. A closed cavitation corresponding to an L-shaped joint is formed by three cavities, and a synthetic resin material melted into the cavities is injected to form an L-shaped joint made of synthetic resin.
And since there is no contact surface (parting surface) by the mold in the first connecting pipe part, no casting burr is generated on the outer periphery of the first connecting pipe part by the parting surface.
Therefore, the fuel pipe can be hermetically connected without any processing with respect to the first connection pipe portion.
In addition, since there is no abutment surface (parting surface) due to the mold in the guide tube portion and the second connecting tube portion, casting burrs are generated due to the dividing surface on the outer periphery of the guide tube portion and the second connecting tube portion. do not do.
Therefore, the second connection pipe portion can be hermetically connected to a flow path formed in, for example, the throttle body without any processing.
According to the above, since there is no need to remove the casting burr for the first connecting pipe part and the second connecting pipe part that are inserted and connected to the fuel pipe and the flow path in particular, the processing cost of the L-shaped joint is reduced. In addition, the airtightness confirmation work by casting burr can be abolished, the inspection cost can be reduced, and an inexpensive and highly airtight synthetic resin L-shaped joint can be provided.

Hereinafter, the manufacturing method of the synthetic resin L-shaped joint according to the present invention will be described.
An L-shaped joint 1 injection-molded with a synthetic resin material is shown in FIGS.
FIG. 1 is a side view of an L-shaped joint. FIG. 2 is a top plan view of FIG. It is.
1a is a cylindrical part such as a cylinder or a square that forms the base of the L-shaped joint 1, and a locking pipe part 1c having a circular cross section projects horizontally from an outer side 1b of the cylindrical part 1a toward one side A. Further, the first connecting pipe portion 1e having a circular cross section is formed horizontally toward the one side A from the one side end 1d of the locking pipe portion 1c.
The longitudinal axis of the first connecting tube portion is formed concentrically with the longitudinal axis XX of the locking tube portion 1c, and the diameter of the first connecting tube portion 1e is the diameter of the locking tube portion 1c. It is formed with a smaller diameter.
According to the above, the locking step portion 1f facing the one side A is formed at the one side end 1d of the locking tube portion 1c.
Further, a guide tube portion 1h is formed to protrude downward B from the lower end 1g of the cylindrical portion 1a, and a second connection tube portion 1k is formed further downward B from the lower end 1j of the guide tube portion 1h.
The guide tube portion 1h and the second connection tube portion 1k are formed concentrically, and the diameter of the second connection tube portion 1k having a circular cross section is smaller than the diameter of the guide tube portion 1h having a circular cross section. Thus, a locking step portion 1m facing downward is formed at the lower end 1j of the guide tube portion 1h.
According to the above, the locking tube portion 1c, the first connecting tube portion 1e, the guide tube portion 1h, and the second connecting tube portion 1k are formed substantially orthogonally.
In addition, 1n is an attachment hook part formed so as to protrude from the outer side 1b of the cylindrical part 1a toward the other side C, and an attachment hole 1p is drilled through the attachment hook part 1n.
In addition, a flow path 1t is bored from one side end 1r of the first connection pipe portion 1e toward the lower end 1s of the second connection pipe portion 1k.

Here, the L-shaped joint 1 having such a structure is connected to the flow path by the following.
The lower surface of the mounting flange 1n of the L-shaped joint 1 and the lower end 1g of the cylindrical portion 1a are arranged on the end surface 2a of the throttle body 2, and the guide tube portion 1h is opened in the end surface and formed in the guide hole 2b. The second connecting pipe portion 1k is inserted into the first flow path 2c connected to the guide hole 2b, and the locking step portion 1m of the guide pipe portion 1h, the outer periphery of the second connecting pipe portion 1k, and the guide hole The seal ring 3 is disposed in a reduced manner at 2b.
In this state, a screw 4 is inserted into the mounting hole 1p of the mounting flange 1n, and the L-shaped joint 1 is screwed to the throttle body 2 by this screw 4.
On the other hand, the fuel pipe 4 is inserted and connected to the outer periphery of the first connecting pipe portion 1e toward the locking step portion 1f.
Thus, the first flow path 2 c formed in the throttle body 2 is connected to the fuel pipe 4 through the flow path 1 t in the L-shaped joint 1.

And the L-shaped joint 1 which consists of the said structure is injection-molded by the synthetic resin material by the following.
This will be described with reference to FIG.
Reference numeral 5 denotes a first movable mold that can move in the upward direction D. The first abutting surface 5a in the horizontal direction along the longitudinal axis XX of the locking tube portion 1c of the L-shaped joint 1, A second abutting surface 5c is formed along one side surface 1d of the tube portion 1c from the one end 5b of the first abutting surface 5a toward the upper side D.
The first contact surface 5a including the second contact surface 5c includes one end 1d1 of the locking tube portion 1c above the longitudinal axis XX and above the longitudinal axis XX. A concave portion corresponding to the upper portion 1c1 of the locking tube portion 1c and the upper portion 1a1 of the cylindrical portion 1a is provided to form the first cavitating V1.

Reference numeral 6 denotes a fixed mold, and a third contact surface along the third contact surface 6a that contacts the first contact surface 5a of the first movable mold 5 and one side surface 1d of the locking tube portion 1c. A fourth contact surface 6c is formed from one side end 6b of 6a toward the lower side B.
The third abutting surface 6a including the fourth abutting surface 6c has one end 1d2 of the locking tube portion 1c below the longitudinal axis XX and a portion below the longitudinal axis XX. Lower portion 1c2 of the locking tube portion 1c
And the lower part 1a2 of the cylinder part 1a, the guide pipe part 1h, the 2nd connection pipe part 1k, and the recessed part equivalent to the attachment collar part 1n are recessed, and the 2nd cavitating V2 is formed.

Reference numeral 8 denotes a second movable mold that can move to one side A, and a fifth contact that contacts the second contact surface 5 c of the first movable mold 5 and the fourth contact surface 6 c of the fixed mold 6. A surface 8a is formed.
A recess corresponding to the first connecting pipe portion 1e is formed in the fifth contact surface 8a to form a third cavitating V3.

The first contact surface 5 a of the first movable mold 5 is brought into contact with the third contact surface 6 a of the fixed mold 6, the fourth contact surface 6 c of the fixed mold 6, and the first movable mold 5. The fifth contact surface 8a of the second movable mold 8 is placed in contact with the second contact surface 5c of the second contact surface 5c, thereby corresponding to the L-shaped joint 1 by the first cavitating V1, the second cavitating V2, and the third cavitating V3. The cavities are closed and formed.
Then, the molten synthetic resin material is injected into the cavitation, and after the synthetic resin material is solidified, the mold is opened and the L-shaped joint 1 is taken out.
In addition, the extrusion pin which pushes out the casting pin which forms the flow path 1t and the attachment hole 1p, and an L-shaped joint from the metal mold | die was abbreviate | omitted.

According to the L-shaped joint 1 of the present invention manufactured as described above, when injection molding is performed using a synthetic resin material, the fuel pipe 4 is inserted into the outer periphery of the first connection pipe portion 1e to which the fuel pipe 4 is inserted and connected and into the flow path 1t. Then, no casting burr is generated on the outer periphery of the second connecting pipe portion 1k in which the seal ring 3 is inserted and arranged on the outer periphery thereof.
This is because the first connecting pipe portion 1e and the second connecting pipe portion 1k do not have a contact surface (a mold breaking surface).
And according to the above, it is not necessary to perform the casting burr removal work of the first connecting pipe part 1e and the second connecting pipe part 1k after the L-shaped joint 1 is formed by injection molding, and these connections, insertions, The airtight test at the portion can be eliminated, and an L-shaped joint made of a synthetic resin that is extremely inexpensive and highly airtight can be provided.

In addition, the 1st connection pipe part is formed toward the one side A from the outer side 1b of the cylinder part 1a, and the annular ring which protrudes partially from the 1st connection pipe part is provided in the intermediate position of this 1st connection pipe part. May be.
Such an annular ring corresponds to one end 1d (in other words, a locking step 1f) shown in FIG.

The side view of the L type joint used for the manufacturing method of the L type joint made from the synthetic resin which becomes this invention. FIG. 2 is a top plan view of FIG. 1. The longitudinal cross-sectional view of the metal mold | die used in order to implement the manufacturing method of the synthetic resin L-shaped joint which becomes this invention. The side view of the conventional synthetic resin L-shaped joint. FIG. 5 is a top plan view of FIG. 4. The longitudinal cross-sectional view of the metal mold | die used in order to implement the 1st manufacturing method of the conventional synthetic resin L-shaped joint. The longitudinal cross-sectional view of the metal mold | die used in order to implement the 2nd manufacturing method of the conventional synthetic resin L-shaped joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Tube part 1c Locking pipe part 1d One side end of locking pipe part 1e 1st connection pipe part 1h Guide pipe part 1k 2nd connection pipe part 5 1st movable metal mold | die 5a 1st contact surface 5c 2nd contact Surface V1 First Cavitation 6 Fixed Mold 6a Third Abutting Surface 6c Fourth Abutting Surface V2 Second Cavitation 8 Second Movable Mold 8a Fifth Abutting Surface V3 Third Cavitation

Claims (1)

A cylindrical portion 1a, a locking tube portion 1c that protrudes horizontally from the outer side 1b of the cylindrical portion 1a toward one side A, and a horizontal surface toward one side A from one side end 1d of the locking tube portion 1c. And a first connecting pipe portion 1e having a smaller diameter than the locking pipe portion 1c,
A guide tube portion 1h that protrudes downward B from the lower end 1g of the tube portion 1a, and a second connecting tube portion 1k that protrudes further downward B from the lower end 1j of the guide tube portion 1h and has a smaller diameter than the guide tube portion 1h. When,
A mounting flange 1n protruding from the outer side 1b of the cylindrical part 1a toward the other side C;
In an L-shaped joint 1 including a flow path 1t drilled from one side end 1r of the first connection pipe portion 1e toward the lower end 1s of the second connection end portion 1k,
In the first movable mold 5 that can move in the upward direction D,
A first contact surface 5a is formed along the longitudinal axis XX of the locking tube portion 1c, and one side end 5b of the first contact surface 5a is provided at one side end of the locking tube portion 1c. A second abutting surface 5c is formed in the upward direction D along 1d, and the first abutting surface 5a including the second abutting surface has one side end 1d1 above the longitudinal axis XX. A first cavitating V1 is formed by forming a concave portion corresponding to the upper portion 1c1 of the locking tube portion 1c including the upper portion 1a1 of the cylindrical portion 1a,
On the other hand, the fixed mold 6 disposed opposite to the first movable mold 5 includes a third contact surface 6a that is in contact with the first contact surface and one side end 6b of the third contact surface 6a. A fourth contact surface 6c is formed in the downward direction B along the one side end 1d of the locking tube portion 1c from the longitudinal axis line to the third contact surface 6a including the fourth contact surface. Lower part 1c2 of locking pipe part 1c including one side end 1d2 below XX, lower part 1a2 of cylindrical part 1a, guide pipe part 1h, second connecting pipe part 1k, and mounting rod A concave portion corresponding to the portion 1n is provided to form the second cavitating V2.
Furthermore, in the second movable mold 8 that can move to one side A,
A second contact surface 5c of the first movable mold and a fifth contact surface 8a that contacts the fourth contact surface 6c of the fixed mold 6 are formed, and a first connection is formed on the fifth contact surface. A concave portion corresponding to the tube portion 1e is provided to form a third cavitating V3,
The first, second, and second closures are formed by contacting the contact surfaces 5a, 5c, 6a, 6c, and 8a of the first movable mold, the fixed mold 6, and the second movable mold 8. A method for producing an L-shaped joint made of synthetic resin, wherein the L-shaped joint is injection-molded with a synthetic resin material by three cavitations.

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