JP2001113404A - Forming method of cast end member tube attachment part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a tube fitting part preventing casting porosity leak on a cast end member. SOLUTION: A tube fitting part fitting a tube 4 of pressurized fluid is formed on an end member 1 made of aluminum casting 1a by cutting of the casting 1A. The casting 1A is provided with a tube fitting step part 3A on a main body part 2A, a step down part 7A of a smaller diameter difference than a depth of a seal member groove 6 continuing the step art 3A at the tip side, and is formed in a shape maintaining a thin machining allowance for surface finishing on entire body. The seal member groove 6 of necessary depth from a surface of a tube fitting step 3 for mounting a seal member 5 is formed on the step part 3A, and a locking projection part 8 much lower than the tube fitting step part 3 for preventing the seal member 5 from falling off at the tip side of the step part 3 is remained during surface finishing to remove the machining allowance of the casting 1A by cutting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air leak due to a cavity when an end member for mounting a cylinder tube in a sealed state is made of aluminum casting (aluminum die-cast), such as a head cover and a rod cover of a fluid pressure cylinder. The present invention relates to a method for forming a tube mounting portion in an end member capable of suppressing (burr leakage).

[0002]

2. Description of the Related Art Conventionally, in a hydraulic cylinder, a head body and a rod cover (end member) are made of aluminum casting (aluminum die-cast), and an aluminum cylinder tube is attached to the end member to form a cylinder body. Doing is generally heavily used. In this case, as shown in FIG. 3, the end member is formed into a final shape by correcting the shape of the casting surface of the surface by cutting a cast product 21A formed by aluminum die casting. This final shape is
The main body 22 of the end member 21 is provided with a tube mounting step 23 corresponding to the inner diameter of the cylinder tube 24 to be mounted, and the step 23 is provided with a sealing member 2 such as an O-ring.
5 is provided with a seal member groove 26 for fitting the same.

[0003] In such an end member, the sealing member groove 26 cannot be formed in advance at the time of casting due to the die-cutting at the time of casting, and the tube mounting step 23 is cut after casting. It is necessary to form with. In this case, the casting surface of the casting is slightly removed for surface finishing, but the seal member groove 26 needs to be formed to a depth of at least about 1.5 mm including the casting surface to be removed. There is. However, in a cast product made of aluminum die cast, the structure is dense at a position close to the surface layer, but when a groove having a depth such as the seal member groove 26 is formed by cutting, an internal cavity appears on the surface, There is a possibility that compressed air leaks through the cavity.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and its technical problem is to basically form a tube mounting portion of a casting end member without leak of a cavity. It is to provide a method. Another technical object of the present invention is to provide a method of forming a tube mounting portion in which a cast hole is prevented from leaking out of a tube mounting portion in a cast end member and at the same time, trouble such as falling off of a seal member is eliminated. It is in.

[0005]

According to a first aspect of the present invention, there is provided a tube forming method for mounting a tube end through which a pressure fluid is introduced to an end member made of an aluminum casting. In the method of forming the portion by cutting the cast product, the end member made of the cast product is provided with a tube mounting step corresponding to the inner diameter of the tube to be mounted on the main body thereof, and the tip of the step is provided. On the side, a paragraph portion having a diameter difference smaller than the depth of the seal member groove for mounting the seal member is continuously provided, and the whole is formed in a shape with a thin allowance for surface finishing, and the casting is formed. At the time of surface finishing for removing the cutting allowance by cutting, a seal member groove is formed in the paragraph section from the surface of the tube mounting step to the depth required for mounting the seal member, Dropping than the tube attaching step portion for suppressing the drop point of the distal to the seal member is characterized in that to leave a sufficiently low engagement projection.

[0006] In the first forming method, in the cutting process of the cast product of the end member, the seal member reaches a depth necessary for mounting the seal member from the surface of the tube mounting step to the paragraph section of the cast product. Although a groove is formed, this seal member groove is not provided in the tube mounting step portion, but is provided in a paragraph portion having a smaller diameter, and the depth of the seal member groove is left at the tip side of the paragraph portion. Since this corresponds to the height of the locking projection that is sufficiently lower than the tube mounting step, the possibility that the cavity of the cast product appears on the surface of the finished shape is greatly reduced, and the compressed air passes through the cavity. Troubles such as leakage can be eliminated. Further, in the end member, although it is sufficiently lower than the tube mounting step portion on the distal end side of the seal member groove in the tube mounting portion, since the locking projection is left, the sealing member may fall off. There is no trouble.

According to a second forming method of the present invention for solving the above-mentioned problems, a tube mounting portion for mounting a tube end into which a pressure fluid is introduced is mounted on an end member made of an aluminum casting. In the method in which the end member made of the cast product is provided with a tube mounting step corresponding to the inner diameter of the tube to be mounted, a seal is provided at the tip end side of the step. A series of paragraphs reduced in diameter by the depth of the seal member groove for mounting the member, and formed into a shape with a thin allowance for surface finishing as a whole, and cutting the casting The surface finishing is performed by removing the allowance.

In the above-mentioned second forming method, the cutting process of the cast product of the end member may be performed simply by removing a margin for finishing the surface of the cast product, and the cavity of the cast product may have a finished shape. There is almost no possibility of appearing on the surface, and troubles such as leakage of compressed air through the cavity can be eliminated. However, in this case, since only the paragraph portion reduced in diameter by the depth of the seal member groove for mounting the seal member is provided continuously at the distal end side of the tube mounting step portion, the seal member may not fall off. there is a possibility. However, for example, a large allowance for the narrowing of the seal member, avoiding use in the case where the positive and negative pressure fluctuations are large in the cylinder tube, and omitting the cutting process for the surface finishing on the tip side of the mounting portion of the seal member are omitted Then, such a problem as leaving a casting surface slightly protruding at that portion or using a bonding agent for holding the seal member in a predetermined position can prevent troubles such as falling off of the seal member. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a structure of a tube mounting portion in a cast end member for explaining an embodiment of a first forming method according to the present invention. The cast end member 1 is first formed as a cast product 1A by aluminum die casting, and is formed into a final finished shape by performing a cutting process described below. This end member 1, like a head cover or a rod cover of a fluid pressure cylinder, attaches a cylinder tube 4 to which a pressure fluid is introduced to a main body 2 of the end member in a state of being sealed by a seal member 5 such as an O-ring. For forming a tube.

As shown by a chain line in FIG. 1, an end die casting 1A made of aluminum die cast has a tube mounting step 3A corresponding to the inner diameter of a tube 4 to be mounted at one end of a main body 2A. At the same time, a paragraph 7A having a diameter difference smaller than the depth of the seal member groove 6 for mounting the seal member 5 with respect to the step 3A is continuously provided on the tip side of the step 3A. Compared with the finished shape, the entire shape except for the seal member groove 6 has a shape with a thin allowance for surface finishing.

When the casting 1A is machined to finish its surface, the above-mentioned allowance is entirely removed to form the final finished shape of the main body 2, the tube mounting step 3 and the like. At the same time, a seal member groove 6 is formed in the paragraph section 7A by cutting from the surface of the tube mounting step section 3 to a depth required for mounting the seal member 5, and the tip side of the paragraph section 7A is formed. The locking projection 8 which is sufficiently lower than the tube mounting step 3 for preventing the sealing member 5 from falling off is left. Since the locking projection 8 is sufficiently lower than the tube mounting step 3, the paragraph 7A connected to the tube mounting step 3A of the casting 1A is attached to the locking projection 8. It can be as low as the height.

In practice, the above-mentioned paragraph section 7A is formed by sealing member groove 6
The depth of cutting for the formation of the seal member depends on the diameter of the cylinder tube 4 and the cross-sectional shape of the seal member 5, but can be equal to or less than half the depth of the conventional seal member groove 26.
More preferably, it is set to about 5 to 0.6 mm. The surface of the locking projection 8 can be omitted from cutting for finishing.

In the first forming method, in the cutting of the cast 1A of the end member 1, it is necessary to mount the seal member 5 from the surface of the tube mounting step 3 to the paragraph 7A of the cast 1A. A sealing member groove 6 reaching the depth is formed. The sealing member groove 6 is not provided in the tube mounting step portion 3 but is provided in a paragraph portion 7A having a smaller diameter than the tube mounting step portion 3. Is equivalent to the height of the locking projection 8 which is sufficiently lower than the tube mounting step 3 to be left on the distal end side of the paragraph 7A.
The possibility that the porosity of the casting 1A appears on the surface of the finished shape is greatly reduced, and it is possible to eliminate the trouble that the compressed air leaks through the porosity. In the end member 1, the seal member groove 6 in the tube mounting portion is provided.
Although it is sufficiently lower than the tube mounting step 3 at the tip end of the tube, since the locking projection 8 is left, troubles such as falling off of the seal member 5 under various use conditions do not occur. This has been confirmed experimentally.

FIG. 2 shows a structure of a tube mounting portion similar to FIG. 1 for explaining an embodiment of the second forming method according to the present invention. This casting end member 11 is also shown in FIG.
As in the case of the end member 1 described above, it is formed as a cast product 11A by aluminum die casting, and is formed into a final finished shape by performing a cutting process described below. This end member 11 is attached to the main body 12 of the end member 11 in the same manner as the end member 1 of FIG.
A tube mounting portion for mounting the cylinder tube 14 to which the pressure fluid is introduced is formed in a state where the cylinder tube 14 is sealed by a seal member 15 such as a ring.

As shown by a dashed line in FIG. 2, a casting 11A of the end member 11 is provided at one end of a main body 12A thereof.
A tube mounting step 13A corresponding to the inner diameter of the tube 14 to be mounted is provided, and the depth of the seal member groove when the seal member 15 is mounted on the step 13A is provided at the tip side of the step 13A. The paragraph 17A whose diameter is reduced by a corresponding dimension is continuously provided, and has a shape with a thin margin for surface finishing as a whole as compared with the final finished shape of the end member.

When the casting 11A is subjected to cutting and surface finishing, the above-mentioned allowance is entirely removed, and the main body portion 12 and the tube mounting step portion 1 having the final finished shape are formed.
No. 3 is formed, and the above-mentioned margin is also simply removed for the paragraph 17A. In this case, as in the embodiment shown in FIG. 1, no seal member groove for mounting the seal member 15 is formed in the paragraph section 17A, and the depth of the seal member groove is Since only the paragraph 17 having a diameter reduced by a dimension corresponding to the above is merely provided continuously, there is a possibility that the seal member 15 may fall off, but this fall can be suppressed by various means.

For example, when the seal member 15 is dropped, a large allowance may be used for the seal member 15, use in a case where large positive and negative pressure fluctuations occur in the cylinder tube 14 may be avoided, or a position where the seal member 15 is mounted may be reduced. Also, the cutting process for the surface finish on the tip side is omitted, and a casting surface which is slightly protruding is left in that portion.
5 can be sufficiently prevented by using a bonding agent for holding 5 in a predetermined position, or by using them alone or in combination with other various means.

As described above, in the above-described second forming method, the cutting of the cast 11A of the end member 11 may be simply performed by removing a margin for finishing the surface of the cast 11A. In addition, cutting for finishing the surface of the casting 11A can be about 0.1 mm, and there is almost no possibility that the cavity of the casting appears on the surface of the finished shape, and compressed air leaks through the cavity. Such troubles can be eliminated.

[0019]

According to the forming method of the present invention described in detail above, it is possible to form a tube mounting portion in which no casting cavity leaks in a cast end member, and furthermore, to eliminate the above-mentioned leakage of the casting cavity. Insufficient member grooves,
This can also provide a method of forming the tube mounting portion that prevents troubles such as the falling off of the seal member.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of an end member for describing an embodiment of a method of forming a tube mounting portion according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of another end member for describing another embodiment of the present invention.

FIG. 3 is a vertical sectional view of a main part of a conventional end member for explaining a conventional molding method.

[Explanation of symbols]

 1,11 End member 1A, 11A Cast product 2,2A, 12,12A Main body 3,3A, 13,13A Tube mounting step 4,14 Tube 5,15 Seal member 6 Seal member groove 7A, 17A Paragraph section 8 Stop projection 8

Claims (2)

[Claims] 1. A method of forming a tube mounting portion for mounting a tube end to which a pressure fluid is introduced to an end member made of a cast aluminum product by cutting the cast product. Is provided with a tube mounting step corresponding to the inner diameter of the tube to be mounted on the main body thereof, and a step having a diameter difference smaller than the depth of the seal member groove for mounting the seal member at the tip of the step. In order to form a shape with a thin allowance for surface finishing as a whole, and to cut the casting to remove the allowance, a tube is attached to the paragraph. The tube mounting step for forming a seal member groove reaching a depth necessary for mounting the seal member from the surface of the step part, and for preventing the seal member from falling off at the tip side of the paragraph part. Leaving a sufficiently low engagement projection than the method of forming the tube mounting portion in cast iron end member, characterized in that. 2. A method for forming a tube mounting portion for attaching a tube end to which a pressure fluid is introduced to an end member made of a cast aluminum product by cutting the cast product. In the main body, a tube mounting step corresponding to the inner diameter of the tube to be mounted is provided, and at the tip side of the step, a paragraph section reduced in diameter by the depth of the seal member groove for mounting the seal member is provided. Connected,
A casting end characterized by being formed into a shape with a thin allowance for surface finish as a whole, and cutting the casting to remove the allowance to finish the surface. A method for forming a tube mounting portion in a member.