KR920008555B1 - Casting body formed with a fluid passage therein and a manufacturing method thereof - Google Patents

Abstract

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Description

Casting body formed with a fluid passage therein and a manufacturing method thereof

1 is a longitudinal sectional view of an oil pump using a pump main body (casting body) according to one embodiment of the present invention.

2 is a perspective view showing a core having a two-piece structure integrated by a pipe;

3 is an equivalent of FIG. 1 showing a conventional oil pump.

4 and 5 are cross-sectional views showing the main parts of those in FIG.

6 is a perspective view showing a conventional core shape.

* Explanation of symbols for the main parts of the drawings

1: Cam ring 2: Rotor

3: pump body 4: input shaft

6: side plate 7: pressure plate

10: spring 13: suction passage

14: vane 15: discharge chamber

16 flow control valve 22 special plug

24: metal pipe 25a, 25b: core

The present invention relates to a cast body in which a fluid passage is formed therein, in particular, a cast body in which the direction of the passage is complicated and a manufacturing method thereof.

As a cast body in which the fluid passage formed inside is bent in several directions, for example, the pump main body of an oil pump is shown, as shown to FIG. 3 thru | or FIG.

The oil pump accommodates the cam ring 1 and the rotor 2 which rotates in the cam ring in the pump body 3 made of a cast body, and at the tip of the input shaft 4 inserted into the pump body 3. One rotor 2 is connected to transmit the rotation of the input shaft 4 to the rotor 2.

The rotor 2 and the cam ring 1 are in a cavity 5 opening at one end side of the pump body 3, and the side plate 6 disposed at the corner of the cavity and the pressure plate disposed at the opening shaft ( 7), the pressure plate 7, the cam ring 1 and the side plate 6 are positioned in the rotational direction with respect to the pump body 3 by pins 8, and the cavity 5 It is always pressed against the cavity wall 11 shaft by the spring 10 provided between the inner surface of the cover 9 which closes the opening part of the cover, and the pressure plate 7.

The pump body 3 is provided with a suction port 12 and a suction passage 13 connected to an oil tank (not shown).

When the rotor 2 sandwiched between the side plate 6 and the pressure plate 7 rotates in the cam ring 1, each vane 14 slides to the inner surface of the cam ring 1, The volume in each pump chamber formed between two vanes 14 increases and decreases.

The oil sucked into the pump room from the above and the suction tract 13 by the increase and decrease of the volume is discharged between the pressure plate 7 and the cover 9 through the discharge port 7a of the pressure plate 7 ( 15, discharged from the discharge chamber 15 to the flow rate regulating valve 16 via the passage 15a, and flow rate controlled by the flow rate regulating valve 16 to be sent to the hydraulic equipment.

In addition, the pump main body 3 has a bearing 17 which supports the input shaft 4 freely with respect to the pump main body, and an oil seal 18 which prevents leakage to the outside. Return passages 19 for lubrication using the circumference are provided so that both ends thereof communicate with the space 20 around the input shaft and the low pressure portion of the suction port 12 shaft.

In this way, since the fluid passages for various purposes are formed vertically and horizontally in the pump main body 3, it is difficult to form the respective flow passages linearly between the points to be connected, so that the suction passages 13 and the like 3 It is formed as a curved flow path that changes dimensionally.

As described above, a three-dimensional curved flow path that cannot be manufactured with a shell mold core of one body is conventionally formed as follows.

That is, the suction passage 13 inserts a single shell mold core (hereinafter referred to as shell core) having a curved outer surface at the time of casting of the pump body into a predetermined portion in the mold and injects molten metal into the curved portion of the passage. After forming (21a), drill the holes (21b) (21f) by drilling toward one end of the curved portion (21a) formed by the shell core from the outside of the casting body, that is, the bending point of the suction passage, from the outside of the cast body A red bend passage is formed, and the opening by the drill is closed by the special plug 22.

As another method, two shell cores 23a and 23b of different diameters having an arcuate curved outer surface are integrally connected as shown in Fig. 6, integrated into a predetermined portion in the mold, and then poured. Molding

However, in the former case of forming the suction passage 13 that changes three-dimensionally by the complex machining of casting and machining, between the hole 21a by the shell core and the hole 21b by the drill Not only is it difficult to center, it is difficult to prevent the end portion 21c from being formed on the inner surface of the suction passage, and a bag hole 21d is formed inside the plug 22, and machining is likewise performed. Since the two holes 21b and 21f cross each other at an angle perpendicular to each other, the backhaul 21e is formed, which adversely affects the flow of oil and causes noise, and moreover, the pump is machined. Since openings are formed in the main body, there is a difficulty in deteriorating oil tightness.

In the latter case of forming the suction passage 13 at the time of casting by connecting two shell cores 23a and 23b having different diameters to each other, an end portion of the shell coil connection portion is formed on the inner surface of the suction passage. The problem remains that since the electrons occur like electrons, they adversely affect the flow of oil.

Accordingly, it is an object of the present invention to provide a casting in which no end or hole exists in a complicated curved fluid passage. Another object is to provide a method for producing a cast article having the above-described configuration.

Hereinafter, the present invention will be described by way of examples.

1 is a view showing an oil pump using a cast body, i.e., a pump body according to an embodiment of the present invention, and is the same as the conventional oil pump shown in FIG. 3 except for the shape of the suction passage 13, The same parts are denoted by the same reference numerals and the description thereof is omitted.

In this embodiment, the suction passage 13 of the oil pump is formed by the metallic pipe 24 and the pipe 24 which form part of the flow path surface coinciding with the inner surface of the suction passage 13 buried at the time of casting. Molding is performed by two connected cores having the same diameter.

This will be described in detail according to the manufacturing procedure. First, one end of each of the two cores 25a and 25b having the outer surface curved in the shape of an arc as shown in FIG. 2 has the same diameter, and these ends are attached to the metallic pipe 24. It is connected to each other to form a core having a two-dimensionally changed two-dimensional structure.

Next, the integrated core is inserted into a predetermined portion in the mold, and the water is poured to fill the pipe 24 described above.

Thereafter, a chemical solution is introduced into the cast suction passage 13 to dissolve and extract the residue.

The pipe 24 remains in the suction passage 13 as part of the passage.

The oil pump having the pump body 3 manufactured by the manufacturing method as described above has no end or hole in the suction passage 13 which hinders the flow of oil as in the prior art. There is a number.

In addition, as the number of holes and special plugs due to machining are reduced, the number of factors causing the leakage of machining work and oil can be reduced, and the manufacturing cost can be reduced so that the number of parts can be reduced.

Incidentally, in the above embodiment, the core has a two-piece structure. However, it is needless to say that a multi-body structure such as three or four pieces can be easily obtained by using a plurality of pipes 24.

In addition, although the above embodiment shows that the present invention is used in an oil pump, it is obvious that the present invention can be applied to other castings that require a complicated three-dimensional curved flow path.

Claims (3)

In a cast body having a fluid passage therein, the pipe 24 is buried in the fluid passage, and the inner surface of the pipe and the portions located on both sides of the pipe of the fluid passage have the same inner surface with no step. A cast body formed with a fluid passage therein. 2. The casting body according to claim 1, wherein the cast body is provided with a pump cartridge having a rotor (2) connected to the cam ring (1) and the input shaft (4) and rotating in the cam ring, and bent to avoid the pump cartridge (ridge), the input shaft, and the like. A casting body having a fluid passage therein, characterized in that the fluid passage is a pump body (3) formed therein. The plurality of cores are connected to each other by a pipe to form a core having a multi-body structure, and the integrated core is inserted into a predetermined portion in the mold and poured to fill a fraud pipe, and the core residue is extracted. Method for producing a cast body formed with a fluid passage.

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