JPS6064741A - Production of cylinder head for compressor - Google Patents

Abstract

PURPOSE:To eliminate an airtight treatment of the mounting surface of a cylinder head and to make effective use of a metallic blank material for elongation having good heat conductivity by cold forming the blank material to form a cylinder head and providing relief parts for excess metal at the points where accuracy is not required. CONSTITUTION:A blank material 14 for forming a cylinder head 12 is metal for elongation having good heat conductivity and is cold forged by forming a mechanism to grasp the material 14 with pressure by means of a die 17, a lower die 18 and an upper die 19. The die 19 has recesses 20 for forming relief parts 15' of the material 14 and since the parts 15' are provided at the point for forming radiating fins 15 where accuracy is relatively not required, the operation for removing burrs after forming is eliminated. The need for the airtight treatment of the mounting surface of the head is eliminated as the blank material is plactically worked by cold forging. The material 14 is thus effectively utilized and resources are economized.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is utilized for molding a 7-ring head of a closed type compressor forming a refrigeration cycle of a refrigerator or the like.

(B) Prior Art The cylinder head of a conventional compressor is formed by casting iron material, aluminum die-casting, or by fixing a plurality of iron plate-shaped press parts together by brazing in a furnace.

Although cast molded bodies have rigidity, they are not suitable for complex shapes and have poor heat conduction and poor heat dissipation. Aluminum tie-cast molded bodies can be formed into complex shapes and have good heat dissipation properties, but they generate pinholes and require various air-tight treatments.
The loss will be high. The combined body of steel plate-shaped pressed parts has good heat dissipation because it can be thinned in terms of strength and pressure resistance, but since multiple parts are bonded together by furnace brazing, the adhesive surface (sealing surface) Thermal distortion remains in the compressor, which often causes leaks during compressor operation. For this reason, in the assembly of bush parts, it is necessary to adequately control the variation in materials and the temperature in the furnace. Furthermore, since the wall is thin, it is difficult to rework the mounting surface, and the walking distance is low, resulting in high cost.

(c) Purpose of the Invention In view of the above, the present invention provides a method for manufacturing a cylinder head for a compressor, which has good heat conduction, can form desired parts with high precision, and is advantageous in terms of work. It is.

(d) Structure of the Invention This invention involves forming a cylinder head by cold forging a metal material for drawing with good heat conductivity such as an aluminum alloy, and forming a relief part of the metal phase with relatively high precision using a heat dissipation fin or the like. It is characterized by being installed in locations where it is not required.

(E) Embodiment FIG. 1 shows a hermetic compressor equipped with an embodiment of the method of this invention. In this compressor, an electric element (3) and a compression element (4) are connected via a spring (2) in a case (1).
The electric element (3) rotates the foot (5) to the crankshaft, and the eccentric pin (6) of the rotating crankshaft (5) slides the piston (7) inside the crank (8). It is designed to move.

In addition to lubrication, refrigerating machine oil (9) is also used in the centrifugal pump (1) in the crankshaft (5) as shown by the arrow (A).
0> and sprinkled on the cylinder head 12) through the piston hole (11) for cooling.

The reason why the cylinder head (12) is cooled is that this cylinder functions as a passage for intake gas and discharge gas, and during normal operation, -C is pressurized by the piston (7) and cylinder (8). As the heated compressed gas is guided to the crank via the discharge valve (13), the cylinder head (12) becomes the first gas reservoir and is heated, and by heating the cylinder, the compression capacity is increased. This is because oil slunk may occur in the discharge valve (13) and the compressor may malfunction. For this reason, the cylinder head (
12) requires a material with high heat dissipation effect.

The present invention relates to a method of manufacturing such a cylinder head (12), in which an aluminum alloy for drawing is plastically worked by cold forging, and will be explained below with reference to FIG. 2. Step (a) involves cutting a metal material (14) with good thermal conductivity, such as an aluminum alloy for drawing, based on the required amount of forming. to select the round bar (14a), board shrine (14b), etc.

Process (b) is a press process to obtain the approximate shape while joining multiple materials, and is a preforming step that is added in stages when a complex shape or finished product accuracy is required. It is not necessary if the shape is

Process (C) is also press working, suction muffler (12a')
This is for molding complicated shapes such as a discharge muffler'-(12b) and the like. As described above, the cylinder head (12) is completed by cold forging, that is, a method in which a metal material is pressed between molds at room temperature or below the maximum crystallization temperature to form a part.

Step (d) is carried out when mechanical strength is required depending on the purpose of use of the cylinder head (12), and the heat treatment method is selected depending on the material of the aluminum alloy and the purpose to increase the strength. In the case of cylinders ＼・/do＜12), they are made of a soft material that is easy to process, so in order to increase the rigidity of the entire cylinder head and prevent partial warping and deformation due to bolt tightening (=j). , quenching, and tempering heat treatments are required.

Step (e) involves machining the mounting surface.
Bolt tightening is performed when the surface finish has not reached the desired state and when high-precision airtightness is required later. In the method employing cold forging of the present invention, the mounting surface is also air-tightened if necessary after cold forging, but the work is -C% lower than the aluminum die-casting work described below.

In the case of aluminum die casting, since the molten metal is instantaneously shaped into a mold and solidified, it is difficult to completely exhaust air and gas, and the formation of large pores inside the casting is unavoidable. In die-casting work, in order to air-tighten the mounting surface, new technologies such as vacuum die-casting have recently been introduced for evacuation of air and gas, but even with this new technology, the evacuation is not completed, but impregnation treatment is used as an air-tight treatment. The actual situation is whether they are doing so. In addition, in die casting operations, multiple products can be made in one extrusion depending on the structure of the mold, but in order to improve the flow of the molten metal, large runners and degassing work are required, and in addition, it is necessary to remove the molded products. It is also necessary to remove the runners afterwards.

FIG. 3 shows a sheet 1 formed by the method of the present invention. ° shows the link head (12), (15) is the heat dissipation fin part, (16)
is a screw hole.

Figure 4 shows how the cylinder head (12) is formed in step (C) by cold forging of the present invention.
18) is the lower die on which the material for forming the cylinder head (12) is placed, and (19> is the material (14) placed between the lower die (18) and
With the upper mold that pinches the material, the relief part (adjustment part) (15°)
A recess (20) is provided for forming. The relief portion (15') is provided at a location where the heat dissipation fin portion (15) is formed, which does not require relatively high precision, and therefore there is no need to remove the bulge (excess material) after molding, resulting in a process deletion. In addition, all the forming materials can be used effectively and resources can be saved.

(F) Effects of the Invention According to the present invention, since the metal material is formed by cold forging, the metal material is plastically processed and does not generate cavities unlike die casting, and therefore the mounting surface of the cylinder head is airtight. Processing can be omitted. Furthermore, since the surplus material escape portion is provided at a location such as a radiation fin where accuracy is not required to be checked, the work of removing firmness (excess material) after molding the cylinder head can be omitted.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a compressor equipped with a cylinder molded according to the present invention, Figs. FIG. 4 is a perspective view of a cylinder head molded according to the invention, and is a drawing for explaining the main steps of the invention. (12>...Cylinder head, (14)...Metal material, (15)...Radiation fin part, (15') - Relief part. Fig. 1 Fig. 2, 14

Claims (1)

[Claims] l) Forming the cylinder head by cold forging a metal material for drawing with good heat conductivity such as aluminum alloy, and
A method for manufacturing a cylinder head for a compressor, characterized in that a relief portion for surplus material is provided at a location of a radiation fin stop that does not require relatively high precision.