WO2019212088A1

WO2019212088A1 - Method for manufacturing pulley for automobile compressor by using compound forging and pulley manufactured thereby

Info

Publication number: WO2019212088A1
Application number: PCT/KR2018/007210
Authority: WO
Inventors: 한준규; 정상근
Original assignee: (주)한국정공
Priority date: 2018-05-02
Filing date: 2018-06-26
Publication date: 2019-11-07
Also published as: KR20190126491A

Abstract

The present invention relates to a method for manufacturing a pulley for an automobile compressor by using compound forging, and a pulley manufactured thereby. The method comprises: a first forging process (S10) based on free forging; a second forging process (S20) based on hot forging; a third forging process (S30) based on cold forging; a piercing process (S40); and a precise cutting process (S50). In the second forging process (S20), the rear inner peripheral surface of an outer die (102) and the front outer peripheral surface of a punch (103) are indented in shapes corresponding to those of an inner rim (131) and a preliminary outer rim (132a), respectively, and a material is sealed/extruded rearward through hot forging, thereby forming the inner rim (131) and the preliminary outer rim (132a). In the third forging process (S30), the front inner peripheral surface of the outer die (102) is indented in a shape corresponding to that of an outer rim (132), and the preliminary outer rim (132a) is laterally extruded through cold forging, thereby forming the outer rim (132). Accordingly, it is possible to manufacture high-quality pulleys having high productivity and excellent dimension preciseness and mechanical characteristics.

Description

Method for manufacturing pulley for automobile compressor using compound forging and its pulley

The present invention relates to a method for manufacturing a pulley for an automobile compressor using a composite forging and a pulley thereof, and more particularly, to increase productivity and to minimize mechanical waste while improving the manufacturing process of a conventional vehicle compressor pulley. The present invention relates to a technique for producing a high quality pulley with excellent properties.

In general, the air conditioning system of a vehicle is a general term for a system that is in charge of heating, cooling, and ventilating a vehicle.

The automotive air conditioning system introduces air from the outside of the vehicle and purifies it through the HVAC (air conditioning system) system to quickly recycle the inside of the vehicle, and heat the air by a heater core connected to the heated coolant of the engine cooling system, The main function is to cool the air by the evaporator included in the cooling system to make the room a comfortable space.

Automotive air conditioning system mainly includes an evaporator, a compressor, a condenser, and an expansion valve. The evaporator is cooled by evaporating the heat of the surrounding air using liquid refrigerant. The compressor circulates and compresses the refrigerant gas vaporized by the evaporator to become a low temperature and low pressure state, and recompresses the high temperature and high pressure state for easy liquefaction. The condenser converts the refrigerant gas in the high temperature and high pressure state into the liquid refrigerant of the low temperature and high pressure by exchanging heat with the ambient air by the compressor. The expansion valve lowers the pressure so as to be suitable for expanding and vaporizing the liquid refrigerant passing through the capacitor.

In particular, the compressor of the automotive air conditioning system drives the pulley of the compressor by the crankshaft and the drive belt of the engine, and the power transmitted to the pulley induces the piston movement by rotating the swash plate through the disk to induce low temperature and low pressure. It sucks the refrigerant gas, recompresses the superheated steam at high temperature and high pressure, and transfers it to the condenser. Therefore, the pulley is generally manufactured by molding a metal material to accommodate the tensile force of the drive belt.

A conventional pulley for a compressor is mainly manufactured by a hot forging method. Referring to FIG. 7, a schematic manufacturing process of the pulley for cutting is performed by cutting and heating a material (S101), and a nose in which a magnetic clutch is interposed by hot forging. Forming a hollow portion for penetrating a portion and a shaft (S102), perforating the hollow by a punch (S103), and roughing the outer circumferential surface of the material to form a belt groove in which the belt is wound (S104); It comprises a step (S105) of drilling the slot of the coil portion, and the step (S106) of forming the irregularities by finishing the belt groove.

As an example of the known technology, the method of manufacturing a compressor pulley for automobile air conditioner of Korea Patent No. 10-0921443 hot forging a steel material at 1300 ℃ to form an annular inlet and a central through-hole in the center and a preliminary undercut outside the bottom surface The preform is formed, and the preform is positioned on the lower die, and then configured to drop the upper die with a cylindrical mandrel and an upper punch integrally attached around the outer surface of the cylindrical mandrel to a pressure of 600 t.

As another example, the method of manufacturing a belt pulley for automobiles of Korea Patent Publication No. 10-2008-0088852 in the method for manufacturing a pulley for automobiles by step plastic processing of a material having a circular through-hole in the center, cutting the prepared round bar Material cutting process to prepare a circular material with any thickness and cold forging to make the round bar with the appropriate thickness and appearance. Through the first forging process to form a press-in part projecting downward to form a shaft hole in the center, a piercing process to complete the shaft hole and the shaft tube body part through the press-in part, and a mechanical cutting process on the outer body part. Belt guide and belt groove forming process, finishing process and painting process And comprising the step of sex.

As a method of manufacturing a pulley for an automobile compressor to which the conventional technology as described above is applied, a method of forming a metallic material by hot forging is generally used.

Hot forging has the advantage of saving energy, high productivity and easy molding of complex shapes by heating the material to a high temperature close to the firing temperature to reduce the deformation resistance and then giving permanent deformation.

However, since hot forging is performed at very high temperatures of 1000 ° C or higher, it causes defects due to decarburization, surface defects and scales, and deterioration of the working environment, and also takes into account the molten metal that is pushed out to the mold line between the upper mold and the lower mold. Since about 20-30% of the product weight is added to the extra material to generate a flash, there is a problem of causing waste of the material.

In particular, hot forging is a belt having an inner and an out rim, since the product heated to a high temperature can be molded only by a method of backward extrusion of a material due to a problem that premature wear is caused due to deterioration if the product heated to a mold stays in the mold for a long time. In order to form the grooves, it is inevitable to carry out the cutting step, which leads to waste of additional materials.

On the other hand, in the prior art as another example has been known a method for producing a pulley by cold forging.

Cold forging is formed by plastically processing the material at room temperature, thereby improving mechanical properties while excluding heat treatment by work hardening during plastic deformation. In addition, unlike hot forging, there is no scale loss due to heating, so that the material recovery rate is high and the dimensional accuracy is excellent, so that post-processing can be excluded or reduced and forward extrusion is possible.

However, cold forging has a disadvantage in that energy consumption is large because high deformation pressure is required because the deformation resistance of the material is large.

The present invention provides a pulley manufacturing method included in a compressor of an automotive air conditioning system.

The primary forging process (S10) of cutting the disc-shaped material and freely forging the material heated to 1200 ± 50 ° C. to increase the disc shape to 110-120 mm in diameter.

The secondary forging process of inserting the first forged material 101 into the mold to indent the hollow portion 110 and the coil housing 120 of the pulley to a predetermined depth and form the inner rim 131 of the belt groove 130. (S20),

A third forging step (S30) of forming the out rim 132 of the belt groove 130 by inserting the second forged molding into a mold;

A piercing process (S40) for drilling the hollow 111 and the slot 121 in the hollow portion 110 and the coil housing 120 of the third forged molding,

A finishing step (S50) of forming an uneven surface 133 by finishing the outer peripheral surface of the belt groove 130 of the pierced molding in a ring shape;

In the secondary forging step (S20),

The back inner circumferential surface of the out die 102 and the front outer circumferential surface of the punch 103 are retracted into a shape corresponding to the inner rim 131 and the preliminary out rim 132a, respectively, and the inner rim is closed by extruded by hot forging. 131 and a preliminary out rim 132a,

In the third forging step (S30),

The front inner circumferential surface of the out die 102 is retracted into a shape corresponding to the out rim 132, and the preliminary out rim 132a is formed by cold forging to form the out rim 132, thereby forming a pulley manufacturing process. It is possible to achieve the purpose of efficient and high quality pulleys.

The present invention has the advantage of improving the problems of the prior art by hot forging or cold forging in manufacturing a compression pulley mounted in an air conditioning system of a vehicle.

In particular, the present invention has the effect of increasing the productivity by eliminating the roughing process for the formation of the belt grooves as in the prior art, thereby minimizing waste due to extra input and roughing of the material.

In addition, there is an advantage that high-quality pulleys can be manufactured by deriving high dimensional precision and mechanical properties while saving energy by back extrusion by hot forging and lateral extrusion by cold forging.

1 is a schematic process flow diagram of a method for manufacturing a pulley for an automobile compressor using a compound forging according to the present invention.

Figure 2 is a process diagram of a method for manufacturing a pulley for an automobile compressor using a composite forging according to the present invention.

Figure 3 is a block diagram showing the state of the secondary forging process of the pulley manufacturing method for automobile compressor using a composite forging according to the present invention.

Figure 4 is a block diagram showing a state of the third forging process of the pulley manufacturing method for automobile compressor using a composite forging according to the present invention.

5 to 6 is a cross-sectional view and a perspective view of a pulley manufactured by a method for manufacturing a pulley for an automobile compressor using a composite forging according to the present invention.

7 is a schematic process diagram of a conventional method for manufacturing a pulley by hot forging.

Method for manufacturing a pulley for an automobile compressor using a composite forging to which the technique of the present invention is applied, and the pulley is provided with a hollow portion 110 and a coil housing 120 in manufacturing a pulley for a compressor mounted in an automotive air conditioning system. Minimizing energy and material waste by constructing a manufacturing method by a composite forging that uses a combination of hot forging and cold forging to form a pulley forming a belt groove 130 having a rim 131 and an out rim 132. However, it is noted that the present invention relates to a method of manufacturing a pulley for a compressor and a pulley manufactured accordingly, to impart excellent dimensional accuracy and mechanical properties.

Pulleys for automobile compressors using the composite forging of the present invention for this purpose is largely as shown in Figure 1 primary forging step (S10) by free forging, secondary forging step (S20) by hot forging, It consists of a 3rd forging process by cold forging (S30), a piercing process (S40), and a finishing process (S50), and is as follows specifically ,.

The first forging step (S10) is a process of cutting the disk-shaped material and free forging the material heated to 1200 ± 50 ℃ to increase the disk shape of 110 ~ 120mm in diameter.

The material is provided in a disk shape made of a metal material and heated to the temperature and then cooled slowly to remove residual stress and to refine the crystal grains to beat the hammer with a ductility to increase the diameter to a level suitable for the general specifications of the compressor pulley. give.

In the secondary forging process (S20), the first forged material 101 is introduced into a mold, and the hollow portion 110 and the coil housing 120 of the pulley are recessed to a predetermined depth and the inner rim of the belt groove 130 is formed ( 131).

As shown in FIG. 6, the pulley manufactured according to the present invention includes a hollow part 110 forming a hollow 111 through which a shaft for rotating a swash plate of the compressor is interposed, and a coil housing 120 with a magnetic coil interposed therebetween. The outer circumferential surface is provided with a belt groove 130 having an inner rim 131 and an out rim 132.

In the secondary forging step S20, the inner rim 131 is formed by hot forging, and a preliminary out rim 132a for forming the out rim 132 is formed.

As shown in FIG. 3, the mold used in the secondary forging process S20 includes an out die 102 forming the outer shape of the pulley, a mandrel (unsigned) for forming the hollow portion 110 of the pulley; And an insert die (unsigned) for forming the coil housing 120 of the pulley, and includes a punch 103 for pressing the material 101.

In particular, in the second forging process (S20), the rear inner peripheral surface of the out die 102 and the front outer peripheral surface of the punch 103 are retracted into shapes corresponding to the inner rim 131 and the preliminary out rim 132a, respectively, The material 101 is pressurized using the 103 to extrude backwardly.

Therefore, the inner rim 131 protrudes in the inner circumferential direction of the raw material 101, and the preliminary out rim 132a is formed on the outer surface of the raw material 101.

Since the temperature of the raw material 101 at the time of hot forging by the secondary forging process (S20) is close to 1200 ° C., in order to prevent deterioration of the mold, the back extrusion may be made. Therefore, the inner rim 131 formed at the rear (inner) side of the mold can be formed by hermetic extrusion, but the out rim 132, which should be formed at the front (outer) side, is formed at a high temperature as a mold line of both molds. The molten metal is pushed out, making it difficult to form.

The third forging process (S30) is a process of forming the out rim 132 of the belt groove 130 by inserting the secondary forged molding to the mold.

In particular, in the third forging process (S30) to form the outrim 132 by cold forging to complete the belt groove 130.

As shown in FIG. 4, in the third forging process S30, the front inner circumferential surface of the out die 102 is retracted into a shape corresponding to the out rim 132, and the preliminary out rim 132a is formed using the punch 103. As it is pressurized by the side extrusion, it is formed to protrude the outrim 132 in the circumferential direction similar to the inner rim 131.

Since the temperature of the molded product during the cold forging by the third forging process (S30) is cooled to near room temperature, unlike the hot forging, it is possible to derive an accurate dimension even in the vicinity of the mold line to form the outrim 132. In addition, the effect of reinforcing the mechanical properties such as increasing the hardness of the poly due to the densification of the tissue.

Therefore, the present invention can form the belt groove 130 by excluding the forming process that causes waste of the material 101 by the secondary forging step (S20) and the third forging step (S30) as in the prior art. have.

The piercing process (S40) is a process of punching the hollow 111 and the slot 121 in the hollow part 110 and the coil housing 120 of the third forged molding.

Pressing the hollow portion 110 and the coil housing 120 formed in the secondary forging process (S20) using a punch 103 to fix the slot 111 through which the shaft penetrates and the magnet clutch. Form by drilling.

In the finishing step (S50) is a step of forming the concave-convex surface 133 by finishing the outer peripheral surface of the belt groove 130 of the pierced molding in a ring shape. The uneven surface 133 is formed to serve to prevent the belt wound around the belt groove 130 from the pulley together with the above-described inner rim 131 and the out rim 132.

The pulley manufactured by the method of manufacturing a pulley for an automobile compressor using a compound forging according to the present invention as described above has a configuration as shown in Figures 5 to 6, mounted on one side of the compressor of the air conditioning system crank engine Interlocked with the shaft and the drive belt is provided to transfer power to the swash plate of the compressor. Since the operation relationship of the pulley for the compressor may refer to a well-known technology, a detailed description thereof will be omitted.

The method for manufacturing a pulley for an automobile compressor using a compound forging according to the present invention as described above is a hot forging method having a disadvantage of low material recovery rate and only back extrusion, compared to the advantages of energy saving due to low processing pressure, and high dimensional accuracy. It constitutes a pulley manufacturing method that uses a cold forging method that has the disadvantage that a high processing pressure is required compared to the advantage that the front or side extrusion is possible.

Therefore, in the prior art as shown in FIG. 7, in particular, the roughness after the step S104 for roughening the outer circumferential surface of the pulley to form the belt groove 130 is unavoidable, such as roughing after inputting extra materials. Problems such as waste of material, delay of processing time and deterioration of dimensional accuracy can be eliminated.

In addition, in the prior art, it is difficult to derive a stable workability and dimensional precision by performing the step S103 of punching the hollow and performing the belt groove roughing step S104 and the step S105 of slotting after demolding. The invention is configured to perform the perforation of the hollow 111 and the slot 121 sequentially in the piercing process (S40) as a later step after completing the main shape of the pulley through the first to third forging step (S10 ~ S30). Therefore, there is an advantage that it is possible to derive high dimensional precision and workability and to realize process efficiency.

Pulleys for automobile compressors using a composite forging applied to the technology of the present invention is expected to be very industrially available because there is an advantage such as manufacturing a high quality pulley with high productivity.

Claims

In the pulley manufacturing method provided in the compressor of the automotive air conditioning system,

The primary forging process (S10) of cutting the disc-shaped material and freely forging the material heated to 1200 ± 50 ° C. to increase the disc shape to 110-120 mm in diameter.

The secondary forging process of inserting the first forged material 101 into the mold to indent the hollow portion 110 and the coil housing 120 of the pulley to a predetermined depth and form the inner rim 131 of the belt groove 130. (S20),

A third forging step (S30) of forming the out rim 132 of the belt groove 130 by inserting the second forged molding into a mold;

A piercing process (S40) for drilling the hollow 111 and the slot 121 in the hollow portion 110 and the coil housing 120 of the third forged molding,

A finishing step (S50) of forming an uneven surface 133 by finishing the outer peripheral surface of the belt groove 130 of the pierced molding in a ring shape;

In the secondary forging step (S20),

The back inner circumferential surface of the out die 102 and the front outer circumferential surface of the punch 103 are retracted into a shape corresponding to the inner rim 131 and the preliminary out rim 132a, respectively, and the inner rim is closed by extruded by hot forging. 131 and a preliminary out rim 132a,

In the third forging step (S30),

Composite forging, characterized in that the front inner circumferential surface of the out-die 102 is retracted into a shape corresponding to the outrim 132, and the preliminary outrim 132a by cold forging to form the outrim 132 Method for manufacturing a pulley for an automobile compressor using the pulley.
Pulley for automobile compressor using a composite forging, characterized in that the manufacturing by claim 1.