KR920004668B1 - Die assembly for forging metal caps of insulators - Google Patents

Abstract

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Description

Die assembly for insulator metal cap

1 is a cross-sectional view of a prior art die for forming a metal cap.

2 is a cross-sectional view of a metal cap formed by a prior art die.

3 is a perspective view of one embodiment of a die assembly for a metal cap.

4 is an enlarged exploded perspective view of a second engaging groove forming die of the die assembly shown in FIG.

5 is a front view of the metal cap blank before forging.

6 is a front view after the blank shown in FIG. 5 is forged with a flat blank.

7 is a sectional view illustrating one forging step of the metal cap blank.

8 is a bottom view of the blank bay shown in FIG.

9 is a partial cross-sectional view of the metal cap blank.

10 is a cross-sectional view illustrating the next forging step of the metal cap blank shown in FIG.

11 is a bottom view of the blank bay shown in FIG.

12 is a partial cross-sectional view of a blank.

13 is a cross-sectional view illustrating the forging step for forming the escape preventing ridge.

14 is a cross-sectional view illustrating the first of three steps for forming the coupling groove and the cutout in the coupling wall portion of the metal cap blank.

15 is a cross-sectional view illustrating a second step of three steps.

16 is a cross-sectional view taken along line XVI-XVI in FIG.

17 is a cross-sectional view illustrating a third of three steps.

18 is a plan view illustrating only the metal cap after being forged.

19 is a cross-sectional view illustrating a state in which the metal cap forged by the die assembly according to the present invention is used for the insulator.

* Explanation of symbols for main parts of the drawings

1: inner die 2: outer die

3: first coupling groove forming die 4: second coupling groove forming die

5, 12, 17: opening molding die 6: notch forming die

7: Separate drawing out die 8: Cylindrical metal cap blank

9: disc type flat blank 10, 15, 42, 51: upper die

11, 16, 41, 52: lower die 13: press knock pin

14,53: metal cap blank 18: knock pin

21, 22, 40: mounting member 23: fixing member

24: Teardrop molding die 25: Movable cap body

26: position fixing member 27: drawing member

43: metal cap 44: suspension insulator

45: adhesive 46: metal pin

The present invention relates to a metal cap forging assembly for insulator, and more particularly, to a die assembly for forging metal cap having a coupling groove for fixing the insulator metal pin and a skirt for reinforcing the insulator.

In general, metal caps of insulators for transmission lines are made of malleable or ductile cast iron by casting, and forged metal caps are used only for special purposes. The reason lies in the fact that the metal cap of the insulator, in particular its socket part, is not suitable for forging, although the metal cap of the forged insulator has inherently higher reliability in quality than the cast metal cap. Such a structure, which is not suitable for forging, requires a high cost for machining the metal cap, and therefore, the forged metal cap is inferior to the casting cap from an economic point of view.

The method of manufacturing the metal cap of the bowl-shaped suspension insulator used so far is a Japanese Patent Application Publication No. 984 / using a die assembly composed of an upper die 51 and a lower die 52 as shown in FIG. 60 is disclosed. In the above patent application, the metal cap blank 53 having the bottom cylindrical coupling wall portion 53a and the skirt portion 53b is pressed in the up and down direction to bend the lower end of the coupling wall portion 53a in the inward direction. As shown in FIG. 2, coupling grooves or socket portions 53c are formed in the coupling wall portion 53a.

However, since the metal cap die assembly of the prior art only functions to bend the cylindrical coupling wall portion 53a, by milling to form an opening 53d for introducing the insulator metal pin into the coupling groove 53c from one side. It is necessary to cut one part of the joining wall portion 53a in a subsequent step. Therefore, this additional process lowers the productivity of the insulator and is another problem that lowers the strength of the metal cap due to the fact that the forged flow lines of the joining wall portion 53a are cut when forming the opening 53d. Cause. In particular, forging flow lines that require high strength are cut because a cutout must be formed on the inner upper surface of the coupling groove 53c formed by forging in a subsequent process. This is a very important problem.

In consideration of this problem, the applicant of the branch proposes a die assembly which can form an opening at the same time as forming a joining groove inside the joining wall portion.

However, this proposed die assembly is composed of a plurality of die parts that are separable from each other, and since the die parts are each drawn out side by side, the separation operation is very complicated, which lowers the insulator productivity.

An object of the present invention is an improved insulator metal which eliminates all the drawbacks of the prior art and can improve the productivity of a metal cap with sufficient strength without cutting the forged stream lines by simple disconnection of the die from the metal cap blank. It is to provide a die assembly for cap forging.

In order to achieve this object, the die assembly for metal cap forging of insulator according to the present invention includes an inner die fitted to the skirt portion of the metal cap blank, an outer die fitted to the outside of the metal cap blank, and a blank in the axial direction of the blank. A first engaging groove having a slanted forming surface which is movably fitted to the outer die and which forms an engaging groove by pressing an end portion of the engaging wall portion of the blank in the axial direction against the inclined forming surface to bend the engaging wall portion inward; A forming die and a second joining groove forming die received in a receiving groove formed from a center to an outside of the first joining groove forming die to form an opening in the joining wall portion and to form an inside of the joining groove, The second coupling groove forming die is detachably connected to the opening forming die in the axial direction with the opening die. And a three dividable die member comprising a cut-out die formed and a separate draw die releasably connected to the cut-out die. The die assembly according to the invention further comprises a first engaging groove upper die and Coupling means installed in said opening forming die of a second joining groove forming die and engageable with each other to displace said opening forming die with respect to the movement of said first forming groove forming die away from the metal cap blank so as to be separated from the metal cap blank. do.

In a preferred embodiment, the notch forming die may be laterally drawn and moved after being separated from the metal cap blank when the separate draw die is axially drawn and moved.

It is preferable that the inclined forming surface of the first engaging groove forming die is formed into a curved surface.

The opening forming die constituting the second engaging groove forming die preferably has a curved forming surface for forming an inner circumferential surface of the engaging wall portion in an arc shape at the front edge thereof.

The die assembly for metal cap forging of insulators can improve the productivity of the metal cap by bending the joining wall portion of the metal cap blank to form the joining groove in the joining wall portion at the manufacturing steps. Since the opening is formed by the use of an opening die without cutting part of the joining wall portion or forged flow lines, the strength of the joining groove of the metal cap is improved.

Further, according to the present invention, the cutout is formed at the inner upper end of the coupling groove by the notch forming die when forming the coupling groove. When removing the die in this step, the separation draw die is first drawn out of the blank, and then the cutout forming die is moved out of the opening forming die, and then pulled out of the cutout of the blank. In this way the cutout is precisely formed in the inner upper end of the joining groove of the blank without requiring cutting or machining by milling to form the opening and cutout, so there is no cutting of the forging line of the metal cap. The strength of the cap is improved.

Upon removal of the first joining groove forming die, the opening forming die of the second joining groove forming die is disengaged with the first joining groove forming die from the metal cap blank so that the removal of the die is significantly simplified, which greatly improves the productivity of the metal cap. .

BRIEF DESCRIPTION OF DRAWINGS To understand the present invention more clearly, the preferred embodiments will be described with reference to the accompanying drawings by way of example.

3 is an enlarged perspective view of the main die assembly with the top facing downward in the state used in step 3, in particular the third of them. As will be described in detail later, these steps bend the engaging wall portion 14b of the metal cap blank 14 to form the opening 14a and the engaging groove 14f. The die assembly has an inner die 1 fitted to the upper inner surface of the skirt portion 14c of the metal cap blank 14 and a forming surface 2a fitted to the outer circumferential surface of the metal cap blank 14. An outer die 2 consisting of two die portions 2a and 2b.

In addition, the die assembly includes a first coupling groove forming die 3 which is fitted to be movable vertically into the insertion hole 2b formed in the die portion 2B adjacent to the lower portion of the forming surface 2a of the outer die 2. Include. The first coupling groove forming die 3 is formed at one end of the metal cap blank 14 in order to bend the coupling wall portion 14b inward to form the coupling groove 14f, as shown in FIG. An inclined molding surface 3a in the form of a substantially curved surface for pressing one end of the engaging wall portion 14b in the vertical direction is formed. The first engaging groove forming die 3 is also formed with an accommodating groove 3b extending from the center portion to the outer side for accommodating the second engaging groove forming die 4 to be vertically passed and brushed.

The second engaging groove forming die 4 is accommodated in the insertion groove 2c formed on one side of the outer die 2 and the receiving groove 3b of the first engaging groove forming die 3. The second engaging groove forming die 4 is shown in FIG. 4 to form an opening 14a in one side of the engaging wall portion 14b and to form a notch 14g in the upper inner surface of the engaging groove 14f. As include three detachable members.

The second joining groove forming die 4 has an opening forming die 5 having a core portion 5a formed along an edge of the curved forming surface 5b for forming the inner circumferential surface of the joining wall portion 14b in an arc shape. ).

The opening forming die 5 has only the other engaging projection at its other end, which forms the fixing means together with the engaging groove 3c in which the end of the receiving groove 3b of the first engaging groove forming die 3 is formed. (5c) is formed. When the first engaging groove forming die 3 is separated and moved upward from the metal cap blank 14 of FIG. 18, the engaging groove 3c and the engaging protrusion 5c engage with each other to remove the opening forming die 5 from each other. 1 Raise together with the joining groove forming die 3 to fall on the metal cap blank 14.

The notch forming die 6 is detachably downward from the bottom of the opening forming die 5 (i.e., upward from the top of the die 5 as shown in FIGS. 3 and 4 showing the die in a downward direction). It is connected to the opening forming die 5. The cutout forming die 6 has a coupling groove 6a extending in the longitudinal direction at its main part, and at one end, an integral disk-shaped block core portion corresponding to the forming surface 5b of the opening forming die 5. 6b is formed. In addition, on one side of the core portion 6b of the notch forming die 6, the engaging portion 6c which engages with the side edge of the opening forming die 5 in order to prevent the forming die 6 from deviating laterally. Is formed. The separating lead-out die 7 is connected to the notch forming die 6 so as to be laterally detachable from its bottom face (upper face in FIGS. 3 and 4). The separating lead-out die 7 is provided with a coupling pin 7a for slidingly engaging the engaging groove 6a of the cutout forming die 6 on its upper surface, and at one end thereof, the cutout forming die 6 The core part 7b corresponding to the core part 6b is formed. When the separate draw die 7 is withdrawn out of the assembly as in FIG. 16 or moved in the left direction (arrow direction on the left in FIG. 16) by a predetermined distance, the cutout forming die 6 is It falls onto the lower portion 7c, whereby the notch forming die 6 is disengaged downward from the notch 14g of the metal cap blank 14. Then, as shown in FIG. 16, the engaging pin 7a touches the left end of the engaging groove 6a so that the cutout forming die 6 is left along with the separating lead-out die 7 in the direction of the left arrow of FIG. Withdraw or withdraw.

A method of forming the metal cap 43 by forging by the dies 1-7 configured as described above will be described with reference to FIGS. 5 to 18. First, the metal cap blank 8 is cut into a cylindrical shape of a circular cross section of a predetermined length shown in FIG. 5 in a long circular rod. Then, as shown in FIG. 6, the cylindrical blank 8 is forged in the axial direction with the upper and lower forging dies to form a disk-shaped flat blank 9 having a projection 9a at the center of the bottom surface thereof.

The flat blank 9 then consists of an upper die 10, a lower die 11, an apertured die 12 and a press knock pin 13 as shown in FIGS. Forging to form a blank 14 for the metal cap 43 that is forged in the cavity of the die assembly. The blank 14 thus formed has an integrally formed coupling wall portion 14b having a horseshoe-shaped or U-shaped opening on one side thereof as shown in FIG. 8 at its lower end, and a cylindrical skirt portion 14c at its upper end. The partition wall 14d is formed in the intermediate part between the skirt part 14c and the engaging wall part 14b like 7th degree | time.

The blank 14 thus formed is forged in its cavity by another forging die assembly consisting of an upper die 15, a lower die 16, an opening forming die 17 and a knock pin 18, thus joining The wall portion 14b is elongated in the axial direction of the blank 14, and at the same time, a step portion 14e of an L-shaped cross section is formed on the circumference of the skirt portion 14c to the outside. Thin as 12 tiles.

Then, as shown in FIG. 13, at least the skirt portion 14c between the lower die 41 fixed to the mounting member 40 of the upper surface S of the annular step portion 14e of the blank 14. Pressed inward by an upper die 42 having an inner cavity contacting the outer end of the end portion of the skirt portion 14c by bending the vicinity of the bottom portion E of the skirt portion 14c and the annular step portion 14e inward. By forming two container portions 141 on the inner circumferential surface of the metal cap 43, the metal cap 43 is prevented from detaching when the metal cap 43 is attached to the insulator as in the nineteenth degree.

From now on, the die assembly according to the invention bends the end of the engaging wall portion 14b of the metal cap blank 14 inward, as shown in FIGS. 14, 15 and 17 degrees, the inner side of the engaging wall portion 14b. Forming a coupling groove 14f in the groove, and three steps of forming the notch 14g in the inner upper surface of the coupling groove 14f.

In the first step, a structure similar to the inner die 1 mounted on the mounting member 21, the tie portion 2A of the outer die 2, and the first engaging groove forming die 3, as shown in FIG. Various dies mounted between a pair of forming dies 3X and 3Y, an opening forming die 5, a notch forming die 6, a separate drawing die 7 and other mounting members 21 and 22 are used. . The metal cap blank 14, which is fitted to and supported by the inner die 1, is clamped by the fastening member 23 while being clamped by the die portion 2A that surrounds and moves towards it. It is fixed. Then, the notch forming die 6 and the separating lead-out die 7 are inserted from the side of the metal cap blank 14 into the cavity of the horseshoe or U-shaped engaging wall portion 14b of the metal cap blank 14. . Then, the opening forming die 5 is lowered onto the notch forming die 6, and the pair of forming dies 3X and 3Y are continuously lowered onto the metal cap blank 14 to form the U-shaped engaging wall portion 14b. The engaging groove 14f and the notch 14g are formed.

After this forming operation, the pair of forming dies 3X, 3Y for raising the mounting member 22 upward and forming the fixing member 2 and the first coupling groove 14 is coupled to the wall portion 14b of the metal cap blank 14. To upward from. As the forming die 3Y is raised, its engaging groove 3c engages with the engaging protrusion 5c, whereby the opening forming die 5 is separated from the metal cap blank 14 and together with the forming die 3Y. It is raised upwards. Under this condition, the metal cap blank 14 is combined with the mounting member 21, the inner die, the die portion 2A of the outer die 2, the notch forming die 6, and the separating take-out die 7 It is moved to the right in the direction of the arrow on the right side of the figure to prepare for the next second step shown in FIG.

In the second step, one forming die 3z is used as the first joining groove forming die instead of two forming dies 3X and 3Y. As in the first step, the fixing member 23 descends to clamp and fix the die portion 2A from the outside. In this state, the opening forming die 5 is lowered onto the notch forming die 6, and then the forming die 3z is lowered to bring the joining wall portion 14b of the metal cap blank 14 into a shape close to its predetermined shape. Form. Further, in the second step, the movable cam body 25 is lowered so that the accumulating portion forming die 24 is coupled to the wall portion of the metal cap blank 14 opposite the notch forming die 6 and the separating lead-out die 7. It moves toward 14b, and the accumulation part 14h is formed in the outer surface of the coupling wall part 14b.

After this forming operation, the mounting member 22 is moved upward to move the forming die 3z and the fixing members 23 as the first engaging groove forming die upward from the engaging wall portion 14b of the metal cap blank. In this case, as the forming die 3z is raised, the engaging groove 3c is engaged with the engaging protrusion 5c, so that the opening forming die 5 is separated from the metal cap blank 14 together with the forming die 3z. Let's do it. When the mounting member 22 is raised, the movable cap body 25 of FIG. 16 also rises to withdraw the accumulator forming die 24 to the outside. In this state, the metal cap blank 14 includes the mounting member 21, the inner die 1, the forming die portion 2A of the outer die 2, the notch forming die 6, and the separate drawing die 7. And move to the right in the direction of the arrow on the right in FIG. 16, and proceed to the third step shown in FIG.

In the third step, the forming dies shown in FIGS. 3 and 4 are used. As in the first and second steps, the fixing member 23 is lowered to clamp and fix the molding die or the die portion 2A from the outside. In this state, the opening forming die 5 is lowered onto the notch forming die 6, and then the die portion 2B and the first engaging groove forming die 3 of the outer die 2 are made of metal cap blanks 14 ) Is continuously lowered to form a joining wall portion 14b in a predetermined shape to be finished. As a result, a coupling groove 14f having an opening 14a on one side is formed inside the coupling wall portion 14b, and the coupling groove 14f is notched as shown in FIG. 18 on the upper inner surface thereof. ) Is formed.

After this molding operation, the mounting member 22 is raised, and the fixing member 23, the first joining groove forming die 3 and the die portion 2B are lifted from the joining wall portion 14b of the metal cap blank 14. Let's do it. In this case, as the first engaging groove forming die 3 is raised, the engaging groove 3c is engaged with the engaging projection 5c, so that the opening forming die 5 is combined with the first engaging groove forming die 3. The upper portion is separated from the metal cap blank 14.

Further, at the end of the third molding step, the position fixing member 26 shown in FIG. 16 is lifted by the upward movement of the mounting member 22 to open the outside of the separation take-out die 7. In this state, the drawing member 27 is moved laterally to move the separating drawing die 7 to the left in the direction of the arrow on the left in FIG. 16 by the engaging pin 27a and the engaging opening 7d. When the separating lead-out die 7 is moved by a predetermined distance, when the cutout forming die 6 is lowered onto the lower portion or the groove 7c of the separating take-out die 7, the core portion 6b of the cut-out forming die 6 ) Is separated downward from the notch 14g. Thereafter, the engaging pin 7a is engaged with the left end of the engaging groove 6a, and as shown in FIG. 16, the notch forming die 6 is left along with the separating lead-out die 7 (in the direction of the arrow on the left in FIG. 16). Is moved to.

In addition, after disengaging the metal cap from the dies, the metal cap is fitted onto the head 44a of the suspension insulator 44 by an adhesive 45 as shown in FIG. 18, for example, as shown in FIG. . On the other hand, the lower end of the metal pin 46 fixed to the insulator 44 is engaged with the coupling groove 14f at the upper end of the metal cam 43.

The present invention may be practiced as follows.

In this embodiment, the opening 14a is formed at the time of forming the engaging wall portion 14b. In contrast, the opening 14a may be formed in the forging steps with the first joining groove forming die 3 and the second joining groove forming die 4. In this case, it is preferable that the joining wall portion of the portion where the opening 14a is to be formed is made thin in advance.

As described above, the die assembly of the metal cap according to the present invention can form the opening at the same time to form the coupling groove by bending the coupling wall portion in the manufacturing steps, and also the second coupling with high precision without special operations such as cutting By forging with a groove forming die to form cutouts and openings in the joining wall, the strength of the defect grooves is increased without cutting the forged flow line of the joining wall. Furthermore, when the first engaging groove forming die is detached from the metal cap blank, the opening forming die of the second engaging groove forming die is released together with the first engaging groove forming die, thereby significantly simplifying the operation of the die leaving the blank. The productivity of the metal cap can be reconsidered.

The present invention has been described with reference to the preferred embodiment as described above, but not limited to those skilled in the art of the present invention will be able to various modifications and changes without departing from the spirit and viewpoint of the present invention.

Claims (9)

An inner die fitted to the skirt portion of the metal cap blank, an outer die fitted to the outside of the metal cap blank, and an outer die fitted to the outer die so as to be movable in the axial direction of the blank, the inclined forming surface of the end of the joining wall portion of the blank A first joining groove forming die having an inclined forming surface for forming a joining groove by pressing in the axial direction with respect to the axial direction, and forming an opening in the joining wall portion and forming an inside of the joining groove. A second engaging groove forming die accommodated in the receiving groove formed in the first engaging groove forming die from its center to an outer side thereof; The second joining groove forming die includes three divided dies including an opening forming die, a cutout forming die detachably connected to the opening forming die in an axial direction, and a separate drawing die releasably connected to the cutout forming die. Formed of members; The opening forming die may also be displaced in relation to the separation of the first engaging groove forming die installed in the opening forming die of the first engaging groove forming die and the second engaging groove forming die and falling from the metal cap blank. A die assembly for metal cap forging of insulator, characterized in that it comprises a joining member that is engageable with each other to separate. The die assembly of claim 1, wherein the inclined forming surface of the first coupling groove forming die is formed as a curved surface. The method of claim 1, wherein the opening forming die is formed with a stepped coupling protrusion, the first coupling groove forming die is formed with a coupling groove having an end in the receiving groove, the coupling member is the coupling protrusion And Die assembly for metal cap forging of insulator, characterized in that consisting of a coupling groove. The die assembly for metal cap forging of insulator according to claim 1, wherein a curved forming surface for forming the inner circumferential surface of the joining wall portion in an arc shape is formed at the front edge thereof. 5. The metal cap end of insulator according to claim 4, wherein the cutout forming die has a disc-shaped integral convex core portion corresponding to the curved forming surface of the opening forming die at one end thereof. Quiet die assembly. 6. The cutout forming die of claim 5, wherein the cutout forming die has an engagement portion formed at one side of the convex core portion to engage the side edge of the opening forming die to prevent the cutout forming die from lateral separation. Die assembly for metal cap forging of insulator. 2. The die for metal cap forging of claim 1, wherein the cutout molding die is separated from the metal cap blank and moved laterally when the separate drawing die is drawn out and moved laterally. Assembly. 2. The cutout forming die of claim 1, wherein a major portion thereof is formed with a coupling groove extending in the longitudinal direction, and the separation draw-out die is slidably coupled to the surface of the joining groove of the notch forming die. Die assembly for the metal cap forging of insulator, characterized in that the coupling pin is formed. The die assembly for metal cap forging of insulator according to claim 1, wherein a core portion corresponding to the core portion of the cutout forming die is formed at one end thereof.

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