JP2798864B2 - Roll forming turning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll forming and turning apparatus capable of continuously performing roll forming and turning in forming a ring formed body such as a piston ring for an engine.

[0002]

2. Description of the Related Art A piston for a diesel engine is made of a metal material having high wear resistance and heat resistance so that a coolant can be efficiently cooled particularly in the vicinity of a top ring groove, and circular flanges are provided at both ends of a cylindrical neck. In many cases, a wear-resistant ring processed into a ring molded body having a portion is used. This kind of wear ring can be manufactured by casting since it is attached to the back of the ring groove of the piston as a body tube that can guide lubricating oil. Therefore, the dimensional accuracy required at the time of molding is extremely severe, and the influence of the quality of the molding method on the piston cooling effect is great. Therefore, it has become relatively easy to manufacture a thin sheet metal made of, for example, stainless steel by roll forming, welding and forming it with a ring trager for inserting a piston ring, and casting this into a piston.

A conventional roll forming apparatus used for roll forming such a ring formed body such as a wear-resistant ring has the shape shown in each of the forming stages in FIGS. 3 (A) to 3 (D). The roll forming apparatus 1 shown in FIG. 1 is a combination forming die 4 in which a cylindrical forming die half 2 having a reduced diameter portion at an end face and a cylindrical forming die half 3 are butt-joined to each other at an end face so as to be fastened and separated. And a roller 6 which can be advanced and retracted into a groove 5 having a U-shaped cross section formed at a portion of the butted end face of the combination mold 4.
In molding, first, a pair of mold halves 2 and 3 are coaxially fastened by fastening means (not shown) such as bolts.
The combination mold 4 shown in FIG. next,
A hoop material 7 made of a metal tubular thin plate material shown in FIG. Then, after aligning the central portion of the hoop material 7 with the center of the groove 5, the hoop material 7 is rotated together with the combination mold 4.

On the other hand, the roller 6 has a width obtained by subtracting twice the thickness of the hoop material 7 from the groove width of the U-shaped groove 5, and rotates the roller 6 in the opposite direction to the combination mold 4. 3B, the roller 6 is further pressed inward from the groove 5 as shown in FIG. 3B. As a result, as shown in FIG. 4B, the hoop material 7 is first formed into a ring intermediate, which is a stage before being formed into the ring formed body 8, and the neck 8a is gradually formed by a necking process during this period. Is done. Therefore,
Further, as shown in FIG. 3 (C), while the roller 6 is being rotated, the hoop material 7 is pressed into the groove 5, and as shown in FIG. 4 (C), the neck 8a of the ring intermediate body is formed. Are molded into a shape close to the final molded body having flanges 8b at both ends of the molded body. Then, as shown in FIG. 3D, the necking and flaring steps are further advanced, and in the final stage, the ring molded body 8 shown in FIG. 4D is completed. For this reason,
Then, by releasing the fastening of the mold halves 2 and 3, the completed ring molded body 8 can be removed from the inside of the groove 5.

[0005]

According to the above-mentioned conventional method for forming a ring molded body 8, when the roller 6 is pressed against the groove 5 having a U-shaped cross section while rotating, the cylindrical neck 8a is formed. Immediately before the ring molded body 8 having the circular flanges 8b at both ends is completed, the ring molded body 8 which is almost completed but has not yet attained the required dimensions falls into the groove 5, and the inside of the neck 8a Since there is no means for restricting the circumference, the combination mold 4 and the roller 6 only rotate in opposite directions, so that the mold regulation for the ring molded body 8 is limited to only one place between the groove 5 and the roller 6. Since the inner circumference of the ring molded body 8 is left unrestricted, there is a problem that dimensional accuracy in the flaring process cannot be obtained.

In the conventional roll forming apparatus 1, in order to finish the outer dimensions of the roll-formed ring formed body into a predetermined shape after processing, the mold half 3 is first separated from the mold half 2 to remove the ring. A method of removing the molded body 8, attaching the ring molded body 8 to a dedicated turning machine (not shown) installed at another place, and finishing the external dimensions to required dimensions using a turning tool such as a cutting tool. Depended. However, since the ring formed body 8 having the U-shaped cross section is a thin sheet metal, it is easily deformed by a small external force.
There is a risk of being deformed by mistake during the transfer to the turning machine, and the ring formed body formed by roll forming is mounted on the turning machine using a chuck or the like that engages with its neck 8a. However, it is difficult to exactly match the center axis with the rotation center axis of the turning machine, and there is some variation in the mounting state, so the dimensional accuracy of the external dimensions finished by the turning machine is not so large. Not expensive
In addition, there is a problem that it takes a long time to move the workpiece from the roll forming apparatus to the turning machine, so that the overall work efficiency is poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is particularly advantageous in that a floating ring is loosely fitted into a molding groove of a combined mold which is formed by combining a pair of mold halves and fastened. In the final stage of roll forming, the inner periphery of the neck of the ring formed body is regulated by a floating ring to improve the dimensional accuracy of the ring formed body, and after the roll forming, the floating ring is coaxially fixed to the ring formed body with a jig, and the ring is formed. An object of the present invention is to enable turning with a turning tool while a body is fitted in a mold.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a ring forming method comprising a pair of mold halves forming a forming groove, having a cylindrical neck and circular flanges at both ends of the neck. A cylindrical material to be formed into a body has a combination mold that is fitted and fitted over the molding groove, and has an outer diameter that is the same as the inner diameter of the ring molded body. A floating ring to be fitted, and a width obtained by subtracting twice the thickness of the cylindrical material from the width of the molding groove, and the cylindrical material fitted and mounted to the combination molding die, And a roller that presses and rolls while rotating relatively in the opposite direction, and is engaged with the floating ring after the roller is formed, and the ring formed body is coaxially fixed to the combination mold via the floating ring. And jig, and turning the ring shaped body which is coaxially fixed to the combination mold, it is characterized in that it comprises a turning tool to finish the outer shape of the required dimensions.

Further, the present invention is characterized in that the combination mold comprises a receiving mold and a press mold which are provided so that the molding end faces are coaxially opposed to each other, and which are provided so as to be able to approach and separate from each other via a molding groove. Further, the floating ring has a stepped engagement hole to be engaged with the jig, and is positioned in a radial direction and an axial direction when the jig is engaged with the stepped engagement hole. In addition, the jig is slidably disposed coaxially in the one molding half, and can be selectively engaged and disengaged with the floating ring or the other molding half. It is characterized in that it engages with the other mold half and engages with the floating ring during turning.

[0010]

According to the apparatus of the present invention, a floating ring having the same outer diameter as the inner diameter of the ring molded body is loosely fitted in the molding groove of the combination mold comprising a pair of mold halves, and the molding groove is formed. Pressing the hoop material fitted over the combination mold with the roller having a width smaller than the groove width of the molding groove while rotating in the opposite direction relative to the combination mold, the same as the outer diameter of the floating ring. Roll forming into a ring molded body with the inner diameter of the dimensions, then engage the jig that had been detached from the floating ring during the roll forming with the floating ring, and coaxially formed the ring molded body through the floating ring to the combination mold By finishing the outer shape of required dimensions in a fixed state, roll forming and turning can be performed accurately and efficiently by the same apparatus.

[0011]

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view of a main part showing a forming process according to an embodiment of the roll forming and turning apparatus of the present invention. FIG. 2 is a ring formed body formed by the roll forming and turning apparatus shown in FIG. It is a perspective view which shows the state in each shaping | molding process stage.

The ring forming apparatus 11 shown in FIGS. 1 (A) to 1 (F) is a combined forming die 14 in which a pair of forming halves 12, 13 are formed by forming a forming groove 15 between opposing forming end faces. A jig 20 coaxially slidably arranged in one mold half 12, and a floating ring having an outer diameter equal to the inner diameter of the ring molded body 18 and fitted in the molding groove 15. And a roller 16 having a width obtained by subtracting twice the thickness of the hoop material 17 from the width of the molding groove 15.
And a turning tool 21 for turning the outer shape of the ring formed body 18 after the roll forming is completed. The ring molded body 18 is molded from a hoop material 17 made of a thin tubular metal material shown in FIG. 2A, and has a cylindrical neck portion 18a and circular flange portions 18b at both ends. It is formed into a shape.

In the combination mold 14 used for molding, a pair of mold halves 12 and 13 provided with the molding end faces coaxially opposed to each other so as to be able to approach and separate from each other constitute a receiving mold and a press mold for roll molding. And each has a through hole 1
2a and 13a are coaxially drilled. Also, the through hole 13a
For about, counterbore processing the opening to about twice the diameter,
It is a countersink 13b for receiving the jig 20. In addition,
As will be described later, the hoop material 17 is used to form the mold half 1 such that the pipe end is separated from the molding end surface by a predetermined distance.
2, 13 are fitted. A jig 20 coaxially fitted into the through hole 12a of the mold half 12 serving as a receiving mold has a head 2 at its tip.
0a and a flange portion 20b are formed, and these are selectively engaged with and disengaged from the mold half 13 serving as a pressing die and the floating ring 19. In the case of the embodiment, the diameter of the flange 20b is substantially equal to the diameter of the countersunk hole 13b, and the thickness of the flange 20b is substantially equal to the depth of the countersunk hole 13b. The diameter of the body 20c of the jig 20 is determined by the head 20a and the flange 2
0b is an intermediate size between the respective diameters.

The floating ring 19 has an outer diameter that is the same as the inner diameter of the ring formed body 18.
0b has a stepped engagement hole 19a which engages and disengages. The engagement hole 19a shown in the embodiment is composed of a large diameter portion with which the flange portion 20b engages and a small diameter portion with which the flange portion 20b is locked. The diameter of the large diameter portion which regulates the jig 20 in the radial direction is The depth up to the small engaging portion that regulates the jig 20 in the axial direction, that is, the length of the large diameter portion is substantially equal to the thickness of the flange portion 20b. The floating ring 19 is a flange 2 of the jig 20.
The movement in the radial direction and the axial direction is restricted or released in accordance with the engagement and disengagement of 0b. However, the width thereof is set so that the jig 20 can be freely moved in the radial direction when the jig 20 is released. It is only slightly smaller than the width of fifteen.

The roller 16 has a width obtained by subtracting twice the thickness of the hoop material 17 from the width of the forming groove 15.
In a state where the flange 20b of the jig 20 is engaged with the mold half 13, the hoop material 17 is pressed while rotating in the reverse direction relative to the mold 14, and the floating ring 19 is rotated.
The ring formed body 18 having the same inner diameter as the outer diameter is roll-formed.

The turning tool 21 is a cutting tool for metal cutting. The turning tool 21 is disposed opposite to the outer periphery of the ring formed body 18 in place of the roller 16 after the roll forming is completed, and the ring formed body 18 is rotated together with the forming die 14. Translated to the axis,
The outer shape of the ring formed body 18 is turned by the cutting edge. However, during turning, the flange 20b of the jig 20 is engaged with the floating ring 19 instead of in the mold half 13, and the floating ring 19 is
The movement is restricted in the radial and axial directions.

In forming the ring molded body 18, first, as shown in FIG. 1A, the mold half 13 serving as a pressing mold is separated from the mold half 12 serving as a receiving mold. The floating ring 19 is engaged with the jig 20. Next, the groove 15 is covered so that the pair of mold halves 12 and 13 are pipe-fitted, and the hoop material 7 shown in FIG. That is, the hoop material 7 is shallowly fitted and held on one mold half 12 from one end side, and then the other mold half 13 is moved close to the other end of the hoop material 7 so as to be shallowly fitted. When the mounting of the hoop material 7 is completed, as shown in FIG.
0 is driven forward, the head 20 a and the flange 20 b are engaged in the mold half 13, and the roller 16 is brought into contact with the hoop material 17.

In this way, the preparation for processing is ready, but the jig 20
Of the jig 20 is loosely fitted in the shank 20c of the jig 20, but has little play in the axial direction, and floats only in the radial direction. You will be able to move. Therefore, FIG.
As shown in (C), a roller 16 having a width smaller than the groove width of the groove 15 by twice the thickness of the hoop material 17 is pressed against the hoop material 17 while rotating in the opposite direction to the molding die 14. . Thus, the necking process starts, and the neck 18a of the ring molded body 18 is gradually formed. In the necking step, the floating ring 19 is closely fitted to the inner periphery of the neck of the hoop material 17, and the hoop material 17 is formed while being restricted from being deformed from the inside. Therefore, FIG. As shown in (1), a ring intermediate having the same diameter as the floating ring 19 is formed.

When the hoop material 17 is pressed into the forming groove portion 15 while further rotating the roller 16 as shown in FIG. 1D, the neck portion as shown in FIG. It is formed into a shape close to the final formed body having circular flanges 18b at both ends of 18a. Also in the final stage of the necking and flaring process, since the molding is performed while the floating ring 19 is closely fitted to the inner periphery of the neck of the ring molded body 18 since the start of the necking process, the molded body ring 18 Can not be freely deformed on the side,
Molded in a state close to the design dimensions. For this reason, at the end of the process, a substantially completed ring formed body 19 shown in FIG. 2D is obtained, and after that, only the turning process for finishing the outer dimensions is left.

In turning, first, the jig 20 is retracted and engaged with the floating ring 19, and movement of the floating ring 19 is restricted in the radial direction and the axial direction. Thus, the ring molded body 18 is coaxially fixed to the jig 20, that is, the mold half 12 via the floating ring 19, and the preparation for the turning process is completed. Therefore, FIG.
The roller 16 is moved to turn the turning tool 21 as shown in FIG.
Is set at the processing position, and turning is performed while rotating the combination mold 14. Flange 18 of ring molded body 18
b is turned by the cutting edge of the turning tool 21 and processed to a required size, and finally, the ring formed body 18 shown in FIG. 2E is obtained. In addition, the ring compact 1 during the turning process
Since 8 is firmly held from both sides by a pair of mold halves 12 and 13 and the inner peripheral side is supported by a floating ring 19, extremely accurate turning can be performed.

As shown in FIG. 1 (F), the ring formed body 18 that has been turned can be easily removed from the formed groove 15 by separating the pressing mold half 13 as shown in FIG. However, since the ring molded body 18 is removed from the molding groove 15 for the first time when the turning is completed,
As a matter of course, there is no need to transfer to the location of the turning machine at the stage of finishing the roll forming as in the past, and turning can be performed at the same place following roll forming, so processing It is free from dimensional deviation due to deformation and unnecessary man-hours.

As described above, according to the roll forming and turning apparatus 11, the ring formed body 18 requiring dimensional accuracy such as a wear-resistant ring of a piston for a diesel engine is formed with the width of the forming groove portion 15 and the outside of the floating ring 19. Roll forming can be accurately performed in accordance with the diameter, and turning processing can be performed on the spot following the roll forming to finish the outer shape to a required size. Also, the ring molded body 1
By preparing a plurality of sets of the mold halves 12 and 13 and the floating ring 19 according to the molding shape of 8, any ring molded body 18 having a different shape can be freely molded.

[0023]

As described above, according to the present invention,
A hoop in which a floating ring having the same outer diameter as the inner diameter of the ring molded body is loosely fitted into the molding groove of the combination molding die composed of a pair of molding halves, and covers the molding groove and is fitted to the combination molding die. The material is pressed with a roller having a width smaller than the groove width of the forming groove portion and pressed while rotating in the opposite direction relative to the forming die, so that a roll is formed on the ring formed body having the same inner diameter as the outer diameter of the floating ring. The jig which had been separated from the floating ring during roll forming and then engaged with the floating ring, and the ring formed body was coaxially fixed to the combination forming die via the floating ring, and the external shape of the required dimensions When the roller is pressed while deforming the cylindrical material along the inner wall of the molding groove, the cylindrical material is In the process of molding to the final shape of the ring molded body, the floating ring fits tightly on the inner periphery of the ring molded body and regulates the neck of the ring molded body to the outer shape of the floating ring. It is possible to mold the material to be formed into a desired shape with high precision while regulating the material to be sandwiched between the flanges by the end surface of the flange by the inner wall of the groove and the inner peripheral surface of the neck by the outer peripheral surface of the floating ring. In addition, after the roll forming is completed, the floating ring can be combined and fixed to the forming die by simply moving the jig, so that turning can be performed without transferring the ring formed body to a turning machine etc. High-precision turning without deformation due to deformation is possible with a small number of man-hours. An excellent effect such as can be formed efficiently rings molded dimensional accuracy is required as a ring.

In addition, according to the present invention, the combination mold is constituted by a receiving die and a pressing die which are coaxially opposed to each other at the molding end faces, and are provided so as to be able to approach and separate from each other with a molding groove therebetween. The cylindrical material is mounted with the mold separated, and the pressing die is brought close to the receiving die to a predetermined distance, so that a forming groove corresponding to the width of the ring molded body is formed between the receiving die and the pressing die. Thus, there is an effect that the ring molded body can be accurately turned while the receiving die and the pressing die are coaxially and integrally rotated.

Further, the floating ring has a stepped engagement hole for engaging with the jig, and is positioned in the radial direction and the axial direction when the jig is engaged with the stepped engagement hole. With this configuration, the floating ring, which was loosely fitted in the forming groove during roll forming, can be accurately coaxially fixed to one mold half by the action of the jig during turning. With the movement and the replacement of the roller with the turning tool, effects such as easy transition from roll forming to turning can be obtained.

Furthermore, a jig is slidably disposed coaxially in one of the molding halves, and is selectively detachable from the floating ring or the other molding half. It is configured to engage with the half body and engage with the floating ring during turning, so that in a roll forming, a pair of mold halves are made coaxial with a jig, and during turning, the jig is floating ring. By using a jig common to both roll forming and turning, it is possible to maintain good roll forming accuracy and turning accuracy, such as coaxially fixing the ring formed body to one mold half via It has effects such as being able to do.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing a forming step by a roll forming turning apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in each forming step of a ring formed body formed by the roll forming turning apparatus shown in FIG. 1;

FIG. 3 is a longitudinal sectional view of a main part showing a forming step by a conventional roll forming apparatus.

FIG. 4 is a perspective view showing a state at each forming stage of a ring formed body formed by a conventional roll forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Roll forming and turning apparatus 12, 13 Mold half 14 Combination mold 15 Mold groove 16 Roller 17 Hoop material 18 Ring molded body 19 Floating ring 20 Jig 21 Turning tool

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code FI F16J 9/00 F16J 9/00 A (56) References JP-A-6-210383 (JP, A) JP-A-54-128961 ( JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B21D 53/16 B21D 53/84

Claims (4)

(57) [Claims] 1. A cylindrical material which is formed of a pair of mold halves forming a molding groove and is to be processed into a ring molded body having a cylindrical neck and circular flanges at both ends of the neck, And a floating ring having the same outer diameter as the inner diameter of the ring molded body, and a floating ring loosely fitted in the molding groove, and the width of the molding groove, The tubular material having a width obtained by subtracting twice the thickness of the shaped material and being fitted and mounted in the combination mold is pressed and roll-formed while rotating in the opposite direction relative to the combination mold. A roller, a jig that is engaged with the floating ring after the roller molding, and coaxially fixes the ring molded body to the combination molding die via the floating ring, and the jig that is coaxially fixed to the combination molding die. A turning tool for turning a ring formed body and finishing the outer shape to a required size. 2. The combination molding die according to claim 1, wherein the molding die comprises a receiving die and a pressing die which are coaxially opposed to each other at the molding end faces, and are provided so as to be able to approach and separate from each other via a molding groove. Roll forming turning equipment. 3. The floating ring has a stepped engagement hole that engages with the jig, and when the jig is engaged with the stepped engagement hole, the floating ring moves in a radial direction and an axial direction. 2. The roll forming and turning apparatus according to claim 1, wherein the apparatus is positioned. 4. The jig is slidably disposed coaxially within the one molding half, and is selectively engageable with the floating ring or the other molding half. 2. The roll forming and turning apparatus according to claim 1, wherein the apparatus engages with the other mold half and engages with the floating ring during turning.