JPH1141879A - Method and apparatus for press molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method and an apparatus in which an object to be molded is inserted easily even when the cylindricality of the object to be molded is bad, by a method wherein pressure is transmitted to the object to be molded via a block and an upper-mold die, the object is inserted between a punch and a lower-mold die, and a protrusion part is formed on the peripheral wall of the object. SOLUTION: A cylinder block 3 as a block driving mechanism is fixed to an upper-mold plate 2 while a block 4 faces an upper-mold die 5. Then, a cylindrical object 12 to be molded is inserted between the upper-mold die 5 and a lower-mold upper-part die 6. Then, a sensor 6b confirms that the lower end of the object 12 is situated at a step 6a, and the upper mold plate 2 is lowered. In addition, a cam 7 is lowered, a protrusion part is formed on the peripheral wall of the object 12 to be molded, by the inside molding part 9a of a lower- mold die body 9 and by the outside molding part 8b of a punch 8. As a result, it is possible to prevent the object 12 and a molding apparatus from being damaged when the object 12 is set defectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press forming method and a press forming apparatus for forming a plurality of inwardly projecting portions on a peripheral wall of a cylindrical forming object.

[0002]

2. Description of the Related Art Conventionally, there is a motor frame as a rotary electric machine as shown in FIG. The frame 1 is cylindrical and has a plurality of inward protrusions 11 on the peripheral wall. When the frame 1 having such a shape is formed, the cylindrical workpiece 12 shown in FIG. 11 is formed using the following press molding apparatus.

A lower plate 23 has a punch holder 24
A circular concave portion is formed in the center of the punch holder 24, and six guide grooves (not shown) are formed in the radial direction from the inner surface of the concave portion. A substantially cylindrical lower die 29 is mounted concentrically with the concave portion, and an inner forming portion 26 is formed at six locations on the outer peripheral surface of the lower die 29 so as to face the guide grooves. Is formed. In this case, the lower die 29 is a lower die body 29a.
And an upper plate portion 29b which is detachably attached to an upper portion of the lower die portion 29. The inner forming portion 26 is vertically elongated except for the upper and lower end portions of the lower die 29. .

In the lower die plate 23, a punch 28 is provided in each guide groove around the lower die 29 so as to be movable toward and away from the lower die 29. I have. An inclined surface 28a having an angle α is formed on the outer surface of the punch 28, and an outer molded portion 28b is formed on the inner surface. The outer forming portion 28b faces the inner forming portion 26 of the lower die 29.
Each punch 28 is moved by the tension spring 25 to the lower die 2.
9 is always urged to move in the direction away from 9. The lower die plate 23 including the punch holder 24, the lower die 29, the punch 28, and the like is adapted to be mounted on a lower base of a press (not shown).

[0005] On the other hand, a plurality of cams 27 are mounted on the upper die plate 22 in such a manner as to be arranged in a circle at equal positions, and each of the cams 27 is located above each punch 28. The cam 27 has a wedge shape with a slope 27a having an angle α formed on the inner surface thereof. The upper die plate 22 is attached to an upper elevating base of a press (not shown).

[0006]

When the inwardly protruding portion 11 is formed on the cylindrical molded object 12 using such a conventional molding apparatus, when the cylindricality of the molded object 12 is poor. When the workpiece 12 is set at a predetermined position of the inner molding portion 26 of the lower die 29, the workpiece 12 may fall down due to a slight displacement of the set position, and the workpiece 12 and the molding apparatus may be damaged. It can also cause. In particular, when a workpiece 12 is automatically set by using a robot, a problem arises.

The present invention has been made in view of the above circumstances, and is intended to reliably and safely insert a molded object into a molding apparatus by using a pressing force even if the molded object has poor cylindricity. It is an object of the present invention to provide a method and a molding apparatus capable of performing the above.

[0008]

According to the present invention, there is provided a press-forming method for forming a plurality of inwardly projecting portions on a peripheral wall of a cylindrically-shaped object. A lower die body having an inner forming portion for forming a portion is arranged, and a punch having an outer forming portion for forming the protrusion is provided near and away from the lower die body around the object to be formed. The punch is moved in the direction of the lower die main body by lowering the wedge-shaped cam from above the punch, and the molded object is pressed between the punch and the lower die main body. In the method of forming a protrusion, an upper die is disposed on a head of a molded object via a block inserted removably between an upper die plate to which the cam is mounted, and The bottom where the molded object is inserted An upper die is arranged, and the pressing force from the upper die plate is transmitted to the molding held by the upper die and the lower die upper die via a block and an upper die, thereby molding the molding. Insert between the punch and the lower die body,
A projection is formed on the peripheral wall of the molded object.

According to such a molding method, since four blocks are inserted between the upper die plate and the upper die at substantially 90-degree intervals in the circumferential direction, the pressing force from the upper die plate is reduced. , Is substantially uniformly transmitted to the object held between the upper die and the upper plate via the upper die, and the object is smoothly inserted into the outer periphery of the lower die body. Therefore, the insertion of the molded object into the lower die body does not require a large force by human power, and the insertability is improved even when the cylindricity of the molded object is poor.

[0010] A second aspect of the present invention is a press molding method in which a sensor detects whether or not the bottom portion of the molded object is inserted in the lower die upper die into which the molded object is inserted. According to this molding method, the lower end of the molded object inserted into the step of the upper plate portion is confirmed to be inserted into the step by a total of four sensors embedded in the circumferential direction of the step, so that the protrusion is formed. Since the inclination of the previous molding can be checked and the upper die can be smoothly inserted into the molding, the projection can be formed normally without falling down of the molding. As a result, the press machine starts processing only when it is confirmed by the four sensors that the molded object has been inserted into the step of the upper plate portion. The device can be prevented from being damaged.

According to a third aspect of the present invention, a lower mold plate attached to a lower base of a press machine for forming a plurality of inwardly projecting portions on a peripheral wall of a cylindrical workpiece; A lower die main body fixed to the outer peripheral surface and having an inner molded portion for forming the projection on the outer peripheral surface, and capable of approaching and separating from the lower die main body around the outer periphery of the lower die main body in the lower die plate. A punch provided with an outer molded portion for forming the protrusion, an upper plate attached to an upper elevating base of the press, and an upper elevating base attached to the upper plate so as to be located above the punch A wedge-shaped cam for moving the punch in the direction of the lower die body with the lowering of the die and pressing a cylindrical workpiece with the lower die body. A lower cylindrical upper die placed on the lower die main body and having a step on the inner periphery; and An upper die having a space formed between the upper die and the upper die and a block provided between the cams and provided at the end in the space between the upper die and the lower upper die are removably moved and disposed on the upper die plate. And a plurality of block drive mechanisms provided. With this configuration, the same operation and effect as those described in the first aspect can be obtained.

According to a fourth aspect of the present invention, there is provided a press forming apparatus provided with a sensor for detecting whether or not a bottom portion of a workpiece is inserted at a step provided on an inner periphery of the lower die upper die. With this configuration, the same operation and effect as those described in the second aspect can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
8 and FIGS. 10 and 11, the same components as those of the related art will be described using the same reference numerals. First, the frame of a motor as a rotating electric machine is as shown in FIG. The frame 1 is cylindrical and has a plurality of inward protrusions 11 on the peripheral wall. When the frame 1 having such a shape is formed, the cylindrical workpiece 12 shown in FIG. 11 is formed using the following press molding apparatus.

In FIG. 1, a punch holder 14 is provided on the lower die plate 13, and a circular recess 16 is formed in the center of the punch holder 14 as shown in FIG. 8 guide grooves 17 are formed in the radial direction. A lower die body 9 having a step 9b is attached to the recess 16 at the lower part of the outer periphery thereof, which is substantially concentric with the recess, and the guide groove is formed at eight places on the outer peripheral surface of the lower die body 9. An inner molded portion 9a is formed so as to face 17. On the upper part of the lower die body 9 and the punch 8 described below, a cylindrical lower die upper die 6 having a step 6a on its inner periphery is placed.
“a” is formed vertically long except for a step 9 b at the lower part of the outer periphery of the lower die body 9. A total of four sensors 6b are buried in the side surface of the step 6a at intervals of approximately 90 degrees in the circumferential direction.

In the lower die plate 13, a punch 8 is provided in each of the guide 17 grooves around the lower die body 9 so as to be movable toward and away from the lower die body 9. Is provided. An inclined surface 8a having an angle α is formed on the outer surface of the punch 8, and an outer molded portion 8b is formed on the inner surface. The outer molded portion 8b faces the inner molded portion 9a of the lower die body 9.
Each punch 8 is constantly urged by a tension spring 15 to move away from the lower die body 9. The lower die plate 13 including the punch holder 14, the lower die body 9, the punch 8, and the like is attached to a lower base of a press (not shown).

On the other hand, as shown in FIG. 2, a plurality of cams 7 are mounted on the upper die plate 2 in the circumferential direction, and each of the cams 7 is located above each of the punches 8. . The cam 7 has a wedge shape with a slope 7a having an angle α formed on the inner surface thereof. A substantially cylindrical upper die 5 having a plurality of steps 5a, 5b on the outer periphery is provided at a center position of the upper plate 2 to which the cam 7 is attached.
Is attached to the lower die upper die 6 with a space provided therebetween via the hanging member 5c. Further, a cylinder 5 which is a block driving mechanism having a block 4 at the tip is fixed to the upper plate 2 while the block 4 is positioned between the cams 7 with the block 4 facing the upper die 5. In this case, four are arranged at substantially 90 degree intervals. Such upper plate 2
Is mounted on an upper elevating base of a press (not shown).

Next, a method of forming an inward projection on a cylindrical object using the press forming apparatus thus formed will be described. First, the upper mold plate 2 and the lower mold plate 13 are moved up and down to provide a space, and the cylindrical molded object 12 is inserted between the upper mold die 5 and the lower mold upper die 6 (in the case of a robot, This is performed by gripping the upper part of the outer periphery of the molded object 12 with the arm). Then, the lower end of the molded object 12 is fitted into the step 6a of the lower die upper die 6, and the molded object 1 is formed by a total of four sensors 6b buried at intervals of approximately 90 degrees in the circumferential direction.
After confirming that the lower end of 2 is at the step 6a, the upper mold plate 2 is lowered to fit the step 5a of the upper die 5 into the upper end of the molded object 12 (see FIG. 3). In this state, the cylinder 3 is driven and the block 4 is inserted between the upper die plate 2 and the upper die 5 at an interval of approximately 90 degrees in the circumferential direction. When the upper die plate 2 is further lowered, the blocks 4 and There is no gap between the mold plate 2 and the upper die 5, and the pressing force from the upper mold plate 2 causes the lower end of the molded object 12 to pass through the inner diameter of the upper plate portion 6 and the outer diameter of the step 9 b at the lower periphery of the lower die body 9 Leads to.
Then, the sensor 13a embedded in the lower mold plate 13 to which the lower end of the molded object 12 abuts operates to move the molded object 12 to the projection 1
1. It is confirmed that it is at a predetermined position before molding.

Next, the cylinder 3 is driven so that the block 4 is retracted from between the upper die plate 2 and the upper die 5, and then the upper die plate 2 is lowered, so that the slope 7a of the cam 7 and the slope 8a of the punch 8 are lowered. Contact. When the cam 7 further descends,
The punch 8 moves toward the lower die body 9 against the spring force of the spring 15. As a result, the molded object 12 is pressed between the inner molded portion 9a of the lower die body 9 and the outer molded portion 8b of the punch 8, and the projection 11 is formed. When the upper lifting base of the press machine is raised, the cam 7 and the upper die 5
As a result, the punch 8 moves in a direction away from the lower die body 9 by the spring force of the spring 15 (returns to the original position). Thereafter, the upper plate 6 on the punch 8 is removed, and the molded object, that is, the motor frame 1 shown in FIG. 11 is taken out. The projection 11 is formed on this.

As described above, according to the present embodiment, the lower end of the molded object 12 inserted into the step 6a of the lower die upper die 6 is connected to a total of four sensors 6b embedded in the circumferential direction of the step 6a.
Since the insertion into the step 6a is confirmed, the inclination of the molding 12 before molding the projection 11 can be checked, and the insertion of the upper die 5 into the molding 12 can be performed smoothly.
The normal projection 11 can be formed without the 2 falling down. As a result, the lower die 6
The press machine starts processing only when it is confirmed that the molding object 12 has been inserted into the step 6 a of the molding object 1.
It is possible to prevent the molding object 12 and the molding apparatus from being damaged due to the setting failure of 2.

Further, since four blocks 4 are inserted between the upper die plate 2 and the upper die 5 at intervals of approximately 90 degrees in the circumferential direction, the pressing force from the upper die plate 2 is reduced. Via the upper die 6 and the lower die upper die 6, and the material 12 is smoothly inserted into the outer periphery of the lower die body 9. Therefore, the insertion of the molded object 12 into the lower die body 9 does not require a large force by human power, and the insertability is improved even when the cylindricality of the molded object 12 is poor.

[0021]

As described above, according to the molding method of the present invention, four blocks are inserted between the upper die plate and the upper die at approximately 90-degree intervals in the circumferential direction. Pressure from the upper die is transmitted to the molding held between the upper die and the upper plate through the block and the upper die.
The object to be molded is smoothly inserted into the outer periphery of the lower die body. Therefore, the insertion of the molded object into the lower die body does not require a large force by human power, and the insertability is improved even when the cylindricity of the molded object is poor.

In the second aspect, the lower end of the object inserted into the step of the upper plate portion is confirmed to be inserted into the step by a total of four sensors embedded in the circumferential direction of the step. It is possible to check the inclination of the molding before the projection is formed, and to smoothly insert the upper die into the molding, so that the projection can be formed normally without the molding falling. As a result, the press machine starts processing only when it is confirmed by the four sensors that the molded object has been inserted into the step of the upper plate portion. The device can be prevented from being damaged. Claims 3 and 4 have the same functions and effects as those described in Claims 1 and 2.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a molding apparatus showing one embodiment of the present invention;

FIG. 2 is a plan view as viewed from the lower surface of an upper mold plate,

FIG. 3 is a longitudinal sectional front view for explaining the operation of FIG. 1;

FIG. 4 is a plan view for explaining the operation of FIG. 2;

FIG. 5 is a longitudinal sectional front view for explaining the operation of FIG. 1,

FIG. 6 is a longitudinal sectional front view for explaining the operation of FIG. 1,

FIG. 7 is a cross-sectional plan view of the lower die body;

8 is a cross-sectional plan view for explaining the operation of FIG. 7,

FIG. 9 is a diagram corresponding to FIG.

FIG. 10 is a perspective view of a motor frame,

FIG. 11 is a perspective view of a molded object.

[Explanation of symbols]

1… frame, 2… upper plate,
3 ... Block drive mechanism (cylinder), 4 ... Block,
5. Upper die, 5a, 5b, 6a,
9b: Step, 5c: Hanging tool, 6: Lower die upper die,
6b: sensor, 7: cam,
7a, 8a: slope, 8: punch,
8b: outside molding part, 9: lower die body,
9a: inside molding part, 11: projection part,
12: molded object, 13: lower mold plate,
14: punch holder, 15: tension spring,
16: recess, 17: guide groove.

Claims (4)

[Claims] 1. A lower die having a plurality of inwardly projecting portions formed on a peripheral wall of a cylindrical molded object, the lower die having an inner molded portion for forming the projecting portion inside the molded object. Along with disposing the main body, a punch having an outer molded portion for forming the protrusion is disposed around the outer periphery of the object so as to be able to approach and separate from the lower die body, and forms a wedge shape from above the punch. By lowering the cam, the punch is moved in the direction of the lower die body, and the molded object is pressed between the punch and the lower die body to form a projection. The upper die is arranged on the head via a block inserted removably between the upper die plate on which the cam is mounted, and the molding is inserted into the bottom of the molding. Place lower die upper die, press force from upper die plate Through the block and the upper die to the molded object held by the upper die and the lower die, and the molded object is inserted between the punch and the lower die main body. A press molding method, wherein a projection is formed on a peripheral wall of an object. 2. The press-forming method according to claim 1, wherein the lower die upper die into which the object is inserted detects whether or not the bottom of the object is inserted by a sensor. 3. A lower mold plate attached to a lower base of a press for forming a plurality of inwardly projecting portions on a peripheral wall of a cylindrical forming object, and an outer periphery fixed to the lower mold plate. A lower die body having an inner molded portion for forming the protrusion on a surface thereof; and a protrusion provided on an outer periphery of the lower die plate in the lower die plate so as to be able to approach and separate from the lower die body. A punch having an outer forming portion for forming a portion, an upper die plate attached to the upper elevating base of the press machine, and attached to the upper die plate so as to be located above the punch, as the upper elevating base descends A wedge-shaped cam that moves the punch in the direction of the lower die body and presses the cylindrical workpiece with the lower die body, wherein the punch and the lower die body Up A short cylindrical lower die having a step on the inner periphery, which is placed on the upper die, and a space between the upper die plates is formed on the upper die via a suspending tool located on the lower die. The upper die provided, and a plurality of blocks disposed between the cams and provided at the tip in the space between the upper die and the lower die upper die are removably moved and disposed on the upper die plate. A press forming apparatus comprising a block drive mechanism. 4. The press-forming apparatus according to claim 3, wherein a sensor for detecting whether or not the bottom of the object is inserted is provided at a step provided on an inner periphery of the lower die upper die.