JPH0330480B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a punch adjusting device in a die set for powder molding.

[Conventional technology]

FIG. 4 shows a conventional die set for powder molding. This die set has cavity 2 of die 1.
A plurality of lower punches consisting of a combination of a fixed lower punch 4 and a floating lower punch 5 are provided around the core rod 3 inserted inside, and the fixed lower punch 4 is supported by the fixed plate 6, and the floating lower punch 5 is held in a holder. 7. This includes a structure in which the lower ram 11 is supported via a lifting pin 8, a pressing spring 9, and a yoke plate 10.

In the above-mentioned die set, the powder filled in the cavity 2 is compressed by the upper punch 12, and then the die plate 13 and the floating lower punch 5 are lowered to perform die cutting.

[Problem that the invention seeks to solve]

In the above die set, the operating amount of the lower floating punch 5 is adjusted by operating the adjustment nut 14 which is screwed to the lifting pin 8 and engaged with the lower surface of the fixed plate 6. The adjustment of the supporting force takes place by means of another adjusting nut 15 which is screwed onto the same lifting pin 8 and which engages the pressure spring 9.

However, the above-mentioned adjustment mechanism is such that when one adjustment nut 14 is operated, the adjustment amount of the other adjustment nut 15 is affected, that is, the operation amount of the lower punch and the adjustment of the supporting force are mutually related. Therefore, it is necessary to operate both nuts 14 and 15, respectively, and there is a problem in that adjustment requires a long time.

Furthermore, since each lifting pin 8 is provided at a position eccentric from the center axis of the lower floating punch 5, when adjusting the operating amount, the parallelism of the lower floating punch 5 is likely to be lost, and the die 1 and the lower floating punch 5 may be damaged.

Furthermore, since the installation space of the pressing spring 9 is limited, the absolute supporting force of the lower floating punch 5 is insufficient, and because adjustment is difficult, it is difficult to determine the lowering timing of the lower floating punch 5 during molding. This may cause molding defects.

Therefore, an object of the present invention is to provide a lower punch adjusting device that solves the above problems.

[Means for solving problems]

A fixing plate is provided between the die plate and the yoke plate, and the die plate and the yoke plate are integrally connected by a support, and the lifting pin of the lower punch inserted into the die of the die plate is passed through the fixing plate and placed below it. In the lower punch adjusting device of a die set for powder molding, which protrudes from the top and is interposed between the protruding portion and the yoke plate, an adjusting disk is fixed to the lower end of the lifting pin, and a fixing plate is fixed to the outer periphery of the adjusting disk. A first adjustment ring having an outer diameter that can be engaged with the lower surface is screwed into the core holder, and a second adjustment ring is screwed into the outer periphery of the core holder screwed into the center of the yoke plate.
The upper surface of the second adjustment ring and the lower surface of the first adjustment ring are abutted against each other.

[Effect]

When the first adjustment ring is rotated while being separated from the fixed plate and the second adjustment ring, the height of its lower surface changes, so the lower ram is then driven and the second
When the adjustment ring is applied to the first adjustment ring and the first adjustment ring is further applied to the fixed plate, the height of the lower punch with respect to the fixed plate (specifically, the distance between the lower punch holder 34 and the stopper 36) changes. As a result, the amount of operation of the lower punch during compression is adjusted. Furthermore, when the second adjustment ring is rotated, the height of its upper end surface changes, so the height of the lower punch relative to the die plate, that is, the depth of the cavity changes. As a result, the powder filling height is adjusted. Note that the lower punch is supported by the lower ram during compression.

[Example] The schematic structure of the die set shown in FIG.
2. Die plate 23 and upper punch plate 2
4, the fixing plate 22 is connected to the press body 25.
At the same time, the yoke plate 21 is supported by a lower ram 26 of the press, and an upper ram (not shown) is connected to the upper punch plate 24.

The fixed plate 22 has a plurality of support columns 2.
The yoke plate 21 and the die plate 23 are connected by these pillars 26', and the die plate 23 is driven by the lower ram 26.

A die 27 is fixed to the center of the die plate 23, and an upper punch 29 attached to the upper punch plate 24 faces above the cavity 28 of the die 27. Further, a guide rod 30 of the upper punch plate 24 passes through the die plate 23 in a freely slidable manner.

A core rod 31 passes through the center of the cavity 28 of the die 27, and around the core rod 31 there is a fixed lower punch 32 on the inside and a floating lower punch 3 on the outside.
3 are arranged concentrically.

A holder 34 of the floating lower punch 33 is arranged between the die plate 23 and the fixed plate 22, the fixed lower punch 32 passes through this holder 34, and its lower end is supported by the fixed plate 22.

The four lifting pins 35 connected to the holder 34 slideably pass through the fixing plate 22 and protrude below.

Further, on the upper surface of the fixed plate 22, stoppers 36 are slidably provided at two centrally symmetrical locations. The stopper 36 is open at the top and bottom, and a roller 37 is attached to the open portion. Further, the stopper 36 is urged toward the center by a spring 38 attached to the fixed plate 22, and in a normal state, its inner end engages with the lifting pin 35 and is located below the holder 34. A wedge 39 fixed to the lower surface of the die plate 22 faces above the stopper 36.

An adjustment disc 40 is attached to the downwardly projecting end of the lifting pin 35. A first adjustment ring 41 is screwed onto the outer periphery of the adjustment disc 40.

Further, the core rod 31 passes through the center of the adjustment disc 40, and its lower end is connected to the core holder 42.
The core holder 42 is screw-fitted to the yoke plate 21. When the core holder 42 is rotated, the vertical height of the core rod 31 is adjusted.

A second adjustment ring 43 is screwed onto the outer periphery of the core holder 42, and the second adjustment ring 43
The upper surface and the lower surface of the first adjustment ring 41 abut against each other so as to be able to come into contact with and separate from each other.

Details of the adjustment disk 40 and first adjustment ring 41 are as shown in FIGS. 2 and 3.
That is, the adjustment disc 40 has a core rod 31 in the center.
A through hole 44 is formed, and a mounting hole 45 for a lifting pin 35 is formed around the through hole 44. Threaded portions 46 are formed at two centrally symmetrical locations on the outer peripheral surface of the adjustment disc 40, and a recess 47 is formed between each threaded portion 46.

The first adjustment ring 41 has the above-mentioned threaded portion 4 on the inner peripheral surface.
A female screw 48 is formed to be screwed into the lock screw 6, and screw holes 50 for inserting a lock screw 49 are provided at required intervals. The intervals between the screw holes 50 are determined so that at least one screw hole 50 can face each recess 47 regardless of the rotational position of the first adjustment ring 41 with respect to the adjustment disc 40. It is being

Note that the same locking mechanism as described above is also employed at the screw-fitting portion between the second adjustment ring 43 and the core holder 42.

The structure of the embodiment is as described above, and its operation will be explained next.

When the second adjustment ring 43 is rotated before driving the lower ram 26, the second adjustment ring 43 rotates to the first position.
The stroke changes until it hits the adjustment ring 41, and the fixed plate 22 of the die plate 23
As a result of adjusting the height relative to the cavity 28
The depth of the powder, that is, the filling height of the powder is adjusted.

In addition, the first adjustment ring 41 is attached to the fixing plate 22.
When the first adjustment ring 41 is rotated in a state where it is separated from the lower surface of the ring and the upper surface of the second adjustment ring 43, the height of the lower surface changes.
The height at which the lifting pin 35 is pushed up when the adjustment ring 43 hits its lower surface changes, and the holder 34
The distance between the stopper 37 and the stopper 37, that is, the amount of operation when the floating lower punch 33 is compressed can be adjusted.

After completing the preparation work as described above, the cavity 28 is filled with molding powder, and then the upper ram is driven to insert the upper punch 29 into the cavity 28 to perform compression. The lower ram 26 is lowered in synchronization with this compression. In this case, the floating lower punch 33 descends together with the holder 34, lifting pin 35, etc. by the above-mentioned compressive force and with the ram 26 supporting the compressive force. The floating lower punch 33 descends until the holder 34 hits the stopper 36, and when it hits the stopper 36, compression is completed. At this point, the die plate 23 is slightly lowered, but the wedge 39 does not move the stopper 36. After the compression is completed, when the lower ram 26 is lowered, the die plate 23 is lowered, the collar of the molded product is cut out, and the wedge 39 is moved to the stopper 36.
37 to move it outward. At that point, the lower surface of the die plate 23 comes into contact with the shoulder portion of the holder 34 and pushes it down. Further, as the lower ram 26 descends, the core rod 31 also descends, completing the die cutting.

〔effect〕

As described above, in the lower punch adjustment device of the present invention, by operating the first adjustment ring, the height of the lower surface is changed, and when the lower ram is raised, the height of collision with the second adjustment ring is changed. Therefore, the height of the lower punch relative to the fixed plate changes, and the amount of operation of the lower punch during compression can be adjusted. Since such adjustments can be made only by operating the single first adjustment ring, the adjustments can be made in a short time and the parallelism of the lower punch can be maintained well. In addition, by operating the single second adjustment ring, the height of its upper end surface changes, so the height of the lower punch relative to the die plate, that is, the depth of the cavity, changes, reducing the powder filling height. It can be adjusted with time.

In addition, since the floating lower punch is supported by the lower ram, the supporting force is greater than that supported by a spring, and good lowering timing can be achieved without any special adjustment of the supporting force. As a result, molded products with stable quality can be obtained.

Further, the core rod can be adjusted up and down in a short time by rotating the core holder screwed into the center of the yoke plate.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of the embodiment, FIG. 2 is an exploded perspective view showing a part of the adjusting device, FIG. 3 is a lateral plan view of the same, and FIG. 4 is a longitudinal sectional front view of the conventional example. 21... Yoke plate, 22... Fixed plate, 23... Die plate, 24... Upper punch plate, 27... Die, 28... Cavity, 2
9... Upper punch, 31... Core rod, 32...
Fixed lower punch, 33...Floating lower punch, 34...
Holder, 35... Lifting pin, 40... Adjustment disc, 41... First adjustment ring, 42... Core holder, 43... Second adjustment ring, 46... Threaded portion, 47... Recess, 48 ...Female thread, 49...Lock pin, 50...Screw hole.

Claims (1)

[Claims] 1. A fixing plate is provided between the die plate and the yoke plate, the die plate and the yoke plate are integrally connected by a support, and the lifting pin of the lower punch inserted into the die of the die plate is passed through the fixing plate. In a lower punch adjusting device in a die set for powder molding that projects downward and is interposed between the projecting portion and the yoke plate, an adjusting disk is fixed to the lower end of the lifting pin and fixed to the outer periphery of the adjusting disk. A first adjustment ring having an outer diameter that can be engaged with the lower surface of the plate is screwed into place, a second adjustment ring is screwed into the outer periphery of the core holder which is screwed into the center of the yoke plate, and the second adjustment ring is A lower punch adjusting device for a die set for powder molding, characterized in that an upper surface and a lower surface of a first adjusting ring are brought into contact with each other.