JP2001259896A - Powder compaction press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder compaction press which can save the drive energy of the total press and realize the high cycle time. SOLUTION: In the powder compaction press 1, a slide 4 having an upper ram 4e is vertically moved by a toggle mechanism 3 connected to a drive cylinder 2b, and a lower ram 8 is vertically moved following the vertical movement of the slide 4 via a link mechanism 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder compacting press, and more particularly to a compacting press having a toggle mechanism and a repressing press.

[0002]

2. Description of the Related Art As a compacting press or a repressing press used as a powder compacting press, a hydraulic press in which an upper ram and a lower ram are driven by a hydraulic cylinder to perform compaction and repressing is widely used. However, it has been pointed out that such a hydraulic powder molding press requires large driving energy and has a slow cycle time as an improvement factor.

[0003]

There is a demand for a conventional hydraulic molding press having these improvements that can be driven with energy saving and can be driven in a high cycle. It is very difficult to develop such a powder molding press. That is, in the conventional hydraulic pressing press of the hydraulic type, since the hydraulic driving sources are separately required to drive the upper ram and the lower ram, at least two driving sources are required and a large driving energy is required. And had In order to reduce the total energy per powder molding press, it is only necessary to simply lower the rated capacity of each electric motor as a driving source, but then the pressure required for molding and re-pressing is sacrificed, There is a problem that the basic performance of the powder molding press that exerts a pressing force cannot be satisfied.

[0004] Also, in terms of speeding up the cycle time, there is a limit in terms of the mechanism of the hydraulic type powder molding press, and the mechanical press is superior in view of the mere increase in speed. It is also possible to do. However, the mechanical press has a complicated mechanism, and accordingly, the size of the apparatus is increased as a whole, and it is difficult to consider the cost.

As described above, the conventional powder compacting press has advantages and disadvantages, and it is difficult to reach an ideal one. However, the present inventors have proposed a powder compacting press which can save energy as much as possible and can be driven in a high cycle. As a result of various studies as to whether a press can be realized, the following new powder compacting press satisfying these requirements has been conceived.

[0006]

That is, the powder molding press provided by the present invention to achieve the object of realizing a powder molding press which can be driven in a high cycle with energy saving is provided by:
A powder forming press in which a slide having an upper ram is moved up and down by a toggle mechanism connected to a driving cylinder. The powder molding press is connected to the slide and the lower ram, and the lower part follows the up and down movement of the slide. It is characterized by having a link mechanism for moving the ram up and down.

The development of this powder compacting press was triggered by the fact that the force and speed operating characteristics of a toggle mechanism found in a mechanical press were successfully used as a mechanism for transmitting the movement of a drive cylinder to a ram in a powder compacting press. The present inventor has found out what can be done. In the powder molding press, since it is sufficient that a large force can be exerted when the object to be pressed is pressed, no force is required from the upper limit to the lower limit of the drive cylinder, and it is preferable that the speed be higher. Since a large pressing force is required in the pressurizing step starting slightly above the lower limit, it is not necessary to operate at a high speed. Since the operating characteristics of the force and the speed coincide with the operating characteristics of the force and the speed of the toggle mechanism, if this is used for a hydraulic powder molding press, powder molding can be performed in a high cycle. However, the toggle mechanism has a drawback that the pressure range is narrow and is not suitable for powder molding, but such a drawback can be improved depending on the design of the toggle link. Therefore, even if a toggle mechanism is used, a pressing force equivalent to that of a general hydraulic type powder molding press can be exerted, and a powder molding press capable of high cycle driving can be realized. Further, as a result of various studies on the point of energy saving drive, the problem has been solved by newly devising the above-described link mechanism for linking the vertical movement of the lower ram with the vertical movement of the slide.

Therefore, according to this powder molding press, since the link mechanism is connected to the slide and the lower ram and moves the lower ram up and down following the vertical movement of the slide, the lower ram is driven. A separate drive source such as a hydraulic pump is not required, and energy saving can be achieved. In addition, the slide can be moved up and down at high speed by the toggle mechanism, and the lower ram follows the slide via the link mechanism. And can move up and down at high speed, so that the cycle time can be shortened. In addition, since a drive source such as a hydraulic pump is not required for the lower ram as described above, the structure of the device around the lower ram is simplified, so that the overall device size can be reduced and the installation space can be reduced. it can.

When the above-mentioned link mechanism is applied to a repressing press, the following specific structure is obtained. That is, the link mechanism portion includes a link arm having an upper end portion rotatably connected to the slide and extending to the side of the lower ram,
A link plate rotatably connected to the bed and the link arm, and a link plate rotatably connected to the lower ram between these connection points, wherein the link plate is The lower ram and the link arm can be moved up and down in the same direction with the connection point as a pivot point.

[0010] The link mechanism portion of the above can also be applied to the molding press. In this case, the specific configuration of the link mechanism portion includes a link arm whose upper end is rotatably connected to the slide and extends to the side of the lower ram, and a link arm that rotates to the lower ram and the link arm, respectively. And a link plate rotatably connected to the bed between these connection points, wherein the link plate has a connection point to the bed as a swing fulcrum, and a lower ram. The link arms can be configured to move up and down in opposite directions.

The link mechanism of the molding press may be further provided with a lock mechanism for locking or unlocking the connection of the link plate to the lower ram. According to this lock mechanism, when the connection between the lower ram and the link plate is locked, the vertical movement of the lower ram can follow the vertical movement of the slide via the link mechanism. Conversely, unlocking the connection prevents the lower ram from interlocking with the vertical movement of the slide. Therefore, it is possible to cope with various operation modes according to a molding method such as a withdrawal operation and a floating die operation.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The powder compacting press of the present invention can be applied to various powder compacting presses such as a compacting press and a repressing press. In the present embodiment, an example in which the powder compacting press and the repressing press are used will be described. Note that members having the same function in each embodiment are denoted by the same reference numerals, and redundant description is omitted. In some cases, details of the powder molding press and its components shown in each drawing are omitted for easy understanding.

[0013] One embodiment of repressing press

1.1 Configuration of repressing press

(1) Outline of the overall configuration of the repressing press; FIG.
Is a front view of a press 1 used in the repressing press of the present example. This press 1 includes an upper mechanism 2, a toggle mechanism 3, a slide 4, and a lower mechanism 5, and four columns 6. A tool set 7 shown in FIG. 2 is removably incorporated between the slide 4 and the lower mechanism 5 so as to constitute a repressing press.

(2) Configuration of the upper mechanism section: The upper mechanism section 2 is provided with a hydraulic cylinder 2b serving as a drive source on an upper frame 2a, and this hydraulic cylinder 2b moves up and down.

(3) Configuration of Toggle Mechanism Section The toggle mechanism section 3 is provided with a first link 3a and a second link 3b, and the ends of both links 3a and 3b are rotatably connected to each other. Have been. The first link 3a is connected to a cylinder arm 2c attached to a lower end of the hydraulic cylinder 2b, and is rotatably connected to the hydraulic cylinder 2b. At the same time, the first link 3a is connected to the upper frame 2a.
Is also rotatably connected to a mounting arm 2d projecting downward. The lower end of the second link 3b is rotatably connected to a mounting arm 4b projecting upward from the upper surface 4a of the slide 4. When the hydraulic cylinder 2b moves up and down, the toggle mechanism 3 configured as described above moves the slide arm 4c in synchronization with the vertical movement of the hydraulic cylinder 2b as a result of the cylinder arm 2c interlocking with the first link 3a and the second link 3b. Will be moved up and down.

(4) Structure of the Slide The slide 4 connected to the toggle mechanism 3 is movable up and down under the guide of the column 6. The vertical movement of the slide 4 is performed by the hydraulic cylinder 2b via the toggle mechanism 3, but the stroke of the slide 4 becomes 1 with respect to the stroke 1.3 of the hydraulic cylinder 2b, and the pressing force is reduced by the toggle mechanism. The power is increased to about 12 times the output of the hydraulic cylinder 2b by the section 3. Therefore, the driving power of the hydraulic cylinder 2b is about 1 compared to a hydraulic press having the same capacity.
It is about / 3, and can be driven with energy saving. An adjusting mechanism 4d for finely adjusting the pressing stroke is provided on the bottom surface 4c of the slide 4. In the press 1, the drive of the hydraulic cylinder 2a is transmitted to the slide 4 using the toggle mechanism 3, so that the pressing range is narrowed to a narrow range. Therefore, the pressure point (the lower limit of the upper punch 7f) can be finely adjusted by the adjusting mechanism 4d so that the optimum pressure can be obtained.

(5) Configuration of Tool Set Here, the tool set 7 for re-pressing to be installed between the slide 4 and the lower mechanism 5 will be described. The tool set 7 includes an upper punch plate 7a, a die plate 7b, a base plate 7
c is configured to be supported by the guide post 7d. A ram hold 7e is provided on the upper surface of the upper punch plate 7a. By connecting the ram hold 7e to the upper ram 4e of the slide 4, the upper punch plate 7a and the upper punch 7f fixed to the bottom surface of the slide 4 are moved. It is movable up and down following the up and down movement of. A lower punch 7g is attached to the base plate 7c so as to be movable up and down. The lower punch 7g receives a load applied to the work at its lower limit position, and receives an upward movement of a lower ram 8 provided in the lower mechanism portion 5 to position the upper surface of the die plate 7b. The workpiece in the die cavity 7h is knocked out and removed by the feeder 7i. In this example, since the die is fixed, the die plate 7b does not move up and down, and the work is set in the die cavity 7h by the linear feeder 7i.

(6) Configuration of Link Mechanism Section The link mechanism section 9 shown in FIG.
1 and 1. The upper end of the link arm 10 is rotatably fixed to the bottom 4 c of the slide 4, and the lower end thereof is rotatably connected to the link plate 11. The opposite end of the link plate 11 is rotatably connected to a mounting arm 12 a projecting downward from the bottom of the bed 12. And
Assuming that the length connecting the connection center of the link arm 10 and the connection center of the mounting arm 12a is 3, the lower end of the lower ram 8 is attached to the portion of the link plate 11 where the length from the connection center of the mounting arm 12a becomes 1. It is connected so as to be rotatable. As a result of determining the connection centers with such a length relationship, the stroke amount is slide (4): lower ram.
(8) = 3: 1. The reason for this is that the stroke of the upper punch 7f requires a space for the work to be re-pressed.

1.2 Operation of repressing press

The operation of the repressing press composed of the press 1 and the tool set 7 as described above will be described with reference to FIGS. FIG. 3 is a cycle diagram of the tool set 7.

(1) Initial state; In the repressing press, in the initial state before starting the repressing step, the press 1 is in the state shown in FIG. As shown in FIG. 3, the tool set 7 has the upper punch 7f and the lower punch 7g both at the ascending limit at the time point a. At this time, the upper surface of the lower punch 7g is substantially flush with the upper surface of the die plate 7b. (See FIG. 2).
The work to be repressed is in the feeder 7i (see FIG. 2).

(2) Repressurizing step: From this initial state, the toggle mechanism 3 interlocks and lowers the slide 4 as the hydraulic cylinder 2b lowers. At the same time, the lower punch 7g starts descending in conjunction with the link mechanism 9 (FIG. 1). At this time, the lower punch 7g separates from the work and descends before the upper punch 7f contacts the work.

Then, the upper punch 7f starts a re-pressing step on the work. At this time, the lower punch 7g is descending beforehand, but slightly above the lowering limit, a stopper (not shown)
To stop descending. The work is pressed by the upper punch 7f and the lower punch 7g from the time point b to the time point c, and reaches a predetermined pressing force. At this time, the lower ram 8
Is slightly lowered, and the lower ram 8 is also lowered at the lower limit of the slide 4. In addition, the above-mentioned predetermined pressurizing force can be held as needed by drive control of the hydraulic cylinder 2b.

(3) Knockout step: After the pressurization, the slide 4 is raised via the toggle mechanism 3 with the rise of the hydraulic cylinder 2b as shown at the point c. Accordingly, the upper punch 7f starts to move up to the upper limit. After the upper punch 7f rises, the lower ram 8 rises and contacts the lower punch 7g after a slight stroke. Accordingly, the lower punch 7g is moved to the upper punch 7 as shown at the time point d.
It will be pushed up after a slight delay from the start of the rise of f. And the lower punch 7g from the time point d to the time point e
Is pushed out, the work is knocked out. e
At this point, the upper surface of the lower punch 7g is substantially flush with the upper surface of the die plate 7b, and the lower punch 7g stops there.
Then, the feeder 7i starts moving (time e), removes the work, and returns to the original position. Thus, since the repressing press returns to the home position, the above steps are repeated. After returning to the original position, the slide 4 is slightly lowered as shown by a two-dot chain line in FIG. The process may be repeated.

1.3 Effects of the Embodiment In the repressing press of this example, almost no force is required until the upper punch 7f hits the work in the die cavity 7h. Therefore, in this machining process, the faster the lowering speed of the upper punch 7f (slide 4), the more the cycle becomes higher. On the other hand, after the upper punch 7f hits the work, a maximum pressing force is required in the final pressing while gradually applying a force. Thus, this repressing process requires a greater force than speed. After the final pressurization, the work is knocked out by the lower punch 7g. The knockout force required at this time does not need to be so large, and once it starts to be released, it can be knocked out with a smaller force. Generally, the knockout force and the pressing force are about 1: 2, but as a result of the link mechanism 9 generating a force three times as high as the lifting force of the slide 4, theoretically (（) × the pressing force. (1/2) = 1/6 is sufficient, and it is possible to perform the knockout operation sufficiently with a part of the lifting force of the slide 4.

The relationship between the force and the speed in such a series of re-pressures matches the relationship between the force and the speed due to the operation of the toggle mechanism 3 of this embodiment. In other words, the toggle mechanism 3 operates at a high speed by the first link 3a and the second link 3b in the section [upper limit to slightly lower position], and in the section [lower upper position to lower limit]. Although the speed is low, it exerts the maximum pressing force. Therefore, based on the up and down movement of the upper punch 7f (slide 4) by the toggle mechanism 3, the link mechanism 9 is linked to this, and the lower punch 7g (lower ram 8) is vertically moved synchronously. According to the pressure press, a desired pressing force can be exerted in the pressurization process, and the basic press performance as a repressing press can be satisfied. In addition, since the ascending / descending stroke can be accelerated by the toggle mechanism 3, the demand for a high cycle can be satisfied. In addition to these, the lower punch 7g (lower ram 8) can be driven by the link mechanism 9, so that a separate drive source such as a hydraulic pump is not required to drive the lower ram 8, and the demand for energy saving is satisfied. Can be.

2 Embodiment of Forming Press

2.1 Configuration of Forming Press

In this embodiment, the above-described press 1 is configured as a forming press. The overall configuration of the press used in this forming press is the same as that of the press 1 of the repressing press in FIG. 1, but the configurations of the lower mechanism section 5 and the tool set 7 are different.

(1) Configuration of Lower Mechanism Section FIG. 4 is an enlarged view of a schematic configuration of the lower mechanism section 5 of the molding press of the present embodiment. Although FIG. 4 shows only the link mechanism 9 on the right side, a similar link mechanism is provided on the left side. The link mechanism 9 has a right end of the link plate 11 rotatably connected to the link arm 10 and a left end rotatably connected to the lower ram 8. The link plate 11 is rotatably connected to the bed 12 with respect to a mounting arm 12a that is rotatably mounted between the connecting portions. Therefore, the link plate 11 swings around the connection point to the mounting arm 12a as a fulcrum,
The lower ram 8 and the link arm 10 are moved up and down in opposite directions. Bottom plate 8 of lower ram 8
Reference numeral a and 13 attached to the bed are hydraulically driven auxiliary cylinders, which are used to drive up the die plate 7b (see FIG. 8 ).

(2) Configuration of Lock Mechanism Section The lower ram 8 is provided with a lock mechanism section 14. This is for locking / unlocking the connection between the lower ram 8 and the link plate 11 according to a series of molding processes. FIG.
FIG. 5 is an enlarged view of a connecting portion between the lower ram 8 and the link plate 11 shown in FIG. In FIG. 5, a guide block 8b shown in FIGS. 6 and 7 described below is not shown.

As shown in FIGS. 5 and 6, the lock mechanism 14 of the lower ram 8 includes a main body 14a and a guide plate 14.
b. The guide plate 14b is formed with a guide hole 14d for guiding the vertical movement of the lock cylinder rod 14c in the locked state. An air cylinder body 14e is attached to the opposite side of the guide plate 14b. The air cylinder body 14e includes a lock cylinder rod 14 for locking / unlocking the link plates 11 on the front side and the rear side.
c, and a storage section 14f having an internal space s for storing the base side thereof. The storage section 14f is formed with two ventilation holes 14g and 14h for sending air into the internal space s by an external air supply unit (not shown). The lock cylinder rod 14c is capable of moving forward and backward in the axial direction by sending air through the ventilation holes 14g and 14h.

(3) Lock / unlock control; where:
The lock / unlock control by the lock cylinder rod 14c will be described with reference to FIGS. FIG. 6 shows an unlocked state, and FIG.
(A). In this state, the link plate 11 on the left side in the figure and the lock portion 14j of the main body portion 14a, and the lock portion 14j on the right side in the figure and the guide plate 14b are respectively connected via the large-diameter portion 14i of the lock cylinder rod 14c. It is unlocked because it is not connected. Therefore, even if the slide 4 moves up and down and the link plate 11 (the lock cylinder rod 14c) moves up and down, the lower ram 8 does not move.

In order to shift from the unlocked state to the locked state, air is blown into the lock cylinder rod 14c by blowing air from the passage 14g in a state where the ventilation hole 14h of the storage portion 14f shown in FIG. 6 is opened. Then, the lock cylinder rod 14c is biased and moves forward in the right direction in the figure. This state is shown in FIG. At this time, the large-diameter portion 14i of the lock cylinder rod 14c is connected to both the link plate 11 on the left side in the figure and the lock portion 14j of the main body 14a, and to both the link plate 11 on the right side and the lock portion 14j of the guide plate 14b. , Respectively. Therefore, the link plate 11 and the main body portion 14a, and the link plate 11 and the guide plate 14b are locked through the large diameter portion 14i. In this locked state, when the slide 4 moves up and down and the link plate 11 (lock cylinder rod 14c) moves up and down, the lower ram 8 moves up and down following the movement.

Then, in order to return from the locked state to the unlocked state again, the internal space s may be filled with air by blowing air from the ventilation hole 14h while the ventilation hole 14g shown in FIG. 6 is opened. Then lock cylinder rod 14
6c is urged by the air pressure of the air blown into the internal space s, and retracts to the position shown in FIGS. 6 and 7A to be unlocked.

(4) Configuration of Tool Set Next, a tool set 7 for molding which is removably mounted on the press 1 of this embodiment.
Will be briefly described with reference to FIG. The tool set 7 is used for withdrawal operation or floating die operation. The upper punch plate 7a, the die plate 7b, and the base plate 7c
The structure is supported by d. Die plate 7
A rod 7j is fixed to the bottom surface of b, and the lower end is fixed to the yoke plate 7k through the insertion hole of the base plate 7c. The upper punch plate 7a is connected to the upper ram 4d of the slide 4 by a ram hold 7e provided on the upper surface of the upper punch plate 7a, and the upper punch 7f is vertically movable as the slide 4 moves up and down. Since the yoke plate 7k is connected to the lower ram 8 via the ram hold 7e, the die plate 7b is movable up and down as the lower ram 8 and the yoke plate 7k move up and down. A lower punch 7g is fixed to the base plate 7c so as not to move. A feeder 7i fills the die cavity 7h with the raw material powder by volumetric weighing by scraping.

2.2 Operation of molding press

The operation of the forming press constituted by the press 1 and the tool set 7 as described above will be described with reference to FIGS. 1, 4 to 10. FIG. 9 is a cycle diagram of the tool set 7, and FIG. 10 is an overall operation explanatory diagram including the slide 4, the lock cylinder 14c, and the lower ram 8.

Here, first, in order to facilitate understanding, FIG.
0 will be explained. FIG. 10 shows each molding process.
It shows how the slide 4, the link mechanism 5, and the lower ram 8 change. In FIG. 10, slide 4
(A) Move the (upper punch 7f) to the lock cylinder 14c.
The movement of the (link plate 11) is represented by (b), and the movement of the lower ram 8 (die plate 7b) is represented by (c), and each is represented by vertical arrows. 5D, the shape of the guide hole 14d of the guide plate 14b is displayed as a symbol representing the lower ram 8 (see FIG. 5), whereby the lower ram 8 (die plate 7b) itself moves up and down. The displacement is displayed together with the arrow (c). Also,
The double circle that moves up and down inside the guide hole 14d means the front shape of the lock cylinder rod 14c (see FIG. 5), thereby indicating the displacement of the lock cylinder rod 14c (link plate 11) in the vertical movement. ing.

(1) Home Position As described above, the press 1 of FIG. 1 and the tool set 7 of FIG. 8 are in the home position. That is, as shown at the time point a in FIG. 9 and FIG. 10A, the upper punch 7f is at the upper limit,
At this time, the upper surface of the lower punch 7g is located inside the die cavity 7h, and the upper surface receives the raw material powder.
In addition, as a method of filling the raw material powder, a suction filling in which the raw material powder is placed on the die 7m by a feeder 7i or manually and then the die plate 7b is raised and filled, and the die plate 7b is raised in advance to form a pot. After that, there is a drop filling in which the raw material powder is filled. In order to cope with any of these, the lower ram 8 is unlocked separately from the link plate 11 at this home position. Further, as shown by (d-1) in FIG. 10, the lock cylinder rod 14c is at the retreat limit.

(2) Forming Step In the next forming step, the slide 4 is lowered via the toggle mechanism 3 by the lowering of the hydraulic cylinder 2b from the time point a to the time point b. At the same time, the upper punch 7f also descends (FIGS. 9, 10).
(a)). When the slide 4 descends, the lock cylinder rod 14c connected to the link plate 10 via the link mechanism 9 ascends (arrows in FIG. 10 (b), (d-2) → (d-
3)). On the other hand, since the lower ram 8 is unlocked with the link plate 11, it remains stationary (FIG. 10 (d-2) → (d-
3)).

From time point b in FIG. 9, the upper punch 7f
m and hits the raw material powder, the upper punch 7f is used by using the auxiliary cylinder 13 in order to obtain a vertical pressing effect.
The forced lowering of the die plate 7b (lower ram 8) is started at about 1/2 of the speed (see arrows in FIGS. 9 and 10 (c), (d-
3) → (d-4)). That is, the withdrawal operation is started.
In addition to the withdrawal operation, the auxiliary cylinder 1
It is also possible to operate the floating die for applying a counter force by means of 3.

Then, in the section from the time point c to the time point d in FIG. 9, the raw material powder is compacted by the upper punch 7f and the lower punch 7g. In addition, it is also possible to control so as to maintain this pressurization as needed. At this time, the lock cylinder rod 14c has reached the ascending limit, and the lower ram 8 is located below by an amount further reduced by forced lowering or floating lowering for forming lowering (FIG. 11 (d-)).
Four)). Then, at the time point d in FIG. 9, the lock cylinder rod 14c is advanced in the manner described above to lock the connection between the lower ram 8 and the link plate 11.

(3) Knockout process: When the pressurization is completed (at the time of FIG. 9D), the upper punch 7f starts to be pulled up (arrow in FIG. 10A). Accordingly, the lock cylinder rod 14c also starts descending. Although the lower ram 8 (die plate 7b) is locked, since it has already been lowered by the lowered amount, it lowers to that position and then descends in accordance with the rise of the slide 4 to knock out the molded product (FIG. 10). (d-6) (d-7) (d-8)). Then, the upper punch 7f becomes the upper limit at the upper limit of the slide 4, and the lower ram 8 also becomes the lower limit (FIG. 9D, FIG. 10D-8). at this point,
The lock cylinder rod 14c is retracted in the manner described above to unlock the connection between the lower ram 8 and the link plate 11. Next, the molded product is taken out, and the auxiliary cylinder 13 is driven from the time point g in FIG. 9 to raise the die plate 7b (FIG. 10 (d-8) → (d-10)), and is again filled with the raw material powder (FIG. 10). 10 (d-9)). When the filling is completed at time point h in FIG. 9, the molding press repeats the above-described series of molding steps.

2.3 Effects of the Embodiment; The point that the relationship between the force and the speed in the re-pressing is the same as the relationship between the force and the speed by the toggle mechanism section 3 of the present embodiment is the same for the forming press of the present embodiment. In other words, the desired pressing force can be exerted in the pressing step, and while the basic pressing performance as a molding press is satisfied, the ascending / descending stroke can be accelerated by the toggle mechanism 3 to meet a demand for a high cycle. Can also be satisfied. In addition, since the die plate 7b (lower ram 8) can be driven in the knockout step requiring force by the link mechanism 9, a separate large driving source is not required for driving the lower ram 8, and there is a demand for energy saving. Can be satisfied. In the molding press of this example, when refilling the raw material powder after knocking out the molded product and when performing the up-down pushing effect (withdrawal operation), the die plate 7b is driven by using the auxiliary cylinder 13 having a small driving energy. Is being driven. However, since the auxiliary cylinder 13 can be operated with less driving energy than a general hydraulic press, the requirement for energy saving as a whole apparatus is still satisfied. Also, as in the forming press of this example, the lower ram 8 and the link plate 11
Is provided with a lock mechanism unit 14 that can lock / unlock the connection of the above, various operation modes according to the molding method and molding conditions, such as withdrawal operation and floating die operation, can be realized. The added value of the press can be increased.

[0048]

According to the powder molding press of the present invention, since a link mechanism is provided, there is no need for a drive source such as a separate hydraulic pump for driving the upper and lower rams as in a conventional hydraulic press. Can be used also as the drive source for the lower ram. Therefore, basically, only one drive source for the upper and lower rams is required, and even when provided for driving the lower ram, an auxiliary source having a small force is sufficient. That is, significant energy saving can be achieved for the entire press. In addition, since there is basically no need for a drive source for driving the lower ram, there is another advantage in that the entire press can be made compact and the installation space can be reduced. In addition to these effects, the present invention includes the toggle mechanism, so that the cycle time can be shortened.

Further, according to the powder molding press of the present invention having the lock mechanism, it is possible to realize various operation modes corresponding to molding methods and molding conditions such as withdrawal operation, floating die operation, and the like. It can be a press with high added value.

[Brief description of the drawings]

FIG. 1 is a front view showing a press used in a repressing press according to an embodiment of the present invention.

FIG. 2 is a front view showing a tool set for a repressing press incorporated in the press of FIG. 1;

3 is a cycle diagram of a repressing press incorporating the tool set of FIG. 2 into the press of FIG. 1;

FIG. 4 is a front view showing a lower mechanism of the forming press according to the embodiment of the present invention.

5 is a partially omitted enlarged front view of a lower ram shown in FIG. 4;

FIG. 6 is a central vertical partial sectional view of FIG. 5 showing an internal mechanism (lock mechanism) of the lower ram.

7 is a partial cross-sectional view taken along the line AA 'of FIG. 6, and FIG. 7 (a) is a view showing an unlocked state of a lock mechanism, and FIG.
FIG. 4 is a diagram showing a locked state of a lock mechanism.

FIG. 8 is a front view of a tool set incorporated in the molding press of FIG. 4;

FIG. 9 is a cycle diagram of the molding press of FIG. 4;

FIG. 10 shows a slide, a lock cylinder and a lower ram;
Operation | movement explanatory drawing in a home position, a molding process, a knockout process, and a filling process.

[Explanation of symbols]

 Reference Signs List 1 press 2b hydraulic cylinder (drive cylinder) 3 toggle mechanism 4 slide 7 tool set 8 lower ram 9 link mechanism 10 link arm 11 link plate 12 bed 14 lock mechanism

Claims (4)

[Claims] 1. A powder molding press in which a slide provided with an upper ram moves up and down by a toggle mechanism connected to a drive cylinder, the powder forming press being connected to the slide and the lower ram and following up and down movement of the slide. And a link mechanism for vertically moving the lower ram. 2. A link mechanism portion, wherein an upper end portion is rotatably connected to a slide and extends to the side of a lower ram, and is rotatably connected to a bed and a link arm, respectively. A link plate rotatably connected to the lower ram between these connection points, wherein the link plate has a connection point to the bed as a rotation fulcrum and the lower ram and the link arm. The powder molding press according to claim 1, wherein the powder molding press is moved up and down in the same direction. 3. A link mechanism having an upper end rotatably connected to the slide and extending to the side of the lower ram, and a link arm rotatable with respect to the lower ram and the link arm, respectively. A link plate connected to the bed and rotatably connected to the bed between these connection points, wherein the link plate has a connection point with respect to the bed as a swing fulcrum and the lower ram and the link arm. The powder molding press according to claim 1, wherein the powder molding presses are moved up and down in opposite directions. 4. The powder molding press according to claim 3, wherein the link mechanism includes a lock mechanism for locking or unlocking the connection of the link plate to the lower ram.