JP2764538B2 - Powder molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding machine for filling a cavity such as a metal powder, a chemical conversion powder and a ceramic powder into a cavity in a mold and press-molding the same.

[0002]

2. Description of the Related Art As a molding machine for filling a cavity such as a metal powder or a ceramic powder into a cavity in a mold and press-molding, there are conventionally a single-shot molding machine called a reciprocating machine and a rotary machine.

In the single-shot type, a convex type and a concave type are respectively fixed to upper and lower punch holders which reciprocate only in the vertical direction, and pressure is applied to a die via a pressure transmitting mechanism such as a link, a cam, a cylinder, or the like. . In the rotary type, when the table holding the lower punch holder rotates, the upper punch holder is lowered when the lower punch holder comes to a predetermined position, pressure is applied to the mold via the pressure transmission mechanism, and the other positions are set. In this method, a large amount of molding can be performed at the same time by performing an operation of filling a powder or taking out a molded body from a mold.

[0004]

However, in any of the methods, since only one type of mold can be fixed to the punch holder and the stroke of the punch holder is constant, it is not possible to mold a product with a small number of articles. . In addition, in the case of the rotary type, since one cycle is fast, a product having a complicated shape cannot be formed in order to prevent damage to the mold. On the other hand, it is not possible to install a different molding machine for each product number in a factory having a limited area. SUMMARY OF THE INVENTION An object of the present invention is to provide a molding machine capable of producing a large number of products in small quantities and occupying a small area.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a powder molding machine of the present invention fills a powder between a pair of concave and convex molds and press-molds them. And a supply mechanism for supplying powder to the mold, and holding the mold .
It supports the upper and lower punch holders, a pressure transmission mechanism that transmits pressure to these punch holders, an ejector mechanism that removes the molded body from the mold, and a vertically movable punch holder.
A pair of molding stations that can move horizontally between a supply mechanism, a pressure transmission mechanism, and an ejector mechanism, a power transmission mechanism that transmits a driving force to the molding station, and assists the driving force
And an auxiliary drive source. The power transmission mechanism
Drive side, follower side each connected to molding station
This is a toggle link. The auxiliary drive source is for opening the toggle link.
Each molding station should be parallel to the follower link at the time.
Connected to the site.

[0006] As a driving source and an auxiliary driving source in this case, a crank coupled to a servo motor or the like, a ball screw, although a rack and pinion, and the like, desirable are driving source
Are cylinders , and the auxiliary drive source is an auxiliary cylinder that operates synchronously with each molding station.

[0007] A supply mechanism used in this powder molding machine and
Of the ejector mechanism, supply operation and ejector operation
An appropriate mechanism for raising and lowering the lower punch holder at this time includes a bracket facing the lower end surface of the lower punch holder, a chuck that is swingably fixed to the bracket and can grip the lower punch holder, and a lower inner side of the chuck. An elastic member mounted between the bracket and providing a restoring force against swinging of the chuck, and having a guide surface that can be tapered toward the chuck and abut against a lower outer ridge line of the chuck,
It comprises a chuck guide cam that can be moved horizontally, a cam cylinder that urges the chuck guide cam to move horizontally, and a bracket cylinder that moves up and down the bracket.

It is particularly desirable that the supply mechanism and the ejector mechanism are provided with holes communicating with each other on the upper surface of the bracket and the side surface of the chuck guide cam, and the holes on the upper surface are provided with an overfill plan which can contact the lower end surface of the lower punch holder. A jar is fitted with another elastic member, and a hole in the side surface of the chuck guide cam is urged by a cam cylinder together with the chuck guide cam to raise the overfill plunger against the restoring force of the elastic member. It is the one with the jercam fitted.

[0009]

[Action]

[Claims 1 and 2] A pair of upper and lower punch holders are provided for each molding station, and both punch holder pairs are simultaneously pressed and depressurized via a toggle link by a driving force from one driving source. Since the operation and the operation of removing and supplying the compact are performed, two types of compacts can be manufactured simultaneously in parallel. In addition, when the follower link of the toggle link is closed or completely opened, the angle of the follower link with respect to the original link is a blind spot (almost 0 ° or approximately 180 °). Since the power can be moved by the driving force of the auxiliary driving source, the toggle link can be transmitted with a small force without applying excessive force to the toggle link.

If the driving source is a cylinder and the auxiliary driving source is an auxiliary cylinder that operates synchronously with each molding station, the driving force can be easily adjusted with a small occupied volume.

[Claims 3 and 4] When the toggle link is closed by the driving force of the driving source and the auxiliary driving source after the pressurizing / depressurizing operation is completed, the forming station moves right above the bracket and moves up and down. The concave and convex molds are separated from each other with the punch holder. Then, the upper surface of the bracket and the end surface of the lower punch holder face each other. In this state, when the bracket cylinder is operated and the bracket is pushed upward, the lower punch holder fits into the chuck and contacts the upper surface of the bracket, and then is pushed up by the urging force of the bracket cylinder, and the molded body is ejected accordingly. Is done. The ejected molded body is sent to the next step.

Subsequently, when the pressure of the bracket cylinder is reduced, the chuck descends together with the bracket while holding the lower punch holder by the restoring force of the elastic member. When lowered to a predetermined position, the powder is filled into the concave mold from the feeder. Then, the cam cylinder is operated to move the chuck guide cam toward the chuck. When the guide surface of the chuck guide cam comes into contact with the ridge line on the lower outside of the chuck, the guide surface is tapered, so that the chuck swings with the movement of the chuck guide cam, and the opening edge of the chuck opens. . As a result, the lower punch holder is released from the chuck. Then, when the drive source and the auxiliary drive source are operated, the toggle link starts to open, and the upper and lower punch holders move toward the pressing operation together with the forming station.

As described above, since the molding ejector operation and the powder supply operation can be performed at the same position, the moving distance of the molding station can be reduced, the number of steps can be reduced, and the entire molding machine can be reduced in size. Incidentally, the powder filling amount can be freely adjusted by the stroke of the bracket cylinder.

If the chuck is provided with an overfill plunger and a plunger cam, when the chuck guide cam moves toward the chuck, the plunger cam causes the overfill plunger to resist the restoring force of the elastic member. Push up. Then, the upper surface of the powder filled in the concave shape of the lower punch holder rises from the opening end surface of the concave shape. Therefore, when the feeder that has finished filling the powder retreats, the powder overflowing from the concave shape is scraped off, whereby the powder filling amount is cut off. Accordingly, since the operation of ejecting the compact and the operation of supplying the powder can be performed at the same position even when the powder is overfilled, the number of steps is further reduced and the compacting machine is downsized.

[0015]

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view of the powder molding machine, and FIG. 2 is a right side view. The powder molding machine is basically symmetrical, but in FIG. 1, the left half represents a powder filling state and the right half represents a pressurized state.

The powder molding machine has a main body 1, a pair of molding stations 2 and 2, upper and lower punch holders 31 and 32 supported so as to be able to move up and down, and fixed to the main body 1 above the molding station 2. An upper cam 41 and a lower cam 4 also fixed below the molding station 2
2, a supply mechanism for supplying powder to the mold as described in detail below, a power transmission mechanism for transmitting a driving force to the molding station 2, a pressure transmission mechanism for transmitting pressure to the punch holder, and an ejector for removing the compact from the mold. It consists of a mechanism and a control device. The upper punch holder 31 holds a convex (upper punch) 33, and the lower punch holder 32 holds a concave die composed of a die 34 and a lower punch 35.
The upper and lower punch holders 31 and 32 and the upper and lower cams 4
1, 42, the supply mechanism, the pressure transmission mechanism, and the ejector mechanism are all symmetrically set toward the front, two in total.
A set is provided.

Each of the molding stations 2 and 2 has an upper front and rear 2 which has a vertical U-shaped cross section and is horizontally fixed to the main body 1.
The slide shafts 21, 21, 21 are movably fixed to the slide shafts 21, 21, 21 via oilless slide bushes 22. And molding station 2
A cam follower 23 having a U-shaped cross section for receiving the cam follower 23 and supporting the molding station 2 together with the slide shaft 21 in a pressurizing step is provided on both left and right ends of the main body 1. Fixed.

A car-shaped cam follower 36 is attached to the upper punch holder 31 so as to protrude rearward, and a flange 37 is formed at the lower end of the lower punch holder 32.
The upper cam 41 has a cam surface formed of a horizontal surface and a slope that descends outward following the horizontal surface, while the lower cam 42 has a cam surface formed of a slope that rises outward. ing. These upper and lower cams 41, 42
Guides the punch holders 31, 32 to the position of a supply mechanism, a pressure transmission mechanism or an ejector mechanism based on the horizontal movement of the molding station. Above the guide surface of the lower cam 42, a cylindrical cam follower 43 is fixed to the main body 1 by an air cylinder 44 so as to be able to move back and forth.

The supply mechanism includes a hopper 5 for storing powder.
1, a feeder 52 for filling the mold with the powder dropped from the hopper 51, a feeder air cylinder 53 for reciprocating the feeder 52 toward the mold, and a lower punch holder 32.
, A chuck 62 fixed to the shaft 61a of the bracket 61 so as to be swingable, a chuck guide cam 63 movable toward and away from the chuck 62, and a horizontal movement caused by the chuck guide cam 63 fixed to the bracket 61. And a bracket cylinder 65 fixed to the main body 1 to move the bracket 61 up and down. The bracket cylinder 65 has a male screw 65a formed on the outer periphery of a ram penetrating the frame 1a of the main body 1, and the female screws 65b, 65c with the frame 1a interposed therebetween.
Is engaged with it.

The structure near the bracket 61 will be described in more detail with reference to FIGS. 3 is an enlarged front view of the vicinity of the bracket 61 of FIG. 1, FIG. 4 is a plan view of the same, and FIG.
It is AA sectional drawing of. As shown in the figure, the chuck 62 has a claw 62a having an inclined edge at the upper end so that the lower punch holder 32 can be gripped. Chamfered part 62b
Are formed. A spring 66 for applying a restoring force against the swing of the chuck 62 is mounted between the lower inner side of the chuck 62 and the bracket 61. The chuck guide cam 63 is tapered toward the chuck so that the guide surface 6 can contact the C chamfered portion 62 b of the chuck 62.
3a, and is integrated with a plunger cam 63b described later.

A hole communicating with each other is provided on the upper surface of the bracket 61 and the side surface of the chuck guide cam 63, and an overfill plunger 67, which can contact the lower end surface of the lower punch holder 32, is fitted into the hole on the upper surface together with a spring 68. A plunger cam 63b urged by a cam cylinder 64 together with the chuck guide cam 63 and capable of raising the overfill plunger 67 against the restoring force of the spring 68 is provided in a hole on the side surface of the chuck guide cam 63. It is fitted. The tip of the plunger cam 63b has a frustoconical guide surface.

The bracket 61 is fixed to a ball slide unit 69 fixed to the main body 1 so as to be vertically movable. When the bracket cylinder 65 is operated, the verticality of the lower punch holder 32 held by the chuck 62 is adjusted. It is supposed to be maintained. Of these, bracket 6
1, the chuck 62, the bracket cylinder 65, and the ball slide unit 69 also serve as an ejector mechanism.

The power transmission mechanism is a toggle link 7 and a hydraulic cylinder as a drive source
71 is connected to the follower side link, forming station 2,
2 are connected. When the toggle link 7 is in a blind spot, the auxiliary hydraulic cylinder 72, which operates synchronously, serves as an auxiliary drive source for assisting the driving force.
Reference numeral 72 is connected to each of the molding stations 2 and 2 in parallel with the follower side link when the toggle link 7 is opened (the right half in FIG. 1). The pressure medium of the bracket cylinder 65 is also oil, and the pump 73 for sending the medium oil to each of the hydraulic cylinders is fixed to the back surface of the main body 1 (FIG. 2).

The pressure transmitting mechanism is rotatably fixed to the main body 1 above the molding station 2 and has an upper pressure roller 81 having a tangent substantially on the extension of the upper cam 41 surface. An upper worm wheel 82 and an upper worm gear 83 meshing therewith connected at an eccentric position, and a lower pressure roller 84, a lower worm wheel 85, and a lower worm gear 86 similarly provided below the molding station 2.
And a pressure timing adjustment screw 87 fixed to the main body 1 and having a bearing (not shown) having a tip rotatably receiving the lower pressure roller 84 shaft. The shaft hole (not shown) of the main body 1 that receives the shaft of the lower pressure roller 84 is an elongated hole so that the shaft can finely move horizontally with the screw movement of the pressure timing adjusting screw 87. The lower pressure roller 84 can be fixed to the main body 1 at a desired position by a fastening screw (not shown) inserted into the end surface of the lower pressure roller 84 via a washer or the like.

Although not shown, the control device, based on a signal sent from the operation box S, opens the toggle link 7 after the powder supply mechanism finishes the powder filling operation, and causes the molding stations 2 and 2 to transmit the left and right pressure transmission mechanisms respectively. To start the pressurizing operation. After the pressurizing operation is completed, the toggle link 7 is closed, and the molding stations 2 and 2 are returned to the powder supply / ejector mechanisms to start the operation of removing the molded body. A control circuit for controlling the power transmission mechanism and the powder supply / ejector mechanism so as to start the powder filling operation is set up. The operation state when the powder is molded by the powder molding machine of this example will be described below from the point where the pressing operation is completed, the molded body is taken out, and the powder supply operation is started again.

[Powder Filling and Overfilling Step] After the bracket 61 is raised and the molded body is knocked out from the concave mold, the claws 62 a of the chuck 62 are lowered by the bracket cylinder 65 while clamping the flange 37 of the lower punch holder 32. The punch holder 32 is lowered to a fixed position. The fixed position is a position where the female screw 65b hits the frame 1a. At the same time, the feeder 52 moves forward, moves the knocked-out compact to the chute 54, and fills the powder in the feeder 52 into the die 34 of the mold. Then, by operating the cam cylinder 64 and moving the guide surface 63a of the chuck guide cam 63 forward while contacting the C chamfered portion 62b of the chuck, the claw 62a of the chuck 62 is opened against the restoring force of the spring, advancing the plunger over the cam 63b with the same force of the cam cylinder 64, the over fill-plunger -67 and their causes immediately the lower punch holder 32 above raised a few millimeters, the powder overflowing from the die 34 side with it, the feeder 52 When you retreat, scrape and cut.
Thus, the powder is evenly filled in the concave mold. In addition, since the female screw 65b moves up and down by turning the female screw 65b, the powder filling amount can be freely changed.

[Underfill and Forming Preparatory Step] After the feeder 52 retreats, the follower side link of the toggle link 7 is opened by the force of the hydraulic cylinder 71 and the auxiliary hydraulic cylinders 72, 72, and the forming stations 2 and 2
1 and move toward the outside of the main body 1. However, at this time, since the toggle link 7 is in a blind spot with respect to the direction of the force of the hydraulic cylinder 71, the forming station 2 is first moved horizontally outside the main body 1 by the force of the auxiliary hydraulic cylinder 72. Then, the hydraulic cylinder 71 starts to apply a force near a position where the upper punch holder 31 and the lower punch holder 32 are pre-pressed by the upper and lower cams 41 and 42 as described later.

With the movement of the molding station 2, the upper punch holder 31 is lowered by the guide of the cam follower 36 and the upper cam 41, and the lower punch holder 32 approaches the underfill process while being raised by the guide of the lower cam 42. On the other hand, immediately before the lower punch holder 32 comes to the position of the cam follower 43, the air cylinder 44 operates to advance the cam follower 43, and the flange 37 of the lower punch holder 32 is moved.
Wait several millimeters below the top surface. Then cam follower 4
3 while passing through the flange 37 of the lower punch holder 32.
Is in contact with the lower peripheral surface of the cam follower 43 and is pushed down by several millimeters while rotating the cam follower 43.
At the same time, the upper surface of the powder filled flush with the surface of the concave die 34 is lowered several millimeters together with the lower punch 35. Immediately thereafter, the upper punch holder 31 is guided by the upper cam 41 and further descends, and accordingly, the upper punch 33 comes into contact with the die 34. Since the upper surface of the filling powder is already lower than the opening edge of the die 34, the powder will not be scattered when the upper punch 33 is inserted. The punch holders 31 and 32 above and below the forming stations 2 and 2 that continue to move move toward the pressure rollers 81 and 84 while being pre-pressed by the upper cam 41 and the lower cam 42.

[Pressing process] The upper and lower punch holders 31 and 32 to which the preload is applied have the angle of the toggle link 7 of 170.
When the angle reaches 〜 ° to 178 °, it is pushed between the lowermost part of the upper pressure roller 81 and the uppermost part of the lower pressure roller 84. Further, the cam follower 23 of the molding station 2 fits into the cam follower guide 24. At this time, the upper and lower pressure rollers 81 and 84 are rotated by the punch holders 31 and 32. At the same time, punch holders 31, 32
Pressure is applied in between. Since the molding station 2 is supported by the three slide shafts 21 and the cam follower guide 24, there is no possibility that the molding station 2 will vibrate during pressurization and damage the mold.
In this state, the molding station 2 is stopped instantaneously or for a certain period of time, and the pressure in the molds 33 to 35 is molded into a predetermined shape by holding the pressure.

When it is desired to change the pressure of the punch holders 31 and 32 during the pressing operation, the following is performed. That is, the upper worm gear 83 is manually rotated. Then, since the upper worm wheel 82 rotates and the upper pressing roller 81 is eccentrically connected to the upper worm wheel 82, the upper worm wheel 82 is displaced in the vertical direction, the stroke of the upper punch holder 31 changes, and the pressure changes. The same applies to the lower punch holder 32.

Further, by loosening the fastening screw fastened to the shaft end surface of the lower pressure roller 84 and turning the pressure timing adjusting screw 87, the shaft of the lower pressure roller 84 moves slightly right and left. When the fastening screw is tightened again at a desired position, the timing at which the lower punch holder 32 reaches the uppermost portion of the lower pressure roller 84 can be adjusted. The timing of the upper punch holder 31 reaching the lowermost portion of the upper pressing roller 81 can be adjusted by providing a pressing timing adjusting screw having the same structure as the shaft end surface of the upper pressing roller 81.

After the completion of the pressure molding, the molding station 2 is moved toward the center of the main body 1 by the operation of the auxiliary hydraulic cylinder 72 and the hydraulic cylinder 71. At this time, since the underfill cam follower 43 is retracted by the operation of the air cylinder 44, it does not contact the lower punch holder 32. Then, both molding stations 2 move to the same knockout position as in the filling operation and temporarily stop. Since the toggle link 7 becomes a blind spot before reaching the knockout position, the forming station 2 is finally moved to the knockout position by the force of the auxiliary hydraulic cylinder 72.

[Knockout step] Molding station 2
Is temporarily stopped at the knockout position, the upper punch holder 31 is raised by the upper cam 41 and is at the powder filling preparation position. On the other hand, the lower punch holder 32 holds the lower cam 4
2 and is lowered to a position above the bracket 61. When the bracket 61 is raised by operating the bracket cylinder 65 in this state, the claw 62a of the chuck 62 is urged by the spring 66 and rises while grasping the flange 37 of the lower punch holder 32, and the molded body W is removed. It is pushed out of the die 34 (knock out). At this time, since the ball slide unit 69 is provided along with the bracket cylinder 65, the verticality of the lower punch holder 32 is maintained. Therefore, the lower punch 35 and the die 3
4 does not hurt. Thus, the molding is completed.

The amount of protrusion of the lower punch 35 during knockout is determined by the distance until the female screw 65c hits the frame 1a. Turning the female screw 65c causes the female screw 65c to move up and down. You can change it freely. After the knockout is completed, the compact W is slid on the chute 54 and sent to a conveyor (not shown).
Then, the process continues to the next cycle of the powder filling and overfilling steps.

[0035]

As described above, two types of molded articles can be produced in parallel and simultaneously, so that a large number of products can be produced in a short time without increasing the installation area occupied by the molding machine. it can. Moreover, molding can be performed under different conditions such as the stroke of the punch holder and the amount of powder filling.

[Brief description of the drawings]

FIG. 1 is a front view showing a powder molding machine according to an embodiment, in which a left half shows a powder filling state and a right half shows a pressurized state.

FIG. 2 is a right side view showing the powder molding machine of the embodiment.

FIG. 3 is a front view showing a main part near a bracket of the powder molding machine according to the embodiment.

FIG. 4 is a plan view showing a main part near a bracket of the powder molding machine according to the embodiment.

FIG. 5 is a sectional view taken along the line AA in FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Powder molding machine main body 1a ... Frame 2 ... Molding station 21 ... Slide shaft 22 ... Oilless slide bush 23 ... Cam follower 24 ... Cam follower guide 31, 32 ... Punch holder 36 ... Cam follower 37 ... Flange 33-35 ... Mold 33 upper punch 34 die 35 lower punch 41 42 cam 43 cam follower 44 air cylinder 51-54, 61-69 supply / ejector mechanism 51 hopper 52 feeder 53 feeder air cylinder 54 chute 61 ... Bracket 62 ... Chuck 63 ... Chuck guide cam 64 ... Cam cylinder 65 ... Bracket cylinder 66,68 ... Spring 67 ... Overfill plunger 69 ... Ball slide unit 7,71-72 ... Power transmission mechanism 7 ... Toggle link 71 ... Pressure cylinders 72 ... auxiliary hydraulic cylinders 81 to 87 ... a pressure transmission mechanism 81, 84 ... pressing roller 82, 85 ... worm wheel 83, 86 ... worm shaft 87 ... pressure timing adjustment screw

Claims (4)

(57) [Claims] 1. A powder was filled between the mold paired with the concave and convex, there is pressure molding, the vertical holding powder and a supply mechanism for supplying to the mold, the mold
And the punch holder, and pressure transmitting mechanism for transmitting the pressure to these punch holder, an ejector mechanism for removing the molded body from the mold, a vertically movable support the punch holder, feed mechanism, between the pressure transmission mechanism and the ejector mechanisms horizontal A pair of movable molding stations, the original side is connected to the drive source, and the follower side is connected to the molding station.
To transmit the driving force of the drive source to the molding station.
To parallel to the glue link, the follower side link open when this toggle link
Connected to each molding station to assist the driving force
A powder molding machine, comprising: an auxiliary drive source ; 2. The powder molding machine according to claim 1, wherein the driving source is a cylinder , and the auxiliary driving source is an auxiliary cylinder which operates synchronously with each molding station. 3. A method of filling a powder between a pair of concave and convex molds and press-molding, wherein a supply mechanism for supplying the powder to the mold, and a vertical mechanism for holding the mold. and the punch holder, and pressure transmitting mechanism for transmitting the pressure to these punch holder, an ejector mechanism for removing the molded body from the mold, a vertically movable support the punch holder, feed mechanism, between the pressure transmission mechanism and the ejector mechanisms horizontal In a device comprising a pair of movable molding stations and a power transmission mechanism for transmitting a driving force to the molding station, the supply mechanism and the ejector mechanism include a supply operation and an ejection mechanism.
Raise and lower the lower punch holder when operating the ejector
A mechanism is mounted between the bracket and the lower inside of the chuck, and a chuck that is swingably fixed to the bracket and opposes the lower end surface of the lower punch holder, and that is capable of gripping the lower punch holder. An elastic member that imparts a restoring force against movement, a guide surface that has a guide surface that expands in a tapered shape toward the chuck and can abut against a lower outer ridge line of the chuck, and a horizontally movable chuck guide cam;
A powder molding machine comprising: a cam cylinder that urges a chuck guide cam to move horizontally; and a bracket cylinder that moves a bracket up and down. 4. An overfill plunger, which can be in contact with the lower end surface of the lower punch holder, is fitted into the upper hole of the bracket and the side surface of the chuck guide cam together with another elastic member. A plunger cam, which is urged by a cam cylinder together with the chuck guide cam and can raise an overfill plunger against the restoring force of the elastic member, is fitted in a hole on the side surface of the chuck guide cam. Powder molding machine according to 1.