JPS62202002A - Nc mechanical press - Google Patents

Abstract

PURPOSE:To exactly and easily control the molding of optional works by numerically controlling the strokes and operation time of upper and lower punches of a powder molding press by an NC device and correcting the packing depth of the lower punch in accordance with the actually measured pressing pressure. CONSTITUTION:The strokes and operation time for determining the amt. of compression, packing density, output of molded moldings, etc., of the above- mentioned respective punches 9, 16, 19' of the mechanical press for pressing powder 26 by the upper punch 9 and the lower outside punch 16 and the lower inside punch 19' are preset and are inputted and stored into the NC device (not shown). Punch driving mechanisms 47, 50, 51 provided with servocontrol motors 40 are controlled by the command of the NC device based on the above- mentioned set values and the punches 9, 16, 19' are driven via arms 44, 48, 49. The pressing pressure is detected by a load cell 31 and the packing depth of the lower punches 16, 19' is quickly and automatically corrected to the set values in accordance with the measured values.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a mechanical press that has the ability to accurately and easily set and control strokes in order to mold powder into accurate dimensions with accurate pressure. It is.

Conventional technology A conventional mechanical press for powder molding is shown in Figures 6 and 7.
It is shown in the schematic diagram of the main part configuration in the figure. 6 and 7, the lower bunch cam 2. The upper bunch cam 3 and the push-out cam 27 are fixed to the camshaft 1. upper bunch cam 3
A support yoke is provided on the roller follower 4 whose upper part is transferred, and a spring 22 is attached to the tip of the support yoke.
is fixed to the main body of the mechanical press. An upper bunch lever 5 is provided on the shaft 4a of the roller follower 4 so as to be swingable about a fulcrum 5a, and the fulcrum 5a is fixed to the main body of the mechanical press. On the other hand, an upper punch shaft 6 that vertically penetrates the frame 32, 33 of the mechanical press and can slide up and down is provided, and an upper bunch 9 is attached to the lower part of the upper bunch shaft 6. A threaded portion is provided in the middle, and an upper punch raising nut 7 and an upper bunch pressurization amount adjusting nut 8 are attached by sandwiching the upper punch lever 5. Note that a load cell 31 is installed at the bottom of the upper punch shaft 6.
Incorporate.

Next, the roller follower 10 is transferred over the lower punch cam 2.
A parallel ring mechanism 11 is provided at the tip of the spring 2.
5, and the spring 25 is fixed to the main body of the mechanical press. A lower outer punch lever 12 and a lower inner punch lever 18 are provided to be slidable about fulcrums 12a and 18a, respectively, by the parallel link mechanism 11, and a spring 23 and a spring 24 fixed to the main body of the mechanical press are respectively attached.

A die 17 is installed on the table surface 34 of the mechanical press (
The material (powder) 26 is filled. A lower outer punch 16 is fixed to the upper part of the lower outer punch shaft 13, and the lower outer punch 16 is slidably moved up and down within the die 17. Further, a lower inner punch shaft 19 is provided which can slide up and down within the lower outer punch shaft 13, and a lower inner punch 19' fixed to the upper part of the lower inner punch shaft 19 can slide up and down within the lower outer punch 16. do. The lower outer punch shaft 13 passes through the frame 35 vertically.

A threaded portion is provided at the lower part, and a lower outer punch compression adjusting nut 1-14 and a lower outer punch filling mother adjusting nut 1-15 are attached to the upper and lower sides of the lower outer bump 1 collar 12. In addition,
The lower surface of the lower outer punch filling semi-adjustment nut 1-15 is in contact with the upper surface of the frame 36.

In addition, the lower end of the threaded portion of the lower outer bunch shaft]-13 below the neck 1-15 is connected to the vertical hole 36a of the frame 36.
It is loosely inserted into the

Further, the lower inner punch shaft 19 vertically passes through the frame 36, has a threaded portion at the lower part, and holds the lower inner punch (/bar 18 between the downward punch compression amount adjusting nut 20 and the downward punch shaft 19). Side punch full 11ffl adjustment nut 2
Attach 1. Note that the lower surface of the downward punch filling amount adjusting knob 1-21 is in contact with the upper surface of the frame 37.

Further, the lower end of the threaded portion of the lower inner punch shaft 19 below the neck 1-21 is loosely inserted into the vertical hole 37a of the frame 37.

On the other hand, a roller follower 38 rolling on the extrusion cam 27
A parallel link mechanism 28 is provided at the tip of the spring 3.
9 is attached, and the spring 39 is fixed to the main body of the mechanical press. The lower outer punch lever 12 and the lower inner punch lever 18 have two forks at the fulcrum 12a and the right side of the fulcrum 18a, and a lower outer punch extrusion adjustment screw 29 and a lower inner punch are installed at the right end of one of the two forks, respectively. An extrusion level adjusting screw 30 is provided.

In the above configuration, the operations of each punch of the mechanical press are as follows.

(1) Operation of the upper bunch 9 Due to the drive of the camshaft 1, the upper bunch 9 is moved by the force of the upper bunch lever 5 transmitted from the upper punch cam 3 via the upper punch raising nut 7 and the upper bunch pressurization amount adjustment nut 8. Go up and down.

(2) Operation of the lower outer punch 16 When the camshaft 1 is driven, the lower outer bunch lever 12 is tilted by the force of the pressurizing parallel link mechanism 11 transmitted from the lower bunch cam 2. The force of this inclination causes the upper punch compression adjustment nut 14 and the lower body punch filling amount adjustment nut 1 to be adjusted.
5, the lower outer punch 16 moves up and down.

In addition, since the workpiece must be extruded after applying pressure,
The lower outer bunch lever 12 is further tilted by the force of the pushing parallel link mechanism 28 transmitted from the pushing cam 27.

The workpiece is pushed out by the force of this inclination, and then the lower outer punch 1
Lower 6.

(3) Operation of the lower inner punch 19' is similar to the lower outer punch 16 described above. However, with one lower bunch cam 2, the lower inner punch 19' is used.

The lower outer punch 16 is operated.

(4) Interlocking each punch Figure 8 shows the operation of this mechanical press.

The vertical axis shows the working distance of each punch, and the horizontal axis shows the cam rotation angle (degrees).
It's great. Lower outer punch 16° Lower inner punch 19'
The operation is a combination of the lines drawn by the lower punch cam 2 and the pusher cam 3, and the drive from point 0 to 0 in the figure is driven by the pusher cam 27, and below that the drive is driven by the lower bunch cam 2. Driven. However, ■ and ■ above are the fulcrum points of the diagram showing the movement of the lower outer punch 16 by the lower bunch cam 2 and the diagram showing the movement of the lower outer punch 16 by the extrusion cam 27.

Note that the lower diagram in FIG. 8 shows the molding process of the workpiece corresponding to the upper diagram.

(5) Reading of press pressure The load applied to the upper punch 9 by the load cell 31 shown in FIG. 6 is read.

Further, the adjustment of each punch of the mechanical press is as follows. That is, since the stroke of each cam is fixed, the filling depth, compression ratio, and extrusion amount of each punch are determined by the following method.

(1) Rising side punch filling depth Yl While looking at Yl in FIG. 6, move the lower outer punch filling ff1l adjustment nut 15 and move the lower outer punch shaft 13 up and down to determine (move at the minimum lift point).

(2) Downward side punch filling depth Y2 While looking at Y2 in Fig. 6, move the downward side punch filling level adjustment nut 21 and move the downward side bunch shafts 1 to 19 up and down to determine (Riff) - Minimum point (3) Lower outer punch compression amount Distance
2 (play) is set to O, determine the maximum lift amount by the lower bunch cam 2, and move the lower outer punch compression amount adjustment nut 14 to determine the maximum lift - x 2 - predetermined compression amount.

(4) Lower inner punch compression amount Distance X3 (
The maximum lift amount by the lower bunch cam 2 is determined by moving the downward punch compression amount adjustment knob 1-20 so that the maximum lift - x 3 - predetermined compression amount is obtained.

(5) Upper bunch compression layer Distance I between the lower surface of the tip of the upper bunch lever 5 and the upper surface of the upper punch pressure amount adjustment nut 8 in FIG. 6! IX1 (play) is set to O, the maximum lift amount by the upper punch cam 3 is determined, and the upper punch pressurization amount adjusting nut 8 is moved to determine the maximum lift - Xl - a predetermined compression amount.

(6) Lower outer punch extrusion amount The distance mzi between the upper surface of the die 17 and the upper surface of the lower outer punch 16 is set to the lower outer punch so that the workpiece is sufficiently pushed out at the point where the lift by the extrusion cam 27 in FIG. 7 is maximum. The punch extrusion control is determined by the adjustment screw 29.

(7) Amount of lower inner punch extrusion The distance Z2 between the upper surface of the die 17 and the upper surface of the lower outer punch 19' is lowered so that the workpiece is sufficiently extruded at the point where the lift by the extrusion cam 27 in FIG. 7 is maximum. It is determined by the outer punch extrusion amount adjustment screw 30.

Problems to be Solved by the Invention The conventional mechanical press for powder molding as described above has the following problems.

(1) Each punch must be adjusted every time the workpiece changes, which is cumbersome. Therefore, it is not suitable for high-mix, low-volume production.

(2) If you try to change the cycle diagram in Figure 8, you will have to replace the cam. Therefore, the cycle is semi-fixed, and pressing cannot be performed by changing various conditions.

(3) When trying to press precision products (tolerance of about 5μ), the filling depth and compression layer are determined by screws, so
The pitch is rough and does not fall within the target tolerance.

(6) When trying to press a product that requires precise pressure control, it is necessary to input the material (powder) accurately, but in order to control the scraping on the top surface of the die, it is necessary to There is no guarantee that the material will be thrown into the
1m adjustment nut 15. Lower inner punch filling layer adjustment nut 21
Adjustment is required. Therefore, the nut must be adjusted while checking the value of the opening cell 31, resulting in low productivity.

Means for Solving the Problems In order to solve the above problems, the present invention provides a plurality of upper punches and a plurality of lower punches fixed to each of the plurality of punchers 71-, each of which is driven by an independent motor (for example, a servo motor). )
By ball screw, arm.

It is driven via a punch shaft, and these multiple motors are controlled by an NC device, and the compression amount and filling depth of the upper and lower punches of the powder forming press are controlled.

an input means for presetting the stroke and operation time of each of the punches for determining the extrusion amount for extruding the molded body; an NC device for storing the set data; and an NC device for storing the set data; It has a punch drive mechanism that drives individual arms linked to each of the punches in response to a command from the device, and a load detection means that measures the press pressure of the punch, and based on the measurement data of the load detection means, the NC
The device is configured to correct the filling depth of the lower punch.
C mechanical press.

Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic diagram of the main parts of an NC mechanical press according to the present invention, FIG. 2 is a schematic diagram of the main parts of a punch driving section, and FIG. 3 is a block diagram of an NC device for driving the punches.

1 and 2, the same parts as in FIG. 4 are given the same reference numerals.

As shown in Fig. 2, a ball screw drive unit is provided in place of the cam drive unit, and an NC drive unit is provided for each axis of each punch to control the vertical stroke of each punch. An NC device that can coordinately control the motors is provided. Also, no nuts are attached to each punch shaft, but two collars are fixed facing each other at regular intervals.

The operation of the NC mechanical press of the present invention is as follows.

(1) The rotational force of the punch drive unit DC servo motor 40 is applied to the small gear 41 and the large gear 4.
The signal is amplified by a speed reducer having a transmission speed of 2 and transmitted to the ball screw 43. The ball screw 43 converts rotational force into linear force,
The upper bunch arm 44 is tilted about the fulcrum 44a, and the upper punch shaft 6 is attached via the collar 5a and the collar 6b.
Raise and lower.

Note that the DC servo motor 40 is equipped with a tacho generator 45. A pulse encoder 46 is attached. Further, 47 is an upper punch drive mechanism.

(2) Operation of each punch As shown in FIG. 1, the lower outer punch shaft 13 and the lower inner punch shaft 19 each have a lower outer bunch arm 48. A non-operating side punch drive mechanism 50 . which is the same as the upper punch drive mechanism 47 is connected to the lower inner bunch arm 49 . Attach the lower inner punch drive mechanism 51. Lower outer bunch arm 4
8 tilts around the fulcrum 48a, so the collar 13a
, the lower outer punch shaft 13 moves up and down via the column 13b.

Similarly, since the lower inner punch arm 49 tilts around the fulcrum 49a, the lower inner punch shaft 19 moves up and down via the collars 19a and 19b. Therefore, each punch fixed to each punch shaft can move freely.

(3) Punch drive NC device Part (A) of the control block diagram shown in Figure 3 is provided for each punch shaft, and each punch can be set to a preset filling depth by commands from a control device consisting of a microcomputer or sequencer. The compressor and extruder shall operate in accordance with the extrusion bond. Here, if an abnormally large amount of material (powder) is packed, the motor may burn out, so an output current limiting circuit is installed to perform torque control.

Further, as shown in FIG. 1, a circuit (B) for reading the press pressure of the upper bunch 9 with a load cell 31 is provided so that it can be read by the control device of the NC device.

The read load data F is analyzed according to the flowchart showing the analysis procedure in Figure 4, and the filling depth is calculated using the filling depth correction data table (stored in advance in the NC system) corresponding to the read load F in Figure 5. The correct filling depth is determined.

In addition, in Fig. 4, WO is the target value of the load, and B
, C, and a are each constants.

Next, a method of inputting initial setting data for each punch will be explained using the upper punch 19 as an example. FIG. 9 shows an example of an input device 52 for inputting setting values, including a CRT 53. It consists of a coordinate setting input section 541 and a working distance correction input section 55. The procedure for inputting setting values is as follows.

(a) Input the operating stroke of the upper bunch 9.

First, press the coordinate setting key 54a5, the vertical axis (indicating the working distance) key 54b, and the upper bunch key 540, and input the uppermost end path 111HI and the lowermost end distance 11[tH2 of the upper punch 9 from the numeric keypad 54d.

(b) Next, set the time value for the upper punch operation.

First, the horizontal axis key (indicating a time value) 54b'.

Press the upper punch key 540 to enter the time values Ti and T for each operation.
2, T3, and T4 are input from the numeric keypad 54d.

(C) Since the input of each setting value of the upper bunch 9 is completed, press the end key 54e.

(d) Each of the above setting values is stored in the NC device, and the NC device calculates a cycle diagram from these setting values and displays it on the CRT53.
Display it as a graph. Further, the operating speed of the upper bunch 9 is calculated by the NC device from the above set value, and the value is stored.

(e) Lower inner punch 19' using the same procedure as above.

Setting values for the upper and lower stroke distances and operation time of the lower outer punch 16 are input and stored in the NC device.

(r) The NC device calculates the compression amount and filling depth to control the operation of each punch, and the extrusion peak for extruding the formed product based on each of the above set values, and stores the values. do.

(C+>Next, set the relationship between the press load and the filling depths Yl and Y2 of the lower outer punch 16° and the lower inner punch 19'. First, press the load setting key 598 of the load input section 59.
．． Press the target value key 59b and input the target value WO of the press load using the numeric keypad 54d. Subsequently, the load setting width a is also input in the same manner. Then, the NC device is CRT53
A data table as shown in Fig. 10(b) is displayed. Enter the filling depth correction value corresponding to the corresponding load using the numeric keypad 5.
Input using 4d. This filling depth correction value may be set automatically according to a predetermined calculation procedure using an NC device, in addition to inputting it using the numeric keypad 54d.

Similarly, input the filling depth correction value for the lower outer punch.

Next, a method for correcting the working distance of the upper punch among the above set values due to a malfunction or the like during press forming will be explained.

(a) First, press the working distance correction key 55a and the upper punch key 55b. Then, as shown in FIG. 8, a cycle diagram is displayed on the CRT 53 based on the set values stored in advance in the NC device. Also, a cursor 56 for correction
is also displayed.

(b) Force ~ Move the crane 56 to the correction location using the ← and → keys. At this time, the cursor 56 is displayed on the display device 57.
The coordinate values of the cycle diagram will be displayed as the cycle diagram moves.

(C) Next, while pressing the ↑ or ↓ key,
Since the working distance can be increased or decreased at intervals of seconds, when the desired value is reached, the operator stops pressing the ↑ or ↓ key and presses the end key 58. Through this operation, the corrected value is stored in the NC device.

(d) Modification of other punch setting values is also performed in the same manner as above.

The NC mechanical press of the present invention controls the ball screw by controlling the DC servo motor based on the filling depth, compression amount, and extrusion suspension of the lower outer punch, the lower inner punch 7, and the upper bunch stored in advance in the NC device. By rotating the arm 43, the arms 44, 48, 49 can be driven, and the raising and lowering of the lower outer punch, lower inner punch, and upper bunch can be precisely controlled according to set values. Further, when it becomes necessary to change these setting values, by connecting the input device 52 to the NC device, it becomes possible to easily change the setting values stored in the NC device.

Furthermore, the NC device is equipped with a lower outer punch, a downward punch,
It is also possible to memorize the speed constants (acceleration and deceleration) for raising and lowering the upper bunch, and based on these set values, control the speed of each punch according to the set values according to the procedure shown in part (B) of Fig. 3. It becomes possible.

In the above embodiment, a ball screw 43 is used as the drive mechanism 47 for each punch, but an electro-hydraulic stepping cylinder or the like may be used instead of the ball screw.

Further, in the present invention, the press pressure is measured by the press load detection means 31, and based on the measured value, the filling depth of one or both of the downward side punch 19' and the lower outer punch 16 is determined based on a preset value. can be automatically corrected.

Effects of the Invention As described above, the present invention has the following effects.

(1) Even if the workpiece changes, settings such as the stroke of each punch can be made by simply changing the data manually, making it suitable for high-mix, low-volume production.

(2) Since the cycle diagram showing the movement of each punch can be freely changed and pressing can be performed under various conditions, uniform molding of complex workpieces can be expected.

(3) When pressing precision products, each punch moves by pulse feeding, making it easy to achieve target tolerances.

(4) When pressing products that require precise pressure control, there is no need for nut adjustment in the conventional technology, and stroke and filling depth can be quickly changed by trial and error by key operation. Furthermore, automatic pressure adjustment speeds up production.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the main parts of the NC mechanical press of the present invention, Fig. 2 is a schematic diagram of the main parts of the punch drive section, Fig. 3 is a block diagram of the punch drive NC device, and Fig. 4 is load data. Fig. 5 is a filling amount correction data table corresponding to the read load, Fig. 6 and M7 are schematic diagrams of the main parts of a conventional mechanical press, and Fig. 8 is a diagram showing each of the conventional mechanical presses. A cycle diagram showing the movement of the punch and a diagram showing the corresponding molding process of the workpiece; FIG. 9 is a diagram showing an example of a setting value input device used in the present invention; FIGS. 10(a) and (b) is the CRT in Figure 9.
It is a figure showing an example of a display. 6... Upper punch shaft, 9... Upper bunch, 13.
...Lower outer punch shaft, 16...Lower outer punch,
1... Downward side punch shift, 19'... Downward side punch, 31... Load cell, 40... DC servo motor, 43... Ball screw, 44.48.49...
・Arm, 47.50.51...Punch Kakeru 11!71
Mechanism, 52... input device. Figure 5 Figure 7 Figure 8 Force A Romatsu fI 4 degrees (degrees) Figure 10 (Q') Figure 10 (A)

Claims (1)

[Claims] Input for presetting the stroke and operation time of each punch to determine the compression amount, filling depth, and extrusion amount for extruding the molded product of the upper punch and lower punch of the powder molding press. an NC device for storing the set data; a punch drive mechanism for driving individual arms linked to each punch according to commands from the NC device; and a load detection device for measuring press pressure of the punches. Based on the measurement data of the load detection means, the N
An NC mechanical press characterized in that the device C is configured to correct the filling depth of the lower punch.