JP2019171420A - Forging-press and adjustment method of die height thereof - Google Patents

Abstract

To provide a forging product excellent in finish accuracy by properly adjusting a die height with a simple constitution.SOLUTION: A forging-press is provided with a load sensor 43 for measuring a load added to a work by striking of a slide, a hydraulic operation part 20 for adjusting a die height by adjusting a height of the slide and a PLC 41 for controlling the hydraulic operation part 20 on the basis of a variation in the load sensor 43. The PLC 41 preserves a reference load of a load detected by the load sensor 43, and controls so as to fall within a prescribed range by controlling the hydraulic operation part 20 when a difference of the reference load and an actual molding load is outside of the prescribed range by comparing the reference load and an actual molding load measured by the load sensor 43.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a forging press and a method for adjusting a die height thereof.

  2. Description of the Related Art Conventionally, a mechanical forging press that rotates a crankshaft and moves a slide up and down is known. In this type of forging press, a plurality of processes are performed, and the process in which the workpiece is present is detected, and the workpiece is automatically moved to a die height position set in advance for each arrangement pattern of the workpiece.

  When manufacturing a forged molded product by hot pressing, the finished product varies among the molded products, and the desired product accuracy may not be obtained. As the cause, thermal expansion of the mold, the mold holder, etc., mold wear, etc. can be considered. For this reason, in general, the user periodically samples and inspects the molded product, and manually adjusts the die height based on the inspection result.

  For example, a forging press that automatically adjusts the die height, such as that of Patent Document 1, is also known. In this forging press, a die temperature sensor that measures the die temperature, a frame temperature sensor that detects the frame temperature, a slide temperature sensor that detects the slide temperature, etc., and a die height adjustment by a detection signal from this temperature sensor And a control unit that performs control.

Japanese Patent Application Laid-Open No. 2003-311496

  However, in the thing of the said patent document 1, you have to add a temperature sensor for exclusive use. In addition, when the temperature change of each part of the press becomes relatively stable, the other factors such as die wear are larger than the temperature change of each part as a factor affecting the accuracy of the molded product. It is necessary to switch the control according to the passage of time etc. because it is more accurate to actually measure any of the weight or thickness, and the gap between molds, etc., and to perform feedback control based on this actual molding load There is a problem that the control becomes complicated.

  This invention is made | formed in view of this point, The place made into the objective is to adjust a die height appropriately with a simple structure, and to be able to obtain a forging with high finishing precision.

  In order to achieve the above object, according to the present invention, the die height is adjusted by utilizing the fluctuation of the load detected by the load sensor that is normally provided in the normal forging press.

Specifically, the forging press of the first invention is
A press body that moves the slide up and down and stamps the workpiece;
A load sensor that measures the load applied to the workpiece by stamping the slide;
A die height adjustment mechanism for adjusting the die height by adjusting the height of the slide;
A programmable logic controller that controls the die height adjustment mechanism based on the variation of the load sensor;
The programmable logic controller stores a reference load of the load detected by the load sensor, compares the reference load with an actual molding load measured by the load sensor, and a difference between the two is within a predetermined range. When outside, the die height adjusting mechanism is controlled so as to be within a predetermined range.

  That is, in the forging press, in the continuous production of workpieces, the molding load gradually increases or decreases due to the influence of the mold temperature and the mold lubricant. According to the above configuration, the reference load and the actual molding load measured by the load sensor are compared, and the die height adjustment mechanism is controlled so as to be within a predetermined range. Therefore, the control is simple and reliable. An appropriate die height adjustment is performed. Moreover, since a load sensor that is generally provided as a standard may be used, it can be introduced by simply rewriting the program of the programmable logic controller with respect to the conventional equipment.

In the second invention, in the first invention,
A press body that moves the slide up and down and stamps the workpiece;
A load sensor that measures the load applied to the workpiece by the slide;
A die height adjustment mechanism for adjusting the die height by adjusting the height of the slide;
Preparing a forging press with a programmable logic controller for controlling the die height adjustment mechanism based on the variation of the load sensor;
A reference load value storing step for storing a reference load of the load detected by the load sensor;
A measurement step of measuring a load applied to the workpiece by the load sensor when the slide is lowered to press-mold the workpiece;
A die height raising step of adjusting the die height adjustment mechanism to increase the die height when the actual molding load measured by the load sensor becomes larger than a value obtained by adding the first threshold to the reference load;
A die height reducing step of adjusting the die height adjusting mechanism to lower the die height when the actual molding load measured by the load sensor becomes smaller than a value obtained by subtracting the second threshold value from the reference load.

  Even in the above configuration, it is only necessary to compare the reference load and the actual molding load measured by the load sensor and control the die height adjustment mechanism so as to be within a predetermined range, so that the control is simple and reliable. An appropriate die height adjustment is performed. Moreover, since a load sensor that is generally provided as a standard may be used, it can be introduced by simply rewriting the program of the programmable logic controller with respect to the conventional equipment. In particular, it is possible to prevent frequent operation of the die height adjusting mechanism by controlling the reference value applied to the workpiece with a slight width.

  As described above, according to the present invention, the reference load of the load detected by the load sensor is compared with the actual molding load measured by the load sensor, and the die height is adjusted by controlling the die height adjustment mechanism. As a result, it is possible to appropriately adjust the die height with a simple configuration and obtain a forged product with good finishing accuracy.

FIG. 4 is an enlarged cross-sectional view of a portion I in FIG. 3. It is sectional drawing which shows the outline | summary of a structure of the forge press which concerns on embodiment of this invention. It is sectional drawing cut with another cross section which shows the outline | summary of a structure of the forge press which concerns on embodiment of this invention. It is a schematic diagram which shows the principal part sectional drawing of a forge press, and the hydraulic circuit of a hydraulic control part. It is a flowchart which shows the outline | summary of the die height adjustment method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  2 and 3 show a forging press 10 according to an embodiment of the present invention, and the forging press 10 is a mechanical hot forging press. For example, the forging press 10 is provided so that the slide 1 to which a die (not shown) is attached and the bolster 2 are opposed to each other vertically in the frame 3. The forging press 10 is configured such that the slide 1 connected to the crankshaft 4 that is rotationally driven by the connecting rod 5 moves up and down. The connecting rod 5 fitted to the outer periphery of the eccentric portion of the crankshaft 4 is inserted into the wrist pin 15 on the lower side, and the wrist pin 15 supports the slide 1 so as to suspend it. A flywheel 8 that is rotationally driven by a belt 7 by a main motor 6 is connected to one end side of the crankshaft 4 via a clutch 9. A brake device 11 that stops rotation of the crankshaft 4 and stops the slide 1 is attached to the crankshaft 4. The forging press 10 drives the flywheel 8 to rotate at a constant speed by the main motor 6, engages the clutch 9, and transmits the rotation of the flywheel 8 to the crankshaft 4 to raise and lower the slide 1 for forging. It is configured. As described above, the slide 1 is restrained in the left-right direction and the front-rear direction by the frame 3, and exhibits a forging effect by moving up and down while sliding on the inner surface of the frame 3 under the rotation of the crankshaft 4. .

  As shown in FIG. 1, a hydraulic operation unit 20 as a die height adjusting mechanism that adjusts the die height H by adjusting the height of the slide 1 is mounted on one rear surface of the slide 1. The rotating block 21 is attached to the eccentric shaft portion 15a of the wrist pin 15 by a bolt (not shown) so as to move integrally. The hydraulic operation unit 20 and the rotation block 21 are connected by a tilt rod 23. Both ends of the tilting rod 23 are rotatable, and the linear motion at one end of the tilting rod 23 is smoothly converted into an arc motion at the other end, which appears as an action for moving the shaft support portion of the slide 1 up and down. ing.

  Then, the arc motion of the rotation block 21 induces the rotation action of the wrist pin 15 mounted integrally, and the eccentric amount e between the axis P of the wrist pin and the axis Q of the eccentric shaft portion (FIG. 4). It appears as an action of moving the shaft support portion of the slide 1 up and down by the amount of vertical movement of the arc motion having a radius of (shown only in FIG. 5).

  One embodiment of the hydraulic actuator 20 and the hydraulic controller 30 of the present invention is shown in FIG. A piston 24 is slidably inserted into a cylinder 22a projecting from the slide 1 in the hydraulic operating unit 20, and the cylinder 22a is divided into a large hydraulic chamber 25 and a small hydraulic chamber 26, and both chambers 25, 26 are separated. Pipe lines 25a and 26a for supplying and discharging hydraulic oil are connected to each other. Although not shown in detail, the hydraulic control unit 30 is a combination of a hydraulic pressure source and various members for adjustment thereof (for example, see Japanese Patent No. 295888).

  In the present embodiment, the piston 24 linearly moves left and right by the action of the hydraulic circuit, and this linear motion is smoothly converted into an arc motion of the rotating block 21. Further, the rotating block 21 performs an arc motion, The slide 1 supported by the wrist pin 15 suspended and supported by the rotation of the eccentric shaft portion 15a of the wrist pin 15 has an eccentricity amount e between the shaft center P of the wrist pin 15 and the shaft center Q of the eccentric shaft portion 15a as a radius. As a result, it is possible to adjust the bottom dead center to an arbitrary position by moving up and down by the vertical distance of the arc trajectory.

  The forging press 10 includes a plurality of sensors that detect operating conditions. Further, the forging press 10 includes a PLC 41 as a programmable logic controller that analyzes the operation state based on information from a plurality of sensors and controls the forging press 10. For example, the PLC 41 may be connected to the monitoring PC 42 and configured to be able to display operating conditions such as load, die height H, and the like analyzed by the PLC 41 on the monitor of the monitoring PC 42.

  The forging press 10 includes a load sensor 43 made of a strain gauge or the like that applies a load applied to the workpiece. The strain gauge is affixed to a necessary portion of the forging press 10. For example, as shown in FIG. 1, the value of the load sensor 43 is collected by a load meter 43 a and sent to the PLC 41. A load applied to the workpiece can be detected from values from a plurality of strain gauges and the like. The movement amount of the piston 24 can be directly detected by the piston displacement sensor 44.

  Next, a method for adjusting the die height including the operation of the PLC 41 in the present embodiment will be described.

  First, in the preparation step, the forging press 10 described above is prepared.

  Further, as a reference load value storage step, a reference load F0 of a load detected by the load sensor 43 is stored in the PLC 41. The method for storing the reference load F0 is not particularly limited. For example, if the automatic correction mode is first turned off, the load reference collection mode is turned on and production is started, and then the automatic correction mode is switched to the automatic correction mode. Monitoring can be started with the average of the measured loads as the reference load F0.

  Then, as shown in FIG. 5, in step S01, press molding is performed for each workpiece.

  Next, in the measurement process of step S02, the load applied to the workpiece is measured by the load sensor 43 when the slide 1 is lowered and the workpiece is press-molded. As described above, this load may be determined from the values of the plurality of load sensors 43.

  Next, in step S03, when the actual molding load measured by the load sensor 43 becomes larger than the value obtained by adding the first threshold value α to the reference load F0, the process proceeds to step S04, and the hydraulic actuator 20 is adjusted to adjust the die height. Increase H. Specifically, the hydraulic circuit is switched, the hydraulic oil is poured into the small hydraulic chamber 26, and the piston 24 is slid in the direction of the large hydraulic chamber 25, so that the slide 1 is slightly raised and the die height H is raised. Thereby, the load added to a workpiece | work falls. Since the movement amount of the piston 24 can be directly measured by the piston displacement sensor 44, precise control can be performed. Further, for example, the first threshold value α and the second threshold value β described later may be adjusted based on the die height value geometrically calculated from the piston displacement sensor 44.

  When the value is equal to or smaller than the value obtained by adding the first threshold value α to the reference load F0, the process proceeds to step S05.

  In step S05, when the actual molding load measured by the load sensor 43 becomes smaller than the value obtained by subtracting the second threshold value β from the reference load F0, the process proceeds to step S06, the hydraulic actuator 20 is adjusted, and the die height H is adjusted. make low. Specifically, the hydraulic circuit is switched, the working oil is poured into the large hydraulic chamber 25, and the piston 24 is slid in the direction of the small hydraulic chamber 26, so that the slide 1 is slightly lowered and the die height H is reduced. As a result, the load applied to the workpiece increases.

  This operation is repeated every time the workpiece is pressed.

  As described above, normally, in the forging press, in the continuous production of workpieces, the molding load gradually increases or decreases due to the influence of the mold temperature and the mold lubricating liquid. Since the load F0 and the actual molding load F measured by the load sensor 43 are compared and the hydraulic actuator 20 is controlled so as to be within a predetermined range, the control is simple and surely appropriate. Die height adjustment can be performed.

  In addition, since the load sensor 43 that is generally provided as a standard may be used, there is an advantage in that the load can be introduced simply by rewriting the program of the PLC 41 with respect to the conventional equipment.

  Furthermore, it is possible to prevent the hydraulic operation unit 20 from being frequently operated by controlling the reference value applied to the workpiece with a slight width.

  As described above, according to the present embodiment, the die height H can be appropriately adjusted with a simple configuration, and a forged product with good finishing accuracy can be obtained.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use. The present invention can be applied to any of hot forging, warm forging, and cold forging.

1 slide
2 Bolster
3 frames
4 Crankshaft
5 Connecting rod
6 Main motor
7 Belt
8 Flywheel
9 Clutch
10 Forging press
11 Brake device
15 wrist pin
15a Eccentric shaft
20 Hydraulic actuator (die height adjustment mechanism)
21 Rotating block
22a cylinder
23 Tilt rod
24 piston
25 Large hydraulic chamber
25a, 26a pipeline
26 Small hydraulic chamber
30 Hydraulic control unit
41 PLC
42 Monitoring PC
43 Load sensor
43a load cell
44 Piston displacement sensor

Claims (2)

A press body that moves the slide up and down and stamps the workpiece;
A load sensor that measures the load applied to the workpiece by stamping the slide;
A die height adjustment mechanism for adjusting the die height by adjusting the height of the slide;
A programmable logic controller that controls the die height adjustment mechanism based on the variation of the load sensor;
The programmable logic controller stores a reference load of the load detected by the load sensor, compares the reference load with an actual molding load measured by the load sensor, and a difference between the two is within a predetermined range. A forging press characterized by being configured to control the die height adjusting mechanism so as to be within a predetermined range when outside. A press body that moves the slide up and down and stamps the workpiece;
A load sensor that measures the load applied to the workpiece by the slide;
A die height adjustment mechanism for adjusting the die height by adjusting the height of the slide;
Preparing a forging press with a programmable logic controller for controlling the die height adjustment mechanism based on the variation of the load sensor;
A reference load value storing step for storing a reference load of the load detected by the load sensor;
A measurement step of measuring a load applied to the workpiece by the load sensor when the slide is lowered to press-mold the workpiece;
A die height raising step of adjusting the die height adjustment mechanism to increase the die height when the actual molding load measured by the load sensor becomes larger than a value obtained by adding the first threshold to the reference load;
A die height reduction step of adjusting the die height adjustment mechanism to lower the die height when the actual molding load measured by the load sensor becomes smaller than the value obtained by subtracting the second threshold value from the reference load. Die height adjustment method for forging press.

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