JPH1015699A - Device for correcting die height of press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a correction precision by correcting according to these differences even when a difference in the thermal deformations of the left and the right frames of a press main body, occurs or a difference in the drift quantity of a detecting means installed on each die height correcting device, occurs. SOLUTION: On the side face of a press main body 1 with a mechanical system slide drive means 2, an auxiliary frame 5 whose lower end side is pivotaly mounted on the press main body and an upper end side is made a free end, is installed. A slide position detecting means 8 with a temperature detecting means 11 installed on the free end side of the auxiliary frame and a temperature detecting means 10, are installed. The position of a slide 3 and the temperatures of the auxiliary frame and the slide position detecting means, are detected respectively, and a slide is NC- controlled by the detected value of the slide position detecting means. And also, according to temperature change quantities obtained from differences in temperature among the auxiliary frame and the slide position detecting means and a preliminarily set standard temperature, the expansion and contraction quantity of the auxiliary frame and the drift quantity of the slide position detecting means are calculated, and a command value is corrected by adding or deducting a calculated result to or from the command value of the NC control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die height correcting device for a press which enables high-precision press working.

[0002]

2. Description of the Related Art Conventionally, a press machine has a vertically movable slide (or ram), and presses between an upper die mounted on the slide and a lower die mounted on a bolster (or bed). Is configured to do so. In the press machine as described above, the distance (die height) from the upper surface of the bolster to the lower surface of the slide is adjusted each time the mold changes. Adjusting this die height with high accuracy is a necessary step in performing highly accurate press working. is important.

However, even if the die height is accurately adjusted before the press working, if the frame and each part of the press thermally expand due to the temperature during the press working, the die height changes, so that high-precision press working cannot be performed.

[0004] In order to improve such a problem, an adjusting device and a correcting device for preventing the die height from being affected by a change in temperature are conventionally known, for example, from Japanese Utility Model Laid-Open No. 2-1599 and Japanese Utility Model Laid-Open No. 64-27200. Has been proposed.

The bottom dead center position correcting device disclosed in Japanese Utility Model Laid-Open Publication No. 2-1599 is provided with a temperature sensor for detecting the temperature of the press machine, and the temperature detected by the temperature sensor and the temperature of the press machine stored in advance are stored. By comparing the amount of change in the bottom dead center of the slide corresponding to, calculating the bottom dead center position correction amount corresponding to the temperature signal from the temperature sensor, and controlling the drive motor based on the calculation result, the bottom dead center of the slide is calculated. The position is corrected.

In the automatic die height adjusting apparatus disclosed in Japanese Utility Model Application Laid-Open No. 64-27200, a part of lubricating oil supplied from a lubricating oil pump to each part of the press body is supplied to an oil passage provided in an upright of the press body. Then, by extending the upright by the oil temperature, the reduction in die height due to the thermal expansion of each part of the press body is offset, and the die height is automatically adjusted.

However, the temperature of each part of the frame disclosed in the above publication is detected, and the position of the bottom dead center is corrected based on the detected value, or the upright is extended by the oil temperature to offset the decrease in die height. Has the following problems.

That is, since the frame is not a simple shape, it undergoes complicated thermal deformation. For this reason, even when the temperature at the measurement point is the same as in the above-mentioned publication, the amount of thermal deformation of the frame or the like is not always the same when the operation history or the processing conditions change, so that a correction error occurs. In addition, since the normal position sensor has a temperature drift, the output value changes due to changes in the use environment temperature and self-heating,
Even if control is performed based on the value detected by the position sensor, there is a problem that high-precision machining cannot be performed. The present invention has been made in order to improve such a conventional problem, and an object of the present invention is to provide a die height correction apparatus for a press that enables highly accurate press working by minimizing the influence of heat. It is.

[0009]

In order to achieve the above object, the invention according to claim 1 has a slide which can be moved up and down by mechanical slide driving means on an upper part of a press body, and In a press provided with a die height adjusting device for adjusting the die height of the slide by rotating the screw member forward and backward by a die height adjusting motor between the driving means and the slide, at least one side surface of the press body has a lower end side. Is pivotally attached to the press body, an auxiliary frame having an upper end as a free end is provided, and a slide position detecting means and a temperature detecting means are provided on a free end side of the auxiliary frame, and the slide position detecting means detects The die height adjustment motor is NC controlled based on the detected value, and the temperature of the auxiliary frame detected by the temperature detecting means is detected. And the amount of expansion and contraction of the auxiliary frame and the amount of drift of the slide position detection means based on the temperature of the slide position detection means detected by the other temperature detection means and the temperature change amount obtained from a temperature difference between a preset reference temperature. The calculated and obtained value is added to or subtracted from the command value of the NC control to correct the command value.

With the above structure, the die height adjustment motor is controlled by the NC device based on the slide position detection value detected by the slide position detection means, and the temperature of the auxiliary frame supporting the slide position detection means is detected to determine the amount of expansion and contraction of the auxiliary frame. Is calculated, and the obtained value is added to or subtracted from the command value of the NC device for controlling the vertical movement of the slide, so that the command value is corrected. Therefore, the temperature during press working and the temperature of the press body change. However, since the die height does not fluctuate, high-precision pressing can be performed.

Further, since the slide position detecting means is provided between the free end side of the auxiliary frame and the slide, the press load changes depending on the work to be processed, thereby changing the elongation and the opening amount of the frame of the press body. However, since the position of the slide can be detected without being affected by these factors, it is not necessary to perform a complicated operation such as adjusting the slide adjustment device every time the press load changes as in a conventional mechanical press. Press working becomes possible.

According to a second aspect of the present invention, a temperature detecting means is provided to the slide position detecting means.

According to the above configuration, even if the output value of the slide position detecting means changes due to a change in the use environment temperature or a drift due to self-heating, the correction can be performed without being affected by the temperature drift. improves.

According to a third aspect of the present invention, a press frame is provided with a plurality of correction frames, slide position detecting means, and temperature detecting means, and the correction value obtained by these means is applied to the press body. A plurality of die height adjustment devices provided are separately corrected.

According to the above configuration, even if there is a difference in the thermal deformation of the left and right frames of the press body or a difference in the drift amount of the detecting means provided in each die height correction device, it is possible to perform correction according to the difference. Therefore, the correction accuracy can be improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a press having a C frame will be described in detail with reference to the drawings shown in FIGS. FIG. 1 is a side view of a press body provided with a die height correction device, and FIG. 2 is a flowchart showing the operation of the die height correction device.

In FIG. 1, reference numeral 1 denotes a press body in which C frames 1a are arranged on both sides, and a mechanical slide driving means 2 comprising a crank mechanism on an upper part, and a die height adjusting device 3
Is provided.

The slide drive means 2 has a connecting rod 2a for converting the rotation of a crankshaft (not shown) into reciprocating movement. The upper end of a plunger 2b which can move up and down is pivotally connected to the connecting rod 2a by a pin 2c. Is being worn.
A slide 4 is connected to a lower end of the plunger 2b via a die height adjusting device 3.

The die height adjusting device 3 includes a slide 4
The first stage gear 3d of the gear train 3c is fixed to a rotating shaft 3b of the die height adjusting motor 3a. The final stage gear 3e of the gear train 3c is fixed to the lower end of a screw member 3f screwed from below into the center of the plunger 2b, and is connected to the screw member 3f by the die height adjusting motor 3a via the gear train 3c. The forward / reverse rotation allows the die height DH to be adjusted.

On the other hand, an upper die is attached to the lower surface of the slide 4, and a lower die (both not shown) is provided on a bolster 1c installed on the bed 1b. Accordingly, press working is performed between the upper die and the lower die.

An auxiliary frame 5 having substantially the same shape as the opening is provided near the opening of the C frame 1a constituting the press body 1. The lower end of the auxiliary frame 5 is pivotally attached to the side surface of the C frame 1a by a pin 6,
A slide position detecting means is provided between the free end side and the rear end of the slide 4 by a linear sensor between the free end side and the rear part of the slide 4. 8 are provided.

The slide position detecting means 8 is a slide 4
, And a sensor head 8b fitted to the sensor rod 8a and fixed to the auxiliary frame 5 side, and the sensor rod 8a moves up and down together with the slide 4. Thus, the position of the slide 4 can be detected by the sensor head 8b. The position signal detected by the slide position detecting means 8 is N (not shown).
It is taken into the C device, and the die height adjusting motor 3a is NC-controlled based on this position signal.

On the other hand, a temperature detecting means 10 for detecting the temperature of the auxiliary frame 5 is provided on the linear portion on the free end side of the auxiliary frame 5, and a temperature detecting means for detecting the temperature of the sensor head 8b is provided on the sensor head 8b. Means 11 are provided. The temperature of the free end side of the auxiliary frame 5 and the temperature of the sensor head 8b detected by the temperature detecting means 10 and 11 are taken into the NC device, and a reference temperature detected and set in advance is set by the NC device. These differences are determined by comparison, and the amount of drift of the slide position detecting means 8 due to the temperature and the amount of expansion and contraction of the auxiliary frame 5 are calculated based on the obtained amount of temperature change, and the calculation results are fed back to the NC control. , NC control is corrected based on the calculation result.

Next, the operation will be described with reference to the drawing shown in FIG. 2. The distance from the upper surface of the bolster 1c to the lower surface of the slide 3, that is, the variation ΔDH of the die height DH is determined by the sensor of the slide position detecting means 8 from the upper surface of the bolster 1c. Head 8
The amount of change of the distance SH to b is equal to △ SH, but the drift amount due to the temperature of the slide position detecting means 8 appears as an error. Further, it is difficult to directly detect the amount of change ΔDH of the die height DH from the connection of a mold or the like. Then, since the change amount ΔSH of the distance SH to the sensor head 8b is determined by the thermal expansion, the temperature of the auxiliary frame 5 is measured and ΔS
H, and the temperature drift of the sensor head 8b ΔH
H is converted from Δt, and the total drift (ΔDD = ΔSH
+ ΔHH) is fed back to the NC control to offset (correct) the ΔDD component.

[0025] To describe the actual correction method in the flowchart shown in FIG. 2, the sensor head 8b in Step S ₁
When There completed homing, the temperature detecting means 1 in step S ₂
0,11 by the auxiliary frame 5 temperature (To) and reads the temperature (to) of the sensor head 8b, followed by a temperature up to Step S ₃ example 10 minute intervals (Tn), reads the (tn). And proceeds to step S ₄ | Tn- (Tn-
1) | or | tn- (tn-1) | a determination is ≧ 2 ° C., which was judged to be abnormal if there is a rapid temperature increase and decrease in the case of "YES", the process proceeds to Step S ₅ Emergency stop of press. In the case of "NO" the program proceeds to step S ₆ that there is no abnormality, Tn-the To and tn
The -to calculate, further at step S ₇ and Step S ₈ △ SHn, calculates the △ HHn and △ DDn.

The calculation of △ DDn is as follows. (1) ΔDDn = ΔSHn + ΔHHn Thermal expansion of auxiliary frame 5 ΔSHn = 11 × 10 ⁻⁶ × L × (Tn−To) mm Note that 11 × 10 ⁻⁶ is the linear expansion coefficient of auxiliary frame 5, L is bolster 4 Distance from upper surface to sensor head 8b (mm) (2) Drift of slide position detecting means 8 ΔHHn = [− 0.0034 + 16 × 10 ⁻⁶ × ST] ×
(Tn-to) ST is the stroke of the sensor head 8b. (3) ３DDn is from the above (1) and (2), ΔDDn = [− 0.0034 + 16 × 10 ⁻⁶ × ST] ×
(Tn-to) + 11 × 10 ⁻⁶ × L × (Tn-To)

Then, the drift amount △ DDn obtained by the above calculation is compared with the allowable error in step S9, and △ DD
If n ≧ 0.003 mm, the operation proceeds to step S10; otherwise, the operation is continued (0.003 mm
Is the error tolerance).

The auxiliary value obtained by the above equation is fed back to the NC unit, and the NC value of the die height adjusting motor 3a is adjusted.
Step S ₁₀ by adding to the bottom dead center command value of the control.
Is used to correct the NC control. Although the above calculation is performed when the detection data of the sensor head 8b increases upward, the signs are reversed when the detection data is mounted so as to increase downward. That is, △ HHn becomes-△ HHn. The above calculation shows an algorithm for measuring two points of temperature. However, if it is confirmed by a preliminary test that tn and Tn are substantially the same, it is also possible to set tn = Tn and set the temperature input to one point.

In the above embodiment, the temperature of the slide position detecting means 8 is detected by the temperature detecting means 11 to perform drift correction. However, in the case of a position detecting means having no or extremely small temperature drift, this correction is performed. This correction is not necessary if it is not necessary, and if the slide position detecting means 8 can be maintained at a constant temperature by providing a heat sink or the like. In addition, although the auxiliary frame 5 is formed in a plate shape, a pipe, a round bar, a square bar, or the like may be used as long as it has a relatively simple shape with no hysteresis in the amount of expansion / contraction with respect to temperature in a temperature rise / fall cycle. Further, the auxiliary frame 5 is replaced with one C frame 1
Although provided on the side surface a, when the slide 4 is large, a pair of left and right may be provided, or one may be provided at the center of the slide 4, and the temperature of the slide 4 and the bolster 1c is also detected and corrected. By doing so, the accuracy is further improved.

The embodiment described above is applied to the press body 1 having the C frame 1a. However, the present invention can be similarly applied to a straight side press having the mechanical slide driving means 2 shown in FIGS. It is.
In the straight side press, as shown in FIG. 3, a linear frame 1a 'is erected on a bed 1b so as to be separated from each other in the left-right direction, and a crown 1d is suspended between upper portions of the frames 1a'. The bed 1b and the crown 1d are fastened by a tie rod 12 inserted into the frame 1a '.

A die height adjusting device 13 shown in FIGS. 4 and 5 is provided between the mechanical slide driving means 2 and the slide 4 housed in the crown 1d. The die height adjusting device 13 includes a die height adjusting motor 13a.
The synchronous shaft 13d is rotated by the die height adjusting motor 13a via the gears 13b and 13c. For example, two ends of the synchronous shaft 13d are provided at the upper portion of the slide 4 at two places, for example. Worm gear 13e is provided at both ends.

The worm gear 13e is connected to the worm wheel 1 spline-engaged with the screw member 13f.
3g, and the upper end side of the screw member 13f is screwed into the plunger 2b of the slide driving means 2 from below, and is driven by the die height adjustment motor 13a.
By simultaneously rotating the screw members 13f provided at the left and right points 15, the die height DH of the slide 4 is increased.
Can be adjusted.

On the other hand, according to the die height correcting apparatus of the present invention, an auxiliary frame 5 is provided on a frame 1a 'provided between the bed 1b and the crown 1d of the press body 1 as in the case of the C frame 1a. 5, the slide position detecting means 8 and the temperature detecting means 10 may be provided on the free end side, and the temperature detecting means 11 may be provided on the sensor head 8b of the slide position detecting means 8. Since it is the same as the case of the press having 1a, its description is omitted.

In the above embodiment, the die height adjustment motor 13a simultaneously drives the die height adjustment devices 13 provided at the left and right points 15 via the synchronous shaft 13d to adjust the die height DH. In the case of a straight side press in which the left and right die height adjustment devices 13 are driven by independent die height adjustment motors 13a as shown in FIG.
a ', the auxiliary frame 5
Position detecting means 8 and temperature detecting means 10
And the sensor head 8b of the slide position detecting means 8.
The temperature detecting means 11 is installed in the apparatus.

When the correction value is calculated in the same manner as in any of the above embodiments, the NC control of the left die height adjustment motor 13a is corrected by the correction value obtained by the left die height correction device, and the right die height correction device is corrected. The N value of the left die height adjustment motor 13a is
Correct the C control. As a result, even if a difference occurs in the thermal deformation of the left and right frames 1a 'and a difference occurs in the drift amounts of the detection means 8 and 11 of the left and right die height correction device, correction can be performed in accordance with the difference. Improve further.

Although each of the above embodiments employs a crank mechanism for the mechanical slide drive means 2, it can be applied to all mechanical presses employing the link mechanism and other mechanical slide drive means 2. .

[Brief description of the drawings]

FIG. 1 is a side view of a press provided with a die height correction device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the die height correction device according to the embodiment of the present invention.

FIG. 3 is an explanatory view showing an embodiment in which the die height correcting device of the present invention is applied to a straight side press having a mechanical slide driving means.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6 is an explanatory diagram showing an embodiment in which the die height correction device of the present invention is applied to a straight side press having a die height adjustment device provided with an independent die height adjustment motor for each of a plurality of points.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Press body 1a ... C frame 2 ... Slide drive means 3, 13 ... Die height adjustment device 3a, 13a ... Die height adjustment motor 3f, 13f ... Screw member 4 ... Slide 5 ... Auxiliary frame 8 ... Slide position detection means 10 ... Temperature detection Means 11: Temperature detection means

Claims (3)

[Claims] 1. A press 4 having a slide 4 which can be moved up and down by a mechanical slide drive means 2 on an upper portion of a press body 1, and a screw member 3f provided between the slide drive means 2 and the slide 4 by a die height adjusting motor 3a. In the press provided with the die height adjusting device 3 for adjusting the die height of the slide 4 by rotating the front and rear sides, the lower end side is pivotally attached to at least one side surface of the press main body 1 to the press main body 1, An auxiliary frame 5 having a free end on its side is provided, and a slide position detecting means 8 and a temperature detecting means 10 are provided on a free end side of the auxiliary frame 5, and the die height is determined based on a detection value detected by the slide position detecting means 8. In addition to performing NC control on the adjusting motor 3a, the temperature of the auxiliary frame 5 detected by the temperature detecting means 10 and a preset reference temperature The amount of expansion and contraction of the auxiliary frame 5 and the slide position detecting means 8 are based on the temperature change amount obtained from the
A die height correction device for a press, wherein the drift amount is calculated and the obtained value is added to or subtracted from the NC control command value to correct the command value. 2. The die height correcting device for a press according to claim 1, wherein the slide position detecting means 8 is provided with a temperature detecting means 11. 3. A plurality of auxiliary frames 5, slide position detecting means 8 and temperature detecting means 10 are installed on the press body 1, and a plurality of die height adjustments provided on the press body 1 are adjusted by the correction values obtained by these means. 3. The die height correcting device for a press according to claim 1, wherein the device is corrected separately.