JPH02303645A - Press machine and its polling reduction dimension control method - Google Patents

Abstract

PURPOSE:To shorten the cogging time by measuring a relative relation position of a ram and rolling reduction pressure of a rolling reduction stroke, estimating the deformation quantity by its stroke and correcting automatically rolling reduction dimensions. CONSTITUTION:A beam 54 is depressed by a hydraulic piston 59 and the upper ram 52 is depressed through a column 51. Subsequently, the upper ram 52 is brought close to the lower ram 53 and a material to be cogged is compressed. Next, an inter-ram distance H is measured by an encoder 56. Thereafter, a relative relation position of the rams 52, 53 and rolling reduction pressure of a rolling reduction stroke are measured. In a stage that a measured value is equal to (cogging target dimensions - (a predictor of overrun being the deformation quantity and the rolling reduction of a driving ram of an ascending signal)) or exceeds it, an ascent command signal is generated by a dimension setting block. That is, the deformation quantity by the stroke is estimated, and rolling reduction dimensions are corrected automatically. In such a way, the reliability of cogging dimensions can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a press machine that repeats a reduction stroke at a high speed with a substantially constant or gradually changing pressure during hot forging work, and a method for controlling the reduction dimension thereof. It is something.

[Conventional technology]

When forging a large square steel material into a small square steel material, the material to be forged is drawn at approximately the same rate from the first forging and stretching stroke at one end of the material to the last forging and stretching stroke at the other end. Forging is performed by a reduction stroke with a substantially constant pressure while feeding in the longitudinal direction. Further, when a cone-shaped ingot is forged into a rectangular bar with a predetermined cross-sectional size, the rolling pressure gradually changes to increase or decrease gradually. This kind of work is done in most cases with open type press machines called free forging.

Also, like other processing machines, press machines deform main structural parts such as columns due to pressure reaction force. In order to manufacture products with the correct dimensions, it is possible to directly measure and control the H dimension shown in Figure 4, but since the equipment for this interferes with the forging work, in reality it is necessary to use actuators such as hydraulic cylinders. A means for measuring the dimensions at that time is provided nearby. In this case, it is necessary to compensate for the amount of deformation from this measuring means to the front ram.

The usual compensation method is to detect the load at that time and estimate the amount of deformation at that time using K (t/m) corresponding to a predetermined spring constant or a load vs. deformation curve, and then Methods are known to compensate for.

However, in the forging operation described above, the rolling cycle is short,
Due to the dynamic characteristics of the ram, a control method is adopted in which a command signal for raising the ram is issued before the ram reaches its lowest point (the phenomenon or amount of downward movement of the ram after the command signal for raising is hereinafter referred to as overrun). .

Therefore, the above-mentioned dimension compensation method cannot be adopted. In the present invention, high speed refers to a state where a ram rise signal is issued before the ram reaches the lowest point, that is, a state of control accompanied by overrun, as described above. means.

Conventionally, each time the forging surface, that is, the forging conditions change, the pressurizing force P applied to the forging surface in the first reduction stroke is measured by measuring the pressure of hydraulic oil, etc., and then the upper and lower parts shown in Fig. 4 are The state in which the ram 2.3 was in contact and the pressing force was applied was set as the reference point 0 for dimension measurement. Therefore, from now on until the reference point is changed as described above, correct dimensional control is performed with the pressurizing force P applied.

[Problem to be solved by the invention]

The present invention provides a reduction dimension control dimension that effectively and automatically compensates for errors due to deformation of the press when repeating reduction strokes with substantially constant or gradually changing pressure at high speed, and a press machine equipped with this function. The purpose is to

[Means to solve the problem]

The present invention provides an inter-ram dimension measuring block that measures the relative position between a member connected to one ram and transmitting the rolling pressure and the other ram or a member connected to the other ram and transmitting the rolling pressure. , a rolling pressure measuring block and a forging target for measuring the rolling pressure of the rolling stroke and estimating the amount of deformation of the member from the relative position measuring section to the front ram of the press during the rolling pressurization based on this; In a predetermined reduction stroke after the reduction stroke, the measured value by the ram dimension measurement block is (the forging target dimension - (the deformation amount and the overrun amount which is the reduction amount of the drive ram after the raising command signal). A press machine characterized in that it is equipped with a sizing block that generates the raising command signal when the expected value is equal to or exceeds the expected value), and repeats the lowering stroke at a substantially constant or gradually changing pressure at high speed. In a method for controlling the reduction dimension of a press machine, the reduction pressure of the reduction stroke is measured, the amount of deformation of the press machine is estimated based on this, and the reduction dimension of a predetermined reduction stroke after the stroke is automatically determined based on this result. This is a method for controlling the reduction dimension of a press machine, which is characterized in that the reduction dimension is corrected.

[Effect]

As described above, the present invention measures the rolling pressure at a certain rolling stroke, estimates the amount of deformation of the portrait part at that stroke (hereinafter referred to as the amount of deformation), and applies this to the stroke immediately after that stroke. The reduction dimension is compensated by directly reflecting it or by distributing and reflecting it in the subsequent predetermined reduction stroke. Therefore, the distance use of the present invention is not limited to repeated strokes with almost constant pressure;
It can be applied to cone-shaped ingots or materials with gradually expanding and decreasing cross-sectional dimensions or products with such finished dimensions.

〔Example〕

Next, the present invention will be explained based on drawings of embodiments.

FIG. 4 shows the main structure of a hydraulic press to which an embodiment of the present invention is applied. In rolling down, the beam 54 is pushed down by the hydraulic piston 59 to push down the upper ram 52 via the column 51, and the upper ram 52 approaches the lower ram 53, so that the material to be forged (not shown) is compressed. It has become. The distance H between the rams is measured by determining the relative movement between the lower plate 55 and the column 51 by using the encoder 56: aJ. That is, it engages with the rack 57 fixed to the lower plate 55, and the column 51
The rotary encoder 56 detects the rotation of the pinion 58 supported by the rotary encoder 56. Therefore, this detected value includes the amount of deformation of the press machine. The pressing force of the press is determined by measuring the pressure of hydraulic oil using a pressure converter 60 and converting it into an electrical quantity.

Next, the control method and operation of the press machine of the present invention will be explained with reference to FIG.

FIG. 1 is a block diagram of a control system applied to this embodiment.

First, in the ram-to-ram dimension measuring block, by counting the pulses generated by the pulse generator 11, which is the encoder mentioned above, with the counter 12, the pulses corresponding to the 8 dimensions in FIG. It is converted into a signal including an error due to the deformation, and outputted to the dimension setting block-2- and the elevation position setting block-nose, which will be described later, as well as to the register 13.

The register 13 monitors this signal, finds the minimum value LL during one cycle, holds it until LL of the next cycle is output, and outputs it to the display 14 for display.

Next, the content LL of this register, that is, the minimum value in the previous rolling cycle, is stored in the overrun correction detection block soil as the target forging dimension FD of the mechanical system, which will be described later. The difference D=FD-LL between the two is calculated here. This difference is mainly based on the difference between the actual overrun and its expected value. In this embodiment, in order to prevent the forged product from having a negative dimension, half of the difference is determined by the overrun correction value O set in the open run change block.
It is added to the RC (as a modified overrun estimate) and input to the dimensioning block master and the lift positioning block master.

The reduction pressure correction unit 27 that characterizes the present invention receives the outputs of the existing pressure gauge 25 and the pressure gauge 26,
It consists of a converter 26 and a subtracter 22 that estimate the maximum amount of deformation during one cycle based on the load versus deformation curve of the press, and temporarily store that value until the next time it is output.

Dimension setting block or first, set values set in the forging target dimension setting device 21 and the converter 2 of the reduction pressure correction section 27
The deformation amount estimated value temporarily stored in 6 is input to the subtracter 22 to obtain the difference FD.

At this time, the estimated amount of deformation may be obtained by inputting the entire amount of data from the immediately preceding rolling cycle into the immediately following rolling cycle;
This FD may be distributed to a plurality of subsequent reduction cycles and input to the subtracter 22. This FD is displayed on the display, and is output to the overrun correction detection block ± as described above, and is added to the subtracter 22. It is input to the unit 23 together with the corrected overrun expected value which is the output from the overrun change block master and is added thereto. That is, this addition result is the forging target dimension - deformation amount + corrected overrun expected value.Finally, the comparator 24 calculates the above-mentioned addition result based on the above-mentioned ram dimension measurement system. The measured value of the dimension between the rams at every moment during the reduction stroke is compared and monitored, and an upward command signal is generated when the measured value of the dimension between the rams is equal to or less than the above-mentioned addition result.

In response to this raise command signal, the control valve of the hydraulic system begins to switch from the previous lowering operation position to the neutral position and then to the raising position, and therefore, the upper ram 2 continues to lower for a while (overrun) and then starts to rise. do.

Note that the ascending position setting block 3
The position of the stroke is monitored every moment, and when the set stroke is reached, it operates to issue a descending command signal.

FIGS. 2 and 3 illustrate the present invention and the operating conditions over time prior to modification, respectively, and will now describe the present invention in further detail.

In both figures, this press machine operates based on the electric command shown in A, and at the time of the command transmission position, the position of the upper ram 52 that is rising when lowering is the target forging dimension FD of the mechanical system or When the command reaches the position where stroke R3 is added to FD'(FD': the target forging dimension of the mechanical system in conventional machines), a command is issued, and the upper ram 52 is activated during the switching operation of the control valve and when it finishes rising due to inertial force. Heading down.

Regarding the ascent, the position of the upper ram 2 during descent is determined by the overrun correction value ○ to the target forging dimension FD or FD' of the mechanical system.
When the value obtained by adding RC is reached, a rising command is generated, and the upper ram 52 starts rising during the switching operation of the control valve and when it finishes descending due to inertial force.

At this time, the lowest point dimension of the press where the ram begins to rise gradually approaches the target forging dimension FD or FD' of the mechanical system, however, FD (the target forging dimension of the mechanical system in this example) is , the values for subsequent reduction strokes are corrected by taking into account the deformation of the structural part due to the reduction pressure during a certain reduction stroke. In contrast, the target forging dimension FD' of the mechanical system in the conventional method is a fixed dimension determined by the applied pressure reduction, and does not respond to changes in the reduction pressure.

〔Effect of the invention〕

Conventional methods require one pressure reduction and dimension setting based on this for each finished dimension.
According to the present invention, the reduction stroke is corrected from the second time using the pressing force of the first time, and no artificial correction is made from the first time, high-speed forging can be performed automatically, and the forging time can be shortened. In addition, the reliability of forging dimensions has been improved, and the extra thickness for preventing dimension minus defects, etc., can be reduced to 5M instead of the standard 9mm, which improves material yield and improves machine production. We were able to significantly reduce the number of man-hours required for target cutting and finishing.

Brief Description of the Drawings Fig. 1 is a block diagram of the control system of a press machine according to an embodiment of the present invention, and Fig. 2 is a diagram showing the command values of the press and the operating position (B) of the upper ram of the embodiment. , Figure 3 is a diagram showing the conventional press command value (A) and the operating position of the upper ram (B),
FIG. 4 is a diagram showing the main structure of the press machine.

1: Ram distance measurement block, 2: Dimension setting block,
l: Rising position setting block, ±niover run correction block, -base 11 overrun change block Fig. 2 Fig. 3

Claims (1)

[Claims] 1. An inter-ram device for measuring the relative position between a member connected to one ram and transmitting a reduction pressure and the other ram or a member connected to the other ram and transmitting a reduction pressure. a dimension measuring block, a rolling pressure measuring block that measures the rolling pressure of the rolling stroke and estimates the amount of deformation of the member from the relative position measuring section to the mouth ram of the press during the rolling pressurization based on this; The forging target dimension is set and the value measured by the ram dimension measuring block at a predetermined reduction stroke after the reduction stroke is (the forging target dimension - (the reduction amount of the drive ram after the deformation amount and the raising command signal). A press machine comprising a dimension setting block that generates the upward command signal when the expected overrun value is equal to or exceeds the expected overrun value. 2. In a method for controlling the reduction dimension of a press machine that repeats a reduction stroke with a pressure that is approximately constant or gradually changes at high speed, the reduction pressure of the reduction stroke is measured, and the amount of deformation of the press machine is estimated based on this, A method for controlling the rolling dimension of a press machine, characterized in that the rolling dimension of a predetermined rolling stroke after the stroke is automatically corrected based on this result. 3. The method for controlling the rolling dimension of a press machine according to claim 2, wherein the predetermined rolling stroke is a stroke immediately after the rolling stroke at which the rolling pressure was measured.