JPH0329034Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] This invention relates to a hydraulic folding machine.

[Prior art]

In a bending machine, it is necessary to accurately set the mold origin, which serves as a reference for the bending process, depending on the mold.

Conventionally, in hydraulic bending machines, the mold origin has been set by visually observing the cylinder pressure that presses the mold and detecting the position where the cylinder pressure rises to a predetermined value. There is.

However, since the cylinder pressure changes rapidly with respect to the mold interval, it is difficult to set the cylinder pressure.

Therefore, some attempts have been made to automatically detect the cylinder pressure and set the ram position when the hydraulic pressure reaches a predetermined value as the mold origin, but the previous attempts lacked consideration for the control device. However, there were problems such as the operation was time-consuming, the setting position was inaccurate, and there was a risk of mold damage.

[Purpose of invention]

The purpose of this invention is to improve the above-mentioned problems and provide a bending machine that can automatically set the mold origin more accurately and more safely.

[Summary of the idea]

In order to achieve the above object, this invention has a ram equipped with a mold for bending plate material, which is movable up and down on the upper or lower side of the frame, and a mold that cooperates with the mold. A ram position detecting section for detecting the vertical position of the ram in a bending machine comprising a supporting table fixed to the lower side or the upper side of the frame and a cylinder for moving the ram up and down. a servo valve that controls the drive of the cylinder to control the position and vertical movement speed of the ram; a servo valve control section that controls the servo valve; a pressure detector that detects the pressure of the cylinder; a pressure comparison unit that compares the set pressure and the pressure detected by the pressure detector and outputs a ram stop command to the servo valve control unit and an origin setting command when the two pressures become equal; The mold origin setting section sets the mold origin position based on the origin setting command of the pressure comparison section and the detection value of the ram position detection section.

〔Example〕

Embodiments of this invention will be described below with reference to the accompanying drawings.

First, to briefly explain the drawings, Fig. 1 is a side view of a folding machine according to an embodiment of this invention;
FIG. 2 is a block diagram of the control device, FIG. 3 is an explanatory diagram of a mold origin setting method, and FIG. 4 is an explanatory diagram showing the effect of mold origin setting.

As schematically shown in FIG. 1, the folding machine 1 includes:
A table supporting a lower mold 5a is attached to the lower part of the C-shaped frame 3, and on the upper side corresponding to this mold 5a, an upper mold (punch) is mounted on a ram 9 that is driven up and down by a cylinder 7. 5b.

The molds 5, 5a, and 5b are replaced as appropriate depending on the type of processing, and have different dimensions for each mold. Furthermore, the dimensions of the mold 5 are slightly different due to the re-polishing process.

On the other hand, an appropriate position detector such as an encoder device (hereinafter simply referred to as an encoder) 11 is provided to detect the vertical movement of the ram 9, and also supplies pressure fluid (oil) to the cylinder 7. Therefore, a hydraulic circuit 13 is provided.

The hydraulic circuit 13 includes a hydraulic pump 15, a pressure regulating valve 17 that adjusts the pressure by discharging the fluid supplied from the pump 15, and a pressure regulating valve 17 that applies an appropriate restriction to the pressure fluid supplied from the valve 17 and controls the cylinder 7. A servo valve 19 for supplying the air is provided.

Further, a pressure detector 21 is provided between the servo valve 19 and the cylinder 7 to detect the cylinder pressure or the pressure supplied to the cylinder 7.

Although the figure is shown in a simplified manner for ease of explanation, in reality, a larger number of control valves are connected to the hydraulic circuit 13, and not only an outgoing path but also an incoming path is formed, and furthermore, A plurality of them are provided in parallel with the mold depending on the length of the mold.

The encoder 11, pressure regulating valve 17, servo valve 19, and pressure detector 21 are connected to a control device 23 mainly composed of an NC device.

As shown in FIG. 2, the control device 23 includes a servo valve drive unit 25 as a member necessary for setting the mold origin.
, servo valve control section 27 , and ram position detection section 29
, mold data storage section 31 , and speed change command section 3
3, a position comparison section 35, a pressure comparison section 37, and a mold origin setting section 39.
In an actual NC device, many other means are required, such as a back gauge control means for regulating the bending position of the machine, but the details thereof will be omitted.

The servo valve control section 27 is connected to the servo valve drive section 25.
The valve opening degree of the servo valve 19 is controlled via a servo amplifier. Control is performed regarding the position and speed of the ram 9, and a feedback signal is obtained from the encoder 11 to output a command signal to the servo valve drive unit 25 so that the ram 9 moves to a predetermined position at a predetermined speed.

The ram position detection section 29 detects the current position of the ram 9, and includes a counter that integrates feedback pulses from the encoder 11.

The mold data storage section 31 stores dimensional data regarding various molds.

The speed change command unit 33 obtains dimensional data about the mold to be used from the mold data storage unit 31, and determines the predicted position Z _O for setting the mold origin of the ram 9 (see FIG. 4).
Set the speed change position Z _V to a position a little closer (for example, 2 mm). Then, this changed position Z _V and the actual position Z are compared, and the actual position Z is changed to the changed position Z _V
When this happens, a speed change command S _V is output to the servo valve control section 27 to make the speed slow.

The position comparison unit 35 obtains dimensional data about the mold used from the mold data storage unit 31, calculates the predicted position Z O of the mold origin setting of the ram 9, and calculates the predicted position Z _O of the mold origin setting of the ram 9, and calculates a position slightly (for example, 0.3 mm) below this position. position to safe position
Set to _ZS . Then, this position Z _S and the actual position Z
When the actual position Z reaches the safe position _ZS , a stop command _Ss is output to the servo valve control section 27 to make an emergency stop of the ram 9.

The pressure comparison unit 37 compares the preset origin setting pressure P _T and the detected pressure Pd of the pressure detector, and when the detected pressure Pd reaches the set pressure P _T , the servo valve control unit 27 At the same time as outputting the ram stop command S _S , the origin setting command S _T is sent to the mold origin setting section 39.
This outputs the following.

The mold origin setting section 39 receives the origin setting command S _T and sets the current ram position Z to the mold origin position Z _T .

Next, a mold origin setting method for the bending machine having the above configuration will be explained with reference to FIGS. 3 and 4.

In FIG. 3, in step 301, condition setting processing is performed. That is, here, the speed change command section 33 reads the dimension data of the mold from the mold data storage section 31, subtracts a predetermined distance ΔZ from the planned mold origin position _ZO shown in FIG. Set the speed change position _ZV . Also, here, the position comparison unit 35 determines a position slightly below the planned mold origin position _ZO , and sets this as the safe position _ZS .

Therefore, a switch (not shown) for setting the mold origin
When turned on, in step 303, the ram 9 starts descending at high speed. At this time, the servo valve 19
In order to operate the ram 9 at high speed, the pressure Pm supplied to the ram 9 is adjusted to a relatively high pressure by a pressure regulating valve 17.

In step 305, the ram 9 moves to the speed change position.
It is determined whether or not Z _V has been reached, and if Z=Z _V , the process moves to step 307.

In step 307, the speed of the ram 9 is slowed down, and at this time, the hydraulic pressure supplied to the servo valve 19 is set to the minimum necessary pressure P _L. The minimum necessary pressure is a pressure that is slightly higher (for example, 30% higher) than the sufficient pressure necessary to set the mold origin.

In step 309, it is determined whether the cylinder pressure P has reached the set pressure P _T for mold setting, and
In step 311, it is determined whether the ram 9 has reached the safe position _ZS or not.

Therefore, in step 309, the cylinder pressure P reaches the set pressure until the ram 9 reaches the safe position _ZS .
By reaching P _T , an appropriate position for setting the mold origin can be detected.

In step 309, the detected pressure P of the ram 9 becomes the set pressure.
If it is determined that P _T has been reached, proceed to step 3.
13, where the current position Z is set to the mold limited position _ZT . The ram 9 is temporarily stopped at this point and then rises towards the upper limit position Zu.

Also, in step 311, if Z = Z _Z without P = P _T , that is, the ram 9 reaches the safe position, it is assumed that the origin setting has failed.
At this point, the descending of the ram 9 is stopped, and after investigating the cause, the safe position Z _S is lowered slightly, for example, and the above operation is repeated again.

In addition, since the supply pressure is limited to the minimum necessary pressure P _L , the mold will not be damaged even if an erroneous operation occurs.

Through the above processing, the mold origin position Z _T is set, and thereafter, a predetermined bending process is performed based on this position Z _T according to the plate thickness and the type of bending.

The bending process is no different from normal operation, so
The explanation will be omitted.

In the embodiment shown above, a folding machine in which a ram 9 equipped with a punch 9 is driven up and down is shown, but this invention is applicable to other folding machines, for example, a folding machine in which a die 5 is driven up and down. Of course, the present invention can also be applied to bending machines.

Note that this invention is not limited to the above-mentioned embodiments, but can be implemented in other embodiments by making appropriate changes.

[Effect of idea]

As can be understood from the above description of the embodiments, in short, the present invention provides a ram 9 equipped with a mold 5b for bending a plate material so as to be movable up and down on the upper or lower side of the frame 3. The above mold 5b
A bending machine comprising a table supporting a mold 5a cooperating with the frame 3 fixed to the lower or upper side of the frame 3, and a cylinder 7 for vertically moving the ram 9; A ram position detection unit 29 that detects the vertical position of the ram 9, a servo valve 19 that controls the drive of the cylinder 7 to control the position and vertical speed of the ram 9, and a servo valve that controls the servo valve 19. A control unit 27;
a pressure detector 21 that detects the pressure of the cylinder 7;
The preset pressure P _T and the detected pressure P _d of the pressure detector 21 are compared, and when both pressures become equal, a ram stop command S _S is outputted to the servo valve control section 27. A pressure comparison section 37 that outputs the origin setting command _ST , and a mold that sets the mold origin position Z _T based on the origin setting command _ST of the pressure comparison section 37 and the detection value of the ram position detection section 29. An origin setting section 39 is provided.

Therefore, according to the present invention, when the detected pressure of the pressure detector 21 becomes equal to the set pressure, the vertical movement of the ram 9 is stopped, and this stopped position is also detected by the position detection section 29, and the mold origin position is set. It is done. Therefore, the upper and lower molds are in a pressurized state, and the frame of the bending machine is in a flexed state, so that the mold origin position can be set more accurately.

[Brief explanation of the drawing]

Fig. 1 is a side view of a bending machine according to an embodiment of this invention, Fig. 2 is a block diagram of the control device, Fig. 3 is an explanatory diagram of the mold origin setting method, and Fig. 4 is an illustration of the mold origin setting method. It is an explanatory diagram showing an effect. 5a, 5b...Mold, 7...Cylinder, 9...
Ram, 11... Encoder, 21... Pressure detector, 23... Control device.

Claims (1)

[Scope of utility model registration request] Ram 9 equipped with a mold 5b for bending plate material
is provided vertically movably on the upper or lower side of the frame 3, and a table supporting the mold 5a that cooperates with the mold 5b is fixed to the lower or upper side of the frame 3, and The bending machine is equipped with a cylinder 7 for vertically moving the ram 9, and a ram position detecting section 29 for detecting the vertical position of the ram 9, and a ram position detecting section 29 for controlling the position and vertical movement speed of the ram 9. A servo valve 19 that controls the drive of the cylinder 7, a servo valve control section 27 that controls the servo valve 19, a pressure detector 21 that detects the pressure of the cylinder 7, a preset pressure P _T and the above. a pressure comparison section 37 that compares the detected pressure P _d of the pressure detector 21 and outputs a ram stop command S _S to the servo valve control section 27 and outputs an origin setting command S _T when both pressures become equal; and a mold origin setting section 39 that sets the mold origin position Z _T based on the origin setting command S _T of the pressure comparison section 37 and the detection value of the ram position detection section 29. Features a bending machine.