JPH0815621B2 - Split mold protector for folding machine - Google Patents

Description

Description: [Industrial application] The present invention relates to a mold protection device for a folding machine.

[Prior Art] A bending machine presses a plate material to be processed of a predetermined length between molds arranged vertically and presses the plate material to be processed to a predetermined bending process.

Conventionally, this type of bending machine has not been provided with an effective mold protection device, and a large pressing force is applied to the mold, which deteriorates the durability of the mold or damages it. Was there.

[Object of the Invention] In view of the above points, an object of the present invention is to provide a mold protection device for a bending machine that can effectively protect a mold.

[Summary of the Invention] In order to achieve the above object, a split mold protection device of a folding machine of the present invention is a split machine in a folding machine in which one of upper and lower molds is positionally controlled with respect to the other mold. A used mold determination unit that determines the total length of a used mold configured by combining molds and a mold type prior to processing, and the total length of the used mold and a divided mold based on the determination result of the used mold determination unit Safety load calculation means for calculating the total safety load of the mold to be used from the safety load per unit of, and a safety pressure setting unit for setting the pressure on the pressurizing side of the cylinder based on the calculation result of the safety load calculation means, When the detected pressure exceeds the set pressure in the comparison result of the pressure comparison unit that compares the detected pressure of the pressure on the pressurizing side of the cylinder detected by the detector with the set pressure, the positioning control is performed. Emergency stop signal to stop An emergency stop unit for outputting is provided.

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

First, briefly explaining the drawings, FIG. 1 and FIG. 2 are a side view and a front view of a folding machine capable of implementing the present invention, and FIG. 3 is a perspective view of a mounting mold (lower mold). Is. Further, FIG. 4 is an explanatory diagram of a hydraulic circuit, FIG. 5 is a block diagram of a control circuit, and FIG. 6 is a flowchart of a processing outline regarding die protection.

As shown in FIGS. 1 and 2, the bending machine has a pair of left and right side frames 1, a lower table 3 is fixed to the lower front of the frame 1, and a pair of left and right cylinders 5 is provided above. Is provided.

A lower mold 7 is mounted above the lower table 3, a ram 9 is mounted on the cylinder 5 so as to be moved up and down in the direction of the lower mold, and a ram 9 is mounted below the ram 9 to face the lower mold 7. Then, the upper mold 11 is attached.

As shown in FIG. 3, the lower mold 7 is a mold having a divided structure,
A so-called loose mold is used, and a mold of a predetermined length is attached according to a plate material to be bent by an automatic mold exchanging device (not shown). The mold 7 has a safety (proof pressure) load Wo that allows safe work with respect to a unit length.

A reinforcing plate 13 is attached to the side frame 1, and the reinforcing plate 13 is provided with a position detector 15 (not shown in FIG. 2) for detecting the up-and-down movement of the ram 9.

An electric control board 17 is mounted on the left frame of the side frame 1 in FIG.

In the bending machine having the above configuration, the lower die 7 and the upper die
By inserting a work material (not shown) between 11 and giving a bending command with a foot petal device (not shown) or the like, the ram 9 is lowered and a predetermined bending operation can be performed.

As shown in FIG. 4, the hydraulic circuit for driving the pair of cylinders 5 has a symmetrical structure corresponding to each cylinder 5.

The servo valve SV for supplying pressure oil to the cylinder 5 is a 4-port 1-stage direct-acting type.

The pressure oil supplied to the servo valve SV is generated by a pump P driven by a motor M, and the pressure oil generated by the pump P is supplied via a line filter ILF. Also, the generated pressure oil is the servo valve
An electromagnetic proportional valve SOLE arranged between the SV and the line filter ILF controls the pressure to a predetermined pressure.

The servo valve SV is connected to the cylinder 5 via oil passages OL1 and OL2. The oil passage OL1 is connected to the cylinder upper chamber, and the oil passage OL2 is connected to the cylinder lower chamber via various control valves.

The oil passage OL2 is provided with a counter balance valve CBV capable of giving a predetermined back pressure when returning the oil discharged from the cylinder 5 to the servo valve SV via the oil passage OL2.

Further, in the oil passage OL2, there is a pilot check valve LV1 capable of returning the oil discharged from the cylinder 5 to the servo valve SV only when the pressure oil in the pilot portion is discharged based on the operation of the solenoid valve SOL1. It is provided.

Further, in parallel with the counter balance valve CBV, the oil passage OL2 returns the drain oil from the cylinder 5 directly to the servo valve only when the pressure oil in the pilot portion is discharged based on the operation of the solenoid valve SOL2. A pilot check valve LV2 that enables the above is provided.

The pressure detector 19 connected to the oil passage OL1 is for detecting the oil pressure in the upper chamber of the cylinder 5, and may be directly connected to the upper chamber of the cylinder 5.

In addition to this, in the hydraulic circuit, pressure switches PS1, PS2,
Check valves PCV, LV3, etc. are provided appropriately.

In the hydraulic circuit configured as described above, when it is desired to raise the ram 9, it is sufficient to supply a predetermined flow rate of oil to the lower chamber of the cylinder 5 via the oil passage OL2. When lowering the ram 9, the solenoid valves SOL1 and SOL2 are operated to open the pilot check valves LV1 and LV2, and then the oil discharged from the lower chamber of the cylinder 5 is transferred from the oil passage OL2 to the servo valve SV. Just return it.

As shown in FIG. 5, the control circuit includes a machining command unit 21.
And a ram positioning control unit 23 that positions the ram 9 at a predetermined position to perform a predetermined bending process.

Further, the control circuit of this example is connected to a mold protection circuit for safely performing the bending process in the positioning control section 23.

This protection circuit sets a safe load calculation unit 27 connected to the used mold determination unit 25, and a safe pressure ps that can be applied to the oil passage OL1 based on the safe load calculated by the calculation unit 27. It has a safety pressure setting unit 29. Further, the safety circuit is configured such that the pressure ps set by the setting unit 29 and the pressure detector 19
It has a pressure comparison unit 33 that compares the pressure pD detected in 1. and outputs an emergency stop command signal to the emergency stop unit 31 when pD ≧ ps.

The used mold determination unit 25 also determines the used mold before starting the bending process. The determination of the mold used is made by the mold type and the mold length L shown in FIG.

The safe load calculation unit 27 inputs the judgment result of the used mold judgment unit 25, and the safe load W ₀ per unit length of the used mold.
Is multiplied by the length L to obtain the total safety load W ₀ · L.

The safety pressure setting unit 29 uses the oil passage according to the following procedure.
It seeks the safety pressure ps that can be applied to OL1.

First, the pressurizing forces W ₁ and W ₂ to be distributed to each cylinder 5 are calculated.

W ₁ + W ₂ = W ₀ · L… W ₁ : W ₂ = L ₂ : L ₁ … However, L ₁ and L ₂ are the respective distances from the center position of the plate material on the folding curve to the position directly below each cylinder 5. Is shown. In this example, since the machining length and the length L of the lower mold are the same, the total safety load was calculated as W ₀ · L, but more generally, it is changed to L and the actual machining length (bending length ) L should be used.

Next, the larger value Wm of the loads W ₁ and W ₂ is selected, the cylinder pressure receiving area is set to AC, and the safety pressure ps is obtained.

ps = Wm / AC ... The larger load Wm among the loads W ₁ is adopted here because the ram 9 is lowered in parallel with the mold 7 in the actual bending process while keeping the predetermined height. Since the positioning control is performed to the position, the influence of the cylinder far from the center position is reduced.

As shown in FIG. 6, the mold protection circuit having the above-described configuration calculates the total safety load W ₀ · L of the mold used in step 601, and the safety pressure that can be applied to the oil passage OL 1 in step 603.
Set ps. Further, the mold protection circuit compares the detected pressure pD with the safety pressure ps in step 605, and when pD ≧ ps,
In step 607, an emergency stop is performed.

As described above, in this example, it is possible to set the safety pressure ps for various dies at which there is no risk of damaging the dies in step 603, and when the actual pressure pD is equal to or higher than this value ps, immediately in step 607 Since the bending process is stopped, the bending process can be performed safely.

In the mold protection circuit shown above, the comparison unit 33 and the emergency stop unit 31 are provided so that the positioning control of the positioning control unit 23 is stopped when pD ≧ ps. However, the safety pressure setting unit 29 shown in FIG. The solenoid proportional valve SOLE shown in (3) may be adjusted to regulate the hydraulic pressure supplied to the servo valve SV.

The present invention is not limited to the embodiments described above, but can be implemented in other modes by making appropriate design changes.

[Effects of the Invention] As described above, according to the present invention, since the safety load can be automatically calculated and the actual pressing force can be regulated according to the safety load, the die can be effectively protected.

[Brief description of drawings]

1 and 2 are a side view and a front view of a folding machine capable of implementing the present invention, FIG. 3 is a perspective view of a mounting die (lower die), and FIG. 4 is an explanation of a hydraulic circuit. FIG. 5 and FIG. 5 are block diagrams of the control circuit, and FIG. 6 is a flowchart of an outline of processing relating to die protection. 25 ... Mold used judgment unit 27 ... Safe load calculation unit 29 ... Safe pressure setting unit 31 ... Emergency stop unit 33 ... Pressure comparison unit

Claims (1)

[Claims] 1. A bending machine for controlling the positioning of one of upper and lower dies with respect to the other die, prior to processing the entire length of a die to be used and a die type constituted by combining divided dies. Safety load calculation means for calculating the total safety load of the used mold based on the used mold determination part for determination, and the total length of the used mold based on the determination result of the used mold determination part and the safety load per unit of the divided molds. A safety pressure setting unit that sets the pressure of the hydraulic pressure source based on the calculation result of the safety load calculation unit, a pressure comparison unit that compares the detected pressure of the hydraulic pressure source detected by a pressure detector with the set pressure, A split mold for a folding machine, comprising: an emergency stop unit that outputs an emergency stop signal for stopping the positioning control when the detected pressure exceeds a set pressure in the comparison result of the pressure comparison unit. Protective device.