JPH028639Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a safety device when starting a press, and more specifically, when starting the press, operation is first started by pressing multiple start operation switches in sequence. The present invention relates to a safety device for a press configured as described above.

Conventionally, starting a press was generally performed in one motion by pressing both left and right push buttons at the same time or by pressing a foot switch. When starting the machine with one action, the operator sometimes pushes the machine unconsciously, and there is a risk that the machine will start even if a tool or workpiece accidentally touches it.

The present invention was made to eliminate the above-mentioned danger, and embodiments thereof will be described in detail below based on the drawings.

FIG. 1 is a wiring circuit diagram showing a reference example of the safety device according to the present invention, in which the vertical line on the left end side is the live wire 1 of the low-voltage AC single-phase power supply (for example, 100 V) for the control device. The vertical line on the right end side is also the ground line 3. The connection to this inner live wire 1 side is temporarily disconnected each time the mode of press operation is changed, which will be described later.

For convenience of explaining the circuit diagram, the horizontal lines connecting the live wire 1 and the ground wire 3 in FIG. 1 are designated as 51, 53, 55,
Named lines 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, and 77.

First, the 51st line and the 53rd line constitute a self-holding circuit that remembers that the press start switch, which will be described later, has been turned ON and holds itself.The 51st line has a relay CR1. The coil section and its normally open self-holding contact CR1 are installed in series, and the No. 53 line has a relay CR3.
Normally closed contact CR3 of relay CR2 and normally open contact CR of relay CR2
2, the normally closed contact CR4 of relay CR4, and the relay
The normally open contact CR21 of CR21 is connected in series, and at the right end thereof, it is connected to the 51st line between the relay CR1 of the 51st line and its normally open contact CR1.

On line 55, the normally closed contact PB1L for the left hand of a two-handed push button switch as a switch for starting the press, the normally closed contact PB1R for the right hand, and the coil of relay CR2 are connected in series. A contact in which the normally closed contact of No. 55 was replaced with a normally open contact.
PB1L, PB1R, and the coil of relay CR3 are connected in series. Line 59 is equipped with a select switch SS1, which allows you to select either a two-handed push button or a foot switch.

Line No. 61 is equipped with a normally closed contact FSW of a foot switch as a separate switch for starting the press, and is connected to the live wire 1 side of relay CR2 of line No. 55 on the right side.

Line 63 has only the normally open contact FSW of the foot switch mentioned above, and is connected to the live wire 1 side of relay CR3 of line 57 on the right side.

The 65th line and the 67th line are the switches PB1L, PB1R or PB1R for starting the press when the self-holding circuit section 51 is in the self-holding state.
This constitutes the solenoid energizing circuit section that energizes the starting solenoid when the FSW is turned on again.
Normally open contact CR3 of CR3, normally closed contact CR2 of relay CR2, normally open contact CR1 of relay CR1,
Coil CR4 of relay CR4 is connected in series. There is also a select switch on line 67.
Contact SS2 for continuous operation and one stroke operation of SS2 and normally open contact CR4 of relay CR4 are connected in series, and on the right side, normally closed contact CR2 of relay CR2 of line 65 and normally open contact of relay CR1. A starting solenoid connected to line 65 between CR1 and closest to ground line 3, in parallel with the above-mentioned relay CR4, which operates the air valve that switches the clutch brake between clutch action and brake action. A solenoid coil SOL1 is provided.

When solenoid coil SOL1 is energized,
The eccentric shaft of the press is connected to the flywheel by the action of the clutch and is driven to rotate, and the slide of the press moves up and down, and the solenoid coil
When SOL1 is demagnetized, a brake action is applied to stop the rotation of the eccentric shaft, and at the same time, the vertical movement of the slide is also stopped.

On line 69, a select switch SS2 extends from the control power supply live wire 1 described above, and this select switch is used to select one of the four operating modes of the press: continuous operation, 1-stroke operation, safe 1-stroke operation, and inching operation. It is a switch to select either one, but in this diagram, only continuous operation and one-stroke operation are listed together as one contact on line 67, and the wiring after the contact is omitted for safe one-stroke operation and dimension operation. It has been done.

Line 71 has normally closed contact CR4 of relay CR4.
, normally closed contact CR2 of relay CR2, and relay CR2
The normally open contact CR3 of No. 3 and the coil of relay CR20 are connected in series, and the normally open contact CR20 of relay CR20 is provided for self-holding on the No. 73 line, and both ends thereof are connected to the No. 71 line. relay
Normally closed contact CR2 live side of CR2 and relay CR3
It is connected to the ground wire side of the normally open contact CR3.

Line 75 is connected to the ground side of the normally closed contact of relay CR4, and is connected to the normally open contact CR20 of CR20.
, normally open contact CR2 of relay CR2, and relay CR2
The normally closed contact CR3 of No. 3 and the coil of relay CR21 are connected in series, and the relay No. 77 is connected to the coil of relay CR21.
A normally open contact CR21 of CR21 is provided for the purpose of self-holding of relay CR21, and its both ends are
Between normally open contact CR20 of CR20 and normally open contact CR2 of relay CR2, and normally closed contact CR3 of relay CR3
It is connected to line 75 between the coil of relay CR21 and the coil of relay CR21.

Next, the operation of the above configuration will be explained. In addition, select switches SS1 and SS2 are the first
Assume that the connections are as shown in the figure.

First, when the operator presses two-handed push button switches PB1L and PB1R as switches for starting the press, 55
Relay CR2 on line No. 57 is demagnetized and relay CR3 on line No. 57 is energized, so contacts CR2 and CR3 on line No. 71 are both turned on, and relay CR
20 is energized and enters a self-holding state. Next, when the two-handed pushbutton switches PB1L and PB1R are released, relay CR3 on the 57th line is deenergized and relay CR2 on the 55th line is energized again. Therefore, contacts CR2 and CR3 of line 75 are both turned on, and relay CR21 is energized and enters a self-holding state.

As mentioned above, when relay CR21 is energized,
Each contact on the 53rd line is turned on, and the relay CR1 on the 51st line is energized and becomes a self-holding state.
It remembers that the switch for starting the press has been turned on once.

Next, the two-handed push button switches PB1L and PB1R
When is pressed again, relay CR2 on the 55th line is deenergized again, and relay CR3 on the 57th line is energized again. Therefore, each contact CR3, CR2, CR1 of line 65 is turned on, and relay CR4 is turned on.
is excited, and this relay CR4 enters a self-holding state. At the same time, solenoid SOL1 of line 67
is energized and the press is activated. Furthermore, relay contact CR4 on line 71 is turned off, and the relay
The self-holding of CR20 and CR21 is released and they return to their original state.

When the select switch SS1 is connected to the 61st line side, the press is activated in the same way as described above by stepping on the foot switch FSW twice.

2, 3 and 4 show embodiments of the present invention.

The footswitch in this embodiment includes a first footswitch FSW1 under a cover 5 that protects the switch from falling objects, and a second footswitch near the exposed rear end (left end in FIGS. 2 and 3).
FSW 2 is provided, and both are spaced apart by a size that prevents the shoes 7 from being stepped on at the same time by the toe and heel of the shoe 7 shown by the two-dot chain line.

The circuit configuration and operation will be explained from Fig. 4.
Connection lines including a large number of switches, relays, and relay contacts are provided between the control power supply live line 11 side and the ground line 13 side.
They named lines 81, 83, 85, 87, and 89.

The 79th line and the 81st line constitute a self-holding circuit section, and the 79th line has the above-mentioned first foot switch FSW1, the normally closed contact CR1 of the relay CR1, and the coil of the timer relay TR1 connected in series. It is connected to. On line 81, a normally open contact TR1 of timer relay TR1 is provided for self-maintenance. This timer relay TR1
has a function of closing the normally open contact TR1 for a predetermined period of time (for example, 3 seconds) and then opening it.

Lines 83, 85 and 87 constitute the solenoid energizing circuit.
The second foot switch mentioned above is installed on the second line.
FSW2, normally open contact TR1 of the timer relay,
The coil of relay CR1 is connected in series.
In addition, the normally open contact CR1 of relay CR1 is on the 85th line.
and the coil of relay CR2 are connected in series,
A solenoid coil SOL1 is provided in parallel with relay CR2.

On line 87, there is a terminal for continuous operation of select switch SS1 on line 89, and relay CR2.
It is connected to relay CR2 via the self-holding normally open contact CR2, and the select switch of line 89
The other terminals in SS1 are for inching and one safety stroke, and their details are omitted.

SOL1 has the function of operating the clutch that connects the eccentric shaft of the press to the flywheel and switching the air valve to the air cylinder that operates the brake, and while solenoid SOL1 is energized, the eccentric shaft of the press is The core shaft is driven by the flywheel under the action of the clutch and rotates to move the slide, and during demagnetization the slide is stopped under the action of the brake.

To operate, first press the first switch FSW1, which is protected by the foot switch cover 5, with the toe of your shoe to self-hold the timer relay TR1, and then press the second switch FSW2 with your heel within 3 seconds, for example, to continuously activate the switch. When the operation starts and press work continues, the first switch FSW1 is turned on.
Turn on the second switch FSW2 within 3 seconds, for example.
It will not start unless you turn it on.

As is clear from Figure 4, the second switch
Even if FSW2 is turned on first, relay CR1 is not energized, and even if first switch FSW1 is turned on afterwards, solenoid coil SOL1 is not energized.

As can be understood from the description of the embodiments described above, according to the present invention, the press cannot be started unless the switches for starting the press are sequentially operated.
This makes it possible to prevent activation due to erroneous operation, making it extremely safe.

It should be noted that the present invention can be implemented in other forms than the above-described embodiments by making appropriate design changes.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram as a reference example of the present invention, Fig. 2 is a plan view of the foot switch, Fig. 3 is an elevational view of the same, and Fig. 4 shows the foot switch of Figs. 2 and 3. It is a circuit diagram showing an example used. 1... Control power supply live wire, 3... Control power supply ground wire,
PB1L...Push button with both hands for left hand, PB1R...Push button with both hands for right hand, SOL1...Solenoid coil, FSW
1...First foot switch, FSW2...Second foot switch.

Claims (1)

[Scope of utility model registration request] The first foot switch FSW1 for starting the press is
Self-holding circuit section 7 that remembers that it has been turned on
9, and a second foot switch whose ON operation is effective when the self-holding circuit section 79 is in the self-holding state.
FSW2 and the second foot switch FSW2 are turned ON, the self-holding state is activated, and the starting solenoid is turned on.
A press starting safety device comprising: energizing circuit parts 85 and 87 that energize SOL1.