JPS6411400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a press device, and more particularly to a double drop prevention device that prevents a slide from falling twice.

There are various types of press operation: slow speed, inching, safe single stroke, and continuous, but safe single stroke operation requires the slide to stop reliably at top dead center, and for this reason, a slide double-drop prevention device is important. It has become a requirement.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel slide double fall prevention device that operates reliably and is easy to install.

The present invention will be explained below based on the illustrated embodiments. In this embodiment, two protrusions 2 and 3 are provided on a cam 1 that rotates in synchronization with a crankshaft (not shown), so that a proximity switch 4 is turned on twice during one revolution of the crankshaft. . The protrusions 2 and 3 are formed so that the protrusion 2 is turned off at the beginning of rotation, and the protrusion 3 is turned off at the end of rotation. As mentioned above, this embodiment uses the cam 1 that synchronizes with the crankshaft, but a protrusion is provided on the slide that moves up and down as the crankshaft rotates to turn the proximity switch on and off. Good too.

FIG. 2 is a circuit diagram of an embodiment of the present invention, and FIG. 3 is a circuit diagram of a general press operation. Therefore, detailed description of FIG. 3 will be omitted except for those directly related to the present invention. Lines 5 and 6 are connected to power supplies RC and TC. Buttons 7 to 11 to select the type of press operation between lines 5 and 6 and relays 12 to 1
6 is connected. Relay 1 for safe one-stroke operation
It is 5. Note that relay 12 is in slow speed, relay 13 is off, relay 14 is in inching, and relay 16 is in continuous operation. Additionally, there are two push buttons 1 for emergency stop between lines 5 and 6.
7, 17, a switch 18 for detecting air pressure, and a contact 19a of a monitor lock relay 19, which will be described later.
A series circuit of the operating relay 20 is connected, and in parallel with the operating relay 20, another contact 19b of the monitor lock relay 19 and a solenoid valve 21 for preventing double drop are connected.
series circuit) are connected. This solenoid valve 21
When turned off, the crankshaft forcibly stops rotating and the slide (not shown) stops falling.

A line 22 is connected to the connection point between the switch 18 and the contact 19a. Between these lines 22 and 6, there is a contact 15a of the relay 15 and a contact 23a of a monitor test relay 23 (FIG. 3), which will be described later.
, a series circuit of the proximity switch 4 and the monitor monitoring relay 24) are connected. Connected in parallel to the proximity switch 4 and the monitor monitoring relay 24 are a contact 24a of the monitor monitoring relay 24 and a circuit of an auxiliary relay 25, and a contact 26a of a monitor set relay 26 and a circuit of a check relay 27, which will be described later. A self-holding contact 25a is connected in parallel to the contact 24a, and a series circuit of a contact 25b of the auxiliary relay 25 and a contact 24b of the monitor monitoring relay 24 and a self-holding contact 27 are connected to the contact 26a in parallel.
a is connected.

Also, check relay 27 is contact 1 of relay 15.
5b to line 22. 28
is a push button having a lamp inside and a contact 28a, and a contact 27b of the check relay 27,
It is connected between lines 22 and 6 via contact 19c of monitor lock relay 19. The monitor set relay 26 is connected to the monitor set relay 2 through the contact 28a and the contact 29a of the press clutch 29 (FIG. 3).
It is connected between the lines 22 and 6 via the contact 26b of 6. Furthermore, the contact 26a is connected in parallel to the circuit of the contact 24c of the monitor monitoring relay 24, the self-holding contact 19d, and the contact 2 of the check relay 27.
7c and the circuit of contact 19d are connected for self-maintenance. In the figure, contacts 15b, 23a,
24b, 24c, 27c are break contacts,
Others are makeup contacts.

A test button 29a is connected in parallel to the contact 19a, and a series circuit consisting of a contact 20a of the press operation relay 20, a contact 30a of the restart prevention relay 30, and a lamp 31 is connected between the lines 22 and 6.

Since FIG. 3 is the same as the general press operation circuit except for the test button 29b and the monitor test 23 which are interlocked with the test button 29a, only the names of the respective members are listed. The contacts of the relays are shown with the same numbers appended with alphanumeric characters. 32, 32
29 and 33 are press clutch relays, 34 is a press clutch auxiliary relay, 35 is a clutch brake, and 30 is a restart prevention relay.

The operation of the above embodiment will be explained below.

If it is not a safe one-stroke, there is no need to prevent a double fall, and in this embodiment, the relay 15 is first activated by the push button 10. Therefore, contact 15a is on and contact 15b is off. When the pushbutton 28 is pressed to turn on the contact 28a prior to operation,
The monitor set relay 26 operates and the contact 26
a, 26b are turned on. When the contact 26a is turned on, the check relay 27 is operated, and when the contact 26b is turned on, the monitor lock relay 19 is turned on. The two relays are self-maintained by contact 27a and contact 19d, respectively. Contacts 19a, 1 due to operation of monitor lock relay 19
9b turns on the solenoid valve 21, and at the same time, the press operation relay 20 operates.

Since restart prevention relay 30 is on, contact 3
0a is on, and when the contact 20a is turned on, the lamp 31 lights up to notify that the vehicle is ready for operation.

Since contact 20b (Fig. 3) is also turned on,
When the operator turns on the operation buttons 32, 32, the press clutch relays 29, 33 operate, and at the same time as the crankshaft begins to rotate, the monitor test relay 23 operates. This operation of relay 23 turns off contact 23a, and check relay 27 turns off. Therefore, contact 27c is turned on, and monitor lock relay 19 is self-held even through this circuit. If the operation buttons 32, 32 are held down, the contact 23a remains off, so
Even if the protrusion 2 of the cam 1 turns on the proximity switch 4, the monitor monitoring relay 24 will not turn on. The crankshaft continues to rotate, and when it rotates by a certain angle or more, it continues to rotate even if the operation buttons 32, 32 are released, performs press work, and continues to rotate until the top dead center. At this time, the protrusion 3 turns on the proximity switch 4. This time, the operation buttons 32, 32 are off,
Since the monitor test relay 23 is off, the contact 23a is on, and the monitor monitoring relay 24 is activated. The auxiliary relay 25 is operated by the contact 24a and is self-maintained.

Contact 24c is turned off, but since contact 27c is turned on as described above, monitor lock relay 19 remains turned on. When the protrusion 3 passes and the proximity switch 4 turns off, the monitor monitoring relay 2
4 is turned off, and the contact 24c is turned on again.
At the same time, contact 24b is also turned on and check relay 2
7 operates and contact 27c turns off, but contact 2
4c is turned on first, the self-holding of the monitor lock relay 19 continues as it is, and therefore the solenoid valve 21 also remains as it is.

If the crankshaft then stops at the top dead center, it will remain in this state, and the same operation will be maintained again by pressing the operation buttons 32, 32.

However, if the crankshaft does not stop at the top dead center, but slips and continues to rotate, the protrusion 2 of the cam 1 turns on the proximity switch 4, and the monitor relay 24 is operated again. At this time, the check relay 27 is in operation and the contact 27c is off, so the self-holding of the monitor lock 19 is released by turning off the contact 24c, and the contacts 19a and 19b are turned off, so the solenoid valve 21 is turned off. It turns off and stops the rotation of the crankshaft. At the same time, the press operation relay 20 is also turned off and the contact point 20b is turned off, so that even if the operation buttons 32, 32 are pressed, the press device no longer operates, thus preventing the slide from falling twice.

The test buttons 29a and 29b are for testing the double fall prevention device, turning on 29a and turning on 29b.
is turned off, the button 29 is pressed to operate the monitor set relay 26 and the monitor lock relay 19, and the solenoid valve 21 is turned on.
When 32 is pressed, the crankshaft rotates, the proximal switch 4 is turned on by the protrusion 2 of the cam 1, the monitor monitoring relay 24 is operated, and the contact 24c is turned off, causing the monitor lock relay 19 to self-hold. The solenoid valve 21 is turned off to stop the rotation of the crankshaft. Therefore, it can be known that the double-drop prevention device operates reliably.

During the above test, the test button 29b is used to prevent the monitor test relay 23 from working, so the check relay 27 remains on and the first protrusion 2 approaches the proximity switch 4. Therefore, it will be easily understood that the above operations are performed.

As described above, according to the present invention, the solenoid valve is turned on by the monitor lock relay prior to operation, and when the crankshaft makes one rotation or more, the self-holding of this relay is released, so that the crankshaft Since the rotation is stopped, it is possible to reliably prevent a double drop.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the relationship between a cam rotating in synchronization with a crankshaft and a proximity switch according to an embodiment of the present invention, and FIGS. 2 and 3 are electrical circuit diagrams of the present invention. 1...Cam, 2, 3...Protrusion piece, 4...Proximity switch, 15...Relay, 19...Monitor lock relay, 21...Solenoid valve, 32...Run button.

Claims (1)

[Claims] 1. A monitor lock relay that is turned on in advance and self-held; a solenoid valve that is maintained in the on state by the contacts of the monitor lock relay and stops the rotation of the crankshaft when turned off; A proximity switch that is turned on twice at the beginning and end of rotation, a run button that is turned on and off to operate the press, and a drive button that is synchronized with the on and off of the proximity switch when the run button is off. a monitor monitoring relay that operates when the monitor monitoring relay operates; a check relay that operates and self-holds when the monitor monitoring relay is activated; and a check relay that is released from self-holding when the operation button is turned on; and a control circuit for releasing the self-holding of said monitor lock relay when both are in operation.
Drop prevention device.