JPS6351771B2 - - Google Patents

Description

Detailed Description of the Invention The present invention moves a set of two feed bars having a plurality of gripping claws on opposing sides three-dimensionally by sequentially operating a plurality of hydraulic cylinders installed at both ends of the feed bar. This relates to a hydraulic operation circuit for hydraulic transfer feed devices.It reduces the inertia during movement of moving parts such as feed bars to enable smooth forward movement, and also accumulates the movement inertia of the moving parts to control each hydraulic pressure. It is possible to downsize and reduce the capacity of the hydraulic pump that applies return operating force to the cylinder and the electric motor that drives it, as well as reduce the power cost required for the electric motor, as well as the lack of hydraulic oil in the forward chamber side pipe of each hydraulic cylinder. The present invention aims to provide a hydraulic operation circuit for a hydraulic transfer feed device that can provide a replenishment device at low cost.

The embodiment will be explained below with reference to the drawings. In Figs. 1 to 4, 1 is an advance cylinder that advances or returns the feed bars 2, 2, and 3R, 3L is a lift that moves the feed bars 2, 2 up and down. Cylinders 4R and 4L are clamp cylinders that operate the feed bars 2 and 2 to clamp or release the material using gripping claws 5, 5, . . . attached to the feed bars 2, 2.

And, the reciprocating chambers 1', 3R',
3L', 4R', 4L' and forward chambers 1'', 3R'', 3L'', 4
R'' and 4L'' are connected by a closed pipe 7 which has a check valve 6 that can supply oil only to the forward movement chamber, and is connected to the return movement chambers 1', 3R', 3L', 4R', 4L'. A pressure reducing valve 20 and an accumulator 8 for absorbing and accumulating hydraulic fluid in the reciprocating chamber are connected in this order from the check valve 6 side to the conduit between the check valve 6 and the reciprocating chamber 1'',
Hydraulic pumps 9, 10, 11, 1 are installed in the pipes between 3R'', 3L'', 4R'', 4L'' and the check valve 6, respectively.
2 and 13 are interposed.

Reference numeral 14 denotes a pressure switch that is activated when the pressure in the accumulator pipe exceeds a set value.The ON signal from this switch activates the solenoid valve 15, and the pressure oil being sent out from the hydraulic pump 16 is controlled. Although the hydraulic pump drive motor 17 is unloaded, the hydraulic pump driving electric motor 17 may be stopped by the ON signal of the pressure switch 14.

18 is a check valve, and 19 is a relief valve connected to a pipe line between the hydraulic pump 16 and the check valve 18.

21 is the forward movement chamber 1″, 3R″, 3L″ of each cylinder,
4R″, 4L″ and hydraulic pump 9, 10, 11, 12,
This is a relief valve connected to the pipe line between 13 and 13.

22, 23, 24, 25, and 26 are cams mounted on the camshaft that operate each hydraulic pump individually in response to each feed bar operation (advance and return, clamp and unclamp, lift and down operations). The stroke points are directly connected and shifted by a desired angle.

Since the hydraulic operation circuit of the present invention is constructed as described above, when operating the hydraulic transfer feed device, first, the electric motor 17 is started to operate the hydraulic pump 16, and the hydraulic pressure is accumulated in the accumulator 8.

When the required hydraulic pressure is accumulated in the accumulator 8, the pressure switch 14 is activated, and the solenoid valve 15 is switched by the ON signal, and the pressure oil being sent out from the hydraulic pump 16 is unloaded.

In this state, the hydraulic pressure in the accumulator 8 is
Acting on L′, forward movement chambers 1″, 3R″, 3L″, 4R″, 4
The hydraulic oil for L″ is hydraulic pumps 9, 10, 11, 12,
The piston rod ends 9', 10', 11', 12', 13' are pushed back into the cams 22,
It is pressed against the curved peripheral surfaces of 23, 24, 25, and 26.

After the above preparation operations, the cams 22, 23, 24, 25, 26 are directly connected and shifted by a desired angle.
When the is rotated by the drive device 27 that rotates in synchronization with the press drive source, the hydraulic pump 9 first starts operating along the curved circumferential surface of the cam 22, and the hydraulic oil in the hydraulic pump 9 becomes high-pressure oil and flows into the advance cylinder. The advance cylinder 1 accelerates and decelerates at a speed corresponding to the shape of the cam 22 from the time when the pressure inside the forward movement chamber 1'' overcomes the pressure inside the backward movement chamber 1'. is applied continuously to perform a stroke operation and advance the feed bars 2, 2.

At this time, the pressure oil in the reciprocating chamber 1' is fed to the feed bar 2,
It is returned to the accumulator 8 and accumulated while preventing overstroke due to inertia of the second moving part.

After the cam 22 further rotates and maintains the stroke state for a predetermined period of time, the cam radius moves to a region where it decreases. This time, the pressure oil accumulated in the accumulator 8 acts on the reciprocating chamber 1', causing the reciprocating chamber to The hydraulic oil returns to the hydraulic pump 9, and the feed bars 2, 2 are moved to the cam 22.
Acceleration and deceleration are applied successively at a speed corresponding to the shape of , and a return operation is performed. In this way, the hydraulic oil only flows between the double action chamber 1' of the advance cylinder 1 and the accumulator 8, and no oil consumption occurs.

Next, regarding the lift cylinders 3R, 3L and the clamp cylinders 4R, 4L, cams 23, 24, 2 whose operation timings are sequentially delayed along with the cam 22.
Hydraulic pumps 10, 11, 1 by rotation of 5, 26
2 and 13 start strokes in sequence, and correspondingly, the lift cylinders 3R and 3L kumpf cylinders 4
R and 4L operate in the same manner as in the case of the advance cylinder 1, and raise and lower the feed bars 2 and 2 and feed bar mounting claws 5 and
5 Clamping and unclamping of the material by...
Advance and return operations of feed bars 2 and 2 are applied in a superimposed manner.

Therefore, the feed bars 2, 2 are operated three-dimensionally in the order of clamp → lift → advance → down → unclamp → return, and the material is sequentially fed by the gripping claws.

In addition, when each cylinder does not perform the prescribed stroke operation due to trouble on the moving part side, the forward movement chambers 1'', 3R'', 3L''4R'', 4L'' of each cylinder and the hydraulic pumps 9, 10, 11, 12 , 13 will be abnormally high pressure, but this will be released by the relief valve 21, and the insufficient oil due to troubleshooting will be removed from the pressure reducing valve 20 from the accumulator circuit during the return process of the hydraulic pump.
is replenished via.

As described above, the present invention includes an accumulator that is pipe-connected to the reciprocating chamber of each hydraulic cylinder, and the reciprocating chamber and the reciprocating chamber of these hydraulic cylinders are
Since it is connected by a series of closed pipes that include a check valve and a pressure reducing valve that can supply oil only to the forward chamber, there is no consumption of hydraulic fluid in the backward chamber during normal feeder operation, so the hydraulic pump can be turned off. can be loaded or stopped,
Therefore, the power cost required for the electric motor to drive the hydraulic pump can be reduced, and the hydraulic pump and the electric motor that drives it can be made smaller and smaller in capacity, reducing costs. It absorbs the inertia energy of the moving parts and enables smooth material feed operation without shock or vibration, and
The generated energy can be used effectively by accumulating and regenerating inertial energy, and in addition, in the present invention, when there is a shortage of hydraulic oil in the forwarding chamber side pipe of each hydraulic cylinder, a part of the accumulator pressure oil is supplied through the pressure reducing valve. Therefore, there are many advantages, such as eliminating the need for a dedicated low-pressure hydraulic oil replenishing device and reducing the cost of the device.

[Brief explanation of the drawing]

Figure 1 is a plan sectional view of a forging press with a hydraulic transfer feed device, Figure 2 is a side sectional view taken along the line in Figure 1, Figure 3 is an explanatory diagram showing the hydraulic pump and its drive system, and Figure 4. FIG. 2 is a hydraulic circuit diagram for a hydraulic transfer feed device according to the present invention. 1... Advance cylinder, 2, 2... Feed bar, 3R, 3L... Lift cylinder, 4R, 4L...
Clamp cylinder, 5, 5... Gripping claw, 6... Check valve, 7... Closed pipe line, 8... Accumulator, 9...
Hydraulic pump, 10... Hydraulic pump, 11... Hydraulic pump, 12... Hydraulic pump, 13... Hydraulic pump, 20
...Pressure reducing valve, 1'...Returning chamber, 3R'...Returning chamber, 3L'...
Reciprocating chamber, 4R'...Return chamber, 4L'...Return chamber, 1''...Return chamber, 3R''...Return chamber, 3L''...Return chamber, 4R''...Return chamber, 4L''...Return chamber Motion room, 22, 23, 24, 25,
26...Rotating cam.

Claims (1)

[Claims] 1 A hydraulic cylinder that moves the feed bar reciprocally in its longitudinal direction, a hydraulic cylinder that moves the feed bar up and down, and a hydraulic cylinder that moves both feed bars toward and away from each other are attached to both ends of a pair of feed bars each having a plurality of gripping claws on opposing sides. The forward movement chambers 1″, 3R″, 3 of each hydraulic cylinder are
L″, 4R″, and 4L″ are equipped with hydraulic pumps that are directly connected to piping and individually operated by rotary cams corresponding to each movement of the feed bar,
The reciprocating chambers 1', 3R', 3L', 4R', and 4L' are equipped with an accumulator that supplies, maintains and accumulates reciprocating oil at a predetermined pressure. The cams are connected by a series of closed pipes that include a check valve and a pressure reducing valve that allow oil to be supplied only to the forward chamber.
A hydraulic operation circuit for a hydraulic transfer feed device, characterized in that it is driven in series in the order of unclamping and return.