JPH0237461Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a clamp claw drive device for a transfer feeder of a press.

[Prior art and its problems]

As shown in Fig. 3, the transfer feeder of the press is provided with a feed bar 51 that faces parallel to the upper surface of the lower press mold 50, and uses a cam or cylinder to perform clamping, unclamping, lift, down, advance, and return operations on this feed bar. 3
A plurality of claws 52 attached to a feed bar 51 give a dimensional motion to the workpieces, and the workpieces are gripped and sequentially transferred to the next process.

As shown in FIGS. 2 to 4, such a clamp claw drive device for a transfer feeder has rods 1A and 1 of a double rod type hydraulic cylinder 1.
Connect the tip of B to the feed bar carrier support frame 5.
3, and the cylinder body 1C to which the feed bar carrier 54 is attached is moved in the clamping direction and in the unclamping direction.
Accumulators 4 and 5 are connected to a clamping chamber A and an unclamping chamber B, which are partitioned by a piston 1D, via pipes 2 and 3, respectively.

The piping 2 of the clamp chamber A has a pump 6, a relief valve 7, a check valve 8, and a cam 9 on the cylinder side.
A piston pump 10 driven by is connected. Here, set pressure of accumulators 4 and 5.
P ₁ , P ₂ , maximum pressure P ₃ due to piston pump 10
Then, P ₁ <P ₂ <P ₃ , and clamping and unclamping are performed by increasing and decreasing the pressure in the clamp chamber A using the piston pump 10.

In such a clamp claw drive device, if an abnormality occurs during workpiece conveyance (the workpiece is clamped by the feed bar), the cam 9 is reversed to perform an unclamping operation and the workpiece is taken out of the press. , it took a long time to recover, and production was stopped for a long time.

Further, depending on the posture of the workpiece, it may not be possible to reverse the workpiece, and if the workpiece is forcibly reversed, there are problems such as deformation of the claws in the workpiece clamp.

This idea was proposed in view of the above-mentioned circumstances, and its purpose is to make it easier to remove workpieces from the machine due to transport abnormalities at any position during workpiece transport under clamped conditions, and to reduce production stoppage time. An object of the present invention is to provide a clamp claw drive device for a transfer feeder that can be shortened.

[Means for solving problems]

As shown in FIG. 1, the transfer feeder clamp pawl driving device according to this invention has a clamping chamber A and an unclamping chamber B separated by a piston of a fluid pressure cylinder that operates the clamp pawls. 4 and 5, and a check valve 8 is interposed in the pipe line 2 between the clamping chamber A and the accumulator 4 connected to the clamping chamber A, which allows only the flow of hydraulic oil into the clamping chamber A. A cam-driven piston pump 10 is connected to the pipe line 2 between the check valve 8 and the clamping chamber A.
In the device for increasing and decreasing the pressure in the clamping chamber A, a return piping 12 returning to the tank 11 is connected to the piping 2 between the clamping chamber A and the check valve 8, and a return piping 12 that returns to the tank 11 is connected to the is a closing mechanism that closes the pipeline and opens on command (pilot operation check valve 13, shot-off valve 14, etc.)
and a relief valve 15 whose set pressure is higher than the set pressure of the accumulator 4 connected to the clamping chamber A. When an abnormality occurs, the closing mechanism is opened to allow the fluid in the clamping chamber A to flow out to the tank 11.
Moreover, unclamping can be performed without causing hydraulic oil to flow out from the accumulator 4 connected to the clamping chamber A.

〔Example〕

This invention will be explained below based on an illustrated embodiment. Note that the same reference numerals are given to parts that are the same as or correspond to the conventional ones.

As shown in FIG. 1, a return pipe 12 returning to the tank 11 is connected to the pipe 2 on the cylinder side from the check valve 8, and a pilot operation check valve 13, a shut-off valve 14, and a relief valve are connected to this return pipe 12 in order from the cylinder side. 15 will be provided.

The pilot operation check valve 13 is configured to open and close using the accumulator 5 as a driving source via a spring-off set electromagnetic two-position switching valve 16.

Furthermore, a check valve 13 and a shut-off valve 14
A supply pipe 17 is connected to the return pipe 12 between the two, and a spring-off set electromagnetic two-position switching valve 18 is arranged so that the supply pipe 17 and the pipe 2 can be selected.

In the above configuration, the check valve 13 and the shut-off valve 14 are normally closed, and the cam 9 and piston pump 10 perform clamping and unclamping.

If an abnormality occurs, turn on the two-position switching valve 16, open the check valve 13, and open the shut-off valve 14. The oil in the clamping chamber A returns to the tank 11, and the accumulator 5 releases the cylinder body 1C. It moves in the unclamping direction, allowing the workpiece to be easily taken out.

Here, in order to prevent the oil in the accumulator 4 from flowing out to the tank 11 via the piping 2 and the return piping 12, the set pressure of the relief valve 15 is set higher than the pressure P ₁ of the accumulator 4. .

After taking out the workpiece, perform the following operations to return it to the normal position.

The two-position switching valve 16 is turned off, the check valve 13 is closed, and the shut-off valve 14 is closed.
After the pump 6 is started, the two-position switching valve 18 is turned on to replenish the clamping chamber A with oil together with the hydraulic oil from the accumulator 4 via the supply pipe 17. The oil in the unclamping chamber B returns to the accumulator 5, the cylinder body 1C moves in the clamping direction, and the return operation is completed at the clamping end.

[Effect of idea]

As mentioned above, according to this invention, a return pipe that returns to the tank is provided in the piping of the clamping chamber, and a closing mechanism such as a check valve and a shut-off valve is installed in this return pipe, so that even though it is cam operated, it can be used even in the clamped state. Since the unclamping operation can be performed at any position during transport of the workpiece, it becomes easy to remove the workpiece from the machine due to a transport abnormality, and production stoppage time can be shortened.

In addition, since the set pressure of the relief valve installed in the return pipe to the tank is set higher than the set pressure of the accumulator in the clamp chamber, even if the clamp chamber is connected to the return pipe, etc., the hydraulic oil does not leak out from the storage unit, saving energy.

Further, even when adjusting the pawls, the clamping operation can be performed independently, so that the pawl adjustment time can be shortened.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a clamp claw drive device for a transfer feeder according to this invention, Fig. 2 is a schematic diagram showing a conventional drive device, Fig. 3 is a side view showing the transfer feeder, and Fig. 4 is a schematic diagram showing a conventional drive device. It is a longitudinal cross-sectional view showing a hydraulic cylinder for claw clamping and unclamping. A...Clamping chamber, B...Unclamping chamber, 1...Double rod type hydraulic cylinder, 1A, 1B
... Rod, 1C ... Cylinder body, 1D ... Piston, 2, 3 ... Piping, 4, 5 ... Accumulator, 6 ... Pump, 7 ... Relief valve, 8 ...
Check valve, 9...cam, 10...piston pump, 11...tank, 12...return piping, 13...
... Pilot operation check valve, 14 ... Shutoff valve, 15 ... Relief valve, 16 ... 2-position switching valve, 17 ... Supply piping, 18 ... 2-position switching valve.

Claims (1)

[Scope of Claim for Utility Model Registration] An accumulator is connected to a clamping chamber and an unclamping chamber, which are separated by a piston of a fluid pressure cylinder that operates a clamp claw, and the clamping chamber is connected to the clamping chamber. A check valve that only allows hydraulic oil to flow into the clamping chamber is installed in the pipeline between the accumulator and a cam-driven piston pump connected to the pipeline between the check valve and the clamping chamber. In the transfer feeder clamp claw drive device that increases or decreases the pressure in the clamp chamber, a return pipe returning to the tank is connected to the pipe line between the clamp chamber and the check valve, and the return pipe is normally connected to the tank. A closing mechanism that closes the pipe line and opens upon command, and a relief valve having a set pressure higher than the set pressure of an accumulator connected to the clamping chamber are provided, and the return pipe is connected to the return pipe via a supply cutoff switching valve. A clamp claw drive device for a transfer feeder, characterized in that a pressure oil supply source is connected to the transfer feeder.