JPH0338035B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screw press, and particularly to a screw press of the type in which a slide is lowered and raised by a lead screw.

In a screw press like the one mentioned above, the main screw is raised and lowered along with the slide using a hydraulically operated cylinder.
There are well-known screw presses in which the main screw is screwed into a female screw fixed to the frame and rotates, rotating a flywheel that is integrated with the main screw. has problems in terms of efficiency.

The object of the present invention is to solve the problems of the conventional screw press as described above and to obtain an efficient screw press.

That is, in this invention, the lower end of the main screw is rotatably connected to a slide that is attached to a frame so as to be able to move up and down, the main screw is screwed into a main female screw fixed to the frame, and the slide is moved by rotation of this main screw. A flywheel is fixed to the upper end extension of the main screw, and an auxiliary screw is integrally provided above the flywheel, concentric with the main screw, having a smaller diameter than the main screw, and having the same lead as the main screw. In the screw press, the upper end of a hydraulic cylinder controlled by a hydraulic circuit is connected to the lower end of the elevating frame, which is attached to the upper part of the frame so that it can be raised and lowered.
A screw press is provided in which a piston rod protruding from the lower end of the hydraulic cylinder is connected to a bracket provided on the slide, and the auxiliary screw is screwed into an auxiliary female screw provided on the elevating frame.

The details of the screw press of the present invention will be explained below based on an embodiment shown in the accompanying drawings.

In the figure, reference numeral 1 denotes a frame, at the bottom of which is provided a table 2 for attaching a lower die, and above the frame is a slide 3 for attaching an upper die. This slide 3 moves up and down along guides on both sides of the frame 1, and on both sides of a bracket 3' fixed to the top of this slide 3, there are lower ends of piston rods 5 protruding from the lower ends of a pair of left and right hydraulic cylinders 4. is a spherical bearing 6
connected by.

7 is a main screw whose lower end is connected to the slide 3 by a bearing 8 such as a tapered roller bearing.

The main screw 7 extends upward to fix the flywheel 9 to the extended portion thereof, and an auxiliary screw 10 coaxial with the main screw 7 is integrally provided at the upper end.

A main female screw 11, into which the main screw 7 is screwed, is fixed between the upper portions of the frame 1. The center of the lower end of an elevating frame 13 for auxiliary screws is fitted into the upper part of the cylindrical body 12 outside the female screw 11 so as to be able to move up and down. An auxiliary female screw 15, into which the auxiliary screw 10 is screwed, is fixed to the center of the upper end of the elevating frame 13.

16 is an oil tank, 17 is a hydraulic pump driven by a motor 18, and an oil feed pipe 1 communicating with its discharge port.
9 is provided with a relief valve 20, a check valve 21, and an accumulator 22. Further, this oil feed pipe 19 branches into two through an electromagnetic proportional switching valve 23 and communicates with directional switching valves 24 and 25, and these valves 24 and 25 communicate with oil feed pipes 26 and 27, respectively. 26 and 27 communicate with the upper and lower parts of the hydraulic cylinder 4.

Further, the oil feed pipes 26 and 27 are provided with directional switching valves 28 and 29, respectively, and the outlets of these switching valves are communicated with the oil tank 16 through an oil drain pipe 30.

Further, each oil pipe 26, 27 has a check valve 31, 32, a check valve 33, 34, and a relief valve 35, respectively.
Connect as shown.

The main screw 7 and the auxiliary screw 10 are multi-head screws with large leads, and both screws have the same lead.

The screw press of the present invention has the above-mentioned configuration, and its operation will be explained below.

In the state shown in the figure, when the switching valves 25 and 28 are opened and the switching valves 24 and 29 are closed, the pressure oil that has passed from the hydraulic pump 17 through the check valve 21 and the electromagnetic proportional switching valve 23 is sent via the switching valve 25. It flows into the upper part of each hydraulic cylinder 4 from the oil pipe 27 .

On the other hand, the oil in the lower part of each cylinder 4 passes through the oil supply pipe 26 and is discharged to the oil tank 16 via the switching valve 28, so that the piston rod 5 is lowered and the slide 3 is lowered.

Therefore, the main screw 7 descends together with the slide 3 while rotating along the main female screw 11, and the flywheel 9 integrated therewith rotates.

When the piston rod 5 descends as described above, the reaction force acts on the hydraulic cylinder 4, generating an upward axial force in the hydraulic cylinder 4, which is transmitted to the elevating frame 13 for the auxiliary screw, and descends together with the main screw 7. Since the auxiliary female screw 15 rises relative to the auxiliary screw 10 and applies rotational force to the auxiliary screw 10, sufficient energy is stored in the flywheel 9.

When the slide 3 reaches the lower limit in this manner, pressing is performed by the lower mold on the table 2 and the upper mold on the slide 3. After the press is finished, the switching valves 25 and 28 are closed and the switching valves 24 and 29 are opened to apply hydraulic pressure to the lower part of the cylinder 4, and the oil in the upper part of the cylinder 4 is transferred to the piston rod 5.
The slide 3 is pulled inward, and the slide 3 rises, and the main screw 7
And the auxiliary screw 10 is reversed together with the flywheel 9.

As mentioned above, when the slide 3 rises, reaches the upper limit, and stops, the sudden increase in the oil pressure in the oil feed pipe 26 is recovered by the accumulator 22, and the hydraulic cylinder 4 acts as a brake.

The screw press of the present invention performs the above-mentioned function, and since the main screw and the auxiliary screw have the same lead, and the auxiliary screw has a smaller diameter, the auxiliary screw has a larger lead angle than the main screw. Therefore, less energy is dissipated during the lowering of the slide than in conventional friction screw presses.

In addition, when the piston rod descends, the reaction force acts on the hydraulic cylinder, creating an upward axial force on the hydraulic cylinder, which is transmitted to the auxiliary frame for the auxiliary screw, which assists the auxiliary screw that descends with the main screw. Since the female screw rises and applies rotational force to the auxiliary screw, sufficient energy is stored in the flywheel.

Furthermore, the sudden increase in the hydraulic pressure in the hydraulic circuit when the slide stops rising is recovered by the accumulator, and the hydraulic cylinder is configured to act as a hydraulic brake, so excess energy is recovered and the power is increased. This has the effect of reducing losses.

[Brief explanation of the drawing]

The drawing is a partially vertical front view of an embodiment of the screw press of the present invention. 1...Frame, 3...Slide, 4...Hydraulic cylinder, 5...Piston rod, 7...Main screw, 9
...Flywheel, 10...Auxiliary screw, 11...
Main female screw, 13... Lifting frame, 15... Auxiliary female screw, 22... Accumulator.

Claims (1)

[Claims] 1. The lower end of the main screw is rotatably connected to a slide that is attached to the frame so that it can be raised and lowered, and the main screw is screwed into the main female screw fixed to the frame, so that the main screw slides by rotation of the main screw. A flywheel is fixed to the upper end extension of the main screw, and an auxiliary screw is integrated above the flywheel, concentric with the main screw, having a smaller diameter than the main screw, and having the same lead as the main screw. In the screw press set up,
The upper end of a hydraulic cylinder controlled by a hydraulic circuit is connected to the lower end of the elevating frame, which is attached to the upper part of the frame so that it can be raised and lowered, and the piston rod protruding from the lower end of this hydraulic cylinder is connected to the bracket provided on the slide. , a screw press in which the auxiliary screw is screwed into the auxiliary female screw provided on the lifting frame. 2. The screwdriver according to claim 1, wherein the hydraulic circuit is configured to recover surplus flywheel energy when the slide stops rising into an accumulator by operating the hydraulic cylinder as a hydraulic brake. press.