JPH0340503Y2 - - Google Patents

Description

[Detailed description of the invention] The invention relates to a hydraulic circuit in a shearing machine, and more specifically, when surge pressure occurs in a pipe connected to a fluid pressure source, the high pressure of the surge pressure is used to hold the plate down, and The present invention relates to a hydraulic circuit in a shearing machine that can suppress noise caused by surge pressure.

First, the background of the invention will be explained with reference to FIGS. 1 and 2.

The shearing machine 1 shown in FIG. 1 includes a table 5 in front of a frame 3 (on the right side in FIG. 1), and a lower blade 7 at the rear end of the table 5.

A ram 11 that moves up and down in an arc around the shaft 9 is provided on the side plate of the frame 3, and the ram 11 has an upper blade 1 at its lower front end that engages with the lower blade 7 described above.
It has 3.

The ram 11 is driven by a plurality of single-acting hydraulic cylinders 15 swingably mounted above the frame 3.

The upper part of the frame 3 extends above the table 5 above the gap part 17, and an appropriate number of plate holding devices 21 equipped with single-acting hydraulic cylinders 19 (see Figs. 2 and 3) are installed in this part. It is provided.

The plate holding block 23 of the plate holding device 21 has the role of pressing the workpiece W positioned on the table 5 between it and the table 5.

Conventionally, a hydraulic circuit for driving the shearing machine 1 as described above was as shown in FIG.

That is, the pump P serving as a fluid pressure source feeds hydraulic oil from the oil tank T into the pipe line 25 and pressurized oil into the pipe line 29 via the solenoid switching valve 27 .

A relief valve 31 is provided in the conduit 25.

When this hydraulic oil is guided to an appropriate number of fluid pressure cylinders 19 of the plate holding device 21, each fluid pressure cylinder 19
When the plate holding blocks 23 of all the plate holding devices 21 are lowered by overcoming the counter biasing force of the bullets 33 built into the table 5 and fix the workpiece W to be cut between them and the upper surface of the table 5, a shock wave P appears on the oil pressure gauge PG. ₁ (surge pressure) is displayed.

This shock wave _P1 is guided to the fluid pressure cylinder 15 that drives the ram 11 by opening the sequence valve 35, so the pulsating pressure including high pressure passes through narrow parts such as the orifice of the sequence valve 35, so that the hydraulic oil is The high temperatures caused them to age in a short period of time, and they also produced noise, among other inconveniences.

The present invention was devised for the purpose of solving the above-mentioned disadvantages of the conventional circuit, and will be explained in detail below based on the embodiment circuit shown in FIG.

In the circuit of this embodiment, a first pilot operating valve 37 is provided between the pipe line 29 through which the pressurized fluid from the fluid pressure source P passes through the solenoid switching valve 27 and the single acting fluid pressure cylinder 19 of the plate holding device 21. , a second pilot operating valve 39 is provided between the first pilot operating valve 37 and the single acting hydraulic cylinder 15 of the ram 11 in parallel.

The pilot operating valves 37 and 39, as shown in FIG. The opening/closing rod 47 is a special check valve that opens and closes the pressure oil flow path by the added pressure of both rods, and has the feature that the opening and closing operations of the flow path described above are performed quickly.

Note that the hydraulic circuit may also be used to release the fixation of the workpiece W on the table 5 and raise the ram 11 to return.
A third pilot operating valve 51 and a fourth pilot operating valve 53 are provided, which are equipped with a projectile 49 having a weak biasing force.
The hydraulic pressure of the plate holding device 21 is guided to a pilot line 55 via a solenoid switching valve 57.

The order in which the material to be cut W is cut by the shearing machine 1 equipped with the above-described embodiment circuit is as follows.

Before starting work, the solenoid SOL1 of the solenoid switching valve 27 is in the OFF state, and the solenoid SOL2 of the solenoid switching valve 57 is in the ON state.

Therefore, the pressure oil from the pump P, which is the oil pressure source, is returned to the oil tank T with low flow resistance, and the pressure oil in the pilot pipe 55 is also guided to the oil tank T. As a result, pressure oil and ram 1 are supplied to the plate holding device 21.
The pressure oil that lowers the ram 1 is also pushed by the ram 33 and the ram 11 that raises and returns the ram 11, and the ram 49 has a weak urging force.
is compressed, and the third and fourth pilot operating valves 51,
53 is opened and the oil is drained into the oil tank T.

That is, both the ram 11 and the plate holding device 21 are located at their upper limits.

Position the workpiece W on the table 5, and turn on the solenoid using a foot switch (not shown) or the like.
Turn on SOL1 and turn off solenoid SOL2.

Pressure oil from the pump P, which is the oil pressure source, reaches the pipe 29 and is preliminarily connected to the bomb 41 of the first pilot operating valve 37.
The biasing force of the bomb 4 of the second pilot operating valve 39
Since the biasing force is set to be weaker than the urging force of the first pilot operating valve 37, the pressure oil acts on the end face of the opening/closing rod 47 of the first pilot operating valve 37, pushing the opening/closing rod 47 against the bomb 41 and opening it. , pressure oil passes through and operates the plate holding device 21.

The third pilot operating valve 51 and the fourth pilot operating valve 53 have the lower pressure from the pressure oil added to the biasing force of the ammunition 49, so the oil tank T
The flow path to is closed.

In this way, all the plate holding blocks 23 of the plate holding devices 21 provided in an appropriate number come to fix the workpiece W on the table 5.

Then, the pressure of the pressure oil led to the plate holding device 21 increases, and the pressure on the secondary side acts as pilot pressure on the head side of the piston 45 of the first pilot operating valve 37 via the pilot pipe line 43. , the opening/closing rod 47 is under pressure, the first pilot operating valve 37 is closed, and the pressure oil in the pipe line 29 flows into the fluid pressure cylinder 15 that drives the ram 11 via the second pilot operating valve 39, and the ram 11 is lowered. let

When the ram 11 has descended and finished cutting the workpiece W between the upper blade 13 and the lower blade 7, turning off the foot switch will turn off the solenoid SOL1.
OFF, solenoid SOL2 switches to ON.

Therefore, all the pressure oil that drove the plate holding device 21 and the ram 11 is drained from the third pilot operating valve 51 and the fourth pilot operating valve 53 to the oil tank T, and the state is restored to the state before the start of work.

In the course of the sequence operation described above, when the plate holding blocks 23 of the plate holding device 21 fix the workpieces W to be cut all at once, a pulsating pressure (surge pressure) is generated in the conduit 29.

This surge pressure momentarily opens the once-closed first pilot operation valve 37 and is guided to the pilot pipe line 43, so that the high pressure of the surge pressure is held in the cylinder 19, and the pressing force of the plate holding device 21 is increased. becomes more powerful. On the other hand, the width of the pulsation of the pressure oil guided to the second pilot operation valve 39 is reduced, and the elastic force 41 of the second pilot operation valve 39 also acts, so that the pressure oil with a small height difference is transferred to the second pilot operation valve 39.
will pass through.

Thus, in the pressure oil circuit of this embodiment, the pressure oil with a small height difference is passed through the second pilot operating valve 39 which has low flow resistance and operates quickly, so that the hydraulic oil is not heated unnecessarily and aged. This has the effect of preventing noise caused by surge pressure, and eliminates the inconveniences of conventional devices.

As shown in FIGS. 4, 5, and 6, this shearing machine 1 includes a rotating body 59 that is made of non-ferrous metal and has a substantially semi-cylindrical lower surface at the upper end of the ram 11, and a piston rod 61 of the fluid pressure cylinder 15 on the upper surface of the rotating body 59. A connecting member 65 equipped with a non-ferrous metal rocking plate 63 that is in contact with the lower end of the
is provided.

As shown in FIG. 1, the ram 11 rotates around the shaft 9 and moves up and down, and the piston rod 61 of the fluid pressure cylinder 15 moves linearly by expanding and contracting.
The connecting member 65 has the role of connecting the ram 11 and the piston rod 61, which move differently.

Therefore, for example, an X-shaped oil groove 67 is formed on the outer circumference of the rotating body 59, and a similar oil groove 69 is also formed on the upper surface of the sliding plate 63.

As is clear from the figure, an elbow 71 is provided on one side of the rotating body 59, through which lubricant is fed from a grease pump (not shown), and vertical and horizontal roads 75, 77 are provided inside the connecting member 65. The oil is led to oil grooves 67, 69, in which a vertical channel 75 is provided at an angle of about 10 degrees with respect to the central axis of the ram 11, as shown in FIG.

As described above, the piston rod 61 and the upper end of the ram 11 are connected by surface contact through the connecting member 65, which includes the sliding plate 63 made of non-ferrous metal and the rotating body 59, so there is no contact between the so-called sliding parts. This means that "galling" does not occur.

As can be understood from the above description of the embodiments, the gist of the present invention is as stated in the claims for utility model registration.As is clear from the description, the present invention uses a fluid pressure source. The pipe line 29 connected to the cylinder 19 of the plate holding device 21
A first pilot operated valve 3 is installed in the oil passage connecting the
7 is arranged, and the pipe line 29 and the ram 11
A second pilot operating valve 39 is disposed in an oil passage connecting the cylinder 15 for raising and lowering the cylinder.
The first and second pilot operating valves 37 and 39 have the same configuration, and are larger than the opening/closing rod 47 and the opening/closing rod 47, which can freely open and close each oil passage and receive the pressure in the pipeline 29 at its end face. It is equipped with a piston 45 that is integral in diameter and a bullet 41 that urges the opening/closing rod 47 in the closing direction, and the head side of the piston 45 is connected to the secondary side.
The urging force is weaker on the first pilot operating valve 37 side.

Therefore, according to the present invention, when the working fluid is supplied to the pipe line 29, first the first pilot operating valve 37 is brought into communication, and the cylinder 19 of the plate holding device 21 is operated. When the pressure inside the cylinder 19 reaches a predetermined value or higher, the second pilot operating valve 39 is brought into communication, and the cylinder 15 for raising and lowering the ram 11 is operated. When surge pressure is generated in the pipe line 29, the first pilot operation valve 37 side, which has a weak biasing force of the bomb 41, is opened, and high pressure acts on the cylinder 19 of the plate holding device 21, and the pressure is maintained at high pressure. After this, the second pilot operation valve 39 is opened, and the plate holding action is more strongly maintained, and
The surge pressure passing through the second pilot operating valve 39 is alleviated, and noise due to the surge pressure can be prevented.

It is also clear that the design can be easily changed without departing from the technical idea of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a side view of a shearing machine embodying the present invention, Fig. 2 is a conventional hydraulic circuit diagram, Fig. 3 is a hydraulic circuit diagram of an embodiment of the present invention, Fig. 4 is an illustration of the installation of the connecting member, and Fig. 5 The figure is an enlarged central sectional view of the same as the above, and FIG. 6 is a side view of the same. Explanation of symbols representing main parts of the drawings: 1... Shearing machine, 15... Ram fluid pressure cylinder, 19...
Fluid pressure cylinder for plate holding, 21... plate holding device,
37...First pilot operating valve, 39...Second pilot operating valve, 43...Pilot conduit, 47
...Opening/closing rod.

Claims (1)

[Scope of utility model registration request] Pipe line 29 connected to a fluid pressure source and plate holding device 21
A first pilot operating valve 37 is arranged and provided in the oil line connecting the cylinder 19 to the pipe line 29.
A second pilot operating valve 39 is disposed in an oil passage connecting the cylinder 15 and the cylinder 15 for raising and lowering the ram 11.
Reference numerals 7 and 39 each include an opening/closing rod 47 which can freely open and close each of the oil passages and which receives the hydraulic pressure in the pipe 29 at its end face, and a piston 45 which has a larger diameter than the opening/closing rod 47 and is integrated with the opening/closing rod 47. ,
and a bomb 41 that urges the opening/closing rod 47 in the closing direction.
is provided internally, and the head side of the piston 45 is connected to the secondary side, so that the biasing force of the bullet 41 provided in the first pilot operating valve 37 is provided in the second pilot operating valve 39. A hydraulic circuit for a shearing machine, characterized in that the biasing force is weaker than that of a projectile.