JPS6334799Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure medium supply and discharge device for a cold isostatic pressing device used in powder molding and the like.

In pressure molding of powder, cold isostatic pressure is used to supply hydrostatic pressure into a high pressure molding container and pressure mold the powder charged into the container, as is known as a rubber press. Pressure devices are often used as a wet press means for powder bodies.

The pressure pattern in this pressurizing device is as shown in Fig. 1. It is necessary to perform pressurization A, pressure holding B after pressurization, and then perform primary depressurization C and secondary depressurization D. It is important to prevent the occurrence of cracks in the molded product by controlling the secondary reduced pressure D.

From this point of view, the applicant of this case
The present invention has been attracting attention in the industry by providing a pressure reduction method and device as disclosed in the above publication, and aiming to put them into practical use.

However, in the above-mentioned conventional example, a pressure medium-hydraulic opposing cylinder is provided, and a pump for increasing the pressure and a pump for decreasing the pressure are required, making the equipment expensive in terms of equipment and structure.

Therefore, the present invention aims to simplify the equipment and structure by sharing the pressure pump and the pressure reduction pump, and at the same time, a worm reducer is installed to prevent rotational force from being transmitted to the motor due to the back pressure applied to the pump during pressure reduction. It is equipped to ensure that secondary depressurization can be carried out.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

2 to 4 show a first embodiment of the present invention, in which 1 is a pressure vessel of a cold isostatic pressurizing device, into which a molded object 2 such as powder is charged. ing.

Reference numeral 3 denotes a pressure medium supply/discharge device, which applies hydrostatic pressure isotropically to the inside of the pressure vessel 1 through its supply/discharge port 1A.

The pressure medium supply and discharge device 3 is constructed as follows.

Reference numeral 4 designates a pump for supplying and discharging pressure medium, which is exemplified as a plunger type consisting of a cylinder tube 4A and a plunger 4B.

Reference numeral 5 denotes a boosting motor, which is interlocked and connected to the pump 4 via a clutch 6. That is, a plunger 4B is connected to the crank 7 via a connecting rod 4C.

Reference numeral 8 denotes a pressure reducing motor, which is operatively connected to the pump 4 via a clutch 9 and a worm reducer 10.

11 is a pressure medium circuit, which connects the discharge side of the pump 4 and the supply/discharge port 1A of the pressure vessel 1;
The circuit 11 is equipped with a switching valve mechanism 12 and a primary pressure reducing valve mechanism 13.

14 is a feedback mechanism, which has a pressure detector 17 connected to the circuit 11 between the switching valve mechanism 12 and the primary pressure reducing valve mechanism 13, and controls the rotational speed of the pressure reducing motor 8. The signal is now being fed back.

The circuit 11 of this embodiment is based on the cylinder tube 4A.
A pressure increasing valve 12 is installed in each branched pipe line.
A and a pressure reducing valve 12B are provided to constitute a switching valve mechanism 12, and a pressure increasing valve 12A is provided.
A pipe line 20 leading to the tank 19 via the check valve 18, and a pipe branching from between the check valve 18 and the pressure increasing valve 12A of the pipe line 20 and leading to the pressure vessel 1 via the check valve 21. a check valve 23 branched from between the pressure vessel 1 and the check valve 21 of the pipe line 22;
A pipe line 2 leading to the pressure reducing valve 12B via
4, the check valve 23 of the pipe line 24, and the pressure reducing valve 1
2B and communicates with the tank 19 via a depressurizing valve 25, and a conduit 27 extending from the pressure vessel 1 to the tank 19 via the primary pressure reducing valve mechanism 13. has been done.

Thus, the pressure relief valve 25 is connected to the cylinder tube 2.
5A is fitted with a valve rod 25C having a piston 25B, and the piston 25B side communicates with the aforementioned pipe 24 via a pipe 28, and the pipe 28 and the pipe 26
When the pressures are the same, the piston 25B and the valve stem 2
The pipe 26 is closed due to the area difference with 5C, and the pipe 26
It is configured to open when the pressure in the pipe line 28 becomes higher than that in the pipe line 28.

To explain the effects of supplying and discharging the pressure medium in the first embodiment, that is, pressurization A, holding B, primary depressurization C, and secondary depressurization D, Fig. 2 shows the process of pressurization A; By starting the motor 5 and operating the pump 4 via the clutch 6, the pressure medium is transferred to the pressure increasing valve 12A of the switching valve mechanism 12.
By turning on, the check valve 21 is pushed open and the water is supplied into the pressure vessel 1 via the pipe line 22.
As shown in FIG. 1, the object 2 to be formed is isotropically pressure-formed by undergoing the pressure increasing step A for a predetermined period of time.

After passing through the holding B process, the primary depressurization C
The primary pressure reduction C is performed by turning off the primary pressure reduction valve mechanism 13 as shown in the third figure.

After this primary depressurization process C, a transition is made to a secondary depressurization process D, and this secondary depressurization pattern is particularly important from the viewpoint of preventing product cracks.

Therefore, as shown in FIG. 4, the pump 4 is
, the pressure reducing valve 12B is turned on, the pressure in the circuit 11, specifically the pipe line 24, is detected by the detector 15 and amplified via the amplifier 16, and the control signal from the pressure reducing pattern setting device 17 is detected. By controlling the rotational speed of the pressure reduction motor 8, the pressure reduction speed (including both primary and secondary, but especially secondary) can be controlled.

In the case of secondary pressure reduction, the pressure medium is discharged into the tank 19 via the pressure relief valve 25.

FIG. 5 shows a second embodiment, in which a gear pump is adopted as the pump 4, and when the pressure is increased, the pump is rotated in the normal direction.
In other words, the pump is driven in the direction of liquid delivery, and when the pressure is reduced, the pump is reversed.When the pressure is reduced, back pressure is applied to the pump and the pump shaft is rotated, so a worm reducer is installed in the middle. 10 is provided to prevent the rotational force of the pump from being transmitted to the motor, which is the same as in the first embodiment.

In summary, in the present invention, in a pressure medium supply and discharge device that supplies and discharges pressure medium into the pressure vessel 1 of a cold isostatic pressurization device, the clutch 6 is connected to the pump 14 for pressure medium supply and discharge. A boost motor 5 is interlocked and connected to the pump 4 via a clutch 9 and a worm reducer 1.
A pressure reducing motor 8 is interlocked and connected via a pressure reducing motor 8, and a switching valve mechanism 12 and a primary pressure reducing valve mechanism 13 are connected to a pressure medium circuit 11 connecting the discharge side of the pump 4 and the inside of the pressure vessel 1. are respectively provided, and the switching valve mechanism 1 of the circuit 11
A feedback mechanism 14 having a pressure detector 15 and a pressure reduction pattern setter 17 is provided between the pressure reduction valve mechanism 2 and the primary pressure reduction valve mechanism 13, and the feedback mechanism 14 is connected to the pressure reduction motor 8. Since the present invention relates to a pressure medium supply and discharge device for a cold isostatic pressurization device, it has the following advantages.

Since the pump 4 can be used both for pressure increase and pressure reduction, the structure can be simplified.

Even if the pump 4 is shared for pressure increase and pressure reduction, the pump 4 and the pressure reduction motor 8 are connected to the clutch 9.
Since they are connected via the worm reducer 10, the load of the pump 4 is not transmitted.

Since the pressure reduction motor 8 is controlled via the feedback mechanism 14, the pressure reduction pattern can be optimally set and controlled.

Note that when a plunger type pump 4 is used, there may be a plurality of pumps, and the pressure reducing motor 8 needs to be able to control the rotation speed, but may be an AC motor or a DC motor.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the pressure pattern of the cold isostatic pressurizing device, Figs. 2 to 4 show the first embodiment of the present invention, Fig. 2 is a configuration diagram during pressurization, and Fig. 3 is the primary The configuration diagram during depressurization, Figure 4 is the configuration diagram during secondary depressurization,
FIG. 5 is a block diagram of the second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Pressure vessel, 4... Pump, 5... Boosting motor, 6, 9... Clutch, 8... Pressure reduction motor, 10... Worm speed reducer, 11... Circuit, 1
2... Switching valve mechanism, 13... Valve mechanism for primary pressure reduction, 14... Feedback mechanism, 15...
...Pressure detector, 17...Decompression pattern setting device.

Claims (1)

[Scope of Claim for Utility Model Registration] In a pressure medium supply/discharge device for supplying and discharging pressure medium into a pressure vessel 1 of a cold isostatic pressurizing device, A boost motor 5 is interlocked and connected to the pump 4, as well as a clutch 9 and a worm reducer 10.
A decompression motor 8 is interlocked and connected via the
Furthermore, a switching valve mechanism 12 and a primary pressure reducing valve mechanism 13 are respectively provided in the pressure medium circuit 11 that connects the discharge side of the pump 4 and the inside of the pressure vessel 1. A pressure detector 15 is installed between the pressure reducing valve mechanism 13 and
1. A pressure medium supply and discharge device for a cold isostatic pressurization apparatus, characterized in that a feedback mechanism 14 having a pressure reduction pattern setter 17 and a pressure reduction pattern setter 17 is provided, and the feedback mechanism 14 is connected to the pressure reduction motor 8.