JPS6025240B2 - High pressure hydraulic press equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic press device that can press a mold at high pressure.

For example, conventional high-pressure hydraulic press equipment that presses and molds powder, etc., uses a pressure device in the middle of the piping that connects the hydraulic pump and the cylinder ram of the press equipment body, so that high pressure can be obtained during molding. However, this requires additional installation space for the pressure intensifier and also requires piping that can withstand high pressure, which has the drawback of being easily damaged.

In order to eliminate these shortcomings,
No. 94 (name of invention: Forming die operating device in press equipment) is also known, in which a pressure intensifier is formed inside the cylinder ram, but according to this conventional improvement measure, vertical movement The problem is that the piping from the hydraulic pump must be connected to the pressure plate (also called the upper mold pressure block) for mounting the upper mold, which cannot be configured without using flexible piping such as rubber pipes. Therefore, it was not necessarily sufficient as a reinforcement measure against damage. In contrast, the applicant of the present patent has already applied for a high-pressure hydraulic press device in Japanese Patent Application No. 55-125361 (Japanese Patent Publication No. 59-122638) in order to solve the above-mentioned drawbacks, but the present invention has the same purpose. It is an object of the present invention to further improve the invention, and one embodiment of a high-pressure hydraulic press apparatus according to the present invention will be described below with reference to the drawings. A frame 1 is supported horizontally by columns (not shown) vertically erected on a device base (not shown), and 2
indicates a pressure plate to which the upper mold of the mold is fixed.

The pressure plate 2 and the frame 1 are connected via a pair of sub-cylinders 3, 3 made to have a small diameter for high-speed operation, and a hydraulic power source ( When low pressure oil is supplied from a switching valve (not shown) through a switching valve (not shown), the pistons of the sub cylinders 3, 3 move, causing the pressure plate 2 to move up and down at high speed. 6
is a large-diameter cylinder hole formed in the center of the frame, and a large-diameter main ram 7 fixed vertically on the pressure plate 2 is loosely inserted into the large-diameter cylinder hole. A main pressurizing chamber 8 is formed on the main ram 7 by the cylinder hole 6 and the main ram 7. Reference numeral 9 denotes an auxiliary oil tank, and 10 denotes an oil supply chamber formed on the frame 1 so as to constantly communicate with the main pressurizing chamber 8. A surge valve 12 faces a lotus through hole 11 formed in the side wall of the oil supply chamber. There is.

The lotus through hole 11 is in continuous communication with the auxiliary oil tank 9. A shaft 13 of the surge valve 12 is disposed in a casing 14 so as to be movable laterally, and a small piston 1 is attached to a part of the shaft 13.
5 is formed, and an adjusting screw 16 is screwed onto the end protruding from the casing 14, and a coil spring 17 is interposed between the adjusting screw 16 and the outer surface of the casing 14. Therefore, the surge valve 12 is normally operated by the coil spring 1.
The lotus passage through the lotus passage hole 11 is blocked by the elasticity of the lotus passage 7. A hydraulic chamber 18 for opening the surge valve 12 against the elasticity of the coil spring 17 is located in the casing 14.
When low-pressure oil is supplied to the hydraulic chamber 18 from the pipe 19, the small piston 15 receives the pressure and the shaft 13 moves to the left in the figure. will open. Furthermore, a pressure increasing cylinder is installed above the oil supply chamber 10 concentrically with the main ram 7, 21 is a pressure increasing piston loosely inserted into the pressure increasing cylinder 20,
The tip of the piston shaft 23 further projects through the oil supply chamber 10 into the main pressurizing chamber 8, and the tip of the piston shaft 23 is long enough to come into contact with the upper surface of the main ram 7. .

22 is a pipe connected to the upper end of the pressure increasing cylinder 20;
The pipe 22 is connected to a hydraulic pressure source via a switching valve (not shown), so that low pressure oil is supplied thereto.

Reference numeral 24 denotes an air vent hole communicated at the lower end of the pressure increasing cylinder 20.

In the high-pressure hydraulic press device configured in this way, first, the piping 4 of the sub-cylinders 3, 3 is supplied with oil, and the pressure plate 2 is rapidly lowered, and the upper mold (not shown) attached to the pressure plate 2 is lowered. ) is attached to the lower die (not shown).

At this time, the main pressurizing chamber 8 becomes negative pressure due to the lowering of the main ram 7, and the surge valve 12 resists the elasticity of the coil spring 17 to move the main pressurizing chamber 8 into the oil supply chamber 10.
Since the oil is absorbed inward, the oil in the auxiliary oil tank 9 is sucked into the main pressurizing chamber 8 through the opened through hole 11 (this state is shown in FIG. 2). Next, piping 22
When low pressure oil is supplied from the upper end of the lump pressure cylinder 20 through the cylinder 20, the pressure increasing piston 21 is lowered by the oil pressure, and the tip of the piston shaft 23 projects into the main pressurizing chamber 8.
That is, the main pressurizing chamber 8 and the oil supply chamber 10 are filled with oil, and as the piston shaft 23 further enters therein, the volume of the chamber increases, the hydraulic pressure increases, and the main ram 7 is compressed at a high pressure. . In other words, since the diameter of the piston shaft 23 is smaller than that of the main ram 7, the pressure is increased by the entry of the piston shaft 23, and the main ram 7 descends. Therefore, pressure plate 2
The upper mold attached to the mold is pressed down onto the lower mold under high pressure, and the desired molded object can be pressure-molded (this state is shown in FIG. 3). After the molding is completed, the hydraulic chamber 1 is inserted through the pipe 19.
8, the surge valve 12 is opened, and the main pressurizing chamber 8 and the auxiliary oil tank 9 are allowed to communicate with each other.
After that, low pressure oil is supplied to the pipe 5 and the sub cylinder 3
, 3 are contracted and the pressurizing plate 2 is raised, the oil filled in the main pressurizing chamber 8 is returned to the auxiliary oil tank 9 as the main ram 7 rises, and at the same time, the oil is returned to the upper surface of the main ram 7. Since the tip of the piston shaft 23 comes into contact with the main ram 7 and raises the piston shaft 23, the pressure increasing piston 21 can also be raised and returned to the state shown in FIG. 1.
Therefore, by repeating this operation, the desired molded product can be pressed at high pressure. As described above with respect to the embodiments, the high-pressure hydraulic press device according to the present invention has a pressure increasing cylinder vertically installed above the oil supply chamber formed on the frame, and the tip of the piston shaft of the pressure increasing cylinder is inserted into the main pressurizing chamber. Since the pressure increasing cylinder is made to protrude, there is no need to use flexible hydraulic piping connected to the pressure increasing cylinder, and the hydraulic piping has excellent durability.

In addition, the tip of the piston shaft of the pressure increase cylinder is configured so that it can come into contact with the upper surface of the main ram, so that as the main ram is returned by the operation of the sub-cylinder, the piston shaft is also returned. It is possible to provide a hydraulic press device that is compact, has a greatly simplified configuration, does not require hydraulic piping for return, and can obtain high pressurizing force. Furthermore, since the surge valve is installed horizontally on the side wall of the oil supply chamber, the structure is simplified and costs are reduced, and the coil spring of the surge valve can be easily inspected.

[Brief explanation of the drawing]

The drawings show an embodiment of the high-pressure hydraulic press device according to the present invention, and FIGS. 1 to 3 are schematic longitudinal cross-sectional views showing the operating state, and FIG. 4 is an enlarged view of the main parts of FIG. 1. It is a diagram. 1... Frame, 2... Pressure plate, 3, 3.
...Sub cylinder, 6...Oyo silling hole, 7...Main ram, 8...Main pressurizing chamber, 9...Auxiliary oil tank, 10...・Refueling room, 11...
...Communication hole, 12...Surge valve, 20...
... Pressure increase cylinder, 21 ... Pressure increase piston, 23 ... Piston shaft. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A pressure plate is arranged in a frame so as to be movable up and down via a sub-cylinder made with a small diameter for high-speed operation, a large diameter cylinder hole is formed in the center of the frame, and a pressure plate is installed in the large diameter cylinder hole. A main ram fixed perpendicularly to the frame is loosely inserted so that the large diameter cylinder hole and the main ram constitute a main pressurizing chamber, and an oil supply chamber is provided on the frame, which is in constant communication with the main pressurizing chamber. A surge valve is provided horizontally on the side wall of the oil supply chamber so that communication between the main pressurizing chamber and the auxiliary oil tank is interrupted by opening and closing of the surge valve, and a surge valve is provided above the oil supply chamber. A pressure increasing cylinder is installed vertically, and the tip of the piston shaft of the pressure increasing cylinder projects into the main pressurizing chamber through the oil supply chamber, so that the tip of the piston shaft can come into contact with the upper surface of the main ram. A high-pressure hydraulic press device that features the following features: