JPS61282609A - Press cylinder - Google Patents

Abstract

PURPOSE:To facilitate the operation by connecting rooms of each cylinder to a fluid source through a four ports/three positions switching valve after providing a double acting cylinder with a large bore and a double acting cylinder with a small bore continuously. CONSTITUTION:A double acting cylinder 1 with a large bore and a small stroke and a double acting cylinder 4 with a small bore and a large stroke are provided continuously, and the first cylinder room 6 and the second cylinder room 9, of the double acting cylinder 1 with a large bore are respectively, connected to the first cylinder room 7 and the second cylinder room 10 of the double acting cylinder 2 with a small bore, and then a fluid source 13 is connected to each cylinder room 6, 7, 9, 10 through a four ports/three positions directional control valve 12. Hereby, a press cylinder can be driven with the only operation of the four ports/three positions directional control valve 12, therefore the operation can be made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a press cylinder, which is a function often required in forging and casting machines in particular, to drive a short stroke with a large pressure and then drive a long stroke with a small pressure. It was created for a two-stage press cylinder that had the function of being driven by the press cylinder.

In conventional technology forging and casting machines, press cylinders are used as an important element, but normal double-acting cylinders that simply operate with a constant stroke and constant pressure by supplying pressure oil are disadvantageous in terms of working time, etc. Due to this inconvenience, it is desired to adopt a two-stage press cylinder.

For example, in a casting apparatus as shown in FIG. 8, a supply path 102 for molten metal is provided in the table lot from below, and a mold 103 corresponding to an upper mold is pressed against the table 101 to supply the molten metal. Mold 10 through channel 102
A hole 103a extends from the core to the top of the casting mold 103, and after the molten metal has cooled to some extent in the mold 103, it is poured from the table 101 into the mold. 103 is removed upwards, and in the process of moving upward, a rod 104a provided on the base 104 is inserted into the hole 103a, leaving the molded product on the table 101, and finally the sweeper This mold 1 extrudes the product laterally by 105.
03 is operated by the press cylinder 106 mounted on the base 104, but the press cylinder 1
Using a conventional double-acting cylinder for 06 will result in pressure and working time disadvantages. This is because in the initial stage of pulling the mold 103 upward in this process, when the molten metal shrinks due to cooling and is molded into a product, it becomes difficult to separate from the mold 103, and the rod 104a is forced to push the product down. A strong force is required, but once the product has been pushed down, a relatively light force is sufficient. Rather, it is necessary to quickly move on to the next operation while pushing the product to the side with the sweeper lO5. This is because, although it is reasonable to increase the pressure, a normal double-acting cylinder can only operate at a constant pressure and constant speed if the supply of pressure oil is constant.

In response to this request, the
The invention shown in 2008 discloses a "two-stage cylinder device" as shown in FIG.

This device operates as follows.

From port lO8 of cylinder body 107 to cylinder chamber 10
When pressurized oil is supplied to the cylinder 9, the piston 110 is pushed upward with strong pressure inside the cylinder body 107, and the cylinder chamber 1
The operating cylinder 112 and working rod 113 that are in contact with each other on the 11 side are also pushed upward. Here, the oil in the cylinder chamber 111 flows out through the bow 114.

When the piston 110 moves to the uppermost position inside the cylinder body 107, the piston 110 moves from the port l15 provided in the working rod 113 to the cylinder chamber 117 through the flow path 11B bored in the shaft of the working rod 113. Supply pressure oil.

Then, the piston 113a provided on the working rod 113 inside the working cylinder 112 is pushed upward, and the working rod 113 is pushed upward. Here, the oil in the cylinder chamber 118 flows out through the port l19.

In the above process, the working rod 113 is quickly pushed upward, first with strong pressure and then with light pressure.

On the other hand, in order to return to the original state, ports 108 and 115 may be placed in a drain state, and pressure oil may be supplied from ports 114 and 119.

Therefore, this device meets the functional requirements of the above-mentioned casting machines and the like.

Problems to be Solved by the Invention However, the "two-stage cylinder device" shown in Japanese Patent Publication No. 56-48008 has the advantage that it can be made small compared to the stroke size of the working rod 113 by using the actuating cylinder 112. On the other hand, the mechanism is complicated, there are many sealing parts, the hole 113a must be drilled inside the working rod 113, which makes machining troublesome, and the working rod 113 has holes (115). Since it is provided,
Technical problems have been pointed out, such as the large movement of the port 115 during operation, which is likely to cause oil leakage.

The present invention was created with the aim of solving the problems of the prior art described above and providing a two-stage press cylinder suitable for casting equipment that can be operated with simple operation.

Means for Solving the Problems The basic concept of this invention will be explained with reference to FIG. In the figure, l is a large-diameter double-acting cylinder, the axial length of the cylinder chamber in this cylinder l is short, and the large-diameter piston 2 operates within the cylinder 1 only with a relatively short stroke.

A small-diameter double-acting cylinder 4 is connected to the rod 3 of the large-diameter piston 2 . This small-diameter double-acting cylinder 4 is a single-rod type, and its cylinder chamber has a long axial length, so that the small-diameter piston 5 can operate within the cylinder 4 with a long stroke.

A flow path 8 leading to the first cylinder chamber 6 of the large-diameter double-acting cylinder 1 and the first cylinder chamber 7 of the small-diameter double-acting cylinder 4, and a second cylinder chamber 9 of the large-diameter double-acting cylinder l and the small-diameter A fluid source 13 is connected to a flow path 11 leading to the second cylinder chamber 10 of the double-acting cylinder 4 via a four-bottom, three-position switching valve 12 .

In the figure, 14 is a working rod, which serves to transmit the pressure drive of this press cylinder to the outside.

In addition, in the figure, flow paths 8 and 11 are connected to each cylinder 1 and 4.
Although depicted externally, it is optional to configure them within the cylinder tubes of cylinders 1 and 4.

Operation Next, the operating state of the press cylinder of the present invention will be explained using FIGS. 2 to 5. Figure 2 shows the working rod 14.
indicates the most retracted state, and from this state, when pressure oil is supplied to each of the first cylinder chambers 6 and 7 of the large-diameter double-acting cylinder 1 and the small-diameter double-acting cylinder 4 through the flow path 8, one working rod 14 This is because a large force Fa is applied in the opposite direction to the rod extension direction at the beginning of the drive.

The small diameter piston 5 is not driven, and only the large diameter piston 2 is driven inside the large diameter double acting cylinder l. This is because the pressure-receiving area of the small-diameter piston 5 is smaller than that of the large-diameter piston 2, and the small-diameter piston 5 can be driven against the force Fa. Due to the driving force generated by the large-diameter piston 2 receiving pressure,
This is because it is possible to drive against the force Fa for the first time.

In this state, the air flows out from the second cylinder chambers 9 and 10 of the large-diameter double-acting cylinder 1 and the small-diameter double-acting cylinder 4 through the flow path 11. If pressure oil is continued to be supplied from the initial drive state shown in FIG. 2, the large diameter piston 2 will move as much as possible within the large diameter double acting cylinder l.

By this stage, the force Fa in the opposite direction to the extension direction of the working rod 14 has become light, and if that force is Fb, then the small diameter piston 5 resists the force Fb and enters the small diameter double acting cylinder 4. will be driven. This state is shown in FIG. 3, and pressure oil continues to be supplied to each of the first cylinder chambers 6 and 7 through the flow path 8, but in the first cylinder chamber 6, the large diameter piston 2 has moved to the maximum, so that The pressure oil does not flow into the first cylinder chamber 6, but only into the first cylinder chamber 7, causing the small-diameter piston 5 to move at a relatively high speed within the small-diameter double-acting cylinder 4. 14 is rapidly ejected. In this way, the working rod 14 is fully ejected, as shown in FIG. 4, and the rod ejection process is now complete. Therefore, in the ejection process,
The working rod 14 is driven at low speed and strong pressure in the initial stage of driving against force Fa, and then after the drag force Fa changes to a smaller drag force Fb, it is driven at high speed and low pressure. In order to restore the state from the maximum protrusion shown in FIG. 4 to the original state shown in FIG. and 10, at this stage there is almost no external force applied to the working rod 14, so the large-diameter piston 2 and the small-diameter piston 5 quickly return inside the respective cylinders 1 and 4 in the direction in which the working rod 14 is pulled in. This will result in a standby state for the primary ejection driving operation. The supply of pressure oil in one or more processes is controlled by operating a 4-port, 3-position switching valve 12 provided between the flow paths 8 and 11 and the fluid source 13.

Embodiment Next, an embodiment of the press cylinder of the present invention will be explained with reference to FIGS. 6 and 7. In FIG. The direction length is short, and the large diameter piston 16 fitted in the cylinder 15 can only operate with a short stroke.This large diameter double acting cylinder 15 is provided with ports 17 and 18, and these ports The large-diameter piston 16 is operated by supplying pressure oil to the rod 19 of the large-diameter piston 16, and a small-diameter double-acting cylinder 2 is connected to the rod 19 of the large-diameter piston 16.
0 is connected, but this small-diameter double-acting cylinder 20 is a single-rod type, and the axial length of its cylinder chamber is long, and the small-diameter piston 21 fitted in the same cylinder 20 has a long stroke inside the cylinder. It can be operated with. It should be noted that the connecting portion between the rod 19 and the small-diameter double-acting cylinder 20 does not need to be fixed, and may have a detachable structure. This small-diameter double-acting cylinder 20 is provided with ports 22 and 23, and the small-diameter piston 21 is actuated by supplying pressure oil to these ports.

Among the ports of each cylinder 15 and 20, ports 17 and 22 pass through the flow path 24, and ports 18 and 23 pass through the flow path 24.
It is connected to a 4-port 3-position switching valve 27 provided intermediately leading to the fluid source 26 through the fluid source 26 .

In the figure, 2B is a working rod, and the small diameter piston 2
The operation process of the press cylinder in this embodiment is the same as that described in the above operation, and is a single rod connected to the press cylinder 1 and plays the role of transmitting the pressure drive of this press cylinder to the outside. Switching valve 2
7 to supply pressure oil to the ports 17 and 22 through the flow path 24, move the working rod 28, which is subjected to a large resistance, by the strong initial drive of the large diameter piston 16, and then reduce the resistance by the initial drive. The working rod 28 is quickly pushed out by high-speed driving of the small-diameter piston 21, and conversely, the process of retracting the working rod 28 is performed by operating the 4-port 3-position switching valve 27 to connect the working rod 28 through the flow path 25 to the ports 1B and 23.
This is done by supplying pressure oil to the pistons 16 and 21 and quickly retracting both pistons 16 and 21.

Effects of the Invention The press cylinder of the present invention is most suitable for shortening the working time in casting equipment, forging equipment, etc., and has the following technical effects compared to the prior art.

■ The mechanism is simple, there are fewer seals, and a conventional general seal for the cylinder is sufficient.

■ No processing is required on the working rod, making production easier.

■ Since there is no need to provide a port on the working rod, piping is simplified and the movement of the port during operation is extremely reduced, eliminating the causes of failures due to oil leakage, etc.

■ Easy to operate as all you need to do is operate the 4-port 3-position switching valve.

Furthermore, if the connection between the large-diameter piston rod and the small-diameter cylinder is made removable, each cylinder can be easily replaced from the outside, and the pressure receiving area and stroke can be adjusted to suit the application. This has the advantage of being able to replace the existing cylinder, making it extremely convenient.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic concept of this invention, and FIGS. 2 to 5 are simplified sectional views showing the operating state.
FIG. 6 is a sectional view showing one embodiment of the present invention, FIG. 7 is a sectional view taken along the line A-A in FIG. 6, FIG. 8 is a sectional view showing the basic concept of the casting device, and FIG. 9 shows a cross-sectional view of the main parts of a conventional "two-stage cylinder device". In each figure, 1 is a large-diameter double-acting cylinder, 2 is a large-diameter piston, 3 is a rod, 4 is a small-diameter double-acting cylinder, 5 is a small-diameter piston, 6 is the first cylinder chamber of a large-diameter double-acting cylinder,
7 is a first cylinder chamber of a small-diameter double-acting cylinder; 8 is a flow path;
9 is the second cylinder chamber of the large-diameter double-acting cylinder, 10 is the second cylinder chamber of the small-diameter double-acting cylinder, 11 is the flow path, 12 is the 4-port 3-position switching valve, 13 is the fluid source, and 14 is for work. Rod, 15 is a large diameter double acting cylinder, 16 is a large diameter piston, 17 and 18 are ports, 19 is a rod, 20 is a small diameter double acting cylinder, 21 is a small diameter piston, 22 and 23 are ports, 24 and 25 are 26 is a fluid source. 27 indicates a 4-port 3-position switching valve, and 28 indicates a working rod. Figure 1 Figure 3 Figure 5

Claims (1)

[Claims] In cylinders that drive short strokes with high pressure and long strokes with small pressure, a relatively short stroke and large diameter double acting cylinder rod is used, and a relatively long stroke and small diameter single rod type double acting cylinder. The cylinders are connected in series, and a flow path leading to a first cylinder chamber of the large diameter double acting cylinder and a first cylinder chamber of the small diameter single rod type double acting cylinder, and a second cylinder chamber of the large diameter double acting cylinder and the small diameter A press cylinder characterized in that a fluid source is connected to a flow path leading to a second cylinder chamber of the single-rod type double-acting cylinder via a four-port three-position switching valve.