JPS5833923B2 - Hydraulic conversion type high output air cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulically convertible high power air cylinder.

An air press that uses a hydraulic conversion type high-output air cylinder can obtain an output comparable to a hydraulic press that cannot be obtained with a press using only an air cylinder, and can operate at the same speed as an air press during rapid feed. It is characterized by being smaller and lower cost than hydraulic presses.

FIG. 3 is an explanatory diagram showing the configuration of a conventionally used air press of this type, in which 100 is a hydraulic conversion type high-output air cylinder, 101 is a pressure increasing piston, 102 is a pressure increasing valve, and 103 is a rapid feed intermediate play) - 1104 is oil, 105 is a high output ram, 106 is a valve for rapid feed, 107, 108 and 109 are seals between oil and air, 110 is a tie bar, 111 is a slide plate, 11
2 indicates the upper mold.

In this air press, when the rapid feed valve 106 is switched, the oil 100 is removed by the rapid feed intermediate plate 103.
4 is pushed down, and the high-output ram 105 and slide plate 111 descend at high speed.

At this stage, the pressure increase valve 1 is turned on using a preset time switch or position switch.
02 is switched, the pressure increasing piston 101 descends to increase the pressure, and the high output ram 105 performs pressurized feeding while generating high output.

When the command to finish machining is issued from the time switch or the 1-position switch, the pressure increase valve 102 and the rapid feed valve 106 are switched simultaneously, and the pressure increase piston 10
1 and high power ram 105 rise at high speed.

However, this air press cannot have a large cross section to which the return pressure of the high-output ram is applied, so the lifting force of the high-output ram,
In other words, the pulling force is small, and for this reason, it is unsuitable for presses that use slide plates or heavy upper dies, or for work that requires knocking out products. The air that has leaked little by little over a long period of time tends to get mixed into the oil in the pressure booster chamber, and the generated oil pressure tends to be inconsistent. Requires a solenoid valve,
Additionally, a position switch is required to command the switching of the solenoid valve for pressure increase, and the timing adjustment is delicate, requiring readjustment every time the target workpiece changes, which poses problems in terms of economy and workability. was there.

The purpose of the present invention is to eliminate these problems and provide a hydraulic conversion type air cylinder that has a large lifting force of a high-output ram and excellent stability of generated oil pressure. A hydraulic conversion type high-output air cylinder having an air cylinder for rapid rod feeding, and a hydraulic cylinder having a high-output ram that descends together with the piston rod during the rapid feeding and increases pressure when subjected to a constant load. In the hydraulic cylinder,
It has an intermediate cylinder that moves up and down together with the piston rod, and the piston rod and the high output ram are engaged through an elastic body that urges the piston rod to maintain a predetermined distance when the piston rod is rapidly moved, and the high output The ram and the intermediate cylinder are comprised of a double-structured hydraulic cylinder that moves up and down as a unit by engaging via an elastic body that urges the piston rod to come into close contact with each other when the piston rod is rapidly moved. A high hydraulic pressure generating chamber for pressure increase, which is formed by communicating a space formed by the output ram and a space formed by the high output ram and the intermediate cylinder, and is provided between the hydraulic cylinder and the intermediate cylinder. It is characterized by having an intermediate hydraulic chamber for pressure increase connected to an oil tank with constant hydraulic pressure via an air check valve.

That is, the present invention achieves the objective by employing a double-structured hydraulic cylinder and a pilot check valve mechanism in a hydraulic conversion type high-output air cylinder that performs rapid feed with an air cylinder and increases pressure with a hydraulic cylinder. That is.

Examples will be described below.

FIG. 1 and FIG. 2 show a cross section of one embodiment.
FIG. 1 shows a state in which the high power ram of the air cylinder is raised and in a fixed position, and FIG. 2 shows a state in which the high power ram is lowered and output is generated.

In these figures, 1 is an air cylinder, which has a piston 2 that moves up and down and a piston rod 3. The inside of the piston rod 3 is hollow and is filled with oil 4, and its tip is filled with oil 4. It serves as an inlet and an air vent, and is sealed by a load cell 5.

Reference numeral 6 denotes a hydraulic cylinder, which has a flange with a tightening hole for fixing to a column, etc. Inside the hydraulic cylinder 6, there is an intermediate cylinder 7 that moves up and down together with the piston rod 3, and a high-output ram 8. The intermediate cylinder 7 and the high output ram 8 are moved up and down together by a spring 9 which serves to press the high output ram 8 against the intermediate cylinder 7.

The interior of the high output ram 8 is a high oil pressure generation chamber 10 filled with oil 4, and a spring 11 that pushes down the high output ram 8 and the intermediate cylinder 7.
is provided.

Note that a screw is machined at the tip of the high-output ram 8, so that it can be attached to a mold or a tool.

12 is an air pilot check valve, inside of which is a pilot piston 1 operated by air pressure and a spring 13.
4. It is composed of a check valve 16 that is opened and closed by a spring 15 and a pilot piston 14, and a valve seat 17, and is the most important valve that opens and closes the flow of oil to the intermediate hydraulic chamber 20.

18 is a balance cylinder, the inside of which is filled with oil 19 along with an intermediate hydraulic chamber 20, and a constant pressure is applied by the action of a balance piston 21 and a spring 22.

The tip of the balance piston 21 serves as an oil 19 inlet and an air vent, and is sealed with a plug 23 and completely isolated from air.

When this hydraulic conversion type high-output air cylinder operates, first, with the high-output ram shown in FIG. At the same time that air is supplied from port A, port B provided in the hydraulic cylinder 6 and pilot cylinder cover 25 is opened to the outside air.

Therefore, the pilot piston 14 is pushed back by the spring 13 and the check valve 16 is closed by the spring 15, so that the oil supply path in the balance cylinder 18 to the intermediate hydraulic chamber 20 is closed, and this state At this point, the piston 2 and piston rod 3 rapidly descend.

At this time, the force of the spring 11 provided at the tip of the piston rod 3 and the spring 9 provided between the intermediate cylinder 7 and the high-output ram 8 causes a certain constant load to be applied. Since the oil 4 in the high oil pressure generation chamber 10 cannot move, the intermediate cylinder 7 and the high output ram 8 rapidly descend together with the piston rod 3 while being in close contact with each other.

As the intermediate cylinder 7 descends, the intermediate hydraulic chamber 20 located between the hydraulic cylinder 6 and the intermediate cylinder 7 becomes negative pressure, so that the balance cylinder 1
The oil 19 in 8 pushes open the check valve 16 and flows into the intermediate hydraulic chamber 20.

The balance piston 21 and the spring 22 function to assist the movement of the oil 19.

When the intermediate cylinder 7 and the high-output ram 8, which have rapidly descended together with the piston rod 3, hit the workpiece (or stopper), the oil 4 in the high oil pressure generation chamber 10 is further pressurized by the cylinder rod 3, which is further descending. hand,
The high pressure flows into the high pressure cylinder chamber 26 located between the intermediate cylinder 7 and the high output ram 8, generating a force that raises the intermediate cylinder 7. Trying to force it to flow back inward.

However, the check valve 16 is in close contact with the valve seat 17,
In order to block the backflow of the oil 19 and momentarily lock the upward movement of the intermediate cylinder 7,
The high-pressure oil 4 flowing into the ram 6 has a high output and pushes down the high-output ram 8, resulting in the state shown in FIG. 2, and the workpiece is machined by the set mold or the like.

Note that the output of the high-output ram 8 can be directly checked with the load meter 5 (or pressure gauge) on the top of the piston rod 3, so linked operation can be easily achieved by connecting a pressure switch, etc. can do.

When the work is completed with high output generated as described above, the solenoid valve etc. is switched again by the preset time switch or pressure switch, etc., and the air pressure is simultaneously applied to the hydraulic cylinder 6 and port B of the pilot cylinder cover 25. When the piston 2 and the piston rod 3 are supplied and the port 1-A of the cylinder cover 24 is opened, the piston 2 and the piston rod 3 move upward rapidly.

The high-output ram 8 is pulled up by the step of the Rondo diameter located at the lower end of the piston rod 3, and the intermediate cylinder 7 is successively pulled up by the high-output ram 8, rapidly rising to the fixed position shown in FIG.

At that time, the oil 4 in the high pressure cylinder chamber 26 passes through the gap between the piston rod 3 and the high output ram 8,
The oil 19 in the intermediate hydraulic chamber 20 is returned to the high pressure generation chamber 10 and is returned to the balance cylinder 18 through the check valve 16 which is opened via the pilot piston 14.

As explained above, the hydraulic conversion type high-output air cylinder of this embodiment is a pneumatic cylinder that uses compressed air, which is relatively easy to handle and low in cost, as its operating source, and has a system that converts the air pressure into hydraulic pressure and increases the pressure. Yes, the lifting force of the high-power ram is equal to the lifting force of the air cylinder, so
The high-output ram has a large lifting force, making it possible to perform press operations using heavy upper dies.

In addition, because it uses a double-layered hydraulic cylinder and a pilot check valve mechanism, it is possible to switch between high-speed feed and pressurized feed with just one operating valve (4-way switching valve). Since the structure is such that the output ram automatically switches to pressurized feed when it hits the workpiece, etc., the electric circuit, air circuit, etc. are extremely simple, and continuous automatic operation is also extremely easy.

Furthermore, it has a double-layered hydraulic cylinder and two independent oil tanks, and the oil is completely isolated from the air, so there is no chance of air getting mixed into the oil, and the structure eliminates the cause of pressure drop. Because air does not dissolve into oil, it prevents oil deterioration and consumption, and greatly improves operating speed and stability of generated oil pressure, resulting in stable high output comparable to oil pressure. Maintenance and management such as pouring and replenishing oil into the oil tank and venting air are easy, and
It is economical both in terms of price and footprint.

Therefore, when this hydraulic conversion type high-output air cylinder is used in small presses, etc., it is possible to perform operations such as caulking, punching, bending, and wrinkles that require high output, which are considered relatively difficult with conventional air presses. It becomes possible to provide an economical press etc. that can be easily carried out and has stable and high workability.

As described above, the hydraulic conversion type high-output air cylinder of the present invention makes it possible to provide this type of device in which the high-output ram has a large lifting force and the generated oil pressure is excellent in stability, and has industrial effects. It's a dog.

[Brief explanation of drawings]

Figures 1 and 2 are sectional views showing different states of an embodiment of the hydraulic conversion type high-output air cylinder of the present invention, and Figure 3 is a press using a conventional hydraulic conversion type high-output air cylinder. FIG. 1... Air cylinder 2... Piston, 3... Piston rod, 4...
Oil, 5...Load cell, 6...Hydraulic cylinder 7...Intermediate cylinder, 8...
・High output ram, 9... Spring, 10...
High oil pressure generation chamber, 11... Spring, 12...
・Air pilot check valve, 13... Spring, 14... Pilot piston, 15...
...Spring, 16...Check valve, 17...
...Valve seat, 18...Balance cylinder
19... Oil, 20... Intermediate hydraulic chamber, 21... Balance piston, 22...
- Wings, 23...Plug, 24...Cylinder cover 25...Pilot cylinder cover 26...High pressure cylinder chamber.

Claims (1)

[Claims] 1. An air cylinder for rapid movement of the piston rod using compressed air as an operating source, and a hydraulic cylinder having a high-output ram that descends together with the piston rod during the rapid movement and performs a pressure-increasing action when subjected to a load on the gait. In the hydraulic conversion type high-output air cylinder, the hydraulic cylinder has an intermediate cylinder 7 that moves up and down together with the piston rod, and the piston rod and the high-output ram 8 are arranged at a predetermined interval when the piston rod is rapidly moved. The high-output ram and the intermediate cylinder are engaged through an elastic body that urges the piston rod to come into close contact with each other when the piston rod is rapidly moved, so that the high-output ram and the intermediate cylinder become integral. The hydraulic cylinder has a double structure that moves up and down, and the space formed by the piston rod and the high-output ram communicates with the space formed by the high-output ram and the intermediate cylinder. It is characterized by having a high oil pressure generation chamber and an intermediate oil pressure chamber for pressure increase that is provided between the hydraulic cylinder and the intermediate cylinder and is connected to an oil tank with constant oil pressure via an air check valve. Hydraulic conversion type high output air cylinder.