JPS63243501A - Two-stage booster - Google Patents

Abstract

PURPOSE:To decrease loss of energy and speedily obtain the optimum condition of clamp in a booster by which an oil pressure is supplied to a clamp means for a tool or the like by discharging a large flow amount of oil with a low pressure in the initial stage where the clamp moves, and generating a high pressure at the terminal stage. CONSTITUTION:A first plunger 15 is actuated by pressurizing a piston 7 in the condition that a first booster cylinder 14 into which the first plunger 15 is inserted and a second booster cylinder 16 in the first plunger 15, into which a second plunger 17 is inserted are filled with fluid. Within the range of a first movement, the second plunger 17 is stopped, and low pressure fluid is discharged through a through-passage provided on the second plunger 17 by virture of the relative movement of the first plunger 15 to the first booster cylinder 14 and the second plunger 17. Further, within the range of a second movement, the fluid is boosted by the movement of the second plunger 17 together with the first plunger 15. Loss of energy is decreased with this arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to pressure intensifiers, and more particularly to pressure intensifiers for supplying hydraulic pressure to clamping means for clamping suitable items such as molds, tools, etc.

BACKGROUND ART Pressure intensifiers are known that include a piston operated by air pressure and a pressure intensifier part connected to the piston and having a plunger of a smaller diameter, and configured to discharge high-pressure liquid from the pressure intensifier part.

In conventional pressure intensifiers, high-pressure liquids such as oil can be supplied by using low-pressure compressed air, which is easily available at factories, by utilizing the area ratio of the piston and plunger. However, the discharge pressure is approximately constant.

High pressure is required during clamping to firmly and reliably clamp items such as molds and tools. With conventional pressure intensifiers, there is no need to supply fluid at the point where a significant flow rate of fluid is required to move the clamp, and only a high pressure needs to be maintained during clamping. Supply liquid. Therefore, it takes time to reach the clamped state, and there are problems such as loss of energy needed to supply high-pressure liquid when unnecessary.

The present invention solves the above-mentioned conventional problems, and maintains high pressure by supplying high-pressure liquid when clamping, but when a large volume of liquid is required to be supplied without requiring particularly high pressure by simply moving the clamping member. The purpose of the present invention is to provide an increased pressure supply that quickly brings the clamped state to a state with less energy loss by having a configuration that allows the supply of low-pressure liquid.

(2) The above object is achieved by a two-stage plunger consisting of a large diameter first plunger connected to a piston and a small diameter second plunger inserted into the first plunger. The first plunger is activated by pressurizing the piston with air pressure from a state in which a first pressure increasing cylinder into which the plunger is inserted and a second pressure increasing cylinder in the first plunger formed to insert the second plunger are filled with liquid. The second plunger is stopped in the first movement range, and the first plunger is moved relative to the first pressure increase cylinder and the second plunger to discharge low pressure liquid through the through passage provided in the second plunger, and the second plunger is moved to a second pressure increase cylinder. In the second movement range after the second plunger is inserted into the cylinder, the second plunger moves into the first position.
This was achieved by a pressure increasing part that moves together with the plunger and is configured to further increase the pressure of the liquid discharged in the first movement range by the amount of movement of the second plunger.

Disastrous boat flame The details of the present invention will be explained based on an embodiment shown in the drawings.

In FIG. 1, a pressure intensifier 1 has an air cylinder part 2 and a pressure intensifier part 3. In FIG.

The air cylinder part 2 has a cylinder casing 6 which is closed at both ends by an air intake end 4 and an intermediate wall 5, and a piston 7 which is slidably guided in the cylinder casing 6. A first inlet/outlet passage 8 is formed in the air suction head 4 , and a second inlet/outlet passage 9 opening into the cylinder casing 6 is formed in the intermediate wall 5 .

The piston 7 is moved by compressed air being supplied through the first inlet/outlet passage 8 and discharged through the second inlet/outlet passage 9 .

The pressure increaser 3 has a pressure increaser casing 11 having, for example, a cylindrical shape, which is closed at both ends by the intermediate wall 5 and the discharge head 10 . A liquid supply path 12 is formed in the ejection head 10 and opens into the pressure intensifying casing 11, and is normally closed.

A drain passage 13 opening into the pressure booster casing 11 is formed in the intermediate wall 5 . A first pressure increase cylinder 14 is provided inside the pressure increase casing 11 and has one end fixed to the intermediate wall 5 and the other end fixed to the discharge head 10 . A first plunger 15 fixed to the piston 7 is inserted into and guided through the intermediate wall 5 into the first pressure boosting cylinder 14 .

A hollow hole 16 is formed in the first plunger 15 as a second pressure increase cylinder, and the second pressure increase cylinder 16 has a second pressure increase cylinder.
One end of plunger 17 is slidably inserted. The other end of the second plunger 17 is slidably guided in a guide hole 18 formed at the end of the first pressure boosting cylinder 14 on the side of the discharge head 10 and a guide hole 19 formed in the discharge head 10 . A large diameter portion 20 is formed at the other end of the second plunger 17, and the end of movement toward the intermediate wall 5 is limited by abutting the ring 21 of the ejection head IO or a receiver attached to the ejection head IO. There is.

A spring 23 is attached to a pressure increasing discharge part 37 formed by an end of the second plunger 17 and a cap 22 screwed onto the discharge head 10, and the second plunger 17 is held pressed at the left end position in the figure. ing.

The first pressure booster cylinder 14 has one or more communication ports 24 formed at the end on the side of the intermediate wall 5 to communicate the internal space of the pressure booster casing 11 and the space inside the first pressure booster cylinder 14, and provides liquid supply. The pressure intensifier casing 1 is supplied through the passage 12.
The liquid contained in the first pressure booster cylinder 14 is easily
This allows it to flow inside.

The first plunger 15 has a free end connected to the first pressure booster cylinder 1.
A flow path 25 is formed that opens into 4.

The other end of the flow path 25 is connected to the second pressure increasing cylinder 16 through a flow path 27 formed in a lid ring 26 that closes the inner end of the second pressure boosting cylinder 16.
It communicates with the inside of the pressure increase cylinder 16. The lid ring 26 is fixed by a presser foot 32 screwed onto the first plunger 15. An abutment plate 28 is fixed to the lid ring 26, with which the end of the second plunger 17 abuts. By screwing the bolt 33 into the presser foot 32, the piston 7 is fixed to the first plunger 15.

The second plunger 17 is provided with a through passage 29 that penetrates in the axial direction. Furthermore, a lid ring 26 is disposed parallel to the through passage 29 to allow liquid to escape when the end of the second plunger 17 comes into contact with the contact plate 28 and the end of the through passage 29 is closed.
It has a bypass passage 31 having a slot 30 communicating with the flow passage 27 .

The operation of this device will be explained.

When compressed air is supplied from the first in/out passage 8 in the initial state shown in FIG. 1, the piston 7 is moved.

The first plunger 15 is urged in accordance with the movement of the piston 7. The first plunger 15 contacts the seal ring 38 installed inside the first pressure booster cylinder 14, and the communication port 24
During the first movement stroke Sl until the first pressure boosting cylinder 14 is cut off, the liquid is not pressurized as shown in the area of stroke Sl in FIG. No liquid is discharged from the discharge passage 34 which communicates with the through passage 29 of No. 17.

As the piston 7 moves further, the eleventh langeer 15 slides within the first pressure booster cylinder 14. At this time, since the first plunger 17 is held stationary by the spring 23, one end of the second plunger 17 moves relatively within the second pressure increasing cylinder 16 formed within the first plunger 15. 1st
During the stroke S3 from when the plunger 15 moves until the end of the second plunger 17 comes into contact with the abutting plate 28, substantially between 53 and 3 lO, the liquid in the second pressure booster cylinder 16 flows through the passage. 29 and is discharged from the discharge passage 34.
The liquid in the pressure booster cylinder 14 is sent into the second pressure booster cylinder 16 through the flow path 25 in the first plunger 15 . At this time, the outer diameter of the piston 7 is d, (area A1), the first
Assuming that the outer diameter of the plunger 15 is dZ (area A2) and the outer diameter of the second plunger 17 is dz (area A3),
The flow rate ■ discharged from the discharge passage 34 is v, =A! (S3-3l), and the hydraulic pressure P is P, = −P, where the air pressure is PA.
.

becomes.

The second plunger 17 is moved together with the first plunger 15 until the end of the second plunger 17 hits the contact plate 28 due to the movement of the stroke S2 and stops after the entire stroke S2 of the rear piston 7 has passed. . At this time, the through passage 29 is sealed by the contact plate 28, so the second
No liquid is ejected through the plunger 17. While the end of the second plunger 17 moves within the cap 22 by the stroke (S2-53), the
(S2 S3) liquid is pressurized. At this time, the hydraulic pressure P2 becomes P2=-PA.

During the first stroke, a large volume of liquid moves the clamping member, etc., and during the subsequent strokes, the clamping pressure is increased to maintain the clamping force.

The movement of the clamp member is finished before the end of the second plunger 17 comes into contact with the first stroke, and when there is no need for liquid supply, the escape of the liquid is bypassed until the end of the second plunger 17 comes into contact. This is done through route 31. That is, excess liquid is transferred to the second pressure booster cylinder 16 and the second pressure booster cylinder 16.
The bypass path 3 is passed through the hole 30 from the gap of the plunger 17.
1 and increases the pressure through a bypass hole 35 communicating with the gap between the second plunger 17 and the first pressure increase cylinder 14 at another position of the bypass passage 31 and an escape hole 36 formed in the first pressure increase cylinder 14. It is discharged into the casing 11.

The amount of liquid in the pressure booster casing 11 is detected by a liquid level gauge 37.

Air is discharged from the second inlet/outlet passage 9 when the piston 7 moves.
This is done by By switching the flow paths, air is supplied through the second inlet/outlet flow path 9, and when the first inlet/output flow path 8 is exhausted, the piston 7 returns to its initial position.

According to the present invention, the discharge pressure and flow rate can be controlled in two stages, such as discharging a large flow rate at low pressure at the beginning of the movement of the clamp, and generating high pressure near the end where clamping force is required. With this configuration, energy loss was small and the optimum clamping state could be quickly achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a pressure intensifier according to the present invention, and FIG. 2 is a diagram showing the relationship between the piston stroke, hydraulic pressure, and discharge amount. 1... Pressure booster 2... Air cylinder part 3...
・Pressure increase part 6...Cylinder casing 7...
Piston 8.9... Inlet/outlet passage IO... Discharge head 11... Pressure booster casing 14... First pressure booster cylinder 15... First plunger 16... Second pressure booster cylinder 17.・Second plunger

Claims (1)

[Claims] In a pressure intensifier that includes a piston operated by air pressure and a pressure intensifier connected to the piston and has a plunger having a smaller diameter than the piston, the plunger discharges high-pressure liquid by the plunger, and the plunger is capable of sealingly housing the liquid. a first plunger slidably guided within the first pressure booster cylinder and connected to the piston; a second pressure booster cylinder formed as a concentric hollow hole of the first plunger; and a second pressure booster cylinder. a second plunger having a protruding end that is slidably guided therein and protrudes from the first pressure boosting cylinder; and a pressure boosting discharge part that accommodates the other end of the protruding end of the second plunger and has a liquid discharge passage. a flow path communicating between the first pressure boosting cylinder and the second pressure boosting cylinder is formed in the first plunger, and a flow path communicating with the first pressure boosting cylinder and the second pressure boosting cylinder is formed in the second plunger.
A through passage communicating between the pressure increase cylinder and the discharge passage is formed, a first plunger moves within the first pressure increase cylinder in a first movement range of the piston, and a second plunger moves within the pressure increase discharge part. It is held stationary by the provided spring and the second
The liquid in the pressure booster cylinder is discharged at a low pressure, and in the second movement range of the piston after the second plunger is inserted into the second pressure booster cylinder, the first plunger and the second plunger move together to remove the already discharged liquid. A two-stage pressure intensifier characterized by further compression.