Negative-pressure oil supplementing rapid oil cylinder

Abstract

The utility model discloses a negative pressure oil supplementing rapid oil cylinder which comprises a cylinder body, a limiting structure is fixedly arranged in an inner cavity of the cylinder body, and the limiting structure divides the inner cavity of the cylinder body into a piston cavity and a liquid supplementing cavity. A piston rod is arranged in the piston cavity in a sliding fit mode, and a piston block at the inner end of the piston rod divides the piston cavity into a boosting cavity and a retreating cavity. The cylinder body is provided with a front inlet, an oil conveying channel is arranged in the limiting structure, and the front inlet is connected with an inner cavity of the piston rod through the oil conveying channel. The cylinder body is provided with a liquid supplementing opening, the liquid supplementing opening is connected with a liquid supplementing oil tank through a liquid filling valve, and the liquid supplementing opening is connected with the liquid supplementing cavity; the limiting structure is provided with a plurality of oil inlet channels, and the liquid supplementing cavity is connected with the boosting cavity through the multiple oil inlet channels. The cylinder body is provided with a back-off opening, and the back-off opening is connected with the back-off cavity; and the front inlet and the return opening are connected with a hydraulic system. Rapid movement of the hydraulic cylinder is achieved through a small-flow hydraulic system.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder technology, and in particular to a negative pressure oil replenishment rapid hydraulic cylinder. Background Technology

[0002] Hydraulic cylinders are common actuators in power systems. Their movements are controlled by a hydraulic system. In some applications, there are high requirements for the movement speed of the hydraulic cylinders. For example, the drive cylinders of presses need to be pressed into place quickly and held under a certain pressure for a period of time to ensure molding quality. Therefore, presses often use high-speed hydraulic cylinders. To achieve the rapid movement of the hydraulic cylinder, common high-speed hydraulic cylinders usually use a high-flow hydraulic system for oil supply, and the working energy consumption of the oil pump is relatively large. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a negative pressure oil replenishment rapid hydraulic cylinder, which uses a small flow hydraulic system to achieve rapid movement of the hydraulic cylinder.

[0004] Technical solution: To achieve the above objectives, the present invention provides a negative pressure oil replenishment rapid oil cylinder, including a cylinder body, wherein a limiting structure is fixedly provided in the inner cavity of the cylinder body, and the limiting structure separates the inner cavity of the cylinder body into a piston cavity and a replenishment cavity;

[0005] A piston rod is slidably fitted inside the piston chamber, and a piston block at the inner end of the piston rod divides the piston chamber into a boost chamber and a retraction chamber.

[0006] The cylinder block is provided with a front inlet, and the limiting structure is provided with an oil supply channel. The front inlet is connected to the piston rod cavity through the oil supply channel.

[0007] The cylinder body is provided with a fluid inlet, which is connected to the fluid tank via a filling valve and is also connected to the fluid filling chamber.

[0008] The limiting structure is provided with several oil inlet channels, and the fluid replenishment chamber is connected to the booster chamber through multiple oil inlet channels.

[0009] The cylinder body is provided with a retraction port, which is connected to the retraction chamber;

[0010] The front inlet and the return port are connected to the hydraulic system.

[0011] Furthermore, the limiting structure includes a limiting block and a guide rod. The limiting block is axially limited and fixed relative to the inner wall of the cylinder. The guide rod is fixedly disposed at the center of the limiting block and is disposed along the cylinder axis. The guide rod is inserted and fitted into the inner cavity of the piston rod.

[0012] Furthermore, the filling valve includes a filling chamber, the lower opening of which is connected to the replenishment port. A valve core is provided at the opening, and the valve core is connected to a drive block via a lifting rod. The drive block is slidably fitted within a vertical guide cavity. A return spring is provided between the lower part of the drive block and the lower end face of the vertical guide cavity. The filling chamber is connected to the replenishment tank.

[0013] Furthermore, the chamber on the upper side of the drive block within the vertical guide slide cavity is connected to the hydraulic system via a pilot pressure port.

[0014] Furthermore, the cylinder body is provided with a pressure port, and the hydraulic system is connected to the fluid replenishment chamber through the pressure port.

[0015] Furthermore, the outlet of the oil delivery channel is located at the center of the end face of the guide rod, and multiple oil inlet channels are arranged on the limiting block, with the multiple oil inlet channels evenly distributed around the guide rod.

[0016] Beneficial effects: The negative pressure oil replenishing rapid oil cylinder of this utility model, through the cylinder structure design, allows the hydraulic system to actively provide a small amount of oil for pushing the piston rod to move, pressurize, retract, and for opening the filling valve during retraction. Most of the oil is replenished quickly through the negative pressure suction generated by the piston movement and gravity. No additional power source is required, so the entire hydraulic cylinder system can achieve rapid movement of the cylinder with only a small flow hydraulic system, reducing the working energy consumption of the hydraulic system oil pump. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a negative pressure oil replenishment rapid oil cylinder according to the present invention;

[0018] Figure 2 This is a schematic diagram of the filling valve structure according to one embodiment of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] As attached Figure 1-2 The aforementioned negative pressure oil replenishment rapid oil cylinder includes a cylinder body 1, wherein a limiting structure 2 is fixedly provided in the inner cavity of the cylinder body 1, and the limiting structure 2 divides the inner cavity of the cylinder body into a piston cavity and a replenishment cavity 11.

[0021] The limiting structure 2 includes a limiting block 21 and a guide rod 22. The limiting block 21 is axially limited and fixed relative to the inner wall of the cylinder 1. The guide rod 22 is fixedly arranged at the center of the limiting block 21 and is arranged along the cylinder axis.

[0022] A piston rod 3 is slidably fitted inside the piston chamber. The piston rod 3 is an integrated structure of piston and rod body. The piston block at the inner end of the piston rod 3 divides the piston chamber into a boost chamber 12 and a retraction chamber 13. The boost chamber 12 is located between the limiting block 21 and the upper end face of the piston rod 3. The retraction chamber surrounds the outside of the piston rod and is located between the lower end face of the piston and the lower end face of the cylinder inner cavity.

[0023] The piston rod 3 has an inner cavity 31 formed at the center of its upper end face along its axis, and the guide rod 22 is inserted into the inner cavity 31 of the piston rod.

[0024] The cylinder body 1 is provided with a front inlet 14, and the limiting structure 2 is provided with an oil supply channel 23. The front inlet 14 is connected to the piston rod inner cavity 31 through the oil supply channel 23. The outlet of the oil supply channel 23 is located at the center of the end face of the guide rod 22, which allows the hydraulic oil pumped in by the front inlet to act directly on the center position of the end face of the piston rod inner cavity, so as to ensure that the piston rod is subjected to uniform force relative to its forward direction, reduce energy waste, and make full use of hydraulic energy to increase the movement speed of the piston rod. Preferably, the oil supply channel 23 is arranged along the central axis of the guide rod 22, and the oil inlet end is connected to the front inlet on the cylinder body through a radial channel opened in the limiting block 21. The front inlet 14 is connected to the hydraulic system.

[0025] The cylinder body 1 is provided with a fluid inlet 15, which is connected to the fluid tank via a filling valve 4 and is also connected to the fluid filling chamber 11. The limiting structure 2 is provided with several oil inlet channels 24, and the fluid filling chamber 11 is connected to the booster chamber 12 via these channels. Oil is supplied to the front inlet via the hydraulic system, pushing the piston rod to slide forward along the guide rod. Due to the movement of the piston rod, the booster chamber 12 and the fluid filling chamber 11 form a negative pressure chamber, thereby opening the filling valve 4 and drawing oil from the fluid tank into the cylinder body, quickly filling the fluid filling chamber 11 and the booster chamber 12. This achieves rapid movement and pressurization of the hydraulic cylinder using a small-flow hydraulic system, resulting in a simple structure and low cost.

[0026] Preferably, multiple oil inlet channels 24 are disposed on the limiting block 21, and the multiple oil inlet channels 24 are evenly distributed around the guide rod 22. This ensures that during replenishment, the oil can enter the booster chamber evenly from the replenishment chamber, thereby acting evenly on the upper end face of the piston rod. This further ensures that the direction of force on the piston rod is consistent with the direction of piston rod movement, and that the overall force is uniform, ensuring the stability of the piston rod movement, improving the hydraulic energy conversion rate, and further reducing the required flow rate of the hydraulic system.

[0027] The cylinder body 1 is provided with a retraction port 17, which is connected to the retraction chamber 13 and to a hydraulic system. Oil is supplied to the retraction port by the hydraulic system, thereby increasing the oil pressure in the retraction chamber, which in turn pushes the piston rod back. The piston's force-bearing surface in the retraction chamber is relatively small, thus ensuring rapid retraction of the piston rod.

[0028] The filling valve 4 includes a filling chamber 41, the lower opening of which is connected to the replenishment port 15. A valve core 43 is disposed at the opening, and the valve core 43 is connected to a drive block 44 via a lifting rod. The drive block 44 is slidably disposed within a vertical guide cavity 45. A return spring 46 is disposed between the lower part of the drive block 44 and the lower end face of the vertical guide cavity 45. The filling chamber 41 is connected to the replenishment oil tank. After the piston rod moves to form a negative pressure chamber, a pressure difference is generated between the upper and lower sides of the valve core, which compresses the return spring and moves the valve core downward away from the lower opening of the filling chamber 41. This allows the oil in the replenishment oil tank to be drawn into the filling chamber 41. Under the combined action of negative pressure suction and gravity, the oil enters the replenishment chamber 11 from the lower port of the filling chamber 41, thereby achieving rapid replenishment, significantly reducing the energy consumption of the active pump, and thus greatly reducing the required flow rate of the hydraulic system.

[0029] As attached Figure 2 As shown, preferably, the replenishing oil tank is connected to the filling chamber 41 through an annular guide hole. The annular guide hole is sleeved on the outside of the vertical guide cavity. The replenishing oil tank is placed directly above the entire oil cylinder. Before the valve core is opened, the oil fills the entire filling chamber 41 under the action of gravity. When the piston rod moves and generates negative pressure, the valve core can open immediately, making the oil replenishment action extremely fast. At the moment of opening, the oil quickly enters the replenishing chamber 11 under the action of gravity. In the entire replenishment process, the oil is simultaneously affected by gravity and negative pressure suction, thereby achieving rapid oil replenishment.

[0030] Within the vertical guide cavity 45, the chamber on the upper side of the drive block 44 is connected to the hydraulic system via a pilot pressure port 42. Preferably, the external port of the pilot pressure port 42 can be located on the side wall of the cylinder tail end cap, communicating with the upper chamber of the drive block via an internal oil guide channel. When the piston rod retracts, the hydraulic system actively supplies oil to the pilot pressure port, allowing hydraulic oil to enter the upper chamber of the drive block, thereby pushing the drive block downwards and actively opening the filling valve core. This allows some of the oil on the upper side of the piston rod to return to the replenishment tank via the filling valve for subsequent rapid oil replenishment.

[0031] The cylinder body 1 is provided with a pressure port 16, and the hydraulic system is connected to the replenishing chamber 11 through the pressure port 16. When the piston rod is driven to its limit position by the front inlet oil and the filling valve is closed, oil is supplied to the pressure port through the hydraulic system, which further increases the oil pressure in the replenishing chamber 11 and the booster chamber 12, further realizing the rapid movement of the piston rod. When the piston rod reaches its extension limit position, pressure is applied to stabilize the position of the piston rod. This is suitable for the drive hydraulic cylinder of the press, which can realize the rapid stamping of the pressed parts and hold the pressure at a certain intensity for a period of time, thereby obtaining excellent stamping effect. During retraction, except for the oil that returns from the filling valve to the replenishing oil tank, the remaining oil can return to the system oil tank of the hydraulic system through the pressure port and the front inlet.

[0032] Based on the above-described hydraulic cylinder structure, the specific workflow is as follows:

[0033] First, the hydraulic system supplies oil to the forward inlet, which enters the piston rod's inner cavity and pushes the piston rod to move. A negative pressure is formed on the upper side of the piston rod, causing the filling valve core to open. The negative pressure suction draws oil from the replenishment tank into the filling chamber. Then, under the combined action of gravity and suction, the oil enters the upper chamber of the piston rod, achieving rapid replenishment. When the pressure on both sides of the valve core is balanced, the valve core resets, and the filling valve closes. At the same time, the hydraulic system supplies oil to the pressure port, increasing the pressure on the upper side of the piston rod, causing the piston rod to move rapidly to its limit position and remain stable.

[0034] During retraction, the solenoid valve reverses direction, and the hydraulic system simultaneously supplies oil to the pilot pressure port and the retraction port, causing the filling valve to open. Under the reverse push of the piston rod, the oil on the upper side of the piston retracts through the front inlet and the pressurization port to the system oil tank of the hydraulic system, and then retracts through the filling valve to the replenishment oil tank.

[0035] Because the space inside the piston rod is small, the amount of hydraulic oil pumped in to complete the entire stroke of the piston rod is small. Meanwhile, a large amount of hydraulic oil in the larger cavity on the upper side of the piston rod is quickly replenished through negative pressure suction and gravity, and a small amount is pressurized through system replenishment. In addition, the hydraulic oil has a small working surface during retraction, requiring less oil, and the amount of oil required to drive the filling valve to open is also small. Therefore, the amount of oil required for the hydraulic system supply is small, which allows the cylinder to move quickly using a small flow hydraulic system. In practical applications, this can effectively reduce energy consumption, especially in applications such as presses that involve frequent high-speed movements.

[0036] The above are merely preferred embodiments of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A negative pressure oil replenishment rapid oil cylinder, characterized in that: Includes a cylinder body (1), wherein a limiting structure (2) is fixedly provided in the inner cavity of the cylinder body (1), and the limiting structure (2) separates the inner cavity of the cylinder body into a piston cavity and a liquid replenishment cavity (11); A piston rod (3) is slidably fitted inside the piston chamber, and the piston block at the inner end of the piston rod (3) divides the piston chamber into a boost chamber (12) and a retraction chamber (13); The cylinder body (1) is provided with a front inlet (14), and the limiting structure (2) is provided with an oil supply channel (23). The front inlet (14) is connected to the piston rod cavity (31) through the oil supply channel (23). The cylinder body (1) is provided with a liquid replenishment port (15), which is connected to the liquid replenishment tank through a filling valve (4) and is connected to the liquid replenishment chamber (11); The limiting structure (2) is provided with a plurality of oil inlet channels (24), and the replenishment chamber (11) is connected to the booster chamber (12) through the plurality of oil inlet channels (24); The cylinder body (1) is provided with a return port (17), which is connected to the return cavity (13); The front inlet (14) and the return port (17) are connected to the hydraulic system.

2. The negative pressure oil replenishment rapid oil cylinder according to claim 1, characterized in that: The limiting structure (2) includes a limiting block (21) and a guide rod (22). The limiting block (21) is axially limited and fixed relative to the inner wall of the cylinder (1). The guide rod (22) is fixedly arranged at the center of the limiting block (21). The guide rod (22) is arranged along the cylinder axis. The guide rod (22) is inserted into the inner cavity (31) of the piston rod.

3. The negative pressure oil replenishment rapid oil cylinder according to claim 2, characterized in that: The filling valve (4) includes a filling chamber (41), the lower opening of which is connected to the replenishment port (15). A valve core (43) is provided at the opening. The valve core (43) is connected to a drive block (44) via a lifting rod. The drive block (44) is slidably fitted in a vertical guide cavity (45). A return spring (46) is provided between the lower part of the drive block (44) and the lower end face of the vertical guide cavity (45). The filling chamber (41) is connected to the replenishment tank.

4. The negative pressure oil replenishment rapid oil cylinder according to claim 3, characterized in that: The chamber on the upper side of the drive block (44) inside the vertical guide slide cavity (45) is connected to the hydraulic system through the pilot pressure port (42).

5. A negative pressure oil replenishment rapid oil cylinder according to claim 4, characterized in that: The cylinder (1) is provided with a pressure port (16), and the hydraulic system is connected to the fluid replenishment chamber (11) through the pressure port (16).

6. A negative pressure oil replenishment rapid oil cylinder according to claim 5, characterized in that: The outlet of the oil delivery channel (23) is located at the center of the end face of the guide rod (22), and a plurality of oil inlet channels (24) are arranged on the limiting block (21), and the plurality of oil inlet channels (24) are evenly distributed around the guide rod (22).

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