Internal pressurizing hydraulic oil cylinder

Abstract

The utility model discloses an internal pressurizing hydraulic oil cylinder which comprises a cylinder body, a front cover, a main piston, a pressurizing piston, a rear cover, a one-way valve, a one-way plug, a valve sleeve and a limiting ring, a first cavity and a second cavity are arranged in the cylinder body in a front-back spaced mode, the main piston is arranged in the first cavity, the pressurizing piston is arranged in the second cavity, and the rear cover is arranged in the middle of the cylinder body. The rear cover is arranged at the rear end of the cylinder body, a guide hole communicated with the first cavity and the second cavity is formed in the cylinder body, a second piston rod extending into the guide hole is arranged on the pressurizing piston, a stepped hole extending to the tail end of the pressurizing piston is formed in the front end of the second piston rod in an inward concave mode, and the valve sleeve is arranged at the step position of the stepped hole. The limiting ring is arranged at the front end of the stepped hole, the one-way plug is arranged between the limiting ring and the valve sleeve, and a hollow pipe extending into the stepped hole is arranged at the front end of the rear cover. By means of the mode, the internal pressurizing hydraulic oil cylinder can selectively pressurize, and is compact in structure and flexible to install.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinders, and in particular to an internally pressurized hydraulic cylinder. Background Technology

[0002] During blow molding production, the mold closing cylinder needs to apply a pushing force to the mold. Moreover, the pushing force of the mold closing cylinder must be greater than the blowing pressure inside the mold to ensure the stability of the mold closing state during the blowing process and avoid accidental mold opening problems.

[0003] The thrust of a hydraulic cylinder typically depends on its cylinder diameter and the pressure of the hydraulic system. In blow molding machines, the hydraulic system pressure is generally 12-14 MPa. If a larger thrust is required for mold closing, but the blow molding machine's system pressure cannot be increased, then the only way to ensure sufficient thrust is to increase the cylinder diameter. Increasing the cylinder diameter not only increases costs but also affects the installation of the overall mechanical structure, and reduces the cylinder's movement speed, necessitating improvements. Utility Model Content

[0004] The main technical problem solved by this utility model is to provide an internally pressurized hydraulic cylinder that achieves the effect of internal pressurization, avoids increasing the cylinder diameter, and controls volume and cost.

[0005] To solve the above-mentioned technical problems, the present invention provides a technical solution as follows: An internally pressurized hydraulic cylinder is provided, comprising: a cylinder body, a front cover, a main piston, a booster piston, a rear cover, a one-way valve, a one-way plug, a valve sleeve, and a limiting ring. The cylinder body has a first chamber and a second chamber spaced apart at their front and rear ends. The main piston is disposed in the first chamber, and the booster piston is disposed in the second chamber. The front cover is disposed at the front end of the cylinder body. A first piston rod penetrating the front cover is disposed on the main piston. The rear cover is disposed at the rear end of the cylinder body. A connection between the first chamber and the second chamber is provided within the cylinder body. The guide hole is provided on the booster piston, and a second piston rod is provided on the booster piston. The front end of the second piston rod is recessed and a stepped hole is provided extending to the tail end of the booster piston. The valve sleeve is provided at the step of the stepped hole. The limiting ring is provided at the front end of the stepped hole. The one-way plug is provided between the limiting ring and the valve sleeve. The front end of the rear cover is provided with a hollow tube extending into the stepped hole. The rear cover is provided with a first oil inlet port communicating with the hollow tube on one side or the rear end. The rear cover is provided with a second oil inlet port communicating with the second cavity. The one-way valve is provided in the second oil inlet port.

[0006] In a preferred embodiment of the present invention, a first oil return port communicating with the first cavity is provided on one side of the front cover.

[0007] In a preferred embodiment of the present invention, a second oil return port communicating with the front end of the second cavity is provided on one side of the cylinder body.

[0008] In a preferred embodiment of this utility model, a spring is provided between the one-way plug and the limiting ring.

[0009] In a preferred embodiment of the present invention, the front end of the one-way plug is provided with a guide rod that passes through the limiting ring, and the spring is sleeved on the guide rod.

[0010] In a preferred embodiment of this invention, the diameter of the guide hole is smaller than the diameter of the second cavity.

[0011] In a preferred embodiment of the present invention, the cylinder body is provided with a drain hole communicating with the tail of the first cavity.

[0012] In a preferred embodiment of this utility model, the one-way valve is a normally closed electromagnetic one-way valve.

[0013] The beneficial effects of this utility model are as follows: The internal pressure boosting hydraulic cylinder disclosed in this utility model first supplies oil to the first oil inlet port, and drives the mold of the blow molding machine to close the mold through the movement of the main piston. Then, the oil supply to the first oil inlet port is stopped, and oil is supplied to the second oil inlet port to drive the boosting piston to move, thereby increasing the pressure of the hydraulic oil in the first cavity and ensuring the thrust of the first piston rod. The structure is compact, the installation is flexible, and there is no need to increase the cylinder diameter, thus reducing the cost. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0015] Figure 1 This is a schematic diagram of a preferred embodiment of an internally pressurized hydraulic cylinder in normal state according to the present invention;

[0016] Figure 2 This is a schematic diagram of a preferred embodiment of the internal pressure boosting hydraulic cylinder of the present invention in a pressure boosting state;

[0017] Figure 3 yes Figure 1 A sectional view. Detailed Implementation

[0018] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] Please see Figures 1-3 The embodiments of this utility model include:

[0020] like Figure 1 and Figure 2 The internal booster hydraulic cylinder shown includes: cylinder body 1, front cover 2, main piston 11, booster piston 12, rear cover 4, one-way valve 15, one-way plug 18, valve sleeve 23 and limiting ring 22. The cylinder body 1 has a first cavity 7 and a second cavity 8 arranged at intervals. The cylinder body 1 is provided with a guide hole 9 connecting the first cavity and the second cavity. In this embodiment, the diameter of the guide hole 9 is smaller than the diameter of the second cavity 8. The diameter of the first cavity 7 and the diameter of the second cavity 8 can be the same, which is convenient for processing.

[0021] like Figure 3 As shown, the main piston 11 is disposed in the first cavity 7, the booster piston 12 is disposed in the second cavity 8, and the front cover 2 is disposed at the front end of the cylinder 1. The front cover 2 can be fixed to the front end of the cylinder 1 with screws, and the structure is sturdy. The main piston 11 is provided with a first piston rod 6 that penetrates the front cover 2, and applies a mold closing thrust to the mold of the blow molding machine.

[0022] The rear cover 4 is positioned at the rear end of the cylinder body 1 and can also be fixed with screws, making assembly convenient. A second piston rod 16 extending into the guide hole 9 is provided on the booster piston 12. Figure 1 As shown, the diameter of the booster piston 12 corresponds to the diameter of the second chamber 8, and is much larger than the diameter of the second piston rod 16.

[0023] A stepped hole 21 extending to the tail end of the booster piston 12 is recessed at the front end of the second piston rod 16. The valve sleeve 23 is located at the step of the stepped hole 21, and the step is used to limit the movement of the valve sleeve 23. Figure 2 As shown, the front end of the rear cover 4 is provided with a hollow tube 19 extending into the stepped hole 21. The rear cover 4 is provided with a first oil inlet port 5 communicating with the hollow tube 19 on one side or the rear end. First, oil is supplied to the first oil inlet port 5, and hydraulic oil is introduced into the first cavity 7 through the stepped hole 21, which pushes the main piston 11 to move forward, drives the mold of the blow molding machine to close the mold, and then stops the oil supply to the first oil inlet port 5.

[0024] In this embodiment, a first return oil port 3 communicating with the first cavity 7 is provided on one side of the front cover 2. When the main piston 11 moves forward, the hydraulic oil in the front of the first cavity 7 flows out through the first return oil port 3. The first return oil port 3 can be connected to an external return oil pipe and enter the oil tank of the hydraulic station.

[0025] like Figure 1 As shown, a second oil inlet port 14 communicating with the second cavity 8 is provided on the rear cover 2. A one-way valve 15 is installed in the second oil inlet port 14. The one-way valve 15 can be a normally closed electromagnetic one-way valve, which allows for flexible control. Figure 2 As shown, after stopping the oil supply to the first oil inlet port 5, the oil supply to the second oil inlet port 14 begins. Once the required oil supply pressure is reached, the one-way valve 15 opens, allowing hydraulic oil to enter the second chamber 8 and drive the booster piston 12 to move, thus pressurizing the first chamber 7. When the booster piston 12 retracts, the controller first opens the one-way valve 15, allowing the hydraulic oil in the second chamber 8 to be output through the first oil inlet port 5.

[0026] In this embodiment, the cylinder body 1 is provided with a vent hole 10 that communicates with the tail of the first chamber 7. The vent hole 10 is connected to a safety valve. When the pressure after the first chamber 7 is pressurized is too high, the safety valve opens to release pressure and prevent damage to the cylinder.

[0027] The limiting ring 22 is set at the front end of the stepped hole 21, and the one-way plug 18 is set between the limiting ring 22 and the valve sleeve 23. When the booster piston 12 moves forward to boost the pressure of the first chamber 7, the one-way plug 18 needs to move backward to block the valve sleeve 23.

[0028] like Figure 2 As shown, a spring 20 is provided between the one-way plug 18 and the limiting ring 22. After the oil supply to the first oil inlet port 5 is stopped, the one-way plug 18 is moved backward and reset by the spring 20. In this embodiment, a guide rod 17 penetrating the limiting ring 22 is provided at the front end of the one-way plug 18 to guide the movement of the one-way plug 18. The spring 20 is sleeved on the guide rod 17 to prevent it from falling off and to facilitate assembly.

[0029] A second oil return port 13 is provided on one side of the cylinder body 1, which is connected to the front end of the second chamber 8. The second oil return port 13 can be connected to an external oil return pipe. When the booster piston 12 moves forward, the hydraulic oil in the second chamber 8 enters the oil tank of the hydraulic station.

[0030] In summary, the internal pressure boosting hydraulic cylinder disclosed in this utility model can operate under both normal pressure and pressure boosting conditions, thereby increasing the thrust on the blow molding die and ensuring that the die closing thrust is greater than the blowing pressure inside the die, thus achieving safe production. Moreover, it has a compact structure and is easy to install.

[0031] The above are merely embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An internally pressurized hydraulic cylinder, characterized in that, include: The cylinder comprises a cylinder block, a front cover, a main piston, a booster piston, a rear cover, a one-way valve, a one-way plug, a valve sleeve, and a limiting ring. The cylinder block has a first chamber and a second chamber spaced apart at the front and rear. The main piston is located in the first chamber, and the booster piston is located in the second chamber. The front cover is located at the front end of the cylinder block. The main piston has a first piston rod that penetrates the front cover. The rear cover is located at the rear end of the cylinder block. The cylinder block has a guide hole connecting the first and second chambers. The booster piston has a second piston rod extending into the guide hole. The front end of the second piston rod has a recessed stepped hole extending to the rear end of the booster piston. The valve sleeve is located at the step of the stepped hole. The limiting ring is located at the front end of the stepped hole. The one-way plug is located between the limiting ring and the valve sleeve. The front end of the rear cover has a hollow tube extending into the stepped hole. The rear cover has a first oil inlet port communicating with the hollow tube on one side or at the rear end. The rear cover has a second oil inlet port communicating with the second chamber. The one-way valve is located in the second oil inlet port.

2. The internally pressurized hydraulic cylinder according to claim 1, characterized in that, The front cover has a first oil return port that communicates with the first cavity on one side.

3. The internally pressurized hydraulic cylinder according to claim 1, characterized in that, A second oil return port, which communicates with the front end of the second cavity, is provided on one side of the cylinder.

4. The internally pressurized hydraulic cylinder according to claim 1, characterized in that, A spring is provided between the one-way plug and the limiting ring.

5. The internally pressurized hydraulic cylinder according to claim 4, characterized in that, The one-way plug has a guide rod that passes through the limiting ring at its front end, and the spring is sleeved on the guide rod.

6. The internally pressurized hydraulic cylinder according to claim 1, characterized in that, The diameter of the guide hole is smaller than the diameter of the second cavity.

7. The internally pressurized hydraulic cylinder according to claim 1, characterized in that, The check valve is a normally closed electromagnetic check valve.

8. The internally pressurized hydraulic cylinder according to claim 1, characterized in that, The cylinder body is provided with a drain hole that communicates with the tail of the first cavity.

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