Hydraulic system for continuous working of movable hydraulic clamp and control method

Abstract

The invention discloses a hydraulic system for continuous working of a movable hydraulic clamp, which comprises an oil supply part and a clamping control part, and the oil supply part provides oil for the clamping control part. The oil supply part and the clamping control part can be selectively separated; the clamping control part comprises a clamp oil cylinder, a one-way valve, an energy accumulator and an oil receiving tank; the one-way valve is connected with the clamp oil cylinder through a second oil way, and a three-position four-way reversing valve and an oil cylinder reversing valve are installed on the second oil way. The one-way valve is connected with the energy accumulator through an oil path III; the one-way valve is connected with the oil receiving tank through a fourth oil way, and a liquid flow valve is installed on the fourth oil way. And the oil receiving tank and the one-way valve are respectively connected with the oil supply part through respective oil paths. Continuous multi-time clamping can be completed, and light and heavy clamping can be achieved for workpieces with different thicknesses and hardness.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic systems, and more specifically, relates to a hydraulic system and a control method for a movable hydraulic clamp that works continuously. Background Art

[0002] Hydraulic clamps are often used in forging machinery and are used for clamping that needs to be maintained for a long time. Since the hydraulic valve will have internal leakage, if the oil pump motor does not continuously supply oil, the clamping force will be reduced; if the oil is continuously supplied, the oil temperature will rise, and the energy consumption will be high and the noise will be loud. In the prior art, there is an accumulator connected to the rodless area of ​​the oil cylinder (such as Figure 2 In actual use, the following problems may occur:

[0003] 1. Each time the clamp is clamped, the accumulator must be filled before it can be clamped. When the clamp cylinder is released, the oil in the accumulator must be drained before the clamp cylinder can be released. This will reduce work efficiency and waste energy.

[0004] 2. The oil tank and the oil pump motor are moved during operation, which requires more space for placement. When the oil tank is moved quickly, the shaking caused by it can easily cause oil to overflow from the tank, resulting in oil pollution.

[0005] 3. Since hydraulic clamps need to clamp different workpieces, which have different thicknesses, softness and hardness, how to avoid excessive clamping of the workpieces and causing surface damage is a difficult problem that needs to be solved urgently. Summary of the invention

[0006] In order to solve the above technical problems, the inventors have obtained the technical solution of the present invention through practice and summary. The present invention adopts the following technical solution:

[0007] A hydraulic system for a movable hydraulic clamp that works continuously comprises an oil supply part and a clamping control part. The oil supply part provides oil for the clamping control part.

[0008] The oil supply part and the clamping control part can be selectively separated;

[0009] The clamping control part includes a clamp oil cylinder, a one-way valve, an accumulator, and an oil receiving tank;

[0010] The one-way valve and the clamp oil cylinder are connected through oil circuit 2, and a three-position four-way reversing valve and an oil cylinder reversing valve are installed on the oil circuit 2;

[0011] The one-way valve and the accumulator are connected to each other via an oil circuit;

[0012] The one-way valve and the oil receiving tank are connected via an oil circuit 4, and a liquid flow valve is installed on the oil circuit 4;

[0013] The oil receiving box and the one-way valve are connected to the oil supply part through their own oil circuits.

[0014] In the scheme, a one-way pressure reducing valve is installed on the oil circuit three to adjust the maximum pressure of the accumulator.

[0015] In the scheme, the oil circuit 2 is connected to a pressure relay via branch 1. When the pressure of the hydraulic system rises to a set value, the pressure relay feeds back a signal to the electrical system.

[0016] In the scheme, the one-way valve and the oil receiving tank are connected via an oil circuit five, and an oil drain valve one is installed on the oil circuit five.

[0017] In the scheme, the oil supply part includes an oil pump assembly and an oil tank;

[0018] The oil pump assembly and the oil tank are connected via an oil line 1;

[0019] The oil pump assembly and the one-way valve are connected via a quick-connect high-pressure oil pipe;

[0020] The oil connection box and the oil tank are connected via a second quick-connect high-pressure oil pipe.

[0021] In the scheme, an oil drain valve 2 is installed at the oil outlet of the oil receiving tank.

[0022] In the scheme, YV3 of the oil cylinder reversing valve is energized, the rodless chamber and the rod chamber of the clamp oil cylinder are switched through the valve core of the oil cylinder reversing valve, and the rodless chamber and the rod chamber of the clamp oil cylinder are communicated;

[0023] YV1 of the three-position four-way reversing valve is energized, and the oil supplied from the accumulator quickly passes through the three-position four-way reversing valve and the cylinder reversing valve to the rodless chamber and rod chamber of the clamp cylinder. The piston of the clamp cylinder moves downward to lightly clamp the workpiece, and the oil in the rod chamber of the clamp cylinder returns to the rodless chamber of the clamp cylinder through the cylinder reversing valve.

[0024] The valve core of the cylinder reversing valve is reset and the hydraulic clamp re-clamps the workpiece.

[0025] A control method for a movable hydraulic clamp adopts the hydraulic system, comprising the following steps:

[0026] Step 1. Preparation

[0027] Connect the oil pump assembly and the one-way valve via the quick-connect high-pressure oil pipe 1, connect the outlet of the oil tank and the oil tank via the quick-connect high-pressure oil pipe 2, and open the drain valve 2 at the outlet of the oil tank;

[0028] Step 2: Charge the accumulator

[0029] The oil discharged by the oil pump assembly is locked in the clamp control part through the one-way valve;

[0030] As the oil pump assembly continues to work, the accumulator is filled with oil, and the clamp cylinder works to clamp the workpiece. When the hydraulic system pressure rises to the set value, the pressure relay feeds back the signal to the electrical system, and the oil pump motor loses power and stops working.

[0031] Among them, the one-way pressure reducing valve protects the accumulator and adjusts the maximum pressure of the oil charged into the accumulator to prevent the air bag in the accumulator from being broken by the high pressure;

[0032] Step 3: Separate the oil supply part and the clamp control part

[0033] Close the oil drain valve 2 at the oil tank outlet, and separate the oil supply part and the clamp control part through the quick-connect high-pressure oil pipe 1 and the quick-connect high-pressure oil pipe 2;

[0034] Step 4: Clamp the workpiece

[0035] When clamping thin / soft workpieces:

[0036] YV3 of the oil cylinder reversing valve is energized, and the rodless chamber and the rod chamber of the clamp oil cylinder are switched through the valve core of the oil cylinder reversing valve, and the rodless chamber and the rod chamber of the clamp oil cylinder are connected;

[0037] YV1 of the three-position four-way reversing valve is energized, and the oil supplied from the accumulator quickly passes through the three-position four-way reversing valve and the cylinder reversing valve directly to the rodless chamber and the rod chamber of the clamp cylinder, and the piston of the clamp cylinder moves downward to lightly clamp the workpiece;

[0038] When clamping hard / hard workpieces:

[0039] YV1 of the three-position four-way reversing valve is energized separately, and the oil supplied from the accumulator quickly passes through the three-position four-way reversing valve and the cylinder reversing valve directly to the rodless chamber and the rod chamber of the clamp cylinder, and the piston of the clamp cylinder moves downward to re-clamp the workpiece;

[0040] Step 5: Unclamp

[0041] When relaxing thin / soft workpieces:

[0042] YV2 of the three-position four-way reversing valve is energized separately, and the oil supplied by the accumulator quickly passes through the three-position four-way reversing valve and the cylinder reversing valve directly to the rod chamber of the clamp cylinder, and the piston of the clamp cylinder moves upward to release the workpiece. Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. Since the clamp is a movable tool for clamping workpieces, and the connected oil supply part (oil tank and oil pump motor) is relatively large, it is difficult to arrange the position of the hydraulic station in some smaller spaces. Two quick-connect high-pressure oil pipes are set in the hydraulic system to facilitate the quick connection of the oil tank and the clamping control part. The hydraulic system after being filled with oil can reduce the space of the moving parts of the clamping part and enable the clamp cylinder to work normally.

[0044] 2. Since the cylinder diameter and stroke of the clamping cylinder are relatively small, the amount of pressurized oil required for each clamping is not much, and the accumulator can store multiple times the oil required for the clamping cylinder at one time (which can increase the effective volume of the accumulator, increase the storage oil volume, and increase the number of clamp working times). When the power is off or the motor cannot work due to other reasons, the manual operating lever can be used to utilize the high-pressure oil output in the accumulator to supply the clamping cylinder with the clamping and releasing actions.

[0045] 3. Since the hydraulic clamp is a movable tool for clamping workpieces, and the connected oil tank and oil pump motor are relatively large, it is difficult to arrange the position of the hydraulic station in some small spaces. A high-pressure oil pipe is set in the hydraulic system to facilitate the quick connection of the oil pipe to disassemble and assemble the oil tank and the valve group. After the hydraulic system is filled with oil, the space of the moving parts of the clamping part can be reduced, and the clamping cylinder can work normally. The oil tank and the oil pump motor are connected to the one-way valve separately with a quick connection oil pipe, and another oil pipe is connected to the drain valve on the oil tank and the return oil pipe on the oil tank.

[0046] 4. As workpieces vary in hardness, thickness and softness, some thin and soft workpieces require no indentation on the surface. Therefore, the traditional hydraulic system cannot complete the light or heavy clamping action. Once the clamping force exceeds the range, indentations will inevitably be formed on the workpiece surface. The use of this system can effectively solve the problem of light or heavy clamping and make targeted adjustments for different workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the overall structure of the system of the present invention;

[0048] Figure 2 This is a side view of the existing oil circuit.

[0049] In the figure: 1. Oil tank; 2. Liquid level gauge; 3. Air filter; 4. Oil filter; 5. Oil pump; 6. Electric motor; 7. Three-position four-way reversing valve; 8. Clamp cylinder; 9. Check valve; 10. Pressure relay; 11. Accumulator; 12. Liquid flow valve; 13. Oil drain valve 1; 14. Oil tank connection; 15. Hand lever; 16. Workpiece; 17. Hydraulic clamp; 18. Quick-connect high-pressure oil pipe 1; 19. Check valve; 20. Cylinder reversing valve; 21. Quick-connect high-pressure oil pipe 2; 22. Oil drain valve 2. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0051] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0052] Example 1

[0053] A hydraulic system for a movable hydraulic clamp that works continuously comprises an oil supply part and a clamping control part. The oil supply part provides oil for the clamping control part.

[0054] The oil supply part and the clamping control part can be selectively separated;

[0055] The clamping control part includes a clamp cylinder 18, a one-way valve 9, an accumulator 11, and an oil receiving tank 14;

[0056] The one-way valve 9 and the clamp oil cylinder 18 are connected through an oil circuit 2, and a three-position four-way reversing valve 7 and an oil cylinder reversing valve 20 are installed on the oil circuit 2;

[0057] The one-way valve 9 and the accumulator 11 are connected to each other via an oil circuit;

[0058] The one-way valve 9 and the oil receiving tank 14 are connected via an oil circuit 4, and a liquid flow valve is installed on the oil circuit 4;

[0059] The oil receiving box 14 and the one-way valve 9 are connected to the oil supply part through their own oil circuits.

[0060] Wherein, a one-way pressure reducing valve 19 is installed on the oil circuit 3 to adjust the maximum pressure of the accumulator 11.

[0061] The oil circuit 2 is connected to a pressure relay 10 via branch 1. When the pressure of the hydraulic system rises to a set value, the pressure relay 10 feeds back a signal to the electrical system.

[0062] The one-way valve 9 and the oil receiving box 14 are connected via an oil circuit 5, and an oil drain valve 13 is installed on the oil circuit 5.

[0063] The oil supply part includes an oil pump assembly and an oil tank 1, and the oil pump assembly includes an oil pump 5 and an electric motor 6. The oil tank 1 is provided with a liquid level meter 2 and an air filter 3.

[0064] The oil pump assembly and the oil tank 1 are connected via an oil circuit 1, and an oil filter 4 is installed on the oil circuit 1.

[0065] The oil pump assembly and the one-way valve 9 are connected via a quick-connect high-pressure oil pipe 18;

[0066] The oil receiving box 14 and the oil tank 1 are connected via a quick-connect high-pressure oil pipe 21 .

[0067] Wherein, an oil drain valve 22 is installed at the oil outlet of the oil receiving box 14 .

[0068] When YV3 of the oil cylinder reversing valve 20 is energized, the rodless chamber and the rod chamber of the clamp oil cylinder 18 are switched through the valve core of the oil cylinder reversing valve 20, and the rodless chamber and the rod chamber of the clamp oil cylinder 18 are communicated;

[0069] YV1 of the three-position four-way reversing valve 7 is energized, and the oil supplied from the accumulator 11 is quickly passed through the three-position four-way reversing valve 7 and the cylinder reversing valve 20 to the rodless chamber and the rod chamber of the clamp cylinder 18, and the piston of the clamp cylinder 18 moves downward to lightly clamp the workpiece, and the oil in the rod chamber of the clamp cylinder 18 returns to the rodless chamber of the clamp cylinder 18 through the cylinder reversing valve 20;

[0070] The valve core of the oil cylinder reversing valve 20 is reset, and the hydraulic clamp re-clamps the workpiece.

[0071] A control method for a movable hydraulic clamp adopts the hydraulic system, and includes the following steps:

[0072] Step 1. Preparation

[0073] The oil pump assembly is connected to the one-way valve 9 via the quick-connect high-pressure oil pipe 18, the outlet of the oil tank 14 is connected to the oil tank 1 via the quick-connect high-pressure oil pipe 21, and the oil drain valve 22 at the outlet of the oil tank 14 is opened;

[0074] Step 2: Charging the accumulator 11

[0075] The oil discharged by the oil pump assembly is locked in the clamp control part through the one-way valve 9;

[0076] As the oil pump assembly continues to work, the accumulator 11 is filled with oil, and the clamp cylinder 18 works to clamp the workpiece. When the hydraulic system pressure rises to the set value, the pressure relay 10 feeds back a signal to the electrical system, and the oil pump motor loses power and stops working.

[0077] Among them, the one-way pressure reducing valve 19 protects the accumulator 11 and adjusts the maximum pressure of the oil filled in the accumulator 11 to prevent the air bag in the accumulator 11 from being broken by the high pressure;

[0078] Step 3: Separate the oil supply part and the clamp control part

[0079] Close the oil drain valve 22 at the outlet of the oil tank 14, and separate the oil supply part and the clamp control part through the quick-connect high-pressure oil pipe 18 and the quick-connect high-pressure oil pipe 21;

[0080] Step 4: Clamp the workpiece

[0081] When clamping thin / soft workpieces:

[0082] YV3 of the oil cylinder reversing valve 20 is energized, and the rodless chamber and the rod chamber of the clamp oil cylinder 18 are switched through the valve core of the oil cylinder reversing valve 20, and the rodless chamber and the rod chamber of the clamp oil cylinder 18 are communicated;

[0083] YV1 of the three-position four-way reversing valve 7 is energized, and the oil supplied from the accumulator 11 quickly passes through the three-position four-way reversing valve 7 and the cylinder reversing valve 20 directly to the rodless chamber and the rod chamber of the clamp cylinder 18, and the piston of the clamp cylinder 18 moves downward to lightly clamp the workpiece;

[0084] When clamping hard / hard workpieces:

[0085] YV1 of the three-position four-way reversing valve 7 is energized separately, and the oil supplied from the accumulator 11 quickly passes through the three-position four-way reversing valve 7 and the cylinder reversing valve 20 directly to the rodless chamber and the rod chamber of the clamp cylinder 18, and the piston of the clamp cylinder 18 moves downward to re-clamp the workpiece;

[0086] Step 5: Unclamp

[0087] When relaxing thin / soft workpieces:

[0088] YV2 of the three-position four-way reversing valve 7 is energized separately, and the oil supplied from the accumulator 11 quickly passes through the three-position four-way reversing valve 7 and the cylinder reversing valve 20 directly to the rod chamber of the clamp cylinder 18, and the piston of the clamp cylinder 18 moves upward to release the workpiece.

[0089] Function comparison description:

[0090]

[0091] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. The replacement may be a replacement of a part of the structure, device, method step, or a complete technical solution. Any equivalent replacement or change according to the technical solution and the inventive concept of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A hydraulic system for a movable hydraulic clamp that works continuously, comprising an oil supply part and a clamping control part, wherein the oil supply part provides oil to the clamping control part, and is characterized in that: The oil supply part and the clamping control part can be selectively separated; The clamping control part comprises a clamping cylinder (18), a one-way valve (9), an accumulator (11), and an oil receiving tank (14); The one-way valve (9) and the clamp oil cylinder (18) are connected via a second oil circuit, and a three-position four-way reversing valve (7) and an oil cylinder reversing valve (20) are installed on the second oil circuit; The one-way valve (9) and the accumulator (11) are connected to each other via an oil circuit; The one-way valve (9) and the oil receiving box (14) are connected via an oil circuit 4, and a liquid flow valve is installed on the oil circuit 4; The oil receiving box (14) and the one-way valve (9) are connected to the oil supply part via their own oil circuits.

2. A hydraulic system for a movable hydraulic clamp that works continuously according to claim 1, characterized in that: A one-way pressure reducing valve (19) is installed on the oil circuit 3 to adjust the maximum pressure of the accumulator (11).

3. A movable and continuously working hydraulic system according to claim 1, characterized in that: The oil circuit 2 is connected to a pressure relay (10) via branch circuit 1. When the pressure of the hydraulic system rises to a set value, the pressure relay (10) feeds back a signal to the electrical system.

4. A hydraulic system for continuously operating movable hydraulic clamps according to claim 1, characterized in that: The one-way valve (9) and the oil receiving box (14) are connected via an oil circuit five, and an oil drain valve one (13) is installed on the oil circuit five.

5. A hydraulic system for continuously operating movable hydraulic clamps according to claim 1, characterized in that: The oil supply part comprises an oil pump assembly and an oil tank (1); The oil pump assembly and the oil tank (1) are connected via an oil circuit 1; The oil pump assembly and the one-way valve (9) are connected via a quick-connect high-pressure oil pipe (18); The oil receiving box (14) and the oil tank (1) are connected via a second quick-connect high-pressure oil pipe (21).

6. A hydraulic system for continuously operating movable hydraulic clamps according to claim 5, characterized in that: An oil drain valve 2 (22) is installed at the oil outlet of the oil receiving box (14).

7. A hydraulic system for continuously operating a movable hydraulic clamp according to any one of claims 1 to 6, characterized in that: YV3 of the oil cylinder reversing valve (20) is energized, and the rodless chamber and the rod chamber of the clamp oil cylinder (18) are switched through the valve core of the oil cylinder reversing valve (20), so that the rodless chamber and the rod chamber of the clamp oil cylinder (18) are communicated; YV1 of the three-position four-way reversing valve (7) is energized, and the oil supplied from the accumulator (11) quickly passes through the three-position four-way reversing valve (7) and the cylinder reversing valve (20) to the rodless chamber and the rod chamber of the clamp cylinder (18), and the piston of the clamp cylinder (18) moves downward to lightly clamp the workpiece, and the oil in the rod chamber of the clamp cylinder (18) returns to the rodless chamber of the clamp cylinder (18) through the cylinder reversing valve (20); The valve core of the oil cylinder reversing valve (20) is reset, and the hydraulic clamp re-clamps the workpiece.

8. A control method for a movable hydraulic clamp, using the hydraulic system according to claims 1 to 7, characterized in that: These include: Step 1. Preparation The oil pump assembly is connected to the one-way valve (9) via a quick-connect high-pressure oil pipe (18), the outlet of the oil connection box (14) is connected to the oil tank (1) via a quick-connect high-pressure oil pipe (21), and the oil drain valve (22) at the outlet of the oil connection box (14) is opened; Step 2: Charging the accumulator (11) The oil discharged by the oil pump assembly is locked in the clamp control part through the one-way valve (9); As the oil pump assembly continues to work, the accumulator (11) is filled with oil, and the clamp cylinder (18) works to clamp the workpiece. When the pressure of the hydraulic system rises to a set value, the pressure relay (10) feeds back a signal to the electrical system, and the oil pump motor loses power and stops working. The one-way pressure reducing valve (19) protects the accumulator (11) and adjusts the maximum pressure of the oil filled in the accumulator (11) to prevent the air bag in the accumulator (11) from being broken by the high pressure. Step 3: Separate the oil supply part and the clamp control part Close the oil drain valve 2 (22) at the outlet of the oil tank (14), and separate the oil supply part and the clamp control part through the quick-connect high-pressure oil pipe 1 (18) and the quick-connect high-pressure oil pipe 2 (21); Step 4: Clamp the workpiece When clamping thin / soft workpieces: YV3 of the oil cylinder reversing valve (20) is energized, the rodless chamber and the rod chamber of the clamp oil cylinder (18) are switched through the valve core of the oil cylinder reversing valve (20), and the rodless chamber and the rod chamber of the clamp oil cylinder (18) are communicated; YV1 of the three-position four-way reversing valve (7) is energized, and the oil supplied from the accumulator (11) quickly passes through the three-position four-way reversing valve (7) and the cylinder reversing valve (20) to the rodless chamber and the rod chamber of the clamp cylinder (18), and the piston of the clamp cylinder (18) moves downward to lightly clamp the workpiece; When clamping hard / hard workpieces: YV1 of the three-position four-way reversing valve (7) is energized separately, and the oil supplied from the accumulator (11) quickly passes through the three-position four-way reversing valve (7) and the cylinder reversing valve (20) to the rodless chamber and the rod chamber of the clamp cylinder (18), and the piston of the clamp cylinder (18) moves downward to re-clamp the workpiece; Step 5: Unclamp When relaxing thin / soft workpieces: YV2 of the three-position four-way reversing valve (7) is energized separately, and the oil supplied from the accumulator (11) quickly passes through the three-position four-way reversing valve (7) and the cylinder reversing valve (20) directly to the rod chamber of the clamp cylinder (18), and the piston of the clamp cylinder (18) moves upward to release the workpiece.

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