Machine tool vertical shaft anti-falling hydraulic system and gantry machining center

Abstract

The utility model provides a kind of machine tool vertical shaft anti-falling hydraulic system and gantry type machining center, it is related to hydraulic safety protection field, the scheme used is: including check valve and balance cylinder, the oil outlet of check valve is communicated with the rod cavity of balance cylinder, further include: oil storage unit, the oil inlet of check valve is communicated with oil storage unit;Overflow valve one, the oil inlet of overflow valve one can be communicated with balance cylinder, the oil inlet of overflow valve one is communicated with the oil storage unit;Overflow valve two, the oil inlet of overflow valve two is communicated with the oil outlet of overflow valve one, the oil outlet of overflow valve two can be communicated with external container, the opening pressure of overflow valve two is greater than the opening pressure of overflow valve one.The utility model can still support vertical shaft when hydraulic system leaks and jams, prevent vertical shaft accelerated falling and cause risk.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic safety protection, and in particular to a hydraulic system for preventing machine tool vertical axis fall and a gantry machining center. Background Technology

[0002] The main methods for balancing the vertical axis of a gantry machining center include mechanical weight balancing, hydraulic balancing cylinder balancing, and pneumatic balancing cylinder balancing. Among these, hydraulic balancing cylinder balancing, due to its high pressure and stable balancing force, is particularly suitable for balancing the vertical axis of heavy-duty gantry machining centers.

[0003] In the prior art, Chinese utility model patent with authorization announcement number CN206415964 U discloses a hydraulic gravity balance control system, including a hydraulic control circuit and a balance cylinder. The hydraulic control circuit includes an oil inlet connected to the input end of a pressure reducing valve. The output end of the pressure reducing valve is connected to the input end of a two-position three-way directional valve. The output end of the two-position three-way directional valve is connected in parallel to a pilot-operated three-way pressure reducing valve and a hydraulically controlled check valve. The output end of the hydraulically controlled check valve is connected to the balance cylinder via an accumulator. A shut-off valve is installed on the connection passage between the accumulator and the oil tank. This technical solution minimizes the fluctuation of the balance pressure in the balance cylinder during the upward and downward switching of the vertical axis, reducing the response burden on the linear drive section and thus improving machining accuracy.

[0004] When the above technical solution is adopted, when the vertical shaft moves downward, along the flow direction of the hydraulic oil, since the pressure reducing valve is located in front of the hydraulic control check valve, if the accumulator or the hydraulic control check valve and the pipeline between them leak, the system pressure will drop significantly, and the pressure reducing valve will not be able to generate back pressure. At the same time, if the accumulator or the hydraulic control check valve becomes blocked, the pressure at the end of the system will be too high, causing the pipeline to burst and the system pressure to drop suddenly. All of these will cause the hydraulic system to be unable to support the vertical shaft, causing the vertical shaft to fall rapidly, which poses a risk of injuring the workpiece and the worktable, and even injuring the nearby machine tool operator, thereby affecting production safety and production efficiency. Utility Model Content

[0005] To address the technical problem in the prior art where the hydraulic balancing system cannot support the vertical axis of the machine tool when it leaks, this utility model provides a hydraulic system for preventing the vertical axis of the machine tool from falling and a gantry machining center. This system can still support the vertical axis when the hydraulic system leaks or becomes blocked, preventing the vertical axis from accelerating downwards and causing risks.

[0006] In a first aspect, this utility model provides a hydraulic system for preventing the vertical axis of a machine tool from falling, which solves the above-mentioned technical problems. The system includes a one-way valve and a balance cylinder, wherein the oil outlet of the one-way valve is connected to the rod chamber of the balance cylinder. It also includes: an oil supply and storage unit, wherein the oil inlet of the one-way valve is connected to the oil supply and storage unit; a first relief valve, wherein the oil inlet of the first relief valve is connected to the rod chamber of the balance cylinder, and the oil inlet of the first relief valve is connected to the oil supply and storage unit; and a second relief valve, wherein the oil inlet of the second relief valve is connected to the oil outlet of the first relief valve, and the oil outlet of the second relief valve can be connected to an external container. The opening pressure of the second relief valve is greater than the opening pressure of the first relief valve.

[0007] This invention, by setting up two relief valves, can achieve the following when the vertical shaft is descending: Firstly, when a leak occurs in the pipeline, the relief valve generates back pressure to maintain the pressure in the rod chamber, preventing the vertical shaft from losing support and falling. Secondly, when the pipeline is blocked, the relief valve performs a two-stage pressure relief function to overflow, greatly reducing the pressure in the system and preventing the pipeline from bursting, thus maintaining the support for the vertical shaft. It is evident that this solution can still support the vertical shaft when the hydraulic system leaks or becomes blocked, preventing the vertical shaft from accelerating downwards and causing risks.

[0008] Furthermore, a pressure sensor is installed at the oil port of the rod chamber of the balance cylinder.

[0009] This invention, by setting a pressure sensor, can promptly monitor the oil pressure of the balance cylinder, so that a stop signal can be issued in time when the oil pressure is abnormal, thus ensuring the stable operation of the machine tool.

[0010] Furthermore, the oil outlet of the first overflow valve is provided with an oil pipe, and a ball valve is provided on the oil pipe. The oil outlet of the first overflow valve is connected to the oil supply and storage unit through the ball valve. The oil pipe is connected to the oil inlet of the one-way valve through an oil pipe. The one-way valve is connected to the oil supply and storage unit through the ball valve. The oil pipe is also connected to the oil inlet of the second overflow valve.

[0011] This invention improves the reliability of hydraulic system control by incorporating a second ball valve.

[0012] Furthermore, oil pipe one is connected to oil pipe three, and oil pipe three is equipped with ball valve two.

[0013] This invention, by setting a second ball valve, can, in conjunction with the first ball valve, depressurize the accumulator and balance cylinder for replacement.

[0014] Furthermore, a pressure gauge is installed at the oil port of the rod chamber of the balance cylinder.

[0015] By incorporating a pressure gauge, this invention can promptly detect abnormal pressure in the hydraulic system. Furthermore, in conjunction with ball valves one and two, it can check the condition of relief valve one when the machine tool is stopped, ensuring regular maintenance of the relief valve.

[0016] Furthermore, the oil supply and storage unit adopts an accumulator, the oil inlet of the one-way valve is connected to the accumulator through the ball valve, and the oil outlet of the overflow valve is connected to the accumulator through the ball valve.

[0017] This invention uses an accumulator for oil supply, eliminating the need for an oil pump, simplifying the machine tool structure, and reducing noise.

[0018] Secondly, this utility model also provides a gantry machining center, including a gantry frame, on which a vertical shaft is movably arranged in a vertical direction, and also includes the aforementioned machine tool vertical shaft anti-fall hydraulic system, wherein the vertical shaft is connected to the cylinder body of the balance cylinder, and the vertical shaft can drive the cylinder body of the balance cylinder to move.

[0019] Furthermore, it also includes a machine tool oil tank, with the oil outlet of the overflow valve two connected to the machine tool oil tank, and the oil outlet of the ball valve two connected to the machine tool oil tank.

[0020] This invention, by connecting the oil outlet of the overflow valve two to the oil tank, can further reduce the pressure of the machine tool vertical axis anti-fall hydraulic system and enhance the pressure-bearing capacity of the machine tool vertical axis anti-fall hydraulic system. At the same time, the oil outlet of the ball valve two is connected to the machine tool oil tank, which can discharge the hydraulic oil in the accumulator or balance cylinder to the machine tool oil tank, making it easier to replace parts, reducing the capacity requirements of the machine tool vertical axis anti-fall hydraulic system, and reducing the size of the parts.

[0021] Furthermore, it also includes a controller, which is electrically connected to the pressure sensor.

[0022] As can be seen from the above technical solutions, this utility model has the following advantages: This utility model provides a hydraulic system for preventing the vertical axis of a machine tool from falling and a gantry machining center. By setting up two relief valves, when the vertical axis is descending, on the one hand, when a pipeline leak occurs, the relief valve one generates back pressure to maintain the pressure in the rod chamber, preventing the vertical axis from losing support and falling. On the other hand, when the pipeline is blocked, the relief valve two performs a two-stage pressure relief function, overflowing and greatly reducing the pressure in the system, preventing pipeline rupture and maintaining the support for the vertical axis. Therefore, this solution can still support the vertical axis and prevent the vertical axis from accelerating downwards and causing risks even when the hydraulic system leaks or is blocked. The addition of a pressure sensor allows for timely monitoring of the balance. The hydraulic system is equipped with a second ball valve to improve the reliability of its control. A pressure gauge is used to detect abnormal hydraulic pressure and, in conjunction with ball valves one and two, to check the condition of relief valve one during machine shutdown, ensuring regular maintenance of the relief valve. Using an accumulator for oil supply eliminates the need for an oil pump, simplifying the machine structure and reducing noise. Connecting the outlets of relief valve two and ball valve two to an oil tank reduces costs and space requirements compared to using separate containers, and allows for the reuse of hydraulic oil. Attached Figure Description

[0023] To more clearly illustrate the technical solution of this utility model, the drawings used in the description 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.

[0024] Figure 1 This is a structural schematic diagram of one embodiment of the present utility model.

[0025] Figure 2 This is a schematic diagram of the structure of this utility model after removing the oil supply unit and the balance cylinder.

[0026] Figure 3 This is a partial structural diagram of Embodiment 2 of the present utility model.

[0027] In the diagram, 1. Accumulator; 2. Ball valve one; 3. Oil supply and storage unit; 4. Overflow valve two; 5. Ball valve two; 6. Pressure sensor; 7. Pressure gauge; 8. Check valve; 9. Balance cylinder; 10. Overflow valve one; 11. Machine tool oil tank; 12. Vertical shaft; 13. Gantry frame; 15. Oil pipe one; 16. Oil pipe two; 17. Oil pipe three. Detailed Implementation

[0028] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0029] Example 1 like Figure 1 and Figure 2 As shown in the figure, this specific embodiment provides a hydraulic system for preventing the vertical axis of a machine tool from falling, including a one-way valve 8, a balance cylinder 9, a first relief valve 10, a second relief valve 4, and an oil supply and storage unit 3. The oil inlet of the one-way valve 8 is connected to the oil supply and storage unit 3, and the oil outlet of the one-way valve 8 is connected to the rod chamber of the balance cylinder 9. The oil inlet of the first relief valve 10 is connected to the rod chamber of the balance cylinder 9, and the oil inlet of the first relief valve 10 is connected to the oil supply and storage unit 3. The oil inlet of the second relief valve 4 is connected to the oil outlet of the first relief valve 10, and the oil outlet of the second relief valve 4 can be connected to an external container. The opening pressure of the second relief valve 4 is greater than the opening pressure of the first relief valve 10.

[0030] In this embodiment, by setting relief valve 10 and relief valve 4, the pressure in the rod chamber increases when the vertical shaft 12 descends. On the one hand, when a leak occurs in the pipeline, the system pressure decreases. At this time, the state of relief valve 10 changes from open to closed, generating back pressure to maintain the pressure in the rod chamber and prevent the vertical shaft 12 from losing support and falling. On the other hand, when the pipeline is blocked, the pressure in the system surges. Relief valve 4 plays a secondary pressure relief role, overflowing and greatly reducing the pressure in the system. This prevents the pipeline from bursting under continuous high pressure, causing a sudden drop in system pressure and maintaining the support for the vertical shaft 12. It can be seen that this solution can still support the vertical shaft 12 when the hydraulic system leaks or is blocked, preventing the vertical shaft 12 from accelerating downward and causing risks.

[0031] To improve the reliability and security of this system, such as Figure 1 and Figure 2 As shown, in this embodiment, a pressure sensor 6 is provided at the oil port of the rod chamber of the balance cylinder 9. In this embodiment, the pressure sensor 6 is a pressure relay, which can send an electrical signal to the machine tool controller when the pressure is abnormal, stop the vertical shaft 12 from falling, and avoid damage to the system.

[0032] To improve the reliability and controllability of this system, such as Figure 1 and Figure 2As shown, in this embodiment, the outlet of the overflow valve 10 is provided with an oil pipe 15, and a ball valve 2 is provided on the oil pipe 15. The outlet of the overflow valve 10 is connected to the oil supply and storage unit 3 through the ball valve 2. By setting the ball valve 2, the main oil circuit of the system is provided with a switch valve. During normal operation, it allows hydraulic oil to flow from the accumulator 1 or the machine tool oil tank 11 to the balance cylinder 9 to maintain the balance pressure of the vertical shaft 12. When it is necessary to isolate the accumulator 1 and the balance cylinder 9 (such as replacing the accumulator 1 or performing maintenance), closing the ball valve 2 can cut off the oil circuit to prevent oil leakage or accidental pressure relief. In addition, the oil pipe 15 is connected to the inlet of the check valve 8 through an oil pipe 16. The check valve 8 is connected to the oil supply and storage unit 3 through the ball valve 2. The oil pipe 16 is also connected to the inlet of the overflow valve 4.

[0033] To facilitate the security detection and maintenance of this system, such as Figure 1 and Figure 2 As shown, in this embodiment, oil pipe 15 is connected to oil pipe 3 17. A ball valve 2 5 is installed on oil pipe 3 17, and ball valve 2 5 is connected to an external container. Through ball valve 2 5, the accumulator 1 or balance cylinder 9 can be connected to the external container, allowing for system depressurization and facilitating maintenance of the accumulator 1 and balance cylinder 9. Furthermore, a pressure gauge 7 is installed at the oil port of the rod chamber of the balance cylinder 9. The pressure gauge 7 allows for direct observation of the pressure at the oil port of the rod chamber of the balance cylinder 9, enabling monitoring of the system's operational status. Simultaneously, this pressure gauge 7, in conjunction with ball valves 1 2 and 2 5, allows for determination of the normal operation of the relief valve 10 when the machine tool is stopped. If leakage occurs, the pressure gauge 7 reading decreases when ball valve 1 2 is closed and ball valve 2 5 is opened, requiring disassembly, cleaning, or replacement of the relief valve 10. When the relief valve 10 is functioning normally and remains closed, the pressure gauge 7 reading remains unchanged when ball valve 1 2 is closed and ball valve 2 5 is opened.

[0034] The oil supply and storage unit 3 can be a machine tool oil tank or other dedicated oil tank, and oil is supplied by an oil pump. In this embodiment, for example... Figure 1 and Figure 2 As shown, the oil supply and storage unit 3 uses an accumulator 1. The oil inlet of the one-way valve 8 is connected to the accumulator 1 through the ball valve 2, and the oil outlet of the overflow valve 10 is connected to the accumulator 1 through the ball valve 2. Compared with using an oil tank and an oil pump for oil supply, the oil pump is eliminated, and noise reduction is achieved.

[0035] The working process of the vertical axis anti-fall hydraulic system of this machine tool is as follows: Under normal operating conditions, ball valve 12 is normally open and ball valve 25 is normally closed. When the vertical shaft 12 moves upward, during normal operation of the system, the cylinder body of the balance cylinder 9 moves upward, and the hydraulic oil enters the rod chamber of the balance cylinder 9 from the accumulator 1 through the P port and the one-way valve 8 from the S port. When the vertical axis 12 of the machine tool moves downward, the cylinder body of the balance cylinder 9 moves downward, and the pressure in the rod chamber gradually increases until the overflow valve 10 is opened, and the hydraulic oil flows back to the accumulator 1 through the S port and the overflow port of the overflow valve 10. When the vertical axis 12 of the machine tool is moving upward or stationary, if a pipeline bursts or is disconnected due to improper pipeline connection at the P port of the accumulator 1, the system pressure will be too low. The state of the relief valve 10 will change from open to closed, and the hydraulic oil will no longer flow back from the cylinder to the accumulator 1. The pressure required by the vertical axis 12 of the machine tool will be maintained in the balance cylinder 9 to prevent the vertical axis 12 from falling. At the same time, the pressure sensor 6 will detect the pressure abnormality and send a stop signal. When the vertical axis 12 of the machine tool moves downward, if there is a blockage in the pipeline from the accumulator 1 to the P port or the valve core inside the accumulator 1 is not opened, the pressure in the rod chamber will increase to the opening pressure of the relief valve 4. Then the hydraulic oil will overflow to the external container through the overflow port and T port of the relief valve 4. At the same time, the pressure sensor 6 will detect the abnormal pressure and issue a stop signal. When the vertical axis 12 of the machine tool is descending, if the overflow valve 10 fails to open due to jamming, causing the pressure in the rod chamber of the balance cylinder 9 to rise abnormally, the pressure sensor 6 will detect the abnormal pressure and stop the descent of the vertical axis 12 of the machine tool. When the machine tool is in a stopped state, periodically close ball valve 12 and open ball valve 25 while observing pressure gauge 7. If the reading on pressure gauge 7 decreases when ball valve 25 is opened, then relief valve 10 is in a normally open state. Close ball valve 25 and disassemble, clean or replace relief valve 10. When accumulator 1 needs to be replaced, ball valve 25 is opened to release pressure from accumulator 1. The hydraulic oil in accumulator 1 is discharged through ball valve 12, oil pipe 26 and ball valve 25. Under the action of relief valve 10, the main body always maintains the support of the vertical axis 12 of the machine tool. When the balance cylinder 9 needs to be replaced, close ball valve 12, open ball valve 25, and slowly reduce the opening pressure of relief valve 10. The hydraulic oil in the balance cylinder 9 will be discharged through relief valve 10 and ball valve 25, thus completing the pressure relief of the balance cylinder 9, while the pressure in the accumulator 1 remains unchanged.

[0036] Example 2 like Figure 3As shown, this embodiment also provides a gantry machining center, including a gantry frame 13. A vertical shaft 12 is movably mounted on the gantry frame 13 in the vertical direction. Specifically, the vertical shaft 12 is slidably connected to the gantry frame 13 via a guide rail. A motor and a lead screw are also mounted on the gantry frame 13. The lead screw is connected to the vertical shaft 12 and is rotatably mounted on the gantry frame 13 via a bearing seat. It also includes the machine tool vertical shaft anti-fall hydraulic system of Embodiment 1. The vertical shaft 12 is connected to the cylinder body of the balance cylinder 9 via a flange or trunnion. The vertical shaft 12 can drive the cylinder body of the balance cylinder 9 to move. It also includes a controller. The ball valve 5 controller is electrically connected to the pressure sensor 6 and the motor.

[0037] like Figure 3 As shown, in this embodiment, a machine tool oil tank 11 is also included. The oil outlet of the overflow valve 4 is connected to the machine tool oil tank 11, and the oil outlet of the ball valve 5 is connected to the machine tool oil tank 11. Compared with using an independent container, this reduces costs, reduces the space occupied by the machine tool, and realizes the recycling of hydraulic oil, saving energy.

[0038] As can be seen from the above specific embodiments, this utility model has the following beneficial effects: 1. By setting relief valve 10 and relief valve 4, when the vertical shaft 12 is descending, on the one hand, when the pipeline leaks, the back pressure generated by relief valve 10 maintains the pressure in the rod chamber, preventing the vertical shaft 12 from losing support and falling. On the other hand, when the pipeline is blocked, the relief valve 4 plays a secondary pressure relief role, overflowing and greatly reducing the pressure in the system, preventing the pipeline from bursting, and maintaining the support for the vertical shaft 12. It can be seen that this solution can still support the vertical shaft 12 when the hydraulic system leaks or is blocked, preventing the vertical shaft 12 from accelerating downward and causing risks. 2. By setting pressure sensor 6, the oil pressure of balance cylinder 9 can be monitored in a timely manner, so as to issue a stop signal in time when the oil pressure is abnormal, ensuring the stable operation of the machine tool; by setting ball valve 2 5, the reliability of the control of this hydraulic system can be improved. 3. By setting pressure gauge 7, on the one hand, abnormal pressure in this hydraulic system can be detected in time; on the other hand, it can cooperate with ball valve 2 5 and ball valve 1 2 to check whether relief valve 10 is normal when the machine tool is stopped, so as to ensure the regular maintenance of relief valve. 4. By using accumulator 1 for oil supply, there is no need to install an oil pump, which simplifies the machine tool structure and reduces noise; 5. By connecting the oil outlets of relief valve 24 and ball valve 25 to the oil tank, compared with using separate containers, the cost is reduced, the space occupied is reduced, and the hydraulic oil can be reused.

[0039] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic system for preventing vertical shaft fall in a machine tool, comprising a one-way valve (8) and a balance cylinder (9), wherein the oil outlet of the one-way valve (8) is connected to the rod chamber of the balance cylinder (9), characterized in that, Also includes: The oil supply and storage unit (3) is connected to the oil inlet of the one-way valve (8); Overflow valve one (10), the oil inlet of the overflow valve one (10) is connected to the rod chamber of the balance cylinder (9), and the oil inlet of the overflow valve one (10) is connected to the oil supply and storage unit (3); Overflow valve two (4), the oil inlet of the overflow valve two (4) is connected to the oil outlet of the overflow valve one (10), the oil outlet of the overflow valve two (4) can be connected to an external container, and the opening pressure of the overflow valve two (4) is greater than the opening pressure of the overflow valve one (10).

2. The machine tool vertical axis anti-fall hydraulic system as described in claim 1, characterized in that, A pressure sensor (6) is installed at the oil port of the rod chamber of the balance cylinder (9).

3. The machine tool vertical axis anti-fall hydraulic system as described in claim 2, characterized in that, The outlet of the overflow valve (10) is provided with an oil pipe (15), and a ball valve (2) is provided on the oil pipe (15). The outlet of the overflow valve (10) is connected to the oil supply and storage unit (3) through the ball valve (2). The oil pipe (15) is connected to the inlet of the check valve (8) through the oil pipe (2). The check valve (8) is connected to the oil supply and storage unit (3) through the ball valve (2). The oil pipe (2) is also connected to the inlet of the overflow valve (4).

4. The machine tool vertical axis anti-fall hydraulic system as described in claim 3, characterized in that, The first oil pipe (15) is connected to the third oil pipe (17), and the third oil pipe (17) is equipped with a second ball valve (5).

5. The machine tool vertical axis anti-fall hydraulic system as described in claim 4, characterized in that, A pressure gauge (7) is installed at the oil port of the rod chamber of the balance cylinder (9).

6. The machine tool vertical axis anti-fall hydraulic system as described in claim 5, characterized in that, The oil supply and storage unit (3) adopts an accumulator (1). The oil inlet of the one-way valve (8) is connected to the accumulator (1) through the ball valve (2). The oil outlet of the overflow valve (10) is connected to the accumulator (1) through the ball valve (2).

7. A gantry machining center, comprising a gantry frame (13), wherein a vertical shaft (12) is movably mounted on the gantry frame (13) in a vertical direction, characterized in that, It also includes the machine tool vertical axis anti-fall hydraulic system as described in claim 5, wherein the vertical axis (12) is connected to the cylinder body of the balance cylinder (9), and the vertical axis (12) can drive the cylinder body of the balance cylinder (9) to move.

8. The gantry machining center as described in claim 7, characterized in that, It also includes a machine tool oil tank (11), the oil outlet of the overflow valve 2 (4) is connected to the machine tool oil tank (11), and the oil outlet of the ball valve 2 (5) is connected to the machine tool oil tank (11).

9. The gantry machining center as described in claim 8, characterized in that, It also includes a controller, wherein the ball valve two (5) controller is electrically connected to the pressure sensor (6).

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