Explosion-proof valve for oil cylinder, hydraulic system and excavator
By using an explosion-proof valve in the hydraulic system, short-circuit flow of the regenerated oil in the cylinder is achieved, solving the problems of long return stroke and large flow and pressure loss of the regenerated oil, and improving the response speed of the regeneration function.
Patent Information
- Application Number
- CN202520035900.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-08
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2035-01-08
AI Technical Summary
In hydraulic systems, the regenerated oil in the cylinder has a long return stroke, large flow and pressure losses, and a slow response of the regeneration function.
An explosion-proof valve for hydraulic cylinders is adopted, including a lock-up valve, a first check valve, a second check valve, and a third check valve. By short-circuiting the oil flow path, the oil flow is prevented from flowing through the main control valve, thereby achieving a rapid response of the regeneration function.
It reduces flow pressure loss and improves the response speed of the regeneration function.
Smart Images
Figure CN223549532U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of hydraulic technology, and more specifically, to an explosion-proof valve for a hydraulic cylinder, a hydraulic system, and an excavator. Background Technology
[0002] In the field of construction machinery, most hydraulic cylinders are double-acting cylinders, meaning that both the large chamber (rodless chamber) and the small chamber (rodless chamber) of the cylinder can be filled with hydraulic oil. The hydraulic oil pushes the piston and causes the piston rod to extend and retract. When oil enters the large chamber of the cylinder, oil exits from the small chamber, and vice versa.
[0003] Some hydraulic systems are equipped with an oil regeneration function. When the cylinder extends, the oil in the smaller cylinder chamber enters the larger cylinder chamber via the regeneration oil passage in the main control valve; conversely, when the cylinder retracts, the oil in the larger cylinder chamber enters the smaller cylinder chamber via the regeneration oil passage in the main control valve. In hydraulic systems with this function, the oil entering the larger or smaller cylinder chambers includes not only pressurized oil from the hydraulic pump but also oil discharged from either chamber, thus increasing the flow rate and enabling rapid cylinder extension and retraction.
[0004] In existing hydraulic cylinders, the regeneration oil circuits all pass through the control main valve. However, in construction machinery, such as excavators, the control main valve is installed on the slewing platform, while the hydraulic cylinders, such as the boom cylinder and bucket cylinder, are located on the working device, which is far from the control main valve. The oil in the large or small chamber of the hydraulic cylinder has to flow along the pipeline to reach the small or large chamber. The oil has to travel a long path, resulting in high oil flow resistance, which causes large flow and pressure losses and slow regeneration response. Utility Model Content
[0005] The technical problem to be solved by this utility model is that the regenerated oil in the hydraulic cylinder has a long return stroke, large flow and pressure loss, and slow regeneration function response. The present invention provides an explosion-proof valve for hydraulic cylinders, a hydraulic system, and an excavator.
[0006] The technical solution of this utility model to achieve its purpose is: an explosion-proof valve for hydraulic cylinders, including a locking valve, a first check valve, and having a main valve connection port, a hydraulic cylinder connection port, and a pilot control port connected to the hydraulic control end of the locking valve; the oil inlet and oil outlet of the first check valve are connected to the main valve connection port and the hydraulic cylinder connection port respectively; the oil inlet of the locking valve is connected to the hydraulic cylinder connection port; it also includes a second check valve and a third check valve, and has a regeneration oil outlet;
[0007] The oil inlet of the second check valve and the oil inlet of the third check valve are both connected to the oil outlet of the lock valve. The oil outlet of the second check valve is connected to the main valve connection port. The oil outlet of the third check valve is connected to the regeneration oil outlet.
[0008] In the explosion-proof valve for hydraulic cylinders of this invention, the opening pressure of the second check valve is greater than the opening pressure of the third check valve.
[0009] The explosion-proof valve for hydraulic cylinders of this utility model further includes a hydraulically controlled check valve and a first damping orifice; the hydraulically controlled end of the hydraulically controlled check valve is connected to the hydraulically controlled end of the locking valve, the spring chamber of the locking valve and the reverse-flow oil inlet of the hydraulically controlled check valve are both connected to the oil inlet of the locking valve through the first damping orifice, and the reverse-flow oil outlet of the hydraulically controlled check valve is connected to the internal leakage oil passage.
[0010] The explosion-proof valve for hydraulic cylinders of this utility model also includes a second damping orifice, the two ends of which are respectively connected to the pilot control port and the internal leakage oil passage.
[0011] The explosion-proof valve for hydraulic cylinders of this utility model also includes an overflow valve, the oil inlet of which is connected to the hydraulic cylinder connection port, and the oil outlet of which is connected to the oil outlet of the locking valve. Furthermore, the spring chamber of the overflow valve is connected to the internal drain passage.
[0012] The technical solution of this utility model to achieve its purpose is as follows: a hydraulic system, including a hydraulic pump, a control main valve connected to the hydraulic pump, and a hydraulic cylinder, further including the aforementioned explosion-proof valve, which is installed on the cylinder barrel of the hydraulic cylinder; the first chamber of the hydraulic cylinder is connected to the first working port of the control main valve through a hydraulic pipeline, the second chamber is connected to the cylinder connection port of the explosion-proof valve, the main valve connection port of the explosion-proof valve is connected to the second working port of the control main valve through a hydraulic pipeline, and the regeneration outlet is connected to the first chamber of the cylinder through a pipeline; the pilot control port of the explosion-proof valve is connected to the cylinder action signal output port of the control main valve through a pipeline. Further, the first chamber of the hydraulic cylinder is a rodless chamber, and the second chamber is a rod-type chamber.
[0013] The technical solution of this utility model to achieve its purpose is: an excavator having the aforementioned hydraulic system. Further, the hydraulic cylinder is one of the boom cylinder, stick cylinder, and bucket cylinder in the excavator's working device.
[0014] Compared with the prior art, in this invention, when the hydraulic cylinder is extended or shortened due to a load acting on the piston rod, a portion of the pressurized oil discharged from the hydraulic cylinder flows directly to the hydraulic cylinder's inlet chamber through an explosion-proof valve and pipeline, achieving a regeneration function. This portion of the regenerated oil flows through a short path, bypassing the main control valve, resulting in minimal flow and pressure loss and a fast regeneration response. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the explosion-proof valve of this utility model.
[0016] Figure 2 This is a schematic diagram of the hydraulic system of this utility model.
[0017] Figure 3 This is the principle of the hydraulic system of this utility model. Figure 2 .
[0018] Component names and serial numbers in the diagram:
[0019] Explosion-proof valve 1, hydraulic pump 2, main control valve 3, hydraulic cylinder 4.
[0020] Lock-up valve 11, first check valve 12, second check valve 13, third check valve 14, hydraulic check valve 15, first damping orifice 16, internal drain passage 17, overflow valve 18, second damping orifice 19. Detailed Implementation
[0021] The specific implementation plan is described below with reference to the attached diagram.
[0022] like Figure 1 As shown, the explosion-proof valve 1 for the hydraulic cylinder includes a lock-up valve 11 and a first check valve 12, and has a main valve connection port (port A), a hydraulic cylinder connection port (port C), and a pilot control port (port Pp) connected to the hydraulic control end of the lock-up valve 11; the oil inlet and oil outlet of the first check valve 12 are connected to the main valve connection port (port A) and the hydraulic cylinder connection port (port C) respectively; the oil inlet of the lock-up valve 11 is connected to the hydraulic cylinder connection port (port C); in addition, the explosion-proof valve 1 also includes a second check valve 13 and a third check valve 14, and has a regeneration oil outlet port (port R).
[0023] The oil inlet of the second check valve 13 and the oil inlet of the third check valve 14 are both connected to the oil outlet of the lock valve 11. The oil outlet of the second check valve 13 is connected to the main valve connection port (port A); the oil outlet of the third check valve 14 is connected to the regeneration oil outlet (port R).
[0024] In this embodiment, the cylinder connection port (C port) is used to connect to one oil chamber of the hydraulic cylinder, such as the small chamber (i.e., the rod chamber) of the hydraulic cylinder. The main valve connection port (A port) is connected to the control main valve. The regeneration outlet port (R port) is connected to another oil chamber of the hydraulic cylinder, such as the large chamber (i.e., the rodless chamber) of the hydraulic cylinder. The explosion-proof valve 11 is usually installed on the cylinder barrel of the hydraulic cylinder. Therefore, the pipeline path connecting the regeneration outlet port (R port) to the chamber of the hydraulic cylinder is relatively short.
[0025] In this embodiment, if the lock-up valve 11 is open, the hydraulic oil discharged from the hydraulic cylinder flows out through the lock-up valve 11 and is divided into two paths. One path flows through the second check valve 13 from the main valve connection port (port A) to the control main valve, and the other path flows through the third check valve 14 and the regeneration outlet port (port R) to the oil inlet chamber of the hydraulic cylinder, realizing the hydraulic oil regeneration function when the hydraulic cylinder is actuated. This part of the regenerated oil flows through a short oil path and does not pass through the control main valve, resulting in small flow and pressure loss and fast regeneration response.
[0026] Optionally, the opening pressure of the second check valve 13 is greater than the opening pressure of the third check valve 14. After the oil flows out of the lock-up valve 11, it preferentially flows to the oil passage with lower hydraulic resistance. The opening pressure of the third check valve 14 is less than the opening pressure of the second check valve 13, and the hydraulic resistance of the third check valve 14 is lower. Therefore, the oil preferentially flows to the third check valve 14, that is, it preferentially responds to the regeneration function.
[0027] Optionally, the explosion-proof valve 11 further includes a hydraulically controlled check valve 15 and a first damping orifice 16; the hydraulically controlled end of the hydraulically controlled check valve 15 is connected to the hydraulically controlled end of the lock-up valve 11, the spring chamber of the lock-up valve 11 and the reverse-flow oil inlet of the hydraulically controlled check valve 15 are both connected to the oil inlet of the lock-up valve 11 through the first damping orifice 16, and the reverse-flow oil outlet of the hydraulically controlled check valve 15 is connected to the internal drain passage 17.
[0028] When pressurized oil is input to the pilot control port (Pp port), the pressure acts on the hydraulic control end of the lock-up valve 11 and also on the hydraulic control end of the hydraulic control check valve 15, causing the hydraulic control check valve 15 to be reversed. The oil in the spring chamber of the lock-up valve 11 flows to the internal drain passage 17 through the hydraulic control check valve 15, and the lock-up valve 11 changes direction from the left position to the right position, thus opening the lock-up valve 11.
[0029] When there is no pressure oil input at the pilot control port (Pp port), the hydraulic control end of the lock-up valve 11 has no hydraulic oil action, and at the same time, the hydraulic control end of the hydraulic control check valve 15 also does not have opening pressure, causing the hydraulic control check valve 15 to reverse and shut off. The pressure oil from the cylinder interface (C port) enters the spring chamber of the lock-up valve 11 through the first damping hole 16, builds pressure in the spring chamber of the lock-up valve 11, and causes the lock-up valve 11 to switch from the right position to the left position, and the lock-up valve closes.
[0030] Optionally, the explosion-proof valve 1 also includes a second damping orifice 19, the two ends of which are connected to the pilot control port (Pp port) and the internal drain passage 17, respectively. When there is no pressure oil input to the pilot control port (Pp port) and the lock-up valve reverses, the volume of the hydraulic control end of the lock-up valve 11 decreases, and hydraulic oil is discharged. The oil in the pipeline and chamber connected to the hydraulic control end of the lock-up valve 11D can flow to the internal drain passage 17 through the second damping orifice 19, so that the hydraulic control end of the lock-up valve 11 can quickly drain oil, and the lock-up valve 11 quickly reverses from the right position to the left position.
[0031] Optionally, the explosion-proof valve 1 further includes a relief valve 18, the oil inlet of which is connected to the oil cylinder connection port (C port), and the oil outlet of which is connected to the oil outlet of the lock valve 11. Preferably, the spring chamber of the relief valve 18 is connected to the internal drain passage 17.
[0032] This embodiment also provides a hydraulic system, such as Figure 2 As shown, it includes a hydraulic pump 2, a control main valve 3 connected to the hydraulic pump 2, a hydraulic cylinder 4, and the aforementioned explosion-proof valve 1. The explosion-proof valve 1 is installed on the cylinder barrel of the hydraulic cylinder 4. The first chamber of the hydraulic cylinder 4 is connected to the first working port of the control main valve 3 via a hydraulic pipeline, and the second chamber is connected to the cylinder connection port (C port) of the explosion-proof valve 1. The main valve connection port (A port) of the explosion-proof valve 1 is connected to the second working port of the control main valve 3 via a hydraulic pipeline, and the regeneration outlet port (R port) is connected to the first chamber of the hydraulic cylinder via a pipeline. The pilot control port (Pp port) of the explosion-proof valve 1 is connected to the cylinder action signal output port of the control main valve 3 via a pipeline (connection not shown in the figure). The first chamber of the hydraulic cylinder 4 can be a rodless chamber, and the second chamber can be a rod chamber. The following explanation uses the first chamber as a rodless chamber and the second chamber as a rod chamber to illustrate its working principle.
[0033] When the hydraulic cylinder 4 retracts, the main control valve 3 is in the lower position. The pressure oil output by the hydraulic pump 2 is output through the second working port of the main control valve 3, and enters the rod chamber of the hydraulic cylinder 4 through the main valve connection port (port A) of the explosion-proof valve 1, the first check valve 12, and the cylinder connection port (port C). The oil in the rodless chamber of the hydraulic cylinder 4 is discharged under the push of the piston and flows back to the hydraulic oil tank through the main control valve 3, thus realizing the retraction of the hydraulic cylinder 3.
[0034] When the hydraulic cylinder extends, the main control valve 3 outputs pilot oil into the pilot control port (Pp port) of the explosion-proof valve 1, causing the lock-up valve 11 to open. With the main control valve 3 in the upper position, the oil output from the hydraulic pump 2 enters the rodless chamber of the hydraulic cylinder 4 through the first working port of the main control valve 3. The piston of the hydraulic cylinder 4 pushes the oil in the rod chamber to be discharged through the lock-up valve 11.
[0035] When the hydraulic cylinder 4 extends, if the load on the hydraulic cylinder 4 acts on the piston rod of the hydraulic cylinder to prevent the piston rod from extending, the pressure in the rod chamber of the hydraulic cylinder 4 is less than the pressure in the rodless chamber, and all the oil discharged from the lock valve 11 flows to the control main valve 3 through the second check valve 13.
[0036] When the hydraulic cylinder extends, if the load on the hydraulic cylinder 4 acts on the piston rod, causing the hydraulic cylinder 4 to extend, the pressure in the rod chamber of the hydraulic cylinder 4 is greater than the pressure in the rodless chamber. At this time, part of the oil discharged from the lock-up valve 11 flows to the rodless chamber of the hydraulic cylinder 4 through the third check valve 14, while the other part flows to the control main valve 3 through the second check valve 13, and then flows back to the hydraulic oil tank through the control main valve 3. The oil flowing to the rodless chamber of the hydraulic cylinder 4 through the third check valve 14 and the pipeline, together with the oil from the control main valve 3, enters the rodless chamber of the hydraulic cylinder 4, making the flow rate of oil entering the rodless chamber greater than the flow rate flowing out of the control main valve 3, thus increasing the extension speed of the hydraulic cylinder.
[0037] In this embodiment, when the oil discharged from the rod chamber of the hydraulic cylinder 4 enters the rodless chamber of the hydraulic cylinder, the oil flows through the explosion-proof valve 1 and the external pipeline without passing through the control main valve 3. The oil flow path is short, the flow and pressure loss is small, and the regeneration function responds quickly.
[0038] In other implementations, such as Figure 3 As shown, the first chamber of the hydraulic cylinder 4 can be a rod chamber, and the second chamber is a rodless chamber. That is, the cylinder interface (C port) of the explosion-proof valve 1 is connected to the rodless chamber of the hydraulic cylinder 4. Correspondingly, the rod chamber of the hydraulic cylinder is connected to the control main valve 3 through a pipeline. The regeneration oil outlet (R port) of the explosion-proof valve 1 is connected to the rod chamber of the hydraulic cylinder through a pipeline. At this time, the explosion-proof valve 1 can lock the uncontrolled retraction of the hydraulic cylinder 4. During the controlled retraction of the hydraulic cylinder 4, the oil in the rodless chamber of the hydraulic cylinder 4 flows to the rod chamber of the hydraulic cylinder 4 through the locking valve and the third check valve 14, realizing the oil regeneration function of the rodless chamber.
[0039] This embodiment also provides an excavator having the aforementioned hydraulic system, wherein the hydraulic cylinder can be one of the boom cylinder, stick cylinder, and bucket cylinder in the excavator's working device.
Claims
1. An explosion-proof valve for a hydraulic cylinder, comprising a lock-up valve and a first check valve, and having a main valve connection port, a hydraulic cylinder connection port, and a pilot control port connected to the hydraulic control end of the lock-up valve; the inlet and outlet of the first check valve are respectively connected to the main valve connection port and the hydraulic cylinder connection port; the inlet of the lock-up valve is connected to the hydraulic cylinder connection port; characterized in that, It also includes a second check valve and a third check valve, and has a regeneration oil outlet; The oil inlet of the second check valve and the oil inlet of the third check valve are both connected to the oil outlet of the lock valve. The oil outlet of the second check valve is connected to the main valve connection port. The oil outlet of the third check valve is connected to the regeneration oil outlet.
2. The explosion-proof valve for hydraulic cylinders according to claim 1, characterized in that, The opening pressure of the second check valve is greater than that of the third check valve.
3. The explosion-proof valve for hydraulic cylinders according to claim 1 or 2, characterized in that, It also includes a hydraulically controlled check valve and a first damping orifice; the hydraulically controlled end of the hydraulically controlled check valve is connected to the hydraulically controlled end of the lock-up valve, the spring chamber of the lock-up valve and the reverse-flow oil inlet of the hydraulically controlled check valve are both connected to the oil inlet of the lock-up valve through the first damping orifice, and the reverse-flow oil outlet of the hydraulically controlled check valve is connected to the internal drain passage.
4. The explosion-proof valve for hydraulic cylinders according to claim 3, characterized in that, It also includes a second damping orifice, the two ends of which are connected to the pilot control port and the internal drain passage, respectively.
5. The explosion-proof valve for hydraulic cylinders according to claim 3, characterized in that, It also includes an overflow valve, the oil inlet of which is connected to the oil cylinder connection port, and the oil outlet of which is connected to the oil outlet of the lock valve.
6. The explosion-proof valve for hydraulic cylinders according to claim 5, characterized in that, The spring chamber of the overflow valve is connected to the internal drain oil passage.
7. A hydraulic system, comprising a hydraulic pump, a control main valve connected to the hydraulic pump, and a hydraulic cylinder, characterized in that, It also includes an explosion-proof valve as described in any one of claims 1 to 6, wherein the explosion-proof valve is installed on the cylinder barrel of the hydraulic cylinder; the first chamber of the hydraulic cylinder is connected to the first working port of the control main valve via a hydraulic pipeline, the second chamber is connected to the cylinder connection port of the explosion-proof valve, the main valve connection port of the explosion-proof valve is connected to the second working port of the control main valve via a hydraulic pipeline, and the regeneration outlet is connected to the first chamber of the cylinder via a pipeline; the pilot control port of the explosion-proof valve is connected to the cylinder action signal output port of the control main valve via a pipeline.
8. The hydraulic system according to claim 7, characterized in that, The first chamber of the hydraulic cylinder is a rodless chamber, and the second chamber is a rod-type chamber.
9. An excavator, characterized in that, It has the hydraulic system described in claim 7 or 8.
10. The excavator according to claim 9, characterized in that, The hydraulic cylinder is one of the boom cylinder, stick cylinder, and bucket cylinder in the working device of an excavator.