Dual oil circuit reversing valve and hydraulic tools

Abstract

The present invention provides a dual oil circuit reversing valve and a hydraulic tool. The dual oil circuit reversing valve includes a valve seat and a valve stem. The valve seat has a mounting hole in the valve seat, and the assembly surface between the valve seat and the external oil cylinder has a valve seat oil inlet hole, a valve seat oil return hole, a rodless chamber oil hole, and a rod chamber oil inlet hole. The valve stem is rotatably arranged in the mounting hole, and the valve stem has an oil groove, a first valve stem oil hole, a second valve stem oil hole, a third valve stem oil hole, a fourth valve stem oil hole, and a fifth valve stem oil hole. A three-position state under a dual oil circuit circulation is formed between the valve stem and the valve seat. In a no-load state: the oil groove on the valve stem is connected to the valve seat oil inlet hole and the valve seat oil return hole respectively, and the oil does not enter the external oil cylinder. The valve stem is rotated to form a first oil circuit circulation connecting the valve stem and the valve seat to the external oil cylinder, and the hydraulic tool is in a working state. The valve stem is rotated to form a second oil circuit circulation connecting the valve stem and the valve seat to the external oil cylinder, and the hydraulic tool is in a reset state.

Description

Technical Field

[0001] The invention relates to the field of hydraulic technology, and in particular to a dual-oil-circuit reversing valve and a hydraulic tool. Background Art

[0002] In various rescue sites and construction projects, rescue teams or construction workers need to use electric hydraulic tools to demolish metal or non-metal structures in order to rescue victims trapped in dangerous environments or to carry out construction work; and existing emergency rescue tools are mostly electric hydraulic tools.

[0003] In existing hydraulic tools, the oil in the hydraulic pump can only enter the oil cylinder in one direction, that is, it can only drive the push shaft to move forward. The push shaft needs to be manually drained and then reset by the push shaft spring. It is very inconvenient and inefficient to use during rescue or construction. To solve this problem, some hydraulic tools that can achieve automatic oil drainage have appeared on the market. For example, an oil drain switch is added at the bottom of the push shaft. When the forward stroke of the push shaft reaches the limit position, the oil drain switch is opened, and the oil in the rodless cavity flows into the rod cavity for oil return, and the push shaft is reset under the action of the push shaft spring. This method not only has the problems of slow reset speed and low efficiency, but also has the problem of difficulty in assembling the switch. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a dual oil circuit reversing valve and a hydraulic tool.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a dual oil circuit reversing valve, which includes a valve seat and a valve stem. The valve seat has a mounting hole in the valve seat, and the assembly surface of the valve seat and the external oil cylinder has a valve seat oil inlet hole, a valve seat oil return hole, a rodless chamber oil hole and a rod chamber oil inlet hole, the valve seat oil return hole is arranged on one side of the valve seat oil inlet hole along the length direction of the mounting hole, the rodless chamber oil hole is arranged on one side of the valve seat oil inlet hole along the length direction of the mounting hole, and the rod chamber oil hole is arranged on one side of the rodless chamber oil hole. The valve stem is rotatably arranged in the mounting hole, and the valve stem is provided with an oil groove, a first valve stem oil hole, a second valve stem oil hole, a third valve stem oil hole, a fourth valve stem oil hole and a fifth valve stem oil hole. The oil groove extends along the length direction of the valve stem and its length is greater than or equal to the center distance between the valve seat oil inlet hole and the valve seat oil return hole. The first valve stem oil hole and the second valve stem oil hole, which are connected to each other, are respectively arranged on both sides of the oil groove and both are located on the same cross section of the same valve stem. The third valve stem oil hole is arranged on one side of the first valve stem oil hole along the length direction of the valve stem. The fourth valve stem oil hole is connected to the third valve stem oil hole and is relatively arranged on the other side of the oil groove. The fifth valve stem oil hole is connected to the third valve stem oil hole.

[0006] Among them, a three-position state is formed between the valve stem and the valve seat under double oil circulation:

[0007] In the no-load state: the oil groove on the valve stem is connected to the valve seat oil inlet hole and the valve seat oil return hole respectively, and the oil returns through the valve seat oil inlet hole and the oil groove and then through the valve seat oil return hole, and the oil does not enter the external oil cylinder;

[0008] The first oil circuit circulation in the working state: the valve stem is rotated so that the valve seat oil inlet hole is connected to the rodless chamber oil hole through the first valve stem oil hole and the second valve stem oil hole to realize the oil inlet of the rodless chamber; the rod chamber oil inlet hole is connected to the valve seat oil return hole through the third valve stem oil hole and the fourth valve stem oil hole to realize the oil return of the rod chamber;

[0009] The second oil circuit circulation in the reset state: the oil inlet hole of the rotating valve stem and valve seat is connected to the rod chamber oil hole through the second valve stem oil hole and the rod chamber oil inlet channel on the valve seat to realize oil inflow to the rod chamber; the rodless chamber oil hole is connected to the valve seat oil return hole through the fifth valve stem oil hole and the third valve stem oil hole.

[0010] According to an embodiment of the present invention, the rod chamber oil hole is arranged outside the mounting hole, and the rod chamber oil inlet hole is connected to the third valve stem oil hole through the rod chamber oil return passage on the valve seat.

[0011] According to one embodiment of the present invention, the rod chamber oil inlet passage on the valve seat includes a first rod chamber oil inlet section connected to the second valve stem oil hole and extending along the length direction of the valve stem, and a second rod chamber oil inlet section vertically connected to the first rod chamber oil inlet section and the rod chamber oil hole.

[0012] According to an embodiment of the present invention, the fifth valve stem oil hole and the third valve stem oil hole are connected through a valve stem oil passage extending along the length direction of the valve stem.

[0013] According to an embodiment of the present invention, the axis of the first valve stem oil hole is perpendicular to the axis of the second valve stem oil hole, and the axis of the third valve stem oil hole is perpendicular to the axis of the fourth valve stem oil hole.

[0014] According to one embodiment of the present invention, the dual oil circuit reversing valve also includes a pressure regulating valve arranged on the valve seat and connected to the oil inlet hole of the valve seat. The assembly surface of the valve seat has a valve seat oil drain hole connected to the pressure relief chamber of the pressure regulating valve. The valve seat oil drain hole is connected to the valve seat oil return hole through an arc-shaped oil groove.

[0015] According to one embodiment of the present invention, the dual oil circuit reversing valve also includes a no-load positioning member, which includes an elastic member arranged at the bottom end of the valve stem and a positioning steel ball arranged at the top end of the elastic member, and the bottom of the mounting hole has a semicircular groove matching the positioning steel ball; when the valve stem is in a no-load state, the positioning steel ball is inserted into the semicircular groove.

[0016] According to one embodiment of the present invention, a limit groove is provided on the valve stem, and the positions on both sides of the limit groove limit the rotation position of the valve stem in the working state and the reset state. The dual-oil circuit reversing valve also includes a state limit member arranged at the bottom end of the valve seat and the state limit member extends into the limit groove of the valve stem.

[0017] According to an embodiment of the present invention, the dual-oil-circuit reversing valve further includes a reversing handle disposed at the end of the valve stem for driving the valve stem to rotate to switch the working position state.

[0018] Correspondingly, the present invention also provides a hydraulic tool, which includes any of the above-mentioned dual-oil circuit reversing valves.

[0019] In summary, in the dual-oil-circuit reversing valve provided by the present invention, a valve stem that can rotate relative to the valve body is arranged in the valve seat, and five valve stem oil holes and an oil groove are arranged on the valve stem. During the rotation of the valve body, a dual oil-circuit circulation connecting the rod chamber and the rodless chamber in the external oil cylinder is formed between the valve body and the valve seat. In the working state, the oil enters the rodless chamber through the first oil-circuit circulation, pushes the push rod forward and compresses the oil in the rod chamber for oil return. In the reset state, the oil enters the rod chamber through the second oil-circuit circulation, the pressure in the rod chamber increases, pushes the push shaft backward and compresses the oil in the rodless chamber for oil return. This setting realizes the two-way circulation of the oil circuit, and the push shaft quickly retreats under the action of the second oil-circuit circulation, which greatly improves the work efficiency. Furthermore, a no-load state is formed between the valve stem and the valve seat. In this state, the oil does not enter the external oil cylinder, and the hydraulic tool does not work, which not only greatly facilitates the operation of the staff, but also improves the safety of the hydraulic tool.

[0020] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is a schematic structural diagram of a dual oil circuit reversing valve provided in one embodiment of the present invention.

[0022] Figure 2 and Figure 3 for Figure 1 Schematic diagram of the structure from another perspective.

[0023] Figure 4 Shown Figure 1 Schematic diagram of the decomposition.

[0024] Figure 4A Shown Figure 4 Schematic diagram of the structure of the middle valve stem.

[0025] FIG. 5A to FIG. 5C It is a structural schematic diagram of the dual oil circuit reversing valve in a no-load state.

[0026] Fig. 6A and Figure 6B Shown is a structural schematic diagram of the dual oil circuit reversing valve in working condition.

[0027] Figure 6C for Figure 6B Schematic cross-section of the oil inlet hole through the valve seat.

[0028] Fig.6D and Fig. 6E It is a structural schematic diagram of the oil hole in the rod chamber of the dual oil circuit reversing valve in the working state.

[0029] Fig. 6F for Figure 6B Schematic diagram of the cross-section of the oil return hole through the valve seat.

[0030] Figure 6G for Figure 6B Schematic diagram of the cross section through the fifth valve stem oil hole.

[0031] Fig. 7A Shown is a structural schematic diagram of the dual oil circuit reversing valve in the reset state.

[0032] Figure 7B for Fig. 7A Schematic cross-section of the oil inlet hole through the valve seat.

[0033] Figure 7C for Fig. 7A Schematic diagram of the structure of the oil hole in the rod cavity.

[0034] Fig.7D for Fig. 7A Schematic diagram of the cross-section of the oil return hole through the valve seat.

[0035] Fig. 7E for Fig. 7A Schematic diagram of the transverse section through the oil hole of the rodless chamber.

[0036] Figure 7F for Fig. 7A Schematic diagram of the cross section through the fifth valve stem oil hole.

[0037] Figure 7G The diagram shows the structure of the 7A through-valve seat oil inlet hole and the valve seat oil return hole. DETAILED DESCRIPTION

[0038] like Figures 1 to 4As shown, the dual oil circuit reversing valve provided in this embodiment includes a valve seat 11 and a valve stem 12. The valve seat 11 has a mounting hole 111, and the assembly surface 112 of the valve seat 11 and the external oil cylinder has a valve seat oil inlet hole 11a, a valve seat oil return hole 11b, a rodless chamber oil hole 11c, and a rod chamber oil inlet hole 11d. The valve seat oil return hole 11b is arranged on one side of the valve seat oil inlet hole 11a along the length direction of the mounting hole 111, the rodless chamber oil hole 11c is arranged on one side of the valve seat oil inlet hole 11a along a direction perpendicular to the length direction of the mounting hole, and the rod chamber oil hole 11d is arranged on one side of the rodless chamber oil hole 11c. The valve stem 12 is rotatably arranged in the mounting hole 111. The valve stem 12 is provided with an oil groove 12a, a first valve stem oil hole 12b, a second valve stem oil hole 12c, a third valve stem oil hole 12d, a fourth valve stem oil hole 12e and a fifth valve stem oil hole 12f. The oil groove 12a extends along the length direction of the valve stem 12 and its length is greater than or equal to the center distance between the valve seat oil inlet hole 11a and the valve seat oil return hole 11b. The first valve stem oil hole 12b and the second valve stem oil hole 12c, which are connected to each other, are respectively arranged on both sides of the oil groove 12a and both are located on the same cross section of the same valve stem 12. The third valve stem oil hole 12d is arranged on one side of the first valve stem oil hole 12b along the length direction of the valve stem 12. The fourth valve stem oil hole 12e is connected to the third valve stem oil hole 12c and is relatively arranged on the other side of the oil groove 12a. The fifth valve stem oil hole 12f is connected to the fourth valve stem oil hole 12e.

[0039] In this embodiment, the fifth valve stem oil hole 21f and the fourth valve stem oil hole 21d are connected through a valve stem oil passage 211d extending along the length direction of the valve stem.

[0040] In this embodiment, if Figure 6C and 6F As shown in the figure, the first valve stem oil hole 12b and the second valve stem oil hole 12c are arranged at 90 degrees, and the oil delivery directions of the two are perpendicular to each other. Similarly, the third valve stem oil hole 12d and the fourth valve stem oil hole 12e are also arranged at 90 degrees. However, the present invention does not make any limitation to this. In other embodiments, the first valve stem oil hole and the second valve stem oil hole may also be arranged at other angles, and the angle value determines the rotation angle of the valve stem relative to the valve seat when switching the working state.

[0041] In this embodiment, the valve stem 12 is provided with a limit groove 121, and the positions on both sides of the limit groove 121 limit the rotational position of the valve stem in the working state and the reset state. The dual oil circuit reversing valve also includes a state limiter 14 arranged at the bottom end of the valve seat 11, and the state limiter 14 extends into the limit groove 121 of the valve stem. The dual oil circuit reversing valve also includes a no-load positioning member 15, and the no-load positioning member 15 includes an elastic member 151 arranged at the bottom end of the valve stem 12 and a positioning steel ball 152 arranged at the top end of the elastic member 151. The bottom of the mounting hole 111 has a semicircular groove 112 matching the positioning steel ball 152. In this embodiment, the limit state member 14 is a limit screw. The dual oil circuit reversing valve also includes a reversing handle 16 arranged at the end of the valve stem 12 to drive the valve stem 12 to rotate to switch the working state.

[0042] The dual oil circuit reversing valve provided in this embodiment can realize oil circuit circulation in three working positions by rotating the valve stem 12. FIG. 5A to FIG. 7G Let me introduce it in detail.

[0043] like Figures 5A to 5C As shown, in the no-load state, the reversing handle 16 is twisted to a position perpendicular to the valve seat 11, and the positioning steel ball 152 on the no-load positioning member 15 is stuck in the semicircular groove 112 to remind the operator that the position has been aligned. In this state, the valve seat oil inlet hole 11a and the valve seat oil return hole 11b are connected to the oil groove 12a on the valve stem. The oil returns through the valve seat oil inlet hole 11a and the oil groove 21a through the valve seat oil return hole 11b. The oil does not enter the external oil cylinder, the push shaft in the oil cylinder does not move, and the hydraulic tool is in a no-load state. The setting of this state greatly facilitates user operation, especially during a short pause, the user only needs to switch the hydraulic tool to the no-load state without turning off the switch of the hydraulic tool. Furthermore, the setting of this workstation state also greatly improves the user's operation in an emergency state and greatly improves the safety of operation.

[0044] like FIG. 6A to FIG. 6G As shown, turn the reversing handle 16 counterclockwise to the bottom, the state limiter 14 presses against the limiter groove 121, and the valve stem 12 and the valve seat 11 are at 45 degrees. The dual oil circuit reversing valve is in working state by connecting to the external oil cylinder through the first oil circuit circulation. Specifically, Figure 6C As shown, in this state, the valve seat oil inlet 11a is connected to the first valve stem oil hole 21b and connected to the rodless chamber oil hole 11c through the second valve stem oil hole 21c to achieve oil inlet to the rodless chamber of the external oil cylinder. Figures 6D to 6F As shown, the rod chamber oil hole 11d is connected to the third valve stem oil hole 21d through the rod chamber oil return passage 111d and is connected to the valve seat oil return hole 11b through the fourth valve stem oil hole 21e for oil return.

[0045] Oil inlet in the first oil circuit circulation: valve seat oil inlet 11a → first valve stem oil hole 21b → second valve stem oil hole 21c → rodless chamber oil hole 11c → rodless chamber;

[0046] The return oil in the first oil circuit circulation is: rod chamber oil hole 11d → rod chamber oil return passage 111d → third valve stem oil hole 21d → fourth valve stem oil hole 21e → valve seat oil return hole 11b.

[0047] In this state, if Figure 6G As shown, the fifth valve stem oil hole 21f is blocked by the inner wall of the mounting hole 111, and is not connected to the rodless chamber oil return passage 111c.

[0048] In this embodiment, the rod chamber oil port 11d is not parallel to the rodless chamber oil port 11c and is not perpendicular to the valve seat oil return port 11b. The rod chamber oil hole 11d is connected to the valve stem 12 through the rod chamber oil return passage 111d that deviates from the center axis. This arrangement provides space for processing multiple oil holes and mounting holes 111 on the valve seat to avoid processing interference.

[0049] like FIG. 7A to FIG. 7G As shown, turn the reversing handle 16 clockwise to the bottom, the state limiter 14 presses against the limiter groove 121, the valve stem 12 and the valve seat 11 are at 45 degrees, and the oil circuit reversing valve is connected to the external oil cylinder through the second oil circuit and is in the reset state. Figure 7B As shown, in this state, the valve seat oil inlet hole 11a is connected to the second valve stem oil hole 21c, and then connected to the rod chamber oil hole 11d through the rod chamber oil inlet passage to achieve oil inlet to the rod chamber. Specifically, the rod chamber oil inlet passage includes a first rod chamber oil inlet section 111a connected to the other end of the second valve stem oil hole 21c and extending along the length direction of the valve stem 21, and a second rod chamber oil inlet section 112d vertically connected to the first rod chamber oil inlet section 111a and the rod chamber oil hole 11d. At the same time, the rodless chamber oil return passage 111c connected to the rodless chamber oil hole 11c is connected to the fourth valve stem oil hole 21f; the fourth valve stem oil hole 21f is connected to the valve seat oil return hole 11b through the valve stem oil passage 211d and the third valve stem oil hole 21d to achieve oil return to the rodless chamber. Likewise, to avoid oil circuit interference, the rodless chamber oil return passage 111 c is disposed at a side deviating from the central axis of the mounting hole 111 and opposite to the rod chamber oil return passage 111 d .

[0050] The oil inlet in the second oil circuit cycle: valve seat oil inlet hole 11a → second valve stem oil hole 21c → first rod chamber oil inlet section 111a → second rod chamber oil inlet section 112d → rod chamber oil hole 11b → rod chamber;

[0051] Oil return in the second oil circuit circulation: rodless chamber oil hole 11c → rodless chamber oil return passage 111c → fifth valve stem oil hole 21f → valve stem oil passage 211d → third valve stem oil hole 21d → valve seat oil return hole 11b.

[0052] In this state, if Figure 7B and 7D As shown, the first valve stem oil hole 21 b and the fourth valve stem oil hole 21 e are blocked by the inner wall of the mounting hole 111 .

[0053] Furthermore, in this embodiment, the dual oil circuit reversing valve further includes a pressure regulating valve 13 disposed on the valve seat 11 and connected to the valve seat oil inlet hole 11a, and the assembly surface of the valve seat 11 has a valve seat oil leakage hole 11e connected to the pressure relief cavity of the pressure regulating valve 13, and the valve seat oil leakage hole 11e is connected to the valve seat oil return hole 11b through the arc-shaped oil groove 11f. Figure 6C As shown, when the movement pressure of the hydraulic tool exceeds the pressure set by the pressure regulating valve 13, the oil in the tool oil chamber directly opens the top hole 13a at the spring inside the pressure regulating valve 13 through the valve seat oil inlet 11a due to the pressure relationship, and the oil flows from the pressure relief chamber 13b through the valve seat oil relief hole 11e, the arc-shaped oil groove 11f, and enters the valve seat oil return port 11b to achieve automatic pressure relief, thereby protecting the hydraulic tool.

[0054] Correspondingly, this embodiment also provides a hydraulic tool including the dual oil circuit reversing valve provided in this embodiment. Specifically, the valve seat 11 is connected to the external oil cylinder through four mounting screws 17 and each oil hole on the valve seat assembly surface 112 is provided with a sealing ring 18 for preventing oil leakage.

[0055] In summary, in the dual-oil-circuit reversing valve provided by the present invention, a valve stem that can rotate relative to the valve body is arranged in the valve seat, and five valve stem oil holes and an oil groove are arranged on the valve stem. During the rotation of the valve body, a dual oil-circuit circulation connecting the rod chamber and the rodless chamber in the external oil cylinder is formed between the valve body and the valve seat. In the working state, the oil enters the rodless chamber through the first oil-circuit circulation, pushes the push rod forward and compresses the oil in the rod chamber for oil return. In the reset state, the oil enters the rod chamber through the second oil-circuit circulation, the pressure in the rod chamber increases, pushes the push shaft backward and compresses the oil in the rodless chamber for oil return. This setting realizes the two-way circulation of the oil circuit, and the push shaft quickly retreats under the action of the second oil-circuit circulation, which greatly improves the work efficiency. Furthermore, a no-load state is formed between the valve stem and the valve seat. In this state, the oil does not enter the external oil cylinder, and the hydraulic tool does not work, which not only greatly facilitates the operation of the staff, but also improves the safety of the hydraulic tool.

[0056] Although the present invention has been disclosed as above by the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection required by the claims.

Claims

1. A dual oil circuit reversing valve, characterized in that: include: A valve seat, wherein the valve seat has a mounting hole, and the assembly surface of the valve seat and the external oil cylinder has a valve seat oil inlet hole, a valve seat oil return hole, a rodless chamber oil hole, and a rod chamber oil inlet hole. The valve seat oil return hole is arranged on one side of the valve seat oil inlet hole along the length direction of the mounting hole, the rodless chamber oil hole is arranged on one side of the valve seat oil inlet hole along a direction perpendicular to the length direction of the mounting hole, and the rod chamber oil hole is arranged on one side of the rodless chamber oil hole; A valve stem is rotatably arranged in the mounting hole, and the valve stem is provided with an oil groove, a first valve stem oil hole, a second valve stem oil hole, a third valve stem oil hole, a fourth valve stem oil hole and a fifth valve stem oil hole, the oil groove extends along the length direction of the valve stem and its length is greater than or equal to the center distance between the valve seat oil inlet hole and the valve seat oil return hole, the first valve stem oil hole and the second valve stem oil hole, which are connected to each other, are respectively arranged on both sides of the oil groove and both are located on the same cross section of the same valve stem, the third valve stem oil hole is arranged on one side of the first valve stem oil hole along the length direction of the valve stem, the fourth valve stem oil hole is connected to the third valve stem oil hole and is relatively arranged on the other side of the oil groove, and the fifth valve stem oil hole is connected to the third valve stem oil hole; Among them, a three-position state is formed between the valve stem and the valve seat under double oil circulation: In the no-load state: the oil groove on the valve stem is connected to the valve seat oil inlet hole and the valve seat oil return hole respectively, and the oil returns through the valve seat oil inlet hole and the oil groove and then through the valve seat oil return hole, and the oil does not enter the external oil cylinder; The first oil circuit circulation in the working state: the valve stem is rotated so that the valve seat oil inlet hole is connected to the rodless chamber oil hole through the first valve stem oil hole and the second valve stem oil hole to realize the oil inlet of the rodless chamber; the rod chamber oil inlet hole is connected to the valve seat oil return hole through the third valve stem oil hole and the fourth valve stem oil hole to realize the oil return of the rod chamber; The second oil circuit circulation in the reset state: the oil inlet hole of the rotating valve stem valve seat is connected to the rod chamber oil hole through the second valve stem oil hole and the rod chamber oil inlet passage on the valve seat to realize the oil inlet of the rod chamber; the rodless chamber oil hole is connected to the valve seat oil return hole through the fifth valve stem oil hole and the third valve stem oil hole; The dual-oil-circuit reversing valve also includes a pressure-regulating valve arranged on the valve seat and connected to the oil inlet hole of the valve seat. The assembly surface of the valve seat is provided with a valve seat oil drain hole connected to the pressure relief chamber of the pressure-regulating valve. The valve seat oil drain hole is connected to the valve seat oil return hole through an arc-shaped oil groove. The dual-oil-circuit reversing valve also includes a no-load positioning member, and the no-load positioning member includes an elastic member arranged at the bottom end of the valve stem and a positioning steel ball arranged at the top end of the elastic member. The bottom of the mounting hole is provided with a semicircular groove matching the positioning steel ball. When the valve stem is in a no-load state, the positioning steel ball is inserted into the semicircular groove.

2. The dual oil circuit reversing valve according to claim 1, characterized in that: The rod chamber oil hole is arranged outside the mounting hole, and the rod chamber oil inlet hole is connected to the third valve stem oil hole through the rod chamber oil return passage on the valve seat.

3. The dual oil circuit reversing valve according to claim 1, characterized in that: The rod chamber oil inlet passage on the valve seat includes a first rod chamber oil inlet section connected to the second valve stem oil hole and extending along the length direction of the valve stem, and a second rod chamber oil inlet section vertically connected to the first rod chamber oil inlet section and the rod chamber oil hole.

4. The dual oil circuit reversing valve according to claim 1, characterized in that: The fifth valve stem oil hole and the third valve stem oil hole are communicated with each other through a valve stem oil passage extending along the length direction of the valve stem.

5. The dual oil circuit reversing valve according to claim 1, characterized in that: The axis of the first valve stem oil hole is perpendicular to the axis of the second valve stem oil hole, and the axis of the third valve stem oil hole is perpendicular to the axis of the fourth valve stem oil hole.

6. The dual oil circuit reversing valve according to claim 1, characterized in that: The valve stem is provided with a limit groove, and the positions on both sides of the limit groove limit the rotational position of the valve stem in the working state and the reset state. The dual-oil circuit reversing valve also includes a state limit member arranged at the bottom end of the valve seat and the state limit member extends into the limit groove of the valve stem.

7. The dual oil circuit reversing valve according to claim 1, characterized in that: The dual-oil-circuit reversing valve also includes a reversing handle which is arranged at the end of the valve stem and drives the valve stem to rotate to switch the working position state.

8. A hydraulic tool, characterized in that: It comprises the dual oil circuit reversing valve as described in any one of claims 1 to 7.

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