Valve structure for hydraulic cylinder main push and main pull switching use

Abstract

The utility model discloses a valve structure for hydraulic cylinder main push and main pull switching uses, and hydraulic cylinder sets up the thrust chamber, the tension chamber along piston rod, and one oil inlet of thrust chamber and tension chamber constitutes the use of hydraulic cylinder with the other oil return, and the utility model discloses a cylinder body, and the cylinder body is equipped with hole one, hole two, and the hole one is equipped with the oil inlet hole that communicates with the thrust chamber, the tension chamber, the external oil tank, and the hole two is equipped with the oil return hole that communicates with the thrust chamber, the tension chamber, the external oil tank, and the utility model discloses a valve core one, valve core two, and valve core one, valve core two can interchangeable installation in hole one, hole two, make the oil inlet and return connection switching of thrust chamber, tension chamber, carry out the switching of hydraulic cylinder main push use and main pull use, thereby can through valve core one, valve core two interchange installation position in hole one, hole two, realize the conversion between the thrust cylinder of main push or the tension cylinder of main pull of hydraulic cylinder, convenient operation, especially need not adjust the installation structure of hydraulic cylinder, and the practicality is good.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder technology, and in particular to a valve structure used for switching between main push and main pull in a hydraulic cylinder. Background Technology

[0002] As a type of commonly used hydraulic cylinder, a double-acting hydraulic cylinder has chambers on both sides of the piston for inputting pressurized oil. The chamber with oil inlet in the two chambers constitutes the working chamber. If the oil entering the working chamber is output through the piston rod in a thrust mode, it is a thrust cylinder; if the oil entering the working chamber is output through the piston rod in a pull mode, it is a pull cylinder.

[0003] Depending on the application scenario, different types of double-acting hydraulic cylinders are required. For example, in scenarios such as presses and jacks, where pushing force is needed to compress or lift heavy objects, a thrust cylinder with a main pushing action should be used. In scenarios such as clamping devices and door closing devices, where pulling force is needed to achieve, maintain, return to clamping, or close the device, a pulling cylinder with a main pulling action should be used.

[0004] In existing technologies, double-acting hydraulic cylinders cannot quickly switch between the main thrust cylinder and the main pull cylinder according to the actual application scenario requirements. Some existing double-acting hydraulic cylinders can use different installation methods to switch between the pull cylinder and thrust cylinder operation modes, but they need to be adapted to different installation structures, which is relatively troublesome in actual operation. Utility Model Content

[0005] To address the aforementioned issues, this application provides a reasonably structured valve for switching between main push and main pull functions of a hydraulic cylinder. This allows the hydraulic cylinder to quickly switch between a main push thrust cylinder and a main pull pull cylinder, making operation convenient and, in particular, eliminating the need to adjust the hydraulic cylinder's mounting structure, thus offering excellent practicality.

[0006] The technical solution adopted in this utility model is as follows: A valve structure for switching between main push and main pull modes of a hydraulic cylinder is disclosed. The hydraulic cylinder has a thrust chamber and a pull chamber along the piston rod, with one of the thrust chambers receiving oil and the other receiving oil to function as the hydraulic cylinder. The hydraulic cylinder includes a cylinder body with two mounting holes. Mounting hole one has an oil inlet communicating with the thrust chamber, the pull chamber, and an external oil tank, while mounting hole two has an oil return hole communicating with the thrust chamber, the pull chamber, and the external oil tank. The cylinder also includes valve core one and valve core two, which are interchangeably mounted in mounting holes one and two, allowing the oil inlet and return connections of the thrust chamber and the pull chamber to be switched, enabling the switching between main push and main pull modes of the hydraulic cylinder.

[0007] As a further improvement to the above technical solution: The oil inlet and oil return holes include three oil holes: one oil hole connected to the thrust chamber, two oil holes connected to the external oil tank, and three oil holes connected to the tension chamber. The ends of the three oil holes converge at the corresponding fitting hole one or fitting hole two.

[0008] The first fitting hole and the second fitting hole are fitting holes with the same structure. The three oil holes structure with the oil inlet hole at the first fitting hole and the three oil holes structure with the oil return hole at the second fitting hole have the same layout relative to the cylinder block.

[0009] Oil hole 2 of the three oil holes extends inward along the axial direction of the fitting hole. Oil holes 1 and 3 are connected to the circumference of the fitting hole. The connection positions of oil holes 1 and 3 with the fitting hole are offset in the axial direction of the fitting hole.

[0010] Both valve core one and valve core two are provided with a main oil hole, which is connected to an external oil tank via oil hole two; valve core one is provided with a through hole one that is connected to the main oil hole, and through hole one is connected to oil hole one; valve core two is provided with a through hole two that is connected to the main oil hole, and through hole two is connected to oil hole three.

[0011] The valve core one and valve core two are cylindrical structures with the same axial length. The main oil hole extends axially from the inner end face of the cylindrical structure. The through hole one and through hole two are respectively opened radially on the circumferential surface of the cylindrical structure. The through hole one is arranged close to the inner end face of the cylindrical structure, and the through hole two is arranged away from the inner end face of the cylindrical structure.

[0012] A gap is formed between the outer wall of the cylindrical structure at the location of the through hole one or through hole two and the inner wall of the fitting hole; one or more through holes one and one through hole two are respectively arranged at intervals along the circumferential direction.

[0013] The cylindrical structure extends circumferentially to form a group of convex rings on the circumferential wall near the inner end face and on the circumferential wall at the axial center. The group of convex rings forms a groove, and a sealing ring is installed in the groove. The first through hole is opened between the two groups of convex rings, and the second through hole is opened outside the two groups of convex rings.

[0014] The diameter of the second oil hole is smaller than that of the fitting hole, thus forming a limiting step. The limiting step restricts the fitting depth of the first valve core and the second valve core relative to the fitting hole.

[0015] Both fitting holes one and fitting holes two are fitting holes with stepped hole structure. The outer end of valve core one or valve core two, which is accommodated in the fitting hole, is respectively press-fitted with a screw plug, and the screw plug is threaded and accommodated in the fitting hole.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This utility model can quickly switch between the main push cylinder and the main pull cylinder by interchangeably installing valve core one and valve core two in mounting hole one and mounting hole two. It is easy to operate and does not require adjustment of the hydraulic cylinder mounting structure, making it highly practical. This utility model also has the following advantages: By setting mounting holes one and two to have the same structure, and with the oil hole structure having the same layout at both mounting holes, it can be effectively adapted to valve core one and valve core two. By interchangeably installing valve core one and valve core two at mounting holes one and two, mode conversion can be achieved; effectively ensuring the installation reliability of valve core one and valve core two at the corresponding mounting holes, and facilitating actual operation.

[0017] By setting oil hole 2 in the axial direction of the mounting hole, the connection between the mounting hole and valve core 1 and valve core 2 can be effectively guaranteed; by arranging oil hole 1 and oil hole 3 in the circumferential direction of the mounting hole and at different axial positions of the mounting hole, oil hole 1 and oil hole 3 in the mounting hole can be matched with valve core 1 and valve core 2 respectively to form a connection or blockage disconnection.

[0018] When valve core one and valve core two are installed at interchangeable positions in fitting hole one and fitting hole two, one of the thrust chamber and the pull chamber can be connected to the external oil tank through the oil inlet hole of fitting hole one to form an oil inlet, and the other can be connected to the external oil tank through the oil return hole of fitting hole two to form an oil return. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the oil circuit when the present invention is used in a hydraulic cylinder.

[0020] Figure 2 This is a structural diagram of the present invention.

[0021] Figure 3 This is a schematic diagram showing a cross-section of the present invention along the mounting hole.

[0022] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0023] Figure 5 This is a schematic diagram showing a cross-section of the present invention along the mounting hole two.

[0024] Figure 6 for Figure 5 A magnified view of a section at point B.

[0025] Figure 7 This is a schematic diagram of the structure of valve core one of this utility model.

[0026] Figure 8 This is a schematic diagram of the structure of valve core two of this utility model.

[0027] Wherein: 1. Piston rod; 2. Switching point one; 3. Switching point two; 4. Cylinder body; 5. Mounting hole one; 6. Valve core one; 7. Plug; 8. Valve core two; 9. Mounting hole two; 10. Hydraulic cylinder; 11. Thrust chamber; 12. Pulling chamber; 100. Main pulling chamber; 200. Main thrust chamber; 21. Fuel inlet line one; 22. Main fuel inlet line; 23. Fuel inlet line two; 31. Return oil line one; 32. Main return oil line; 33. Return oil line two; 51. Oil inlet hole one; 52. Oil inlet hole two; 53. Oil inlet hole three; 60. Through hole one; 61. Main oil hole; 62. Raised ring; 63. Groove; 80. Two through holes; 91. Oil return hole one; 92. Oil return hole two; 93. Oil return hole three. Detailed Implementation

[0028] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0029] like Figure 1 and Figure 2 As shown in the figure, the valve structure used for switching between main push and main pull of the hydraulic cylinder in this embodiment has a thrust chamber 11 and a pull chamber 12 arranged along the piston rod 1. One of the thrust chamber 11 and the other of the pull chamber 12 is used for oil inlet and oil return. When the thrust chamber 11 is used as the working chamber, the hydraulic cylinder 10 is used for main push and constitutes a thrust cylinder. When the pull chamber 12 is used as the working chamber, the hydraulic cylinder 10 is used for main pull and constitutes a pull cylinder.

[0030] In this embodiment, the thrust chamber 11 and the pull chamber 12 are used to distinguish between the main push and main pull modes when oil is being introduced. The thrust chamber 11 and the pull chamber 12 are essentially chambers that can be used for oil introduction and are arranged along the piston rod 1.

[0031] The hydraulic cylinder 10 includes a cylinder body 4, on which are provided mounting holes 1 5 and 2 9. Mounting hole 1 5 has an oil inlet that communicates with the thrust chamber 11, the tension chamber 12, and the external oil tank. Mounting hole 2 9 has an oil return hole that communicates with the thrust chamber 11, the tension chamber 12, and the external oil tank. It also includes valve core 1 6 and valve core 2 8, which are interchangeably mounted on mounting holes 1 5 and 2 9, so that the oil inlet and return connections of the thrust chamber 11 and the tension chamber 12 can be switched, allowing the hydraulic cylinder 10 to switch between main thrust and main tension operation.

[0032] In this embodiment, by setting mounting holes 5 and 9 on the cylinder body 4, as well as corresponding oil inlet and return holes, and combining valve cores 6 and 8, the hydraulic cylinder can be quickly switched between a main push cylinder and a main pull cylinder by interchangeably installing valve cores 6 and 8 in mounting holes 5 and 9.

[0033] like Figure 3 and Figure 5 As shown, the oil inlet and oil return holes include three oil holes: one oil hole connected to the thrust chamber 11, two oil holes connected to the external oil tank, and three oil holes connected to the tension chamber 12. The ends of the three oil holes converge to the corresponding mounting hole 1 5 or mounting hole 2 9.

[0034] In this embodiment, the three oil holes, combined with the installation of valve core 6 and valve core 8, allow oil hole 2 at the oil inlet to connect with one of oil holes 1 or 3, thus connecting the thrust chamber 11 or the pull chamber 12 to the external oil tank for oil inlet. Similarly, oil hole 2 at the oil return hole connects with one of oil holes 1 or 3, thus connecting the thrust chamber 11 or the pull chamber 12 to the external oil tank for oil return. Of course, in actual use, one of the thrust chamber 11 and the pull chamber 12 is in the oil inlet position while the other is in the oil return position.

[0035] In this embodiment, oil inlet refers to the working chamber when the hydraulic cylinder is in operation. The thrust chamber 11 and the pull chamber 12 are in the working chamber when oil is inlet, while the other is in the oil return chamber, to ensure pressure balance when the hydraulic cylinder is working.

[0036] like Figure 4 and Figure 6 As shown, mounting hole 5 and mounting hole 9 are mounting holes with the same structure. The three-row oil hole structure of the oil inlet hole at mounting hole 5 and the three-row oil hole structure of the oil return hole at mounting hole 9 have the same layout relative to cylinder block 4. Thus, they can be effectively adapted to valve core 6 and valve core 8. By interchangeably installing valve core 6 and valve core 8 at mounting holes 5 and 9, mode conversion can be achieved. This effectively ensures the installation reliability of valve core 6 and valve core 8 at the corresponding mounting holes and facilitates actual operation.

[0037] Oil hole 2 of the three oil holes extends inward along the axial direction of the fitting hole. Oil holes 1 and 3 are connected to the circumference of the fitting hole. The connection positions of oil holes 1 and 3 with the fitting hole are offset in the axial direction of the fitting hole.

[0038] In this embodiment, by setting the second oil hole in the axial direction of the mounting hole, the connection between the mounting hole and valve core 6 and valve core 8 can be effectively guaranteed; by arranging the first oil hole and the third oil hole in the circumferential direction of the mounting hole and at different axial positions of the mounting hole, the first oil hole and the third oil hole can be matched with the first valve core 6 and the second valve core 8 to form a connection or blockage disconnection.

[0039] In actual operation, the opening position and opening direction of each oil hole in the three oil holes can be matched with the oil circuit in the hydraulic cylinder to make corresponding settings, as long as each oil hole can be matched and combined with the configuration of valve core 6 and valve core 8 to form the corresponding connection requirements.

[0040] In one embodiment, oil hole one is horizontally arranged and connected to one side of the fitting hole, and oil hole three is inclinedly arranged and connected to the other side of the fitting hole; the connection positions of oil hole one, oil hole three and fitting hole are offset from each other in the axial direction of the fitting hole.

[0041] exist Figure 4 In the illustrated embodiment, an oil inlet is provided at mounting hole 1 5. The three oil inlets include an oil inlet 1 51 communicating with the thrust chamber 11, an oil inlet 2 52 communicating with the external oil tank, and an oil inlet 3 53 communicating with the tension chamber 12. The oil inlet 2 52 extends inward along the axial direction of mounting hole 1 5. The oil inlet 1 51 is horizontally arranged and communicates with one side of mounting hole 1 5, and the oil inlet 3 53 is inclined and communicates with the other side of mounting hole 1 5. By installing valve core 1 6 or valve core 2 8 at mounting hole 1 5, one of the oil inlet 1 51 and oil inlet 3 53 communicates with oil inlet 2 52.

[0042] exist Figure 6 In the illustrated embodiment, an oil return hole is provided at the mounting hole 2 9. The three oil return holes include an oil return hole 1 91 communicating with the thrust chamber 11, an oil return hole 2 92 communicating with the external oil tank, and an oil return hole 3 93 communicating with the tension chamber 12. The oil return hole 2 92 extends inward along the axial direction of the mounting hole 2 9. The oil return hole 1 91 is horizontally arranged and communicates with one side of the mounting hole 2 9, and the oil return hole 3 93 is inclined and communicates with the other side of the mounting hole 2 9. By installing the valve core 1 6 or the valve core 2 8 at the mounting hole 2 9, one of the oil return holes 1 91 and 3 93 communicates with the oil return hole 2 92.

[0043] Both valve core 1 (6) and valve core 2 (8) are provided with a main oil hole 61, which is connected to the external oil tank via oil hole 2. Valve core 1 (6) is provided with a through hole 1 (60) that is connected to the main oil hole 61 and is connected to oil hole 1. Valve core 2 (8) is provided with a through hole 2 (80) that is connected to the main oil hole 61 and is connected to oil hole 3.

[0044] In actual operation, the main oil hole 61 on valve core 1 6 and valve core 2 8 can be matched with oil hole 2. When installed in fitting hole 1 5 and fitting hole 2 9, they can be connected with the corresponding main oil hole 61 and communicate with the external oil tank.

[0045] In actual operation, the through hole 60 on valve core 6 and the through hole 80 on valve core 8 can be matched with oil holes 1 and 2 to satisfy the following: When valve core 6 is installed in either mounting hole 5 or mounting hole 9, through hole 60 connects to the thrust chamber 11 via oil hole 1, while oil hole 2 is blocked and not connected; when valve core 8 is installed in either mounting hole 5 or mounting hole 9, through hole 80 connects to the tension chamber 12 via oil hole 3, while oil hole 1 is blocked and not connected. Therefore, when valve core 6 and valve core 8 are installed in interchangeable positions in mounting holes 5 and 9, one of the thrust chamber 11 and tension chamber 12 can be connected to the external oil tank via the oil inlet at mounting hole 5 to form an oil inlet, and the other can be connected to the external oil tank via the oil return at mounting hole 9 to form an oil return.

[0046] like Figure 7 and Figure 8 As shown, valve core 6 and valve core 8 are cylindrical structures with the same axial length. The main oil hole 61 extends axially from the inner end face of the cylindrical structure. Through hole 60 and through hole 80 are respectively opened radially on the circumferential surface of the cylindrical structure. Through hole 60 is close to the inner end face of the cylindrical structure, and through hole 80 is far away from the inner end face of the cylindrical structure.

[0047] In this embodiment, valve core 6 and valve core 8 adopt similar cylindrical structures. The main oil holes 61 are both opened on the axial direction of the inner end face of the cylindrical structure. Therefore, whether they are installed in mounting hole 5 or mounting hole 9, the main oil holes 61 of valve core 6 and valve core 8 can connect and correspond with the oil holes 2 extending axially on the corresponding mounting holes, and connect with the external oil tank to form corresponding oil supply or return. This effectively ensures the adaptability and interchangeability of valve core 6 and valve core 8 between the two mounting holes.

[0048] In this embodiment, by opening the through hole 60 on valve core 6 and the through hole 80 on valve core 8 at different positions, when installed in fitting hole 5 or fitting hole 9, the main oil hole 61 can be connected to oil hole 1 or oil hole 3 through through hole 60 and through hole 80 respectively.

[0049] A gap is formed between the outer wall of the cylindrical structure at the through hole 60 or through hole 80 and the inner wall of the fitting hole; one or more through holes 60 and 80 are arranged at intervals along the circumference; thereby effectively ensuring the reliability of the connection and communication between through holes 60 and 80 and the corresponding oil hole 1 or oil hole 3 in the fitting hole, ensuring the smooth flow of the oil circuit; so that the corresponding oil hole 1 or oil hole 3 can maintain smooth communication with oil hole 2 through the main oil hole 61.

[0050] A set of convex rings 62 are formed on the circumferential wall near the inner end face and the circumferential wall at the axial center of the cylindrical structure. The set of convex rings 62 forms a groove 63, and a sealing ring is installed in the groove 63. A through hole 60 is opened between the two sets of convex rings 62, and a through hole 80 is opened outside the two sets of convex rings 62.

[0051] In this embodiment, the sealing ring inside the groove 63 effectively ensures the installation reliability between the cylindrical structure and the mounting hole. Through the installation of valve core 1 6 and valve core 2 8 in the mounting hole, oil hole 2 in the oil inlet or return hole at the mounting hole is only connected to one of oil hole 1 and oil hole 2, while maintaining and ensuring that it is blocked from communicating with the other.

[0052] The diameter of the second oil hole is smaller than that of the fitting hole, forming a limiting step. The limiting step restricts the fitting depth of valve core 6 and valve core 8 relative to the fitting hole, effectively ensuring the reliability and consistency of the installation of valve core 6 and valve core 8 in the fitting hole.

[0053] Both mounting holes 5 and 9 are stepped holes. The outer ends of valve core 6 or valve core 8, which are housed in the mounting holes, are press-fitted with screw plugs 7. The screw plugs 7 are threaded and housed in the mounting holes, which effectively ensures that valve core 6 and valve core 8 are reliably and relatively fixedly installed in the mounting holes, and is easy to operate.

[0054] In actual operation, recessed holes, such as hexagonal holes, can be opened at the outer ends of valve core 6 and valve core 8 facing the screw plug 7 to facilitate tool placement and removal, making it easier to remove and place valve core 6 and valve core 8 in the mounting hole.

[0055] exist Figure 4 and Figure 7 In the embodiment shown, the valve core 6 has a cylindrical structure with a main oil hole 61 axially formed at the center of its end. The cylindrical structure and the end of the main oil hole 61 extend outward to form a group of convex rings 62, and the group of convex rings 62 form a groove 63. Multiple through holes 60 are formed on the circumferential wall of the valve core 6 between the two groups of convex rings 62. The through holes 60 are arranged radially along the valve core 6 and communicate with the main oil hole 61.

[0056] exist Figure 5and Figure 8 In the embodiment shown, valve core 2 8 has a cylindrical structure, with a main oil hole 61 axially opened at the center of its end. The cylindrical structure and the same end of the main oil hole 61 extend outward to form a group of convex rings 62, and the group of convex rings 62 form a groove 63. Multiple through holes 2 80 are opened on the circumferential wall of valve core 2 8 located outside the middle convex ring 62. The through holes 2 80 are arranged radially along valve core 2 8 and communicate with the main oil hole 61.

[0057] In one of the uses, such as Figure 1 The diagram shown illustrates the oil circuit connection for the valve structure of this embodiment, installed and used in one type of hydraulic cylinder. (In conjunction with...) Figure 2 The fitting hole 15 corresponds to Figure 1 Switching point 1, 2, and fitting hole 2, 9 correspond to Figure 1 At switching point 2, the three oil inlets at mounting hole 1, 5, serve as components of oil inlet path 1, 21, main oil inlet path 22, and oil inlet path 23 at switching point 2, respectively. Oil inlet 1, 51, is part of oil inlet path 1, 21, which connects to thrust chamber 11; oil inlet 2, 52, is part of main oil inlet path 22, which connects to external oil tank; and oil inlet 3, 53, is part of oil inlet path 2, 23, which connects to tension chamber 12. Similarly, the three oil return holes at mounting hole 2, 9, serve as components of oil return path 1, 31, main oil return path 32, and oil return path 2, 33 at switching point 2, 3, respectively. Oil return hole 1, 91, is part of oil return path 1, 31, which connects to thrust chamber 11; oil return hole 2, 92, is part of main oil return path 32, which connects to external oil tank; and oil return hole 3, 93, is part of oil return path 2, 33, which connects to tension chamber 12.

[0058] Figure 1 The hydraulic cylinder 10 in the embodiment shown is a four-chamber cylinder. The thrust chamber 11 and the tension chamber 12 are two chambers used for compensation. In addition, a main tension chamber 100 and a main thrust chamber 200 are provided. The main tension chamber 100 and the main thrust chamber 200 are connected to the oil inlet and outlet of the external oil tank or disconnected from each other via a three-position four-way valve.

[0059] by Figure 1 Taking the four-chamber cylinder shown as an example, the main tension chamber 100 and the main thrust chamber 200 serve as the main chambers when the hydraulic cylinder is working. The thrust chamber 11 serves as the thrust compensation chamber, and the tension chamber 12 serves as the tension compensation chamber. When oil enters the thrust chamber 11 or the tension chamber 12, it plays a corresponding role in compensating for the thrust and tension.

[0060] When valve core 6 is installed at switching point 2 and valve core 8 is installed at switching point 3, as follows: Figure 1The oil circuit connection shown is such that valve core 6 connects the main oil inlet 22 and the second oil inlet 23 to the tension chamber 12, and the first oil inlet 21 is disconnected. Valve core 8 connects the main return oil line 32 and the first return oil line 31 to the thrust chamber 11, and the second return oil line 33 is disconnected. Thus, oil enters the tension chamber 12 and oil returns to the thrust chamber 11. At this time, the hydraulic cylinder outputs thrust, which is the difference between the output force generated by the main thrust chamber 200 and the tension chamber 12. The hydraulic cylinder outputs tension, which is the sum of the output forces generated by the main tension chamber 100 and the tension chamber 12. The hydraulic cylinder constitutes a tension cylinder with tension compensation by the tension chamber 12 and tension as the main force.

[0061] When valve core 6 is installed at switching point 3 and valve core 8 is installed at switching point 2, valve core 6 will connect the main return oil circuit 32 and the return oil circuit 33 to the tension chamber 12, and the return oil circuit 31 will be disconnected. Valve core 8 will connect the main inlet oil circuit 22 and the inlet oil circuit 21 to the thrust chamber 11, and the inlet oil circuit 23 will be disconnected. Thus, oil enters the thrust chamber 11 and oil returns to the tension chamber 12. At this time, the hydraulic cylinder output thrust is the sum of the output forces generated by the main thrust chamber 200 and the thrust chamber 11, and the hydraulic cylinder output tension is the difference between the output forces generated by the main tension chamber 100 and the thrust chamber 11. The hydraulic cylinder is a thrust cylinder with thrust compensation by the thrust chamber 11 and thrust as the main force.

[0062] In actual operation, the valve structure used in this embodiment can also be used in other hydraulic cylinders besides the four-chamber cylinder. It can be adjusted to suit different scenarios of switching between push and pull forces by quickly exchanging the positions of valve core 6 and valve core 8.

[0063] This invention enables the hydraulic cylinder to quickly switch between a main thrust cylinder and a main pull cylinder, making operation convenient and, in particular, eliminating the need to adjust the hydraulic cylinder's mounting structure, thus demonstrating its practicality.

[0064] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0065] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.

Claims

1. A valve structure for switching between main thrust and main pull of a hydraulic cylinder, wherein the hydraulic cylinder (10) is provided with a thrust chamber (11) and a pull chamber (12) along the piston rod (1), wherein oil is introduced into one of the thrust chamber (11) and the other returns oil to the pull chamber (12), thus constituting the use of the hydraulic cylinder (10); characterized in that: The hydraulic cylinder (10) includes a cylinder body (4), which has a mounting hole 1 (5) and a mounting hole 2 (9). The mounting hole 1 (5) has an oil inlet hole that communicates with the thrust chamber (11), the pull chamber (12) and the external oil tank. The mounting hole 2 (9) has an oil return hole that communicates with the thrust chamber (11), the pull chamber (12) and the external oil tank. It also includes a valve core 1 (6) and a valve core 2 (8). The valve core 1 (6) and the valve core 2 (8) can be interchangeably installed in the mounting hole 1 (5) and the mounting hole 2 (9) so that the oil inlet and return connections of the thrust chamber (11) and the pull chamber (12) can be switched to switch the main thrust and main pull of the hydraulic cylinder (10).

2. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 1, characterized in that: The oil inlet and oil return holes include three oil holes: one oil hole connected to the thrust chamber (11), two oil holes connected to the external oil tank, and three oil holes connected to the tension chamber (12). The ends of the three oil holes converge at the corresponding fitting hole one (5) or fitting hole two (9).

3. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 2, characterized in that: The fitting hole one (5) and fitting hole two (9) are fitting holes with the same structure. The three-row oil hole structure of the oil inlet hole at fitting hole one (5) and the three-row oil hole structure of the oil return hole at fitting hole two (9) are arranged in the same way relative to the cylinder block (4).

4. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 3, characterized in that: Oil hole 2 of the three oil holes extends inward along the axial direction of the fitting hole. Oil holes 1 and 3 are connected to the circumference of the fitting hole. The connection positions of oil holes 1 and 3 with the fitting hole are offset in the axial direction of the fitting hole.

5. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in any one of claims 2-4, characterized in that: Both valve core one (6) and valve core two (8) are provided with main oil holes (61), and the main oil holes (61) are connected to the external oil tank through oil hole two; valve core one (6) is provided with a through hole one (60) that communicates with the main oil holes (61), and the through hole one (60) is connected to oil hole one; valve core two (8) is provided with a through hole two (80) that communicates with the main oil holes (61), and the through hole two (80) is connected to oil hole three.

6. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 5, characterized in that: The valve core one (6) and valve core two (8) are cylindrical structures with the same axial length. The main oil hole (61) extends axially from the inner end face of the cylindrical structure. The through hole one (60) and through hole two (80) are respectively opened radially on the circumferential surface of the cylindrical structure. The through hole one (60) is close to the inner end face of the cylindrical structure, and the through hole two (80) is far away from the inner end face of the cylindrical structure.

7. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 6, characterized in that: A gap is formed between the outer wall of the cylindrical structure at the location of the through hole one (60) or through hole two (80) and the inner wall of the fitting hole; one or more through holes one (60) and one through hole two (80) are respectively arranged at intervals along the circumferential direction.

8. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 6, characterized in that: The cylindrical structure extends circumferentially to form a group of convex rings (62) on the circumferential wall near the inner end face and the circumferential wall at the axial center, respectively. The group of convex rings (62) forms a groove (63), and a sealing ring is installed in the groove (63). The first through hole (60) is opened between the two groups of convex rings (62), and the second through hole (80) is opened outside the two groups of convex rings (62).

9. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 4, characterized in that: The diameter of the second oil hole is smaller than that of the fitting hole, thus forming a limiting step. The limiting step restricts the fitting depth of the first valve core (6) and the second valve core (8) relative to the fitting hole.

10. The valve structure for switching between main push and main pull in a hydraulic cylinder as described in claim 1 or 3, characterized in that: The first fitting hole (5) and the second fitting hole (9) are both fitting holes with stepped hole structure. The outer end of the first valve core (6) or the second valve core (8) housed in the fitting hole is respectively press-fitted with a screw plug (7). The screw plug (7) is threaded and housed in the fitting hole.

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