Pre-tensioned single-acting oil cylinder

Abstract

The utility model relates to single -acting oil cylinder discloses a pre -shrink type single -acting oil cylinder, include: cylinder barrel, oil cylinder stem, compression spring, pipe joint and connecting body. Hydraulic system is connected to first connecting hole through pipeline, is switched over through solenoid valve, and pipeline switches between following two states: connecting oil circuit and the oil inlet pipe of hydraulic system, connecting oil circuit and the oil return pipe of hydraulic system. When the pipeline is the oil inlet pipe of connecting oil circuit and the hydraulic system, the oil in the oil tank enters the cylinder barrel from the oil pipe, the oil circuit, and the hollow area is opposite the piston part of oil cylinder stem, makes the oil cylinder stem overcome the compression spring effect and stably extends. When the pipeline is the oil return pipe of connecting oil circuit and the hydraulic system, under the compression spring action, the oil cylinder stem retracts to the original position, and the oil in the cylinder cavity stably pushes back the oil tank from the oil circuit, the oil pipe. When the oil circuit fails, the connecting body and the pipe joint can be disassembled, and the parts are conveniently repaired and replaced.

Description

Technical Field

[0001] This utility model relates to a single-acting hydraulic cylinder, and more particularly to a pre-retracted single-acting hydraulic cylinder. Background Technology

[0002] A single-acting hydraulic cylinder is divided into two parts by the piston of the cylinder rod. One part houses the compression spring, and the other part has a connecting oil passage for hydraulic fluid to enter. Depending on the location of the compression spring, single-acting cylinders can be classified as either pre-extension or pre-retraction types. In the pre-retraction type, the compression spring is sleeved on the cylinder rod. When no hydraulic fluid enters the cylinder cavity, the cylinder rod retracts under the action of the compression spring. Conversely, when hydraulic fluid enters the cylinder cavity, it overcomes the compression spring, causing the cylinder rod to extend.

[0003] The hydraulic circuit of existing pre-retractable single-acting hydraulic cylinders typically consists of: holes drilled in the outer wall of the cylinder barrel, connecting to the cylinder cavity, and hydraulic pipe fittings threaded into these holes. The hydraulic system is then connected to the hydraulic pipe fittings via pipelines.

[0004] The existing hydraulic circuit of the pre-retractable single-acting hydraulic cylinder still has the following problems: the hole is located on the side wall of the cylinder barrel, and there is no piston rod directly opposite the cylinder rod. When the oil enters the cylinder cavity and pushes the cylinder rod to extend, or when the spring is compressed and the cylinder rod retracts and pushes the oil out of the cylinder cavity, the oil movement is unstable. The unstable oil movement, coupled with the thin cylinder barrel wall, results in a shallow hole, which may damage the threaded connection between the hydraulic pipe joint and the hole. In particular, when the hole is damaged, it is difficult to repair and requires the cylinder barrel to be replaced, which is very inconvenient to operate. Utility Model Content

[0005] This application provides a pre-retractable single-acting hydraulic cylinder that can solve the problems mentioned in the background art.

[0006] This application provides a pre-retracted single-acting hydraulic cylinder, comprising:

[0007] The cylinder has a guide hole at the head end that connects to the cylinder cavity, and a second mounting hole at the tail end that connects to the cylinder cavity. The second mounting hole has an internal thread.

[0008] The cylinder rod is stepped and includes: an extended portion that fits into a guide hole, a piston portion that fits into the cylinder cavity, and a slidably connected to the cylinder barrel;

[0009] A compression spring is sleeved on the cylinder rod, with one side abutting against the first interface at the cylinder head end and the other side abutting against the shoulder of the cylinder rod at the piston part;

[0010] The pipe fitting is T-shaped, with a first part having a plug hole and a second part having a first connection hole, the first connection hole communicating with the plug hole;

[0011] The connector includes: a hollow cylindrical section and a stop block integrally disposed at the tail end of the cylindrical section; the cylindrical section has a first external thread, which passes through the insertion hole and is threadedly connected to the second mounting hole, and the pipe joint is fixedly connected between the stop block and the cylinder; the outer wall of the cylindrical section also has a second connecting hole that communicates with the hollow area, and the first connecting hole, the second connecting hole, and the hollow area form an oil passage that communicates with the cylinder.

[0012] In some embodiments, the cylinder includes: a cylinder body and a guide sleeve; the cylinder body has a first mounting hole at its head end, the inner diameter of which is larger than the outer diameter of the piston portion; the guide sleeve is threaded to the first mounting hole, and the guide hole is disposed on the guide sleeve; a second mounting hole is disposed at the tail end of the cylinder body, the inner diameter of which is smaller than the outer diameter of the piston portion, forming a second interface for the piston portion to abut against.

[0013] In some embodiments, a cavity is formed between the insertion hole and the cylindrical segment; the second connection hole is a through hole that penetrates the opposite sides of the outer wall of the cylindrical segment, and the axis of the second connection hole is also perpendicular to the axis of the first connection hole.

[0014] In some embodiments, there are two second connecting holes, one above the other; the outer wall of the cylindrical section of the connector also has an annular protrusion between the two second connecting holes.

[0015] In some embodiments, the outer wall of the cylinder has a second external thread.

[0016] In some embodiments, the outer wall of the cylinder has two opposing notches at the tail end, forming two opposing first planes; the first part of the pipe joint and the stop of the connector are the same regular hexagon; the first part of the pipe joint and the stop of the connector both coincide at the two first planes.

[0017] In some embodiments, it further includes: a gasket; the gasket is fitted onto the cylindrical section of the connector and is located between the cylinder and the pipe fitting.

[0018] In some embodiments, the cylinder rod further includes a limiting portion; the limiting portion is located between the protruding portion and the piston portion, and the diameter of the limiting portion is larger than the diameter of the protruding portion but smaller than the diameter of the piston portion.

[0019] In summary, this application discloses a pre-retracted single-acting hydraulic cylinder comprising: a cylinder barrel, a cylinder rod, a compression spring, a pipe joint, and a connecting body. The hydraulic system is connected to a first connecting hole via a pipeline. Through a solenoid valve, the pipeline switches between two states: an inlet pipe connecting the oil circuit and the hydraulic system, and a return pipe connecting the oil circuit and the hydraulic system. When the pipeline is the inlet pipe connecting the oil circuit and the hydraulic system, oil from the tank enters the cylinder barrel through the oil pipe and oil circuit. The hollow area faces the piston portion of the cylinder rod, allowing the cylinder rod to extend stably against the compression spring. When the pipeline is the return pipe connecting the oil circuit and the hydraulic system, the cylinder rod retracts to its original position under the action of the compression spring, and oil in the cylinder cavity is stably pushed back to the tank through the oil circuit and oil pipe. In case of a malfunction in the oil circuit, the connecting body and pipe joint can be disassembled for convenient maintenance and parts replacement. Attached Figure Description

[0020] To better illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application or the background art will be described below.

[0021] Figure 1 This is a schematic diagram of the present application;

[0022] Figure 2 This is a cross-sectional view of this application;

[0023] Figure 3 A schematic diagram showing the assembly of the cylinder body and guide sleeve into a cylinder barrel;

[0024] Figure 4 This is a schematic diagram of the hydraulic cylinder rod;

[0025] Figure 5 This is a schematic diagram of a pipe fitting;

[0026] Figure 6 This is a schematic diagram of the connector;

[0027] Figure 7 This is a schematic diagram of a gasket between a pipe joint and a cylinder.

[0028] Figure 8 This is a schematic diagram of the second sealing rings at two locations on the connector.

[0029] In the picture,

[0030] 1. Cylinder barrel; 11. Cylinder body; 12. Guide sleeve; 1A. Guide hole; 1B. Second mounting hole; 1C. Cylinder cavity; 1D. First interface; 1E. Second interface; 1F. First mounting hole; 1G. Second external thread; 1H. First plane;

[0031] 2. Cylinder rod; 21. Extended part; 22. Piston part; 23. Limiting part; 2A. First sealing ring; 2B. Shoulder;

[0032] 3. Compression spring;

[0033] 4. Pipe fitting; 41. First part; 42. Second part; 4A. Insertion hole; 4B. First connection hole;

[0034] 5. Connector; 51. Cylindrical section; 52. Stop; 5A. Hollow area; 5B. First external thread; 5C. Second connecting hole; 5D. Second sealing ring; 5E. Annular protrusion;

[0035] 6. Gaskets. Specific Implementation

[0036] The following description is provided in conjunction with the accompanying drawings, which are for illustrative purposes only and not strictly to scale. Unless otherwise defined, the technical or scientific terms used in this disclosure should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. Unless otherwise specified, the embodiments in this application can be combined with each other.

[0037] Please see Figure 1 and Figure 2 A pre-retractable single-acting hydraulic cylinder includes: a cylinder barrel 1, a cylinder rod 2, a compression spring 3, a pipe joint 4, and a connecting body 5.

[0038] The cylinder 1 has a guide hole 1A at its head end and a second mounting hole 1B at its tail end. Both the guide hole 1A and the second mounting hole 1B are connected to the cylinder cavity 1C of the cylinder 1. The second mounting hole 1B also has an internal thread for threaded connection to the subsequent connecting body 5.

[0039] Please see Figure 4 The cylinder rod 2 is stepped. The cylinder rod 2 includes: a protruding portion 21 that mates with the guide hole 1A, and a piston portion 22 that mates with the cylinder cavity 1C. More specifically, the protruding portion 21 and the guide hole 1A can be fitted with a clearance fit, and the piston portion 22 and the cylinder cavity 1C can be fitted with a transition fit. Through the fit between the protruding portion 21 and the guide hole 1A, and the fit between the piston portion 22 and the cylinder cavity 1C, the cylinder rod 2 is slidably connected to the cylinder 1.

[0040] Correspondingly, the piston part 22 is also equipped with a first sealing ring 2A, and the piston part 22 and the cavity wall of the cylinder 1C remain sealed during the linear movement of the cylinder rod 2 relative to the cylinder 1.

[0041] Qing Reference Figure 2 The compression spring 3 is sleeved on the cylinder rod 2. One side of the compression spring 3 abuts against the first interface 1D at the head end of the cylinder 1, and the other side abuts against the shoulder 2B of the cylinder rod 2 at the piston part 22.

[0042] Correspondingly, when no oil is introduced into the cylinder cavity 1C, under the action of the compression spring 3, the piston part 22 of the cylinder rod 2 abuts against the second interface 1E at the tail end of the cylinder 1.

[0043] In some embodiments, the inner diameter of the second mounting hole 1B may be larger than the inner diameter of the cylinder cavity 1C. Accordingly, the cylinder 1 is integral, and a first interface 1D is naturally formed at the junction of the cylinder cavity 1C and the guide hole 1A.

[0044] That is, the compression spring 3 and the cylinder rod 2 are first inserted into the cylinder cavity 1C through the second mounting hole 1B, and the connecting body 5 is then threaded to the second mounting hole 1B, and the end face of the pipe joint 4 forms the second interface 1E.

[0045] Qing Reference Figure 2 and Figure 3 In some embodiments, the inner diameter of the second mounting hole 1B may be smaller than the outer diameter of the piston portion 22. Correspondingly, the cylinder 1 is an assembly type, comprising a cylinder body 11 and a guide sleeve 12. The head end of the cylinder body 11 has a first mounting hole 1F, the inner diameter of which is larger than the outer diameter of the piston portion 22. The guide sleeve 12 is threaded to the first mounting hole 1F, and a guide hole 1A is provided in the guide sleeve 12. The second mounting hole 1B is provided at the tail end of the cylinder body 11, and a second interface 1E is naturally formed at the junction of the cylinder cavity 1C and the second mounting hole 1B.

[0046] That is, the compression spring 3 and the cylinder rod 2 are first inserted into the cylinder cavity 1C through the first mounting hole 1F, and the guide sleeve 12 is then threaded to the first mounting hole 1F, and the end face of the guide sleeve 12 forms the first interface 1D.

[0047] Preferably, the embodiment in which "the inner diameter of the second mounting hole 1B is smaller than the outer diameter of the piston part 22" is adopted, so that the second interface 1E is integrally formed, the piston part 22 of the cylinder rod 2 does not abut against the end face of the connecting body 5, and the threaded connection between the connecting body 5 and the second mounting hole 1B is more stable.

[0048] Qing Reference Figure 2 and Figure 4In some embodiments, the cylinder rod 2 further includes a limiting portion 23. The limiting portion 23 is located between the protruding portion 21 and the piston portion 22. The diameter of the limiting portion 23 is larger than the diameter of the protruding portion 21 and smaller than the diameter of the piston portion 22.

[0049] The limiting part 23 restricts the length that the cylinder rod 2 can extend, leaving a suitable space for the compression spring 3.

[0050] Please see Figure 2 and Figure 5 The pipe connector 4 is T-shaped and includes a first part 41 and a second part 42. The first part 41 has a plug hole 4A, and the second part 42 has a first connection hole 4B, which communicates with the plug hole 4A.

[0051] Please see Figure 2 and Figure 6 The connecting body 5 includes a cylindrical segment 51 and a stop block 52. The cylindrical segment 51 is hollow and has a hollow region 5A inside. The stop block 52 is integrally disposed at the tail end of the cylindrical segment 51. That is, the tail end of the hollow region 5A is closed, and the head end is open to the outside.

[0052] The cylindrical section 51 has a first external thread 5B. The cylindrical section 51 passes through the insertion hole 4A and is threaded to the second mounting hole 1B, fixing the pipe joint 4 between the stop block 52 and the cylinder 1, that is, the stop block 52 and the cylinder 1 respectively abut the pipe joint 4 from both ends.

[0053] The outer wall of the cylindrical section 51 also has a second connecting hole 5C that connects to the hollow region 5A. After the connector 5 and the pipe fitting 4 are connected to the cylinder 1, the second connecting hole 5C is located in the insertion hole 4A of the pipe fitting 4 and also corresponds to the first connecting hole 4B. The first connecting hole 4B, the second connecting hole 5C, and the hollow region 5A form an oil passage that connects to the cylinder 1.

[0054] Correspondingly, the outer wall of the cylindrical section 51 has a second sealing ring 5D near the stop 52 to seal between the connector 5 and the pipe joint 4.

[0055] Please see Figure 8 In some embodiments, the outer wall of the cylindrical segment 51 also has a second sealing ring 5D at a position away from the stop block 52, and the second connecting hole 5C is between the two second sealing rings 5D. After the connector 5 and the pipe joint 4 are connected to the cylinder 1, the two second sealing rings 5D are respectively attached to the inner walls of the insertion hole 4A on both sides of the first connecting hole 4B.

[0056] Please see Figure 7 In some embodiments, the single-acting cylinder further includes a gasket 6. The gasket 6 is fitted onto the cylindrical section 51 of the connecting body 5, located between the cylinder barrel 1 and the pipe joint 4. Accordingly, a third sealing ring is embedded on both end faces of the gasket 6.

[0057] During the installation or removal of the cylindrical section 51 and the pipe fitting 4, the second sealing ring 5D, located away from the stop block 52, needs to pass through the junction of the first connecting hole 4B and the insertion hole 4A, which is easily damaged and affects the sealing effect. Therefore, the embodiment of "gasket 6" is preferred to better ensure the sealing effect and service life.

[0058] The hydraulic system is connected to the first connection port 4B via a pipeline. A solenoid valve switches the pipeline between two states: an inlet pipe connecting the oil circuit and the hydraulic system, and a return pipe connecting the oil circuit and the hydraulic system. When the pipeline is the inlet pipe connecting the oil circuit and the hydraulic system, oil from the tank enters the cylinder 1 through the oil pipe and oil circuit. The hollow region 5A faces the piston portion 22 of the cylinder rod 2, allowing the cylinder rod 2 to extend stably against the action of the compression spring 3. When the pipeline is the return pipe connecting the oil circuit and the hydraulic system, the cylinder rod 2 retracts back to its original position under the action of the compression spring 3, and the oil in the cylinder cavity 1C is stably pushed back to the tank through the oil circuit and oil pipe. Correspondingly, if it is necessary to keep the cylinder rod 2 in a certain extended or retracted position, a three-position solenoid valve is selected, allowing the pipeline to also have the following state: sealing the end connecting the pipeline and the solenoid valve, thus cutting off the connection between the oil circuit and the hydraulic system.

[0059] In some embodiments, the cylindrical segment 51 is fitted to the inner wall of the insertion hole 4A, and the axis of the second connecting hole 5C coincides with the axis of the first connecting hole 4B.

[0060] Please see Figure 2 and Figure 7 In some embodiments, a cavity is formed between the insertion hole 4A and the cylindrical section 51. The second connecting hole 5C is a through hole that penetrates to opposite sides of the outer wall of the cylindrical section 51. The axis of the second connecting hole 5C is also perpendicular to the axis of the first connecting hole 4B. That is, the oil enters from the inlet of the first connecting hole 4B, first fills the cavity, and then enters the hollow region 5A of the cylindrical section 51 from the second connecting hole 5C.

[0061] A preferred embodiment employs a cavity formed between the insertion hole 4A and the cylindrical section 51. The oil flows directly from the first connection hole 4B into the second connection hole 5C, and then into the hollow region 5A of the cylindrical section 51, similar to passing through a turning point. The cavity design acts as a buffer, allowing the oil to more stably flow from the second connection hole 5C into the hollow region 5A of the cylindrical section 51.

[0062] Please see Figure 2 and Figure 7 Based on the above embodiment where "a cavity is formed between the insertion hole 4A and the cylindrical segment 51", in some embodiments, there are two second connecting holes 5C, one above the other. The outer wall of the cylindrical segment 51 of the connector 5 also has an annular protrusion 5E, which is located between the two second connecting holes 5C.

[0063] Please see Figure 1 In some embodiments, the outer wall of cylinder 1 has a second external thread 1G.

[0064] By setting threaded holes on the corresponding parts, the single-acting cylinder can be installed on the parts more conveniently through the second thread.

[0065] Please see Figure 1 Based on the above embodiment where "the outer wall of cylinder 1 has a second external thread 1G", in some embodiments, the outer wall of cylinder 1 has two opposing notches at the tail end, forming two opposing first planes 1H. The first part 41 of pipe connector 4 and the stop 52 of connector 5 are the same regular hexagon, that is, the first part 41 of pipe connector 4 and the stop 52 of connector 5 both have six second planes. The first part 41 of pipe connector 4 and the stop 52 of connector 5 both coincide with two first planes 1H.

[0066] During the installation or disassembly of single-acting cylinders and components, a tool with a notch can be used. The inner wall of one side of the notch is fitted against a first plane 1H and two second planes that coincide with the first plane 1H, while the inner wall of the other side is fitted against another first plane 1H and two second planes that coincide with the first plane 1H. This ensures the assembly and connection between the cylinder barrel 1, the connecting body 5, and the pipe joint 4.

[0067] In conjunction with the above embodiment of "forming a cavity between the insertion hole 4A and the cylindrical section 51", when the connector 5 is tightened until the stop 52 coincides with the first part 41, the axis of the second connection hole 5C is perpendicular to the axis of the first connection hole 4B.

Claims

1. A pre-retractable single-acting hydraulic cylinder, characterized in that, include: The cylinder (1) has a guide hole (1A) at the head end that communicates with the cylinder cavity (1C) and a second mounting hole (1B) at the tail end that communicates with the cylinder cavity (1C). The second mounting hole (1B) has an internal thread. The cylinder rod (2) is stepped and includes: an extended portion (21) that fits into the guide hole (1A) and a piston portion (22) that fits into the cylinder cavity (1C); it is slidably connected to the cylinder (1); A compression spring (3) is sleeved on the cylinder rod (2), with one side abutting the first interface (1D) at the head end of the cylinder (1), and the other side abutting the shoulder (2B) of the cylinder rod (2) on the piston part (22); The pipe fitting (4) is T-shaped, with a first part (41) having a plug hole (4A) and a second part (42) having a first connection hole (4B), the first connection hole (4B) being connected to the plug hole (4A); The connector (5) includes: a hollow cylindrical section (51) and a stop (52) integrally disposed at the tail end of the cylindrical section (51); the cylindrical section (51) has a first external thread (5B), which passes through the insertion hole (4A) and is threadedly connected to the second mounting hole (1B); the pipe connector (4) is fixedly connected between the stop (52) and the cylinder (1); the outer wall of the cylindrical section (51) also has a second connecting hole (5C) that connects to the hollow area (5A); the first connecting hole (4B), the second connecting hole (5C), and the hollow area (5A) form an oil passage that connects to the cylinder (1).

2. A pre-retractable single-acting hydraulic cylinder according to claim 1, characterized in that, The cylinder (1) includes: a cylinder body (11) and a guide sleeve (12); the cylinder body (11) has a first mounting hole (1F) at its head end, the inner diameter of the first mounting hole (1F) being larger than the outer diameter of the piston part (22); the guide sleeve (12) is threaded to the first mounting hole (1F), and a guide hole (1A) is provided in the guide sleeve (12); a second mounting hole (1B) is provided at the tail end of the cylinder body (11), the inner diameter of the second mounting hole (1B) being smaller than the outer diameter of the piston part (22), forming a second interface (1E) for the piston part (22) to abut against.

3. A pre-retractable single-acting hydraulic cylinder according to claim 1, characterized in that, A cavity is formed between the insertion hole (4A) and the cylindrical section (51); the second connecting hole (5C) is a through hole that penetrates the opposite sides of the outer wall of the cylindrical section (51), and the axis of the second connecting hole (5C) is also perpendicular to the axis of the first connecting hole (4B).

4. A pre-retractable single-acting hydraulic cylinder according to claim 3, characterized in that, There are two second connecting holes (5C), one above the other; the outer wall of the cylindrical section (51) of the connecting body (5) also has an annular protrusion (5E), which is located between the two second connecting holes (5C).

5. A pre-retractable single-acting hydraulic cylinder according to claim 1, characterized in that, The outer wall of the cylinder (1) has a second external thread (1G).

6. A pre-retractable single-acting hydraulic cylinder according to claim 5, characterized in that, The outer wall of the cylinder (1) has two opposing notches at the tail end, forming two opposing first planes (1H); the first part (41) of the pipe joint (4) and the stop (52) of the connector (5) are the same regular hexagon; the first part (41) of the pipe joint (4) and the stop (52) of the connector (5) both coincide at the two first planes (1H).

7. A pre-retractable single-acting hydraulic cylinder according to claim 1, characterized in that, Also includes: Gasket (6); The gasket (6) is fitted onto the cylindrical section (51) of the connector (5) and is located between the cylinder (1) and the pipe joint (4).

8. A pre-retractable single-acting hydraulic cylinder according to claim 1, characterized in that, The cylinder rod (2) also includes a limiting part (23); the limiting part (23) is located between the protruding part (21) and the piston part (22), and the diameter of the limiting part (23) is larger than the diameter of the protruding part (21) and smaller than the diameter of the piston part (22).

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