Oil cylinder and engineering machinery

Abstract

The utility model relates to the technical field of engineering machinery, and discloses an oil cylinder and engineering machinery, and the oil cylinder comprises a cylinder barrel, a piston rod and a plugging piece. The cylinder barrel is provided with a channel, and an oil passing opening is formed in the side wall of the inner periphery of the channel. The piston rod is slidably arranged in the channel in the axial direction of the channel, the end face, located in the cylinder barrel, of the piston rod is provided with a first throttling part, and an oil passing hole is formed in the piston rod. The plugging piece is arranged at the end, close to the first throttling part, of the channel, the side face, facing the first throttling part, of the plugging piece is provided with a second throttling part, a first cavity is formed between the two opposite faces of the plugging piece and the piston rod, and the oil passing hole communicates with the first cavity and the oil passing opening. The first throttling part is located between the peripheral side wall of the second throttling part and the inner peripheral side wall of the cylinder barrel, a second cavity is formed between the first throttling part and the side face, facing the first throttling part, of the plugging piece, at least one of the first throttling part and the second throttling part is provided with a throttling groove, and the throttling groove communicates with the first cavity and the second cavity. The structure for achieving in-place buffering can be simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering machinery, and in particular to an oil cylinder and engineering machinery. BACKGROUND

[0002] The swing valve oil cylinder is the core executive element of the material conveying mechanism of engineering machinery such as a concrete pump truck, and undertakes the key task of driving the swing valve to reverse and coordinating material conveying. Such an oil cylinder is usually arranged in pairs and symmetrically, and needs to continuously act under high pressure and high frequency (the action frequency can be more than 20 times / min), and the dynamic characteristics thereof are directly related to the operating efficiency of the whole machine, the stability of the hydraulic system and the service life of the equipment. Since the swing valve oil cylinder is frequently started and stopped and bears severe vibration, the advantages and disadvantages of the buffering performance thereof not only affect the fatigue life of the mechanical structure, but also significantly affect the comfort and health of the operator through vibration transmission, and therefore strict requirements are put forward for the buffering effect and starting pressure control.

[0003] At present, two types of technical solutions are mainly used for the buffering design of the swing valve oil cylinder in the industry: one type is an external check valve cooperating with a throttling buffering structure, which controls the oil flow path through the external check valve to form a throttling damping at the end of the stroke to realize the deceleration buffering; and the other type is an internal floating buffering structure, which utilizes the movable buffering ring inside the piston to cooperate with the cylinder body to generate a gradual damping effect when approaching the end of the stroke.

[0004] However, the external check valve scheme has low cost, but has problems such as oil leakage due to vibration loosening of the valve body, blockage of the check valve by impurities, and significant attenuation of the buffering effect after long-term use, while the internal floating buffering structure has high machining precision requirements for the internal components (such as the buffering ring and the guide sleeve) and complex assembly process, and once the buffering ring is loosened, it may cause pollution and even jamming failure of the hydraulic system, and the maintenance cost and risk are greatly increased. Therefore, it is urgent to develop a new type of buffering structure which has excellent buffering capacity, low starting pressure characteristics and high environmental adaptability while simplifying the design and reducing the cost, so as to solve the core defects of the prior art. CONTENT OF THE INVENTION

[0005] The present application provides an oil cylinder and engineering machinery to solve the problem of complex structure in the prior art.

[0006] In a first aspect, the application provides an oil cylinder, comprising a cylinder barrel, a piston rod and a blocking piece. The cylinder barrel is provided with a passage, and an oil passage is arranged on the inner circumferential wall of the passage. The piston rod is slidably arranged in the passage along the axial direction of the passage, and the end face of the piston rod located in the cylinder barrel is provided with a first throttling part, and the piston rod is provided with an oil passage hole. The blocking piece is arranged at one end of the passage close to the first throttling part, and the side face of the blocking piece facing the first throttling part is provided with a second throttling part. A first cavity is arranged between the two opposite faces of the blocking piece and the piston rod, and the oil passage hole is connected with the first cavity and the oil passage. Wherein, the first throttling part is located between the peripheral side wall of the second throttling part and the inner circumferential wall of the cylinder barrel, and a second cavity is formed between the first throttling part and the side face of the blocking piece facing the first throttling part. At least one of the first throttling part and the second throttling part is provided with a throttling groove, and the throttling groove connects the first cavity and the second cavity.

[0007] Beneficial effects: The nested throttling design of the first throttling part of the end face of the piston rod and the second throttling part of the blocking piece is adopted, and the first cavity and the second cavity are connected through the throttling groove, so that progressive buffering without external valve is realized. The closed loop oil circuit is formed by the double cavity structure and the oil passage hole, and the dynamic pressure gradient is established at the end of the stroke, so that the buffering stability can be ensured.

[0008] In an optional embodiment, the first throttling part is arranged in a ring structure, the peripheral side wall of the first throttling part is in sliding contact with the inner wall of the passage, the second throttling part is arranged in a column structure, the peripheral side wall of the second throttling part is in sliding contact with the inner circumferential wall of the first throttling part, and the cavity surrounded by the first throttling part forms the first cavity.

[0009] Beneficial effects: The second cavity is surrounded by the end face of the first throttling part facing the blocking piece, the end face of the blocking piece facing the first throttling part, the peripheral side wall of the second throttling part and the inner wall of the passage. The sliding cooperation of the ring structure of the first throttling part and the column structure of the second throttling part can adjust the space size of the second cavity. When the piston rod is retracted, the space of the second cavity becomes smaller, and the oil in the second cavity is pressed into the first cavity through the throttling groove, which can play a buffering effect.

[0010] In an optional embodiment, the inner circumferential wall of the passage is provided with an oil guide groove, the extension direction of the oil guide groove is parallel to the axial direction of the passage, and the oil guide groove connects the oil passage and the oil passage hole.

[0011] Beneficial effects: The oil guide groove extends along the axial direction of the passage, so that the oil passage hole and the oil passage can always maintain a connected state during the movement of the piston rod, thereby realizing the extension and retraction actions of the piston rod.

[0012] In an alternative embodiment, the oil guide groove is arranged in a ring structure, and the oil guide groove is coaxial with the axis of the passage.

[0013] Beneficial effects: arranging the oil guide groove in a ring structure can ensure that the oil passage hole and the oil passage opening are still connected when they are circumferentially staggered, thereby improving adaptability.

[0014] In an alternative embodiment, the oil passage hole is provided with a first hole and a second hole, the first hole penetrates the piston rod in a direction perpendicular to the axial direction of the piston rod, and the first hole is connected to the oil guide groove, and the second hole is connected to the first hole and the second cavity.

[0015] Beneficial effects: by arranging the first hole to penetrate the piston rod in a radial direction, and cooperating with the ring structure of the oil guide groove, both openings of the first hole can be connected to the oil guide groove, thereby increasing the oil inlet and outlet, accelerating the response rate of the piston rod, and improving work efficiency.

[0016] In an alternative embodiment, the sealing member further comprises a connecting portion and a sealing portion, the connecting portion, the sealing portion and the first throttling portion are sequentially connected along the axial direction of the passage, the peripheral surface of the sealing portion is attached to the inner wall of the passage, the projected area of the sealing portion on the side surface of the connecting portion is smaller than the area of the side surface of the connecting portion, so that the sealing portion is located within the coverage range of the connecting portion, and the connecting portion is connected to the end surface of the cylinder barrel.

[0017] Beneficial effects: the sealing portion can be attached to the inner wall of the passage to achieve sealing effect, and the connecting portion can be connected to the outer wall of the cylinder barrel, so that the entire connection process is completed outside the cylinder barrel, improving the convenience of connecting the sealing member to the cylinder barrel.

[0018] In an alternative embodiment, an oil nozzle is further provided, which is arranged on the peripheral side wall of the cylinder barrel, and the inner cavity of the oil nozzle is connected to the oil passage opening, and the oil nozzle is adapted to be connected to an external oil circuit.

[0019] Beneficial effects: the oil nozzle can supply hydraulic oil to the oil passage opening, thereby improving work efficiency.

[0020] In an alternative embodiment, the oil nozzle is arranged in a cylindrical structure, and the oil nozzle is welded to the peripheral side wall of the cylinder barrel.

[0021] Beneficial effects: arranging the oil nozzle in a cylindrical structure can achieve the connection between the inner cavity of the oil nozzle and the oil passage opening.

[0022] In an alternative embodiment, a sealing member is arranged between the peripheral side wall of the piston rod and the inner peripheral side wall of the passage, and the sealing member is located at one end away from the first throttling portion along the axial direction of the passage.

[0023] Beneficial effects: the arrangement of the sealing member can realize the sealing effect between the outer wall of the piston rod and the inner wall of the cylinder, avoiding the leakage of hydraulic oil.

[0024] In a second aspect, the application further provides an engineering machine comprising the oil cylinder.

[0025] Since the engineering machine comprises the oil cylinder, the same effects as the oil cylinder are achieved, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed in the description of the specific embodiments or prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Fig. 1 FIG. 1 is a structural schematic diagram of an oil cylinder according to an embodiment of the present application;

[0028] Fig. 2 FIG. 2 is a structural schematic diagram of a piston rod according to an embodiment of the present application;

[0029] Fig. 3 FIG. 3 is a structural schematic diagram of a sealing member according to an embodiment of the present application.

[0030] Explanation of reference signs:

[0031] 1, cylinder; 101, passage; 102, oil passage; 103, oil guide groove; 2, piston rod; 201, first throttling part; 202, oil passage hole; 2021, first hole; 2022, second hole; 3, sealing member; 301, second throttling part; 302, connecting part; 303, sealing part; 4, first cavity; 5, second cavity; 6, oil nozzle; 7, plug; 8, gasket; 9, sealing member; 10, throttling groove. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, but not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0033] The embodiments of the present application will be described below in combination with Figs. 1 to 3 .

[0034] According to the embodiment of the present application, in one aspect, an oil cylinder is provided, which comprises a cylinder barrel 1, a piston rod 2 and a blocking piece 3. The cylinder barrel 1 is provided with a passage 101, and the inner circumferential wall of the passage 101 is provided with an oil passage 102. The piston rod 2 is slidably arranged in the passage 101 along the axial direction of the passage 101, and the end face of the piston rod 2 located in the cylinder barrel 1 is provided with a first throttling part 201, and the piston rod 2 is provided with an oil passage hole 202. The blocking piece 3 is arranged at one end of the passage 101 close to the first throttling part 201, and the side face of the blocking piece 3 facing the first throttling part 201 is provided with a second throttling part 301, and a first cavity 4 is arranged between the two opposite faces of the blocking piece 3 and the piston rod 2, and the oil passage hole 202 communicates the first cavity 4 and the oil passage 102. Wherein, the first throttling part 201 is located between the peripheral side wall of the second throttling part 301 and the inner circumferential wall of the cylinder barrel 1, and a second cavity 5 is formed between the first throttling part 201 and the side face of the blocking piece 3 facing the first throttling part 201, and at least one of the first throttling part 201 and the second throttling part 301 is provided with a throttling groove 10, and the throttling groove 10 communicates the first cavity 4 and the second cavity 5.

[0035] It can be understood that when the piston rod 2 performs the arm retraction action and constitutes the second cavity 5, the arrangement of the throttling groove 10 can slow down the flow rate of the hydraulic oil flowing from the second cavity 5 to the first cavity 4, thereby increasing the oil pressure in the first cavity 4, and slowing down the movement speed of the piston rod 2, and finally achieving the buffering effect. With the continuous movement of the piston rod 2 (in the direction close to the blocking piece 3), the length of the fit between the first throttling part 201 and the second throttling part 301 gradually increases, at this time, the length of the throttling passage 101 formed by the slot opening of the blocking throttling groove 10 also gradually increases, forming a dynamic throttling path, and the speed of the hydraulic oil flowing from the second cavity 5 to the first cavity 4 will also gradually decrease, so that the movement speed of the piston rod 2 will also gradually slow down, until reaching the preset position and stopping moving.

[0036] It should be noted that when the piston rod 2 is retracted, the space of the second cavity 5 becomes smaller, and the oil can be normally returned through the oil port 102, when the piston rod 2 moves to the position of the oil passage 102, the second cavity 5 and the oil passage 102 are cut off, and the oil in the second cavity 5 cannot be directly returned through the oil port 102, but can only be returned through the throttling groove 10, further, the oil in the second cavity 5 is pressed into the first cavity 4 through the throttling groove 10, and then enters the oil passage 102 through the oil hole 202 to return the oil, thereby achieving the buffering effect.

[0037] Optionally, the rod diameter of the piston rod 2 is the same as the inner diameter of the channel 101, so that the two are in sliding fit, further increasing the starting area of the piston rod 2, which can make the piston rod 2 respond quickly, while the hydraulic oil enters the first cavity 4 to push the piston rod 2 to move outward when the piston rod 2 moves outward (i.e. when the arm is extended), the throttle groove 10 is arranged to reduce the speed of the hydraulic oil entering the second cavity 5, which can effectively reduce the starting impact, and as the piston rod 2 gradually moves outward, the length of the throttle channel 101 also gradually decreases, so that the moving speed of the piston rod 2 also gradually increases until the first throttle part 201 and the second throttle part 301 reach the maximum moving speed.

[0038] Optionally, the throttle groove 10 can be arranged as a spiral ring groove, or a straight groove parallel to the axial direction of the piston rod 2.

[0039] Optionally, direct guiding and supporting are adopted by using the cylinder 1, and the arrangement of the guide sleeve and the piston is abandoned, so that the cost is low and the structure is simple.

[0040] In this embodiment, the nested throttle design of the first throttle part 201 on the end face of the piston rod 2 and the second throttle part 301 of the sealing member 3 is adopted, and the first cavity 4 and the second cavity 5 are connected through the throttle groove 10, so that the progressive buffering without external valve is realized. The closed-loop oil circuit is formed by the double-cavity structure and the oil passage hole 202, and the dynamic pressure gradient is established at the end of the stroke, which can ensure the stability of the buffering.

[0041] In one embodiment, the first throttle part 201 is arranged in a ring structure, and the peripheral side wall of the first throttle part 201 is in sliding contact with the inner wall of the channel 101, the second throttle part 301 is arranged in a columnar structure, and the peripheral side wall of the second throttle part 301 is in sliding contact with the inner peripheral side wall of the first throttle part 201, and the cavity surrounded by the first throttle part 201 forms the first cavity 4.

[0042] Optionally, the first throttle part 201 and the second throttle part 301 can be arranged in a columnar structure with a semicircular cross section, and the first throttle part 201 and the second throttle part 301 can form a complete columnar structure, the two planes of the first throttle part 201 and the second throttle part 301 are attached to each other, and the throttle groove 10 is arranged on one of the two planes.

[0043] In this embodiment, the end face of the first throttle part 201 facing the sealing member 3, the end face of the sealing member 3 facing the first throttle part 201, the peripheral side wall of the second throttle part 301 and the inner wall of the channel 101 form the second cavity 5, and the sliding fit of the ring structure of the first throttle part 201 and the columnar structure of the second throttle part 301 can adjust the space size of the second cavity 5, when the piston rod 2 is retracted, the space of the second cavity 5 becomes smaller, and then the oil in the second cavity 5 is pressed into the first cavity 4 through the throttle groove 10, which can play a buffering effect.

[0044] In one embodiment, the inner circumferential wall of the channel 101 is provided with an oil guide groove 103, the extension direction of the oil guide groove 103 is parallel to the axial direction of the channel 101, and the oil guide groove 103 is connected with the oil port 102 and the oil passing hole 202.

[0045] In this embodiment, the oil guide groove 103 extends along the axial direction of the channel 101, so that the oil passing hole 202 and the oil passing port 102 can always be in a communication state during the movement of the piston rod 2, thereby realizing the extension and retraction actions of the piston rod 2.

[0046] In one embodiment, the oil guide groove 103 is provided in a ring structure, and the oil guide groove 103 coincides with the axis of the channel 101.

[0047] In this embodiment, the oil guide groove 103 is provided in a ring structure, which can ensure that the oil passing hole 202 and the oil passing port 102 can still be in communication when they are circumferentially staggered, thereby improving the adaptability.

[0048] In one embodiment, the oil passing hole 202 is provided with a first hole 2021 and a second hole 2022, the first hole 2021 penetrates the piston rod 2 in a direction perpendicular to the axial direction of the piston rod 2, and the first hole 2021 is in communication with the oil guide groove 103, and the second hole 2022 is in communication with the first hole 2021 and the second cavity 5.

[0049] Optionally, the second hole 2022 can be provided with a plurality of hole openings, and the plurality of hole openings are arranged on the peripheral wall of the piston rod 2 in a circumferential direction of the piston rod 2, thereby realizing the communication with the oil guide groove 103.

[0050] Optionally, the first hole 2021 can be provided with a plurality of first holes 2021, and the plurality of first holes 2021 are in communication with the second hole 2022, and the plurality of first holes 2021 are in communication with the first cavity 4.

[0051] In this embodiment, by providing the first hole 2021 in a structure penetrating the piston rod 2 in a radial direction, and cooperating with the ring structure of the oil guide groove 103, both hole openings of the first hole 2021 can be in communication with the oil guide groove 103, thereby increasing the oil inlet and outlet amounts, accelerating the response rate of the piston rod 2, and improving the working efficiency.

[0052] In one embodiment, the blocking member 3 further has a connecting portion 302 and a blocking portion 303, the connecting portion 302, the blocking portion 303 and the first throttling portion 201 are sequentially connected in the axial direction of the channel 101, the peripheral surface of the blocking portion 303 is attached to the inner wall of the channel 101, the projected area of the blocking portion 303 on the side surface of the connecting portion 302 is smaller than the side surface area of the connecting portion 302, so that the blocking portion 303 is located within the coverage range of the connecting portion 302, and the connecting portion 302 is connected with the end surface of the cylinder barrel 1.

[0053] Optionally, the blocking member 3 can further be provided with a holding portion for holding when the connecting portion 302 is connected with the outer wall of the cylinder barrel 1, facilitating operation, and the holding portion can be provided in a spherical structure.

[0054] Optionally, the connecting portion 302 is welded with the outer wall of the cylinder barrel 1.

[0055] In the embodiment, the blocking portion 303 is provided to realize adhesion to the inner wall of the passage 101, achieving sealing effect, and the connecting portion 302 is provided to realize connection with the outer wall of the cylinder barrel 1, so that the entire connection process is completed outside the cylinder barrel 1, improving the convenience of connection of the blocking member 3 with the cylinder barrel 1.

[0056] In one embodiment, the oil nozzle 6 is further provided on the peripheral side wall of the cylinder barrel 1, and the inner cavity of the oil nozzle 6 is in communication with the oil passage 102, and the oil nozzle 6 is adapted to be connected with an external oil circuit. The oil nozzle 6 is provided in a cylindrical structure, and the oil nozzle 6 is welded with the peripheral side wall of the cylinder barrel 1.

[0057] In the embodiment, the oil nozzle 6 is provided to realize supply of hydraulic oil to the oil passage 102, improving work efficiency. The oil nozzle 6 is provided in a cylindrical structure, and the inner cavity of the oil nozzle 6 is in communication with the oil passage 102.

[0058] In one embodiment, the screw plug 7 and the gasket 8 are further provided, the screw plug 7 is detachably connected in the oil nozzle 6, specifically, the first end of the screw plug 7 in the axial direction is arranged in the inner cavity of the oil nozzle 6, the second end of the screw plug 7 in the axial direction is abutted with the end of the oil nozzle 6 away from the cylinder barrel 1, and the gasket 8 is located between the screw plug 7 and the oil nozzle 6.

[0059] Optionally, the gasket 8 can be provided in a rubber pad.

[0060] In the embodiment, the screw plug 7 is used when the cylinder barrel 1 is not connected with the external oil circuit, and is used to achieve sealing effect.

[0061] In one embodiment, the sealing member 9 is arranged between the peripheral side wall of the piston rod 2 and the inner peripheral side wall of the passage 101, and the sealing member 9 is located at the end away from the first throttling portion 201 in the axial direction of the passage 101.

[0062] In the embodiment, the sealing member 9 is provided to realize sealing effect between the outer wall of the piston rod 2 and the inner wall of the cylinder barrel 1, avoiding leakage of hydraulic oil.

[0063] According to the embodiment of the present application, on the other hand, an engineering machine is further provided, comprising the oil cylinder.

[0064] Because the engineering machine comprises the oil cylinder, has the same effect as the oil cylinder, and will not be described here.

[0065] While embodiments of the application have been described in connection with the preferred embodiments of the various figures, those of ordinary skill in the art will appreciate that various modifications and variations of the preferred embodiments can be employed without departing from the spirit and scope of the application.

Claims

1. A cylinder, characterized in that The application relates to a cylinder (1) provided with a passage (101) and an oil passage (102) on the inner circumferential wall of the passage (101); a piston rod (2) slidably arranged in the passage (101) along the axial direction of the passage (101), the end face of the piston rod (2) in the cylinder (1) is provided with a first throttling part (201), and the piston rod (2) is provided with an oil passage hole (202); a blocking piece (3) arranged at one end of the passage (101) close to the first throttling part (201), the side face of the blocking piece (3) towards the first throttling part (201) is provided with a second throttling part (301), and a first cavity (4) is arranged between the two opposite faces of the blocking piece (3) and the piston rod (2), the oil passage hole (202) is communicated with the first cavity (4) and the oil passage (102); wherein the first throttling part (201) is located between the peripheral side wall of the second throttling part (301) and the inner circumferential wall of the cylinder (1), a second cavity (5) is formed between the first throttling part (201) and the side face of the blocking piece (3) towards the first throttling part (201), and at least one of the first throttling part (201) and the second throttling part (301) is provided with a throttling groove (10), the throttling groove (10) is communicated with the first cavity (4) and the second cavity (5). The first throttling part (201) is arranged in a ring structure, the peripheral side wall of the first throttling part (201) is in sliding contact with the inner wall of the passage (101), the second throttling part (301) is arranged in a columnar structure, the peripheral side wall of the second throttling part (301) is in sliding contact with the inner circumferential wall of the first throttling part (201), and the cavity formed by the first throttling part (201) forms the first cavity (4). The inner circumferential wall of the passage (101) is provided with an oil guide groove (103), the extending direction of the oil guide groove (103) is parallel to the axial direction of the passage (101), and the oil guide groove (103) is communicated with the oil passage (102) and the oil passage hole (202). The oil guide groove (103) is arranged in a ring structure, and the oil guide groove (103) is coincident with the axis of the passage (101). The oil passage hole (202) is provided with a first hole channel (2021) and a second hole channel (2022), the first hole channel (2021) penetrates the piston rod (2) along a direction perpendicular to the axial direction of the piston rod (2), the first hole channel (2021) is communicated with the oil guide groove (103), and the second hole channel (2022) is communicated with the first hole channel (2021) and the second cavity (5).

2. The oil cylinder according to claim 1, characterized in that The blocking piece (3) further has 3. The oil cylinder of claim 1, wherein, ​ 4. The oil cylinder of claim 3, wherein, ​ 5. The oil cylinder of claim 4, wherein, ​ 6. The oil cylinder of claim 1, wherein, ​ The connecting part (302) and the blocking part (303) are connected in sequence along the channel (101) in the axial direction, the peripheral surface of the blocking part (303) is in close contact with the inner wall of the channel (101), the projected area of the blocking part (303) on the side surface of the connecting part (302) is less than the area of the side surface of the connecting part (302), so that the blocking part (303) is located in the coverage range of the connecting part (302), and the connecting part (302) is connected with the end surface of the cylinder barrel (1).

7. The oil cylinder of claim 1, wherein Also include: The oil nozzle (6) is arranged on the peripheral side wall of the cylinder barrel (1), and the inner cavity of the oil nozzle (6) is in communication with the oil passage (102), and the oil nozzle (6) is suitable for being connected with an external oil circuit.

8. The oil cylinder of claim 7, wherein, The oil nozzle (6) is arranged in a barrel structure, and the oil nozzle (6) is welded with the peripheral side wall of the cylinder barrel (1).

9. The oil cylinder of claim 1, wherein, A sealing element (9) is arranged between the peripheral side wall of the piston rod (2) and the inner peripheral side wall of the channel (101), and the sealing element (9) is located at one end away from the first throttling part (201) in the axial direction of the channel (101).

10. A working machine, characterized in that Include: The oil cylinder of any one of claims 1 to 9.

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