Double-acting multistage piston cylinder

Abstract

The utility model relates to a multi-stage hydraulic cylinder, in particular to a double-acting multi-stage piston cylinder. Comprising a cylinder barrel, a piston rod is arranged in the cylinder barrel, one end of the piston rod is connected with an inner piston sleeve, and an outer piston sleeve is arranged outside the inner piston sleeve; a first oil port, a second oil port and a third oil port are formed in the surface of the cylinder barrel, and the first oil port is communicated with the second oil port; the outer piston sleeve is provided with a first oil hole and a second oil hole, and hydraulic oil flows into the first oil hole or flows out of the first oil hole from the third oil port. The outer piston sleeve can reciprocate along the two ends of the cylinder barrel in the cylinder barrel, and the inner piston sleeve can reciprocate along the two ends of the outer piston sleeve. A third oil hole and a fourth oil hole are formed in the piston rod; and the hydraulic oil can flow out from the fourth oil hole. After the piston rod retracts, when a replacement part is dismounted or cleaned, the first cavity and the second cavity between the first oil port and the second oil port can completely discharge extending oil.

Description

Technical Field

[0001] The utility model relates to a multi-stage hydraulic cylinder, in particular to a double-acting multi-stage piston cylinder. Background Art

[0002] Telescopic hydraulic cylinder is a hydraulic cylinder with a multi-stage sleeve-shaped piston rod that can obtain a longer working stroke. It is composed of two or more piston hydraulic cylinders. The piston rod of the previous piston cylinder is the cylinder barrel of the next piston cylinder. Telescopic hydraulic cylinder is also called multi-stage hydraulic cylinder. Single-acting multi-stage cylinder can only provide one thrust, and engineering machinery can only perform one operation, requiring external force to control retraction. The working operation performance is poor and the work efficiency is low. A double-acting hydraulic cylinder must be used to complete a complete reciprocating motion. The current devices on the market are inconvenient when entering and exiting the oil, and the process is complicated. It may cause the oil to remain in the oil circuit after it is not drained cleanly, thereby affecting the life of the multi-stage cylinder and the telescopic effect of the hydraulic cylinder. Utility Model Content

[0003] Purpose of the utility model: In order to overcome the deficiencies in the prior art, the utility model provides a multi-stage cylinder that is convenient for discharging hydraulic oil.

[0004] Technical solution: To achieve the above-mentioned purpose, the utility model provides a double-acting multi-stage piston cylinder, comprising a cylinder barrel, a piston rod is arranged in the cylinder barrel, one end of the piston rod is connected to an inner piston sleeve, and an outer piston sleeve is arranged outside the inner piston sleeve; a first oil port, a second oil port, and a third oil port are opened on the surface of the cylinder barrel, and the first oil port and the second oil port are connected to each other; the outer piston sleeve is provided with a first oil hole and a second oil hole, and the hydraulic oil flows into the first oil hole or flows out of the first oil hole from the third oil hole; the outer piston sleeve can reciprocate in the cylinder barrel along the two ends of the cylinder barrel, and the inner piston sleeve can reciprocate along the two ends of the outer piston sleeve; the piston rod is provided with a third oil hole and a fourth oil hole; the hydraulic oil can flow out from the fourth oil hole.

[0005] Furthermore, a first cavity is arranged between the first oil port and the outer piston sleeve, a second cavity is arranged between the first cavity and the second oil port, and the first cavity is communicated with the second cavity; a first hole path is arranged between the third oil port and the first oil hole, a second hole path is arranged between the first oil hole and the second oil hole, and a third hole path is arranged between the second oil hole and the inner piston sleeve; and a fourth hole path is arranged between the third oil hole and the fourth oil hole.

[0006] Furthermore, an end cover is provided at one end of the cylinder barrel, and a guide sleeve is provided at the other end of the cylinder barrel; a sealing block is also provided in the outer piston sleeve, and the sealing block is connected to an end of the outer piston sleeve away from the inner piston sleeve.

[0007] Furthermore, one end of the piston rod close to the third oil hole is provided with a thread; one end of the inner piston sleeve is provided with a thread, and one end of the inner piston sleeve away from the thread is provided with a groove.

[0008] Furthermore, a first sealing ring is provided on the outer piston sleeve, and the first sealing ring is in contact with the cylinder barrel; a second sealing ring is provided on the inner piston sleeve, and the second sealing ring is in contact with the inner wall of the outer piston sleeve; a third sealing ring is provided in the sealing block, and the third sealing ring is in contact with the piston rod; a fourth sealing ring is provided on the piston rod, and the height of the fourth sealing ring exceeds the height of the groove.

[0009] Preferably, a lifting ring is provided on the end cover, and a lifting ring is provided on the end of the piston rod away from the cylinder.

[0010] The beneficial effects of the utility model are:

[0011] 1. The piston rod and the cylinder of the utility model are improved. When the piston rod is retracted and the parts are removed for replacement or cleaning, the first cavity and the second cavity between the first oil port and the second oil port can drain the extended oil, and the fourth oil hole and the fourth hole of the piston rod can drain the oil in the internal retracted oil circuit, so as to avoid oil splashing or solidified oil from clogging the oil circuit during disassembly.

[0012] 2. The utility model ensures that the internal structure forms an oil circuit through the sealing block and the guide sleeve. The sealing block is connected to the outer piston sleeve to avoid scratching the housing and the guide sleeve to avoid leakage; the first sealing ring, the second sealing ring, and the third sealing ring optimize the sealing performance; the cooperation of the inner piston sleeve and the fourth sealing ring ensures that the third oil hole is not normally open, thereby enhancing the sealing performance inside the oil cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the utility model;

[0014] Figure 2 It is a structural sectional view of the utility model;

[0015] Figure 3 It is a schematic diagram of the extended state of the utility model;

[0016] Figure 4 This is a schematic diagram of the utility model in a retracted state;

[0017] Figure 5 This is a schematic diagram of the structure of the inner piston sleeve of the utility model;

[0018] Figure 6 This is a schematic diagram of the piston rod structure of the utility model.

[0019] In the figure, 1, cylinder barrel; 2, end cover; 3, lifting ring; 4, first oil port; 401, first cavity; 5, second oil port; 501, second cavity; 6, third oil port; 601, first aperture; 602, first oil hole; 603, second aperture; 604, second oil hole; 605, third aperture; 7, outer piston sleeve; 701, first sealing ring; 8, inner piston sleeve; 801, second sealing ring; 802, groove; 9, piston rod; 901, third oil hole; 902, fourth aperture; 903, fourth oil hole; 10, sealing block; 101, third sealing ring; 11, guide sleeve; 12, thread. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1 To Attachment Figure 6 The principles and features of the present invention are described, and the examples given are only used to explain the present invention, and are not used to limit the scope of the present invention.

[0021] A double-acting multi-stage piston cylinder includes a cylinder barrel 1, a piston rod 9 is arranged in the cylinder barrel 1, one end of the piston rod 9 is connected to an inner piston sleeve 8, and an outer piston sleeve 7 is arranged on the outer surface of the inner piston sleeve 8; the outer piston sleeve 7 can reciprocate along the two ends of the cylinder barrel 1, and the inner piston sleeve 8 can reciprocate along the two ends of the outer piston sleeve 7. A sealing block 10 is also arranged in the outer piston sleeve, and the sealing block 10 is connected to one end of the outer piston sleeve 7 away from the inner piston sleeve 8. The sealing block 10 moves with the outer piston sleeve 7; a first sealing ring 701 is arranged on the outer piston sleeve 7, and the first sealing ring 701 contacts the cylinder barrel 1; a second sealing ring 801 is arranged on the inner piston sleeve 8, and the second sealing ring 801 contacts the inner wall of the outer piston sleeve 7; a third sealing ring 101 is arranged in the sealing block 10, and the third sealing ring 101 contacts the piston rod 9.

[0022] An end cover 2 is provided at one end of the cylinder 1, and a guide sleeve 11 is provided at the other end of the cylinder 1. The guide sleeve 11 is used to limit the movement range of the outer piston sleeve 7. A lifting ring 3 is provided on the end cover 2. The surface of the cylinder 1 is provided with a first oil port 4, a second oil port 5, and a third oil port 6. A first cavity 401 is provided between the first oil port 4 and the outer piston sleeve 7, and a second cavity 501 is provided between the first cavity 401 and the second oil port 5. The first cavity 401 and the second cavity 501 are connected, and the first oil port 4 and the second oil port 5 are connected to each other. The hydraulic oil for extension enters from the first oil port 4, flows into the first cavity 401, and pushes out the outer piston sleeve 7 and the inner piston sleeve 8. The function of the second cavity 501 is to clean the oil in the first cavity 401 during the return stroke.

[0023] The outer piston sleeve 7 is provided with a first oil hole 602 and a second oil hole 604. The third oil port 6 is in communication with the first oil hole 602, a first hole 601 is provided between the third oil port 6 and the first oil hole 602, a second hole 603 is provided between the first oil hole 602 and the second oil hole 604, and a third hole 605 is provided between the second oil hole 604 and the inner piston sleeve 8. The hydraulic oil for the return stroke enters from the third oil port 6, flows into the first oil hole 602 through the first hole 601, flows into the second oil hole 604 from the first oil hole 602 through the second hole 603, and flows into the third hole 605 through the second oil hole 604 to contact the inner piston sleeve 8. When the return stroke hydraulic oil flows in, the return stroke hydraulic oil props up the third hole 605, the hydraulic oil in the first cavity 401 is sucked out from the second oil port 5 through the second cavity 501, and the third hole 605 expands to retract the outer piston sleeve 7 and the inner piston sleeve 8.

[0024] A third oil hole 901 and a fourth oil hole 903 are provided in the piston rod 9, and a fourth hole 902 is provided between the third oil hole 901 and the fourth oil hole 903. A thread 12 is provided at one end of the piston rod 9 close to the third oil hole 901, and a thread 12 is provided at one end inside the inner piston sleeve 8. The piston rod 9 is threadedly connected to the interior of the inner piston sleeve 8, and a groove 802 is provided at one end of the inner piston sleeve 8 away from the thread 12. The piston rod 9 is threadedly connected to the inner piston sleeve 8, and a fourth sealing ring is provided on the piston rod 9, and the height of the fourth sealing ring exceeds the height of the groove 802. When the oil in the hydraulic cylinder needs to be drained, the second oil port 5 and the third oil port 6 pump oil outward, but the third hole 605 and the second hole 603 are far away from the third oil port 6, and some oil may remain in the oil path, which may cause blockage of the oil path. At this time, the piston rod 9 is rotated out in the ejection direction, and the fourth sealing ring moves with the piston rod 9, causing the third oil hole 901 to leak out, and the oil flows into the fourth hole 902 along the third oil hole 901 and flows out from the fourth oil hole 903.

[0025] The specific implementation of this device is

[0026] When the hydraulic cylinder needs to extend, the hydraulic oil is injected into the first oil port 4, the second oil port 5 is closed, the hydraulic oil flows into the first cavity 401, the hydraulic oil pushes out the outer piston sleeve 7 and the inner piston sleeve 8, and the hydraulic oil is only in the first cavity 401 and the second cavity 501.

[0027] When the hydraulic cylinder needs to perform a return motion, the hydraulic oil is sucked out from the second oil port 5 and at the same time, the hydraulic oil is injected into the third oil port 6. The hydraulic oil enters the third hole 605 along the first hole 601 and the second hole 603, moves the outer piston sleeve 7 and the inner piston sleeve 8 in the return stroke, completely closes the first cavity 401, and the oil enters the second cavity 501 and is sucked away.

[0028] When the hydraulic cylinder needs to be emptied, the oil is sucked out from the third oil port 6. However, the third hole 605 and the second hole 603 are far away from the third oil port 6. Some oil may remain in the oil path, which may cause blockage of the oil path. At this time, the piston rod 9 is manually rotated out in the ejection direction to leak the third oil hole 901. The oil flows along the third oil hole 901 into the fourth hole 902 and flows out from the fourth oil hole 903.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A double-acting multi-stage piston cylinder, characterized in that: The invention comprises a cylinder (1), wherein a piston rod (9) is arranged inside the cylinder (1), one end of the piston rod (9) is connected to an inner piston sleeve (8), and an outer piston sleeve (7) is arranged outside the inner piston sleeve (8); a first oil port (4), a second oil port (5), and a third oil port (6) are provided on the surface of the cylinder (1), and the first oil port (4) and the second oil port (5) are connected to each other; the outer piston sleeve (7) is provided with a first oil hole (602), a second oil hole (603), and a third oil hole (604). (604), the hydraulic oil flows into the first oil hole (602) or flows out of the first oil hole (602) from the third oil port (6); the outer piston sleeve (7) can reciprocate along the two ends of the cylinder barrel (1) in the cylinder barrel (1), and the inner piston sleeve (8) can reciprocate along the two ends of the outer piston sleeve (7); the piston rod (9) is provided with a third oil hole (901) and a fourth oil hole (903); the hydraulic oil can flow out from the fourth oil hole (903).

2. The double-acting multi-stage piston cylinder according to claim 1, characterized in that: A first cavity (401) is provided between the first oil port (4) and the outer piston sleeve (7), a second cavity (501) is provided between the first cavity (401) and the second oil port (5), and the first cavity (401) and the second cavity (501) are communicated; a first hole path (601) is provided between the third oil port (6) and the first oil hole (602), a second hole path (603) is provided between the first oil hole (602) and the second oil hole (604), and a third hole path (605) is provided between the second oil hole (604) and the inner piston sleeve (8); a fourth hole path (902) is provided between the third oil hole (901) and the fourth oil hole (903).

3. The double-acting multi-stage piston cylinder according to claim 2, characterized in that: An end cover (2) is provided at one end of the cylinder barrel (1), and a guide sleeve (11) is provided at the other end of the cylinder barrel (1); a sealing block (10) is also provided inside the outer piston sleeve (7), and the sealing block (10) is connected to an end of the outer piston sleeve (7) away from the inner piston sleeve (8).

4. The double-acting multi-stage piston cylinder according to claim 3, characterized in that: A thread (12) is provided at one end of the piston rod (9) close to the third oil hole (901); a thread (12) is provided at one end inside the inner piston sleeve (8); and a groove (802) is provided at one end of the inner piston sleeve (8) away from the thread (12).

5. The double-acting multi-stage piston cylinder according to claim 4, characterized in that: The outer piston sleeve (7) is provided with a first sealing ring (701), and the first sealing ring (701) is in contact with the cylinder barrel (1); the inner piston sleeve (8) is provided with a second sealing ring (801), and the second sealing ring (801) is in contact with the inner wall of the outer piston sleeve (7); the sealing block (10) is provided with a third sealing ring (101), and the third sealing ring (101) is in contact with the piston rod (9); the piston rod (9) is provided with a fourth sealing ring, and the height of the fourth sealing ring exceeds the height of the groove (802).

6. The double-acting multi-stage piston cylinder according to claim 3, characterized in that: The end cover (2) is provided with a lifting ring (3), and the end of the piston rod (9) away from the cylinder barrel (1) is provided with a lifting ring (3).

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