Digital hydraulic cylinder with buffer structure

Abstract

The utility model relates to the technical field of digital hydraulic cylinders, and discloses a digital hydraulic cylinder with a buffer structure, which comprises a hydraulic cylinder, a screw rod, a piston, a piston rod and the like, a leather cup is sleeved on the outer surface of the piston rod in a sliding manner, the edge of the leather cup is in sliding contact with the side wall of an inner cavity of the hydraulic cylinder, a damping hole is formed in the leather cup, and the buffer structure is arranged in the damping hole. A limiting ring is fixedly welded to the position, located on the right side of the leather cup, of the side wall of an inner cavity of the hydraulic cylinder, and an air cavity is formed in the piston. When the piston rod on the digital hydraulic cylinder retracts, the lead screw is used for driving the piston and the piston rod to retract, and the contact area between the piston rod and hydraulic oil is increased through the leather cup on the outer side of the piston rod, so that the retraction speed of the piston rod can be buffered by the leather cup, and the hydraulic oil in the hydraulic cylinder can pass through the damping hole; the retraction speed of the piston rod is reduced, so that vibration generated when the piston rod retracts is buffered, and the stability of the piston rod is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of digital hydraulic cylinders, in particular to a digital hydraulic cylinder with a buffer structure. Background Art

[0002] The digital hydraulic cylinder has completely digital motion characteristics. The frequency of the electric pulse corresponds to the movement speed of the cylinder, and the number of electric pulses corresponds to the stroke of the cylinder. The digital hydraulic cylinder is a high-tech product that combines a stepper or servo motor, a hydraulic slide valve, and a closed-loop position feedback design inside the hydraulic cylinder and connects to the hydraulic oil source. All functions are directly transmitted through the digital pulse signal sent by the digital hydraulic cylinder controller or computer or programmable logic controller to complete the length vector control at different speeds.

[0003] During use, the existing digital hydraulic cylinder, especially when the piston rod retracts, is prone to vibration due to its fast oil return speed, which reduces the stability of the piston rod and affects the accuracy and sealing effect of the hydraulic cylinder. Utility Model Content

[0004] In view of the shortcomings of the existing digital hydraulic cylinders, the utility model provides a digital hydraulic cylinder with a buffer structure, which has the advantages of being able to buffer the vibration when the piston rod contracts and shorten the extension time of the piston rod, thus solving the technical problem of vibration generated when the piston rod retracts.

[0005] The utility model provides the following technical solution: a digital hydraulic cylinder with a buffer structure, comprising a hydraulic cylinder, and also comprising:

[0006] A flange is fixedly mounted on the left end surface of the hydraulic cylinder, an oil return integrated block is fixedly mounted in the middle of the left end surface of the flange, a servo motor is fixedly mounted in the middle of the left end surface of the oil return integrated block, a screw rod is fixedly connected to the output end of the servo motor, a piston is slidably connected to the inner cavity of the hydraulic cylinder, a sealing strip is fixedly sleeved on the outer surface of the piston, the outer surface of the sealing strip is in sliding contact with the side wall of the inner cavity of the hydraulic cylinder, a piston rod is fixedly mounted in the middle of the right end surface of the piston, a placement cavity is opened inside the piston rod, and an oil return pipe is fixedly connected between the outer surface of the hydraulic cylinder and the outer surface of the oil return integrated block.

[0007] Preferably, the piston rod comprises:

[0008] A leather cup is slidably sleeved on the outer surface of the piston rod, and the edge of the leather cup is in sliding contact with the side wall of the inner cavity of the hydraulic cylinder;

[0009] A damping hole is provided on the leather cup;

[0010] The limiting ring is fixedly connected to the inner cavity side wall of the hydraulic cylinder and is located on the right side of the leather cup.

[0011] Preferably, the piston comprises:

[0012] An air cavity is provided inside the piston;

[0013] A tension spring, fixedly connected to the middle of the left side of the air cavity and located at the outer ring of the screw rod;

[0014] A movable plate, fixedly connected to an end of the tension spring away from the piston;

[0015] A through hole is provided inside the side wall of the piston rod, and the through hole runs through the air cavity and the piston.

[0016] Preferably, the movable plate includes:

[0017] An air bag, fixedly connected to the middle of the end surface of the movable plate away from the tension spring;

[0018] A connecting rod, fixedly connected to the end surface of the movable plate facing the piston;

[0019] An air groove is provided inside the connecting rod, a left end opening of the air groove is communicated with the air bag, and a right end of the connecting rod extends into a through hole on the piston.

[0020] Preferably, when the piston rod is extended, the end of the connecting rod away from the movable plate is in the air cavity, and when the piston rod is retracted, the end of the connecting rod away from the movable plate is in the through hole on the right side of the air cavity.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] 1. By designing the leather cup, damping hole and limit ring, when the piston rod on the digital hydraulic cylinder retracts, the screw rod is used to drive the piston and the piston rod to retract. Since the leather cup on the outside of the piston rod increases the contact area between the piston rod and the hydraulic oil, the retraction speed of the piston rod will be buffered by the leather cup, and the hydraulic oil inside the hydraulic cylinder will pass through the damping hole. Since the retraction speed of the piston rod is slowed down, the vibration generated when the piston rod retracts is buffered, thereby improving the stability of the piston rod.

[0023] 2. By designing the air cavity, tension spring, movable plate, airbag and connecting rod, when the piston rod is extended, the movement of the piston will pull the tension spring and cause the airbag to stretch, so that the air port of the connecting rod is just in the air cavity. At this time, since the air cavity is connected to the through hole, the air on the outside of the hydraulic cylinder enters the airbag under the negative pressure of the airbag, and the gas entering the airbag will increase the pressure of the airbag. Since the airbag is inside the oil return integrated block, the pressure of the hydraulic oil inside the oil return integrated block is also increased, thereby accelerating the return of the hydraulic oil to the inside of the hydraulic cylinder. Secondly, when the piston rod retracts, the piston will squeeze the airbag during the retraction process, and at this time the connecting rod is in the through hole on the right side of the air cavity, so that the gas inside the airbag will slowly be discharged through the through hole. Therefore, the airbag will also buffer the speed of the piston rod retraction, further improving the stability of the piston rod retraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of the digital hydraulic cylinder of the utility model;

[0025] Figure 2 This is a schematic diagram of the internal structure of the digital hydraulic cylinder of the utility model;

[0026] Figure 3 This is a schematic diagram of the internal structure of the oil return integrated block of the utility model;

[0027] Figure 4 This is a schematic diagram of the internal structure of the piston of the utility model;

[0028] Figure 5 For this utility model Figure 4 Enlarged structural diagram at A in the middle.

[0029] In the figure: 1. hydraulic cylinder; 2. flange; 3. oil return integrated block; 4. servo motor; 5. screw rod; 6. piston; 61. air chamber; 62. tension spring; 63. movable plate; 64. air bag; 65. connecting rod; 66. air groove; 7. sealing strip; 8. piston rod; 81. leather cup; 82. damping hole; 83. limit ring; 84. through hole; 9. placement chamber; 10. oil return pipe. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] See also Figure 1-Figure 5A digital hydraulic cylinder with a buffer structure comprises a hydraulic cylinder 1, a flange 2 is fixedly mounted on the left end surface of the hydraulic cylinder 1, an oil return integrated block 3 is fixedly mounted in the middle of the left end surface of the flange 2, a servo motor 4 is fixedly mounted in the middle of the left end surface of the oil return integrated block 3, a screw rod 5 is fixedly welded on the output end of the servo motor 4, the screw rod 5 extends into the interior of the oil return integrated block 3 and the hydraulic cylinder 1, a piston 6 is slidably connected to the inner cavity of the hydraulic cylinder 1, the screw rod 5 is transmission sleeved with the piston 6, a sealing strip 7 is fixedly sleeved on the outer surface of the piston 6, the outer surface of the sealing strip 7 is in sliding contact with the side wall of the inner cavity of the hydraulic cylinder 1, a piston rod 8 is fixedly mounted in the middle of the right end surface of the piston 6, a placement cavity 9 is opened in the interior of the piston rod 8, the screw rod 5 extends into the interior of the placement cavity 9, and an oil return pipe 10 is fixedly connected between the outer surface of the hydraulic cylinder 1 and the outer surface of the oil return integrated block 3.

[0032] See also Figure 1-Figure 5 The outer surface of the piston rod 8 is slidably sleeved with a leather cup 81, and the edge of the leather cup 81 is in sliding contact with the inner cavity side wall of the hydraulic cylinder 1. The leather cup 81 and the damping hole 82 are used to buffer the speed of the piston rod 8 when it retracts. The leather cup 81 is provided with a damping hole 82, and a limiting ring 83 is fixedly welded on the right side of the leather cup 81 on the inner cavity side wall of the hydraulic cylinder 1 for limiting the leather cup 81.

[0033] See also Figure 1-Figure 5 An air cavity 61 is provided inside the piston 6 , and a tension spring 62 is fixedly welded to the outer ring of the screw rod 5 in the middle of the left side of the air cavity 61 , and a movable plate 63 is fixedly welded to the end of the tension spring 62 away from the piston 6 .

[0034] A through hole 84 is formed inside the side wall of the piston rod 8 . The through hole 84 penetrates the air cavity 61 and the piston 6 , so that the air outside the hydraulic cylinder 1 can enter the air cavity 61 .

[0035] See also Figure 1-Figure 5 An airbag 64 is fixedly connected to the middle part of the end surface of the movable plate 63 away from the tension spring 62, and a connecting rod 65 is fixedly welded to the end surface of the movable plate 63 facing the piston 6. An air groove 66 is opened inside the connecting rod 65, and the left end opening of the air groove 66 is connected to the airbag 64. The right end of the connecting rod 65 extends into the through hole 84 on the piston 6, ensuring that the negative pressure generated when the airbag 64 is stretched absorbs the air in the air cavity 61, so that the air enters the airbag 64, thereby increasing the hydraulic oil pressure in the oil return integrated block 3.

[0036] See also Figure 1-Figure 5 When the piston rod 8 is extended, the end of the connecting rod 65 away from the movable plate 63 is in the air cavity 61, and when the piston rod 8 is retracted, the end of the connecting rod 65 away from the movable plate 63 is in the through hole 84 on the right side of the air cavity 61, ensuring that when the airbag 64 is squeezed, the gas inside the airbag 64 will slowly be discharged through the air groove 66 and the through hole 84, thereby buffering the retraction of the piston rod 8.

[0037] Working principle: When the hydraulic cylinder 1 needs to extend or retract, the servo motor 4 is turned on, the servo motor 4 drives the screw rod 5 to rotate, the screw rod 5 drives the piston 6 to move, and the piston 6 drives the piston rod 8 to move, thereby completing the extension or retraction of the piston rod 8. When the piston rod 8 is in the retraction process, the design of the leather cup 81 and the damping hole 82 is utilized so that the hydraulic oil inside the hydraulic cylinder 1 passes through the damping hole 82, thereby slowing down the retraction speed of the piston rod 8, so that the leather cup 81 and the damping hole 82 are utilized to buffer the retraction of the piston rod 8 to avoid vibration when the piston rod 8 retracts. When the piston rod 8 is in the extension process, the movement of the piston 6 drives the tension spring 62 to stretch, so that the air port of the air groove 66 in the connecting rod 65 is just in the air cavity 61. At this time, the tension spring 6 2 will also stretch the airbag 64, so that negative pressure is generated inside the airbag 64. The negative pressure of the airbag 64 is used to force the air outside the hydraulic cylinder 1 to enter the airbag 64, thereby increasing the pressure of the airbag 64. Similarly, as the pressure of the airbag 64 increases, the hydraulic oil pressure inside the oil return integrated block 3 will also increase, so that the speed at which the hydraulic oil enters the hydraulic cylinder 1 increases. When the piston rod 8 is in the retraction process, the piston 6 will squeeze the airbag 64, and at this time, the air port of the air groove 66 in the connecting rod 65 is in the through hole 84 on the right side of the air cavity 61. At this time, the exhaust speed of the airbag 64 when being squeezed will slow down, so the retraction process of the airbag 64 will slow down, thereby indirectly buffering the retraction of the piston rod 8, and further improving the stability of the piston rod 8 when retracting.

Claims

1. A digital hydraulic cylinder with a buffer structure, comprising a hydraulic cylinder (1), characterized in that: Also includes: A flange (2) is fixedly mounted on the left end surface of the hydraulic cylinder (1); an oil return integrated block (3) is fixedly mounted in the middle of the left end surface of the flange (2); a servo motor (4) is fixedly mounted in the middle of the left end surface of the oil return integrated block (3); a screw rod (5) is fixedly connected to the output end of the servo motor (4); a piston (6) is slidably connected to the inner cavity of the hydraulic cylinder (1); a sealing strip (7) is fixedly sleeved on the outer surface of the piston (6); the outer surface of the sealing strip (7) is in sliding contact with the side wall of the inner cavity of the hydraulic cylinder (1); a piston rod (8) is fixedly mounted in the middle of the right end surface of the piston (6); a placement cavity (9) is provided inside the piston rod (8); and an oil return pipe (10) is fixedly connected between the outer surface of the hydraulic cylinder (1) and the outer surface of the oil return integrated block (3); The piston rod (8) comprises: A leather cup (81) is slidably sleeved on the outer surface of the piston rod (8), and the edge of the leather cup (81) is in sliding contact with the side wall of the inner cavity of the hydraulic cylinder (1); A damping hole (82) is provided on the leather cup (81); The limiting ring (83) is fixedly connected to the inner cavity side wall of the hydraulic cylinder (1) and is located on the right side of the leather cup (81).

2. A digital hydraulic cylinder with a buffer structure according to claim 1, characterized in that: The piston (6) comprises: An air cavity (61) is provided inside the piston (6); A tension spring (62) fixedly connected to the middle of the left side of the air cavity (61) and located on the outer ring of the screw rod (5); A movable plate (63) fixedly connected to an end of the tension spring (62) away from the piston (6); A through hole (84) is provided inside the side wall of the piston rod (8), and the through hole (84) passes through the air cavity (61) and the piston (6).

3. A digital hydraulic cylinder with a buffer structure according to claim 2, characterized in that: The movable plate (63) comprises: An air bag (64) fixedly connected to the middle portion of the end surface of the movable plate (63) away from the tension spring (62); A connecting rod (65) fixedly connected to an end surface of the movable plate (63) facing the piston (6); The air groove (66) is provided inside the connecting rod (65), the left end opening of the air groove (66) is communicated with the air bag (64), and the right end of the connecting rod (65) extends into the through hole (84) on the piston (6).

4. A digital hydraulic cylinder with a buffer structure according to claim 3, characterized in that: When the piston rod (8) is extended, the end of the connecting rod (65) away from the movable plate (63) is located in the air cavity (61); when the piston rod (8) is retracted, the end of the connecting rod (65) away from the movable plate (63) is located in the through hole (84) on the right side of the air cavity (61).

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