CN116379039A

CN116379039A - Double-stroke limiting hydraulic cylinder

Info

Publication number: CN116379039A
Application number: CN202310504840.0A
Authority: CN
Inventors: 沈子勋; 沈彬
Original assignee: Wuxi Yiyuan Hydraulic Machinery Co ltd
Current assignee: Wuxi Yiyuan Hydraulic Machinery Co ltd
Priority date: 2023-05-06
Filing date: 2023-05-06
Publication date: 2023-07-04
Anticipated expiration: 2043-05-06
Also published as: CN116379039B

Abstract

The invention belongs to the technical field of hydraulic cylinders, in particular to a double-stroke limiting hydraulic cylinder which comprises a cylinder head unit, a cylinder tail unit and a cylinder barrel; when the first oil way is used for oil feeding, the blades are used for realizing the rotation of the blades, the blades are used for rotating to drive the coaxial supporting rods to rotate, and then the ball nut support is driven to adjust the position, because the length of the threads is effective, when a large amount of oil is fed, the ball nut support can only be moved from one end to the other end, the distance between the ball nut support which is moved to the other end and the interfaces of the first cavity and the second cavity is added with the length of the first cavity to be the adjusted piston rod stroke, the oil is discharged from the second oil way, the oil stored in the first cavity and the second cavity is gathered at the second oil way, the blades are driven to rotate by the oil in the second cavity, and the blades keep the same rotation direction as the oil fed from the first oil way, and the ball nut support can not generate position change any more because of limited length of the threads.

Description

Double-stroke limiting hydraulic cylinder

Technical Field

The invention belongs to the technical field of hydraulic cylinders, and particularly relates to a double-stroke limiting hydraulic cylinder.

Background

The hydraulic cylinder is an executive component capable of converting hydraulic energy into mechanical energy, and can do linear reciprocating and swinging motion through structural design; the stroke of the hydraulic cylinder mainly refers to the position difference between the full extension and the full retraction of the piston rod, and the stroke of the hydraulic cylinder is generally fixed, however, in some specific implementation environments, the hydraulic cylinder is required to provide a multi-stroke function;

the double-stroke hydraulic cylinder can be understood as a multi-stroke hydraulic cylinder, multiple strokes can be provided for meeting special implementation environments, for example, patent No. CN211852353U discloses a stroke-adjustable hydraulic cylinder device, which comprises a hydraulic cylinder barrel, a hydraulic cylinder rod, a piston, a rod cavity cylinder cover and a rod-free cavity tail gland, wherein the rod cavity cylinder cover and the rod-free cavity tail gland are respectively fixed at two ends of the hydraulic cylinder barrel through fastening bolts.

However, in the prior art, the gasket is adopted to adjust the stroke of the hydraulic cylinder, the hydraulic cylinder is required to be stopped, the oil way is cut off, the hydraulic cylinder is disassembled, and the gasket is additionally arranged, so that when dust or impurities exist between the surfaces of the gasket or between the adjacent surfaces of the gasket and the gasket, the adjustment of the stroke of the hydraulic cylinder can be directly influenced, the error occurs in the stroke of the hydraulic cylinder after the adjustment, and the gasket is easy to have serious influence when the gasket is applied to the field with high-precision requirements; in addition, in the prior art, the stroke adjustment is generally realized by adjusting the position of the hydraulic cylinder, and the position of the hydraulic cylinder cannot be accurately adjusted in the mode, so that serious influence still occurs when the hydraulic cylinder is applied to the field with high precision requirements.

Therefore, the invention provides the double-stroke limiting hydraulic cylinder.

Disclosure of Invention

In order to overcome the deficiencies of the prior art, at least one technical problem presented in the background art is solved.

The technical scheme adopted for solving the technical problems is as follows: the invention relates to a double-stroke limiting hydraulic cylinder which comprises a cylinder head unit, a cylinder tail unit and a cylinder barrel; the cylinder head unit and the cylinder tail unit are respectively fixedly connected at two ends of the cylinder barrel through bolts; a piston is movably connected in the cylinder barrel, and a piston rod is connected in the center of the piston in a penetrating manner; one end of the piston rod, which is away from the piston, penetrates through the cylinder head unit;

the top of one end of the cylinder barrel is communicated with a third oil way, and the bottom of the other end of the cylinder barrel is communicated with a second oil way; the cylinder tail unit is communicated with the second oil way in parallel with a first oil way; a stroke adjusting unit is arranged in the cylinder tail unit and is used for changing the stroke of the hydraulic cylinder; and the cylinder tail unit is axially and rotatably connected with a propping rod, and the propping rod is propped against the other end of the piston.

Preferably, the cylinder tail unit comprises a cylinder bottom cover and a cylinder tail; the cylinder bottom cover is fixedly connected with the cylinder tail part through bolts; the stroke adjusting unit comprises a supporting rod; the supporting rod is rotationally connected with the center of the cylinder bottom cover and penetrates through the tail part of the cylinder; the bearing is embedded and connected at one side of the cylinder tail part facing the cylinder bottom cover, and the middle part of the supporting rod penetrates through the bearing; the cylinder tail is connected with a first guide sleeve in an embedded mode towards one side of the cylinder barrel, and the abutting head penetrates through the first guide sleeve.

Preferably, a second cavity is formed in the tail part of the cylinder, and the supporting rod is movably connected in the second cavity; the second cavity is communicated with the first cavity in the cylinder barrel; the middle part of the supporting rod is provided with threads, and ball nut supports are matched with the threads.

Preferably, the bottom of the tail part of the cylinder is communicated with a first oil way, and the first oil way is communicated with the second cavity; the tail part of the supporting rod is fixedly connected with a blade; the blade corresponds to the inner outlet of the first oil way.

Preferably, flanges are arranged at two ends of the cylinder barrel, and the cylinder barrel is fixedly connected with the cylinder head unit and the cylinder tail unit through bolts penetrating through the flanges; the cylinder tail unit comprises a cylinder top cover and a cylinder head; a second guide sleeve is embedded and connected at one side of the cylinder top cover, which is away from the cylinder barrel; the piston rod penetrates through the second guide sleeve.

Preferably, a contact cavity is formed at one end of the piston rod, which faces the tail part of the cylinder, and the supporting rod is in sliding fit with the contact cavity; the inner bottom surface of the contact cavity is fixedly connected with a spring, and the stroke end of the spring is fixedly connected with a contact plate; the contact plate is connected to the inner wall of the contact cavity in a sliding way, and a positioning groove corresponding to the supporting rod is formed in one side, facing the tail part of the cylinder, of the contact plate.

Preferably, the piston rod is in sliding fit with an alignment unit, and the alignment unit comprises a sheath; a plurality of grooves are formed in the inner side of the sheath, and swing arms are hinged in the grooves; one end of the swing arm is hinged in the groove, and the other end of the swing arm is rotationally connected with a roller; the roller is in rolling fit with the outer wall of the piston rod.

Preferably, a plurality of movable grooves are formed in the middle of the outer wall of the sheath, and the plurality of movable grooves are arranged in a circumferential array mode; the movable groove is internally connected with a ball in a rolling way, and the ball is made of ceramic materials.

Preferably, the outer wall of the piston is sleeved with a plurality of O-shaped sealing rings; o-shaped sealing rings are correspondingly arranged between the cylinder bottom cover and the cylinder tail, and O-shaped sealing rings are correspondingly arranged between the cylinder top cover and the cylinder head.

Preferably, one end of the tail part of the cylinder facing the cylinder barrel is fixedly connected with a mounting plate through a bolt, and the mounting plate is positioned at the joint of the second cavity and the first cavity; the supporting rod penetrates through the middle of the mounting plate; the ball nut support is located one side of mounting panel towards the cylinder, and the paddle is located one side of mounting panel towards the jar afterbody.

The beneficial effects of the invention are as follows:

1. according to the double-stroke limiting hydraulic cylinder, the first oil way, the second oil way and the third oil way are arranged, oil is fed into the first oil way, the second oil way is matched with the third oil way to feed oil, the paddles are driven to rotate by the oil when the first oil way feeds oil, the coaxial abutting rods are driven to rotate by the rotation of the paddles, the positions of the ball nut supports are further driven to be adjusted, the length of the threads is effective, when a large amount of oil is fed, only one end of the threads is enabled to move to the other end of the threads, the distance between the ball nut supports which move to the other end of the threads and the interface of the first cavity and the second cavity is increased by the length of the first cavity, the stroke of the piston rod is adjusted, the second oil way feeds oil, the oil stored in the first cavity and the second cavity is collected at the second oil way, the paddles are driven to rotate by the oil in the second cavity, the paddles keep the same rotation direction as the oil fed by the first oil way, and the ball nut supports cannot stretch again due to the limited length of the threads, and the double-stroke effect of the piston rod is achieved.

2. According to the double-stroke limiting hydraulic cylinder, the ball nut support is arranged, the ball nut support is used for limiting the stroke of the piston rod which is completely retracted, and the supporting rod is arranged in the middle of the ball nut support, so that the piston rod is prevented from being influenced by the supporting rod, and the buffering effect when the piston rod is retracted is compensated.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is a perspective view of a first embodiment of the present invention;

FIG. 2 is a first partially cut-away perspective view of a first embodiment of the invention;

FIG. 3 is a second partial cutaway perspective view of a first embodiment of the present invention;

FIG. 4 is a partially cut-away exploded perspective view of a first embodiment of the present invention;

FIG. 5 is a perspective view, partially in section, of a tail unit of a first embodiment of the present invention;

FIG. 6 is a perspective view of a blade, ball nut mount and abutment in combination according to a first embodiment of the invention;

FIG. 7 is a perspective view showing a combination of a piston rod and an alignment unit according to a first embodiment of the present invention;

fig. 8 is a perspective view of a piston rod and a cylinder head unit in a second embodiment of the present invention;

in the figure: 1. a cylinder bottom cover; 11. a cylinder tail; 12. a bearing; 13. a first guide sleeve; 14. a second cavity; 15. a mounting plate; 2. a cylinder; 21. a first cavity; 31. a first oil passage; 32. a second oil path; 33. a third oil passage; 4. a cylinder top cover; 41. a cylinder head; 42. a second guide sleeve; 43. a screw; 5. a piston rod; 51. a piston; 52. a contact cavity; 53. a spring; 54. a contact plate; 61. a supporting rod; 62. a ball nut support; 63. a paddle; 7. a sheath; 71. swing arms; 72. a roller; 73. a ball;

Detailed Description

The invention is further described in connection with the following detailed description in order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the invention easy to understand.

Example 1

As shown in fig. 1 to 3, in order to solve the problem of precision caused by the fact that in the prior art, when the hydraulic cylinder stroke requirement is changed, the hydraulic cylinder stroke is changed by adding a gasket or adjusting the position of the hydraulic cylinder; the embodiment of the invention discloses a double-stroke limiting hydraulic cylinder which comprises a cylinder head unit, a cylinder tail unit and a cylinder barrel 2; the cylinder head unit and the cylinder tail unit are respectively fixedly connected with two ends of the cylinder barrel 2 through bolts; a piston 51 is movably connected in the cylinder barrel 2, and a piston rod 5 is connected in the center of the piston 51 in a penetrating manner; one end of the piston rod 5, which is away from the piston 51, penetrates the cylinder head unit; the general hydraulic cylinder is provided with a cylinder cover, a cylinder bottom and a cylinder barrel 2, and corresponds to the cylinder head unit, the cylinder tail unit and the cylinder barrel 2 respectively, when the hydraulic cylinder is used, the piston 51 is extruded by oil liquid, pressure is generated, the piston rod 5 is driven to slide in the cylinder barrel 2, and the functions of extending and contracting the piston rod 5 are realized.

A third oil way 33 is communicated with the top of one end of the cylinder barrel 2, and a second oil way 32 is communicated with the bottom of the other end of the cylinder barrel 2; the cylinder tail unit is communicated with a first oil way 31 in parallel with a second oil way 32; a stroke adjusting unit is arranged in the cylinder tail unit and is used for changing the stroke of the hydraulic cylinder; the cylinder tail unit is axially and rotatably connected with a supporting rod 61, and the supporting rod 61 and the piston 51 are concentrically arranged; as described above, the hydraulic cylinder oil is adjusted by the first oil path 31, the second oil path 32 and the third oil path 33, wherein when the stroke does not need to be adjusted, the effect of extending and contracting the piston rod 5 can be achieved by adopting the oil inlet and outlet of the second oil path 32 and the oil outlet of the third oil path 33, and when the stroke of the piston rod 5 needs to be adjusted, the extending and contracting function of the piston rod 5 is achieved by adopting the oil inlet of the first oil path 31 and the oil outlet of the second oil path 32 and the oil inlet liquid outlet of the third oil path 33, wherein the stroke adjusting unit changes the maximum stroke of the piston rod 5 which allows contraction, so that when the piston rod 5 is driven to extend by supplying oil, the difference between the complete extending and the complete contracting of the piston rod 5 is changed, thereby realizing the adjustment of the stroke of the hydraulic cylinder, and the double-stroke adjustment.

As shown in fig. 2-4, the cylinder tail unit comprises a cylinder bottom cover 1 and a cylinder tail 11; the cylinder bottom cover 1 is fixedly connected with the cylinder tail 11 through bolts; the stroke adjustment unit includes a lever 61; the supporting rod 61 is rotationally connected with the center of the cylinder bottom cover 1, and the supporting rod 61 penetrates through the cylinder tail 11; the abutting rod 61 is matched with the tail of the piston rod 5, and when the piston rod 5 is contracted, the tail of the piston rod is in sliding fit with the abutting rod 61; the bearing 12 is embedded and connected to one side of the cylinder tail 11 facing the cylinder bottom cover 1, and the middle part of the supporting rod 61 penetrates through the bearing 12; the bearing 12 is used as a mechanical element, so that sliding friction between the shaft and the shaft seat can be converted into rolling friction, the friction coefficient is reduced, and the smoothness of rotation of the supporting rod 61 is improved; a first guide sleeve 13 is embedded and connected to one side of the cylinder tail 11 facing the cylinder barrel 2, and the head of the supporting rod 61 penetrates through the first guide sleeve 13; the first guide sleeve 13 is provided to restrict the rotation of the abutment rod 61 to be coaxial with the cylinder 2, and the stable rotation of the abutment rod 61 is the basis for restricting the contraction axial balance of the piston rod 5.

As shown in fig. 5, the cylinder tail 11 is provided with a second cavity 14, and the supporting rod 61 is movably connected in the second cavity 14; the second cavity 14 is communicated with the first cavity 21 inside the cylinder barrel 2; the second cavity 14 is communicated with the first cavity 21, and can be used as a basis for prolonging the stroke of the first cavity 21 in the cylinder barrel 2, when the stroke of the hydraulic cylinder is regulated, the length of the first cavity 21 is used as a first stroke, and the total length of the first cavity 21 and the second cavity 14 is used as a second stroke, so that the double-stroke regulation of the hydraulic cylinder is realized; the middle part of the supporting rod 61 is provided with a thread, and a ball nut support 62 is matched with the thread; the ball nut support 62 is in threaded fit with the support rod 61, and can drive the ball nut support 62 to horizontally slide in the middle of the support rod 61 when the support rod 61 rotates, the ball nut support 62 is used for limiting the travel of the piston rod 5 when retracting, the initial position of the ball nut support 62 is at the interface between the first cavity 21 and the second cavity 14, the travel of the piston rod 5 is equal to the length of the first cavity 21, when the ball nut support 62 moves in the direction away from the piston rod 5, the travel of the piston rod 5 is specifically equal to the sum of the length of the first cavity 21, the sum of the spacing between the interface between the second cavity 14 and the side surface of the ball nut support 62, and the joint between the tail of the piston rod 5 and the side wall of the ball nut support 62 is the limit position of the retraction of the piston rod 5.

As shown in fig. 4 to 5, the bottom of the cylinder tail 11 is communicated with a first oil path 31, and the first oil path 31 is communicated with the second cavity 14; the tail part of the supporting rod 61 is fixedly connected with a paddle 63; the paddle 63 corresponds to the inner outlet of the first oil passage 31; when oil is fed into the cylinder barrel 2 by utilizing the first oil way 31, the fed oil acts on the paddles 63, different pressures are generated on the upper and lower surfaces of the paddles 63 by the oil due to the curvature of the paddles 63, the paddles 63 are promoted to rotate, and when the paddles 63 rotate, the coaxial supporting rod 61 can be driven to rotate, so that the ball nut support 62 can horizontally slide in the middle of the supporting rod 61 until the ball nut support 62 slides to the tail end of a thread, and the position of the ball nut support 62 is adjusted, namely the stroke of the piston rod 5 in retraction is adjusted; accordingly, when the piston rod 5 is retracted, oil is not discharged through the first oil passage 31, and oil is required to be discharged through the second oil passage 32, at this time, the oil is not recovered through the first oil passage 31, that is, pressure is not generated on the upper and lower blades of the vane 63, and the oil in the second chamber 14 is recovered through the second oil passage 32, and even if pressure is generated on the blades of the vane 63, the vanes can only be driven to rotate in the same rotational direction as the oil fed through the first oil passage 31, and the ball nut support 62 is not slid again when adjusted to the limit position due to the limited screw length, so that the stroke of the hydraulic cylinder after adjustment is not changed, thereby achieving the locking effect.

As shown in fig. 1 to 3, flanges are arranged at two ends of the cylinder barrel 2, and the cylinder barrel 2 is fixedly connected with the cylinder head unit and the cylinder tail unit through bolts penetrating the flanges; the cylinder tail unit comprises a cylinder top cover 4 and a cylinder head 41; a second guide sleeve 42 is connected to one side of the cylinder top cover 4 away from the cylinder barrel 2 in an embedded manner; the piston rod 5 penetrates through the second guide sleeve 42; flanges are arranged at two ends of the cylinder barrel 2, and can be connected with the cylinder head unit and the cylinder tail unit through bolts, so that the complexity of production and assembly is reduced, and meanwhile, the second guide sleeve 42 can keep telescopic axial balance of the piston rod 5.

As shown in fig. 5, a contact cavity 52 is formed at one end of the piston rod 5 facing the cylinder tail 11, and the inner diameter of the contact cavity 52 is larger than the outer diameter of the abutment rod 61; a spring 53 is fixedly connected to the inner bottom surface of the contact cavity 52, and a contact plate 54 is fixedly connected to one end of the spring 53 facing the supporting rod 61; the contact plate 54 is slidably connected to the inner wall of the contact cavity 52, and a positioning groove corresponding to the abutment rod 61 is formed on one side of the contact plate 54 facing the cylinder tail 11; in the prior art, there is the buffer sleeve in cylinder bottom cover 1 for with the afterbody contact of piston rod 5, when piston rod 5 is retracted fast, play the cushioning effect, because in this scheme, with the stroke that ball nut support 62 restriction piston rod 5 was retracted completely, and ball nut support 62 middle part is equipped with butt pole 61, consequently, in order to avoid piston rod 5 to retract and receive butt pole 61 influence, and in order to compensate the cushioning effect when piston rod 5 is retracted, the butt pole 61 that concentric setting gradually is close with piston rod 5, and in the contact chamber 52 of piston rod 5 afterbody, then butt pole 61 contacts contact plate 54, through the contact plate 54 in the extrusion contact chamber 52, make spring 53 take place extrusion deformation, realize the cushioning effect when retracting to piston rod 5, and can not influence the stroke of retracting of piston rod 5 because of butt pole 61's existence.

As shown in fig. 7, the piston rod 5 is slidably fitted with an alignment unit, and the alignment unit includes a sheath 7; a plurality of grooves are formed in the inner side of the sheath 7, and swing arms 71 are hinged in the grooves; one end of the swing arm 71 is hinged in the groove, and the other end of the swing arm 71 is rotatably connected with a roller 72; the roller 72 is in rolling fit with the outer wall of the piston rod 5; in a few cases, when the piston rod 5 is extended due to overlarge load, the piston rod 5 moves away from the central axis of the cylinder barrel 2, so that in subsequent use, the problem of the reduction of the precision of the hydraulic cylinder occurs, in order to avoid the problem, an alignment unit is arranged in the cylinder barrel 2, in the extending or retracting process of the piston rod 5, the roller 72 contacts the outer wall of the piston rod 5 to achieve the purposes of guiding and correcting, and meanwhile, a torsion spring coaxially arranged is arranged between the swing arm 71 and the groove, so that the piston rod 5 can be used for extending or retracting to generate guiding in different directions, and thus the load occurring in different directions is buffered and absorbed.

As shown in fig. 7, a plurality of movable grooves are formed in the middle of the outer wall of the sheath 7, and are arranged in a circumferential array manner; the movable groove is internally and rotatably connected with a ball 73, and the ball 73 is made of ceramic material; the position of the sheath 7 is not fixed, and therefore, the balls 73 are arranged on the sheath 7, so that the sheath 7 can freely slide on the inner wall of the cylinder barrel 2 to generate axial displacement, and the axial displacement is suitable for the telescopic effect of the piston rod 5 depending on the balls 73.

As shown in fig. 2 to 3, the outer wall of the piston 51 is sleeved with a plurality of O-shaped sealing rings; o-shaped sealing rings are correspondingly arranged between the cylinder bottom cover 1 and the cylinder tail 11, and O-shaped sealing rings are correspondingly arranged between the cylinder top cover 4 and the cylinder head 41; the O-shaped sealing ring plays a sealing effect, prevents that the pressure in the cylinder barrel 2 from being insufficient due to air inlet in the cylinder barrel 2 during operation, and cannot generate enough bearing effect.

As shown in fig. 2, an end of the cylinder tail 11 facing the cylinder barrel 2 is fixedly connected with a mounting plate 15 through bolts, and the mounting plate 15 is positioned at the junction of the second cavity 14 and the first cavity 21; the supporting rod 61 penetrates through the middle of the mounting plate 15; the ball nut support 62 is positioned on the side of the mounting plate 15 facing the cylinder barrel 2, and the blade 63 is positioned on the side of the mounting plate 15 facing the cylinder tail 11; the mounting plate 15 is arranged to facilitate the mounting of the blade 63 and the abutment bar 61.

Example two

As shown in fig. 8, in order to prevent the speed of the piston rod 5 when extending or retracting, to avoid the falling effect caused by insufficient pressure of the hydraulic oil path, a certain damping effect is given to the head of the piston rod 5, so as to achieve the deceleration effect when the piston rod 5 falls freely, in the first embodiment, another embodiment of the present invention is as follows: a screw 43 is vertically screwed on the outer wall of the second guide sleeve 42, and a supporting block is fixedly connected to the bottom of the screw 43 through a rigid spring; the screw rods 43 are arranged in a plurality along the circumferential array of the outer wall of the second guide sleeve 42; the mode of manually screwing the screw rod 43 is adopted, the acting force of the abutting block and the piston rod 5 is adjusted, and the abutting block is arranged to give the piston rod 5 axial friction force, so that the damping effect on the freely falling piston rod 5 is achieved under the condition that an oil way fails, the speed reduction effect on the piston rod 5 is achieved, the screw rod 43 can be reversely screwed out under the unnecessary condition, and the friction force applied to the piston rod 5 is cancelled.

Working principle: in the prior art, a gasket is adopted to adjust the stroke of the hydraulic cylinder, the hydraulic cylinder is required to be stopped, an oil way is cut off, the hydraulic cylinder is disassembled, and then the gasket is added, so that when the surface of the gasket or a plurality of gaskets are combined, if dust or impurities exist between adjacent surfaces of the gasket, the adjustment of the stroke of the hydraulic cylinder can be directly influenced, the error occurs in the stroke of the hydraulic cylinder after the adjustment, and the serious influence is easy to occur when the gasket is applied to the field with high-precision requirements; in addition, in the prior art, the stroke adjustment is generally realized by adjusting the position of the hydraulic cylinder, and the mode can not accurately adjust the position of the hydraulic cylinder, so that serious influence can still be generated when the method is applied to the field with high precision requirements; meanwhile, in the prior art, springs with different rigidities are arranged in the cylinder barrel 2 by utilizing the multi-layer sleeves, and the length of the piston rod 5 is adjusted under the action of oil extrusion, however, based on the related art, the pressure of the oil fed into the cylinder barrel 2 is only related to the load born by the piston rod 5, in other words, the multi-layer sleeves are only fully unfolded under the condition that the oil provides enough pressure, and the unfolding mode of the multi-layer sleeves cannot be controlled by the pressure of the oil fed into the cylinder barrel;

when the device is used, the first oil way 31, the second oil way 32 and the third oil way 33 are used for respectively feeding oil to realize the adjustment of the stroke of the piston rod 5, specifically, the initial position of the ball nut support 62 is arranged at the interface between the first cavity 21 and the second cavity 14, at this time, the length of the first cavity 21 corresponds to the stroke of the piston rod 5, meanwhile, the oil is fed through the second oil way 32 at this stage, the adjustment of the extension and retraction of the piston rod 5 is realized through feeding oil through the third oil way 33, when the stroke of the piston rod 5 needs to be increased or adjusted, the oil is fed through the first oil way 31, the second oil way 32 is matched with the third oil way 33, namely, when the first oil way 31 feeds oil, the rotation of the blade 63 is realized by utilizing the oil, the rotation of the blade 63, the rotation of the supporting rod 61 of the coaxial supporting rod 61 is driven, the middle thread of the supporting rod 61 is synchronously matched with the ball nut support 62, the position of the ball nut support 62 is driven, when a large amount of oil is fed, only one end of the ball nut support 62 is moved to the other end, and therefore, the distance between the ball nut support 62 moving to the other end and the other end is enabled when the first oil is fed, the first oil is required to be increased or the stroke is not increased, and the first oil is required to be rotated, and the first oil is required to be fed through the first oil way 32, and the rotation of the first oil way 32 is kept in the first oil way 32, and the same position is required to be rotated, and the first oil way is kept in the cavity 14, and the axial position is kept at the position is required to be the first cavity, and the first oil way is changed, and the position is required to be rotated, and the axial position is kept by the first oil is 32, and the axial position is can is rotated, and the speed is can and can is rotated and has the speed and is can and, the first oil way 31 is adopted to feed and discharge oil and the third oil way 33 is matched to feed oil, so that the oil can move reversely, the paddle 63 can rotate reversely, and the ball nut support 62 is reset to the initial position;

besides, there is a buffer sleeve in the cylinder bottom cover 1 for contacting with the tail of the piston rod 5, when the piston rod 5 is retracted rapidly, a buffer effect is achieved, because in this scheme, the ball nut support 62 limits the completely retracted stroke of the piston rod 5, and the middle of the ball nut support 62 is provided with the supporting rod 61, so in order to avoid the influence of the supporting rod 61 on the retraction of the piston rod 5, and in order to compensate the buffer effect when the piston rod 5 is retracted, the supporting rod 61 is gradually close to the piston rod 5 and enters into the contact cavity 52 at the tail of the piston rod 5, then the supporting rod 61 contacts with the contact plate 54, the spring 53 is deformed by pressing the contact plate 54 in the contact cavity 52, so that the buffer effect when the piston rod 5 is retracted is achieved, and the retraction stroke of the piston rod 5 is not affected by the existence of the supporting rod 61; meanwhile, under the rare condition, when the piston rod 5 is extended due to overlarge load, the piston rod 5 moves away from the central axis of the cylinder barrel 2, so that the problem of the decline of the precision of the hydraulic cylinder occurs in the subsequent use, in order to avoid the problem, an alignment unit is arranged in the cylinder barrel 2, in the extending or retracting process of the piston rod 5, the roller 72 contacts the outer wall of the piston rod 5, the guiding and correcting purposes are achieved, and meanwhile, a torsion spring which is coaxially arranged is arranged between the swing arm 71 and the groove, and the piston rod 5 can be used for extending or retracting, so that guiding in different directions is generated, and the device has certain applicability.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a spacing pneumatic cylinder of double stroke which characterized in that: comprises a cylinder head unit, a cylinder tail unit and a cylinder barrel (2); the cylinder head unit and the cylinder tail unit are respectively fixedly connected with two ends of the cylinder barrel (2) through bolts; a piston (51) is movably connected in the cylinder barrel (2), and a piston rod (5) is connected in the center of the piston (51) in a penetrating manner; one end of the piston rod (5) deviating from the piston (51) penetrates through the cylinder head unit;

a third oil way (33) is communicated with the top of one end of the cylinder barrel (2), and a second oil way (32) is communicated with the bottom of the other end of the cylinder barrel (2); a first oil way (31) is communicated with the second oil way (32) in parallel on the cylinder tail unit; a stroke adjusting unit is arranged in the cylinder tail unit and is used for changing the stroke of the hydraulic cylinder; an abutting rod (61) is axially and rotatably connected in the cylinder tail unit, and the abutting rod (61) abuts against the other end of the piston (51).

2. The double stroke limit hydraulic cylinder as claimed in claim 1 wherein: the cylinder tail unit comprises a cylinder bottom cover (1) and a cylinder tail (11); the cylinder bottom cover (1) is fixedly connected with the cylinder tail (11) through bolts; the stroke adjustment unit comprises a support rod (61); the supporting rod (61) is rotationally connected with the center of the cylinder bottom cover (1), and the supporting rod (61) penetrates through the cylinder tail (11); a bearing (12) is embedded and connected at one side of the cylinder tail (11) facing the cylinder bottom cover (1), and the middle part of the supporting rod (61) penetrates through the bearing (12); the cylinder tail (11) is connected with a first guide sleeve (13) in an embedded mode towards one side of the cylinder barrel (2), and the head of the supporting rod (61) penetrates through the first guide sleeve (13).

3. A double stroke limiting hydraulic cylinder as claimed in claim 2 wherein: a second cavity (14) is formed in the cylinder tail (11), and a supporting rod (61) is movably connected in the second cavity (14); the second cavity (14) is communicated with the first cavity (21) in the cylinder barrel (2); the middle part of the supporting rod (61) is provided with threads, and ball nut supports (62) are matched with the threads in a threaded mode.

4. A two-stroke limit cylinder as claimed in claim 3 wherein: the bottom of the cylinder tail part (11) is communicated with a first oil way (31), and the first oil way (31) is communicated with the second cavity (14); the tail part of the supporting rod (61) is fixedly connected with a paddle (63); the blade (63) corresponds to the inner outlet of the first oil passage (31).

5. The double stroke limit hydraulic cylinder as claimed in claim 4 wherein: flanges are arranged at two ends of the cylinder barrel (2), and the cylinder barrel (2) is fixedly connected with the cylinder head unit and the cylinder tail unit through bolts penetrating through the flanges; the cylinder tail unit comprises a cylinder top cover (4) and a cylinder head (41); a second guide sleeve (42) is embedded and connected at one side of the cylinder top cover (4) away from the cylinder barrel (2); the piston rod (5) penetrates through the second guide sleeve (42).

6. The double stroke limit hydraulic cylinder as claimed in claim 5 wherein: a contact cavity (52) is formed at one end of the piston rod (5) facing the tail part (11) of the cylinder, and the supporting rod (61) is in sliding fit with the contact cavity (52); a spring (53) is fixedly connected to the inner bottom surface of the contact cavity (52), and a contact plate (54) is fixedly connected to the stroke end of the spring (53); the contact plate (54) is connected to the inner wall of the contact cavity (52) in a sliding manner, and a positioning groove corresponding to the supporting rod (61) is formed in one side, facing the tail part (11) of the cylinder, of the contact plate (54).

7. The double stroke limit hydraulic cylinder as claimed in claim 6 wherein: an alignment unit is in sliding fit on the piston rod (5), and comprises a sheath (7); a plurality of grooves are formed in the inner side of the sheath (7), and swing arms (71) are hinged in the grooves; one end of the swing arm (71) is hinged in the groove, and the other end of the swing arm (71) is rotatably connected with a roller (72); the roller (72) is in rolling fit with the outer wall of the piston rod (5).

8. The double stroke limit hydraulic cylinder as recited in claim 7 wherein: the middle part of the outer wall of the sheath (7) is provided with a plurality of movable grooves which are arranged in a circumferential array mode; the movable groove is internally and rotatably connected with a ball (73), and the ball (73) is made of ceramic material.

9. The double stroke limit hydraulic cylinder as claimed in claim 8 wherein: a plurality of O-shaped sealing rings are sleeved on the outer wall of the piston (51); o-shaped sealing rings are correspondingly arranged between the cylinder bottom cover (1) and the cylinder tail (11), and O-shaped sealing rings are correspondingly arranged between the cylinder top cover (4) and the cylinder head (41).

10. The double stroke limit hydraulic cylinder as claimed in claim 9 wherein: one end of the cylinder tail (11) facing the cylinder barrel (2) is fixedly connected with a mounting plate (15) through a bolt, and the mounting plate (15) is positioned at the joint of the second cavity (14) and the first cavity (21); the supporting rod (61) penetrates through the middle of the mounting plate (15); the ball nut support (62) is located on one side of the mounting plate (15) facing the cylinder barrel (2), and the blade (63) is located on one side of the mounting plate (15) facing the cylinder tail (11).