Pull rod cylinder with buffer structure

Abstract

The utility model discloses a pull rod cylinder with a buffer structure, which is characterized in that a cylinder barrel is arranged between a front end cover and a rear end cover, and a buffer cavity is arranged on one side, close to the front end cover, of the rear end cover; the piston rod penetrates through a center hole of the front end cover and can axially move; the piston is in threaded connection with the piston rod; the piston rod drives the piston to axially move in the cylinder barrel; the buffering sleeve can be embedded into the buffering cavity, the buffering sleeve is in threaded connection with the piston rod, the buffering sleeve is provided with a plurality of first buffering holes axially parallel to the second threaded hole and a plurality of sets of second buffering holes distributed in the radial direction of the buffering sleeve at equal intervals, and each set of second buffering holes communicate with the corresponding first buffering hole; according to the pull rod cylinder with the buffering structure, in the buffering process that the buffering sleeve is embedded into the buffering cavity, the throttling area changes along with the stroke, the buffering pressure is kept uniform, damage caused by collision of the piston to the rear end cover under high-speed operation can be avoided, and the service life of the oil cylinder is effectively prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil cylinders, and in particular relates to a tie rod cylinder with a buffer structure. Background Art

[0002] The description in this section merely provides background information related to the disclosure of the present utility model and does not constitute prior art.

[0003] Tie rod cylinder is a type of hydraulic cylinder. It is connected and fixed by 4 bolts, spring washers and nuts. Compared with other types of cylinders, it is lighter, uses less materials, has lower manufacturing costs, and since most of the parts of tie rod cylinders are modularly mass-produced, subsequent maintenance of the cylinder is more convenient and cheaper. Most of the tie rod cylinders on the market today do not have buffer devices. Under the dual effects of high-speed operation and external load, the piston will cause a large impact force on the rear end cover when it retreats, which will affect the service life of the cylinder; and a small number of tie rod cylinders with buffer devices only add buffer columns to the tail of the piston to alleviate the movement speed of the piston. This throttling method can quickly reduce the speed of the piston when it runs to the tail, but because its throttling area does not change with the change of stroke, the buffer braking force generated at the beginning of the buffer is very large, which will cause a large inertial impact on the buffer cavity, which is also not conducive to the long-term use of the cylinder.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the utility model and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the utility model. Utility Model Content

[0005] In order to overcome the defects in the prior art, the utility model provides a tie rod cylinder with a buffer structure, which can avoid damage caused by the impact of the piston on the rear end cover under high-speed operation, and can effectively increase the service life of the cylinder.

[0006] The utility model discloses a tie rod cylinder with a buffer structure, comprising:

[0007] A front end cover, a rear end cover and a cylinder barrel, wherein the cylinder barrel is arranged between the front end cover and the rear end cover, the front end cover and the rear end cover are both pressed together by fasteners, and a buffer chamber is arranged on a side of the rear end cover close to the front end cover;

[0008] A piston rod, the piston rod passes through the central hole of the front end cover and can move axially;

[0009] A piston, wherein the piston is provided with a first threaded hole capable of being threadedly connected to the piston rod, and the piston rod drives the piston to perform axial movement in the cylinder;

[0010] A buffer sleeve, wherein the buffer sleeve can be embedded in the buffer cavity, the buffer sleeve is provided with a second threaded hole which can be threadedly connected to the piston rod, and the buffer sleeve is fitted with the end surface of the piston, the buffer sleeve is provided with a plurality of first buffer holes axially parallel to the second threaded hole, the buffer sleeve is provided with a plurality of groups of second buffer holes equidistantly distributed along its radial direction, and each group of the second buffer holes is connected to a single first buffer hole.

[0011] Furthermore, in the above-mentioned tie rod cylinder with a buffer structure, the piston rod is provided with a first threaded portion and a second threaded portion having a stepped shape, the diameter of the second threaded portion is smaller than the first threaded portion, the first threaded portion is connected to the first threaded hole, and the second threaded portion is connected to the second threaded hole.

[0012] Furthermore, in the above-mentioned tie rod cylinder with a buffer structure, a first connecting end is provided on a side of the front end cover close to the cylinder barrel, and an outer diameter of the first connecting end is smaller than an outer diameter of the front end cover, and the inner diameters of the two are the same.

[0013] Furthermore, in the above-mentioned tie rod cylinder with a buffer structure, a second connecting end is provided on the side of the rear end cover close to the cylinder barrel, the outer diameter of the second connecting end is smaller than the outer diameter of the rear end cover, and the inner diameters of the two are the same, and the two ends of the cylinder barrel are connected to the end faces of the first connecting end and the second connecting end.

[0014] Furthermore, in the above-mentioned tie rod cylinder with a buffer structure, the outer diameter of the piston is equal to the inner diameter of the cylinder.

[0015] Furthermore, in the above-mentioned tie rod cylinder with a buffer structure, the diameter and depth of the buffer sleeve are smaller than the diameter and depth of the buffer cavity, and when the buffer sleeve is embedded in the buffer cavity, there is a gap between the buffer sleeve and the buffer cavity.

[0016] Furthermore, in the above-mentioned tie rod cylinder with a buffer structure, the fastener includes a bolt, a spring washer and a nut, and the bolt passes through the front cover or the rear cover and is tightened by the spring washer and the nut.

[0017] It can be seen from the above technical solution that the utility model has the following beneficial effects:

[0018] The tie rod cylinder with a buffer structure described in the utility model has a continuous reduction in the number of second buffer holes and a continuous reduction in the flow area as the buffer sleeve goes deeper. The buffer pressure and decreasing speed generated in this way are also better. During the entire buffering process in which the buffer sleeve is embedded in the buffer cavity, the throttling area changes with the stroke, so that the buffer pressure remains uniform, thereby avoiding damage caused by the piston hitting the rear end cover under high-speed operation, and can effectively improve the service life of the cylinder.

[0019] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a structural cross-sectional view of a tie rod cylinder with a buffer structure in an embodiment of the utility model;

[0022] Figure 2 It is a schematic diagram of a buffer sleeve in an embodiment of the utility model;

[0023] Figure 3 It is a partial schematic diagram of the flow of hydraulic oil in the buffer sleeve and the buffer cavity in the embodiment of the utility model;

[0024] Figure 4 It is a structural schematic diagram of the piston rod in the embodiment of the utility model;

[0025] Figure 5 It is a structural schematic diagram of the front end cover in an embodiment of the utility model;

[0026] Figure 6 It is a schematic diagram of the structure of the rear end cover in an embodiment of the utility model;

[0027] Figure 7 It is a schematic diagram of a piston in an embodiment of the utility model.

[0028] The figure marks of the above drawings are: 1. piston rod; 11. first threaded portion; 12. second threaded portion; 2. piston; 21. first threaded hole; 3. buffer sleeve; 31. second threaded hole; 32. first buffer hole; 33. second buffer hole; 4. front end cover; 41. first connecting end; 5. rear end cover; 51. buffer chamber; 52. second connecting end; 6. cylinder barrel; 7. bolt; 8. spring washer; 9. nut. DETAILED DESCRIPTION

[0029] 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.

[0030] It should be noted that in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0031] The utility model is described in detail below with reference to the accompanying drawings and embodiments.

[0032] Reference Figures 1 to 7 , this embodiment provides a tie rod cylinder with a buffer structure, comprising:

[0033] A front end cover 4, a rear end cover 5 and a cylinder 6, wherein the cylinder 6 is arranged between the front end cover 4 and the rear end cover 5, the front end cover 4 and the rear end cover 5 are both pressed together by fasteners, and a buffer chamber 51 is provided on a side of the rear end cover 5 close to the front end cover 4;

[0034] A piston rod 1, the piston rod 1 passes through the central hole of the front end cover 4 and can move axially;

[0035] A piston 2, wherein the piston 2 is provided with a first threaded hole 21 capable of being threadedly connected to the piston rod 1, and the piston rod 1 drives the piston 2 to perform axial movement in the cylinder 6;

[0036] like Figure 2As shown, the buffer sleeve 3 can be embedded in the buffer cavity 51, the buffer sleeve 3 is provided with a second threaded hole 31 which can be threadedly connected to the piston rod 1, and the buffer sleeve 3 is fitted with the end surface of the piston 2, the buffer sleeve 3 is provided with a plurality of first buffer holes 32 axially parallel to the second threaded hole 31, the buffer sleeve 3 is provided with a plurality of groups of second buffer holes 33 equidistantly distributed along its radial direction, and each group of the second buffer holes 33 is connected to a single first buffer hole 32; further, in this embodiment, 4 first buffer holes 32 arranged in a ring matrix are selected, the first buffer holes 32 are through holes, and 4 groups of second buffer holes 33 equidistantly distributed along its radial direction are provided, and each group of second buffer holes 33 can be provided with a plurality of holes, and a single group of second buffer holes 33 is connected to a single first buffer hole 32, so as to facilitate the circulation of hydraulic oil.

[0037] Specifically, refer to Figure 4 In this embodiment, the piston rod 1 is provided with a first threaded portion 11 and a second threaded portion 12 having a stepped shape, the diameter of the second threaded portion 12 is smaller than the first threaded portion 11, the first threaded portion 11 is connected to the first threaded hole 21, the first threaded hole 21 of the piston 2 is connected and fixed to the first threaded portion 11 at the shaft shoulder, and the second threaded portion 12 is connected to the second threaded hole 31.

[0038] Specifically, refer to Figure 5 In this embodiment, a first connecting end 41 is provided on a side of the front end cover 4 close to the cylinder 6. The outer diameter of the first connecting end 41 is smaller than the outer diameter of the front end cover 4, and the inner diameters of the two are the same.

[0039] Specifically, refer to Figure 6 In this embodiment, the rear end cover 5 is provided with a second connection end 52 on one side close to the cylinder 6. The outer diameter of the second connection end 52 is smaller than the outer diameter of the rear end cover 5, and the inner diameters of the two are the same. The inner hole of the second connection end 52 and the inner hole of the rear end cover 5 jointly form the buffer cavity 51. The two ends of the cylinder 6 are connected to the end surfaces of the first connection end 41 and the second connection end 52. The outer surfaces of the cylinder 6, the first connection section 41 and the second connection end 52 are gap-matched and fit with the end surfaces.

[0040] Specifically, refer to Figure 7 In this embodiment, the outer diameter of the piston 2 is equal to the inner diameter of the cylinder 6. Under the action of the hydraulic oil, the piston 2 can move axially in the cylinder between the first connecting section 41 and the second connecting end 52.

[0041] Specifically, in this embodiment, the diameter and depth of the buffer sleeve 3 are smaller than the diameter and depth of the buffer cavity 51. When the buffer sleeve 3 is embedded in the buffer cavity 51, there is a gap between the buffer sleeve 3 and the buffer cavity 51, so the buffer sleeve 3 does not directly contact the rear end cover 5.

[0042] Specifically, in this embodiment, the fastener includes a bolt 7, a spring washer 8 and a nut 9, and the bolt 7 passes through the front end cover 4 or the rear end cover 5 and is tightened by the spring washer 8 and the nut 9; further, in this embodiment, 4 bolts are used to pass through the front end cover and the rear end cover and are tightened by the spring washer 8 and the nut 9.

[0043] With the above structure, under the action of the hydraulic oil, the piston 2 can move axially in the cylinder 6 between the first connecting section 41 and the second connecting end 52. When the buffer sleeve 3 enters the buffer cavity 51, the hydraulic oil between the piston 2 and the second connecting end 52 will be closed to form a closed space, and then the hydraulic oil will be discharged into the buffer cavity 51 through the second buffer hole 33 and the first buffer hole 31 of the buffer sleeve 3, plus the gap between the buffer sleeve 3 and the rear end cover 5. Figure 3 As shown in the figure, the hydraulic oil first flows into the first buffer hole 32 through multiple second buffer holes 33, and then flows into the cavity from the first buffer hole 32, which is the flow direction of the hydraulic oil in the closed space. In this way, the enclosed hydraulic oil will generate appropriate buffer pressure to act on the piston, so as to achieve the purpose of deceleration. Compared with the existing buffer plunger, the utility model has a larger flow area, and as the buffer sleeve goes deeper, the number of second buffer holes continues to decrease, and the flow area also continues to decrease, so that the buffer pressure and the decreasing speed generated are also better. In the tie rod cylinder with a buffer structure of this embodiment, during the entire buffering process when the buffer sleeve is embedded in the buffer cavity, the throttling area changes with the stroke, so that the buffer pressure remains uniform, thereby avoiding damage caused by the piston hitting the rear end cover under high-speed operation, and can effectively improve the service life of the cylinder.

[0044] The utility model uses specific embodiments to illustrate the principle and implementation method of the utility model. The description of the above embodiments is only used to help understand the technical solution and core idea of ​​the utility model. At the same time, for ordinary technicians in this field, according to the idea of ​​the utility model, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the utility model.

Claims

1. A tie rod cylinder with a buffer structure, characterized in that: include: A front end cover, a rear end cover and a cylinder barrel, wherein the cylinder barrel is arranged between the front end cover and the rear end cover, the front end cover and the rear end cover are both pressed together by fasteners, and a buffer chamber is arranged on a side of the rear end cover close to the front end cover; A piston rod, the piston rod passes through the central hole of the front end cover and can move axially; A piston, wherein the piston is provided with a first threaded hole capable of being threadedly connected to the piston rod, and the piston rod drives the piston to perform axial movement in the cylinder; A buffer sleeve, wherein the buffer sleeve can be embedded in the buffer cavity, the buffer sleeve is provided with a second threaded hole which can be threadedly connected to the piston rod, and the buffer sleeve is fitted with the end surface of the piston, the buffer sleeve is provided with a plurality of first buffer holes axially parallel to the second threaded hole, the buffer sleeve is provided with a plurality of groups of second buffer holes equidistantly distributed along its radial direction, and each group of the second buffer holes is connected to a single first buffer hole.

2. The tie rod cylinder with a buffer structure according to claim 1, characterized in that: The piston rod is provided with a first threaded portion and a second threaded portion having a step shape, the second threaded portion has a smaller diameter than the first threaded portion, the first threaded portion is connected to a first threaded hole, and the second threaded portion is connected to the second threaded hole.

3. The tie rod cylinder with a buffer structure according to claim 1, characterized in that: A first connecting end is provided on a side of the front end cover close to the cylinder barrel, the outer diameter of the first connecting end is smaller than the outer diameter of the front end cover, and the inner diameters of the two are the same.

4. The tie rod cylinder with a buffer structure according to claim 3, characterized in that: A second connecting end is provided on one side of the rear end cover close to the cylinder barrel, the outer diameter of the second connecting end is smaller than the outer diameter of the rear end cover, and the inner diameters of the two are the same, and the two ends of the cylinder barrel are connected to the end faces of the first connecting end and the second connecting end.

5. The tie rod cylinder with a buffer structure according to claim 1, characterized in that: The outer diameter of the piston is equal to the inner diameter of the cylinder.

6. The tie rod cylinder with a buffer structure according to claim 1, characterized in that: The diameter and depth of the buffer sleeve are both smaller than the diameter and depth of the buffer cavity. When the buffer sleeve is embedded in the buffer cavity, there is a gap between the buffer sleeve and the buffer cavity.

7. The tie rod cylinder with a buffer structure according to claim 1, characterized in that: The fastener comprises a bolt, a spring washer and a nut. The bolt passes through the front end cover or the rear end cover and is tightened by the spring washer and the nut.

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