An overstroke self-deflating tension balanced cylinder

Abstract

The utility model discloses a kind of overstroke tension balance cylinder that can automatically deflate, including cylinder body, piston rod, base and pull ring, one end of cylinder body is opened and its inside is equipped with air chamber, piston rod is movably inserted in air chamber and extends middle sleeve, pull ring is fixedly connected with the front end of piston rod that extends cylinder body, the last end of piston rod is axially equipped with first sealing element, second sealing element is equipped between middle sleeve inner wall and piston rod outer wall, and between middle sleeve outer wall and cylinder body inner wall, the inner wall of cylinder body is respectively outwardly convex with safety exhaust groove at specified position, when piston rod moves to exceed safety exhaust groove, annular pressure relief passage is formed between piston rod outer wall and safety exhaust groove, gas is guided back to low-pressure area at the tail of cylinder body through annular pressure relief passage to realize automatic deflation. The utility model avoids the safety hazard that cylinder body overload, component damage etc. are caused by overstroke of tension balance cylinder, also shorten the installation distance of equipment fixing hole, increase use stroke, equipment is more compact.

Description

Technical Field

[0001] This utility model relates to the field of tension balance cylinder technology, and more specifically, to a tension balance cylinder with automatic air release capability after over-stroke. Background Technology

[0002] A tension balancing cylinder is a device that uses a power source such as air pressure, hydraulic pressure, or mechanical springs to generate a tension force opposite to the load direction, thereby counteracting or balancing the tension of an external load. Through preset force adjustment, the tension in the system is kept stable or in a dynamic equilibrium state, thus reducing the impact of external loads on equipment, structures, or operations. Traditional tension balancing cylinders or mechanical springs typically lack automatic air release functionality. When the equipment experiences overtravel, the internal pressure of the cylinder cannot be released in time, potentially leading to cylinder overload, component damage or detachment, and other safety hazards. Furthermore, traditional tension balancing cylinders use a larger hole center distance to distribute force, resulting in a longer installation distance between the mounting holes and an increased overall cylinder length, leading to larger robot joints or overall equipment dimensions and a larger space requirement. Utility Model Content

[0003] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a tension balance cylinder with automatic over-stroke depressurization. It achieves automatic over-stroke depressurization through the structure of the safety venting groove. It has a compact structure, high safety, and stable and reliable operation.

[0004] To achieve the above objectives, this utility model provides an over-stroke, automatically venting tension balance cylinder, comprising a cylinder body, a piston rod, a base, and a pull ring. One end of the cylinder body is open and has an air chamber inside. An axially arranged middle sleeve is fixedly provided on the inner wall of the cylinder body at the opening position. The piston rod is movably inserted into the air chamber and extends out of the middle sleeve. The base is fixedly sleeved on the outer wall of the rear end of the cylinder body. The pull ring is fixedly connected to the front end of the piston rod extending out of the cylinder body. A first sealing element is axially sleeved at the end of the piston rod between the outer wall of the sealing piston rod and the inner wall of the cylinder body. A second sealing element is provided between the inner wall of the middle sleeve and the outer wall of the piston rod, and between the outer wall of the middle sleeve and the inner wall of the cylinder body. Safety vent grooves are respectively provided outwardly at designated positions on both sides of the inner wall of the cylinder body. When the piston rod moves beyond the position of the safety vent groove, an annular pressure relief channel is formed between the outer wall of the piston rod and the safety vent groove. Gas is guided back to the low-pressure area at the rear end of the cylinder body through the annular pressure relief channel to achieve automatic venting.

[0005] Preferably, the first sealing element includes a piston, a first sealing ring, and a first combined seal. The piston is axially sleeved on the end of the piston rod and its limiting end abuts against it. The first sealing ring is provided in several units and is respectively sleeved on the piston rod and located between the outer wall of the piston rod and the inner wall of the piston. The first combined seal is provided in several sets and is respectively sleeved on the piston and located between the outer wall of the piston and the inner wall of the cylinder.

[0006] Preferably, the second seal includes a piston rod seal, a second sealing ring, and a second combined seal. The piston rod seal and the second combined seal are respectively spaced on the piston rod and located between the outer wall of the piston rod and the inner wall of the middle sleeve. A plurality of second sealing rings are provided and are respectively spaced on the middle sleeve and located between the outer wall of the middle sleeve and the inner wall of the cylinder.

[0007] Preferably, the system also includes a first wear-resistant sleeve and a second wear-resistant sleeve. The first wear-resistant sleeve is provided in a plurality of parts and is respectively sleeved on the outer wall of the limiting end of the piston rod and on both sides of the outer wall of the piston. The second wear-resistant sleeve is provided in a plurality of parts and is respectively sleeved on both sides of the outer wall of the front and rear ends of the piston rod and is located between the outer wall of the piston rod and the middle sleeve or the inner wall of the piston.

[0008] Preferably, a retaining ring is also included, and the inner wall of the cylinder and the outer wall of the middle sleeve are respectively provided with inwardly recessed grooves, and the cylinder and the retaining groove are fixedly installed by the retaining ring embedded in the groove.

[0009] Preferably, the outer wall of the cylinder is provided with an air inlet connector for connecting the air chamber, and the air inlet connector is provided with a valve core inside.

[0010] Preferably, a bearing seat is axially fixed at the ring hole position of the pull ring, and a needle roller bearing is embedded in the bearing seat.

[0011] Preferably, the pull ring and the piston rod extending out of the cylinder are fixedly connected by a locking nut.

[0012] Preferably, a third sealing ring is provided between the base and the outer wall of the cylinder, a muffler is installed inside the end of the base, and mounting holes are respectively opened on both sides of the front end of the base.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] This utility model features a novel structure and a reasonable design. By protruding safety vent grooves on both sides of the inner wall of the cylinder, an annular pressure relief channel can be formed with the outer wall of the piston rod when the piston rod moves beyond its travel. This allows the gas to be guided back to the low-pressure area at the rear of the cylinder for automatic venting, avoiding safety hazards such as cylinder overload and component damage caused by overtravel of the tension balance cylinder. At the same time, the hole center distance of this tension balance cylinder is relatively short, which shortens the installation distance of the equipment fixing hole, increases the working stroke, and makes the equipment more compact, especially suitable for robot swing arms. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a cross-sectional structural diagram of the over-stroke automatic deflation tension balance cylinder provided in this embodiment of the utility model;

[0017] Figure 2 This is a longitudinal cross-sectional structural schematic diagram of the over-stroke automatic venting tension balance cylinder provided in this embodiment of the utility model;

[0018] Figure 3 This is an enlarged longitudinal section view of the safety exhaust groove position of the over-stroke automatic venting tension balance cylinder provided in this embodiment of the utility model;

[0019] Figure 4 This is an enlarged longitudinal section view of the first seal of the over-stroke, automatically venting tension balance cylinder provided in this embodiment of the utility model.

[0020] Figure 5 This is an enlarged longitudinal section view of the second seal of the over-stroke, automatically venting tension balance cylinder provided in this embodiment of the utility model.

[0021] Figure 6 This is a schematic diagram of the normal state of the over-stroke automatic venting tension balance cylinder provided in this embodiment of the utility model;

[0022] Figure 7 This is a schematic diagram of the tension state of the over-stroke, automatically venting tension balance cylinder provided in this embodiment of the utility model. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] Please refer to Figure 1 The present invention provides an over-stroke, automatically deflated tension balance cylinder, including a cylinder body 1, a piston rod 2, a base 3, a pull ring 4, a first seal 5, and a second seal 6, etc. The components of this embodiment will be described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 and Figure 2 As shown, one end of the cylinder body 1 is open and an air chamber 10 can be provided inside it. An axially arranged middle sleeve 11 is fixedly provided on the inner wall of the cylinder body 1 at the opening position. The piston rod 2 is movably inserted into the air chamber 10 of the cylinder body 1 and extends out of the middle sleeve 11. The base 3 is fixedly sleeved on the outer wall of the tail of the cylinder body 1. The pull ring 4 is fixedly connected to the front end of the piston rod 2 that extends out of the cylinder body 1. The end of the piston rod 2 is axially sleeved with a first sealing element 5 located between the outer wall of the sealing piston rod 2 and the inner wall of the cylinder body 1. A second sealing element 6 is provided between the inner wall of the middle sleeve 11 and the outer wall of the piston rod 2, and between the outer wall of the middle sleeve 11 and the inner wall of the cylinder body 1. Safety exhaust grooves 13 are respectively provided outwardly at designated positions on both sides of the inner wall of the cylinder body 1.

[0026] like Figure 3 As shown, in specific implementation, the position of the safety vent groove 13 is preferably set between one-half and two-thirds of the length of the cylinder 1 from back to front. When the piston rod 2 moves beyond the position of the safety vent groove 13, an annular pressure relief channel is formed between the outer wall of the piston rod 2 and the safety vent groove 13. The gas is guided back to the low-pressure area at the tail of the cylinder 1 through the annular pressure relief channel to achieve automatic gas release. The safety vent groove 13 of this embodiment can automatically release high-pressure gas, avoid cylinder overload or component damage, significantly improve safety, and does not require additional control devices. The structure is simple and reliable.

[0027] The cylinder body 1 serves as the main structure, with an internal air chamber 10 that accommodates the movement of the piston rod 2 and provides a pressure-sealed space. The gas medium in the air chamber 10 is preferably nitrogen, which is non-toxic, odorless, and has no flash point, meeting environmental and safety requirements. The cylinder body 1 has a compact structure, shortens the center distance of the holes, and reduces the overall size of the equipment, making it suitable for space-constrained applications. The piston rod 2 transmits the pulling force and reciprocates within the air chamber. The middle sleeve 11 is fixed to the open end of the cylinder body 1, supporting and guiding the piston rod 2 and assisting in sealing, ensuring the stability and coaxiality of the piston rod 2's movement. The pull ring 4 is fixedly connected to the front end of the piston rod 3 and is used to connect to an external load, transmitting the force of the piston rod 3 to the load.

[0028] like Figure 4 As shown, specifically, the first sealing element 5 may include a piston 51, a first sealing ring 52, and a first combined seal 53. The piston 51 is axially sleeved on the end of the piston rod 2 and its limiting end abuts against it. The first sealing ring 52 is provided in several units and is respectively sleeved on the piston rod 2 and located between the outer wall of the piston rod 2 and the inner wall of the piston 51. The first combined seal 53 is provided in several sets and is respectively sleeved on the piston 51 and located between the outer wall of the piston 51 and the inner wall of the cylinder 1.

[0029] like Figure 5 As shown, the second seal 6 may further include a piston rod seal 61, a second sealing ring 62, and a second combined seal 63. The piston rod seal 61 and the second combined seal 63 are respectively spaced on the piston rod 2 and located between the outer wall of the piston rod 2 and the inner wall of the middle sleeve 11. A plurality of second sealing rings 62 are provided and are respectively spaced on the middle sleeve 11 and located between the outer wall of the middle sleeve 11 and the inner wall of the cylinder body 1.

[0030] In this embodiment, both the first combined seal 53 and the second combined seal 63 can adopt the common combination structure of "O-ring + retaining ring + dust cover" on the market. Depending on the actual needs, the first combined seal 53 can also adopt a one-way combined seal or a two-way combined seal. This design can meet the multiple sealing requirements of the tension balance cylinder under complex working conditions, and can also prevent dust from entering the air chamber 10 through the gaps and affecting the working performance of the balance cylinder. This embodiment does not limit its structure, so it will not be described in detail.

[0031] Preferably, it may also include a first wear-resistant sleeve 71 and a second wear-resistant sleeve 72. The first wear-resistant sleeve 71 is provided in several parts and is respectively sleeved on the outer wall of the limiting end of the piston rod 2 and on both sides of the outer wall of the piston 51. The second wear-resistant sleeve 72 is provided in several parts and is respectively sleeved on both sides of the outer wall of the front and rear ends of the piston rod 2 and is located between the outer wall of the piston rod 2 and the middle sleeve 11 or the inner wall of the piston 51.

[0032] Among them, the first wear-resistant sleeve 71 and the second wear-resistant sleeve 72 can further ensure the coaxiality of the cylinder 1 and the piston rod 2, making the movement smoother, extending the service life, and preventing uneven wear and air leakage.

[0033] For ease of assembly and maintenance, a retaining ring 81 may also be included. The inner wall of the cylinder body 1 and the outer wall of the middle sleeve 11 are respectively provided with inwardly recessed grooves, and the cylinder body 1 and the retaining groove are fixedly installed by the retaining ring 81 embedded in the groove.

[0034] Specifically, the outer wall of the cylinder body 1 may be provided with an air inlet 9 that connects to the air chamber 10, so as to facilitate the air inlet 10. The air inlet 9 is provided with a valve core 91 inside, which can prevent gas leakage after inflation and ensure that the air chamber 10 can stably maintain the required pressure.

[0035] To prevent the pull ring 4 from loosening during operation and to ensure effective force transmission, the pull ring 4 and the piston rod 2 extending out of the cylinder body 1 can be fixedly connected by a locking nut 43.

[0036] Preferably, a bearing housing 41 can be axially fixed at the ring hole position of the pull ring 4, and a needle roller bearing 42 is embedded in the bearing housing 41.

[0037] Among them, the needle roller bearing 42 can achieve high load capacity and high rigidity in a small space, which enables the tensile force of external load to be flexibly transmitted from multiple angles, while significantly reducing rotational friction loss. It is particularly suitable for equipment that requires frequent turning or swinging (such as robot end effectors). The needle roller bearing 42 can withstand greater radial force while effectively avoiding the wear problem of hinge structure.

[0038] In this embodiment, a third sealing ring 31 may be provided between the base 3 and the outer wall of the cylinder 1. In order to reduce the noise generated by the operation of the tension balance cylinder, a muffler 32 is installed inside the end of the base 3, and mounting holes 33 are respectively opened on both sides of the front end of the base 3.

[0039] Furthermore, in order to prevent dust and protect the internal seals, a protective cover 44 may also be included, which is fixedly fitted at the connection position between the pull ring 4 and the cylinder body 1.

[0040] The working principle of this embodiment is as follows:

[0041] like Figure 6 and Figure 7As shown, firstly, nitrogen is introduced into the air chamber 10 inside the cylinder body 1 of the tension balance cylinder through the air inlet 9. Then, the pull ring 4 is fixedly connected to the external load. The piston rod 2 moves in the air chamber 10 under the pull of the external load. The piston 51 at its end generates a pull force opposite to the direction of the external load under the action of air pressure. When the piston rod 2 moves beyond the position of the safety exhaust groove 13 due to overtravel, an annular pressure relief channel is formed between the outer wall of the piston rod 2 and the safety exhaust groove 13. The high-pressure nitrogen automatically flows back to the low-pressure area at the tail of the cylinder body 1 to achieve safe pressure relief and avoid overload damage.

[0042] The technical parameters of this tension balance cylinder are: inflation pressure 65 BAR, initial tension 2000 Kg, final tension 3800 Kg, and maximum tension stroke 227 MM.

[0043] In summary, this utility model, by protruding safety vent grooves on both sides of the inner wall of the cylinder, forms an annular pressure relief channel with the outer wall of the piston rod when the piston rod moves beyond its travel, allowing the gas to be guided back to the low-pressure area at the rear of the cylinder for automatic venting. This avoids safety hazards such as cylinder overload and component damage caused by overtravel in the tension balance cylinder. At the same time, the short center-to-center distance of the holes in this tension balance cylinder shortens the installation distance of the equipment fixing holes, increases the working stroke, and makes the equipment more compact, especially suitable for robot swing arms.

[0044] It should be noted that, based on actual needs, this utility model is particularly applicable to the application on the swing arm of a robot. By generating a pulling force opposite to the load direction, it counteracts the tensile load borne by the end effector of the robotic arm when gripping and transporting workpieces, thereby reducing the stress load on components such as motors, gears, and connectors, reducing wear and failure risks, and extending the service life of the robot. It has a wide range of applications, not limited to the robots mentioned in this embodiment.

[0045] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. An over-travel self-bleeding pull-balance cylinder, characterized by: The system includes a cylinder, a piston rod, a base, and a pull ring. One end of the cylinder is open, and an air chamber is provided inside. An axially arranged middle sleeve is fixedly installed on the inner wall of the cylinder at the opening position. The piston rod is movably inserted into the air chamber and extends out of the middle sleeve. The base is fixedly sleeved on the outer wall of the rear of the cylinder. The pull ring is fixedly connected to the front end of the piston rod extending out of the cylinder. A first sealing element is axially sleeved at the end of the piston rod between the outer wall of the sealing piston rod and the inner wall of the cylinder. A second sealing element is provided between the inner wall of the middle sleeve and the outer wall of the piston rod, and between the outer wall of the middle sleeve and the inner wall of the cylinder. Safety vent grooves are respectively provided on both sides of the inner wall of the cylinder at designated positions. When the piston rod moves beyond the position of the safety vent groove, an annular pressure relief channel is formed between the outer wall of the piston rod and the safety vent groove. Gas is guided back to the low-pressure area at the rear of the cylinder through the annular pressure relief channel to achieve automatic gas release.

2. The tension balance cylinder with automatic deflation capability after over-stroke as described in claim 1, characterized in that: The first sealing element includes a piston, a first sealing ring, and a first combined seal. The piston is axially sleeved on the end of the piston rod and its limiting end abuts against it. The first sealing ring is provided in several parts and is respectively sleeved on the piston rod and located between the outer wall of the piston rod and the inner wall of the piston. The first combined seal is provided in several sets and is respectively sleeved on the piston and located between the outer wall of the piston and the inner wall of the cylinder.

3. A tension balance cylinder with automatic deflation capability for over-stroke operation according to claim 2, characterized in that: The second sealing element includes a piston rod seal, a second sealing ring, and a second combined seal. The piston rod seal and the second combined seal are respectively spaced on the piston rod and located between the outer wall of the piston rod and the inner wall of the middle sleeve. The second sealing ring is provided in several parts and is respectively spaced on the middle sleeve and located between the outer wall of the middle sleeve and the inner wall of the cylinder.

4. A tension balance cylinder with automatic deflation capability for over-stroke operation as described in claim 3, characterized in that: It also includes a first wear-resistant sleeve and a second wear-resistant sleeve. The first wear-resistant sleeve is provided in several parts and is respectively sleeved on the outer wall of the limiting end of the piston rod and on both sides of the outer wall of the piston. The second wear-resistant sleeve is provided in several parts and is respectively sleeved on both sides of the outer wall of the front and rear ends of the piston rod and located between the outer wall of the piston rod and the middle sleeve or the inner wall of the piston.

5. A tension balance cylinder with automatic deflation capability for over-stroke operation according to claim 1, characterized in that: It also includes a retaining ring, and the inner wall of the cylinder and the outer wall of the middle sleeve are respectively provided with inwardly recessed grooves. The cylinder and the retaining groove are fixedly installed by the retaining ring embedded in the groove.

6. A tension balance cylinder with automatic deflation capability for over-stroke operation according to claim 1, characterized in that: The cylinder body has an inflation connector on its outer wall that connects to the air chamber, and the inflation connector has a valve core inside.

7. A tension balance cylinder with automatic deflation capability for over-stroke operation according to claim 1, characterized in that: A bearing seat is axially fixed at the ring hole position of the pull ring, and a needle roller bearing is embedded in the bearing seat.

8. A tension balance cylinder with automatic deflation capability for over-stroke operation according to claim 1, characterized in that: The pull ring and the piston rod extending out of the cylinder are fixedly connected by a locking nut.

9. A tension balance cylinder with automatic deflation capability for over-stroke operation according to claim 1, characterized in that: A third sealing ring is provided between the base and the outer wall of the cylinder. A muffler is installed inside the end of the base. Mounting holes are provided on both sides of the front end of the base.

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