Hydraulic cylinder with a linear variation in tensile and compression damping

A hydraulic cylinder with a linear variation in tensile and compression damping, which comprises a reservoir drum, a working cylinder fixedly arranged inside the reservoir drum, a piston assembly slidably connected with the reservoir drum, and a damping-adjusting valve assembly. An energy storage is arranged in the reservoir drum, and an energy-storage chamber is formed between the energy storage and the working cylinder, a working cylinder flow passage and an energy-storage flow passage are formed on an inwall of the reservoir drum, and both are connected with the damping-adjusting valve assembly. By adjusting oil flow damping in the hydraulic cylinder using the damping-adjusting valve assembly, the hydraulic cylinder can provide damping characteristics matching with force situations according to the force situations, and ensure the elastic touch and hovering at any position during use.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Chinese patent CN202222524415.1, named “hydraulic cylinder with a linear variation in tensile and compression damping”, and filed on Sep. 23, 2022, and granted on Jan. 31, 2023, all of which is herein incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to hydraulic cylinder technical field, in particular to a hydraulic cylinder with a linear variation in tensile and compression damping.

BACKGROUND

Commonly used robots or human knee joints currently mainly make the air spring support pole or the traditional constant-value damper, causing the leg posture to harden when used, damping under different bending and stretching states can not achieve an effective match, resulting in rigid posture and easy to fall in the process of walking.

The Chinese patent application CN202020576983.4 discloses a knee prosthesis and a hydraulic damper for prosthesis. The hydraulic damper for prosthesis comprises a hydraulic cylinder and an energy storage arranged on the hydraulic cylinder. A first end of the energy storage is connected with a rod chamber through a first pipeline, and the first end of the energy storage is connected with a non rod chamber through a second pipeline. The second pipeline comprises a first branch pipe and a second branch pipe arranged in parallel. A first one-way valve is arranged on the first branch pipe and a second one-way valve is arranged on the second branch pipe. Control directions of the first one-way valve and the second one-way valve are in opposite. A first control valve is arranged on the first branch pipe and a second control valve is arranged on the second branch pipe. Working process of the hydraulic damper mentioned above still does not have the linear variable function in damping, and it is not beneficial to apply the damper to different working conditions.

SUMMARY

In view of the deficiencies above, the purpose of the present disclosure is to provide a hydraulic cylinder with a linear variation in tensile and compression damping. The damping of the present hydraulic cylinder can be adjusted according to the requirements, so as to meet the requirements of different working conditions.

To solve the above technical problems, the disclosed technical scheme of the present disclosure is as follows:

A hydraulic cylinder with a linear variation in tensile and compression damping, comprises a reservoir drum, a working cylinder, a piston assembly and a damping-adjusting valve assembly; the working cylinder is fixedly arranged inside the reservoir drum, the piston assembly is slidably connected with the working cylinder. An energy storage is arranged in the reservoir drum, and an energy-storage chamber is formed between with the energy storage and the working cylinder. A working cylinder flow passage and an energy-storage flow passage are formed on an inwall of the reservoir drum, and are both connected with the damping-adjusting valve assembly.

Optionally, the working cylinder comprises a working cylinder body, an oriented end cover and a compression valve end cover. Two sides of the working cylinder body are covered by the oriented end cover and the one-way compression valve end cover respectively. The piston assembly extends into the working cylinder body through the oriented end cover. An end cover one-way valve is arranged on the oriented end cover. An one-way compression valve is arranged on the one-way compression valve end cover, and an oil return chamber is formed between the compression valve end cover and the reservoir drum.

Optionally, a working cylinder through-hole and a working cylinder waist-shaped hole are formed on a side wall of the working cylinder body, and are both connected with the working cylinder flow passage respectively.

Optionally, a mounting passage is formed in the reservoir drum, an inner wall of the mounting passage is formed with a first connection ring groove of working cylinder, a second connection ring groove of working cylinder, an energy-storage connection ring groove and a one-way valve connection ring groove. The first connection ring groove of working cylinder is connected with the working cylinder through-hole, and the second connection ring groove of working cylinder is connected with the working cylinder waist-shaped hole, and the energy-storage connection ring groove is connected with the energy-storage chamber, and the one-way valve connection ring groove is connected with the oil return chamber.

Optionally, the working cylinder flow passage includes a first working flow passage connected with the first connection ring groove of working cylinder, and a second working flow passage connected with the energy-storage connection ring groove. The energy-storage flow passage includes a first energy-storage path connected with the energy-storage connection ring groove, and a second energy-storage path connected with both the energy-storage connection ring groove and the one-way valve connection ring groove.

Optionally, the damping-adjusting valve assembly comprises a valve seat, a shift lever, an adjusting outer sleeve and an adjusting inner sleeve. The adjusting outer sleeve is installed inside the valve seat, and the adjusting inner sleeve is rotationally installed inside the adjusting outer sleeve, the shift lever is connected with the adjusting inner sleeve to drive the adjusting inner sleeve to turn round.

Optionally, an arc-shaped groove is formed on the adjusting outer sleeve, and an adjusting through-slot is formed on the adjusting inner sleeve. Turn round the adjusting inner sleeve to change the opposite area of the adjusting through-slot and the arc-shaped groove.

Optionally, the energy storage comprises an energy-storage spring, a spring end cover and a seal end cover. The seal end cover is installed on the spring end cover. Two ends of the energy-storage spring are connected with the spring end cover and the reservoir drum respectively. The energy-storage chamber is formed between the seal end cover and the working cylinder.

Optionally, the piston assembly comprises a piston plate, and a piston rod fixedly arranged on the piston plate. The piston plate is slidably installed inside the working cylinder.

Optionally, a base is installed inside the reservoir drum, a mounting ring is formed on the base. The mounting ring is arranged on and abuts against the working cylinder, an oil return chamber is formed between the mounting ring and the working cylinder. A mounting ring through-hole is formed on the mounting ring.

Beneficial effects of the disclosure: by adjusting oil flow damping in the hydraulic cylinder using the damping-adjusting valve assembly, the hydraulic cylinder can provide damping characteristics matching with force situations according to the force situations, and ensure the elastic touch and hovering at any positions during use.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Providing a clear and complete description for the technical solutions in the embodiments of the present disclosure in combination with the accompanying drawings.

A hydraulic cylinder with a linear variation in tensile and compression damping, comprises an reservoir drum1, a working cylinder2, a piston assembly3, and a damping-adjusting valve assembly4. The working cylinder2is fixedly arranged inside the reservoir drum1, the piston assembly3is slidably connected with the reservoir drum1. An energy storage5is arranged in the reservoir drum1, and an energy-storage chamber6is formed between with the energy storage5and the working cylinder2. A working cylinder flow passage7and an energy-storage flow passage8are formed on inwall of the reservoir drum1, and both are connected with the damping-adjusting valve assembly4. During the compression process of the hydraulic cylinder, in the working cylinder2, the oil below the piston assembly3flows into the damping-adjusting valve assembly4through the working cylinder flow passage7, and then returns back above the piston assembly3of the working cylinder through the damping-adjusting valve assembly4. During the tensile process of the hydraulic cylinder, in the working cylinder2, the oil above the piston assembly3flows out of the working cylinder2, and then flows into the damping-adjusting valve assembly4through the energy-storage flow passage8, after adjusting the flow speed of the oil by the damping-adjusting valve assembly4, the oil flows into the energy-storage chamber6, and then the oil in the energy-storage chamber6flows through the energy-storage flow passage8to a tail end of the working cylinder2. After that, the oil flows into below the piston assembly3in the working cylinder2through an one-way compression valve at the tale end of the working cylinder2. By artificially adjusting the damping-adjusting valve assembly4, the oil flow damping in the hydraulic cylinder is adjusted, so that the hydraulic cylinder can provide damping characteristics matching with force situations according to the force situations, so as to ensure elastic touch and hovering at any position during use.

The working cylinder2comprises a working cylinder body2-1, an oriented end cover2-2and a compression valve end cover2-3. Two sides of the working cylinder body2-1are covered by the oriented end cover2-2and the one-way compression valve end cover2-3respectively. The piston assembly3extends into the working cylinder body2-1through the oriented end cover2-2. An end cover one-way valve2-7is arranged on the oriented end cover2-2. During the lowering process of the piston assembly3, the oil flows into the energy-storage chamber6by adjusting the damping-regulating valve assembly4, then the oil in the energy-storage chamber6flows into above the piston assembly3in the working cylinder2through the end cover one-way valve2-7. An one-way compression valve2-4is arranged on the one-way compression valve end cover2-3, so as to control the oil flow return into the working cylinder body2-1from an oil return chamber9. The oil return chamber9is formed between the compression valve end cover2-3and the reservoir drum1. The oil in the energy-storage chamber6flows into the working cylinder body2-1through the one-way compression valve2-4.

In the present embodiment, an end cover passage2-8is formed in the oriented end cover2-2. An one-way valve slice2-9and a self-lock spring2-10are arranged on the oriented end cover2-2. The end cover one-way valve2-7is assembled by the end cover passage2-8, the one-way valve slice2-9and the self-lock spring2-10. The one-way valve slice2-9is slidably installed on the oriented end cover2-2. The self-lock spring2-10is connected with the one-way valve slice2-9and the oriented end cover2-2respectively. The one-way valve slice2-9is arranged on and abuts against an opening of the end cover passage2-8. When the oil pressure in the energy-storage chamber increases, the oil pressure overcomes an elasticity of the self-lock spring2-10, so that the oil flows from the energy-storage chamber6to above the piston assembly in the working cylinder2.

A working cylinder through-hole2-5and a working cylinder waist-shaped hole2-6are formed on a side wall of the working cylinder body2-1, and are both connected with the working cylinder flow passage7respectively. The working cylinder through-hole2-5is formed at a bottom of the working cylinder body2-1. The oil below the piston assembly3flows out of the working cylinder body2-1through the working cylinder through-hole2-5. The working cylinder waist-shaped hole2-6is formed on a top of the working cylinder body2-1, so that the oil above the piston assembly3flows out of the working cylinder body2-1.

A mounting passage1-1is formed in the reservoir drum1. An inner wall of the mounting passage1-1is formed with a first connection ring groove of working cylinder1-2, a second connection ring groove of working cylinder1-3, an energy-storage connection ring groove1-4and an one-way valve connection ring groove1-5. The first connection ring groove of working cylinder1-2is connected with the working cylinder through-hole2-5, and the second connection ring groove of working cylinder1-3is connected with the working cylinder waist-shaped hole2-6, it is convenient that the oil in the working cylinder2flows into the working cylinder flow passage7between the reservoir drum1and the working cylinder2, thus facilitating the oil flows through the working cylinder flow passage7into the damping-adjusting valve assembly4. The energy-storage connection ring groove1-4is connected with the energy-storage chamber6, and the one-way valve connection ring groove1-5is connected with the oil return chamber9, so that the oil in the energy-storage chamber6can flow into the oil return chamber9through the energy-storage flow passage8, so that the reflux oil can flow into the working cylinder2.

The working cylinder flow passage7includes a first working flow passage7-1connected with the first connection ring groove of working cylinder1-2, and a second working flow passage7-2connected with the energy-storage connection ring groove1-4. The energy-storage flow passage8includes a first energy-storage path8-1connected with the energy-storage connection ring groove1-4, and a second energy-storage path8-2connected with both the energy-storage connection ring groove1-4and the one-way valve connection ring groove1-5.

The damping-adjusting valve assembly4comprises a valve seat4-1, a shift lever4-2, an adjusting outer sleeve4-3and an adjusting inner sleeve4-4. The adjusting outer sleeve4-3is arranged inside the valve seat4-1, and the adjusting inner sleeve4-4is turnably arranged inside the adjusting outer sleeve4-3. The shift lever4-2is connected with the adjusting inner sleeve4-4, so as to drive the adjusting inner sleeve4-4to turn round. The valve seat4-1is connected with the working cylinder flow passage7to facilitate the oil to flow into the valve seat4-1through the working cylinder flow passage7, and then adjust the oil damping by adjusting the adjusting outer sleeve4-3and the adjusting inner sleeve4-4.

An arc-shaped groove4-5is formed on the adjusting outer sleeve4-3, and an adjusting through-slot4-6is formed on the adjusting inner sleeve4-4. Turning round the adjusting inner sleeve4-4to change the opposite area of the adjusting through-slot4-6and the arc-shaped groove4-5, thus to change the flow path area of the oil, thus changing the oil damping.

The energy storage5comprises an energy-storage spring5-1, a spring end cover5-2and a seal end cover5-3. The seal end cover5-3is installed on the spring end cover5-2. Two ends of the energy-storage spring5-1are connected with the spring end cover5-2and the reservoir drum1respectively. The energy-storage chamber6is formed between the seal end cover5-3and the working cylinder2.

The piston assembly3comprises a piston plate3-2and a piston rod3-1. The piston rod3-1is fixedly arranged on the piston plate3-2. The piston plate3-2is slidably installed inside the working cylinder2.

A base10is installed inside the reservoir drum1, a mounting ring11is formed on the base10. The mounting ring11is connected with and abuts against the working cylinder2to facilitate forming the oil return chamber9between the mounting ring11and the working cylinder2. A mounting ring through-hole11-1is formed on the mounting ring11. The oil in the energy-storage chamber6flows into the oil return chamber9through the mounting ring through-hole11-1, and then the oil flows into the working cylinder2through the one-way compression valve2-4on the compression valve end cover2-3.

The operating principle of the hydraulic cylinder of the present disclosure is as follows: When the piston assembly3is being compressed, the lower oil in the piston assembly in the working cylinder2flows into the first connection ring groove of working cylinder1-2through the working cylinder through-hole2-5. The oil in the first connection ring groove of working cylinder1-2flows into the damping-adjusting valve assembly4through the first working flow passage7-1. After damped by the damping-adjusting valve assembly4, the oil flows through the second working flow passage7-2and the energy-storage connection ring groove1-4into the energy-storage chamber6. When the oil pressure in the energy-storage chamber6increases, the oil pressure overcomes the elasticity of the self-lock spring2-10, making the oil flow out of the energy-storage chamber6, and then flow above the piston assembly in the working cylinder2.

When the piston assembly3is being stretched, the oil in the working cylinder2flows into the second connection ring groove of working cylinder1-3through the working cylinder waist-shaped hole2-6. The oil flows into the damping-adjusting valve assembly4through the first energy-storage path8-1. One part of the oil in the damping-adjusting valve assembly4flows through the second energy-storage path8-2into the energy-storage chamber6, so as to change the pressure potential energy in the energy-storage chamber6. Another part of the oil in the damping-adjusting valve assembly4flows through the second energy-storage path8-2into the oil return chamber9, and then flows below the working cylinder2through the one-way compression valve2-4.

The above description of the disclosed embodiments enables those skilled in the art to realize or use the present disclosure. Multiple modifications of these embodiments are obvious to the skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not limited to these embodiments shown herein, but conforms to the widest range consistent with the principles and novel features disclosed herein.

Despite the use of terms, the use of other terms are used merely to describe and explain the nature of the present disclosure. The interpretation of any additional limitations is contrary to the spirit of the present disclosure.