Design method of hydraulic buffer for hinged door

Abstract

A design method for a hinged door closing hydraulic buffer includes a cylinder, a piston rod, a piston, an energy storage spring, and an oil seal. The oil seal divides the cylinder cavity into an oil-free chamber and an oil-filled chamber located below the oil-free chamber. The piston is located in the oil-filled chamber, and the energy storage spring is located in the oil-free chamber. The piston divides the oil-filled chamber into an upper oil chamber and a lower oil chamber. An oil passage connecting the upper and lower oil chambers is defined on the oil plug rod. A valve needle is installed in the cylinder to adjust the amount of oil flowing through the passage. The piston is movably mounted on the piston rod. As the piston rod moves upward, the piston separates from the piston rod to form an oil gap connecting the upper and lower oil chambers. The valve needle adjusts the amount of oil flowing through the passage as the piston rod moves downward. The stiffness of the energy storage spring is designed to adjust the cylinder rotational force required to drive the piston rod upward, and the shape and position of the valve needle are designed to adjust the speed of the piston rod's downward movement. The present invention makes door opening more labor-saving, reduces the cost of the buffer, and has a simple structure and high practicality.

Description

Technical Field

[0001] The invention relates to a design method of a hinged door hydraulic buffer, belonging to the technical field of door hydraulic buffers. Background Art

[0002] Doors in large offices (as well as commercial properties, shopping malls, and supermarkets) are often equipped with hydraulic dampers (also known as closers, hydraulic door closers, hydraulic door dampers, or concealed closers) to control the speed of door closing. A door closer is a spring-like hydraulic device attached to the door hinge, typically consisting of a spring and a hydraulic cylinder. When the door is opened, the piston rod inside the hydraulic cylinder moves downward, compressing the spring and storing energy. When the door is closed, the spring releases this potential energy, pushing the piston rod downward and closing the door. A flow regulating valve is provided in the hydraulic cylinder to control the flow and flow rate of the hydraulic oil, form a damping force, and adjust the door closing speed to prevent sudden contact between the door leaf and the door frame when closing the door, and to reduce the collision between the door leaf and the door frame; when opening the door, the door leaf is pushed by the door opening force to drive the piston rod to extend upward, so that the oil chamber pressure in the hydraulic cylinder changes to push open the valve on the piston, so that the piston rod continues to extend upward to achieve the purpose of opening the door. When opening the door, a large force needs to be applied to push the door leaf to push open the valve on the piston. The door closer is not labor-saving enough when in use, the internal space of the hydraulic cylinder is small, the structure of the flow regulating valve and the valve on the piston is complex, there are many parts, the assembly efficiency is low, and the cost of the product is relatively high. Summary of the Invention

[0003] The design method of the hinge door closing hydraulic buffer provided by the present invention is that the rotation of the oil cylinder drives the piston rod to move upward, which separates the piston and the piston rod to form an oil gap, reduces the force required to open the door, and saves more effort to open the door. The piston serves as a separating seal between the upper oil chamber and the lower oil chamber, and also as a movable part connecting the upper oil chamber and the lower oil chamber when the piston rod moves upward, thereby realizing the movement characteristics of the piston rod moving upward quickly and buffering the downward movement, and simplifying the structure inside the oil cylinder, making it easier to assemble and form, reducing the cost of the buffer, and having a simple structure and high practicality.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The design method of the hydraulic buffer for hinged door closing includes an oil cylinder, a piston rod which moves axially with the rotation of the oil cylinder, a piston which is sealed with the inner wall of the oil cylinder, an energy storage spring which is compressed with the upward movement of the piston rod, and an oil seal which is sealed with the piston rod and the inner wall of the oil cylinder. The oil seal divides the inner cavity of the oil cylinder into an oil-free cavity and an oil cavity located below the oil-free cavity. The piston is located in the oil cavity, the energy storage spring is located in the oil-free cavity, and the piston divides the oil cavity into an upper oil cavity and a lower oil cavity. The invention is characterized in that: in the An oil passage connecting the upper oil chamber and the lower oil chamber is provided on the piston rod, and a valve needle which can adjust the oil flow through the oil passage is installed in the oil cylinder. The piston is movably mounted on the piston rod. As the piston rod moves upward, the piston is separated from the piston rod to form an oil gap connecting the upper oil chamber and the lower oil chamber. The valve needle adjusts the oil flow through the oil passage as the piston rod moves downward. The stiffness of the energy storage spring is designed to adjust the cylinder rotation force required to drive the piston rod upward, and the shape and position of the valve needle are designed to adjust the speed of the downward movement of the piston rod.

[0006] Preferably, the upper end of the piston rod passes through the oil seal and extends into the oil-free chamber to cooperate with the energy storage spring, and the lower end of the piston rod extends into the oil chamber in a cross shape. The oil passage is opened at the lower end of the piston rod, and is composed of an axial oil passage arranged along the axial direction and a radial oil passage arranged along the radial direction, which are cross-connected. The valve needle is axially arranged in the oil chamber and extends into the axial oil passage. The valve needle is a multi-stage variable diameter shape with a diameter decreasing from top to bottom.

[0007] Preferably, the valve needle is composed of multiple segments, the diameters of the segments decrease from top to bottom, the difference between the diameter of the topmost segment and the inner diameter of the axial oil channel does not exceed 0.05~0.2 mm, and the difference in diameters between adjacent segments is 0.2~0.5 mm.

[0008] Preferably, the lower end of the oil cylinder is sealed by a screw plug, the screw plug thread is fitted into the lower end cover of the oil cylinder and is sealed with the lower end cover of the oil cylinder, the lower end of the valve needle is a spherical ball head end, and an arc groove is provided on the top surface of the screw plug that cooperates with the ball head end and is arranged radially, and the ball head end extends into the arc groove. The number of segments in the valve needle, the length of each segment, the diameter difference between adjacent segments, and the axial position of the screw plug at the lower end of the oil cylinder are designed to adjust the number of speed changes from slow to fast when the piston rod moves downward and the speed change of the piston rod each time the speed changes.

[0009] Preferably, the piston includes a piston body sleeved on the lower end of the piston rod and a contact sealing ring installed on the piston body. The contact sealing ring is pressed against the inner wall of the oil cylinder. The piston body is clearance-matched with the lower end of the piston rod and the inner wall of the oil cylinder respectively. The piston body is separated from the piston rod as the piston rod moves upward to form an oil gap connecting the upper oil chamber and the lower oil chamber, and is pressed against the piston rod as the piston rod moves downward.

[0010] Preferably, an annular groove is provided at the lower end of the piston rod, and an elastic retaining ring is installed in the annular groove. The elastic retaining ring is located below the piston body and is axially separated from the piston body. The piston body abuts against the elastic retaining ring as the piston rod moves upward, and is separated from the piston rod to form an oil gap. The axial spacing between the piston body and the elastic retaining ring is 0.3~1 mm.

[0011] Preferably, an inwardly recessed annular positioning groove is provided on the piston body, the contact sealing ring is clamped in the annular positioning groove, and the annular positioning groove is coated with grease.

[0012] Preferably, a radially arranged cross bar is fixed to the upper end of the piston rod, and the end of the cross bar passes through the oil cylinder. A spiral hole is provided on the oil cylinder for the end of the cross bar to pass through and move.

[0013] Preferably, the oil cylinder is equipped with a guide column that cooperates with the upper end of the piston rod and a spring matching column that cooperates with the energy storage spring. The lower end of the guide column is provided with a matching groove, the upper end of the piston rod extends into the matching groove, the upper end of the guide column is spherical in shape and contacts with the lower end of the spring matching column, the spring matching column extends into the energy storage spring, the lower end of the energy storage spring is abutted against the spring matching column, and the upper end is abutted against the upper end of the oil cylinder. The guide column is matched with the inner wall of the oil cylinder, and pushes the spring matching column to compress the energy storage spring as the piston rod moves upward. The length of the guide column is designed, the length of the energy storage spring is adjusted, and thus the stiffness of the energy storage spring is designed.

[0014] Preferably, the inner wall of the oil cylinder has an annular step surface located above the oil seal, a spring seat is provided on the top surface of the oil seal, an oil seal spring is sandwiched between the spring seat and the annular step surface, the upper end of the piston rod passes through the oil seal, the spring seat and the oil seal spring and cooperates with the guide column, and the spring seat and the oil seal spring are respectively clearance-matched with the piston rod.

[0015] The beneficial effects of the invention are:

[0016] The design method of the hinge door closing hydraulic buffer of the present invention is that the oil cylinder serves as the rotating axis of the door hinge, and the rotation of the door hinge drives the oil cylinder to rotate, thereby causing the piston rod to move axially in the oil cylinder. When the hinge is unfolded, the rotation of the oil cylinder drives the piston rod to move upward and compresses the energy storage spring to form the door opening process. After the door hinge is unfolded into place, the energy storage spring pushes the piston rod downward through elastic force, thereby driving the oil cylinder to rotate, causing the door hinge to retract, forming the door closing process; when the door is opened, external force pushes the door hinge to unfold, driving the oil cylinder to rotate, causing the piston rod to move upward, and at this time the piston will separate from the piston rod. The oil gap connecting the upper oil chamber and the lower oil chamber is formed. The volume of the upper oil chamber decreases and the pressure increases as the piston rod moves upward. The formation of the oil gap increases the flow rate, causing the oil to flow quickly from the upper oil chamber to the lower oil chamber, which quickly reduces the oil pressure in the upper oil chamber. The piston rod can move upward quickly to achieve the purpose of quickly opening the door. The rotation of the oil cylinder drives the piston rod to move upward, which will separate the piston and the piston rod to form an oil gap, reducing the force required to open the door and making it more labor-saving to open the door. The initial stiffness of the energy storage spring is designed to adjust the cylinder rotation force required to drive the piston rod upward, thereby Adjust the force required to open the door and reduce the probability of accidental door opening when the external force is small; when closing the door, the energy storage spring pushes the piston rod downward to make the piston rod and piston contact again, and the width of the oil gap is reduced to zero. The volume of the lower oil chamber decreases with the downward movement of the piston rod, and the pressure increases. The oil can only flow from the lower oil chamber to the upper oil chamber through the oil passage. At this time, the valve adjusts the oil flow through the oil passage to form a damping force on the downward movement of the piston rod, forming a buffer for the downward movement of the piston rod, forming a buffered closing of the door hinge, and realizing buffered door closing. By designing the shape of the valve needle and position to adjust the amount of oil flowing through the oil channel during the downward movement of the piston rod, and by adjusting the speed of the downward movement of the piston rod, the purpose of adjusting the door closing speed is achieved, thereby preventing sudden contact between the door leaf and the door frame and reducing the collision between the door leaf and the door frame; the piston serves as a separating seal between the upper oil chamber and the lower oil chamber, and as a movable part connecting the upper oil chamber and the lower oil chamber when the piston rod moves upward, thereby realizing the movement characteristics of the piston rod moving upward quickly and buffering the downward movement, and simplifying the structure inside the oil cylinder, making it easier to assemble and form, reducing the cost of the buffer, and having a simple structure and high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the hinge door closing hydraulic buffer in a specific implementation manner.

[0018] Figure 2 This is a partial schematic diagram of the hinged door closing hydraulic buffer.

[0019] Figure 3 This is a schematic diagram of the piston rod moving upward and separating from the piston to form an oil gap.

[0020] Figure 4 This is a schematic diagram of the piston rod moving downward and pressing against the piston. DETAILED DESCRIPTION

[0021] The following combination Figures 1 to 4 The embodiments of the present invention are described in detail.

[0022] The design method of the hydraulic buffer for hinged door closing includes a cylinder 1, wherein the cylinder 1 is provided with a piston rod 2 which moves axially with the rotation of the cylinder 1, a piston 3 which is sealed with the inner wall of the cylinder 1, an energy storage spring 4 which is compressed with the upward movement of the piston rod 2, and an oil seal 5 which is sealed with the piston rod 2 and the inner wall of the cylinder 1. The oil seal 5 divides the inner cavity of the cylinder 1 into an oil-free cavity and an oil cavity located below the oil-free cavity. The piston 3 is located in the oil cavity, the energy storage spring 4 is located in the oil-free cavity, and the piston 3 divides the oil cavity into an upper oil cavity A and a lower oil cavity B. The invention is characterized in that: in the piston rod 2 is provided with an oil passage 6 connecting the upper oil chamber A and the lower oil chamber B, a valve needle 7 for adjusting the oil flow rate of the oil passage 6 is installed in the oil cylinder 1, the piston 3 is movably mounted on the piston rod 2, and the piston 3 is separated from the piston rod 2 as the piston rod 2 moves upward to form an oil gap C connecting the upper oil chamber A and the lower oil chamber B. The valve needle 7 adjusts the oil flow rate of the oil passage 6 as the piston rod 2 moves downward. The stiffness of the energy storage spring 4 is designed to adjust the rotational force of the oil cylinder 1 required to drive the piston rod 2 upward, and the shape and position of the valve needle 7 are designed to adjust the speed of the downward movement of the piston rod 2.

[0023] The design method of the hinge door closing hydraulic buffer described above is that the oil cylinder 1 serves as the rotating shaft of the door hinge. The rotation of the door hinge drives the oil cylinder 1 to rotate, thereby causing the piston rod 2 to move axially in the oil cylinder 1. When the hinge is unfolded, the oil cylinder 1 rotates to drive the piston rod 2 to move upward and compress the energy storage spring 4 to form a door opening process. After the door hinge is unfolded, the energy storage spring 4 pushes the piston rod 2 downward through the elastic force, thereby driving the oil cylinder 1 to rotate, causing the door hinge to retract and forming a door closing process; when opening the door, the external force pushes the door hinge to unfold, driving the oil cylinder 1 to rotate, causing the piston rod 2 to move upward. At this time, the piston 3 will separate from the piston rod 2 to form an oil gap C connecting the upper oil chamber A and the lower oil chamber B. The volume of the upper oil chamber A decreases and the pressure increases as the piston rod 2 moves upward. The formation of the oil gap C increases the flow rate, causing the oil to flow quickly from the upper oil chamber A to the lower oil chamber B. The oil pressure in the upper oil chamber A is quickly reduced, and the piston rod 2 can move upward quickly to achieve the purpose of quickly opening the door. The rotation of the cylinder 1 drives the piston rod 2 to move upward, which will separate the piston 3 from the piston rod 2 to form an oil gap C, reducing the force required to open the door and making door opening more labor-saving. The initial stiffness of the energy storage spring is designed to adjust the cylinder rotation force required to drive the piston rod upward, thereby adjusting the force required to open the door and reducing the probability of accidental door opening when the external force is small; when closing the door, the energy storage spring 4 pushes the piston rod 2 downward to make the piston rod 2 contact with the piston 3 again, and the width of the oil gap C is reduced to zero. The volume of the lower oil chamber A decreases with the downward movement of the piston rod 2, and the pressure increases. The oil can only flow from the lower oil chamber B to the upper oil chamber A through the oil channel 6. At this time, the valve needle 7 controls the oil flow through the oil channel 6 The cam 7 is actuated to move the piston rod 2 downwards, which in turn acts as a damping force on the door hinge, thereby providing a buffer for the downward movement of the piston rod 2 and a buffered closing of the door hinge. The shape and position of the valve needle 7 are designed to adjust the amount of oil flowing through the oil channel 6 during the downward movement of the piston rod 2. The downward movement speed of the piston rod 2 is adjusted to achieve the purpose of adjusting the door closing speed, thereby preventing sudden contact between the door leaf and the door frame and reducing the collision between the door leaf and the door frame. The piston 3 serves as a separating seal between the upper oil chamber A and the lower oil chamber, and also as a movable part connecting the upper oil chamber A and the lower oil chamber B when the piston rod 2 moves upwards, thereby achieving the movement characteristics of the piston rod 2 moving upwards quickly and buffering the downward movement, and simplifying the internal structure of the oil cylinder 1, making it easier to assemble and form, thereby reducing the cost of the buffer, and having a simple structure and high practicality.

[0024] Among them, the upper end of the piston rod 2 passes through the oil seal and extends into the oil-free chamber to cooperate with the energy storage spring 4. The lower end of the piston rod 2 extends into the oil chamber in a cross shape. The oil passage 6 is opened at the lower end of the piston rod 2, and is composed of an axial oil passage 61 arranged along the axial direction and a radial oil passage 62 arranged along the radial direction, which are cross-connected. The valve needle 7 is axially arranged in the oil chamber and extends into the axial oil passage 61. The valve needle 7 is a multi-stage variable diameter shape with a diameter decreasing from top to bottom. As shown in the accompanying drawings, an oil passage 6 is opened at the lower end of the piston rod 2, wherein an axial oil passage 61 is opened upward from the bottom surface of the piston rod 2, and a radial oil passage 62 is cross-connected with the axial oil passage 61 and radially penetrates the piston rod 2. The piston rod 2 does not avoid contact with the inside of the oil cylinder 1. The valve needle 7 extends into the axial oil passage 61 to limit the amount of oil flowing in the axial oil passage 61. The valve needle 7 is a multi-stage variable diameter shape. When the piston rod 2 moves downward, the piston rod 2 and the piston 3 are not separated, and no oil gap C is formed. Oil can only flow through the oil passage 6. As the piston rod 2 moves downward, the diameter of the valve needle 7 decreases from top to bottom, and the amount of oil flowing from the lower oil chamber B to the upper oil chamber A gradually increases, so that the damping force of the downward movement of the piston rod gradually decreases from large to small, so that the closing speed of the door hinge gradually increases from slow to fast, thereby gradually increasing the closing speed from slow to fast, forming a closing process that is slow first and then fast, forming an effective buffered door closing process.

[0025] The valve needle 7 is composed of multiple segments 71, with the diameters of the segments 71 decreasing from top to bottom. The diameter of the topmost segment 71 does not differ from the inner diameter of the axial oil passage 61 by more than 0.05 to 0.2 mm, and the diameter difference between adjacent segments 71 is 0.2 to 0.5 mm. The valve needle 7 is composed of multiple segments 71, with the topmost segment 71 having the largest diameter. This, in conjunction with the axial passage 61, minimizes the amount of oil flowing through the axial passage 61, creating the greatest damping force on the downward movement of the piston rod 2. As the piston rod 2 moves downward, the diameters of the segments 71 decrease, increasing the amount of oil flowing through the axial passage 61 and reducing the damping force on the downward movement of the piston rod 2. This causes the piston rod 2 to accelerate downward, resulting in a closing process that begins slowly and then accelerates.

[0026] Among them, the lower end of the oil cylinder 1 is sealed by a screw plug 8, and the screw plug 8 is threadedly inserted into the lower end cover of the oil cylinder 1 and sealed with the lower end cover of the oil cylinder. The lower end of the valve needle 7 is a spherical ball head end 72, and an arc groove 81 is provided on the top surface of the screw plug 8 to cooperate with the ball head end 72 and is arranged radially. The ball head end 72 extends into the arc groove 81. The number of segments 71 in the valve needle, the length of each segment 71, the diameter difference between adjacent segments 71, and the axial position of the screw plug 8 at the lower end of the oil cylinder 1 are designed to adjust the number of speed changes from slow to fast when the piston rod 2 moves downward and the speed change of the piston rod 2 each time the speed changes. The ball end 72 is positioned on the screw plug 8 by the circular arc groove 81 and will not move with the movement of the piston rod 2. Since the oil cylinder 1 drives the piston rod 2 to move by rotation, and the screw plug 8 will rotate synchronously with the oil cylinder 1, the circular arc groove 81 cooperates with the ball end 72, so that when the screw plug 81 rotates, the circular arc groove 81 rotates relative to the ball end 72, and the screw plug 81 can axially position the valve needle 7 without driving the valve needle 7 to rotate due to the rotation of the oil cylinder 1, so that the valve needle 7 is guaranteed to be stationary, thereby improving the reliability of the valve needle 7 when adjusting the oil flow through the oil channel 6. A sealing ring is hooped on the screw plug 8. The screw plug 8 is screwed into the sealing ring in the lower end cover of the oil cylinder and contacts the lower end cover to form a seal. The axial position of the screw plug 8 at the lower end of the oil cylinder 1 can be adjusted by rotating the thread. By adjusting the axial position of the screw plug 8, the axial position of the valve needle 7 can be adjusted, thereby adjusting the axial position of the uppermost segment 71 relative to the piston rod 2. According to the application scenario of the hinge closing hydraulic buffer and the closing speed requirement, the number of segments 71 in the valve needle, the length of each segment 71, the distance between adjacent segments 71 and the distance between adjacent segments are designed. The diameter difference of 71 and the axial position of the screw plug 8 at the lower end of the cylinder 1 are used to adjust the number of speed changes from slow to fast when the piston rod 2 moves downward and the speed change of the piston rod 2 each time the speed changes, thereby adjusting the closing speed, which can form a closing process in which the first half of the closing process is slow and the second half is fast. When the position of the screw plug 8 is adjusted to the lowest position, the axial position of the uppermost segment 71 is at the lowest position, so that the piston rod cooperates with the uppermost segment 71 almost throughout the entire downward movement, forming a closing process with a slower speed throughout the entire process.

[0027] Among them, the piston 3 includes a piston body 31 sleeved on the lower end of the piston rod 2 and a contact sealing ring 32 installed on the piston body 31. The contact sealing ring 32 is pressed against the inner wall of the cylinder 1. The piston body 31 is clearance-matched with the lower end of the piston rod 2 and the inner wall of the cylinder 1 respectively. The piston body 31 separates from the piston rod 2 as the piston rod 2 moves upward to form an oil gap C connecting the upper oil chamber A and the lower oil chamber B, and is pressed against the piston rod 2 as the piston rod 2 moves downward. The contact seal ring 32 is pressed against the inner wall of the oil cylinder 1. When the piston rod 2 moves upward, the pressure between the contact seal ring 32 and the oil cylinder 1 is tight, so that the piston 3 will not move upward synchronously with the piston rod 2, but will move relative to the piston rod 2, separating the two to form an oil gap C. The oil flow rate of the oil gap C is large, so that when the piston rod 2 moves upward, the oil in the upper oil chamber A can flow quickly to the lower oil chamber B, and the damping force formed is small. The piston rod 2 will move upward quickly, and because the energy storage spring 4 is compressed when the piston rod 2 moves upward, the speed of the upward movement of the piston rod 2 gradually decreases, forming a door opening process with a fast speed in the first half and a slow speed in the second half, preventing the edge of the door leaf from being squeezed and damaged due to excessive speed in the second half of the door opening. The door can be opened easily and damage to the door caused by excessive door opening thrust can be avoided.

[0028] Among them, the lower end of the piston rod 2 is provided with an annular groove 21, and an elastic circlip 9 is installed in the annular groove 21. The elastic circlip 9 is located below the piston body 31 and is axially separated from the piston body 31. The piston body 31 is in contact with the elastic circlip 9 as the piston rod 2 moves upward, and is separated from the piston rod 2 to form an oil gap C. The axial spacing between the piston body 31 and the elastic circlip 9 is 0.3~1 mm. Due to the restriction of the contact sealing ring 32, when the piston rod 2 moves upward, the piston 3 will first stay in the original position, and the elastic retaining ring 9 will move upward synchronously with the piston rod, and resist the piston 2, so that the piston 3 and the piston rod 2 are separated to form an oil gap C. The piston rod continues to move upward and will pull the piston 2 upward synchronously through the elastic retaining ring 9. At this time, the oil gap C remains unchanged. The oil in the upper oil chamber A can quickly flow to the lower oil chamber B through the oil gap C, the gap between the piston rod 2 and the inner wall of the cylinder 1, and the gap between the piston rod 2 and the piston body 31, so that the piston rod 2 moves upward quickly. The piston rod 2 compresses the energy storage spring 4 upward, and the rising speed changes from fast to slow. When the upward speed of the piston rod 2 drops to zero, the compressed energy storage spring 4 pushes the piston rod 2 to move downward. The downward movement of the piston rod 2 will drive the cylinder 1 to rotate, forming the closing of the door hinge.

[0029] The piston body 31 is provided with an inwardly recessed annular positioning groove 311, into which the contact seal 32 is clamped. Grease is applied to the annular positioning groove 311. When the piston rod 2 moves upward, the piston rod body 31 contacts the circlip 9, and the piston rod 2 drives the piston 3 upward synchronously through the circlip 9. The contact seal 32 also rubs against the cylinder 2. When the piston rod 2 moves downward, the piston rod 2 contacts the piston 3, pushing the piston 3 downward synchronously. The contact seal 32 also rubs against the cylinder 2. To reduce friction between the two and reduce wear on the contact seal 32, a certain amount of grease is applied to the positioning groove 311 to reduce wear on the contact seal 32 and extend its service life.

[0030] The upper end of the piston rod 2 is fixed with a radially arranged crossbar 22. The end of the crossbar 22 extends from the oil cylinder 1. The oil cylinder 1 has a spiral hole 10 for the end of the crossbar to extend and move. When the door hinge is unfolded, it drives the oil cylinder 1 to rotate. The rotation of the oil cylinder 1 causes the end of the crossbar 22 to move in the spiral hole 10, causing the piston rod 2 to move upward along the threaded hole 10 to accommodate the movement of the crossbar 22 along the spiral hole 10. When the energy storage spring 4 pushes the piston rod 2 downward, the piston rod 2 will move downward along the spiral hole 10, driving the oil cylinder 1 to rotate and close the door hinge. The cooperation between the crossbar 11 and the spiral hole 10 enables the rotation of the oil cylinder 1 to drive the upward movement of the piston rod 2, and the downward movement of the piston rod 2 to drive the rotation of the oil cylinder 1. During the rotation of the door hinge, the piston rod 2 moves in the oil cylinder 1, forming a hydraulic buffer for the opening and closing of the door.

[0031] Among them, the oil cylinder 1 is equipped with a guide column 11 that cooperates with the upper end of the piston rod 2 and a spring matching column 12 that cooperates with the energy storage spring 4. The lower end of the guide column 11 is provided with a matching groove 111, and the upper end of the piston rod 2 extends into the matching groove 111. The upper end of the guide column 11 is spherical in shape and contacts the lower end of the spring matching column 12. The spring matching column 12 extends into the energy storage spring 4. The lower end of the energy storage spring 4 is against the spring matching column 12, and the upper end is against the upper end of the oil cylinder 1. The guide column 11 is matched with the inner wall of the oil cylinder 1, and pushes the spring matching column 12 to compress the energy storage spring 4 as the piston rod 2 moves upward. The length of the guide column 12 is designed, and the length of the energy storage spring 4 is adjusted, thereby designing the stiffness of the energy storage spring 4. The upper end of the guide column 11 is spherical, which reduces the friction between the piston rod 1 and the spring matching column 12 when the piston rod 1 rotates. Since the piston 3 and the piston rod 2 are separated to form an oil gap C when the piston rod 2 moves upward, the oil flow rate of the oil gap C is large, so that the oil damping force on the piston rod 2 when it moves upward is very small, and the upward movement of the piston rod 2 will compress the energy storage spring 4. The greater the stiffness of the energy storage spring 4, the greater the force required for the piston rod 2 to move upward to compress the energy storage spring 4. The upward movement of the piston rod 2 is driven by the rotation of the oil cylinder 1, and the rotation of the oil cylinder 1 is driven by the external force pushing the door to open the door hinge. Therefore, the greater the stiffness of the energy storage spring 4, the greater the external force required to open the door hinge. By adjusting the stiffness of the energy storage spring 4, the The external force required for opening the door is generated by forming an oil gap C between the piston 3 and the piston village 2. When the piston rod moves upward, the oil is quickly and abundantly passed through, making it easier to open the door. The force required for opening the door is adjusted by adjusting the stiffness of the energy storage spring 4. While ensuring effort saving, the door can be prevented from being easily pushed open when the external force is very small, and the probability of accidentally opening the door when the external force is small is reduced. In the initial state when the piston rod has not moved upward, the energy storage spring 4 is in a free state. The energy storage spring 4 is only compressed when the piston rod 2 moves upward. The longer the guide column 11 is, the longer the energy storage spring 4 will be, and its stiffness will be smaller. Therefore, the stiffness of the energy storage spring 4 can be adjusted by adjusting the length of the guide column 11.

[0032] The inner wall of the oil cylinder 1 has an annular stepped surface 13 located above the oil seal 5. A spring seat 14 is provided on the top surface of the oil seal 5. An oil seal spring 15 is sandwiched between the spring seat 14 and the annular stepped surface 12. The upper end of the piston rod 2 passes through the oil seal 5, the spring seat 14, and the oil seal spring 15, and engages with the guide post 10. The spring seat 14 and the oil seal spring 15 respectively engage with the piston rod. The oil seal spring 15 and the spring seat 14 elastically position the oil seal 5. When the piston rod 2 moves upward and contacts the oil seal 5, the oil seal 5 is pushed upward by the piston rod 2, compressing the oil seal spring 15. This decelerates the upward movement of the piston rod 2, increases the door opening angle, and prevents damage to the door hinge caused by excessive door opening speed. Once the door is fully opened, the oil seal spring 15 and the energy storage spring 4 push the piston rod 2 downward, causing the piston rod 2 to quickly contact the piston 3. The width of the oil gap C is reduced to zero. Once the oil seal spring 15 returns to its free state, the oil seal is protected.

[0033] The above fully describes the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the embodiments described are only part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. Design method for a hydraulic buffer for hinged door closing, comprising a cylinder, wherein the cylinder houses a piston rod that moves axially with the rotation of the cylinder, a piston that seals against the inner wall of the cylinder, an energy storage spring that is compressed with the upward movement of the piston rod, and an oil seal that seals against both the piston rod and the inner wall of the cylinder, the oil seal dividing the inner cavity of the cylinder into an oil-free chamber and an oil-filled chamber located below the oil-free chamber, the piston being located in the oil-filled chamber, the energy storage spring being located in the oil-free chamber, and the piston dividing the oil-filled chamber into an upper oil chamber and a lower oil chamber, characterized in that: An oil passage connecting the upper oil chamber and the lower oil chamber is provided on the piston rod, a valve needle capable of adjusting the amount of oil flowing through the oil passage is installed in the oil cylinder, the piston is movably mounted on the piston rod, and the piston is separated from the piston rod as the piston rod moves upward, forming an oil gap connecting the upper oil chamber and the lower oil chamber, the valve needle adjusts the amount of oil flowing through the oil passage as the piston rod moves downward, the stiffness of the energy storage spring is designed to adjust the cylinder rotation force required to drive the piston rod to move upward, and the shape and position of the valve needle are designed to adjust the speed of the downward movement of the piston rod; The piston comprises a piston body sleeved on the lower end of the piston rod and a contact sealing ring mounted on the piston body. The contact sealing ring is pressed against the inner wall of the oil cylinder. The piston body is clearance-matched with the lower end of the piston rod and the inner wall of the oil cylinder respectively. The piston body separates from the piston rod as the piston rod moves upward to form an oil gap connecting the upper oil chamber and the lower oil chamber, and is pressed against the piston rod as the piston rod moves downward. The lower end of the piston rod is provided with an annular groove, in which an elastic circlip is installed. The elastic circlip is located below the piston body and is axially separated from the piston body. As the piston rod moves upward, the piston body abuts against the elastic circlip and is separated from the piston rod to form an oil gap. The axial spacing between the piston body and the elastic circlip is 0.3 to 1 mm. An inwardly recessed annular positioning groove is provided on the piston body, a contact sealing ring is clamped in the annular positioning groove, and lubricating grease is coated in the annular positioning groove.

2. The design method of the hinged door hydraulic buffer according to claim 1, characterized in that: The upper end of the piston rod passes through the oil seal and extends into the oil-free chamber to cooperate with the energy storage spring. The lower end of the piston rod extends into the oil chamber in a cross shape. The oil passage is opened at the lower end of the piston rod, and is composed of an axial oil passage arranged along the axial direction and a radial oil passage arranged along the radial direction, which are cross-connected. The valve needle is arranged axially in the oil chamber and extends into the axial oil passage. The valve needle is a multi-stage variable diameter shape with a diameter decreasing from top to bottom.

3. The design method of the hinged door hydraulic buffer according to claim 2, characterized in that: The valve needle is composed of multiple segments, the diameters of which decrease from top to bottom. The difference between the diameter of the topmost segment and the inner diameter of the axial oil channel does not exceed 0.05-0.2 mm, and the difference in diameters between adjacent segments is 0.2-0.5 mm.

4. The design method of a hinged door hydraulic buffer according to claim 2, characterized in that: The lower end of the oil cylinder is sealed by a screw plug, the screw plug thread is fitted into the end cover of the lower end of the oil cylinder and is sealed with the end cover of the lower end of the oil cylinder. The lower end of the valve needle is a spherical ball head end, and an arc groove is provided on the top surface of the screw plug that cooperates with the ball head end and is arranged radially. The ball head end extends into the arc groove. The number of segments in the valve needle, the length of each segment, the diameter difference between adjacent segments, and the axial position of the screw plug at the lower end of the oil cylinder are designed to adjust the number of speed changes from slow to fast when the piston rod moves downward and the speed change of the piston rod each time the speed changes.

5. The design method of the hinge door hydraulic buffer according to claim 2, characterized in that: The upper end of the piston rod is fixed with a cross bar arranged in a radial direction, and the end of the cross bar passes through the oil cylinder. The oil cylinder is provided with a spiral hole for the end of the cross bar to pass through and move.

6. The design method of a hinged door hydraulic buffer according to claim 1, characterized in that: The oil cylinder is equipped with a guide column that cooperates with the upper end of the piston rod and a spring matching column that cooperates with the energy storage spring. A matching groove is opened at the lower end of the guide column, and the upper end of the piston rod extends into the matching groove. The upper end of the guide column is spherical and contacts with the lower end of the spring matching column. The spring matching column extends into the energy storage spring. The lower end of the energy storage spring is against the spring matching column, and the upper end is against the upper end of the oil cylinder. The guide column is matched with the inner wall of the oil cylinder and pushes the spring matching column to compress the energy storage spring as the piston rod moves upward. The length of the guide column is designed, the length of the energy storage spring is adjusted, and the stiffness of the energy storage spring is designed.

7. The design method of a hinged door hydraulic buffer according to claim 6, characterized in that: The inner wall of the oil cylinder has an annular step surface located above the oil seal, a spring seat is provided on the top surface of the oil seal, an oil seal spring is sandwiched between the spring seat and the annular step surface, the upper end of the piston rod passes through the oil seal, the spring seat and the oil seal spring and cooperates with the guide column, and the spring seat and the oil seal spring are respectively clearance-matched with the piston rod.

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