A hinge for preventing door pinch

Abstract

This invention discloses a hinge for preventing hands from being pinched when closing a door, comprising a fixed hinge, a rotating hinge, a hinge shaft connecting the fixed hinge and the rotating hinge, and a damper disposed on the rotating hinge. The damper has a damping rod that can only be pushed by overcoming the damping force. A force converter is disposed between the damping rod and the fixed hinge, which is used to: convert the damping force F01 of the damper into an impedance force F that resists the rotational inertia force of the door closing, thereby increasing the impedance force F in the initial stage and bearing the component force F2 that increases the impedance force F, thereby weakening the component force F2.

Description

Technical Field

[0001] This invention relates to a hinge for preventing hands from being pinched when closing doors, belonging to the field of hinge technology. Background Technology

[0002] Doors that are frequently opened and closed and are quite heavy (such as the iron door between the locomotive cab and the engine room) can cause significant inertial force when closed carelessly by jerking the door in noisy environments or when the person is not paying attention. This can easily result in the person's hand being pinched between the door edge and the door frame. To address this problem, various hinges have been developed to resist the inertial force of door rotation when closing. The basic principle is to apply resistance to the door as it approaches closure, with this resistance increasing over time. This reduces the force and speed at which the door edge approaches the door frame, allowing the person to quickly retract their fingers when they feel pressure, or minimizing the risk of injury even if pressure is applied.

[0003] However, these types of hinges generally have the following problems: On the one hand, due to the limitation of installation space and considerations of aesthetics, the size of these hinges cannot be too large. This results in smaller load-bearing components, insufficient bending strength, and a fragile overall load-bearing structure, which is insufficient to resist the inertial force of a door that closes quickly and is heavy. They are generally only suitable for smaller and lighter doors. On the other hand, these hinges provide resistance in a single form, mostly using only elastic components for pressure buffering. When the components are thin and weak, they cannot provide a sufficiently large buffering force.

[0004] In addition, these hinges should not be given too much resistance, as this would make the door difficult to close. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to make the hinge strong enough to resist the rotational inertial force generated by a door with a fast closing speed and large self-weight during the closing process, under the premise of limited size, so as to prevent injury to the hand by pinching, while ensuring that the door can be closed smoothly.

[0006] To address the above problems, the technical solution proposed by this invention is as follows: A hinge for preventing hands from being pinched when closing a door includes a fixed hinge, a rotating hinge, a hinge shaft that hinges the fixed hinge and the rotating hinge together, and a damper provided on the rotating hinge. The damper has a damping rod that can only be pushed by overcoming a damping force. A force converter is provided between the damping rod and the fixed hinge, which is used to: convert the damping force F01 of the damper into a resistance force F that resists the rotational inertia force of the door closing, thereby increasing the resistance force F in the initial stage and bearing the component force F2 that increases the resistance force F, thus making the component force F2 change from strong to weak.

[0007] The damper is located on the outer side of the rotating hinge, with the outer end of its damping rod facing the hinge shaft. A through groove is provided on the rotating hinge between the hinge shaft and the damper. The force converter is located on the inner side of the rotating hinge and contacts the outer end of the damping rod and the inner side of the fixed hinge through the through groove.

[0008] The force converter is a fan-shaped body with a central hole. At the intersection of the first and second side surfaces on both sides of the fan surface with the two ends of the outer arc surface, there are pressure angle one and pressure angle two, respectively. Supports are provided on both sides of the through groove on the inner side of the rotating hinge, and a rotating shaft is installed between the two supports. The force converter is installed on the rotating shaft between the two supports through the central hole. Its pressure angle one is located on the outer side of the rotating hinge through the through groove and keeps in contact with the outer end of the damping rod. Its pressure angle two is located on the inner side of the rotating hinge and can contact the fixed hinge and be pressed.

[0009] When the pressure angle 2 is in contact with the inner surface of the fixed hinge and is compressed, the line L connecting the contact point O and the center of the circular hole has an angle α with the inner surface of the fixed hinge on the side away from the hinge axis, such that the angle α is greater than 50° and less than 70°. The resistance force F of the fixed hinge on the pressure angle 2 forms a component force F2 pointing towards the center of the circular hole and a tangential component force F1 along the outer arc surface of the force converter at the contact point O. The component force F1 is the reaction force of the damping force F01.

[0010] Stop posts are provided on both sides of the force converter located outside the rotating piston. When the force converter rotates inward, it contacts the outer side of the rotating hinge to prevent the force converter from continuing to rotate and ensure that the maximum angle α is less than 70°.

[0011] Pulleys are installed at the first and second pressure angles of the force converter.

[0012] The damper is a hydraulic damper, which includes a cylinder body, a hydraulic cylinder chamber for filling with damping fluid, a piston connected to a damping rod in the hydraulic cylinder chamber, and the piston divides the hydraulic cylinder chamber into a front chamber and a rear chamber, with a damping flow channel between the front chamber and the rear chamber.

[0013] The damping flow channel includes an inner wall section located within the cylinder wall and a flow regulation section located at the rear end of the rear cavity, as well as a connecting section between the flow regulation section and the inner wall section 25. The flow regulation section is an axially arranged straight section, the end of which is a tapered hole with a rear diameter larger than the front diameter. Behind the tapered hole is a bolt hole with its front end coaxially connected to the tapered hole and its rear end leading to the outside of the damper. An adjusting bolt is provided in the bolt hole. The front end of the adjusting bolt has a tapered body with a front diameter smaller than the rear diameter. The tapered body of the adjusting bolt moves back and forth within the tapered hole of the flow regulation section, which can adjust the size of the fluid flow gap between the tapered body and the wall of the tapered hole.

[0014] The hydraulic cylinder chamber has a pressure relief section located at the rear of the front chamber. The diameter of the pressure relief section is larger than the piston diameter. When the door is close to closing and the piston is in the pressure relief section, the damping fluid in the rear chamber directly enters the front chamber through the gap between the piston and the inner wall of the pressure relief section, thereby weakening the damping force F01.

[0015] A return spring is provided between the base of the rear chamber and the piston to return the piston to its forward position. Beneficial effects

[0016] 1. Because the force converter can increase the initial resistance force F and bear the component force F2 that increases the resistance force F, it can not only obtain effective resistance when the door rotates at its fastest speed and the inertial force is the greatest, so that the door rotation speed decreases within a shorter rotation stroke, but also share part of the impact load for the damper, so that the hinge of the same size structure can withstand the large inertial force impact of a heavy door that rotates faster when closed. 2. Due to the force converter's ability to reduce the component force F2 from strong to weak and the damper's internal pressure relief mechanism, the resistance force F can be reduced to a minimum at the last moment before the door closes, allowing the door to close smoothly. 3. Because the return spring is in a compressed state after the door is closed, it provides elastic assistance when opening the door, making it easier to open the door. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the installation of the hinge described in Embodiment 1 on the door and door frame; Figure 2 This is a three-dimensional schematic diagram of the hinge described in Embodiment 1; Figure 3 This is a schematic diagram of the hinge described in Embodiment 1 after the cylinder body has been removed; Figure 4 This is a cross-sectional schematic diagram of the hinge described in Embodiment 1, showing the state of the hinge when the door is closed; Figure 5 The diagram shows the force analysis of the door rotating when the hinge described in Embodiment 1 provides resistance force F to the door. The diagram shows the initial state of the door under resistance force F, at which angle a is the largest, and the values ​​of resistance force F and component force F2 are the largest. The arc arrow A in the diagram indicates the direction of forced rotation of the force converter when the door is closed. Figure 6 The diagram shows the force analysis of the door being closed by the hinge described in Example 1, which provides resistance force F to the door. The diagram shows the middle state of the door under resistance force F, at which point the included angle α becomes smaller and the values ​​of resistance force F and component force F2 decrease. Figure 7The diagram shows the force analysis of the door being closed by the hinge described in Example 1, which provides resistance force F to the door. The diagram shows the final state of the door under resistance force F. At this time, the included angle α is zero, the direction of resistance force F is perpendicular to the line L connecting the centers of the circular holes, the component force F2 disappears, and the resistance force F is the component force F1. The component force F1 is also the reaction force of the damping force F01. Figure 8 for Figure 4 A partial schematic diagram; Figure 9 This is a partial schematic diagram of the cross-sectional view of the hinge described in Embodiment 2; Figure 10 This is a partial schematic diagram of the cross-sectional view of the hinge described in Embodiment 3.

[0018] In the diagram: 1. Rotating hinge; 101. Through slot; 2. Fixed hinge; 3. Hinge shaft; 4. Damper; 41. Cylinder body; 42. Hydraulic cylinder chamber; 421. Front chamber; 422. Rear chamber; 423. Pressure relief section; 43. Piston; 44. Damping rod; 45. Damping flow channel; 451. Inner wall section; 452. Flow regulation section; 4521. Conical hole; 453. Connecting section; 46. Bolt hole; 47. Adjusting bolt; 471. Conical body; 48. Fluid flow gap; 49. Return spring; 5. Force converter; 50. Central hole; 51. Pressure angle one; 52. Pressure angle two; 53. Side surface one; 54. Side surface two; 55. Outer arc surface; 56. Stop post; 57. Pulley; 58. Support; 59. Rotating shaft; 6. Door; 7. Door frame. Detailed Implementation

[0019] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1

[0020] like Figure 1-7As shown, a hinge for preventing hands from being pinched when closing a door includes a fixed hinge 2, a rotating hinge 1, a hinge shaft 3 that hinges the fixed hinge 2 and the rotating hinge 1, and a damper 4 provided on the rotating hinge 1. The damper 4 has a damping rod 44 that can only be pushed by overcoming the damping force. A force converter 5 is provided between the damping rod 44 and the fixed hinge 2. The force converter 5 is used to: convert the damping force F01 of the damper 4 into an impedance force F that resists the rotational inertia force of the door 6 when closing, so that the initial impedance force F increases and bears the component force F2 that increases the impedance force F, so that the component force F2 changes from strong to weak. In application, the fixed hinge 2 is fixed to the door frame 7, and the rotating hinge 1 is installed on the door 6. During the closing process, when the edge of the door 6 is still a certain distance from the door frame 25, the force converter 5, the damping rod 44, and the fixed hinge 2 come into contact simultaneously. As the door 6, together with the rotating hinge 1, continuously approaches the fixed hinge 2, the fixed hinge 2 continuously applies a pushing force to the damping rod 44 through the force converter 5, forcing the damping rod 44 to overcome the damping force F01 and retract into the damper 4. At the same time, the damping force F01 acts on the fixed hinge 2 through the force converter 5, forming an impedance force F in the form of a reaction force that resists the rotational inertia force of the closing door 6. Because the force converter 5 can increase the initial resistance force F and withstand the component force F2 that increases the resistance force F, it can not only obtain effective resistance when the door 6 rotates at its fastest speed and has the greatest inertial force, thus reducing the rotation speed of the door 6 within a shorter rotation stroke, but also allow the damper 4 to share part of the impact load, enabling the hinge of the same size structure to withstand the large inertial force impact of the door 6 when it is heavy and rotates quickly when closing. Because the force converter 5 can weaken the component force F2, when the door 6 is close to closing and the rotation speed of the door 6 is already very slow, it can reduce the resistance force F, making the door 6 easier to close.

[0021] The following are further improvements: like Figure 3 , 4 As shown, the damper 4 is located on the outer side of the rotating hinge 1, with the outer end of its damping rod 44 facing the hinge shaft 3. A through groove 101 is provided on the rotating hinge 1 between the hinge shaft 3 and the damper 4. The force converter 5 is located on the inner side of the rotating hinge 1 and contacts the outer end of the damping rod 44 and the inner side of the fixed hinge 2 through the through groove 101. The force converter 5 is a fan-shaped body with a central hole 50. At the intersection of the first side surface 53 and the second side surface 54 on both sides of the fan surface with the two ends of the outer arc surface 55, there are pressure angle 1 51 and pressure angle 2 52 respectively. Supports 58 are provided on both sides of the through groove 101 on the inner side of the rotating hinge 1, and a rotating shaft 59 is installed between the two supports 58. The force converter 5 is installed on the rotating shaft 59 between the two supports 58 through the central hole 50 and can rotate around the rotating shaft. Its pressure angle 1 51 is located outside the rotating hinge 1 through the through groove 101 and keeps in contact with the outer end of the damping rod 44. Its pressure angle 2 52 is located inside the rotating hinge 1 and can contact the fixed hinge 2 and be pressed.

[0022] like Figure 5-7 As shown, when the pressure angle 52 is in contact with the inner surface of the fixed hinge 2 and is under pressure, the line L connecting the contact point O and the center of the central hole 50 forms an angle α with the inner surface of the fixed hinge 2 on the side away from the hinge axis 3, such that the angle α is greater than 50° and less than 70°, for example, 50°, 55°, 60°, 65°, or 70°. The resistance force F of the fixed hinge 2 on the pressure angle 52 forms a component force F2 pointing towards the center of the central hole 50 and a tangential component force F1 at the contact point O along the outer arc surface 55 of the force converter 5. The component force F1 is the reaction force of the damping force F01.

[0023] It should be noted here that the pressure exerted by the fixed hinge 2 on the pressure angle 52 is actually the resistive force F that resists the rotational inertia of the door 6 by the fixed hinge 2. Its direction is the normal direction perpendicular to the inner surface of the fixed hinge 2. The resistive force F forms a component force F2 pointing towards the center of the circular hole 50, which is the component force F2 that increases the resistive force F mentioned above. The increase in the resistive force F by the component force F2 is actually determined by the structural form of the force converter 5 as described above. According to the principle of force decomposition, this can be expressed in reverse. The resistive force F forms a component force F2 pointing towards the center of the circular hole 50; the component force F1 is the reaction force of the damping force F01, which is a lever with equal arm length and common axis of rotation between the circular hole 50 and the first pressure angle 51 and between the circular hole 50 and the second pressure angle 52 on the fan-shaped force converter 5. The damping force F01 is transmitted from the first pressure angle 51 to the second pressure angle 52 and acts on the fixed hinge 2, forming a reaction force of equal magnitude and opposite direction of the fixed hinge 2 on the second pressure angle 52, i.e., component force F1.

[0024] As can be seen from the above, the resistance force F is the resultant force of the component forces F1 and F2.

[0025] like Figure 5 As shown, during the closing process, when the edge of door 6 is still a certain distance from door frame 25, at the moment when the force converter 5's pressure angle 52 contacts and is pressed against the inner side of fixed hinge 2, the included angle α is at its maximum, the component force F2 is at its maximum, and the resistance force F is also at its maximum. This results in door 6 experiencing the maximum resistance force F when it has the maximum inertial force, which can reduce the rotational speed of door 6 within a shorter rotational stroke. The component force F2 towards the center of force converter 5 is ultimately borne by the rotating shaft 59, and does not need to be borne by the pressure component inside damper 4.

[0026] like Figure 6 As shown, as door 6 continues to rotate, the pressure converter 5 of the fixed hinge 2 rotates, the included angle α gradually decreases, the value of the component force F2 decreases, and the resistance force F also decreases accordingly, but the rotational speed of door 6 continues to decrease.

[0027] like Figure 7As shown, when the door 6 rotates until the connecting line L coincides with the inner side of the fixed hinge 2, the direction of the resistance force F is perpendicular to the connecting line L. The included angle α and the component force F2 no longer exist. The resistance force F is the component force F1, which means that the resistance force F is completely provided by the reaction force of the damping force F01. At this time, the door 6 almost stops rotating and will no longer cause injury to the hand. Thus, the process of the force converter 5 making the resistance force F decrease from large to small has fully met the design requirements.

[0028] like Figure 2 , 3 As shown, stop posts 56 are provided on both sides of the force converter 5 located outside the rotating piston 43. When the force converter 5 rotates to the inside of the rotating hinge 1, it contacts the outer side of the rotating hinge 1 to prevent the force converter 5 from continuing to rotate, ensuring that the maximum angle α is less than 70°.

[0029] like Figure 2 As shown, during the process of the force converter 5 rotating under pressure, the pressure angle 1 51 and pressure angle 2 52 will slide on the end face of the damping rod 44 and the inner side of the fixed hinge 2, respectively. In order to ensure smooth sliding, pulleys 57 are provided at the pressure angle 1 51 and pressure angle 2 52 of the force converter 5, respectively. It can also be seen that the contact point O between the inner side of the fixed hinge 2 and the pressure angle 2 52 of the force converter 5 is actually the contact point between the inner side of the fixed hinge 2 and the pulley 57 at the pressure angle 2 52.

[0030] like Figure 4 As shown, preferably, the damper 4 is a hydraulic damper, which includes a cylinder body 41. The cylinder body 41 has a hydraulic cylinder chamber 42 for filling with damping fluid. The hydraulic cylinder chamber 42 has a piston 43 connected to the damping rod 44. The piston 43 divides the hydraulic cylinder chamber 42 into a front chamber 421 and a rear chamber 422. A damping flow channel 45 is provided between the front chamber 421 and the rear chamber 422. When the piston 43 is pushed into the rear chamber 422, the damping fluid in the rear chamber 422 enters the front chamber 421 through the damping flow channel 45. When the piston 43 is reset to the front chamber 421, the damping fluid in the front chamber 421 enters the rear chamber 422 through the damping flow channel 45.

[0031] like Figure 8As shown, the damping flow channel 45 further includes an inner wall section 451 disposed within the cylinder wall and a flow regulating section 452 disposed at the tail end of the rear cavity 422, as well as a connecting section 453 between the flow regulating section 452 and the inner wall section 25. The flow regulating section 452 is an axially arranged straight section, the end of which is a tapered hole 4521 with a rear diameter larger than the front diameter. The tapered hole 4521 has a bolt hole 46 with its front end coaxially connected to the tapered hole 4521 and its rear end leading to the outside of the damper 4. An adjusting bolt 47 is disposed in the bolt hole 46. The front end of the adjusting bolt 47 has a tapered body 471 with a front diameter smaller than the rear diameter. The tapered body 471 of the adjusting bolt 47 moves back and forth within the tapered hole 4521 of the flow regulating section 452, which can adjust the size of the fluid flow gap 48 between the tapered body 471 and the wall of the tapered hole 4521. In this way, the magnitude of the inertial force can be estimated based on the self-weight of the door 6, and the adjusting bolt 47 can be turned to obtain the appropriate damping force.

[0032] like Figure 3 , 4 As shown, a return spring 49 is provided between the base of the rear cavity 422 and the piston 43 to reset the piston 43 forward. As mentioned above, the pressure angle 51 is in contact with the outer end of the damping rod 44 through the through groove 101 on the outside of the rotating hinge 1. That is, when the pressure angle 52 of the force converter 5 disengages from the fixed hinge 2 after the door is opened, the return spring 49 can push the piston 43 and its damping rod 44 forward to reset. The front end of the damping rod 44 abuts against the pressure angle 51 of the force converter 5 to make the force converter 5 rotate until the stop post 56 contacts the rotating hinge 1.

[0033] It should be noted that: on the one hand, the return spring 49 has elastic force, and the resistance force F actually includes this elastic force. However, in the closing of heavy doors, the elastic resistance force provided by the return spring 49 is relatively weak, and its resistance effect is not significant. On the other hand, after the door is closed, the return spring 49 is in a compressed state, which makes the door opening have elastic assistance, and the door 6 can be opened more easily. Example 2

[0034] like Figure 9 As shown, this is a further improvement of Embodiment 1. The hydraulic cylinder chamber 42 has a pressure relief section 423 located at the rear of the front chamber 421. The diameter of the pressure relief section 423 is larger than the diameter of the piston 43. When the door 6 is close to closing and the piston 43 is located in the pressure relief section 423, the damping fluid in the rear chamber 422 directly enters the front chamber 421 through the gap between the piston 43 and the inner wall of the pressure relief section 423, which weakens the damping force F01 and allows the door 6 to close easily. Example 3

[0035] like Figure 10 As shown, the difference between this embodiment and the previous one is that the damping channel 45 is located on the piston 43, which makes the channel layout relatively simple.

[0036] The above embodiments are only used to describe the present invention more clearly, and should not be regarded as limiting the scope of protection covered by the present invention. Any equivalent modifications should be regarded as falling within the scope of protection covered by the present invention.

Claims

1. A hinge for preventing hand pinching when closing a door, comprising a fixed hinge (2), a rotating hinge (1), a hinge shaft (3) hingedly connecting the fixed hinge (2) and the rotating hinge (1), and a damper (4) provided on the rotating hinge (1), the damper (4) having a damping rod (44) that can be pushed against damping force, characterized in that: A force converter (5) is provided between the damping rod (44) and the fixed hinge (2) for: converting the damping force F01 of the damper (4) into the resistance force F of the closing rotational inertia force of the impedance door (6), so that the resistance force F in the initial stage increases and bears the component force F2 that increases the resistance force F, so that the component force F2 changes from strong to weak.

2. The hinge for preventing hand pinching when closing a door according to claim 1, characterized in that: The damper (4) is located on the outer side of the rotating hinge (1), with the outer end of its damping rod (44) facing the hinge shaft (3). A through groove (101) is provided on the rotating hinge (1) between the hinge shaft (3) and the damper (4). The force converter (5) is located on the inner side of the rotating hinge (1) and contacts the outer end of the damping rod (44) and the inner side of the fixed hinge (2) through the through groove (101).

3. The hinge for preventing hand pinching when closing a door according to claim 2, characterized in that: The force converter (5) is a fan-shaped body with a central hole (50). At the intersection of the first side surface (53) and the second side surface (54) on both sides of the fan surface with the two ends of the outer arc surface (55), there are pressure angle one (51) and pressure angle two (52) respectively. Supports (58) are provided on both sides of the through groove (101) on the inner side of the rotating hinge (1), and a rotating shaft (59) is installed between the two supports (58). The force converter (5) is installed on the rotating shaft (59) between the two supports (58) through the central hole (50). Its pressure angle one (51) is in contact with the outer end of the damping rod (44) on the outside of the rotating hinge (1) through the through groove (101), and pressure angle two (52) is located on the inner side of the rotating hinge (1) and can contact the fixed hinge (2) and be pressed.

4. The hinge for preventing hand pinching when closing a door according to claim 3, characterized in that: When the pressure angle (52) is in contact with the inner side of the fixed hinge (2) and is compressed, the line L connecting the contact point O and the center of the circular hole (50) has an angle a with the inner side of the fixed hinge (2) away from the hinge axis (3), such that the angle a is greater than 50° and less than 70°. The resistance force F of the fixed hinge (2) on the pressure angle (52) forms a component force F2 pointing to the center of the circular hole (50) and a tangential component force F1 of the contact point O along the outer arc surface (55) of the force converter (5). The component force F1 is the reaction force of the damping force F01.

5. The hinge for preventing hand pinching when closing a door according to claim 4, characterized in that: Stop posts (56) are provided on both sides of the force converter (5) located outside the rotating piston (43). When the force converter (5) rotates to the inside of the rotating hinge (1), it contacts the outer side of the rotating hinge (1) to prevent the force converter (5) from continuing to rotate and ensure that the maximum angle of the included angle a is less than 70°.

6. The hinge for preventing hand pinching when closing a door according to claim 3, characterized in that: Pulleys (57) are provided at the pressure angle one (51) and pressure angle two (52) positions of the force converter (5).

7. The hinge for preventing hand pinching when closing a door according to claim 1, characterized in that: The damper (4) is a hydraulic damper, which includes a cylinder body (41). The cylinder body (41) is provided with a hydraulic cylinder chamber (42) for filling damping fluid. The hydraulic cylinder chamber (42) is provided with a piston (43) connected to the damping rod (44). The piston (43) divides the hydraulic cylinder chamber (42) into a front chamber (421) and a rear chamber (422). A damping flow channel (45) is provided between the front chamber (421) and the rear chamber (422).

8. The hinge for preventing hand pinching when closing a door according to claim 7, characterized in that: The damping flow channel (45) includes an inner wall section (451) located within the cylinder wall and a flow regulating section (452) located at the tail end of the rear cavity (422), as well as a connecting section (453) between the flow regulating section (452) and the inner wall section 25. The flow regulating section (452) is an axially arranged straight section, and its final section is a tapered hole (4521) with a rear diameter larger than the front diameter. The tapered hole (4521) has a front end that is coaxially connected to the tapered hole (4521). The rear end leads to the bolt hole (46) outside the damper (4). An adjusting bolt (47) is provided in the bolt hole (46). The front end of the adjusting bolt (47) has a cone (471) with a front diameter smaller than the rear diameter. The cone (471) of the adjusting bolt (47) moves back and forth in the cone hole (4521) of the flow regulating section (452), which can adjust the size of the liquid flow gap (48) between the cone (471) and the wall of the cone hole (4521).

9. The hinge for preventing hand pinching when closing a door according to claim 7, characterized in that: The hydraulic cylinder chamber (42) has a pressure relief section (423) located behind the front chamber (421). The diameter of the pressure relief section (423) is larger than the diameter of the piston (43). When the door (6) is close to closing and the piston (43) is located in the pressure relief section (423), the damping fluid in the rear chamber (422) directly enters the front chamber (421) through the gap between the piston (43) and the inner wall of the pressure relief section (423), thereby weakening the damping force F01.

10. The hinge for preventing hand pinching when closing a door according to claim 7, characterized in that: A return spring (49) is provided between the base of the rear cavity (422) and the piston (43) to reset the piston (43) forward.

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