Rotary damper

Abstract

To avoid contact between a valve and a housing.SOLUTION: The rotary damper includes: vanes (22) protruding from a shaft (21); passages (40) respectively formed at the vanes (22); and a valve (50) which prevents back flow of an oil in the passages (40). The shaft (21) has: a hole (21a) having a depth in an axial direction; and grooves (21b) penetrating through a peripheral wall of the hole (21a). The passage (40) is formed at a position away from an outer edge of the vane (22), and the valve (50) has: an engagement part (51) which is inserted into the hole (21a) and engages with the peripheral wall of the hole (21a); valve parts (52) which respectively open or close the passages (40); and intermediate parts (53) each of which is located between the engagement part (51) and the valve part (52) and inserted into the groove (21b).SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a rotary damper.

Background Art

[0002] Conventionally, a rotary damper including a vane protruding from a shaft, a flow path formed in the vane, and a valve for preventing backflow of oil in the flow path is known.

[0003] For example, Patent Document 1 below discloses a vane (first blade part 3c, second blade part 3d) protruding from a shaft (shaft 3), a flow path (first flow path 3c1, second flow path 3d1) formed in the vane, and a valve (vane 4) for preventing backflow of oil in the flow path. The shaft has a hole (mounting hole 3e) penetrating the shaft in the radial direction. The valve has a first part (an intermediate part between the back surface 4d1 and the back surface 4d2) located in the hole and a second part (first side surface 4a1, second side surface 4a2) for opening and closing the flow path (see FIGS. 5 to 10 of Patent Document 1).

[0004] However, in the rotary damper disclosed in Patent Document 1, the valve (vane 4) has ends (bending part ends 4b1, bending part ends 4b2) at the same height as the ends of the vanes (first blade part 3c, second blade part 3d), and the valve inserted into the hole (mounting hole 3e) is not held by the shaft (shaft 3) so as not to move in the radial direction. Therefore, when the shaft rotates, the valve contacts the peripheral wall of the housing (housing 2), and friction occurs between them (see FIG. 4 of Patent Document 1). Thus, the peripheral wall of the housing is worn due to this friction, and as a result, the torque decreases.

[0005] For example, Patent Document 2 below discloses a rotary damper comprising a vane (blade portion 4) protruding from a shaft (rotating axis 2), a flow path (flow passage 4a) formed in the vane, and a valve (valve body 6) for preventing backflow of oil in the flow path, wherein the shaft has a recess (strip-shaped recess 2c) on its outer circumference, and the valve has an engaging portion (curved portion 6a) that engages with the recess and a valve portion (valve portion 6b) that opens and closes the flow path (see Figure 2 of Patent Document 2).

[0006] However, in the rotary damper disclosed in Patent Document 2, the engaging portion (curved portion 6a) of the valve (valve body 6) is in contact with the partition wall (partition wall 5) of the housing (casing 1). As a result, friction occurs between the engaging portion of the valve and the partition wall of the housing when the shaft (rotating axis 2) rotates (see Figures 4 and 5 of Patent Document 2). Consequently, this friction causes wear on the partition wall of the housing, resulting in a decrease in torque. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-035882 [Patent Document 2] Japanese Patent Publication No. 2005-113980 [Overview of the project] [Problems that the invention aims to solve]

[0008] The problem that this invention aims to solve is to avoid contact between the valve and the housing. [Means for solving the problem]

[0009] To solve the above problems, the present invention provides a vane protruding from a shaft, a flow path formed in the vane, and a valve for preventing backflow of oil in the flow path, wherein the shaft has a hole having depth in the axial direction and a groove penetrating the circumferential wall of the hole, the flow path is formed at a position away from the outer edge of the vane, and the valve is inserted into the hole and engages with the circumferential wall of the hole. arc-shaped The engaging portion and the opening and closing of the flow path plate-shaped A valve portion and a portion located between the engaging portion and the valve portion, which is inserted into the groove. plate-shaped Having an intermediate part When the shaft is not rotating, the bent portion where the valve portion and the intermediate portion intersect contacts the base of the vane, causing the valve portion to be in close contact with the vane, and when the oil flows through the passage, the bent portion separates from the base of the vane. We provide rotary dampers. [Effects of the Invention]

[0010] According to the present invention, since the valve has an engaging portion that engages with the circumferential wall of a hole formed in the shaft, the valve is held by the shaft so as not to move radially. Also, since the flow path is formed away from the outer edge of the vane, the valve portion does not need to have an end at the same height as the end of the vane in order to close the flow path. Therefore, the rotary damper according to the present invention can avoid contact between the valve and the circumferential wall of the housing. Furthermore, according to the present invention, since the engaging portion of the valve is inserted into a hole formed in the shaft, the partition wall of the housing is in contact with the shaft. Therefore, the rotary damper according to the present invention can avoid contact between the valve and the partition wall of the housing. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a perspective view of a rotary damper according to an embodiment. [Figure 2] Figure 2 is a longitudinal cross-sectional view of a rotary damper according to an embodiment. [Figure 3] Figure 3 is a cross-sectional view of a rotary damper according to an embodiment. [Figure 4] Figure 4 is a bottom view of the rotor used in the embodiment. [Figure 5] Figure 5 is a perspective view of the valve used in the embodiment. [Figure 6]FIG. 6 is an enlarged view of part A in FIG. 3. [Figure 7] FIG. 7 is a diagram for explaining the operation of the rotary damper according to the embodiment.

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments.

Embodiment

[0013] Referring to FIG. 1, the rotary damper according to the embodiment includes a housing 10 and a rotor 20.

[0014] Referring to FIGS. 2 and 3, the housing 10 includes a cylindrical peripheral wall 11, a partition wall 12 protruding from the peripheral wall 11, a first end wall 13 closing one end of the peripheral wall 11, and a second end wall 14 closing the other end of the peripheral wall 11. The partition wall 12 is a partition that separates two oil chambers 30 formed in the housing 10.

[0015] The oil chamber 30 is a space into which oil is injected and is formed around a shaft 21 that constitutes the rotor 20. The oil chamber 30 is divided into two chambers, a first chamber 31 and a second chamber 32, by a vane 22 that constitutes the rotor 20.

[0016] The rotor 20 includes a shaft 21 and vanes 22 protruding from the shaft 21. The shaft 21 is connected to an object that transmits a rotational force to the rotor 20. However, depending on the usage mode, the housing 10 may rotate around the rotor 20. In this case, the shaft 21 is connected to an object that prevents the rotation of the rotor 20.

[0017] The vane 22 is installed in the oil chamber 30 and moves in the oil chamber 30 by the rotation of the shaft 21 to pressurize the oil. The vane 22 has a flow path 40 penetrating in the rotational direction of the vane 22. The flow path 40 consists of small holes and is formed at a position away from the outer edge of the vane 22. Here, the "outer edge of the vane 22" specifically means the first end face 22a of the vane 22 facing the first end wall 13, the second end face 22b of the vane 22 facing the second end wall 14, and the tip face 22c of the vane 22 facing the peripheral wall 11.

[0018] Referring to FIGS. 2 and 4, the shaft 21 has a hole 21a having a depth in the axial direction. The shaft 21 also has a groove 21b penetrating the peripheral wall of the hole 21a.

[0019] Referring to FIG. 3, the rotary damper according to the embodiment includes a valve 50.

[0020] Referring to FIG. 5, the valve 50 is formed by shaping a single leaf spring into a predetermined shape. This valve 50 includes a curved engaging portion 51, a plate-like valve portion 52, and an intermediate portion 53 located between the engaging portion 51 and the valve portion 52. A spring 54 for urging the valve portion 52 in a direction to contact the vane 22 is provided in the intermediate portion 53.

[0021] Referring to FIG. 6, the engaging portion 51 is inserted into the hole 21a and engages with the peripheral wall of the hole 21a. The radial movement of the valve 50 is prevented by the engagement between the engaging portion 51 and the peripheral wall of the hole 21a. The intermediate portion 53 is inserted into the groove 21b. The valve portion 52 is in close contact with the vane 22 to close the flow path 40. In the embodiment, since the flow path 40 is formed at a position away from the outer edge of the vane 22, the radial length of the valve portion 52 is shorter than the radial length of the vane 22. Also, the valve 50 is held by the shaft 21 so as not to move radially. Therefore, the valve 50 does not contact the peripheral wall 11 of the housing 10. The end of the spring 54 is in contact with the wall surface of the groove 21b, and the restoring force of the spring 54 acts on the valve portion 52.

[0022] The rotary damper according to this embodiment operates as follows: When the shaft 21 is not rotating, the valve portion 52 of the valve 50 is in close contact with the vane 22, closing the flow path 40, as shown in Figure 6.

[0023] When the shaft 21 rotates in one direction, the vanes 22 pressurize the oil in the first chamber 31. As shown in Figure 6, the valve portion 52 of the valve 50 is in close contact with the vanes 22, closing the passage 40. This prevents backflow of oil in the passage 40. At this time, the engaging portion 51 of the valve 50 is inserted into the hole 21a formed in the shaft 21, so the valve 50 does not come into contact with the partition wall 12 of the housing 10. The rotary damper generates torque because the oil does not flow through the passage 40.

[0024] When the shaft 21 rotates in the opposite direction, the vane 22 pressurizes the oil in the second chamber 32. As shown in Figure 7, the valve portion 52 of the valve 50 separates from the vane 22 due to the oil pressure. This opens the passage 40. At this time, deformation occurs in the spring 54 of the valve 50. As a result, the spring 54 stores elastic energy. Because the oil flows through the passage 40, the rotary damper generates less torque than when the shaft 21 rotates in one direction.

[0025] Subsequently, when the shaft 21 stops or rotates in one direction, the restoring force of the spring 54 causes the valve portion 52 to quickly come into close contact with the vane 22, closing the flow path 40. The rotary damper according to this embodiment can improve the response performance of the valve 50 by means of the spring 54. [Explanation of symbols]

[0026] 10 Housing 11 Peripheral wall 12 Bulkhead 13. First End Wall 14. Second End Wall 20 rotors 21 Shaft 21a hole 21b Groove 22 Bane 22a 1st end face 22b Second end surface 22c Tip surface 30 Oil room 31 Room 1 32 Room 2 40 flow channels 50 valves 51 Engaging part 52 Valve section 53 Middle section 54 springs

Claims

1. A rotary damper comprising a vane protruding from a shaft, a flow path formed in the vane, and a valve for preventing backflow of oil in the flow path, wherein the shaft has a hole having axial depth and a groove penetrating the circumferential wall of the hole, the flow path is formed at a position away from the outer edge of the vane, the valve is inserted into the hole and has an arc-shaped engaging portion that engages with the circumferential wall of the hole, a plate-shaped valve portion that opens and closes the flow path, and a plate-shaped intermediate portion located between the engaging portion and the valve portion and inserted into the groove, wherein when the shaft is not rotating, the bent portion where the valve portion and the intermediate portion intersect contacts the base of the vane, causing the valve portion to be in close contact with the vane, and when the oil flows through the flow path, the bent portion separates from the base of the vane.

2. The rotary damper according to claim 1, wherein a spring is provided in the intermediate portion that biases the bent portion in a direction that brings it into contact with the base of the vane.

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