JP2014178011A - Rotary damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary damper capable of rotating a rotor at a higher speed to open a communication passage, when the communication passage is opened by a valve element, thereby the rotor is rotated to open the same.SOLUTION: A first communication groove 7A is formed on an inner peripheral face of an accommodation hole of a casing 1. A second communication groove 7B is formed on an outer peripheral face of a piston 3. The first communication groove 7A and the second communication groove 7B are disposed on the same position in the circumferential direction of the accommodation hole so that the first communication groove 7A and the second communication groove 7B configure one communication hole 7 in the shape of one hole.

Description

  The present invention relates to a rotary damper that is provided between a housing and a rotating body and suppresses the rotational speed of the rotating body to a low speed.

  In general, as described in Patent Document 1 below, this type of rotary damper includes a casing having an accommodation hole whose one end is open and the other end is closed by a bottom, and an opening side of the accommodation hole. A rotor provided rotatably at the end, and a piston provided so as to be slidable and non-rotatable inside an accommodation hole between the rotor and the bottom. A male screw is formed on the rotor. On the other hand, a screw hole is formed in the piston. A male screw is screwed into the screw hole. Therefore, when the rotor rotates, the piston moves in the axial direction of the casing. For example, when the rotor rotates clockwise, the piston moves to the bottom side, and when the rotor rotates counterclockwise, the piston moves to the rotor side.

  By providing the piston inside the accommodation hole, the interior of the accommodation hole is divided into a first chamber on the rotor side and a second chamber on the bottom side. The first and second chambers are filled with a fluid such as a viscous fluid. The first and second chambers communicate with each other through a communication path.

  The piston is provided with a valve body. This valve body is for opening and closing the communication path, and closes the communication path when the piston moves to the bottom side, and opens the communication path when the piston moves to the rotor side. When the valve body closes the communication passage, the fluid in the second chamber flows into the first chamber through a resistance path such as an orifice. Due to the flow resistance at this time, the moving speed of the piston is suppressed to a low speed, and consequently the rotational speed of the rotor is suppressed to a low speed. When the valve element opens the communication path, the fluid in the first chamber flows into the second chamber through the communication path. The flow resistance in the communication path is small. Therefore, the piston can move at high speed, and the rotor can rotate at high speed.

China Utility Model Notification CN20128784Y

  In the rotary damper, it is desired that the rotor can rotate at a higher speed when the valve body opens the communication path. Such a request can be achieved by increasing the flow rate of the communication path. One method for increasing the flow rate is to increase the flow passage area (cross-sectional area) of the communication path. However, when the flow path area of the communication path is increased, the rotary damper is correspondingly enlarged. This invention makes it a subject to provide the rotation damper which can enlarge the flow volume of a communicating path, without enlarging a rotation damper.

The present invention has been made to solve the above-described problems. A casing having one end opened and the other end closed by a bottom, a rotor rotatably provided in the casing, and the rotor A piston that is slidably and non-rotatably provided inside the casing between the bottom and divides the inside of the casing between the bottom and the rotor into a first chamber and a second chamber. And a moving means for moving the piston following the rotation of the rotor, a communication path for communicating the first chamber and the second chamber, and a valve body for opening and closing the communication path, In the rotary damper in which the inside of the casing located between the bottom and the rotor is filled with fluid, a first communication groove is formed on the inner peripheral surface of the casing, and a second communication groove is formed on the outer peripheral surface of the piston. Communication groove is formed And the first communicating groove and the second communication groove is arranged to face each other in the radial direction of the casing, and wherein said communication passage is constituted by the first and second communicating groove.
In this case, the piston is slidable between the first position and the second position, and the first communication groove has the piston connected to the first position, the first position, and the second position. When the piston is located between the intermediate position and the second position, the valve body maintains the open state. The second communication groove is closed by the valve body when the piston moves from the first position to the second position, and the piston is moved from the second position to the first position. When moving up to, it is desirable to keep it open.
The piston is slidable between a first position and a second position, and the first communication groove and the second communication groove are configured such that the piston is moved from the first position to the second position. When moving toward the position, it is preferably closed by the valve body, and when the piston moves from the second position toward the first position, it is preferably maintained in the open state.

  According to the present invention having the above-described configuration, the first communication groove and the second communication groove are disposed to face each other, so that the first and second communication grooves form one communication path. Compared to the case where the first communication groove and the second communication groove are not opposed to each other and the communication paths are configured separately from each other, the cross-sectional areas of the first and second communication grooves When the (channel area) is constant, the circumference of the communication path of the present invention can be made shorter than the circumference of the communication path in the case of comparison. In other words, when the circumference of the communication path of the present invention is the same as the circumference of the communication path to be compared, the flow area of the communication path of the present invention is more than the flow area of the communication path of the comparison target. Can be bigger. Therefore, according to the present invention, the flow rate of the communication path can be increased. Therefore, the piston can be moved at a higher speed, and the rotor can be rotated at a higher speed accordingly. In addition, the first and second communication grooves are merely arranged opposite to each other, and their cross-sectional areas are not increased. Therefore, the rotary damper does not become large.

FIG. 1 is a view showing a first embodiment of the present invention in a state where the rotor is rotated to an initial position, FIG. 1 (A) is a front view thereof, and FIG. 1 (B) is a plan view thereof. It is. FIG. 2 is a view showing the same embodiment with the rotor rotated by approximately 70 ° from the initial position toward the limit position, and FIG. 2 (A) is a front view thereof, and FIG. 2 (B). Is a plan view thereof. FIG. 3 is a view showing the embodiment with the rotor rotated to a limit position, in which FIG. 3 (A) is a front view and FIG. 3 (B) is a plan view thereof. FIG. 4 is an enlarged cross-sectional view taken along line XX in FIG. FIG. 5 is an enlarged cross-sectional view taken along line XX in FIG. FIG. 6 is an enlarged cross-sectional view taken along line XX in FIG. FIG. 7 is a cross-sectional view similar to FIG. 6 showing a state immediately after the rotor is rotated from the limit position to the initial position side. 8 is a cross-sectional view similar to FIG. 5 showing a state when the rotor is rotated from the limit position toward the initial position to the same position as that shown in FIG. FIG. 9 is a cross-sectional view similar to FIG. 4 showing a state when the rotor is rotated from the limit position to the initial position. 10 is a cross-sectional view taken along the line XX of FIG. 11 is a YY cross-sectional view of FIG. FIG. 12 is an exploded perspective view showing the embodiment. FIG. 13 is an exploded perspective view of the same embodiment as viewed from a direction different from FIG. FIG. 14 is a front view showing a second embodiment of the present invention with the rotor positioned at the initial position. FIG. 15 is a cross-sectional view similar to FIG. 4 of the same embodiment. FIG. 16 is a cross-sectional view similar to FIG. 5 of the same embodiment. FIG. 17 is a cross-sectional view similar to FIG. 6 of the same embodiment. 18 is an enlarged cross-sectional view taken along line XX in FIG.

The best mode for carrying out the present invention will be described below with reference to the drawings.
1 to 13 show a first embodiment of the present invention. The rotary damper A of this embodiment mainly includes a casing 1, a rotor 2, a piston 3, and a valve body 4 as shown in FIGS. 1 to 9, the damper A is disposed with its axis line (this axis line being the axis line of the casing 1 and the rotation center line of the rotor 2) facing up and down. Therefore, each configuration of the rotary damper A will be described using the upper and lower sides. The rotary damper A may be arranged in the horizontal direction or in another direction.

  The casing 1 is made of a metal cylinder having a circular cross section, and the inside thereof is an accommodation hole 11. The accommodation hole 11 has an opening 1d at its upper end, and the lower end is closed by the bottom 1a.

  A pair of wide flat portions 1 b and 1 b and a pair of narrow flat portions 1 c and 1 c are formed on the peripheral wall portion of the casing 1. Both flat portions 1 b and 1 c extend from a position away from the upper end of the casing 1 by a predetermined distance to the lower end of the casing 1. A portion of the accommodation hole 11 where the flat portions 1 b and 1 c are formed is a sliding hole portion 12.

The pair of wide flat portions 1 b and 1 b extend in parallel with the axis of the casing 1 and are disposed 180 degrees apart in the circumferential direction of the casing 1. That is, the pair of wide flat portions 1b and 1b are arranged so as to face each other with the axis of the casing 1 interposed therebetween. By forming the wide flat portions 1 b and 1 b, first sliding surfaces 13 and 13 extending in parallel with the axis of the casing 1 are formed on the inner peripheral surface of the sliding hole portion 12.

The pair of narrow flat portions 1 c and 1 c extend in parallel with the axis of the casing 1 and are disposed 180 degrees apart in the circumferential direction of the casing 1. In addition, the pair of narrow flat portions 1c and 1c are disposed 90 ° away from the pair of wide flat portions 1b and 1b in the circumferential direction of the casing 1. As a result, the wide flat portions 1b and the narrow flat portions 1c are alternately arranged in the circumferential direction of the casing 1 every 90 °. The narrow flat portion 1c is narrower than the wide flat portion 1b. By forming the narrow flat portions 1 c and 1 c, second sliding surfaces 14 and 14 extending in parallel with the axis of the casing 1 are formed on the inner peripheral surface of the sliding hole portion 12.

By forming the first sliding surfaces 13 and 13 and the second sliding surfaces 14 and 14 on the inner peripheral surface of the sliding hole portion 12, the sectional shape of the sliding hole portion 12 is changed to the first sliding surface 13. The longitudinal direction is defined as a long direction, and the direction along the second sliding surface 14 is defined as a short direction. In addition, the four corners of the sliding hole 12 are formed by arcuate surfaces with the axis of the casing 1 as the center of curvature.

  The pair of wide flat portions 1b, 1b and the pair of narrow flat portions 1c, 1c can be formed as follows, for example. That is, a metal core (not shown) having the same cross-sectional shape as the sliding hole 12 is inserted into the accommodation hole 11. Then, the surrounding wall part of the casing 1 is pressed and pressed on the flat surface corresponding to the 1st sliding surfaces 13 and 13 of a metal core. Thereby, the wide flat portions 1b and 1b are formed. Next, the peripheral wall portion of the casing 1 is pressed and pressed against the flat surface corresponding to the second sliding surfaces 14 and 14 of the core metal. Thereby, a narrow flat portion 1c is formed. The order of forming the wide flat portion 1b and the narrow flat portion 1c may be reversed from the above, or both may be formed simultaneously.

  The rotor 2 has a fitting shaft portion 21 having a circular cross section. The fitting shaft portion 21 has the same outer diameter as the inner diameter of the accommodation hole 11, and rotates around the axis of the accommodation hole 11 (the axis of the casing 1) at the end of the accommodation hole 11 on the opening 1 d side. It can be fitted. Thereby, the rotor 2 is rotatably supported by the casing 1. A space between the outer peripheral surface of the fitting shaft portion 21 and the inner peripheral surface of the accommodation hole 11 is sealed by a seal member 51 such as an O-ring. Note that after the fitting shaft portion 21 is fitted into the receiving hole 11, the upper end portion of the peripheral wall portion of the casing 1 is folded back radially inward, so that the fitting shaft portion 21 is attached to the casing 1 in the stop ring 52. It is prevented from coming off through

  A connecting shaft portion 22 is formed integrally with the fitting shaft portion 21 on the upper end surface of the fitting shaft portion 21. The connecting shaft portion 22 protrudes upward from the casing 1. The connecting shaft portion 2 is formed in a non-circular shape, and rotates in either one of a housing (not shown) such as a building pillar or a toilet body, and a rotating body (not shown) such as a door or a toilet lid. Linked impossible. The casing 1 is non-rotatably connected to the other of the casing and the rotating body. In this embodiment, the casing 1 is connected to the toilet body, and the connecting shaft portion 22 is connected to the toilet lid. Therefore, when the toilet lid rotates, the rotor 2 rotates relative to the casing 1.

  The rotor 2 is located at the initial position shown in FIG. 1 when the toilet lid is located at the closed position, and is located at the maximum rotation position shown in FIG. 3 when the toilet lid is located at the open position. However, the maximum rotation angle of the rotor 2 is set to be slightly larger than the angle between the initial position and the maximum rotation position, and the rotor 2 is directed from the initial position toward the maximum rotation position (the toilet lid is closed). It is a direction from the position to the open position, and in FIG. 1 (B) to FIG. 3 (B), the counterclockwise direction; hereinafter referred to as the open direction) exceeds the maximum rotation position by a slight angle (for example, about 5 °). Direction from the maximum rotational position to the initial position side (the direction in which the toilet lid is directed from the open position to the closed position, clockwise in FIGS. 1B to 3B); Can be rotated by a slight angle (for example, about 5 °) beyond the initial position.

  A male thread portion 23 is formed integrally with the fitting shaft portion 21 on the lower end surface of the fitting shaft portion 21. The male screw portion 23 is arranged with its axis line coincident with the axis line of the fitting shaft portion 21. The male screw portion 23 has a plurality of threads. The plurality of screws are formed to increase the lead angle of the screw. If there is no need to increase the lead angle, a single thread may be formed.

  A small-diameter shaft portion 24 is formed integrally with the male screw portion 23 on the lower end surface of the male screw portion 23. The small-diameter shaft portion 24 is disposed with its axis line aligned with the axis line of the male screw portion 23. The outer diameter of the small-diameter shaft portion 24 is smaller than the diameter of the valley of the male screw portion 23. The outer diameter of the small diameter shaft portion 24 may be the same as the diameter of the thread valley of the male screw portion 23.

  The piston 3 is accommodated in the portion between the fitting shaft portion 21 and the bottom portion 1 a of the rotor 2 in the accommodation hole 11, that is, the sliding hole portion 12. Thereby, the inside of the accommodation hole 11 is divided into a first chamber 6A between the fitting shaft portion 21 and the piston 3 and a second chamber 6B between the piston 3 and the bottom portion 1a. A fluid such as a viscous fluid is accommodated in the internal space of the accommodation hole 11 between the fitting shaft portion 21 and the bottom portion 1a, including the first and second chambers 6A and 6B.

  The piston 3 is formed so that the cross-sectional shape of the outer peripheral surface thereof is the same cross-sectional shape as the inner peripheral surface of the sliding hole portion 12, and the sliding hole portion 12 extends in the vertical direction (the axial direction of the casing 1). It is slidably and non-rotatably accommodated. Accordingly, the first flat surface portions 31, 31 corresponding to the pair of first sliding surfaces 13, 13 are formed on the outer peripheral surface of the piston 3, and the first planar portions 31, 31 corresponding to the pair of second sliding surfaces 14, 14 are formed. Two plane portions 32, 32 are formed. The first and second sliding surfaces 13 and 14 extend from the upper end surface of the piston 3 to the lower end surface. The first and second flat portions 31 and 32 are in surface contact with the first and second sliding surfaces 13 and 14, respectively, so that the rotation of the piston 3 with respect to the casing 1 is prevented.

  The piston 3 is formed with a female thread portion 33 extending on the axis from the upper end surface to the lower end surface. The male screw portion 23 of the rotor 2 is screwed into the female screw portion 33. Therefore, when the rotor 2 rotates, the piston 3 moves in the vertical direction. In this case, the piston 3 moves upward when the rotor 2 rotates in the opening direction, and moves downward when the rotor 2 rotates in the closing direction. As is clear from this, in the rotary damper A, the male screw portion 23 and the female screw portion 33 constitute moving means for moving the piston 3 following the rotation of the rotor 2.

  The piston 3 is located at the upper limit position (first position) shown in FIGS. 6 and 7 when the rotor 2 rotates to the maximum rotation position, and when the rotor 2 rotates to the initial position, the lower limit shown in FIGS. It is located at the position (second position). However, the piston 3 can move upward by a slight distance beyond the upper limit position, corresponding to the fact that the rotor 2 can be rotated by an angle slightly larger than the angle between the initial position and the maximum rotational position. It is possible to move downward by a small distance beyond the lower limit position.

  A support cylinder portion 34 is formed on the lower end surface of the piston 3. The inner diameter of the support cylinder portion 34 is set to be the same as the outer diameter of the small diameter shaft portion 24 of the rotor 2. The small diameter shaft portion 24 is inserted into the support cylinder portion 34 so as to be rotatable and slidable. A space between the inner peripheral surface of the support cylinder portion 34 and the outer peripheral surface of the small diameter shaft portion 24 is sealed by a seal member 53 such as an O-ring.

  As shown in FIGS. 4 to 9, when the piston 3 moves upward, the internal volume of the first chamber 6A decreases and the internal volume of the second chamber 6B increases. As a result, the fluid in the first chamber 6A tends to flow into the second chamber 6B. Conversely, when the piston 3 moves downward, the internal volume of the first chamber 6A increases and the internal volume of the second chamber 6B decreases. As a result, the fluid in the second chamber 6B tends to flow into the first chamber 6A.

In order to allow fluid to flow between the first chamber 6A and the second chamber 6B, a communication path for communicating them between the first chamber 6A and the second chamber 6B. 7 is provided. The communication path 7 is configured by a first communication groove 7 </ b> A formed on the inner peripheral surface of the sliding hole portion 12 of the casing 1 and a communication groove 7 </ b> B formed on the outer peripheral surface of the piston 3.

  7 A of 1st communicating grooves are formed in the 2nd sliding face 14 by making the center part of the width direction (circumferential direction of the casing 1) of the narrow flat part 1c protrude toward the radial direction outer side of the casing 1. Yes. The protruding amount of the narrow flat portion 1c for forming the first communication groove 7A is such that the outermost portion of the outer surface of the protruding portion is in contact with the arc surface constituting the outer peripheral surface of the casing 1. The size is set.

The first communication groove 7 </ b> A has a width narrower than the width of the second sliding surface 14, and is disposed at the center in the width direction of the second sliding surface 14. As shown in FIGS. 4 to 9, the upper end portion of the first communication groove 7 </ b> A is disposed at substantially the same position as the upper end portion of the second sliding surface 14, and is always in communication with the first chamber 6 </ b> A. . On the other hand, as shown in FIGS. 4 and 9, the lower end portion of the first communication groove 7 </ b> A is disposed so as to be located a predetermined distance above the lower end surface of the piston 3 located at the lower limit position. As will be described later, the lower end portion of the first communication groove 7A is switched between the communication state and the cutoff state with respect to the second chamber 6B by the piston 3 and the valve body 4.

  Since the width of the first communication groove 7A is narrower than the width of the second sliding surface 14, both side portions in the width direction of the second sliding surface 14 remain as flat surfaces. Then, both side portions of the second flat surface portion 32 of the piston 3 are slidably in surface contact with both side portions of the second sliding surface 14. As is clear from this, both side portions of the second sliding surface 14 in the width direction are inward plane portions, and both side portions of the second plane portion 32 are outward plane portions.

  The second communication groove 7 </ b> B is formed in each second flat portion 32 of the piston 3. Here, the 2nd plane part 32 is arrange | positioned at the both ends of the longitudinal direction in the cross-sectional shape of piston 3 which makes cross-sectional rectangular shape. Therefore, the second communication grooves 7 </ b> B and 7 </ b> B are also arranged at both ends in the longitudinal direction in the cross-sectional shape of the outer peripheral surface of the piston 3. The length of the second communication groove 7B is the same as the length of the piston 3, and extends from the upper end to the lower end of the second flat portion 32. The upper end of the second communication groove 7B is always in communication with the first chamber 6A. As will be described later, the lower end of the second communication groove 7B is switched between the communication state and the cutoff state by the valve body 4 with respect to the second chamber 6B.

The second communication groove 7 </ b> B is disposed in the center portion in the width direction of the second plane portion 32. Accordingly, the second communication groove 7B faces the first communication groove 7A and communicates with each other as shown in FIG. As a result, one hole is formed by the first communication groove 7 </ b> A and the second communication groove 7 </ b> B, and the hole serves as the communication path 7. Although the width of the second communication groove 7B is narrower than the width of the second flat portion 32, the width of the second communication groove 7B may be the same as the width of the first communication groove 7A. It may be narrower than the width of the communication groove 7A.

  The valve body 4 is provided on the support cylinder portion 34 of the piston 3 so as to be movable between an open position and a closed position in the axial direction of the piston 3 (the axial direction of the casing 1). That is, a locking projection 35 is formed at the lower end of the support cylinder 34. The locking projection 35 has an oval cross section and is arranged with its longitudinal direction oriented in a direction perpendicular to the longitudinal direction of the sliding hole portion 12.

  The valve body 4 is formed in a ring shape. The cross-sectional shape inside the valve body 4 is the same as the cross-sectional shape of the locking projection 35. Therefore, the locking projection 35 can be inserted into the valve body 4, and when the locking projection 35 passes through the valve body 4, the locking projection 35 of the support cylinder portion 34 is formed inside the valve body 4. The upper part is inserted. When the valve body 4 is rotated by 90 ° with respect to the locking protrusion 35 in this state, the short side direction of the valve body 4 is opposed to the longitudinal direction of the locking protrusion 35. As a result, when the valve body 4 tries to come out from the support cylinder portion 34, both ends in the short direction of the valve body 4 abut against both ends in the longitudinal direction of the locking projection 35. As a result, the valve body 4 is prevented from coming out of the support cylinder portion 34 downward.

  The valve body 4 has an external cross-sectional shape that is the same as the cross-sectional shape of the sliding hole portion 12. Therefore, the valve body 4 can be inserted into and removed from the sliding hole portion 12, and is inserted into the sliding hole portion 12 while being rotated by 90 ° after being inserted through the locking projection 35. As a result, the valve body 4 is fitted in the sliding hole portion 12 of the casing 1 so as not to rotate but to be slidable.

  The thickness of the valve body 4 (the dimension of the casing 1 in the axial direction) is thinner than the distance between the lower end surface of the piston 3 and the upper surface of the locking projection 35. Therefore, the valve body 4 is movable in the vertical direction by the difference between the distance between the lower end surface of the piston 3 and the upper surface of the locking projection 35 and the thickness of the valve body 4. When the valve body 4 hits the lower end surface of the piston 3, it cannot move further upward. The position of the piston 3 at this time is a closed position. When the valve body 4 hits the locking projection 35, it cannot move any further downward. The position of the valve body 4 at this time is an open position.

  The communication state and the blocking state by the first communication groove 7A and the second communication groove 7B between the first chamber 6A and the second chamber 6B are as follows according to the position of the piston 3 and the position of the valve body 4. To change.

  First, the case where the valve body 4 is located in the open position will be described. As shown in FIGS. 4 to 6, when the valve body 4 is located in the open position, the upper surface of the valve body 4 and the piston An annular gap S <b> 1 is formed between the lower end surface 3 and the lower end surface 3. As a result, the lower end portion of the second communication groove 7 </ b> B is formed between the gap S <b> 1 and a portion located in the longitudinal direction in the cross section of the inner peripheral surface of the valve body 4 and the outer peripheral surface of the support cylinder portion 34. It communicates with the second chamber 6B via the gap S2. Therefore, when the valve body 4 is located at the open position, the first chamber 6A and the second chamber 6B communicate with each other via the second communication groove 7B regardless of the position of the piston 3. .

  The communication state between the first communication groove 7A and the second chamber 6A will be described. When the valve body 4 is located at the open position, the piston 3 has the upper limit position shown in FIG. When the lower surface is located between the lower end edge of the first communication groove 7A and the intermediate position shown in FIG. 8 located at the same position, the lower end portion of the first communication groove 7A directly communicates with the second chamber 6B. ing. Therefore, the first chamber 6A and the second chamber 6B communicate with each other through the first communication groove 7A. Therefore, when the valve body 4 is located at the open position, when the piston 3 is located between the upper limit position and the intermediate position, the first chamber 6A and the second chamber 6B are in communication with each other. The groove 7A and the second communication groove 7B communicate with each other, that is, through the communication path 7 as a whole.

  When the piston 3 is positioned between the intermediate position and the blocking position where the lower end surface of the piston 3 is located at the same position as the lower end edge of the first communication groove 7A, the lower end portion of the first communication groove 7A is The second communication groove 7B communicates with the second chamber 6B via the lower end portion and the gaps S1 and S2. Therefore, also in this case, the first chamber 6A and the second chamber 6B communicate with each other through both the first communication groove 7A and the second communication groove 7B.

  When the piston 3 is positioned between the cutoff position and the lower limit position, the lower end portion of the first communication groove 7A is closed by the piston 3. For this reason, the fluid flowing between the first chamber 6A and the second chamber 6B once flows only in the lower end portion of the second communication groove 7B. Therefore, when the valve body 4 is located at the open position, when the piston 3 is located between the cutoff position and the lower limit position, the first chamber 6A and the second chamber 6B are substantially Is communicated only through the second communication groove 7B.

  Next, the case where the valve body 4 is located at the closed position will be described. When the valve body 4 is located at the closed position, the gap S1 is closed. As a result, the valve body 4 closes the space between the lower end of the second communication groove 7B and the second chamber 6B. Therefore, when the valve body 4 is located at the closed position, the second communication groove 7B does not participate in the communication between the first chamber 6A and the second chamber 6B.

  The first communication groove 7A is formed so that the piston 3 is at the upper limit position shown in FIG. 7 and the intermediate position shown in FIG. On the other hand, the lower end of the first communication groove 7A is positioned at a predetermined distance, that is, a lower position by a distance between the closed position and the open position of the valve body 4). The part communicates directly with the second chamber 6B. Accordingly, when the valve body 4 is located at the closed position, the first chamber 6A and the second chamber 6B are connected to the first communication groove when the piston 7 is located between the upper limit position and the intermediate position. It communicates only through 7A.

  When the piston 3 moves downward from the intermediate position, the lower end portion of the first communication groove 7A is closed by the valve body 4. Therefore, when the valve body 4 is located at the closed position, when the piston 3 is located between the intermediate position and the lower limit position, the entire communication path 7 is blocked by the valve body 4. The fluid in the first and second chambers 6A and 6B does not flow through the communication path 7, that is, the first communication groove 7A and the second communication groove 7B. The fluid in the first and second chambers 6 </ b> A and 6 </ b> B flows through a slight gap necessary for sliding between the inner peripheral surface of the sliding hole portion 12 and the outer peripheral surface of the valve body 4. At this time, the slight gap functions as an orifice, and a large flow resistance is generated when the fluid flows through the gap. Due to this flow resistance, the moving speed of the piston 3 downward is suppressed to a low speed, and consequently the rotating speed of the rotor 2 in the closing direction is suppressed to a low speed.

  In the rotary damper A having the above configuration, it is assumed that the toilet lid of the toilet bowl provided with the rotary damper A is located at the closed position. At this time, the rotor 2 is located at the initial position, the piston 3 is located at the lower limit position shown in FIG. 4, and the valve body 4 is located at the open position. When the toilet lid and the rotor 2 are rotated in the opening direction, the piston 3 moves upward from the lower limit position. Then, the fluid in the first chamber 6A tries to flow into the second chamber 6B through the communication path 7. The valve body 4 is pushed downward by this fluid. As a result, the valve body 4 is maintained in the open position.

When the rotor 2 rotates in the opening direction from the initial position and the piston 3 moves from the lower limit position to the shut-off position along with the rotation, the first chamber 6A and the second chamber 6B are substantially separated as described above. The communication path 7 communicates only through the second communication groove 7B. Therefore, although the piston 3 moves upward at a high speed, the piston 3 moves at a slightly lower speed than the case where the first chamber 6A and the second chamber 6B communicate with each other through the entire communication path 7. Therefore, although the rotor 2 also rotates at a high speed, the rotation speed is suppressed to a slightly low speed.

  When the piston 3 reaches between the shut-off position and the intermediate position as the rotor 2 rotates in the opening direction, the lower end portion of the first communication groove 7A becomes the second via the second communication groove 7B and the gaps S1 and S2. It communicates with the room 6B. Accordingly, the first chamber 6A and the second chamber 6B communicate with each other through the first communication groove 7A and the second communication groove 7B. Therefore, the rotor 2 rotates at a high speed. However, since the lower end of the first communication groove 7A communicates with the second chamber 6B via the second communication groove 7B, the lower end of the first communication groove 7A communicates directly with the second chamber 6B. Rather than the resistance to the fluid. Therefore, the rotational speed of the rotor 2 can be suppressed slightly lower than when the piston 3 moves from the intermediate position to the upper limit position.

When the piston 3 crosses the intermediate position upward, the first communication groove 7A communicates directly with the second chamber 6B. As a result, the first chamber 6A and the second chamber 6B communicate with each other via both the second communication groove 7B and the first communication groove 7A. This is similar to the case where the piston 3 is located between the blocking position and the intermediate position, but the lower end portion of the first communication groove 7A communicates directly with the second chamber 6B than in this case. The flow resistance to the fluid is small by the amount. Accordingly, the piston 3 can move upward at a higher speed, and the rotor 2 can rotate in the opening direction at a higher speed.

Further, when the first chamber 6A and the second chamber 6B flow through both the first communication groove 7A and the second communication groove 7B, the two communication grooves 7A and 7B face each other to form one communication channel. Since the passage 7 is constituted, the inner periphery of the flow passage 7 is compared with the case where the first communication groove 7A and the second communication groove 7B are not opposed to each other and each of the communication passages is constituted independently. The circumference of the surface can be shortened. In other words, the peripheral length of one communication path 7 constituted by the first and second communication grooves 7A, 7B and the total circumference of the two communication paths respectively constituted by the first and second communication grooves. In the case where they are the same, the flow area (cross-sectional area) of one communication path 7 can be made larger than the total flow area of the two communication paths. Distribution resistance can be reduced. Therefore, the piston 3 can move at a higher speed, and the rotor 2 can rotate at a higher speed. When the toilet lid and the rotor 2 reach the open position, they stop. The state at this time is shown in FIG.

  When the toilet lid and rotor 2 rotate closed from the open position, the piston 3 moves downward, and the fluid in the second chamber 6B attempts to flow into the first chamber 6A through the communication path 7. Then, the valve body 4 is pushed up to the closed position by the fluid. As a result, the second communication groove 7B is closed. On the other hand, as described above, the inward communication path 7A maintains a state of communicating with the second chamber 6B until the piston 3 reaches the intermediate position from the open position. Accordingly, the first chamber 6A and the second chamber 6B are substantially communicated only via the first communication groove 7A, and the fluid in the second chamber 6B passes through the first communication groove 7A and the first It flows into the chamber 6A. Here, although the flow resistance of the first communication groove 7A is relatively small, the cross-sectional area of the first communication groove 7A, that is, the flow path area, is smaller than the flow path area of the second communication groove 7B. Accordingly, the flow resistance of the first communication groove 7A is larger than the flow resistance of the second communication groove 7B. For this reason, the piston 3 can move downward at a relatively high speed, but is suppressed to a lower speed than the case of moving upward. Therefore, the rotor 2 also rotates at a lower speed than during the opening rotation.

  When the piston 3 exceeds the intermediate position as the rotor 2 is closed, the valve body 4 blocks the lower end portion of the first communication groove 7A and the second chamber 6B. As a result, the first chamber 6A and the second chamber 6B are blocked from each other. For this reason, the fluid in the second chamber 6B passes through a slight gap necessary for sliding between the inner peripheral surface of the sliding hole portion 12 and the outer peripheral surface of the valve body 4 to the first chamber 6A side. To flow. The fluid that has passed between the inner peripheral surface of the sliding hole 12 and the outer peripheral surface of the valve body 4 is a gap (including the communication path 7) between the inner peripheral surface of the sliding hole 12 and the outer peripheral surface of the piston. ) And flows into the first chamber 6A. Here, when the fluid flows through the gap between the inner peripheral surface of the sliding hole portion 12 and the outer peripheral surface of the valve body 4, the gap acts as an orifice and generates a large flow resistance. Due to this flow resistance, the moving speed of the piston 3 downward is suppressed to a low speed, and consequently the rotating speed of the rotor 2 in the closing direction is suppressed to a low speed. When the rotor 2 reaches the closed position and stops, the piston 4 stops at the lower limit position. Thereafter, the valve body 4 moves downward to its open position by its own weight, and the rotary damper A is in the state shown in FIG.

  In the rotary damper A configured as described above, one communication path 7 is constituted by the first communication groove 7A and the second communication groove 7B. Comparing this communication path 7 with the case where the first communication groove 7A and the second communication groove 7B constitute two independent communication paths, respectively, the former communication path 7 and the latter two communication paths If the circulation area is the same, the circumferential length of the inner peripheral surface of the former communication path 7, that is, the length in the circumferential direction is made shorter than the total circumferential length of the latter two independent communication paths. be able to. In other words, if the circumference of the former communication path is the same as the total circumference of the latter two communication paths, the flow area of the former communication path is the sum of the latter two communication paths. The flow path area can be made larger. Therefore, according to this rotary damper A, the flow resistance of the communication path 7 can be reduced, and the flow rate of the communication path 7 can be increased accordingly. Therefore, the rotor 2 can be opened and rotated at a higher speed. In addition, the first and second communication grooves 7A and 7B do not need to have a large flow area. Therefore, the rotary damper A does not become large.

  Further, when the rotor 2 rotates in the closing direction from the maximum rotation position, when the piston 3 is located between the upper limit position and the lower limit position, the second communication groove 7B is closed by the valve body 4, Since the one communication groove 7A communicates the first chamber 6A and the second chamber 6B, the piston 3 can rotate downward at a relatively high speed, and the rotor 2 can be closed and rotated at a relatively high speed. Can do. Thereby, the time required for the rotor 2 to rotate from the maximum rotation position to the initial position, that is, the time required for the toilet lid to rotate from the open position to the closed position can be shortened.

Next, a second embodiment of the present invention shown in FIGS. 14 to 18 will be described. In the second embodiment, only the configuration different from that of the first embodiment will be described, and the same components as those of the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted. To do.

In the rotary damper B of the second embodiment, the narrow flat portion 1 c extends to the lower end of the casing 1. Correspondingly, the second sliding surface 14 and the first communication groove 7 </ b> A extend to the lower end of the casing 1.

A closing projection 41 is formed on each portion of the outer peripheral surface of the valve body 4 facing the narrow flat portions 1c, 1c. The closing protrusion 41 has the same shape as the first communication groove 7A and is slidably fitted into the first communication groove 7A with almost no clearance except for an inevitable clearance for sliding. Thereby, the intermediate part of the longitudinal direction of 7 A of 1st communicating grooves is closed. Accordingly, the first chamber 6A and the second chamber 6B do not communicate with each other only through the first communication groove 7A.

In the rotary damper B configured as described above, when the valve body 4 is located at the open position, the first communication groove 7A and the second communication groove 7B communicate with the second chamber 6B via the gaps S1 and S2. As a result, the first and second chambers 6A and 6B communicate with each other through the communication path 7.
Therefore, when the rotor 2 rotates open, the rotor 2 rotates at a high speed. On the contrary, when the valve body 4 is located at the closed position, the first communication groove 7A and the second communication groove 7B are closed, and the first and second chambers 6A and 6B are blocked. Therefore, when the rotor 2 rotates in a closed manner, the rotor 2 rotates at a low speed.

In addition, this invention is not limited to said embodiment, A various modification is employable in the range which does not deviate from the summary.
For example, in the above embodiment, the moving means is constituted by the male screw portion 23 and the female screw portion 33, but other known moving means may be adopted. For example, a cam mechanism is provided between the rotor 2 and the piston 3, and a compression coil spring is provided between the piston 3 and the bottom 1 a, and the piston 3 follows the rotation of the rotor 2 by the cam mechanism and the compression coil spring. And may be moved.
In the above embodiment, the small-diameter shaft portion 24 is formed on the lower end surface of the rotor 2, and the small-diameter shaft portion 24 is slidably and rotatably fitted on the inner peripheral surface of the piston 3. However, the small diameter shaft portion 24 is not necessarily formed.

A rotating damper B rotating damper 1 casing 1a bottom 1d opening 2 rotor 3 piston 4 valve body 6A first chamber 6B second chamber 7 communication path 7A first communicating groove 7B second communicating groove 12 sliding hole 23 male screw (Moving means)
33 Female thread (moving means)

Claims (3)

A casing having one end opened and the other end closed by a bottom, a rotor rotatably provided in the casing, and a slidable and rotating inside the casing between the rotor and the bottom A piston which is provided in an impossible manner and divides the inside of the casing between the bottom and the rotor into a first chamber and a second chamber, and a moving means for moving the piston following the rotation of the rotor And a communication passage that allows the first chamber and the second chamber to communicate with each other, and a valve body that opens and closes the communication passage, and a fluid is provided inside the casing that is located between the bottom and the rotor. In the rotary damper filled with
A first communication groove is formed on the inner peripheral surface of the casing, a second communication groove is formed on the outer peripheral surface of the piston, and the first communication groove and the second communication groove are arranged in the radial direction of the casing. A rotary damper, wherein the rotary damper is disposed to face each other, and the communication path is constituted by the first and second communication grooves. The piston is slidable between a first position and a second position, and the first communication groove is configured so that the piston has the first position, the first position, and the second position. When the piston is located between the intermediate position and the second position, the valve body is closed when the piston is located between the intermediate position and the second position. The second communication groove is closed by the valve body when the piston moves from the first position to the second position, and the piston moves from the second position to the first position. 2. The rotary damper according to claim 1, wherein the rotary damper is maintained in an open state. The piston is slidable between a first position and a second position, and the first communication groove and the second communication groove are arranged so that the piston moves from the first position to the second position. 2. The valve body according to claim 1, wherein the valve body is closed when moving toward the first position, and is kept open when the piston moves from the second position toward the first position. Rotating damper.

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