Door closer

Abstract

To provide a door closer capable of easily securing necessary closing force.SOLUTION: The door closer includes: a first spring 17 that deforms elastically when the door opens and restores to generate a closing force when the door closes; a second spring 18 that is placed separately from the first spring 17, and deforms elastically when the door opens and restores to generate a closing force when the door closes; and a third spring 19 that is placed separate from the first spring 17 and the second spring 18 and deforms elastically when the door opens, and restores when the door closes to generate a closing force. When the door opens, cams 13a and 13b elastically deform the first spring 17, and a piston 12 elastically deforms the second spring 18 and the third spring 19.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a door closer equipped with a cam and a piston. [Background technology]

[0002] The applicant has proposed a door closer equipped with a cam and a piston, as described in Patent Documents 1 and 2 below. By providing a cam, this door closer can obtain a large closing force just before fully closing. In addition, the rack and pinion mechanism allows the piston to move a large distance. This allows the flow rate of hydraulic oil passing through the flow control flow path to be increased, making it easy to adjust the flow rate of hydraulic oil. Meanwhile, further miniaturization of door closers is required, but miniaturizing door closers tends to result in insufficient closing force. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-193485 [Patent Document 2] Patent Publication No. 2021-95764 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a door closer that can easily ensure the required closing force. [Means for solving the problem]

[0005] The door closer of the present invention comprises a main shaft that rotates around an axis in a predetermined direction as the door is opened or closed, a cam that is attached to the main shaft and rotates together with the main shaft, a piston that moves in a direction perpendicular to the predetermined direction by a rack and pinion mechanism as the main shaft rotates, a first spring that elastically deforms when the door opens and restores its original shape when the door closes, generating a closing force, a second spring that is attached separately from the first spring and elastically deforms when the door opens and restores its original shape when the door closes, generating a closing force, and a third spring that is attached separately from the first and second springs and elastically deforms when the door opens and restores its original shape when the door closes, generating a closing force; when the door opens, the cam elastically deforms the first spring, and the piston elastically deforms the second and third springs.

[0006] With this configuration, when the door is closed, the closing force of the first spring acts on the cam. Therefore, a large closing force can be applied from the cam to the main shaft, especially when closing, allowing the door to close securely. Furthermore, during the door closing operation, the restoring force of the third spring acts on the piston in addition to the restoring force of the second spring, making it less likely that the closing force will be insufficient, allowing the door to close stably.

[0007] In particular, it is preferable to have a cam follower disposed between the cam and the first spring, which moves in a direction perpendicular to the predetermined direction as the cam rotates, and a third spring disposed between the piston and the cam follower. This configuration makes it easy to dispose the third spring. By utilizing the difference in the amount of movement between the piston and the cam follower, the third spring can be effectively elastically deformed when the door is opened, and the closing force of the third spring can be effectively applied to the piston when the door is closed.

[0008] Furthermore, it is preferable that the piston does not elastically deform the third spring from the closed state until the door is opened to a predetermined opening angle, and elastically deforms the third spring once the opening angle exceeds the predetermined opening angle. This configuration shortens the section in which the third spring elastically deforms. This simplifies the design of the third spring and improves its durability. Furthermore, the closing force of the third spring can be effectively applied to the door at a relatively large opening angle.

[0009] In addition, in the closed door state, the distance between the piston and the cam follower is preferably greater than the free length of the third spring. With this configuration, in the closed door state, a gap is created between the piston and the third spring or between the third spring and the cam follower. This makes it easy to shorten the section in which the third spring elastically deforms, and also simplifies the arrangement of the piston, cam follower, etc. [Effects of the Invention]

[0010] As described above, with three springs, the cam elastically deforms the first spring, and the piston elastically deforms the second and third springs, so even if the door closer is made smaller, there is less chance of a lack of closing force, and the required closing force can be easily secured. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a vertical cross-sectional view showing a door closer in an embodiment of the present invention, showing a door closed state. FIG. [Figure 2] Cross section AA of Figure 1. [Figure 3] Cross section B-B of Figure 1. [Figure 4] FIG. 4 is a vertical cross-sectional view of the door closer, showing a second opening angle state. [Figure 5] Cross section CC of Figure 4. [Figure 6] 4 is a vertical cross-sectional view of the door closer, showing a third opening angle state. FIG. [Figure 7] DD cross section of Figure 6. [Figure 8] FIG. 4 is a vertical cross-sectional view of the door closer, showing the door in an open state. [Figure 9] EE cross section of Figure 8. [Figure 10] FIG. 2 is a perspective view showing a piston, a slider, and a spring support member of the door closer. [Figure 11] The slider of the door closer is shown, where (a) is a plan view, (b) is a cross-sectional view of (a) taken along the line FF, and (c) is a cross-sectional view of (b) taken along the line GG. [Figure 12] 11(a) is a front view showing a spring support member of the door closer, and (b) and (c) are cross-sectional views corresponding to FIG. 11(b) showing a slider and a spring support member. [Figure 13] 4 is a graph showing the amount of movement of the slider and piston of the door closer. [Figure 14] 3 is a graph showing the closing force of the door closer. DETAILED DESCRIPTION OF THE INVENTION

[0012] A door closer according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 14. As shown in FIG. 1, the door closer in this embodiment includes a door closer main body 1, a mounting plate 2, and an arm 3. The door closer is of a sliding type. The door closer main body 1 is attached to a door or a door frame. The door rotates, for example, around an axis in the vertical direction. For example, when the door closer main body 1 is attached to a door, a rail (not shown) extending in the left-right direction (horizontal direction) is attached to the door frame. The door closer in this embodiment is of a concealed type, and the door closer main body 1 is placed inside the door. The door closer main body 1 is screwed to the door via the mounting plate 2. The mounting plate 2 is screwed to the top surface of the door closer main body 1. The left-right direction is the direction along the surface of the door and is the radial direction with respect to the center of rotation of the door. The front-rear direction is the normal direction to the surface of the door.

[0013] 1 to 3 show the door closer when the door is in a fully closed state. The door closer main body 1 includes a housing 10, a main shaft 11, a piston 12, a first cam 13a and a second cam 13b, a pinion gear 14, a first roller 15a and a second roller 15b, a slider 16, a first spring 17, a second spring 18, and a third spring 19. The first roller 15a, the second roller 15b, and the slider 16 are cam followers. Although the first cam 13a and the second cam 13b are provided as cams, they do not need to be separated into upper and lower cams, and there may be only one cam. Similarly, there may also be only one roller.

[0014] The housing 10 has a rectangular parallelepiped shape that is long in the left-right direction as a whole. In Fig. 1, the right side as you face it will be simply referred to as the right side, and the left side as you face it will be simply referred to as the left side. In this embodiment, the rotation center of the door is located on the left side of the door closer main body 1, but it may also be located on the right side.

[0015] The housing 10 has one accommodation chamber 20 extending in the left-right direction. The accommodation chamber 20 contains the piston 12, the first roller 15a, the second roller 15b, the slider 16, the first spring 17, the second spring 18, and the third spring 19. End caps 21 are attached to both left and right ends of the accommodation chamber 20. The accommodation chamber 20 is filled with hydraulic oil. The mounting plate 2 is screwed to the housing 10. The inner surface of the housing 10 is the wall surface of the accommodation chamber 20. The wall surface of the accommodation chamber 20 is a circular peripheral surface in cross section except for the vicinity of the main shaft 11. The accommodation chamber 20 has a center line extending in the left-right direction. In a plan view such as that shown in FIG. 2, the main shaft 11, the piston 12, the first roller 15a, the second roller 15b, the slider 16, the first spring 17, the second spring 18, and the third spring 19 are arranged on the center line of the accommodation chamber 20. Therefore, the main shaft 11, piston 12, first roller 15a, second roller 15b, slider 16, first spring 17, second spring 18, and third spring 19 are located on the same line in the left-right direction in a plan view. Also, in a side view or a front view as shown in Figure 1, the piston 12, slider 16, first spring 17, second spring 18, and third spring 19 are located on the same line in the left-right direction and at the same height in the up-down direction. The vertical centers of the first roller 15a and second roller 15b are located on the center line of the accommodation chamber 20.

[0016] The main shaft 11 is rotatably supported by the housing 10. As shown in FIG. 1, the main shaft 11 is positioned to the left of the center of the housing 10 in the left-right direction. As shown in FIG. 2, the main shaft 11 is located approximately in the center of the housing 10 in the front-rear direction. The main shaft 11 rotates around an axis in the up-down direction. The upper end of the main shaft 11 protrudes upward from the housing 10 and also protrudes upward from the mounting plate 2. A first end of the arm 3 is attached to the upper end of the main shaft 11 so as not to rotate relative to the main shaft 11. A second end of the arm 3 engages with the rail described above. When the door rotates, the second end of the arm 3 slides left and right while being guided by the rail. The main shaft 11 rotates together with the arm 3 as the door opens and closes.

[0017] As shown in FIG. 3, a first bearing holder 23 and a second bearing holder 24 are attached to the top and bottom surfaces of the housing 10, respectively. The first bearing holder 23 and the second bearing holder 24 are each cylindrical. A first communication hole 27 is formed in the top surface of the housing 10. The first communication hole 27 opens upward. The first communication hole 27 communicates between the accommodating chamber 20 and the outside of the housing 10. The first communication hole 27 has an axis extending in the vertical direction. A female thread is formed in the first communication hole 27. A male thread is formed on the outer peripheral surface of the first bearing holder 23. The first bearing holder 23 is screwed into the first communication hole 27 from above.

[0018] Similarly, a second communication hole 28 is formed in the bottom surface of the housing 10. The second communication hole 28 opens downward. The second communication hole 28 communicates between the accommodating chamber 20 and the outside of the housing 10, and has an axis in the vertical direction. A female thread is formed in the second communication hole 28. A male thread is formed on the outer peripheral surface of the second bearing holder 24. The second bearing holder 24 is screwed into the second communication hole 28 from below. The first communication hole 27 and the second communication hole 28 are positioned coaxially, and the first bearing holder 23 and the second bearing holder 24 are positioned coaxially.

[0019] The first bearing holder 23 holds a first bearing 25 on its inner peripheral surface. The second bearing holder 24 holds a second bearing 26 on its inner peripheral surface. The first and second bearings 25, 26 are preferably needle bearings, and in particular, full-collo type needle bearings. The first bearing 25 has a larger diameter than the second bearing 26. The main shaft 11 is rotatably supported by the first bearing holder 23 and the second bearing holder 24 via the first bearing 25 and the second bearing 26, respectively. The lower end of the main shaft 11 does not protrude downward from the second bearing holder 24. The upper end of the main shaft 11 protrudes upward from the first bearing holder 23 by a predetermined length.

[0020] The main shaft 11 will be further described in detail. As shown in FIG. 3, the main shaft 11 includes a first shaft member 31, a second shaft member 32, and a third shaft member 33. The first shaft member 31, the second shaft member 32, and the third shaft member 33 are separate from one another. The main shaft 11 is divided into upper and lower three sections. The first shaft member 31, the second shaft member 32, and the third shaft member 33 are connected to one another at the top and bottom. The first shaft member 31, the second shaft member 32, and the third shaft member 33 cannot rotate relative to one another, but rotate as a unit.

[0021] The first shaft member 31 is rotatably supported by the first bearing holder 23 via the first bearing 25. The lower part of the first shaft member 31 is supported by the first bearing holder 23, and the upper part of the first shaft member 31 protrudes upward from the first bearing holder 23. The upper end part of the first shaft member 31 is the upper end part of the main shaft 11. The arm 3 is fixed to the upper end part of the first shaft member 31. A screw hole 31a is formed in the upper end surface of the first shaft member 31 to attach the arm 3 to the first shaft member 31. The screw hole 31a has a predetermined depth and is a blind hole.

[0022] The first shaft member 31 protrudes downward beyond the first bearing holder 23. The lower end surface of the first shaft member 31 is located lower than the lower end surface of the first bearing holder 23. The first shaft member 31 has a first connecting hole 31b that opens downward. The first connecting hole 30b opens at the lower end surface of the first shaft member 31. The first connecting hole 31b extends in the up-down direction. The first connecting hole 31b does not communicate with the screw hole 31a. A first cam 13a is provided at the lower end of the first shaft member 31. The first cam 13a is formed integrally with the first shaft member 31, and the first shaft member 31 and the first cam 13a are a single member. However, the first cam 13a may be separate from the first shaft member 31.

[0023] The second shaft member 32 is rotatably supported by the second bearing holder 24 via the second bearing 26. The lower part of the second shaft member 32 is supported by the second bearing holder 24. The second shaft member 32 does not protrude downward from the second bearing holder 24. A second cam 13b is provided at the upper end part of the second shaft member 32. The second cam 13b is formed integrally with the second shaft member 32, and the second shaft member 32 and the second cam 13b are a single member. A second joining hole 32a is formed in the upper end surface of the second shaft member 32. However, the second cam 13b may be a separate member from the second shaft member 32.

[0024] The third shaft member 33 is disposed between the first shaft member 31 and the second shaft member 32. An upper portion of the third shaft member 33 is inserted into the first joining hole 31b of the first shaft member 31 so as to be non-rotatable relative to the first shaft member 31. A lower portion of the third shaft member 33 is inserted into the second joining hole 32a of the second shaft member 32 so as to be non-rotatable relative to the second shaft member 32. That is, the third shaft member 33 rotates integrally with the first shaft member 31 and the second shaft member 32. A pinion gear 14 is provided on the third shaft member 33. The pinion gear 14 is integrally formed on the outer peripheral surface of the third shaft member 33. The pinion gear 14 has teeth only within a predetermined angular range of the entire circumference of its outer peripheral surface, and no teeth are formed in other regions. That is, the outer peripheral surface of the pinion gear 14 is divided into a toothed region where teeth are formed and a non-toothed region where teeth are not formed and which is a smooth surface.

[0025] The first cam 13a and the second cam 13b are spaced apart from each other vertically, and the pinion gear 14 is located between the first cam 13a and the second cam 13b. The first cam 13a and the second cam 13b are arranged symmetrically in the vertical direction with respect to the pinion gear 14. The first cam 13a is located above the pinion gear 14, and the second cam 13b is located below the pinion gear 14. The outer peripheral surfaces of the first cam 13a and the second cam 13b are cam surfaces, each of which has the same shape. The cam surfaces of the first cam 13a and the second cam 13b are approximately heart-shaped.

[0026] The first cam 13a and the second cam 13b compress the first spring 17 during the door opening operation, and receive the elastic restoring force from the first spring 17 during the door closing operation. The elastic restoring force of the first spring 17 is transmitted to the main shaft 11 via the first cam 13a and the second cam 13b, and becomes a closing force for closing the door. During the door opening and closing operation, only a predetermined angular region of the entire circumference of the first cam 13a and the second cam 13b is used.

[0027] A pair of upper and lower rollers, a first roller 15a and a second roller 15b, and a slider 16 are disposed to the right of the first cam 13a and the second cam 13b. The first roller 15a, the second roller 15b, and the slider 16 are positioned between the first spring 17 and the first cam 13a and the second cam 13b. The first roller 15a and the second roller 15b are disposed to the left of the slider 16. The first roller 15a and the second roller 15b correspond to the first cam 13a and the second cam 13b and are spaced apart from each other vertically. The first roller 15a and the second roller 15b abut against the first cam 13a and the second cam 13b, respectively. The first roller 15a and the second roller 15b are fixed to a support shaft 40. The first roller 15a and the second roller 15b rotate integrally with the support shaft 40. The support shaft 40 has an axis extending in the vertical direction. The support shaft 40 is rotatably supported on the left portion of the slider 16. The first roller 15a, the second roller 15b and the slider 16 are connected via the support shaft 40 and move together in the left-right direction.

[0028] As shown in FIGS. 10 and 11 , the slider 16 has, from right to left, a first cylindrical portion 41, a second cylindrical portion 42, and a shaft support portion 43. The first cylindrical portion 41 and the second cylindrical portion 42 are cylindrical. The second cylindrical portion 42 is continuous with the left side of the first cylindrical portion 41, and the shaft support portion 43 is continuous with the left side of the second cylindrical portion 42. The outer peripheral surface of the first cylindrical portion 41 abuts against and is supported by the wall surface of the accommodation chamber 20. When the slider 16 moves in the left-right direction, the outer peripheral surface of the first cylindrical portion 41 is guided by the wall surface of the accommodation chamber 20 and slides along the wall surface of the accommodation chamber 20. A groove 44 through which hydraulic oil passes is formed in the outer peripheral surface of the first cylindrical portion 41. The groove 44 is formed over the entire length of the outer peripheral surface of the first cylindrical portion 41 in the left-right direction. In this embodiment, the groove 44 is formed linearly along the left-right direction, but it may be formed at an angle with respect to the left-right direction. Although a pair of grooves 44 are provided, one above the other, the number and arrangement thereof are optional.

[0029] A restricting pin 45 is attached to the housing 10, with its tip protruding into the accommodation chamber 20. The tip of the restricting pin 45 engages with the groove 44, thereby restricting rotation of the first cylindrical portion 41 around its axis relative to the housing 10. The restricting pin 45 functions as a rotation stopper for the slider 16. A locking pin 46 is attached to the right end surface of the first cylindrical portion 41. The end of the locking pin 46 protrudes from the right end surface of the first cylindrical portion 41, and the first spring 17 is locked to this protruding portion.

[0030] The second cylindrical portion 42 has a smaller diameter than the first cylindrical portion 41 and is arranged coaxially with the first cylindrical portion 41. A pair of upper and lower guide holes 47 that are long in the left-right direction are formed in the left portion (a predetermined region on the left side) of the second cylindrical portion 42. The guide holes 47 are elongated holes. The upper and lower guide holes 47 are positioned facing each other vertically. The guide holes 47 are arranged away from the first cylindrical portion 41 on the left side.

[0031] A first storage hole 48 and a second storage hole 49 are provided on the inside (radially inner side) of the first cylindrical portion 41 and the second cylindrical portion 42. The first storage hole 48 is located to the right of the second storage hole 49, and the first storage hole 48 and the second storage hole 49 are in communication with each other. The first storage hole 48 and the second storage hole 49 are coaxial with each other, extend along the left-right direction, and are located on the center lines of the first cylindrical portion 41 and the second cylindrical portion 42. The first storage hole 48 is provided in the first cylindrical portion 41. Most of the second storage hole 49 is provided in the second cylindrical portion 42. The first storage hole 48 opens to the right end of the first cylindrical portion 41. The first storage hole 48 has a larger diameter than the second storage hole 49. A step portion 50 is provided between the first storage hole 48 and the second storage hole 49. The upper and lower guide holes 47 each communicate with the second storage hole 49.

[0032] The shaft support portion 43 protrudes toward the left side from the second cylindrical portion 42. The shaft support portion 43 is plate-shaped with its thickness extending vertically. A through hole 51 is formed in the shaft support portion 43 along the vertical direction. The support shaft 40 is inserted into the through hole 51. The support shaft 40 is rotatably supported by the shaft support portion 43 via a bearing. The first rollers 15a and the second rollers 15b are arranged symmetrically above and below the shaft support portion 43. The first rollers 15a and the second rollers 15b are provided at the upper and lower ends of the support shaft 40, respectively. In this embodiment, the first roller 15a is separate from the support shaft 40 and is screwed to the support shaft 40, while the second roller 15b is formed integrally with the support shaft 40. However, both the first rollers 15a and the second rollers 15b may be separate from the support shaft 40.

[0033] <Spring support member 60> The spring support member 60 is disposed inside the slider 16. The spring support member 60 is inserted into the slider 16 through an opening. The spring support member 60 is movable left and right relative to the slider 16. As shown in FIG. 12, the spring support member 60 is coaxial with the slider 16. Note that in FIGS. 12(b) and 12(c), the spring support member 60 is indicated by multiple dots. The spring support member 60 is cylindrical overall. The spring support member 60 has a first shaft portion 61, a second shaft portion 62 connected to the left side of the first shaft portion 61, and a flange portion 63 connected to the right side of the first shaft portion 61. The first shaft portion 61 is the main portion of the spring support member 60. The first shaft portion 61 and the second shaft portion 62 are housed in the second storage hole 49 of the slider 16. The outer circumferential surface of the first shaft portion 61 slides against the wall surface of the second storage hole 49. The first shaft portion 61 is guided by the wall surface of the second storage hole 49 and moves in the left-right direction relative to the slider 16 .

[0034] The flange portion 63 has a larger diameter than the first shaft portion 61. As shown in FIG. 12(b), the first shaft portion 61 abuts against the step portion 50 of the slider 16 from the right side. When the first shaft portion 61 abuts against the step portion 50, the spring support member 60 is prevented from moving to the left relative to the slider 16. The flange portion 63 has the same diameter as the first storage hole 48 or a slightly smaller diameter than the first storage hole 48. The outer peripheral surface of the flange portion 63 may be guided by the wall surface of the first storage hole 48. It is preferable that a protrusion 64 protrudes from the right side of the flange portion 63. The protrusion 64 has a smaller diameter than the flange portion 63. The protrusion 64 is located on the central axis of the spring support member 60.

[0035] The second shaft portion 62 has a smaller diameter than the first shaft portion 61. As shown in FIG. 12(b), when the flange portion 63 abuts against the step portion 50, the left end of the second shaft portion 62 is located inside the upper and lower guide holes 47. In this embodiment, the entire second shaft portion 62 is located inside the guide hole 47. FIG. 12(c) shows a state in which the flange portion 63 is separated from the step portion 50 to the right. In this manner, the spring support member 60 is movable relative to the slider 16.

[0036] A first spring 17 is disposed on the right side of the slider 16. The first spring 17 generates a closing force for closing the door. The first spring 17 biases the slider 16, the first roller 15a, and the second roller 15b to the left. The first spring 17 is a coil spring and a compression spring. The first spring 17 is interposed between the slider 16 and the spring retainer 70. The left end of the first spring 17 abuts against the right end surface of the first cylindrical portion 41. The left end of the first spring 17 is engaged with the locking pin 46, which restricts the rotation of the first spring 17. The spring retainer 70 is located on the right side of the first spring 17. The right end of the first spring 17 abuts against the spring retainer 70. The locking pin 46 is attached to the left end surface of the spring retainer 70. The right end of the first spring 17 is locked to the locking pin 46, and the locking pin 46 restricts the relative rotation between the first spring 17 and the spring presser 70.

[0037] The spring retainer 70 is guided by the wall surface of the accommodation chamber 20 and is movable in the left-right direction. An adjustment shaft 71 passes through the spring retainer 70 in the left-right direction. The adjustment shaft 71 has a male thread portion that is screwed into the female thread portion of the spring retainer 70. The spring retainer 70 can be moved in the left-right direction by rotating the adjustment shaft 71. When the spring retainer 70 moves to the left, the first spring 17 is compressed and the spring force becomes stronger. Conversely, when the spring retainer 70 moves to the right, the amount of compression of the first spring 17 decreases and the spring force becomes weaker.

[0038] The adjustment shaft 71 penetrates the right end cap 22. The adjustment shaft 71 is rotatably supported by the end cap 22. The right end of the adjustment shaft 71 protrudes outside the end cap 22, and a first adjustment gear 72 is attached to that right end. The first adjustment gear 72 meshes with a second adjustment gear (not shown). The second adjustment gear is located below the mounting plate 2. An operating shaft (not shown) is rotatably supported by the mounting plate 2. The second adjustment gear is attached to the lower end of the operating shaft. The second adjustment gear can be rotated by rotating the operating shaft from above the mounting plate 2. Rotating the first adjustment gear 72 via the second adjustment gear rotates the adjustment shaft 71, thereby moving the spring retainer 70 in the left-right direction. In this embodiment, the spring retainer 70, the adjustment shaft 71, the first adjustment gear 72, the second adjustment gear, and the operating shaft constitute a spring force adjustment mechanism.

[0039] <Second spring 18> The second spring 18 is coaxially arranged inside the first spring 17. The second spring 18 is a compression coil spring. The second spring 18 has a smaller diameter and weaker spring force than the first spring 17. The left end of the second spring 18 is inserted into the first storage hole 48. The left end of the second spring 18 abuts against the flange portion 63 of the spring support member 60. The protrusion 64 of the spring support member 60 fits inside the second spring 18. A spring retainer 71a is formed at the left end of the adjustment shaft 71. The spring retainer 71a is annular. The right end of the second spring 18 abuts against the spring retainer 71a. The second spring 18 is interposed between the spring support member 60 and the spring retainer 71a. The second spring 18 biases the spring support member 60 leftward.

[0040] The accommodation chamber 20 accommodates a foam rubber 73. The foam rubber 73 is for absorbing expansion caused by a rise in temperature of the hydraulic oil. The foam rubber 73 is, for example, rod-shaped. The foam rubber 73 is, for example, disposed inside the second spring 18.

[0041] <Piston 12> The housing 10 is provided with a flow control passage 74 for controlling the door-closing speed. The piston 12 buffers the door-closing action by forcing hydraulic oil into the flow control passage 74 during the door-closing action. The piston is long in the left-right direction. The piston 12 has a first head portion 80 at its left end. The first head portion 80 is located to the left of the main shaft 11. The first head portion 80 is cylindrical with its axis in the left-right direction. The outer circumferential surface of the first head portion 80 has approximately the same diameter as the wall surface of the accommodation chamber 20, and is supported by the wall surface of the accommodation chamber 20. When the piston 12 moves, the outer circumferential surface of the first head portion 80 slides against the wall surface of the accommodation chamber 20.

[0042] A through-hole 81 is formed in the center of the first head portion 80 along the left-right direction. This through-hole 81 is provided with a check valve. During the door-opening operation, the piston 12 moves to the right. During the door-opening operation, a ball 82, which serves as the valve body of the check valve, moves to the left, opening the valve and allowing hydraulic oil to pass through the through-hole 81. On the other hand, during the door-closing operation, the piston 12 moves to the left. During the door-closing operation, the ball 82 of the check valve is pushed to the right by the hydraulic pressure of the hydraulic oil, closing the through-hole 81 and preventing hydraulic oil from passing through the through-hole 81. During the door-closing operation, the hydraulic oil pushed to the left by the piston 12 is forced into the flow control flow path 74, which serves as a bypass. The hydraulic oil travels through the flow control flow path 74 to an area to the right of the first head portion 80. An adjustment valve (not shown) is provided in the flow control flow path 74 to control the flow rate of the hydraulic oil flowing through the flow control flow path 74. The adjustment valve is adjustable from the top of the housing 10. By controlling the flow rate of the hydraulic oil flowing through the flow rate control passage 74, the degree of cushioning during the door closing operation can be adjusted.

[0043] The piston 12 has a pair of front and rear arms 83 on the right side of the first head portion 80. The pair of arms 83 are parallel to each other. The outer surfaces of the arms 83 are curved in an arc-like shape in cross section. The outer surfaces of the arms 83 slide against the wall surfaces of the storage chamber 20. The arms 83 extend linearly in the left-right direction. The arms 83 extend beyond the main shaft 11 to the right. A rack 84 is formed on the inner surface of one of the arms 83. The rack 84 meshes with the pinion gear 14. The pinion gear 14 and the rack 84 form a rack-and-pinion mechanism. When the main shaft 11 rotates in conjunction with the opening and closing of the door, the pinion gear 14 moves the piston 12 in the left-right direction. When the main shaft 11 rotates in conjunction with the opening and closing of the door, the first roller 15a, the second roller 15b, the slider 16, and the piston 12 all move in the same direction.

[0044] The piston 12 has a second head portion 85 at its right end. The arm portion 83 connects the first head portion 80 and the second head portion 85. The second head portion 85 is cylindrical. The second head portion 85 has a center line along the left-right direction. The outer circumferential surface of the second head portion 85 has approximately the same diameter as the wall surface of the accommodation chamber 20, and is supported by the wall surface of the accommodation chamber 20. When the piston 12 moves, the outer circumferential surface of the second head portion 85 slides on the wall surface of the accommodation chamber 20.

[0045] The slider 16 passes inside the second head portion 85 and partially enters the piston 12 from the right side. Specifically, the shaft support portion 43 and the second cylindrical portion 42 of the slider 16 enter the inside of the piston 12. The second head portion 85 covers the radially outer side of the second cylindrical portion 42. The inner circumferential surface of the second head portion 85 has approximately the same diameter as the outer circumferential surface of the second cylindrical portion 42. The outer circumferential surface of the second cylindrical portion 42 is supported by the inner circumferential surface of the second head portion 85.

[0046] As shown in Figure 10, the second head portion 85 has a through hole 86 that penetrates in the vertical direction. A support pin 87 is inserted and fixed in the through hole 86. The support pin 87 is inserted in the vertical direction through a pair of upper and lower guide holes 47 of the first cylindrical portion 41. The support pin 87 prevents relative rotation between the piston 12 and the slider 16. When the piston 12 moves relative to the slider 16, the support pin 87 moves in the left-right direction within the guide holes 47 of the slider 16.

[0047] <Third Spring 19> A third spring 19 is disposed between the second head portion 85 of the piston 12 and the first cylindrical portion 41 of the slider 16. The third spring 19 is a coil spring and a compression spring. The third spring 19 is weaker than the first spring 17. The third spring 19 is shorter than the first spring 17 and shorter than the second spring 18. The third spring 19 is located outside the second cylindrical portion 42 of the slider 16. The second cylindrical portion 42 passes through the inside of the third spring 19. The third spring 19 is disposed coaxially with the second cylindrical portion 42, i.e., coaxially with the slider 16.

[0048] <Door closed> 1 and 2 show the closed door state. In the closed door state, the spring support member 60 is biased leftward by the second spring 18. The flange portion 63 of the spring support member 60 abuts against the stepped portion 50 of the slider 16, preventing the spring support member 60 from moving further leftward relative to the slider 16. A predetermined length region on the left end side of the spring support member 60 is positioned inside the guide hole 47. The support pin 87 is positioned at the left portion of the entire length of the guide hole 47, and the second head portion 85 is positioned at the left end of the second cylindrical portion 42. In the closed door state, the support pin 87 is spaced to the left from the spring support member 60. Specifically, the support pin 87 is spaced to the left from the second shaft portion 62 of the spring support member 60. The third spring 19 is not compressed and is in an uncompressed state. The free length of the third spring 19 is short compared to the left-right distance between the second head portion 85 and the first cylindrical portion 41. Therefore, in the closed door state, a gap exists between the third spring 19 and the second head portion 85, or between the third spring 19 and the first cylindrical portion 41. Although FIGS. 1 and 2 show the third spring 19 in contact with the first cylindrical portion 41, the third spring 19 can move left and right between the second head portion 85 and the first cylindrical portion 41. The distance between the second head portion 85 and the first cylindrical portion 41 may be the same as the free length of the third spring 19. Alternatively, the distance between the second head portion 85 and the first cylindrical portion 41 may be shorter than the free length of the third spring 19. In other words, in the closed door state, the third spring 19 may already be compressed by a predetermined amount.

[0049] <Door opening action> As the door is opened, the main shaft 11 rotates together with the arm 3. The first cam 13a and the second cam 13b rotate together with the main shaft, and the first cam 13a and the second cam 13b move the first roller 15a, the second roller 15b, and the slider 16 to the right. The slider 16 presses and compresses the first spring 17. In other words, the first cam 13a and the second cam 13b compress the first spring 17 via the first roller 15a, the second roller 15b, and the slider 16. The first cam 13a and the second cam 13b significantly compress the first spring 17, especially at the beginning of opening.

[0050] Furthermore, when the slider 16 moves to the right, the spring support member 60 also moves to the right together with the slider 16, as if being pushed by the slider 16. That is, the slider 16 and the spring support member 60 move together until the support pin 87 abuts against the spring support member 60. The movement of the spring support member 60 to the right compresses the second spring 18. The first cam 13a and the second cam 13b cause the spring support member 60 to significantly compress the second spring 18, especially at the beginning of opening.

[0051] Meanwhile, as the pinion gear 14 rotates, the piston 12 also moves to the right. That is, when the main shaft rotates, the slider 16 and the piston 12 move by different mechanisms. As will be described later, the slider 16 moves more than the piston 12 at the beginning of opening, but at a first opening angle, the slider 16 and the piston 12 move the same distance. Then, once the opening exceeds the first opening angle, the piston 12 moves more than the slider 16.

[0052] FIG. 13 shows the relationship between the door opening angle (rotation angle of the main shaft) and the amount of movement of the slider 16 and the piston 12. The slider 16 moves significantly at the beginning of opening, but thereafter, the amount of movement of the slider 16 increases little, and the rate of increase converges. On the other hand, the piston 12 moves in proportion to the door opening angle. In the section from the closed door state (fully closed state) to the first opening angle, the amount of movement of the slider 16 is greater than the amount of movement of the piston 12. Therefore, in the section from the closed door state (fully closed state) to the first opening angle, the distance between the second head portion 85 and the first cylindrical portion 41 is greater than in the closed door state. Then, once the first opening angle is exceeded, the amount of movement of the piston 12 is greater than the amount of movement of the slider 16. The second opening angle and third opening angle described below are both greater than the first opening angle.

[0053] <Second opening angle> 4 and 5 show the state in which the door is opened to the second opening angle. When the door is opened to the second opening angle, the gap between the third spring 19 and the second head portion 85 and the first cylindrical portion 41 disappears, and the third spring 19 abuts against the second head portion 85 and the first cylindrical portion 41. That is, the free length of the third spring 19 is equal to the distance between the second head portion 85 and the first cylindrical portion 41. At the second opening angle, the support pin 87 does not yet abut against the spring support member 60. The second opening angle is larger than the first opening angle. Therefore, as shown in FIG. 13, at the second opening angle, the piston 12 moves to the right by a greater distance than the slider 16. When the door is opened beyond the second opening angle, the second head portion 85 pushes the third spring 19 to the right, compressing it.

[0054] <Third opening angle> The third opening angle is larger than the second opening angle. The support pin 87 does not abut against the spring support member 60 until the door reaches the third opening angle. In the section from the closed door state to the third opening angle, the spring support member 60 moves to the right together with the slider 16. In the section from the closed door state to the third opening angle, the first cam 13a and the second cam 13b press and compress the second spring 18 via the first roller 15a, the second roller 15b, the slider 16, and the spring support member 60.

[0055] 6 and 7 show the state in which the door is opened to the third opening angle. When the door reaches the third opening angle, the support pin 87 abuts against the spring support member 60. When the opening angle of the door exceeds the third opening angle, the support pin 87 presses against the spring support member 60. The flange portion 63 of the spring support member 60 moves away from the stepped portion 50 of the slider 16, and the spring support member 60 moves to the right relative to the slider 16. The second spring 18 is pressed by the piston 12 via the spring support member 60 and compressed. In this way, at the third opening angle, the member compressing the second spring 18 switches from the first cam 13a and the second cam 13b to the piston 12.

[0056] <Fully open state (door open state)> 8 and 9 show the state in which the door is fully opened. From the third opening angle until just before the fully opened state, the third spring 19 is compressed by the movement of the piston 12. The second spring 18 is also compressed by the piston 12. In the fully opened state, the support pin 87 approaches the right end of the guide hole 47. Alternatively, the support pin 87 may be located at the right end of the guide hole 47. The flange portion 63 of the spring support member 60 remains in the first storage hole 48 of the slider 16 and does not protrude to the right from the first cylindrical portion 41. In the fully opened state, as shown in FIG. 9, the pinion gear 14 and the rack 84 no longer mesh, and the teeth of the pinion gear 14 are disengaged from the rack 84. Therefore, even if the door is opened beyond the fully opened position and the main shaft 11 rotates, the pinion gear 14 rotates freely, the piston 12 does not move to the right, and the spring support member 60 does not move to the right either.

[0057] <Door closing operation> As the door closes from the fully open state, the teeth of the pinion gear 14 mesh with the rack 84, and the piston 12 begins to move to the left. The first spring 17 applies an elastic restoring force to the first cam 13a and the second cam 13b via the slider 16. The second spring 18 applies an elastic restoring force to the piston 12 via the spring support member 60. The third spring 19 applies an elastic restoring force to the piston 12. The elastic restoring force of the first spring 17 is transmitted from the first cam 13a and the second cam 13b to the main shaft 11. The elastic restoring forces of the second spring 18 and the third spring 19 are transmitted from the piston 12 to the main shaft 11 via the rack 84 and the pinion gear 14. These resultant forces rotate the main shaft 11, which then acts as a closing force on the door, causing the door to close automatically.

[0058] In the section from the fully open state to the third opening angle, the elastic restoring force of the first spring 17 acts on the first cam 13a and the second cam 13b. However, since the movement amount of the slider 16 is small as shown in Figure 13, the first spring 17 hardly contributes to the closing force. On the other hand, the elastic restoring forces of the second spring 18 and the third spring 19 act on the piston 12. Since the movement amount of the piston 12 is large as shown in Figure 13, the door is mainly closed by the piston 12 in this section.

[0059] In the section from the third opening angle to the second opening angle, the first spring 17 continues to make almost no contribution to the closing force. The elastic restoring force of the second spring 18 acts on the first cam 13a and the second cam 13b via the spring support member 60 and the slider 16. Again, because the movement amount of the slider 16 is small, the second spring 18 makes almost no contribution to the closing force. Meanwhile, the elastic restoring force of the third spring 19 continues to act on the piston 12. Therefore, even in this section, the door is closed mainly by the piston 12.

[0060] In the section from the second opening angle to the first opening angle, the movement amount of the slider 16 increases, so that the first spring 17 and the second spring 18 gradually contribute to the closing force. On the other hand, the third spring 19 returns to its free length at the second opening angle, so the third spring 19 does not contribute to the closing force.

[0061] The section from the first opening angle to the fully closed state is the closing section. In this section, the movement of the slider 16 is maximized due to the setting of the approximately heart-shaped cam surface. Therefore, the elastic restoring forces of the first spring 17 and the second spring 18 are transmitted from the first cam 13a and the second cam 13b to the main shaft 11 as a closing force, and the door is closed. Meanwhile, since the third spring 19 has already returned to its free length, the third spring 19 does not contribute to the closing force. Thus, when closing, the elastic restoring forces of the first spring 17 and the second spring 18 act as a resultant force on the first cam 13a and the second cam 13b, generating a closing force.

[0062] As described above, when the door is closed, the elastic restoring force of the third spring 19 acts on the piston 12 in addition to the elastic restoring force of the second spring 18. Therefore, insufficient closing force is unlikely to occur, and the door can be stably closed with a large closing force. Furthermore, since the third spring 19 is disposed between the piston 12 and the slider 16, the third spring 19 can be easily disposed in the accommodation chamber 20. By utilizing the difference in the amount of movement between the piston 12 and the slider 16, the third spring 19 can be effectively compressed when the door is opened. In other words, the third spring 19 can be compressed by the relative movement of the piston 12 with respect to the slider 16. Then, when the door is closed, the closing force of the third spring 19 can be effectively applied to the piston 12. In particular, the third spring 19 is arranged between the second head portion 85 of the piston 12 and the first cylindrical portion 41 of the slider 16, and the second cylindrical portion 42 of the slider 16 is inserted inside the third spring 19, so that the third spring 19 can be reliably compressed by the second head portion 85 of the piston 12 and the first cylindrical portion 41 of the slider 16.

[0063] Furthermore, since the piston 12 does not compress the third spring 19 in the section from the closed door state to the second opening angle, the compression section of the third spring 19 can be shortened. This simplifies the design of the third spring 19 and improves the durability of the third spring 19. Furthermore, the closing force of the third spring 19 can be effectively applied to the door at a relatively large opening angle. In particular, since the separation distance between the piston 12 and the cam follower is greater than the free length of the third spring 19 in the closed door state, the section in which the third spring 19 is compressed can be easily shortened, and the arrangement of the piston 12 and the slider 16 also becomes easier.

[0064] Furthermore, in the section from the third opening angle to the closed state, the elastic restoring force of the second spring 18 acts on the first cam 13a and the second cam 13b in addition to the elastic restoring force of the first spring 17. Therefore, particularly when closing, a large closing force can be applied to the door from the first cam 13a and the second cam 13b via the main shaft 11, making it less likely that insufficient closing force will occur when closing, and the door can be closed securely.

[0065] In particular, since the spring support member 60 is provided so as to be movable relative to the slider 16, the member that compresses the second spring 18 at the third opening angle can be easily switched from the first cam 13a and the second cam 13b to the piston 12. Furthermore, since the support pin 87 of the piston 12 abuts against the spring support member 60 at the third opening angle, the member that compresses the second spring 18 can be easily switched from the first cam 13a and the second cam 13b to the piston 12 at the third opening angle.

[0066] In this way, by providing the third spring 19, the closing force is strengthened in the angular region where the closing force is generated mainly by the piston 12. Furthermore, since the closing force is applied to the first cam 13a and the second cam 13b from the second spring 18 in addition to the first spring 17, the closing force is strengthened especially when closing.

[0067] FIG. 14 conceptually illustrates the relationship between the door opening angle and the closing force. P3 represents the case where only the first spring 17 is provided. Because the elastic restoring force of the first spring 17 acts only on the first cam 13a and the second cam 13b, in one example, the closing force becomes zero at approximately 55 degrees, and no closing force is generated at opening angles greater than this. P2 represents the case where the third spring 19 is not provided, but only the first spring 17 and the second spring 18 are provided. As in this embodiment, the first cam 13a, the second cam 13b, and the piston 12 compress the second spring 18. In this case, because the second spring 18 is provided, a closing force is generated by the second spring 18 even at opening angles greater than approximately 55 degrees. Furthermore, in the range of approximately 55 degrees or less, the second spring 18, in addition to the first spring 17, also exerts an elastic restoring force on the first cam 13a and the second cam 13b, resulting in a stronger closing force than P3 with only the first spring 17. P1 is the case of this embodiment, in which a third spring 19 is provided in addition to the first spring 17 and the second spring 18, and the second spring 18 is compressed by the first cam 13a, the second cam 13b, and the piston 12. Compared to P2, in the case of P1, the third spring 19 is added, so the closing force is increased at opening angles of approximately 55 degrees or more.

[0068] In this embodiment, the member compressing the second spring 18 is switched from the first cam 13a and the second cam 13b to the piston 12 during the door-opening operation, but this does not have to be the case. That is, the piston 12 may compress the second spring 18 throughout the entire door-opening operation. Also, the third spring 19 may be disposed on the right side of the spring support member 60, for example. [Explanation of symbols]

[0069] 1 Door closer body 2 Mounting Plate 3 Arm 10. Housing 11 Spindle 12 pistons 13a First Cam 13b Second Cam 14 Pinion gear 15a First roller (cam follower) 15b Second roller (cam follower) 16 Slider (cam follower) 17 First Spring 18 Second spring 19 Third spring 20 Containment Room 21 End cap 23 First bearing holder 24 Second bearing holder 25 First bearing 26 Second bearing 27 First series of holes 28 Second communication hole 31 First shaft member 31a screw hole 31b First joint hole 32 Second shaft member 32a Second joint hole 33 Third shaft member 40 Spindle 41 First cylinder part 42 Second cylinder part 43 Shaft support part 44 Groove 45 Regulatory pin 46 Locking pin 47 Guide hole 48 First storage hole 49 Second storage hole 50 Step 51 Through hole 60 Spring support member 61 First shaft part 62 Second shaft part 63 Flange 64 Convex part 70 Spring holder 71 Adjustment axis 71a Spring holder 72 First adjusting gear 73 Foam rubber 74 Flow control channel 80 First head section 81 Through hole 82 balls 83 Arm 84 racks 85 Second head 86 Through Hole 87 Support pin

Claims

1. a main shaft that rotates around an axis in a predetermined direction in accordance with the opening and closing operation of the door; a cam provided on the main shaft and rotating together with the main shaft; a piston that moves in a direction perpendicular to the predetermined direction by a rack and pinion mechanism in accordance with the rotation of the main shaft; a first spring that elastically deforms when the door is opened and restores its original shape when the door is closed, generating a closing force; a second spring that is provided separately from the first spring, elastically deforms when the door is opened, and restores its original shape when the door is closed, generating a closing force; a third spring that is provided separately from the first spring and the second spring, elastically deforms when the door is opened, and restores its original shape when the door is closed, generating a closing force; a cam follower that is disposed between the cam and the first spring and moves in a direction perpendicular to the predetermined direction as the cam rotates; A third spring is placed between the piston and the cam follower. A door closer in which, when the door is opened, the cam elastically deforms the first spring, and the piston elastically deforms the second and third springs.

2. A main shaft that rotates around an axis in a predetermined direction in accordance with the opening and closing operation of the door; a cam provided on the main shaft and rotating together with the main shaft; a piston that moves in a direction perpendicular to the predetermined direction by a rack and pinion mechanism in accordance with the rotation of the main shaft; a first spring that elastically deforms when the door is opened and restores its original shape when the door is closed, generating a closing force; a second spring that is provided separately from the first spring, elastically deforms when the door is opened, and restores its original shape when the door is closed, generating a closing force; a third spring that is provided separately from the first spring and the second spring, elastically deforms when the door is opened, and restores its original shape when the door is closed, generating a closing force; When the door is opened, the cam elastically deforms the first spring, and the piston elastically deforms the second and third springs. The piston does not elastically deform the third spring from the closed state until the door reaches a predetermined opening angle, and elastically deforms the third spring when the door exceeds the predetermined opening angle.

3. 3. The door closer according to claim 2, wherein in the door closed state, a distance between the piston and the cam follower is greater than a free length of the third spring.

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