Door closer

Abstract

To prevent damage of teeth of a rack-and-pinion mechanism.SOLUTION: A pinion gear 14 includes a reference pinion tooth 100, and an expanded pinion tooth 110 in which a pitch circle is the same as the reference pinion tooth 100 and tooth thickness is larger than the reference pinion tooth 100. A rack 74 includes a reference rack tooth 200, and an expanded rack tooth 210 in which a pitch line is the same as the reference rack tooth 200 and tooth thickness is larger than the reference rack tooth 200. The reference pinion tooth 100 and the reference rack tooth 200 are engaged with each other in a relatively small door opening angle, and the expanded pinion tooth 110 and the expanded rack tooth 210 are engaged with each other in a relatively large door opening angle.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to a door closer equipped with a rack and pinion mechanism. [Background technology]

[0002] The door closer described in Patent Document 1 below has a rack-and-pinion mechanism. The pinion gear of the main shaft meshes with the rack of the piston. When the main shaft rotates with the door-opening operation, the piston moves and compresses the spring, and the stored spring force becomes the closing force for closing the door. This closing force acts on the teeth of the pinion and the teeth of the rack. Therefore, when a large force acts on the teeth of the pinion gear and the rack, such as when the door is wide open, there is a risk that the teeth of the pinion gear and the teeth of the rack may be damaged. In particular, when the door closer is made small, the teeth are more likely to be damaged when a large force acts on them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3113961 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to prevent damage to the teeth of a rack and pinion mechanism. [Means for solving the problem]

[0005] The door closer of the present invention comprises a main shaft that rotates in conjunction with the opening and closing operations of the door, a spring that is charged when the door is opened and applies a closing force to the main shaft when the door is closed, a pinion gear that rotates integrally with the main shaft, and a piston that has a rack that meshes with the pinion gear and moves with the rotation of the main shaft to charge the spring when the door is opened and transmit the closing force of the spring to the main shaft when the door is closed, the pinion gear has reference pinion teeth and extended pinion teeth having the same pitch circle as the reference pinion teeth and a larger tooth thickness than the reference pinion teeth, the rack has reference rack teeth and extended rack teeth having the same pitch line as the reference rack teeth and a larger tooth thickness than the reference rack teeth, the reference pinion teeth and the reference rack teeth mesh at a relatively small door opening angle, and the extended pinion teeth and extended rack teeth mesh at a relatively large door opening angle.

[0006] According to this configuration, in addition to the reference pinion teeth and reference rack teeth with a reference tooth thickness, the extended pinion teeth and extended rack teeth with a large tooth thickness are provided. The reference pinion teeth and the reference rack teeth mesh with each other at a relatively small door-opening angle, and the extended pinion teeth and the extended rack teeth mesh with each other at a relatively large door-opening angle. Therefore, even in a situation where a large force is applied to the pinion gear and the rack, damage to the teeth of the pinion gear and the rack is prevented.

[0007] In addition, when the tooth width of the pinion gear and the rack (the axial dimension of the pinion gear) is increased, the axial dimension of the main shaft of the door closer is increased. On the other hand, by providing extended pinion teeth and extended rack teeth, it is possible to improve the strength without increasing the axial dimension of the main shaft of the door closer. However, the tooth width of the pinion gear and the rack may be increased together with providing extended pinion teeth and extended rack teeth.

[0008] In addition, since the extended pinion teeth have the same pitch circle as the reference pinion teeth, and the extended rack teeth have the same pitch line as the reference rack teeth, there is no need to excessively increase the dimensions of the pinion gear and the rack. This can prevent the door closer from increasing in size. Furthermore, since there is no need to change the pitch circle or pitch line, the pinion gear and the rack are easy to manufacture.

[0009] In particular, it is preferable that at the maximum door-opening angle, the reference pinion teeth and the reference rack teeth do not mesh, and the extended pinion teeth and the extended rack teeth mesh. At the maximum door-opening angle, a large force acts on the pinion gear and the rack. This force is due to the closing force of the spring. If the extended pinion teeth and the extended rack teeth mesh at the maximum door-opening angle, the large force can be easily absorbed by the extended pinion teeth and the extended rack teeth. Therefore, damage to the teeth, which is likely to occur at the maximum door-opening angle, can be effectively prevented.

[0010] In addition, it is preferable that the expanded pinion teeth and the expanded rack teeth mesh at the step angle, which is the door-opening angle at which the force acting on the pinion gear and the rack increases in a step-like manner while the door is opening. At the step angle, a large force acts on the pinion gear and the rack. If the expanded pinion teeth and the expanded rack teeth mesh at the step angle, the large force can be easily absorbed by the expanded pinion teeth and the expanded rack teeth. Therefore, damage to the teeth that is likely to occur at the step angle can be effectively prevented.

[0011] In particular, it is preferable that the expansion pinion teeth and the expansion rack teeth start to mesh at an expansion start angle, which is a door opening angle smaller than the step angle. With this configuration, when the door is opened, the expansion pinion teeth and the expansion rack teeth start to mesh at a stage before the step angle. Therefore, the expansion pinion teeth and the expansion rack teeth can reliably withstand a large force at the step angle, and damage to the teeth can be more reliably prevented.

[0012] Furthermore, it is preferable that the expansion pinion teeth and the expansion rack teeth continue to mesh with each other from the expansion start angle to the maximum door opening angle. With this configuration, damage to the teeth can be reliably prevented from the expansion start angle to the maximum door opening angle. Effect of the Invention

[0013] As described above, the expansion pinion teeth and the expansion rack teeth mesh with each other at a door-opening angle that is relatively larger than the reference pinion teeth and the reference rack teeth, so that damage to the pinion gear and the rack teeth can be prevented. [Brief description of the drawings]

[0014] [Figure 1] 1A and 1B are cross-sectional views showing a state in which the door opening angle of a door closer in one embodiment of the present invention is 0 degrees, where (a) is a cross-sectional view seen from the top side, and (b) is a cross-sectional view seen from the front side. [Diagram 2] 1(a) and (b) are enlarged views of the main parts of FIGS. 1(a) and (b), respectively. [Diagram 3] Cross section AA of Figure 2. [Figure 4] Cross-sectional view of FIG. 2 taken along line B-B. [Diagram 5] 4A and 4B are perspective views showing a main part of the door closer. [Figure 6] 1A and 1B show the piston of the door closer, where (a) is a plan view, (b) is a CC cross-sectional view of (a), and (c) is a DD cross-sectional view of (b). [Figure 7] 4A and 4B are cross-sectional views showing the state of the door closer when the door opening angle is 57 degrees, where (a) is a cross-sectional view seen from the top side and (b) is a cross-sectional view seen from the front side. [Figure 8] 4A and 4B are cross-sectional views showing the state of the door closer when the door opening angle is 70 degrees, where (a) is a cross-sectional view seen from the top side and (b) is a cross-sectional view seen from the front side. [Figure 9] 4A and 4B are cross-sectional views showing the state of the door closer when the door opening angle is 80 degrees, where (a) is a cross-sectional view seen from the top side and (b) is a cross-sectional view seen from the front side. [Figure 10] 4A and 4B are cross-sectional views showing the state of the door closer when the door opening angle is 125 degrees, where (a) is a cross-sectional view seen from the top side and (b) is a cross-sectional view seen from the front side. [Figure 11] The figure shows the state of the door closer when the door opening angle is 5 degrees, where (a) is a cross-sectional view of the main parts and (b) is a schematic diagram of the main parts. [Figure 12]1A and 1B are plan views showing main parts of the door closer, in which FIG. 1A shows a pinion gear and FIG. [Figure 13] 13 is a plan view showing the meshing state of the pinion gear and rack of the door closer, where (a) shows the state when the door-opening angle is 0 degrees, (b) shows the state when the door-opening angle is 57 degrees, and (c) shows the state when the door-opening angle is 70 degrees. [Figure 14] 1A and 1B are plan views showing the meshing state of the pinion gear and rack of the door closer, in which (a) shows the state where the door opening angle is 80 degrees, and (b) shows the state where the door opening angle is 125 degrees. [Figure 15] 5A and 5B are cross-sectional views of a door closer according to another embodiment of the present invention, as viewed from the top side, in which (a) shows a state in which the door opening angle is 0 degrees, and (b) shows a state in which the door opening angle is maximum. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A door closer according to an 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 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 a concealed type, and the door closer main body 1 is disposed 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 upper surface of the door closer main body 1. The left-right direction is a first orthogonal direction X perpendicular to the main shaft 11 described later, a direction along the surface of the door, and a radial direction with respect to the rotation center of the door. The front-rear direction is a second orthogonal direction Y perpendicular to the main shaft 11 and the left-right direction, and a normal direction to the surface of the door.

[0016] 1 and 2 show the door closer when the door opening angle is 0 degrees (when the door is fully closed). The door closer main body 1 includes a housing 10, a main shaft 11, a piston 12, a cam 13, a pinion gear 14 constituting a rack-and-pinion mechanism, a roller 15, a slider 16, a main coil spring 17, a sub-coil spring 18, and a spring force adjustment mechanism 19. The roller 15 and the slider 16 are cam followers.

[0017] 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 one faces the door will be simply referred to as the right side, and the left side as one faces the door will be simply referred to as the left side. In this embodiment, the rotation center of the door is located on the left side with respect to the door closer main body 1, but it may be located on the right side.

[0018] The housing 10 has one accommodation chamber 20 extending in the left-right direction. The accommodation chamber 20 contains the piston 12, the roller 15, the slider 16, the main coil spring 17, and the sub-coil spring 18. End caps 21, 22 are attached to both left and right ends of the accommodation chamber 20, respectively. Hydraulic oil is filled in the accommodation chamber 20. The mounting plate 2 is screwed to the housing 10. The accommodation chamber 20 has a center line CL extending in the left-right direction in a plan view. In the plan views of Figs. 1(a) and 2(a), the main shaft 11, the piston 12, the roller 15, the slider 16, the main coil spring 17, and the sub-coil spring 18 are arranged on the center line CL of the accommodation chamber 20. Therefore, the main shaft 11, the piston 12, the roller 15, the slider 16, the main coil spring 17, and the sub-coil spring 18 are positioned on the same line along the left-right direction in a plan view. However, the main shaft 11, rollers 15, etc. may be disposed with a positional deviation in the front-rear direction with respect to the center line CL. In addition, in a front view as shown in Fig. 1(b), the piston 12, slider 16, main coil spring 17, and sub coil spring 18 are positioned on the same line along the left-right direction and at the same height in the up-down direction.

[0019] The main shaft 11 is rotatably supported by the housing 10. As shown in FIG. 1, the main shaft 11 is disposed to the left of the center of the housing 10 in the left-right direction. As shown in FIG. 1(a) and FIG. 2(a), the main shaft 11 is located approximately in the center of the housing 10 in the front-rear direction, specifically, on the center line CL. 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 is engaged with the rail described above. When the door rotates, the second end of the arm 3 slides left-right while being guided by the rail. The main shaft 11 rotates together with the arm 3 as the door opens and closes.

[0020] 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. The first bearing holder 23 and the second bearing holder 24 are arranged coaxially. 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, are preferably full-coil 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.

[0021] The main shaft 11 is configured to be divided into two parts, an upper part and a lower part. The main shaft 11 includes a first shaft member 30 located on the upper side and a second shaft member 31 located on the lower side. The first shaft member 30 and the second shaft member 31 are separate from each other. The first shaft member 30 and the second shaft member 31 are connected to each other so that they cannot rotate relative to each other. The first shaft member 30 is supported by a first bearing 25. The arm 3 is screwed to the upper end of the first shaft member 30. The first shaft member 30 has a joint hole that opens to the lower side, and a vertical serration is formed in the joint hole. The shape and configuration of the vertical serration are arbitrary, but in this embodiment, it is a polygon, specifically a hexagon. The second shaft member 31 is inserted into this joint hole and connected to each other so that they cannot rotate relative to each other.

[0022] The second shaft member 31 is provided with a cam 13 and a pinion gear 14. A pair of upper and lower cams 13 are provided and are arranged spaced apart from each other vertically. The pinion gear 14 is located between the pair of upper and lower cams 13, and the cams 13 are arranged symmetrically with respect to the pinion gear 14 vertically. The cam 13 is separate from the second shaft member 31. However, the cam 13 may be formed integrally with the second shaft member 31. The pinion gear 14 is formed integrally with the second shaft member 31. However, the pinion gear 14 may be configured as a separate body from the second shaft member 31.

[0023] The pinion gear 14 is located at the vertical middle portion of the second shaft member 31. The pinion gear 14 is located at approximately the vertical center of the accommodation chamber 20. The pinion gear 14 meshes with a rack 74, which will be described later. The pinion gear 14 has teeth only in a predetermined angular range of the entire circumference of its outer circumferential surface.

[0024] The teeth of the pinion gear 14 are shown in detail in Fig. 12(a). The pinion gear 14 has pinion teeth arranged in parallel in the circumferential direction on its outer circumferential surface, and the pinion teeth include reference pinion teeth 100 and extended pinion teeth 110. The reference pinion teeth 100 have a standard tooth profile, and the extended pinion teeth 110 have a tooth profile different from the standard tooth profile. A pitch circle 120 is shown by a dashed line in Fig. 12(a). The reference pinion teeth 100 and the extended pinion teeth 110 share the same pitch circle 120, and have the same tooth depth (total tooth depth). On the other hand, the extended pinion teeth 110 have a larger tooth thickness than the reference pinion teeth 100. The tooth thickness is defined as the linear distance in the circumferential direction on the pitch circle 120 of the teeth. 12(a), the tooth thickness of the standard pinion tooth 100 is indicated by the symbol PS, and the tooth thickness of the expanded pinion tooth 110 is indicated by the symbol PW. The expanded pinion tooth 110 also has a larger thickness at the base than the reference pinion tooth 100.

[0025] 12(a) shows the rotation direction of the main shaft when the door opens (main shaft forward rotation direction 121) with an arrow. The main shaft forward rotation direction 121 is the side where the meshing between the pinion gear 14 and the rack 74 starts, and the direction opposite to the main shaft forward rotation direction 121 (main shaft reverse rotation direction) is the side where the meshing between the pinion gear 14 and the rack 74 ends.

[0026] A plurality of reference pinion teeth 100 are provided at regular intervals along the circumferential direction, and four reference pinion teeth are provided in this embodiment. All four reference pinion teeth 100 have the same shape. In this embodiment, a first reference pinion tooth 101, a second reference pinion tooth 102, a third reference pinion tooth 103, and a fourth reference pinion tooth 104 are provided as the reference pinion teeth 100 in this order from the meshing start side to the meshing end side. The first reference pinion tooth 101 to the fourth reference pinion tooth 104 are arranged at a standard pitch. The first reference pinion tooth 101 is located closest to the meshing start side among the four reference pinion teeth 100, and is located at the end of the meshing start side. The fourth reference pinion tooth 104 is located closest to the meshing end side among the four reference pinion teeth 100, and is located at the end of the meshing end side. A first reference pinion tooth groove 105 is provided between the first reference pinion tooth 101 and the second reference pinion tooth 102, a second reference pinion tooth groove 106 is provided between the second reference pinion tooth 102 and the third reference pinion tooth 103, and a third reference pinion tooth groove 107 is provided between the third reference pinion tooth 103 and the fourth reference pinion tooth 104.

[0027] The expanded pinion teeth 110 are spaced apart from the reference pinion teeth 100 on the meshing end side. In this embodiment, only one expanded pinion tooth 110 is provided. Therefore, the pinion gear 14 has a total of five teeth, including the reference pinion teeth 100 and the expanded pinion teeth 110. However, a plurality of expanded pinion teeth 110 may be arranged in parallel. The expanded pinion teeth 110 are spaced apart from the fourth reference pinion teeth 104 on the meshing end side. An expanded pinion tooth groove 111 is provided between the fourth reference pinion tooth 104 and the expanded pinion tooth 110. The expanded pinion tooth groove 111 has a circumferential length longer than the length from the first reference pinion tooth groove 105 to the third reference pinion tooth groove 107. The tooth flank of the expansion pinion teeth 110 on the meshing start side has a tooth profile, but the tooth flank of the expansion pinion teeth 110 on the meshing end side does not have a tooth profile.

[0028] A pinion small diameter portion 112 is provided on the meshing end side of the expanded pinion teeth 110. The pinion small diameter portion 112 has a smaller diameter than the expanded pinion teeth 110 and is smaller than the pitch circle 120. A pinion stopper surface 113 is provided on the meshing end side of the pinion small diameter portion 112. The pinion stopper surface 113 is an inclined surface that becomes larger in diameter toward the meshing end side.

[0029] The second shaft member 31 has an upper shaft portion extending upward from the pinion gear 14 and a lower shaft portion extending downward from the pinion gear 14. The outer peripheral surface of the upper shaft portion and the outer peripheral surface of the lower shaft portion are each formed with vertical serrations 32. As described above, in this embodiment, the vertical serrations 32 are hexagonal, and therefore the upper shaft portion and the lower shaft portion are hexagonal columns. The inner peripheral surface of the cam 13 is formed with vertical serrations, and the cams 13 are mounted on the upper shaft portion and the lower shaft portion so as not to rotate relative to each other. The lower end surface of the upper cam 13 and the upper end surface of the lower cam 13 abut against the upper end surface and the lower end surface of the pinion gear 14, respectively. The upper shaft portion is inserted into the joining hole of the first shaft member 30. The lower end surface of the first shaft member 30 abuts against the upper end surface of the upper cam 13. The vertical movement of the upper cam 13 is restricted by the lower end surface of the first shaft member 30 and the upper end surface of the pinion gear 14. A collar 33 is attached to the lower part of the lower shaft portion so as not to rotate relative to the first shaft member 30. The outer circumferential surface of the collar 33 is supported by the second bearing 26.

[0030] The cam 13 compresses the main coil spring 17 and the sub coil spring 18 during the door opening operation, and receives the elastic restoring force from the main coil spring 17 and the sub coil spring 18 during the door closing operation. The elastic restoring forces of the main coil spring 17 and the sub coil spring 18 are transmitted to the main shaft 11 via the cam 13 and become the closing force for closing the door. The cam 13 is a plate cam with its outer circumferential surface as a cam surface. During the door opening and closing operation, only a specified angular region of the entire circumference of the cam 13 is used.

[0031] A pair of upper and lower rollers 15 and a slider 16 are disposed on the right side of the cam 13. The rollers 15 and the slider 16 are positioned between the main coil spring 17 and the sub coil spring 18 and the cam 13. The rollers 15 are positioned on the left side of the slider 16, i.e., on the main shaft 11 side. The rollers 15 are disposed above and below in correspondence with the cam 13. The pair of upper and lower rollers 15 abut against the pair of upper and lower cams 13, respectively. The rollers 15 are rotatably supported by a support shaft 40. The support shaft 40 has an axis along the vertical direction. The support shaft 40 is parallel to the main shaft 11. The support shaft 40 is fixed to the left part of the slider 16. The rollers 15 and the slider 16 are connected via the support shaft 40 and move together in the left-right direction.

[0032] As shown in Fig. 5, the slider 16 has, in order from the spindle 11 side, a shaft mounting portion 41, a slider main portion 42, and a slider head portion 43. The shaft mounting portion 41, the slider main portion 42, and the slider head portion 43 respectively constitute the left, center, and right portions of the slider 16. The shaft mounting portion 41 extends leftward from the slider main portion 42. The shaft mounting portion 41 is plate-shaped with the thickness direction being in the vertical direction. A support shaft 40 is attached to the shaft mounting portion 41. The rollers 15 are arranged symmetrically above and below the shaft mounting portion 41. The upper and lower rollers 15 have the same diameter.

[0033] The slider main part 42 extends in the left-right direction. The slider main part 42 is cylindrical with an axis in the left-right direction. A long hole 44 is formed in the slider main part 42 along the left-right direction. The long hole 44 penetrates the slider main part 42 in the front-rear direction. In addition, the slider main part 42 has a flat surface 45 on the front and rear of the outer circumferential surface thereof, which is locally D-cut and extends in the up-down direction. The front and rear flat surfaces 45 are parallel to each other. By providing the flat surface 45 on the outer circumferential surface of the slider main part 42 in this manner, the hydraulic oil can move smoothly in the left-right direction. The long hole 44 opens into the front and rear flat surfaces 45.

[0034] The slider head portion 43 extends coaxially to the right from the slider main portion 42. The slider head portion 43 protrudes radially outward from the slider main portion 42. The slider head portion 43 is columnar or cylindrical, and has a larger diameter than the slider main portion 42. The outer peripheral surface of the slider head portion 43 is a guided surface 43a guided by the inner surface of the housing 10 (wall surface 20a of the accommodation chamber 20). When the slider 16 moves in the left-right direction, the guided surface 43a slides against the inner surface of the housing 10. Note that a part of the entire circumference of the outer peripheral surface of the slider head portion 43 may be locally cut out to allow hydraulic oil to pass through, and for example, a D-cut flat portion may be provided.

[0035] The slider head portion 43 may be formed integrally with the slider 16, but in this embodiment, it is configured as a separate member. That is, as shown in FIG. 5(b), the slider 16 includes a slider body 46 and a head sleeve 47 configured separately from the slider body 46. The head sleeve 47 forms the outer periphery of the slider head portion 43, and the outer periphery of the head sleeve 47 becomes the guided surface 43a. The head sleeve 47 is mounted on the slider body 46 so as to be movable in the left-right direction and non-rotatable. The slider body 46 has a shaft attachment portion 41 and a slider main portion 42, and is provided with a shaft portion 48. The shaft portion 48 is provided at the right end portion of the slider body 46. The shaft portion 48 has a smaller diameter than the slider main portion 42 and extends coaxially from the slider main portion 42 to the right. A step portion 50 is formed at the boundary between the slider main portion 42 and the shaft portion 48.

[0036] The head sleeve 47 is cylindrical and is mounted on the radially outer side of the shaft portion 48 so as to be slidable in the left-right direction. The head sleeve 47 has a mounting hole 47a penetrating in the left-right direction (axial direction of the head sleeve 47). A rotation prevention groove 47b is formed at a predetermined location on the entire circumference of the mounting hole 47a, which is recessed radially outward. Meanwhile, a rotation prevention protrusion 48a protruding radially outward is provided on the outer circumferential surface of the shaft portion 48. The rotation prevention protrusion 48a may be formed integrally with the shaft portion 48, but in this embodiment, it is formed by attaching a pin to the shaft portion 48 in the radial direction. The rotation prevention protrusion 48a is formed by the protrusion of the pin protruding from the outer circumferential surface of the shaft portion 48. The rotation prevention groove 47b and the rotation prevention protrusion 48a may be provided at one location, or may be provided at two or more locations. The rotation prevention protrusion 48a engages with the rotation prevention groove 47b, so that the head sleeve 47 cannot rotate relative to the shaft portion 48.

[0037] As shown in FIG. 5(a), the left end face 47c (the end face closer to the main shaft 11) of the head sleeve 47 abuts against the step portion 50 between the slider main portion 42 and the shaft portion 48, so that the head sleeve 47 cannot move any further to the left relative to the slider body 46, and the left-right position of the head sleeve 47 relative to the slider body 46 is determined. This state is the reference state of the head sleeve 47. The left end face 47c of the head sleeve 47 is shown in FIG. 5 as well as FIG. 2. FIG. 5(b) shows the state in which the head sleeve 47 has been removed from the slider body 46. The head sleeve 47 is not fixed to the slider body 46. Therefore, the head sleeve 47 can slide left and right relative to the slider body 46. The head sleeve 47 can slide rightward away from the slider main portion 42 from the state in which it is attached to the slider main portion 42 as shown in FIG. 5(a). 5(b), in this embodiment, the elongated hole 44 formed in the slider main portion 42 extends to the shaft portion 48. However, the elongated hole 44 does not have to extend to the shaft portion 48.

[0038] A main coil spring 17 and a sub coil spring 18 are disposed on the right side of the slider 16. The sub coil spring 18 is disposed coaxially inside the main coil spring 17. The main coil spring 17 and the sub coil spring 18 generate a closing force for closing the door. The main coil spring 17 and the sub coil spring 18 bias the slider 16, the roller 15, and the cam 13 to the left. The main coil spring 17 and the sub coil spring 18 are compression springs. The sub coil spring 18 has a smaller diameter and a weaker spring force than the main coil spring 17. The closing force for closing the door is the resultant force of the elastic restoring force of the main coil spring 17 and the elastic restoring force of the sub coil spring 18. The elastic restoring force of the main coil spring 17 is greater than the elastic restoring force of the sub coil spring 18. The left end of the main coil spring 17 abuts against a head sleeve 47 to urge the head sleeve 47 leftward, and the left end of the sub coil spring 18 abuts against a shaft portion 48 to urge the slider body 46 leftward.

[0039] The right end of the main coil spring 17 abuts against the spring retainer 60. The spring retainer 60 is located on the right side of the main coil spring 17. The spring retainer 60 is guided by the wall surface 20a of the accommodation chamber 20 and can move in the left-right direction. An adjustment shaft 61 penetrates the spring retainer 60 in the left-right direction. The adjustment shaft 61 has a male thread portion and is screwed into the female thread portion of the spring retainer 60. The spring retainer 60 can be moved in the left-right direction by rotating the adjustment shaft 61. When the spring retainer 60 moves to the left, the main coil spring 17 is compressed and the spring force becomes stronger. Conversely, when the spring retainer 60 moves to the right, the compression amount of the main coil spring 17 decreases and the spring force becomes weaker. A flange portion 61a for spring retaining is formed at the left end of the adjustment shaft 61. The right end of the sub coil spring 18 abuts against the flange portion 61a of the adjustment shaft 61.

[0040] The adjustment shaft 61 penetrates the right end cap 22. The adjustment shaft 61 is rotatably supported by the end cap 22. The right end of the adjustment shaft 61 protrudes outside the end cap 22, and a first adjustment gear 62 is attached to the right end. The first adjustment gear 62 meshes with a second adjustment gear 63. The second adjustment gear 63 is located below the mounting plate 2. An operation shaft 64 is rotatably supported by the mounting plate 2. The second adjustment gear 63 is attached to the lower end of the operation shaft 64. The second adjustment gear 63 can be rotated by rotating the operation shaft 64 from the upper side of the mounting plate 2. The adjustment shaft 61 can be rotated to move the spring holder 60 by rotating the first adjustment gear 62 via the second adjustment gear 63. In this embodiment, the spring holder 60, the adjustment shaft 61, the first adjustment gear 62, the second adjustment gear 63, and the operation shaft 64 constitute a spring force adjustment mechanism 19. Incidentally, the flange portion 61a of the adjustment shaft 61 does not move in the left-right direction even when the adjustment shaft 61 is rotated. Therefore, by rotating the adjustment shaft 61, the spring force of the main coil spring 17 can be adjusted, but the spring force of the sub coil spring 18 cannot be adjusted.

[0041] The accommodation chamber 20 accommodates a foam rubber 65. The foam rubber 65 is for absorbing expansion caused by a rise in temperature of the hydraulic oil. The foam rubber 65 is, for example, rod-shaped. The foam rubber 65 is, for example, disposed inside the sub coil spring 18.

[0042] The piston 12 buffers the door-closing operation. The piston 12 buffers the door-closing operation by forcing hydraulic oil into a flow control flow passage (not shown) during the door-closing operation. The piston 12 has a first head portion 70 at its left end. The first head portion 70 is located to the left of the main shaft 11. The first head portion 70 is cylindrical with its axis in the left-right direction. The outer peripheral surface of the first head portion 70 has approximately the same diameter as the wall surface 20a of the storage chamber 20. The outer peripheral surface of the first head portion 70 is guided by the wall surface 20a of the storage chamber 20. When the piston 12 moves, the outer peripheral surface of the first head portion 70 slides against the wall surface 20a of the storage chamber 20.

[0043] A through hole 71 is formed in the center of the first head portion 70 along the axial direction (left-right direction). A check valve is provided in this through hole 71. During the door-opening operation, the piston 12 moves to the right. During the door-opening operation, a ball 72, which is a valve body of the check valve, moves to the left to open the valve, and the hydraulic oil can pass through the through hole 71. On the other hand, during the door-closing operation, the piston 12 moves to the left. During the door-closing operation, the ball 72 of the check valve is pushed to the right by the hydraulic pressure of the hydraulic oil to close the through hole 71, and the hydraulic oil cannot pass through the through hole 71. During the door-closing operation, the hydraulic oil pushed to the left by the piston 12 is pushed into the flow control flow path, which is a bypass. The hydraulic oil passes through the flow control flow path and moves to a region to the right of the first head portion 70. In the flow control flow path, an adjustment valve (not shown) is arranged to control the flow rate of the hydraulic oil flowing through the flow control flow path. The adjustment valve can be adjusted from the upper side of the housing 10. By controlling the flow rate of the hydraulic oil flowing through the flow control flow path, the degree of cushioning during the door-closing operation can be adjusted. The first head portion 70 is provided with a safety valve 80 as a measure against damage when the door is forcibly closed by an external force.

[0044] FIG. 6 shows the piston 12 in a single state. The piston 12 has a pair of front and rear arms 73 on the right side of the first head portion 70. The pair of arms 73 are parallel to each other. The vertical dimensions of the front and rear arms 73 are equal to each other. The vertical dimension of the arm 73 is smaller than the diameter (outer diameter) of the first head portion 70 and smaller than the diameter of the second head portion 75 described later. The outer surface of the arm 73 is a curved surface that is arc-shaped in cross section. A part of the outer surface of the arm 73 slides against the wall surface 20a of the accommodation chamber 20. The arm 73 extends linearly along the left-right direction. The arm 73 extends beyond the main shaft 11 to the right. A rack 74 that constitutes a rack and pinion mechanism together with the pinion gear 14 is formed on the inner surface of one of the arms 73. The rack 74 meshes with the pinion gear 14. In this embodiment, as shown in Fig. 3 and Fig. 6(b), the pinion gear 14 and the rack 74 are disposed between a pair of upper and lower cams 13. Therefore, the vertical dimensions of the pinion gear 14 and the rack 74, i.e., the tooth width, are restricted by the pair of upper and lower cams 13. When the main shaft 11 rotates with the opening and closing of the door, the pinion gear 14 moves the piston 12 in the left and right directions. When the main shaft 11 rotates, the roller 15, the slider 16, and the piston 12 all move in the same direction. The movement amount of the piston 12 is larger than that of the roller 15 and the slider 16. The piston 12 moves significantly to the right relative to the roller 15 and the slider 16 during the door opening operation, and moves significantly to the left relative to the roller 15 and the slider 16 during the door closing operation.

[0045] The teeth of the rack 74 are shown in detail in FIG. 12(b). The teeth of the rack 74 correspond to the teeth of the pinion gear 14. The rack 74 has rack teeth arranged in parallel along the left-right direction, and the rack teeth include standard rack teeth 200 and extended rack teeth 210. The standard rack teeth 200 have a standard tooth shape, and the extended rack teeth 210 have a tooth shape different from the standard tooth shape. In FIG. 12(b), a pitch line 220 is shown by a dashed line. The standard rack teeth 200 and the extended rack teeth 210 share the pitch line 220 and have the same tooth depth (total tooth depth). On the other hand, the extended rack teeth 210 have a larger tooth thickness than the standard rack teeth 200. The tooth thickness is the dimension in the left-right direction on the pitch line 220 of the teeth. In FIG. 12(b), the tooth thickness of the standard rack teeth 200 is indicated by the symbol RS, and the tooth thickness of the extended rack teeth 210 is indicated by the symbol RW. The extended rack tooth 210 also has a greater thickness at the base than the standard rack tooth 200 .

[0046] 12(b), when the door is opened, the rack 74 moves to the right toward the main coil spring 17 and the sub coil spring 18. The right side is the side where the meshing between the pinion gear 14 and the rack 74 starts, and the left side, which is the direction away from the main coil spring 17 and the sub coil spring 18, is the side where the meshing between the pinion gear 14 and the rack 74 ends.

[0047] A plurality of reference rack teeth 200 are provided at regular intervals along the left-right direction, and three are provided in this embodiment. All three reference rack teeth 200 have the same shape. In this embodiment, a first reference rack tooth 201, a second reference rack tooth 202, and a third reference rack tooth 203 are provided as the reference rack teeth 200 in this order from the meshing start side to the meshing end side. The first reference rack tooth 201 to the third reference rack tooth 203 are arranged at a standard pitch. The first reference rack tooth 201 is located closest to the meshing start side among the three reference rack teeth 200, and is located at the end of the meshing start side. In addition, the first reference rack tooth 201 is located closest to the meshing start side among all the rack teeth. The third reference rack tooth 203 is located closest to the meshing end side among the three reference rack teeth 200, and is located at the end of the meshing end side.

[0048] A base surface 204 is provided on the right side (meshing start side) of the first reference rack tooth 201. The first reference rack tooth 201 protrudes in the front-rear direction relative to the base surface 204. A first reference rack tooth groove 205 is provided between the first reference rack tooth 201 and the second reference rack tooth 202, a second reference rack tooth groove 206 is provided between the second reference rack tooth 202 and the third reference rack tooth 203, and a third reference rack tooth groove 207 is provided between the third reference pinion tooth 103 and the expansion rack tooth 210. The first reference rack tooth groove 205, the second reference rack tooth groove 206, and the third reference rack tooth groove 207 have the same shape, and the bottom surface of each tooth groove is located on the same plane as the base surface 204.

[0049] The extension rack tooth 210 is provided at a distance from the reference rack tooth 200 on the meshing end side. In this embodiment, only one extension rack tooth 210 is provided. Therefore, the rack 74 has a total of four teeth, including the reference rack tooth 200 and the extension rack tooth 210. However, a plurality of extension rack teeth 210 may be provided in parallel. The extension rack tooth 210 is provided at a distance from the third reference rack tooth 203 on the meshing end side. An extension rack tooth groove 211 is provided on the meshing end side of the extension rack tooth 210. The extension rack tooth groove 211 has a longer length in the left-right direction than the length from the first reference rack tooth groove 205 to the third reference rack tooth groove 207. The bottom surface of the extension rack tooth groove 211 is located on the same plane as the bottom surfaces of the first reference rack tooth groove 205, the second reference rack tooth groove 206, and the third reference rack tooth groove 207.

[0050] A rack stopper surface 213 is provided on the meshing end side of the extended rack tooth groove 211. The rack stopper surface 213 is a flat surface along the left-right direction. The rack stopper surface 213 protrudes in the front-rear direction beyond the bottom surface of the extended rack tooth groove 211. The rack stopper surface 213 is located on the same plane as the tooth tip surface of the reference rack tooth 200 and the tooth tip surface of the extended rack tooth 210.

[0051] 13 and 14 , the second reference pinion tooth 102 engages with the first reference rack tooth groove 205, the third reference pinion tooth 103 engages with the second reference rack tooth groove 206, the third reference pinion tooth 103 engages with the third reference rack tooth groove 207, and the extended pinion tooth 110 engages with the extended rack tooth groove 211. The right tooth flank of the first reference rack tooth 201 meshes with the first reference pinion tooth 101, and the left tooth flank of the first reference rack tooth 201 meshes with the second reference pinion tooth 102. The right tooth flank of the second reference rack tooth 202 meshes with the second reference pinion tooth 102, and the left tooth flank of the second reference rack tooth 202 meshes with the third reference pinion tooth 103. The right tooth flank of the third reference rack tooth 203 meshes with the third reference pinion tooth 103, and the left tooth flank of the third reference rack tooth 203 meshes with the fourth reference pinion tooth 104. The right tooth flank of the extended rack tooth 210 meshes with the fourth reference pinion tooth 104, and the left tooth flank of the extended rack tooth 210 meshes with the extended pinion tooth 110. The extended pinion tooth 110 is the last tooth that meshes with the rack 74 when the door is opened, and the extended rack tooth 210 is the last tooth that meshes with the pinion gear 14 when the door is opened.

[0052] 14(b), the pinion stopper surface 113 abuts against the rack stopper surface 213. When the pinion stopper surface 113 abuts against the rack stopper surface 213, the pinion gear 14 cannot rotate any further in the main shaft forward rotation direction 121, and therefore the main shaft 11 cannot rotate any further in the main shaft forward rotation direction 121, and the door cannot open any further. When the pinion stopper surface 113 abuts against the rack stopper surface 213, the extended pinion teeth 110 mesh with the extended rack teeth 210. The pinion stopper surface 113 and the rack stopper surface 213 form a stop device that stops the door at a predetermined door-opening angle.

[0053] The piston 12 has a second head portion 75 at its right end. The arm portion 73 extends to the second head portion 75. The arm portion 73 connects the first head portion 70 and the second head portion 75. The second head portion 75 is cylindrical. The second head portion 75 has a center line along the left-right direction. The outer peripheral surface of the second head portion 75 is supported by the wall surface 20a of the accommodation chamber 20, and when the piston 12 moves, the outer peripheral surface of the second head portion 75 slides on the wall surface 20a of the accommodation chamber 20.

[0054] The roller 15 and the slider 16 are fitted inside the piston 12. The roller 15 is located to the left of the second head portion 75 of the piston 12. The slider main portion 42 of the slider 16 is located inside the second head portion 75. The inner peripheral surface of the second head portion 75 has a larger diameter than the outer peripheral surface of the slider main portion 42, and a predetermined gap is provided between the inner peripheral surface of the second head portion 75 and the outer peripheral surface of the slider main portion 42. Therefore, the outer peripheral surface of the slider main portion 42 does not contact the inner peripheral surface of the second head portion 75.

[0055] The inner surface of the right part of the pair of arms 73 is formed with an arc-shaped surface 76 having the same diameter as the inner peripheral surface of the second head part 75. The arc-shaped surface 76 is continuous with the inner peripheral surface of the second head part 75. In addition, roller guide surfaces 77 are provided above and below the arc-shaped surface 76. As shown in FIG. 4, the roller guide surface 77 guides the roller 15. A pair of roller guide surfaces 77 are provided, one above and one below, corresponding to the pair of upper and lower rollers 15. The upper roller guide surface 77 is located above the rack 74, and the lower roller guide surface 77 is located below the rack 74. The roller guide surface 77 extends along the left-right direction. The roller guide surface 77 is a plane whose normal direction is the front-rear direction. In this embodiment, the roller guide surfaces 77 are provided on the pair of front and rear arms 73, respectively, and the pair of front and rear roller guide surfaces 77 are provided symmetrically to each other. By providing a pair of roller guide surfaces 77 in this way, the door closer can be easily applied to both right-hand and left-hand doors. However, the roller guide surface 77 may be provided only on the front side or only on the rear side depending on whether the machine is right-handed or left-handed.

[0056] The second head portion 75 has a horizontal hole 78 penetrating in the front-rear direction, and a support pin 79 is inserted into the horizontal hole 78. The support pin 79 is inserted into the long hole 44 of the slider main portion 42 in the front-rear direction. The support pin 79 prevents the slider 16 from rotating relative to the piston 12 and moving up and down. When the piston 12 moves relative to the slider 16, the support pin 79 moves left and right through the long hole 44 of the slider 16. When the door-opening angle is 0 degrees, that is, in the closed door state, as shown in FIG. 2, the right end surface 75a of the second head portion 75 (the end surface of the piston 12 facing the head sleeve 47) is separated to the left from the left end surface 47c of the head sleeve 47, and a predetermined interval is provided between the right end surface 75a of the second head portion 75 and the left end surface 47c of the head sleeve 47.

[0057] Figures 7 to 10 show the state of the door closer when the door is opening. Figure 7 shows the state when the door is open to 57 degrees. In this state, the main shaft 11 has rotated 90 degrees from the fully closed state. Figure 8 shows the state when the door is opened to 70 degrees, Figure 9 shows the state when the door is opened to 80 degrees, and Figure 10 shows the state when the door is opened to 125 degrees. The maximum door opening angle of the door closer in this embodiment is 125 degrees. Therefore, Figure 10 shows the state at the maximum door opening angle.

[0058] When the door is opened from the fully closed state as shown in FIG. 1 and FIG. 2, the cam 13 rotates left (counterclockwise) together with the main shaft 11 in a plan view, and the roller 15 and the slider 16 are pushed by the cam 13 and start to move to the right. The roller 15 is supported by the roller guide surface 77. Therefore, the roller 15 moves to the right while being guided by the roller guide surface 77. The piston 12 also moves to the right due to the rotation of the main shaft 11. The amount of movement of the piston 12 to the right is greater than the amount of movement of the roller 15 to the right. Therefore, the roller guide surface 77 of the piston 12 moves to the right relative to the roller 15. The slider 16 moves to the right while the guided surface 43a is guided by the inner surface of the housing 10 (the wall surface 20a of the accommodation chamber 20). The inner surface of the housing 10 is the slider guide surface that guides the guided surface 43a.

[0059] The roller 15 and the slider 16 move to the right together, but the guided surface 43a of the roller 15 and the slider 16 are separated in the left-right direction, and the slider 16 is separated inward from the wall surface 20a of the accommodation chamber 20 between the roller 15 and the guided surface 43a in the left-right direction. Therefore, the roller 15 and the slider 16 are guided at two points separated in the left-right direction, and can move smoothly in the left-right direction. In particular, the roller 15 is located at the left end of the slider 16, and the guided surface 43a is located at the right end of the slider 16, so that the left-right separation distance between the roller 15 and the guided surface 43a can be easily secured, and the roller 15 and the slider 16 can move smoothly in the left-right direction.

[0060] In addition, since the outer peripheral surface of the roller 15 is not in a free state but is guided by the roller guide surface 77, the roller 15 moves smoothly in the left-right direction, and as a result, the roller 15 and the slider 16 can move smoothly in the left-right direction. Furthermore, since the outer peripheral surface of the roller 15 is guided by the roller guide surface 77, there is no need to extend the slider 16 to a position in front of or behind the roller 15 to provide the guided surface 43a of the slider 16 in a position in front of or behind the roller 15. Therefore, the dimension in the front-back direction of the door closer main body 1 can be reduced, and more room is created in the dimension in the front-back direction, increasing the freedom of design.

[0061] In FIG. 11, the force acting from the cam 13 to the roller 15 is indicated by an arrow F. FIG. 11 shows a state where the door opening angle is 5 degrees. In the closing state, a large force acts from the cam 13 to the roller 15. In FIG. 11, the point of action of the force acting from the cam 13 to the roller 15 is indicated by the symbol 13a. The force F acting from the cam 13 to the roller 15 is inclined in the front-rear direction with respect to the left-right direction in a plan view, and in this embodiment, it is inclined backward with respect to the left-right direction. As shown in the schematic diagram of FIG. 11(b), the straight line connecting the center 11a (rotation center) of the support shaft 11 and the center 15a (rotation center) of the roller 15 is the above-mentioned center line CL, but when the action point 13a is located forward with respect to this center line CL, the force F is inclined backward with respect to the left-right direction, and conversely, when the action point 13a is located backward, the force F is inclined forward with respect to the left-right direction. In this embodiment, since the action point 13a is located forward with respect to the center line CL, the force F is inclined backward with respect to the left-right direction.

[0062] This force F is resolved into the left-right direction and the front-rear direction. The force F is resolved into a left-right component force F1 and a front-rear component force F2. The left-right component force F1 moves the roller 15 and the slider 16 to the right. On the other hand, the front-rear component force F2 faces the rear and tries to move the roller 15 rearward. However, since the roller guide surface 77 is provided on the rear side of the roller 15, the outer circumferential surface of the roller 15 is supported by the rear roller guide surface 77. Therefore, the roller 15 can move smoothly in the left-right direction, and the roller 15 and the slider 16 can move smoothly in the left-right direction as one body. In this embodiment, the roller guide surface 77 is also provided on the front side, but the front roller guide surface 77 may be omitted. However, if the roller guide surface 77 is provided on both the front and rear sides, the door closer can be applied to both left-handed and right-handed doors, and versatility is increased.

[0063] 7 to 10, when the door is opened and the slider 16 moves to the right, the main coil spring 17 and the sub coil spring 18 are pushed by the slider 16 and compressed. Meanwhile, the piston 12 is also moved to the right, which is the same direction as the roller 15 and the slider 16, by the pinion gear 14 and the rack 74.

[0064] The amount of movement of the piston 12 relative to the rotation angle of the main shaft 11 is larger than the amount of movement of the slider 16 relative to the rotation angle of the main shaft 11. The piston 12, the roller 15, and the slider 16 move in the same direction, but the movement speed of the piston 12 is generally faster than the movement speed of the slider 16. Therefore, the piston 12 moves relatively farther to the right than the roller 15 and the slider 16, and the second head portion 75 of the piston 12 moves relatively to the right of the slider main portion 42 and approaches the head sleeve 47.

[0065] 9, when the door is opened to 80 degrees, the right end surface 75a of the second head portion 75 of the piston 12 abuts against the left end surface 47c of the head sleeve 47. At that time, the support pin 49, which is moving relatively to the right in the elongated hole 44, does not reach the right end of the elongated hole 44. Even at an opening angle of 80 degrees, the roller 15 is guided by the roller guide surface 77. Note that the opening angle when the second head portion 75 abuts against the left end surface 47c of the head sleeve 47 is not limited to 80 degrees and may be any angle.

[0066] As the door opens further, the second head portion 75 of the piston 12 pushes the head sleeve 47 to the right, moving the head sleeve 47 away from the slider body 46 to the right. The head sleeve 47 moves to the right together with the second head portion 75 of the piston 12, and moves to the right relative to the shaft portion 48 of the slider body 46. The left end face 47c of the head sleeve 47 moves away from the step portion 50 of the slider body 46. As the head sleeve 47 moves to the right, the head sleeve 47 can continue to push the main coil spring 17 to the right, and the main coil spring 17 is further compressed. Therefore, in the section where the door-opening angle is between 80 degrees and 125 degrees, the main coil spring 17 is compressed by a larger amount than the sub coil spring 18. During the door closing operation in the door opening angle range of 80 degrees to 125 degrees, the elastic restoring force of the main coil spring 17 is transmitted from the head sleeve 47 to the piston 12, and further transmitted to the main shaft 14 via the pinion gear 14 meshing with the rack 74 of the piston 12, to become the closing force for closing the door. Note that in this range, the slider 16 may not move to the right and the increase in the compression amount of the sub coil spring 18 may be zero.

[0067] Also, in the section where the door opening angle is between 80 degrees and 125 degrees, the roller 15 moves away from the roller guide surface 77 to the left. That is, in this embodiment, the roller 15 is guided by the roller guide surface 77 in the section where the door opening angle is between 0 degrees and 80 degrees, and is not guided by the roller guide surface 77 in the section where the door opening angle is between 80 degrees and 125 degrees. In the section where the door opening angle is between 80 degrees and 125 degrees, the roller 15 does not move in the left-right direction, or the amount of movement in the left-right direction is small. Therefore, the roller guide surface 77 can be omitted in the section where the door opening angle is between 80 degrees and 125 degrees, and the length of the roller guide surface 77 in the left-right direction can be shortened. In particular, if the roller guide surface 77 is configured to move away from the roller 15 in the left-right direction without guiding the roller 15 at the maximum door opening angle (125 degrees in this embodiment), it is effective to shorten the dimension of the roller guide surface 77 in the left-right direction. In this way, the roller guide surface 77 does not need to guide the roller 15 within the full door-open angle range, and the roller guide surface 77 guides the roller 15 at least at the time of closing (when the door-open angle is between 0 degrees and 5 degrees), thereby effectively ensuring smooth movement of the roller 15 and slider 16 in the left-right direction.

[0068] Next, the meshing between the pinion gear 14 and the rack 74 when the door is opening will be described in detail. Figures 13 and 14 show the change in the meshing state between the pinion gear 14 and the rack 74 when the door is opening. Figure 13(a) shows a state where the door opening angle is 0 degrees (fully closed state), and corresponds to Figures 1 and 2. In the fully closed state, the center line in the front-rear direction passing through the center of the main shaft 11 passes through the center in the left-right direction of the first reference rack tooth 201 and passes through the center in the left-right direction of the first reference pinion tooth groove 105. In the fully closed state, the first reference rack tooth 201 is located on the center line in the front-rear direction of the main shaft 11. Figure 13(b) shows a state where the main shaft 11 is rotated 90 degrees from the fully closed state, and the door opening angle is 57 degrees, and corresponds to Figure 7. In this state, the extension pinion tooth 110 does not mesh with the extension rack tooth 210.

[0069] FIG. 13(c) shows the state where the door opening angle is 70 degrees, and corresponds to FIG. 8. When the door opening angle becomes 70 degrees, the expansion pinion teeth 110 start to mesh with the expansion rack teeth 210. In other words, in the range where the door opening angle is from 0 degrees to less than 70 degrees, the expansion pinion teeth 110 and the expansion rack teeth 210 do not mesh, and the reference pinion teeth 100, which are standard teeth, and the reference rack teeth 200 are in mesh. The door opening angle when the expansion pinion teeth 110 start to mesh with the expansion rack teeth 210 is called the expansion start angle. In this embodiment, the expansion start angle is 70 degrees. At the expansion start angle, the second head portion 75 of the piston 12 does not reach the head sleeve 47, and the right end surface 75a of the second head portion 75 of the piston 12 is separated to the left from the left end surface 47c of the head sleeve 47.

[0070] FIG. 14(a) shows the state where the door-opening angle is 80 degrees, and corresponds to FIG. 9. As described above, when the door-opening angle becomes 80 degrees, the second head portion 75 of the piston 12 reaches the head sleeve 47, and the right end surface 75a of the second head portion 75 of the piston 12 abuts against the left end surface 47c of the head sleeve 47. That is, when the door-opening angle becomes 80 degrees, the piston 12 starts compressing the main coil spring 17, and the closing force of the main coil spring 17 and the sub coil spring 18 acting on the pinion gear 14 and the rack 74 increases in a step-like manner. The door-opening angle at this time is called the step angle. In this embodiment, the step angle is 80 degrees, which is larger than the above-mentioned expansion start angle. That is, the expansion pinion teeth 110 and the expansion rack teeth 210 are already engaged at the step angle.

[0071] FIG. 14(b) shows the state where the door-opening angle is 125 degrees, which corresponds to FIG. 10 and is the maximum door-opening angle. When the door-opening angle reaches 125 degrees, the pinion stopper surface 113 comes into contact with the rack stopper surface 213. Therefore, the pinion gear 14 cannot rotate any further, and further rotation of the main shaft 11 is prevented, preventing further opening of the door. Note that even at the maximum door-opening angle, the expansion pinion teeth 110 mesh with the expansion rack teeth 210. That is, the expansion pinion teeth 110 and the expansion rack teeth 210 continue to mesh with each other in the section from the expansion start angle to the maximum door-opening angle.

[0072] As described above, in the door closer of this embodiment, when the door opens from the fully closed state to the maximum door opening angle, the reference pinion teeth 100 and the reference rack teeth 200, which have a standard tooth thickness, mesh with each other in the first half of the door opening operation, and the extended pinion teeth 110 and the extended rack teeth 210, which have a larger tooth thickness, mesh with each other in the second half. In the second half of the door opening operation, a larger force acts on the pinion gear 14 and the rack 74 compared to the first half. Under such circumstances, the extended pinion teeth 110 and the extended rack teeth 210 mesh with each other, so that damage to the teeth of the pinion gear 14 and the rack 74 is prevented. In addition, the strength of the teeth can be improved without increasing the tooth width of the pinion gear 14 and the rack 74, and the increase in the vertical dimension of the door closer can be prevented.

[0073] In particular, both the expansion pinion teeth 110 and the expansion rack teeth 210 are the final teeth. Therefore, damage to the teeth, which is particularly likely to occur in the final teeth, can be effectively prevented. In addition, the expansion pinion teeth 110 and the expansion rack teeth 210 mesh with each other at the maximum door-opening angle. Therefore, damage to the teeth, which is likely to occur at the maximum door-opening angle, can be effectively prevented.

[0074] Furthermore, in this embodiment, the piston 12 reaches the head sleeve 47 at the step angle, but because the expansion pinion teeth 110 and the expansion rack teeth 210 mesh with each other at the step angle, damage to the teeth that is likely to occur at the step angle can be prevented. If the door is opened forcefully, the piston 12 may collide with the head sleeve 47 with force at the step angle, and an impact load may act on the teeth of the pinion gear 14 and the rack 74. Because the expansion pinion teeth 110 and the expansion rack teeth 210 mesh with each other at the step angle, damage to the teeth due to impact can be effectively prevented.

[0075] Moreover, since the expansion start angle is smaller than the step angle, the expansion pinion teeth 110 and the expansion rack teeth 210 can mesh in a stable state at the step angle. Therefore, damage to the teeth at the step angle can be prevented more reliably. The expansion pinion teeth 110 and the expansion rack teeth 210 continue to mesh up to the maximum door-opening angle. Therefore, damage to the teeth can be reliably prevented from the expansion start angle to the maximum door-opening angle.

[0076] On the other hand, since the pitch circle 120 of the extended pinion teeth 110 is the same as the pitch circle 120 of the reference pinion teeth 100, and the pitch line 220 of the extended rack teeth 210 is the same as the pitch line 220 of the reference rack teeth 200, there is no need to excessively increase the dimensions of the pinion gear 14 and the rack 74. This makes it possible to suppress an increase in the dimensions of the door closer main body 1. Furthermore, since there is no need to change the pitch circle 120 and the pitch line 220, the pinion gear 14 and the rack 74 are also easy to manufacture.

[0077] In this embodiment, a pair of cams 13 are provided, one above the other, but there may be only one cam 13. In that case, the roller 15 may also be one, not a pair above and below. Also, a concealed type door closer has been exemplified, but it may be configured to be attached to the outer surface of the door. The door closer may not be of the sliding type, but may be one equipped with a link mechanism. Furthermore, while the main coil spring 17 and the sub-coil spring 18 are provided as springs that generate a closing force, for example, the sub-coil spring 18 may be omitted.

[0078] In the above embodiment, the pinion stopper surface 113 and the rack stopper surface 213 are provided, which constitute a stop device that stops the door at a predetermined door-opening angle. That is, in the above embodiment, the stop device is provided inside the door closer main body 1, but the stop device may be provided outside the door closer main body 1. Also, the stop device may be provided both inside and outside the door closer main body 1. In a configuration that includes a stop device, it is preferable that the extended pinion teeth 110 and the extended rack teeth 210 are engaged when the door is stopped at a predetermined door-opening angle by the stop device.

[0079] In particular, when the door is opened forcefully, an impact load may act on the pinion gear 14 and the teeth of the rack 74 at the door opening angle at which the stop device operates. Therefore, if the extended pinion teeth 110 and the extended rack teeth 210 are engaged at the door opening angle at which the stop device operates, damage to the teeth can be effectively prevented. However, a configuration without a stop device may also be used, and a configuration without the pinion stopper surface 113 and the rack stopper surface 213 provided inside the door closer main body 1 may also be used.

[0080] For example, even if the door closer is configured to accommodate a door opening angle of 180 degrees, i.e., the main shaft is configured to be able to rotate up to an opening angle of 180 degrees, when the door closer is attached to the door or door frame and in use the maximum door opening angle is less than 180 degrees, for example when the door cannot be opened beyond 100 degrees, it is preferable that the extension pinion teeth 110 and the extension rack teeth 210 mesh at the maximum door opening angle of 100 degrees.

[0081] Also, the cam 13 may not be provided. FIG. 15 shows an example, but in this embodiment, the cam 13 is not provided, and only a rack and pinion mechanism is provided. The piston 12 pushes the main coil spring 17 and the sub coil spring 18 over the entire range to compress them. The pinion gear 14 and the rack 74 are configured in the same manner as described above. FIG. 15(a) shows the state where the door opening angle is 0 degrees, i.e., the fully closed state, and FIG. 15(b) shows the state where the door opening angle is at the maximum. At the maximum door opening angle, the extended pinion teeth 110 mesh with the extended rack teeth 210. Also, in this embodiment, the pinion stopper surface 113 and the rack stopper surface 213 are provided, and at the maximum door opening angle, the pinion stopper surface 113 abuts against the rack stopper surface 213 to prevent further rotation of the main shaft 11.

[0082] For example, in the configuration shown in Fig. 15, in the fully closed state, the piston 12 may abut only against the main coil spring 17, but not against the sub-coil spring 18, and when the door is opened to a certain extent, the piston 12 may abut against the sub-coil spring 18 and start compressing it. In this case, the door-opening angle when the piston 12 abuts against the sub-coil spring 18 is the step angle. It is preferable that the expansion pinion teeth 110 and the expansion rack teeth 210 mesh with each other at that step angle. Also, when the door is opened, the reference pinion teeth 100 and the reference rack teeth 200 may mesh with each other in the section until the piston 12 abuts against the sub-coil spring 18, and the expansion pinion teeth 110 and the expansion rack teeth 210 may mesh with each other in the section after the piston 12 abuts against the sub-coil spring 18. [Explanation of symbols]

[0083] 1 Door closer body 2 Mounting plate 3 Arm 10. Housing 11 Spindle 11a center 12 Piston 13. Cam 13a Point of action 14 Pinion gear 15 Coro 15a center 16 Slider 17 Main coil spring 18 Sub coil spring 19 Spring force adjustment mechanism 20 Containment Room 20a Wall 21 Left end cap 22 Right end cap 23 First bearing holder 24 Second bearing holder 25 First bearing 26 Second bearing 30 First shaft member 31 Second shaft member 32 Vertical serration 33 Color 40 Spindle 41 Shaft mounting part 42 Slider main part 43 Slider head part 43a Guided surface 44 Long hole 45 Plane section 46 Slider body 47 Head Sleeve 47a Mounting hole 47b Anti-rotation groove 47c Left end surface 48 Shaft 48a Anti-rotation protrusion 50 Step 60 Spring holder 61 Adjustment axis 61a Flange part 62 First Adjustment Gear 63 Second Adjustment Gear 64 Operation axis 65 Foam rubber 70 First head section 71 Through hole 72 Ball 73 Arm 74 Rack 75 Second head part 75a right end surface (right end surface of piston 12) 76 Arc-shaped surface 77 Roller guideway 78 Horizontal hole 79 Support pin 80 Safety valve 90 Guide member 91 Second Colo 100 Reference pinion teeth 101 First reference pinion tooth 102 Second reference pinion tooth 103 Third reference pinion tooth 104 Fourth reference pinion tooth 105 First reference pinion tooth space 106 Second reference pinion tooth space 107 Third reference pinion tooth space 110 Extended pinion teeth 111 Expanded pinion tooth space 112 Pinion small diameter section 113 Pinion stopper surface 120 Pitch Circle 121 Spindle forward rotation direction 200 Reference rack teeth 201 First reference rack tooth 202 Second reference rack tooth 203 Third reference rack tooth 204 Base surface 205 First reference rack tooth space 206 Second reference rack tooth space 207 Third reference rack tooth space 210 Extended rack teeth 211 Extended rack tooth space 213 Rack stopper surface 220 Pitch line CL center line X First orthogonal direction Y Second orthogonal direction PS Standard pinion tooth thickness PW Extended pinion tooth thickness RS Standard rack tooth thickness RW Extended rack tooth thickness

Claims

1. A main shaft that rotates in conjunction with the opening and closing of the door, A spring that stores energy when the door is opened and applies a closing force to the main shaft when the door is closed; A pinion gear that rotates together with the main shaft; a piston having a rack that meshes with the pinion gear and that moves with the rotation of the main shaft to store energy in the spring when the door is opened and to transmit the closing force of the spring to the main shaft when the door is closed; The pinion gear has reference pinion teeth and extended pinion teeth having the same pitch circle as the reference pinion teeth and a larger tooth thickness than the reference pinion teeth, The rack has a reference rack tooth and an extended rack tooth having the same pitch line as the reference rack tooth and a larger tooth thickness than the reference rack tooth, A door closer in which the reference pinion teeth and the reference rack teeth mesh with each other at a relatively small door opening angle, and the extended pinion teeth and the extended rack teeth mesh with each other at a relatively large door opening angle.

2. 2. The door closer according to claim 1, wherein at a maximum door opening angle, the reference pinion teeth and the reference rack teeth do not mesh, and the extended pinion teeth and the extended rack teeth mesh.

3. 2. The door closer according to claim 1, wherein the expanding pinion teeth and the expanding rack teeth mesh with each other at a step angle, which is a door-opening angle at which the force acting on the pinion gear and the rack increases stepwise during the door opening process.

4. 4. The door closer of claim 3, wherein the expanding pinion teeth and the expanding rack teeth begin to mesh at an expanding start angle that is a door opening angle that is less than the step angle.

5. 5. The door closer of claim 4, wherein the expanding pinion teeth and the expanding rack teeth continue to mesh from the expanding start angle to the maximum door opening angle.

Images