Cam motion matching structure and door closer

Abstract

The utility model discloses a cam motion matching structure and discloses a door closer with the cam motion matching structure, the cam motion matching structure comprises a shell, a plunger, a reset spring, a transmission shaft and a cam part, and the plunger is arranged in the shell in a sliding mode; one end of the reset spring abuts against the shell, and the other end of the reset spring abuts against the plunger. The transmission shaft is rotationally connected with the shell; the cam part is arranged on the transmission shaft; the cam part comprises a first cam layer and a second cam layer, the first cam layer is provided with a first roller pin, the plunger is provided with a second roller pin, when the transmission shaft rotates within a first angle range, the first roller pin and the plunger roll in an abutting mode, and when the transmission shaft rotates within a second angle range, the second roller pin and the second cam layer roll in an abutting mode. According to the cam motion matching structure, the friction resistance between the cam and the plunger can be reduced, the abrasion between the cam and the plunger is reduced, the cam and the plunger are not prone to being damaged, and the service life is guaranteed.

Description

Technical Field

[0001] This utility model relates to the technical field of door closer structure, and in particular to a cam motion coordination structure and a door closer. Background Technology

[0002] A door closer is a hydraulic device similar to a spring on the door frame. When the door is opened, it can be compressed and then released to automatically close the door, just like a spring door. It can ensure that the door is accurately and promptly closed to the initial position after being opened.

[0003] Structurally, the door closer includes a housing, a drive shaft rotatably connected to the housing, a cam mounted on the drive shaft, a plunger slidably disposed within the housing, and a return spring supporting the plunger's reset. One of the drive shaft and the housing is mounted on the door leaf, and the other of the drive shaft and the housing is mounted on the door frame or the ground. When the door is opened, the drive shaft rotates relative to the housing, causing the cam on the drive shaft to rotate synchronously to push the plunger to compress the return spring. After the door is opened, the elastic potential energy stored in the return spring is released due to the compression, pushing the plunger in the opposite direction to reset it, thereby driving the cam to rotate and reset, thus closing the door.

[0004] However, in existing door closers, the frictional resistance between the cam and the plunger is high, which easily leads to excessive wear and tear on the cam and plunger, making them prone to damage and affecting their service life. Utility Model Content

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a cam motion engagement structure that can reduce the frictional resistance between the cam and the plunger, reduce wear on both the cam and the plunger, making them less prone to damage and ensuring their service life.

[0006] This utility model also proposes a door closer having the above-mentioned cam motion coordination structure.

[0007] A cam motion coordination structure according to a first aspect embodiment of the present invention includes:

[0008] case;

[0009] The plunger is slidably disposed within the housing;

[0010] The return spring has one end abutting against the housing and the other end abutting against the plunger;

[0011] The drive shaft is rotatably connected to the housing;

[0012] A cam portion, disposed on the drive shaft, is used to drive the plunger to compress the return spring;

[0013] The cam portion includes a first cam layer and a second cam layer arranged along the axial direction of the drive shaft. The first cam layer is provided with a first needle roller, and the plunger is provided with a second needle roller. When the drive shaft rotates within a first angle range, the first needle roller abuts against the plunger and rolls. When the drive shaft rotates within a second angle range, the second needle roller abuts against the second cam layer and rolls.

[0014] According to a cam motion coordination structure of an embodiment of the present invention, at least the following beneficial effects are achieved:

[0015] 1. This utility model comprises a housing, a plunger, a return spring, a drive shaft, and a cam. The plunger is slidably disposed within the housing. One end of the return spring abuts against the housing, and the other end of the return spring abuts against the plunger. The drive shaft is rotatably connected to the housing, and the cam is disposed on the drive shaft. It can be understood that when the door is opened, the drive shaft rotates relative to the housing, causing the cam to rotate. During the rotation of the cam, the cam can drive the plunger to slide within the housing along its own circumferential trajectory, allowing the plunger to compress the spring. When the door is closed, the door loses its pushing force, and the elastic potential energy accumulated in the compressed spring is released, pushing the plunger back to its original position. This, in turn, causes the cam to rotate back to its original position, closing the door and thus achieving the effect of automatic door closing.

[0016] 2. This utility model includes a first cam layer and a second cam layer arranged axially along the transmission shaft in the cam part. The first cam layer is provided with a first needle roller, and the plunger is provided with a second needle roller. When the transmission shaft rotates within a first angle range, the first needle roller rolls against the plunger. When the transmission shaft rotates within a second angle range, the second needle roller rolls against the second cam layer. It can be understood that when the door swings, the rolling of the first needle roller against the plunger and the rolling of the second needle roller against the second cam layer avoid the sliding friction between the cam part and the plunger, reduce the frictional resistance between the cam part and the plunger, reduce the wear of the cam part and the plunger, and make the cam part and the plunger less prone to damage, thus ensuring service life.

[0017] 3. By setting a first needle roller and a second needle roller, the diameters of the first needle roller and the second needle roller are small, which can reduce the space occupied by the first needle roller and the second needle roller in the door closer, making the door closer smaller in size.

[0018] 4. By setting a first needle roller and a second needle roller, the first needle roller and the second needle roller respectively serve as support components between the cam part and the plunger in the first angle range and the second angle range of the transmission shaft. This avoids the reduction of the life of the support component due to long-term use of a single support component, thereby helping to extend the service life of the door closer.

[0019] According to some embodiments of the present invention, the plunger is provided with a first positioning groove, which cooperates with the first needle roller to position the drive shaft in a closed state.

[0020] The advantage of this invention is that by providing a first positioning groove on the plunger, and having the first positioning groove cooperate with the first needle roller to position the drive shaft in the closed state, the position of the door leaf in the closed state is more stable, thus preventing the door leaf from shaking.

[0021] According to some embodiments of the present invention, the first cam layer is provided with a second positioning groove, and the second positioning groove cooperates with the second needle roller to position the transmission shaft in the open state.

[0022] The advantages of this invention are: by providing a second positioning groove in the first cam layer, the second positioning groove cooperates with the second needle roller to position the drive shaft in the open state, thereby enabling the door leaf to be positioned after opening, and the door leaf can be maintained in the open state through the cooperation of the second positioning groove and the second needle roller, eliminating the need to use external force to keep the door leaf in the open state, thus making it convenient to use. In addition, when it is necessary to close the door, only external force is needed to push the door leaf to make the second needle roller disengage from the second positioning groove, and then the external force is released, and the return spring can automatically drive the door leaf to close.

[0023] According to some embodiments of the present invention, the first cam layer is further provided with a third positioning groove, which is used to cooperate with the second needle roller for positioning. The second positioning groove and the third positioning groove are respectively cooperated with the second needle roller for positioning the transmission shaft at two opening angles in the open state.

[0024] The advantage of this invention is that a third positioning groove is provided in the first cam layer. The third positioning groove is used to cooperate with the second needle roller for positioning. The second positioning groove and the third positioning groove cooperate with the second needle roller to position the drive shaft at two opening angles in the open state. This makes it convenient to position the door leaf at two different opening angles, thereby meeting the user's need to maintain the door leaf at different opening angles.

[0025] According to some embodiments of this utility model, the cam portion is symmetrically arranged on the left and right, and two first needle rollers are provided. The two first needle rollers are symmetrically arranged on the first cam layer along the symmetry line of the cam portion. The two first needle rollers respectively abut against the plunger and roll to enable the drive shaft to support the door leaf to open in two directions.

[0026] The advantage of this invention is that by symmetrically arranging the cam part on the left and right, and providing two first needle rollers, the two first needle rollers are symmetrically arranged on the first cam layer along the symmetry line of the cam part. The two first needle rollers respectively abut against the plunger and roll to enable the drive shaft to support the door leaf to open in both directions, thereby enabling the door leaf to swing open in both directions towards the doorway.

[0027] According to some embodiments of the present invention, the first cam layer is provided with two second positioning grooves. The two second positioning grooves are symmetrically arranged in the first cam layer along the symmetry line of the cam portion. The two second positioning grooves cooperate with the second needle roller to position the transmission shaft in an open state in two directions.

[0028] The advantages of this invention are: by providing two second positioning grooves on the first cam layer, the two second positioning grooves are symmetrically arranged on the first cam layer along the symmetry line of the cam portion. The two second positioning grooves cooperate with the second needle roller to position the drive shaft in the open state in both directions. Thus, when the door opens in both directions towards the doorway, the door can be positioned in the open state, eliminating the need to use external force to keep the door open, thereby facilitating use. In addition, when it is necessary to close the door, only external force is needed to push the door to disengage the second needle roller from the second positioning groove. Then, the external force is released, and the return spring automatically drives the door to close.

[0029] According to some embodiments of the present invention, the first cam layer is further provided with two third positioning grooves. The two third positioning grooves are symmetrically arranged in the first cam layer along the symmetry line of the cam portion. The two second positioning grooves and the two third positioning grooves cooperate with the second needle roller to position the transmission shaft at two opening angles in two directions of the opening state.

[0030] The advantage of this invention is that by providing two third positioning grooves in the first cam layer, the two third positioning grooves are symmetrically arranged in the first cam layer along the symmetry line of the cam portion. The two second positioning grooves and the two third positioning grooves cooperate with the second needle roller to position the drive shaft at two opening angles in the two directions of the door opening state. Thus, the door can be positioned at two opening angles when opening the door in both the inward and outward directions of the doorway, thereby meeting the user's need to maintain the door at different opening angles.

[0031] According to some embodiments of the present invention, the outer peripheral surface of the second cam layer has a first abutting section, the first abutting section is used to abut the second needle roller, the outer peripheral surface of the first cam layer has a first clearance section at the corresponding angle range of the first abutting section, the distance between the first clearance section and the axis of the drive shaft is less than the distance between the corresponding angle position of the first abutting section and the axis of the drive shaft, and the first clearance section is used to avoid the plunger.

[0032] The advantages of this invention are: by providing a first abutting section on the outer peripheral surface of the second cam layer, the first abutting section is used to abut the second needle roller, and the corresponding angle range between the outer peripheral surface of the first cam layer and the first abutting section has a first clearance section, the distance between the first clearance section and the axis of the drive shaft is less than the distance between the corresponding angle position of the first abutting section and the axis of the drive shaft, and the first clearance section is used to avoid the plunger, thereby avoiding collision and interference between the first cam layer and the plunger when the second needle roller abuts and rolls with the second cam layer.

[0033] According to some embodiments of the present invention, the cam portion further includes a third cam layer, the plunger is provided with a friction portion, the third cam layer has a friction point, and the friction portion and the friction point abut against each other to buffer the door leaf closing inertia.

[0034] The advantages of this invention are: by including a third cam layer in the cam section, and providing a friction part on the plunger, and a friction point on the third cam layer, the friction part and the friction point abut against each other to buffer the door's closing inertia. It can be understood that when the return spring drives the plunger to return to its original position, the door's swing has inertia. When the door swings to the closing angle, the inertia causes the door to pause at an angle exceeding the closing angle and swing in another direction, squeezing the return spring again. Then the return spring drives the door to return to its original position and close, causing the door to swing repeatedly before reaching the closing angle. This embodiment, by providing a friction part on the plunger and a friction point on the third cam layer, allows the friction point to abut against the friction part when the return spring drives the door to swing to the closing angle, thereby counteracting the door's closing inertia and effectively solving the problem of the door swinging back and forth before reaching the closing angle.

[0035] A door closer according to a second aspect of the present invention includes a cam motion coordination structure as described in the first aspect of the present invention.

[0036] A door closer according to an embodiment of the present utility model has at least the following beneficial effects:

[0037] 1. This utility model, through a cam motion cooperation structure, includes a housing, a plunger, a return spring, a drive shaft, and a cam portion. The plunger is slidably disposed within the housing, one end of the return spring abuts against the housing, and the other end of the return spring abuts against the plunger. The drive shaft is rotatably connected to the housing, and the cam portion is disposed on the drive shaft. It can be understood that when the door is opened, the drive shaft rotates relative to the housing, causing the rotating shaft to drive the cam portion to rotate. During the rotation of the cam portion, the cam portion can drive the plunger to slide within the housing along its own outer circumferential trajectory, allowing the plunger to compress the spring. When the door is closed, the door loses its pushing force, the elastic potential energy accumulated in the compressed spring is released, pushing the plunger back to its original position, thereby driving the cam portion to rotate and reset, closing the door, thus achieving the effect of automatic door closing.

[0038] 2. This utility model includes a first cam layer and a second cam layer arranged axially along the transmission shaft in the cam part. The first cam layer is provided with a first needle roller, and the plunger is provided with a second needle roller. When the transmission shaft rotates within a first angle range, the first needle roller rolls against the plunger. When the transmission shaft rotates within a second angle range, the second needle roller rolls against the second cam layer. It can be understood that when the door swings, the rolling of the first needle roller against the plunger and the rolling of the second needle roller against the second cam layer avoid the sliding friction between the cam part and the plunger, reduce the frictional resistance between the cam part and the plunger, reduce the wear of the cam part and the plunger, and make the cam part and the plunger less prone to damage, thus ensuring service life.

[0039] 3. By setting a first needle roller and a second needle roller, the diameters of the first needle roller and the second needle roller are small, which can reduce the space occupied by the first needle roller and the second needle roller in the door closer, making the door closer smaller in size.

[0040] 4. By setting a first needle roller and a second needle roller, the first needle roller and the second needle roller respectively serve as support components between the cam part and the plunger in the first angle range and the second angle range of the transmission shaft. This avoids the reduction of the life of the support component due to long-term use of a single support component, thereby helping to extend the service life of the door closer.

[0041] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of a door closer according to an embodiment of the present utility model;

[0044] Figure 2 This is a schematic diagram of a cam motion coordination structure according to an embodiment of the present invention;

[0045] Figure 3 for Figure 2 The diagram shows the structure of the cam section and the plunger in cooperation.

[0046] Figure 4 for Figure 3 The diagram shows the structure of the plunger;

[0047] Figure 5 for Figure 4 The top view shown;

[0048] Figure 6 for Figure 3 The diagram shows the structure of the drive shaft and cam section;

[0049] Figure 7 for Figure 6 The top view of the cam section is shown.

[0050] Reference numerals: 100-housing, 110-plunger, 120-return spring, 130-drive shaft, 140-cam section, 150-first cam layer, 160-second cam layer, 170-first needle roller, 180-second needle roller, 190-first positioning groove, 200-second positioning groove, 210-third positioning groove, 220-first abutting section, 230-first clearance section, 240-third cam layer, 250-friction section, 260-friction point. Detailed Implementation

[0051] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0052] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0053] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" and "second" are mentioned, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0054] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation, connection, and linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0055] The following description, in conjunction with the accompanying drawings, describes a cam motion coordination structure and a door closer according to an embodiment of the present invention.

[0056] This utility model aims to provide an embodiment of a cam motion coordination structure and a door closer.

[0057] Reference Figure 1 and Figure 2 In this embodiment, the door closer includes a cam motion engagement structure, wherein the cam motion engagement structure and the door closer mainly include a housing 100, a plunger 110, a return spring 120, a drive shaft 130, and a cam portion 140.

[0058] Reference Figure 3 , Figure 4 and Figure 5 For plunger 110, plunger 110 is slidably disposed within housing 100.

[0059] The return spring 120 has one end abutting against the housing 100 and the other end abutting against the plunger 110.

[0060] Refer again Figure 3 For the drive shaft 130, the drive shaft 130 is rotatably connected to the housing 100.

[0061] Specifically, a bearing is provided between the drive shaft 130 and the housing 100, thereby making the rotation of the drive shaft 130 smoother.

[0062] Refer again Figure 3 , Figure 6 and Figure 7For the cam part 140, the cam part 140 is mounted on the drive shaft 130, and the cam part 140 is used to drive the plunger 110 to compress the return spring 120.

[0063] This embodiment comprises a housing 100, a plunger 110, a return spring 120, a drive shaft 130, and a cam portion 140. The plunger 110 is slidably disposed within the housing 100. One end of the return spring 120 abuts against the housing 100, and the other end abuts against the plunger 110. The drive shaft 130 is rotatably connected to the housing 100. The cam portion 140 is disposed on the drive shaft 130. When the door is opened, the drive shaft 130 rotates relative to the housing, causing the cam portion 140 to rotate. During the rotation of the cam portion 140, the cam portion 140 can drive the plunger 110 to slide within the housing along its own peripheral trajectory, allowing the plunger 110 to compress the spring. When the door is closed, the door loses its pushing force, and the elastic potential energy accumulated in the compressed spring is released, pushing the plunger 110 back to its original position. This, in turn, drives the cam portion 140 to rotate back to its original position, closing the door and achieving the effect of automatic door closing.

[0064] Specifically, the cam section 140 includes a first cam layer 150 and a second cam layer 160 arranged along the axial direction of the drive shaft 130. The first cam layer 150 is provided with a first needle roller 170, and the plunger 110 is provided with a second needle roller 180. When the drive shaft 130 rotates within a first angle range, the first needle roller 170 abuts against the plunger 110 and rolls. When the drive shaft 130 rotates within a second angle range, the second needle roller 180 abuts against the second cam layer 160 and rolls.

[0065] Understandably, when the door swings, the first needle roller 170 and the plunger 110 abut against each other and the second needle roller 180 and the second cam layer 160 abut against each other, which avoids sliding friction between the cam part 140 and the plunger 110, reduces the frictional resistance between the cam part 140 and the plunger 110, reduces the wear of the cam part 140 and the plunger 110, and makes the cam part 140 and the plunger 110 less prone to damage, thus ensuring their service life.

[0066] In addition, by setting the first needle roller 170 and the second needle roller 180 in this embodiment, the diameters of the first needle roller 170 and the second needle roller 180 are small, which can reduce the space occupied by the first needle roller 170 and the second needle roller 180 in the door closer, making the door closer smaller in size.

[0067] It needs to be explained that when the door closer is installed on the door leaf, the installation of the door closer can be hidden inside the door leaf, realizing the concealed installation of the door closer. At the same time, it can eliminate the need to dig a pit in the ground to install the door closer. In order for the door closer to be installed inside the door leaf, the size of the door closer needs to be designed to be relatively small. By setting the first needle roller 170 and the second needle roller 180, the diameter of the first needle roller 170 and the second needle roller 180 is small, which allows for the arrangement and use of the door closer in the limited space.

[0068] Furthermore, by setting the first needle roller 170 and the second needle roller 180 in this embodiment, the first needle roller 170 and the second needle roller 180 respectively serve as support components between the cam portion 140 and the plunger 110 within the first angle range and the second angle range of the transmission shaft 130. This avoids the reduction in the lifespan of the support component due to long-term use of a single support component, thereby helping to extend the service life of the door closer.

[0069] In some specific embodiments, the plunger 110 is provided with a first positioning groove 190, which cooperates with the first needle roller 170 to position the drive shaft 130 in the closed state, thereby making the door leaf more stable in the closed state and preventing the door leaf from shaking.

[0070] In some specific embodiments, the plunger 110 is provided with a first inclined surface that abuts against the first needle roller 170, thereby enabling the first inclined surface to guide the first needle roller 170 and making the rolling of the first needle roller 170 on the plunger 110 smoother.

[0071] Furthermore, the first positioning groove 190 is provided on the first inclined surface.

[0072] In some specific embodiments, the first cam layer 150 is provided with a second positioning groove 200. The second positioning groove 200 cooperates with the second needle roller 180 to position the drive shaft 130 in the open state. Thus, the door can be positioned after the door is opened, and the door can be maintained in the open state through the cooperation of the second positioning groove 200 and the second needle roller 180, eliminating the need to use external force to keep the door in the open state, thereby making it convenient to use. In addition, when it is necessary to close the door, it is only necessary to use external force to push the door to make the second needle roller 180 disengage from the second positioning groove 200, and then release the external force, and the return spring 120 can automatically drive the door to close.

[0073] Furthermore, the first cam layer 150 is also provided with a third positioning groove 210, which is used to cooperate with the second needle roller 180 for positioning. The second positioning groove 200 and the third positioning groove 210 cooperate with the second needle roller 180 to position the drive shaft 130 at two opening angles in the open state, thereby facilitating the positioning of the door leaf at two different opening angles, and thus adapting to the user's need to maintain the door leaf at different opening angles.

[0074] In some specific embodiments, the cam portion 140 is symmetrically arranged on the left and right, and two first needle rollers 170 are provided. The two first needle rollers 170 are symmetrically arranged on the first cam layer 150 along the symmetry line of the cam portion 140. The two first needle rollers 170 respectively abut against the plunger 110 and roll to make the drive shaft 130 support the door leaf to open in two directions, thereby enabling the door leaf to swing open in both directions towards the doorway.

[0075] Furthermore, the first cam layer 150 is provided with two second positioning grooves 200. The two second positioning grooves 200 are symmetrically arranged in the first cam layer 150 along the symmetry line of the cam portion 140. The two second positioning grooves 200 cooperate with the second needle roller 180 to position the drive shaft 130 in the open state in both directions. Thus, when the door is opened in both directions towards the door, the door can be positioned in the open state, eliminating the need to use external force to keep the door in the open state, thereby facilitating use. In addition, when it is necessary to close the door, only external force is needed to push the door to make the second needle roller 180 disengage from the second positioning groove 200. Then, the external force is released, and the return spring 120 can automatically drive the door to close.

[0076] Furthermore, the first cam layer 150 is also provided with two third positioning grooves 210. The two third positioning grooves 210 are symmetrically arranged in the first cam layer 150 along the symmetry line of the cam portion 140. The two second positioning grooves 200 and the two third positioning grooves 210 cooperate with the second needle roller 180 to position the drive shaft 130 at two opening angles in two directions of the door opening state. Thus, the door can be positioned at two opening angles when the door opens in both the inward and outward directions of the doorway, thereby adapting to the user's need to maintain the door at different opening angles.

[0077] In some specific embodiments, the outer peripheral surface of the second cam layer 160 has a first abutting section 220, which is used to abut the second needle roller 180. The corresponding angle range between the outer peripheral surface of the first cam layer 150 and the first abutting section 220 has a first clearance section 230. The distance between the first clearance section 230 and the axis of the drive shaft 130 is less than the distance between the corresponding angle position of the first abutting section 220 and the axis of the drive shaft 130. The first clearance section 230 is used to avoid the plunger 110.

[0078] In this embodiment, a first abutting section 220 is provided on the outer peripheral surface of the second cam layer 160. The first abutting section 220 is used to abut the second needle roller 180. The corresponding angle range between the outer peripheral surface of the first cam layer 150 and the first abutting section 220 has a first clearance section 230. The distance between the first clearance section 230 and the axis of the drive shaft 130 is less than the distance between the corresponding angle position of the first abutting section 220 and the axis of the drive shaft 130. The first clearance section 230 is used to avoid the plunger 110. Thus, collision interference between the first cam layer 150 and the plunger 110 is avoided when the second needle roller 180 abuts and rolls with the second cam layer 160.

[0079] In some specific embodiments, the cam portion 140 further includes a third cam layer 240, the plunger 110 is provided with a friction portion 250, the third cam layer 240 has a friction point 260, and the friction portion 250 and the friction point 260 abut against each other to buffer the door leaf closing inertia.

[0080] This embodiment further includes a third cam layer 240 in the cam part 140, a friction part 250 in the plunger 110, and a friction point 260 in the third cam layer 240. The friction part 250 and the friction point 260 abut against each other to buffer the door leaf's closing inertia. It can be understood that when the return spring 120 drives the plunger 110 to return to its original position, the door leaf's swing has inertia. When the door leaf swings to the closing angle, the door leaf, affected by inertia, will cause the door leaf to stop at an angle exceeding the closing angle and swing in another direction, squeezing the return spring 120 again. Then the return spring 120 drives the door leaf to return to its original position and close the door. This causes the door leaf to swing back and forth before the closing angle stops. In this embodiment, by providing a friction part 250 in the plunger 110 and a friction point 260 in the third cam layer 240, when the return spring 120 drives the door leaf to swing to the closing angle, the friction point 260 abuts against the friction part 250, thereby offsetting the door leaf's closing inertia and helping to solve the problem of the door leaf swinging back and forth before the closing angle stops.

[0081] In the description of this specification, references to terms such as "an embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0082] The terms "first," "second," "third," "fourth," etc. (if applicable) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0083] It should also be noted that, in the description of this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0084] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may also include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or apparatus.

[0085] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0086] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A cam motion fitting structure characterized by, The utility model relates to a door closer, which comprises: a housing (100); a plunger (110) slidingly arranged in the housing (100); a return spring (120) abutting one end of the housing (100) and the other end of the plunger (110); a transmission shaft (130) rotatably connected with the housing (100); a cam portion (140) arranged on the transmission shaft (130) for driving the plunger (110) to compress the return spring (120); wherein the cam portion (140) comprises a first cam layer (150) and a second cam layer (160) arranged along the axial direction of the transmission shaft (130), the first cam layer (150) is provided with a first needle roller (170), the plunger (110) is provided with a second needle roller (180), when the transmission shaft (130) rotates in a first angle range, the first needle roller (170) rolls against the plunger (110), when the transmission shaft (130) rotates in a second angle range, the second needle roller (180) rolls against the second cam layer (160).

2. A camming arrangement according to claim 1, wherein The plunger (110) is provided with a first positioning groove (190), the first positioning groove (190) cooperates with the first needle roller (170) to position the transmission shaft (130) in a closed door state.

3. The camming arrangement of claim 1 wherein, The first cam layer (150) is provided with a second positioning groove (200), the second positioning groove (200) cooperates with the second needle roller (180) to position the transmission shaft (130) in an open door state.

4. A camming arrangement according to claim 3, wherein The first cam layer (150) is further provided with a third positioning groove (210), the third positioning groove (210) is used for cooperating with the second needle roller (180) to position, the second positioning groove (200) and the third positioning groove (210) respectively cooperate with the second needle roller (180) to position to position the transmission shaft (130) in two open door angles of an open door state.

5. The camming arrangement of claim 1 wherein, The cam portion (140) is symmetrically arranged left and right, the first needle roller (170) is provided with two, two first needle rollers (170) are symmetrically arranged in the first cam layer (150) along the symmetry line of the cam portion (140), two first needle rollers (170) respectively roll against the plunger (110) to make the transmission shaft (130) support the door leaf to open in two directions.

6. A camming arrangement according to claim 5, wherein The first cam layer (150) is provided with two second positioning grooves (200), two second positioning grooves (200) are respectively symmetrically arranged in the first cam layer (150) along the symmetry line of the cam portion (140), two second positioning grooves (200) respectively cooperate with the second needle roller (180) to position the transmission shaft (130) in two directions of an open door state.

7. A camming arrangement according to claim 6, wherein The first cam layer (150) is further provided with two third positioning grooves (210), the two third positioning grooves (210) are respectively arranged on the first cam layer (150) along the symmetry line of the cam part (140), and the two second positioning grooves (200) and the two third positioning grooves (210) are respectively matched with the second needle roller (180) to position the transmission shaft (130) at two door opening angles in two directions.

8. The camming arrangement of claim 1 wherein, The outer circumferential surface of the second cam layer (160) has a first abutting section (220) for abutting the second needle roller (180), and the corresponding angular range of the outer circumferential surface of the first cam layer (150) and the first abutting section (220) has a first avoiding section (230), the distance between the first avoiding section (230) and the axis of the transmission shaft (130) is smaller than the distance between the corresponding angular position of the first abutting section (220) and the axis of the transmission shaft (130), and the first avoiding section (230) is used for avoiding the plunger (110).

9. The camming arrangement of claim 1 wherein, The cam part (140) further comprises a third cam layer (240), the plunger (110) is provided with a friction part (250), the third cam layer (240) has a friction point (260), and the friction part (250) and the friction point (260) abut and rub to buffer the door leaf closing inertia.

10. A door closer characterised in that, A cam motion matching structure comprising any one of claims 1 to 9.

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