Door closer

Abstract

The invention discloses a door closer. The door closer comprises a shell; a transmission shaft having a cam; the first piston divides an inner cavity of the shell into a first oil cavity and a second oil cavity and abuts against the cam for transmission; the reset spring is used for pushing the first piston to move towards the second oil cavity to reset so as to drive the door leaf to close. The one-way valve is arranged on the first piston and used for containing hydraulic oil to flow from the first oil cavity to the second oil cavity, a first oil channel is formed in the side wall of the shell and communicated with the first oil cavity and the second oil cavity, and two first oil ports are formed in the side wall of the second oil cavity; the speed regulating valve comprises a first valve body, a second piston, a first spring, a first valve element and a second spring. The second oil channel communicates with the first oil cavity and the second oil cavity, the second spring is used for driving the first valve element to seal the second oil channel, and the first piston moves to reset to push the first valve element to open the first oil channel. According to the door closer, three-stage speed door closing can be achieved, and door closing efficiency, safety and smooth locking are all considered.

Description

Technical Field

[0001] The present invention relates to the technical field of door closers, and in particular to a door closer. Background Art

[0002] The door closer is a machine that automatically closes the door. It is a spring-like hydraulic device on the door head. When the door is opened, it can be compressed and then released to automatically close the door. It acts like a spring door and can ensure that the door is accurately and promptly closed to its initial position after being opened.

[0003] In the related art, the door closer includes a housing, a transmission shaft, a cam, a piston and a return spring. The transmission shaft is rotatably connected to the housing, the cam is arranged on the transmission shaft, the piston is slidably arranged in the housing, and one end of the return spring abuts against the end inner wall of the housing, and the other end abuts against the piston.

[0004] During installation, one of the transmission shaft and the housing is installed on the door leaf, and the other of the transmission shaft and the housing is installed on the door frame or the ground.

[0005] Existing door closers usually close the door at a constant speed or at two speeds when closing the door automatically.

[0006] For constant speed closing, that is, the closing speed of the door leaf remains constant during the automatic closing process of the door closer.

[0007] For two-stage speed closing, that is, during the automatic closing process of the door closer, the door leaf can close at different speeds in two closing angle intervals. It can be low-speed closing in the front angle interval of closing and high-speed closing in the rear angle interval of closing, or high-speed closing in the front angle interval of closing and low-speed closing in the rear angle interval of closing.

[0008] However, for constant speed closing, if the closing speed is too fast, the door leaf may easily pinch people at the door frame, resulting in low safety; if the closing speed is too slow, the door closing time is long and the closing efficiency is low; for two-speed closing, if the door is closed at a low speed in the front angle range and at a high speed in the rear angle range, the door closing efficiency is low and the door leaf may easily pinch people at the door frame, resulting in low safety; if the door is closed at a high speed in the front angle range and at a low speed in the rear angle range, the door closer may not have enough force when locking the door leaf, resulting in the door leaf being unable to close smoothly. Therefore, it is difficult for existing door closers to take into account closing efficiency, safety and smooth locking at the same time. Summary of the invention

[0009] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a door closer that can achieve three-level door closing speeds and take into account door closing efficiency, safety and smooth locking.

[0010] A door closer according to an embodiment of the present invention comprises: case; A transmission shaft, rotatably disposed on the housing, and having a cam; A first piston is slidably disposed in the housing, divides the inner cavity of the housing into a first oil cavity and a second oil cavity, and abuts against the cam for transmission; A return spring, located in the first oil chamber, is used to push the first piston to move toward the second oil chamber and return to the original position so as to drive the door leaf to close; a one-way valve, arranged on the first piston, accommodating hydraulic oil to flow from the first oil chamber to the second oil chamber, a first oil passage is arranged on the side wall of the housing, the first oil passage is connected to the first oil chamber and the second oil chamber, and two first oil ports are formed on the side wall of the second oil chamber, the two first oil ports are arranged in sequence along the moving direction of the first piston, and the two first oil ports are connected to the first oil passage; The speed regulating valve comprises a first valve body, a second piston, a first spring, a first valve core and a second spring, wherein the first valve body is arranged at an end of the second oil chamber away from the first oil chamber, the second piston is slidably arranged in the first valve body, and the first spring is used to drive the second piston to approach the first piston; The second oil passage passes through the side wall of the shell, the first valve body and the second piston in sequence, and connects the first oil chamber and the second oil chamber. The first valve core is slidably arranged in the second piston. The second spring is used to drive the first valve core to seal the second oil passage. The first piston moves and resets to push the first valve core to open the first oil passage.

[0011] A door closer according to an embodiment of the present invention has at least the following beneficial effects: 1. The present invention arranges a housing, a transmission shaft, a first piston and a return spring. The transmission shaft is rotatably arranged on the housing, the transmission shaft has a cam, the first piston is slidably arranged in the housing, the first piston divides the inner cavity of the housing into a first oil cavity and a second oil cavity, the first piston abuts against the cam for transmission, the return spring is located in the first oil cavity, the return spring is used to push the first piston to move to the second oil cavity for return to drive the door leaf to close, thereby achieving the effect that the door closer automatically drives the door leaf to close through the return spring.

[0012] 2. The present invention is provided with a one-way valve, which is arranged on the first piston. The one-way valve allows hydraulic oil to flow from the first oil chamber to the second oil chamber. The side wall of the shell is provided with a first oil channel, which connects the first oil chamber and the second oil chamber. The side wall of the second oil chamber is formed with two first oil ports, which are arranged in sequence along the moving direction of the first piston. The two first oil ports are both connected to the first oil channel. It can be understood that when the door closer drives the door leaf to close the door, the return spring drives the first piston to move in the direction close to the second oil chamber, and the hydraulic oil in the second oil chamber is squeezed by the first piston, so that the hydraulic oil in the second oil chamber enters the first oil channel from the first oil port to flow to the first oil chamber. During the movement of the plug, the two first oil ports are unobstructed at the beginning, and the hydraulic oil in the second oil chamber can enter the first oil channel from the two first oil ports, so that the door closer can drive the door leaf to close at high speed in the front closing angle range, thereby allowing the door leaf to swing quickly and close in the front closing angle range, thereby improving the closing efficiency of the door leaf. When the first piston continues to move and blocks one first oil port, the hydraulic oil in the second oil chamber can only enter the first oil channel from one first oil port, so that the door closer can drive the door leaf to close at low speed in the middle closing angle range, thereby allowing the door leaf to swing at low speed before entering the door frame, thereby avoiding the door leaf closing too quickly and causing the door leaf to pinch people at the door frame, thereby improving safety.

[0013] 3. The present invention sets a speed regulating valve and a second oil passage, wherein the speed regulating valve includes a first valve body, a second piston, a first spring, a first valve core and a second spring. The first valve body is set at an end of the second oil chamber away from the first oil chamber, the second piston is slidably set in the first valve body, and the first spring is used to drive the second piston to approach the first piston; the second oil passage sequentially passes through the side wall of the shell, the first valve body and the second piston, and connects the first oil chamber and the second oil chamber. The first valve core is slidably set in the second piston, and the second spring is used to drive the first valve core to seal the second oil passage. The first piston moves and resets to push the first valve The core opens the first oil channel. It can be understood that, in the rear closing angle range when the door closer drives the door leaf to close the door, the first piston pushes the first valve core to open the first oil channel, and then pushes the second piston to move, so that the hydraulic oil in the second oil chamber can synchronously flow to the first oil chamber through the second oil channel, thereby increasing the return oil speed from the second oil chamber to the first oil chamber, so that the door closer can increase the swinging speed of the door leaf in the rear closing angle range when driving the door leaf to close the door, and then, the door leaf swings highly after entering the door frame, so that the door leaf can have enough speed to lock, thereby ensuring that the door leaf can be locked smoothly.

[0014] 4. The present invention sets a first spring, which is used to drive the second piston to approach the first piston. Therefore, when the first piston releases the second piston, the first spring can drive the second piston to restore its position, thereby ensuring the normal use of the second piston when the door is closed next time.

[0015] 5. The present invention arranges a second spring, and the second spring is used to drive the first valve core to seal the second oil channel. Therefore, when the first piston releases the first valve core, the second spring can drive the first valve core to restore the sealing of the second oil channel, thereby preventing the hydraulic oil in the first oil chamber from flowing back from the second oil channel to the second oil chamber. At the same time, it ensures that the second oil channel can normally perform the function of increasing the swing speed of the door leaf in the rear closing angle range when the door is closed next time.

[0016] According to some embodiments of the present invention, the side wall of the first valve body has a first hole, which is used to form a part of the second oil channel. The outer peripheral wall of the second piston is provided with a first annular groove, which is used to form a part of the second oil channel. The first annular groove is connected to the orifice of the first hole, and the groove width of the first annular groove along the sliding direction of the second piston is greater than the orifice diameter of the first hole.

[0017] The benefit is that: the present invention provides a first hole on the side wall of the first valve body, the first hole is used to form a part of the second oil channel, and a first annular groove is provided on the outer peripheral wall of the second piston, the first annular groove is used to form a part of the second oil channel, the first annular groove is connected to the orifice of the first hole, and the groove width of the first annular groove along the sliding direction of the second piston is greater than the orifice diameter of the first hole. It can be understood that during the closing process of the door leaf, the first piston will push the second piston to move, and by making the groove width of the first annular groove along the sliding direction of the second piston greater than the orifice diameter of the first hole, the first annular groove can remain connected to the first hole during the movement of the second piston, thereby avoiding the misalignment of the first annular groove and the orifice of the first hole, which may cause the second oil channel to be unable to pass oil, and further, ensure that the second oil channel can remain unobstructed during the movement of the second piston.

[0018] According to some embodiments of the present invention, the side wall of the first valve body has a first hole, the first hole is used to form a part of the second oil channel, and the first valve body is threadedly connected with a first valve needle, and the first valve needle is used to adjust the opening of the first hole to adjust the oil flow speed of the second oil channel.

[0019] Advantageously, in the present invention, a first hole is provided on the side wall of the first valve body, the first hole is used to form a part of the second oil passage, and a first valve needle is threadedly connected to the first valve body, the first valve needle is used to adjust the opening of the first hole to adjust the oil flow rate of the second oil passage, thereby, the closing swing speed of the door leaf can be adjusted by adjusting the oil flow rate of the second oil passage, thereby making the closing swing speed of the door leaf driven by the door closer adjustable.

[0020] According to some embodiments of the present invention, the second piston is provided with a T-shaped hole, which is used to form a part of the second oil channel. The small-diameter port of the T-shaped hole is connected to the second oil chamber. The first valve core is configured as a T-shaped needle. The T-shaped hole accommodates the sliding of the first valve core. When the second spring squeezes the first valve core to seal the T-shaped hole, the end of the first valve core protrudes out of the small-diameter port of the T-shaped hole.

[0021] What is beneficial is that: the present invention provides a T-hole on the second piston, the T-hole is used to form a part of the second oil channel, the small-diameter port of the T-hole is connected to the second oil chamber, the first valve core is configured as a T-type needle, the T-hole accommodates the sliding of the first valve core, and when the second spring squeezes the first valve core to seal the T-hole, the end of the first valve core protrudes out of the small-diameter port of the T-hole. It can be understood that by providing the T-hole in the second piston to cooperate with the first valve core, the T-hole can limit the first valve core to prevent the second spring from completely squeezing the first valve core out of the second piston. At the same time, when the second spring squeezes the first valve core to seal the T-hole, the end of the first valve core protrudes out of the small-diameter port of the T-hole, so that the first piston can first push the end of the first valve core to open the T-hole and then push the second piston to move, thereby allowing the second oil channel to remain open during the process of the first piston pushing the second piston to move.

[0022] According to some embodiments of the present invention, the first valve core includes a large diameter needle segment and a small diameter needle segment, the T-shaped hole includes a large diameter hole segment and a small diameter hole segment, the small diameter needle segment is clearance-matched with the small diameter hole segment, the cross-section of the outer peripheral surface of the large diameter needle segment is polygonal, the edges and corners of the outer peripheral surface of the large diameter needle segment are slidingly matched with the large diameter hole segment, the plane of the outer peripheral surface of the large diameter needle segment is clearance-matched with the large diameter hole segment, and the end face of the large diameter needle segment close to the small diameter needle segment abuts against the end face of the small diameter hole segment to seal the T-shaped hole.

[0023] Advantageously, the present invention enables the first valve core to include a large-diameter needle segment and a small-diameter needle segment, the T-shaped hole to include a large-diameter hole segment and a small-diameter hole segment, the small-diameter needle segment and the small-diameter hole segment are clearance-matched, the cross-section of the outer peripheral surface of the large-diameter needle segment is polygonal, the edges and corners of the outer peripheral surface of the large-diameter needle segment are slidingly matched with the large-diameter hole segment, the plane of the outer peripheral surface of the large-diameter needle segment is clearance-matched with the large-diameter hole segment, the end surface of the large-diameter needle segment close to the small-diameter needle segment abuts against the end surface of the small-diameter hole segment to seal the T-shaped hole, and it can be understood that by placing the large-diameter needle The cross-section of the outer circumferential surface of the segment is polygonal, the edges and corners of the outer circumferential surface of the large-diameter needle segment are slidably matched with the large-diameter hole segment, and the plane of the outer circumferential surface of the large-diameter needle segment is gap-matched with the large-diameter hole segment, so that the outer circumferential surface of the large-diameter needle segment can slide with the large-diameter hole segment while ensuring that there is a gap between the outer circumferential surface of the large-diameter needle segment and the large-diameter hole segment to accommodate the passage of hydraulic oil, thereby, the gap between the outer circumferential surface of the large-diameter needle segment and the large-diameter hole segment and the gap between the small-diameter needle segment and the small-diameter hole segment can form a part of the second oil channel.

[0024] According to some embodiments of the present invention, the speed regulating valve also includes a distance regulating needle, which is threadedly connected to the side wall of the first valve body, the distance regulating needle has a reducing section, the second piston has a distance regulating groove arranged along the radial direction of the second piston, the reducing section and the distance regulating groove are clearance matched, the reducing section and the distance regulating groove are clearance matched, and the distance regulating needle is used to adjust the position of the second piston in the second oil chamber.

[0025] Advantageously, the present invention makes the speed regulating valve further include an adjusting needle, which is threadedly connected to the side wall of the first valve body, and has a reducing section. The second piston has an adjusting groove arranged along the radial direction of the second piston, and the reducing section and the adjusting groove have a clearance fit. The reducing section and the adjusting groove have a clearance fit, and the adjusting needle is used to adjust the position of the second piston in the second oil chamber. It can be understood that by adjusting the depth of the adjusting needle in the first valve body, the positions of different diameters of the reducing section can be made to fit with the adjusting groove, thereby adjusting the movable range of the second piston and adjusting the position of the second piston in the second oil chamber, thereby facilitating changing the door leaf angle position of the door closer to start the speed regulating valve.

[0026] According to some embodiments of the present invention, the pitch-adjusting groove has an inclined wall opening, and the inclination of the inclined wall opening is consistent with the inclination of the diameter-changing section.

[0027] Advantageously, the present invention provides the pitch adjusting groove with an inclined wall opening, the inclination of which is consistent with the inclination of the diameter-changing section. Thus, when the diameter-changing section and the pitch adjusting groove are abutted to limit, the inclined wall opening can fit with one side of the diameter-changing section, thereby making the cooperation between the diameter-changing section and the pitch adjusting groove more stable.

[0028] According to some embodiments of the present invention, the distance adjusting groove passes through the second piston, and a limiting hole is further provided on the side wall of the first valve body. One end of the distance adjusting needle passes through the distance adjusting groove and cooperates with the limiting hole for limiting.

[0029] Advantageously, the present invention allows the distance adjusting groove to pass through the second piston, and a limiting hole is further provided on the side wall of the first valve body. One end of the distance adjusting needle passes through the distance adjusting groove and cooperates with the limiting hole to limit the position, thereby making the support of the distance adjusting needle by the first valve body more stable, and furthermore, making the limiting of the distance adjusting needle to the second piston more stable.

[0030] According to some embodiments of the present invention, a third spring is arranged in the limiting hole, two ends of the second spring respectively abut against the bottom wall of the limiting hole and the end of the distance adjusting needle, and the third spring supports the distance adjusting needle to press the distance adjusting needle.

[0031] Advantageously, the present invention provides a third spring in the limiting hole, and the two ends of the second spring respectively abut against the bottom wall of the limiting hole and the end of the distance adjusting needle, and the third spring supports the distance adjusting needle to press the distance adjusting needle. Thus, the third spring supports the distance adjusting needle, so that the distance adjusting needle will not loosen due to the clearance of the threaded fit between the distance adjusting needle and the first valve body, thereby making the distance adjusting needle more stable.

[0032] According to some embodiments of the present invention, two second valve needles are threadedly connected to the housing, and the two second valve needles are respectively used to adjust the openings of the two first oil ports to adjust the oil flow speed of the two first oil ports.

[0033] What is beneficial is that: the present invention has two second valve needles threadedly connected to the shell body, and the two second valve needles are respectively used to adjust the openings of the two first oil ports to adjust the oil flow speed of the two first oil ports. Therefore, by adjusting the openings of the two first oil ports respectively through the two second valve needles, the closing swing speeds of the door leaf in the front closing angle range and the middle closing angle range can be adjusted respectively, thereby making the closing swing speed of the door leaf driven by the door closer adjustable.

[0034] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 This is a schematic structural diagram of a door closer according to an embodiment of the present invention; Figure 2 for Figure 1 The schematic diagram of the structure of the cam and the first piston; Figure 3 for Figure 1 An enlarged view of point A is shown; Figure 4 for Figure 1 An enlarged view of point B is shown; Figure 5 for Figure 1 CC cross-sectional view is shown.

[0037] Figure numerals: 100-housing, 110-transmission shaft, 120-cam, 130-first piston, 140-first oil chamber, 150-second oil chamber, 160-reset spring, 170-check valve, 180-first oil channel, 190-first oil port, 200-speed regulating valve, 210-first valve body, 220-second piston, 230-first spring, 240-first valve core, 250-second spring, 260-second oil channel, 270-first hole, 280-first annular groove, 290-first valve needle, 300-T-type hole, 310-large diameter needle section, 320-small diameter needle section, 330-large diameter hole section, 340-small diameter hole section, 350-distance adjusting needle, 360-diameter reducing section, 370-distance adjusting groove, 380-oblique wall opening Part, 390-limiting hole, 400-third spring, 410-second valve needle, 420-first layer, 430-second layer, 440-first roller needle, 450-second roller needle, 460-first positioning groove, 470-second positioning groove, 480-third positioning groove, 490-third piston, 500-left chamber, 510-right chamber, 520-pressure reducing valve, 530-second valve seat, 540-second valve core, 550-first through hole, 560-pressure reducing hole, 570-first filter plate, 580-first sliding sleeve, 590-core, 600-cover, 610-external tooth gasket, 620-locking screw, 630-U-shaped sealing ring, 640-safety valve hole, 650-safety valve bead, 660-safety valve spring. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] In the description of the present invention, it is necessary to understand that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of first and second, this is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation, connection and connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The following is combined with Figure 1-5 A door closer according to an embodiment of the present invention is described.

[0043] The present invention aims to provide an embodiment of a door closer.

[0044] Reference Figure 1 In this embodiment, a door closer mainly includes a housing 100 , a transmission shaft 110 , a first piston 130 , a return spring 160 , a one-way valve 170 , a speed regulating valve 200 and a second oil passage 260 .

[0045] In installation, one of the transmission shaft 110 and the housing 100 is installed on the door leaf, and the other of the transmission shaft 110 and the housing 100 is installed on the door frame or the ground.

[0046] The transmission shaft 110 is rotatably disposed on the housing 100 , and the transmission shaft 110 has a cam 120 .

[0047] Reference Figure 2 In some specific embodiments, the cam 120 includes a first layer 420 and a second layer 430 arranged along the axial direction of the transmission shaft 110, the first layer 420 is provided with a first needle roller 440, and the first piston 130 is provided with a second needle roller 450. When the transmission shaft 110 rotates within a first angle range, the first needle roller 440 rolls in contact with the first piston 130, and when the transmission shaft 110 rotates within a second angle range, the second needle roller 450 rolls in contact with the second layer 430.

[0048] It can be understood that when the door leaf swings, the first roller 440 and the first piston 130 are abutted and rolled, and the second roller 450 and the second layer 430 are abutted and rolled, so that the sliding friction between the cam 120 and the first piston 130 is avoided, the friction resistance between the cam 120 and the first piston 130 is reduced, and the wear of the cam 120 and the first piston 130 is reduced, so that the cam 120 and the first piston 130 are not easily damaged, thereby ensuring the service life.

[0049] In addition, in this embodiment, by providing the first needle roller 440 and the second needle roller 450, the diameters of the first needle roller 440 and the second needle roller 450 are small, which can reduce the space occupied by the first needle roller 440 and the second needle roller 450 in the door closer, making the door closer smaller.

[0050] It needs to be explained that when the door closer is installed in the door leaf, the door closer can be hidden inside the door leaf, thereby realizing concealed installation of the door closer. At the same time, it can avoid digging a hole on the ground to install the door closer. In order to enable the door closer to be installed in the door leaf, the volume of the door closer needs to be designed to be relatively small. By providing the first needle roller 440 and the second needle roller 450, the diameters of the first needle roller 440 and the second needle roller 450 are small, so they can be arranged and used in the limited space of the door closer.

[0051] Furthermore, in this embodiment, by disposing the first needle roller 440 and the second needle roller 450, the first needle roller 440 and the second needle roller 450 serve as support components between the cam 120 and the first piston 130 in the first angle range and the second angle range of the transmission shaft 110 respectively, thereby avoiding long-term use of one support component and causing the life of the support component to be reduced, which is beneficial to extending the service life of the door closer.

[0052] In some specific embodiments, the first piston 130 is provided with a first positioning groove 460, and the first positioning groove 460 cooperates with the first roller needle 440 to position the transmission shaft 110 in the closed state, thereby making the position of the door leaf in the closed state more stable and preventing the door leaf from shaking.

[0053] In some specific embodiments, the first layer 420 is provided with a second positioning groove 470, and the second positioning groove 470 cooperates with the second roller needle 450 to position the drive shaft 110 in the door-opening state, so that the door leaf can be positioned after opening, so that the door leaf can be maintained in the door-opening state through the cooperation of the second positioning groove 470 and the second roller needle 450, eliminating the need to use external force to keep the door leaf in the door-opening state, thereby facilitating use. In addition, when the door needs to be closed, it is only necessary to use external force to push the door leaf so that the second roller needle 450 disengages from the second positioning groove 470, and then remove the external force, and the reset spring 160 can automatically drive the door leaf to close.

[0054] Furthermore, the first layer 420 is also provided with a third positioning groove 480, and the third positioning groove 480 is used to cooperate with the second roller needle 450 for positioning. The second positioning groove 470 and the third positioning groove 480 respectively cooperate with the second roller needle 450 for positioning to position the drive shaft 110 at two door opening angles in the door opening state, thereby facilitating the positioning of the door leaf at two different door opening angles, and further, meeting the user's need to maintain the door leaf at different door opening angles.

[0055] In some specific embodiments, the cam 120 is symmetrically arranged on the left and right, and two first rollers 440 are arranged symmetrically on the first layer 420 along the symmetry line of the cam 120. The two first rollers 440 respectively abut and roll with the first piston 130 to enable the transmission shaft 110 to support the door leaf to open in two directions, thereby allowing the door leaf to swing open in both directions toward the inside and outside of the door.

[0056] Furthermore, the first layer 420 is provided with two second positioning grooves 470, and the two second positioning grooves 470 are symmetrically arranged on the first layer 420 along the symmetry line of the cam 120, and the two second positioning grooves 470 respectively cooperate with the second needle roller 450 to position the drive shaft 110 in the door opening state in two directions, so that when the door leaf is opened in both directions toward the inside and outside of the doorway, the door leaf can be positioned in the door opening state, eliminating the need to use external force to keep the door leaf in the door opening state, thereby facilitating use. In addition, when the door needs to be closed, it is only necessary to use external force to push the door leaf so that the second needle roller 450 disengages from the second positioning groove 470, and then remove the external force, and the reset spring 160 can automatically drive the door leaf to close.

[0057] Furthermore, the first layer 420 is also provided with two third positioning grooves 480, and the two third positioning grooves 480 are symmetrically arranged on the first layer 420 along the symmetry line of the cam 120, and the two second positioning grooves 470 and the two third positioning grooves 480 are respectively cooperated with the second roller needle 450 to position the drive shaft 110 at two door opening angles in the door opening state in two directions, so that the door leaf can be positioned at two door opening angles when opening the door leaf in both directions inward and outward of the doorway, thereby meeting the user's need to maintain the door leaf at different door opening angles.

[0058] The first piston 130 is slidably disposed in the housing 100 . The first piston 130 divides the inner cavity of the housing 100 into a first oil cavity 140 and a second oil cavity 150 . The first piston 130 abuts against the cam 120 for transmission.

[0059] The return spring 160 is located in the first oil chamber 140 , and is used to push the first piston 130 to move toward the second oil chamber 150 to return to its original position, so as to drive the door leaf to close.

[0060] In this embodiment, a housing 100, a transmission shaft 110, a first piston 130 and a return spring 160 are arranged. The transmission shaft 110 is rotatably arranged on the housing 100. The transmission shaft 110 has a cam 120. The first piston 130 is slidably arranged in the housing 100. The first piston 130 divides the inner cavity of the housing 100 into a first oil chamber 140 and a second oil chamber 150. The first piston 130 is in abutment with the cam 120 for transmission. The return spring 160 is located in the first oil chamber 140. The return spring 160 is used to push the first piston 130 to move to the second oil chamber 150 for reset so as to drive the door leaf to close. Thus, the door closer automatically drives the door leaf to close through the return spring 160.

[0061] Reference Figure 3 In some specific embodiments, a third piston 490 is further provided in the housing 100. The third piston 490 is located between the first piston 130 and the return spring 160. The third piston 490 divides the first oil chamber 140 into a left chamber 500 and a right chamber 510. The return spring 160 is located in the right chamber 510. The two ends of the third piston 490 are respectively used to support the first piston 130 and the return spring 160. The third piston 490 is provided with a pressure reducing valve 520. The pressure reducing valve 520 is used for oil flow between the left chamber 500 and the right chamber 510. The pressure reducing valve 520 can reduce the pressure on the return spring 160.

[0062] It is understandable that when the door closer needs to automatically close the door after the door opening is completed, the elastic potential energy accumulated in the compressed return spring 160 is released, and the elastic force generated by the return spring 160 acts on the third piston 490 to push the third piston 490 to move and reset. At this time, the pressure reducing valve 520 on the third piston 490 can reduce the pressure on the return spring 160, so that the third piston 490 offsets part of the elastic force of the return spring 160 through the pressure reducing valve 520 and then pushes the first piston 130 to move and reset, thereby avoiding the return spring 160 directly acting on the first piston 130. As a result, the third piston 490 can reduce the pressure and buffer the return spring 160, reduce the impact force on the first piston 130, reduce the squeezing force of the first piston 130 on the drive shaft 110, reduce the risk of the first piston 130 pushing the drive shaft 110, and ensure the service life of the door closer.

[0063] In some specific embodiments, the pressure reducing valve 520 includes a second valve seat 530 and a second valve core 540, the second valve seat 530 is connected to the third piston 490, the second valve seat 530 has a first through hole 550, and the second valve core 540 has a pressure reducing hole 560 for oil passing. When the third piston 490 compresses the reset spring 160, the hydraulic oil in the housing 100 pushes the second valve core 540 away from the second valve seat 530 to open the first through hole 550 for oil passing. When the reset spring 160 pushes the third piston 490 to reset, the hydraulic oil in the housing 100 pushes the second valve core 540 toward the second valve seat 530 to close the first through hole 550.

[0064] It can be understood that during the door opening process, the third piston 490 compresses the return spring 160. At this time, the hydraulic oil can push the second valve core 540 away from the second valve seat 530 to open the first through hole 550, and the hydraulic oil can flow through the first through hole 550 and the pressure reducing hole 560 to ensure the oil flow area. During the door closing process, the compressed return spring 160 is reset, and the return spring 160 pushes the third piston 490 to reset. At this time, the hydraulic oil can push the second valve core 540 toward the second valve seat 530, so that the second valve core 540 closes the first through hole 550, so that the hydraulic oil can only flow through the pressure reducing hole 560, reducing the oil flow area of ​​the pressure reducing valve 520, reducing the moving speed of the third piston 490, so that the third piston 490 can offset part of the elastic force of the return spring 160, and then, the third piston 490 can decompress and buffer the return spring 160.

[0065] Furthermore, the second valve core 540 is also provided with a first filter plate 570 , and at least two first filter plates 570 are provided. The at least two first filter plates 570 are respectively arranged at both ends of the pressure reducing hole 560 , and the first filter plates 570 are used to block the splashing of hydraulic oil passing through the pressure reducing hole 560 .

[0066] It is understandable that since the diameter of the pressure reducing hole 560 is smaller than the cross-sectional area of ​​the inner cavity of the shell 100, when the hydraulic oil passes through the pressure reducing hole 560, the oil flow area is suddenly reduced, which will cause the flow rate of the hydraulic oil through the pressure reducing hole 560 to accelerate. By arranging the first filter plate 570 at both ends of the pressure reducing hole 560, the first filter plate 570 can block the hydraulic oil on the injection path of the hydraulic oil, thereby preventing the high-pressure sputtering of the hydraulic oil, and further, it is beneficial to reduce the pressure of the hydraulic oil after passing through the pressure reducing hole 560.

[0067] In some specific embodiments, the pressure reducing valve 520 also includes a first sleeve 580, which is slidably disposed in the first through hole 550, and the second valve core 540 includes a core 590 and a cover 600, the core 590 is connected to the inner wall of the first sleeve 580, and the cover 600 is used to cover and seal the first through hole 550, and a third oil channel connecting the two ends of the first through hole 550 is provided between the outer wall of the first sleeve 580 and the inner wall of the first through hole 550.

[0068] It can be understood that the first sleeve 580 is slidably set in the first through hole 550, and the core 590 of the second valve core 540 is connected to the inner wall of the first sleeve 580, so that the first through hole 550 can limit and guide the sliding of the first sleeve 580, thereby making the action of the second valve core 540 opening and closing the first through hole 550 smoother.

[0069] Furthermore, the cross-section of the outer wall of the first sleeve 580 is polygonal, and the gap between the outer wall of the first sleeve 580 and the inner wall of the first through hole 550 forms a third oil channel, so that a part of the outer wall of the first sleeve 580 slides in contact with the inner wall of the first through hole 550, and a part of the outer wall of the first sleeve 580 has a gap with the inner wall of the first through hole 550, thereby preventing the first sleeve 580 from completely blocking the first through hole 550, thereby facilitating the formation of the third oil channel.

[0070] In some specific embodiments, the pressure reducing valve 520 also includes an externally toothed washer 610 and a locking screw 620. The externally toothed washer 610 is arranged at one end of the first sleeve 580 away from the second valve core 540. The externally toothed washer 610 has a tooth portion, which abuts against the second valve seat 530 for limiting position. The locking screw 620 is threadedly connected to the first sleeve 580 to fix the externally toothed washer 610 at the end of the first sleeve 580.

[0071] It can be understood that when the door is opened, the third piston 490 compresses the return spring 160. When the hydraulic oil passes through the pressure reducing valve 520, the hydraulic oil pushes the second valve core 540 away from the second valve seat 530. At this time, the first sleeve 580 moves in the direction close to the valve core, so that the first sleeve 580 can drive the external tooth washer 610 to approach the second valve seat 530. When the tooth portion of the external tooth washer 610 abuts against the second valve seat 530, the movement of the first slide seat can be limited to prevent the first sleeve 580 from disengaging from the first through hole 550. At the same time, after the tooth portion of the external tooth washer 610 abuts against the second valve seat 530, there is a gap between the tooth portion and the second valve seat 530 to prevent the external tooth washer 610 from blocking the first through hole 550.

[0072] In some specific embodiments, a U-shaped sealing ring 630 is sleeved on the third piston 490 , and the U-shaped sealing ring 630 abuts against and seals against the inner wall of the housing 100 , thereby facilitating the sealing between the third piston 490 and the inner wall of the housing 100 .

[0073] As for the one-way valve 170, the one-way valve 170 is arranged on the first piston 130, and the one-way valve 170 accommodates the hydraulic oil flowing from the first oil chamber 140 to the second oil chamber 150. The side wall of the housing 100 is provided with a first oil channel 180, and the first oil channel 180 connects the first oil chamber 140 and the second oil chamber 150. The side wall of the second oil chamber 150 is formed with two first oil ports 190, and the two first oil ports 190 are arranged in sequence along the moving direction of the first piston 130, and the two first oil ports 190 are both connected to the first oil channel 180.

[0074] It can be understood that when the door closer drives the door leaf to close, the return spring 160 drives the first piston 130 to move toward the second oil chamber 150, and the hydraulic oil in the second oil chamber 150 is squeezed by the first piston 130, so that the hydraulic oil in the second oil chamber 150 enters the first oil passage 180 from the first oil port 190 and flows to the first oil chamber 140. During the movement of the first piston 130, the two first oil ports 190 are unobstructed at the beginning, and the hydraulic oil in the second oil chamber 150 can enter the first oil passage 180 from the two first oil ports 190, so that the door closer can The door leaf is driven to close at high speed in the front closing angle range, thereby allowing the door leaf to swing quickly to close in the front closing angle range, thereby improving the closing efficiency of the door leaf. When the first piston 130 continues to move and blocks a first oil port 190, the hydraulic oil in the second oil chamber 150 can only enter the first oil channel 180 from one first oil port 190, so that the door closer can drive the door leaf to close at low speed in the middle closing angle range, thereby allowing the door leaf to swing at low speed before entering the door frame, thereby preventing the door leaf from closing too quickly and causing the door leaf to pinch people at the door frame, thereby improving safety.

[0075] In some specific embodiments, the shell 100 is threadedly connected to two second valve needles 410, and the two second valve needles 410 are respectively used to adjust the openings of the two first oil ports 190 to adjust the oil flow speed of the two first oil ports 190. Thus, by respectively adjusting the openings of the two first oil ports 190 through the two second valve needles 410, the closing swing speeds of the door leaf in the front closing angle range and the middle closing angle range can be adjusted respectively, thereby making the closing swing speed of the door leaf driven by the door closer adjustable.

[0076] In some specific embodiments, the one-way valve 170 has a safety valve hole 640, a safety valve ball 650 and a safety valve spring 660. The safety valve hole 640 connects the first oil chamber 140 and the second oil chamber 150. One end of the safety valve spring 660 abuts against the one-way valve 170, and the other end of the safety valve spring 660 abuts against the safety valve ball 650. The safety valve spring 660 is used to drive the safety valve core from one end of the safety valve hole 640 close to the first oil chamber 140 to block the safety valve hole 640.

[0077] It can be understood that in the closed door state, when in the normal state, the elastic force of the safety valve spring 660 on the safety valve ball 650 is greater than the oil pressure in the second oil chamber 150, and the safety valve spring 660 can drive the safety valve ball 650 to continuously block the safety valve hole 640, so that the safety valve hole 640 is normally closed. When the first oil channel 180 is blocked or the door leaf is interfered by external force and the oil pressure in the second oil chamber 150 is too high, the hydraulic oil pressure in the second oil chamber 150 exceeds the elastic force of the safety valve spring 660, and the hydraulic oil in the second oil chamber 150 can propel the safety valve ball 650 to open the safety valve hole 640, thereby allowing the hydraulic oil in the second oil chamber 150 to flow from the safety valve hole 640 to the first oil chamber 140, thereby facilitating the pressure relief of the second oil chamber 150 and preventing the hydraulic oil pressure in the second oil chamber 150 from being too high and damaging the door closer.

[0078] Reference Figure 4 For the speed control valve 200, the speed control valve 200 includes a first valve body 210, a second piston 220, a first spring 230, a first valve core 240 and a second spring 250. The first valve body 210 is arranged at one end of the second oil chamber 150 away from the first oil chamber 140, and the second piston 220 is slidably arranged in the first valve body 210. The first spring 230 is used to drive the second piston 220 to approach the first piston 130.

[0079] Reference Figure 5 As for the second oil passage 260, the second oil passage 260 passes through the side wall of the shell 100, the first valve body 210 and the second piston 220 in sequence, connecting the first oil chamber 140 and the second oil chamber 150. The first valve core 240 is slidably arranged in the second piston 220. The second spring 250 is used to drive the first valve core 240 to seal the second oil passage 260. The first piston 130 moves and resets to push the first valve core 240 to open the first oil passage 180.

[0080] In this embodiment, a speed regulating valve 200 and a second oil passage 260 are provided. The speed regulating valve 200 includes a first valve body 210, a second piston 220, a first spring 230, a first valve core 240 and a second spring 250. The first valve body 210 is provided at an end of the second oil chamber 150 away from the first oil chamber 140, the second piston 220 is slidably provided in the first valve body 210, and the first spring 230 is used to drive the second piston 220 to approach the first piston 130; the second oil passage 260 passes through the side wall of the housing 100, the first valve body 210 and the second piston 220 in sequence, and connects the first oil chamber 140 and the second oil chamber 150. The first valve core 240 is slidably provided in the second piston 220, and the second spring 250 is used to drive the first valve core 240 to seal The second oil passage 260, the first piston 130 moves and resets to push the first valve core 240 to open the first oil passage 180. It can be understood that in the rear closing angle range when the door closer drives the door leaf to close the door, the first piston 130 pushes the first valve core 240 to open the first oil passage 180, and then pushes the second piston 220 to move, so that the hydraulic oil in the second oil chamber 150 can synchronously flow to the first oil chamber 140 through the second oil passage 260, thereby increasing the return oil speed from the second oil chamber 150 to the first oil chamber 140, so that the door closer can increase the swing speed of the door leaf in the rear closing angle range when driving the door leaf to close the door, and then, the door leaf swings highly after entering the door frame, so that the door leaf can be locked at a sufficient speed, thereby ensuring that the door leaf can be locked smoothly.

[0081] In this embodiment, a first spring 230 is provided, and the first spring 230 is used to drive the second piston 220 to approach the first piston 130. Therefore, when the first piston 130 releases the second piston 220, the first spring 230 can drive the second piston 220 to restore its position, thereby ensuring the normal use of the second piston 220 when the door is closed next time.

[0082] In this embodiment, a second spring 250 is provided, and the second spring 250 is used to drive the first valve core 240 to seal the second oil channel 260. Therefore, when the first piston 130 releases the first valve core 240, the second spring 250 can drive the first valve core 240 to restore the sealing of the second oil channel 260, thereby preventing the hydraulic oil in the first oil chamber 140 from flowing back from the second oil channel 260 to the second oil chamber 150. At the same time, it ensures that the second oil channel 260 can normally perform the function of increasing the swing speed of the door leaf in the rear closing angle range when the door is closed next time.

[0083] In some specific embodiments, the first piston 130 abuts against the first valve core 240 and the second piston 220 via the one-way valve 170 .

[0084] In some specific embodiments, the side wall of the first valve body 210 has a first hole 270, which is used to form a part of the second oil channel 260. The outer peripheral wall of the second piston 220 is provided with a first annular groove 280, which is used to form a part of the second oil channel 260. The first annular groove 280 is connected to the orifice of the first hole 270, and the groove width of the first annular groove 280 along the sliding direction of the second piston 220 is greater than the orifice diameter of the first hole 270.

[0085] It is understandable that during the closing process of the door leaf, the first piston 130 will push the second piston 220 to move. By making the groove width of the first annular groove 280 along the sliding direction of the second piston 220 larger than the orifice diameter of the first hole 270, the first annular groove 280 can remain connected with the first hole 270 during the movement of the second piston 220, thereby avoiding the misalignment of the first annular groove 280 and the orifice of the first hole 270, which will cause the second oil channel 260 to be unable to pass oil, and further, ensuring that the second oil channel 260 can remain unobstructed during the movement of the second piston 220.

[0086] In some specific embodiments, the side wall of the first valve body 210 has a first hole 270, and the first hole 270 is used to form a part of the second oil channel 260. The first valve body 210 is threadedly connected with a first valve needle 290, and the first valve needle 290 is used to adjust the opening of the first hole 270 to adjust the oil flow speed of the second oil channel 260. Thus, the closing swing speed of the door leaf can be adjusted by adjusting the oil flow speed of the second oil channel 260, and then, the closing swing speed of the door leaf driven by the door closer can be adjusted.

[0087] In some specific embodiments, the second piston 220 is provided with a T-shaped hole 300, which is used to form a part of the second oil channel 260. The small-diameter port of the T-shaped hole 300 is connected to the second oil chamber 150. The first valve core 240 is configured as a T-shaped needle. The T-shaped hole 300 accommodates the sliding of the first valve core 240. When the second spring 250 squeezes the first valve core 240 to seal the T-shaped hole 300, the end of the first valve core 240 protrudes out of the small-diameter port of the T-shaped hole 300.

[0088] It can be understood that by arranging a T-hole 300 in the second piston 220 to cooperate with the first valve core 240, the T-hole 300 can limit the first valve core 240 to prevent the second spring 250 from completely squeezing the first valve core 240 out of the second piston 220. At the same time, when the second spring 250 squeezes the first valve core 240 to seal the T-hole 300, the end of the first valve core 240 protrudes out of the small-diameter port of the T-hole 300, so that the first piston 130 can first push the end of the first valve core 240 to open the T-hole 300 and then push the second piston 220 to move, thereby allowing the second oil channel 260 to keep oil flowing during the process of the first piston 130 pushing the second piston 220 to move.

[0089] Furthermore, the first valve core 240 includes a large diameter needle segment 310 and a small diameter needle segment 320, and the T-shaped hole 300 includes a large diameter hole segment 330 and a small diameter hole segment 340. The small diameter needle segment 320 and the small diameter hole segment 340 are clearance-matched. The cross-section of the outer peripheral surface of the large diameter needle segment 310 is polygonal. The edges and corners of the outer peripheral surface of the large diameter needle segment 310 are slidingly matched with the large diameter hole segment 330. The plane of the outer peripheral surface of the large diameter needle segment 310 is clearance-matched with the large diameter hole segment 330. The end face of the large diameter needle segment 310 close to the small diameter needle segment 320 abuts against the end face of the small diameter hole segment 340 to seal the T-shaped hole 300.

[0090] It can be understood that by making the cross-section of the outer circumferential surface of the large-diameter needle segment 310 polygonal, the edges and corners of the outer circumferential surface of the large-diameter needle segment 310 slidingly fit with the large-diameter hole segment 330, and the plane of the outer circumferential surface of the large-diameter needle segment 310 gap-fitting with the large-diameter hole segment 330, the outer circumferential surface of the large-diameter needle segment 310 can slide with the large-diameter hole segment 330 while ensuring that there is a gap between the outer circumferential surface of the large-diameter needle segment 310 and the large-diameter hole segment 330 to accommodate the passage of hydraulic oil, thereby, the gap between the outer circumferential surface of the large-diameter needle segment 310 and the large-diameter hole segment 330 and the gap between the small-diameter needle segment 320 and the small-diameter hole segment 340 can form a part of the second oil channel 260.

[0091] In some specific embodiments, the speed control valve 200 also includes an adjusting needle 350, which is threadedly connected to the side wall of the first valve body 210, and the adjusting needle 350 has a reducing section 360. The second piston 220 has an adjusting groove 370 arranged along the radial direction of the second piston 220. The reducing section 360 and the adjusting groove 370 are clearance-matched, and the reducing section 360 and the adjusting groove 370 are clearance-matched. The adjusting needle 350 is used to adjust the position of the second piston 220 in the second oil chamber 150.

[0092] It can be understood that by adjusting the depth of the adjusting needle 350 in the first valve body 210, the positions of different diameters of the reducing section 360 can be matched with the adjusting groove 370, thereby adjusting the movable range of the second piston 220 and the position of the second piston 220 in the second oil chamber 150, thereby facilitating the change of the door leaf angle position of the door closer starting speed regulating valve 200.

[0093] Furthermore, the distance adjusting slot 370 has an inclined wall mouth 380, and the inclination of the inclined wall mouth 380 is consistent with the inclination of the variable diameter section 360. Therefore, when the variable diameter section 360 and the distance adjusting slot 370 are abutted and limited, the inclined wall mouth 380 can fit with one side of the variable diameter section 360, thereby making the cooperation between the variable diameter section 360 and the distance adjusting slot 370 more stable.

[0094] In some specific embodiments, the distance adjusting groove 370 passes through the second piston 220, and the side wall of the first valve body 210 is further provided with a limiting hole 390. One end of the distance adjusting needle 350 passes through the distance adjusting groove 370 and cooperates with the limiting hole 390 to limit the position, thereby making the support of the first valve body 210 to the distance adjusting needle 350 more stable, and further, making the limiting of the second piston 220 by the distance adjusting needle 350 more stable.

[0095] In some specific embodiments, a third spring 400 is provided in the limiting hole 390, and two ends of the second spring 250 respectively abut against the bottom wall of the limiting hole 390 and the end of the distance adjusting needle 350, and the third spring 400 supports the distance adjusting needle 350 to press the distance adjusting needle 350, so that the third spring 400 supports the distance adjusting needle 350, so that the distance adjusting needle 350 will not be loosened due to the gap of the threaded fit between the distance adjusting needle 350 and the first valve body 210, thereby making the distance adjusting needle 350 more stable.

[0096] In the description of this specification, the description with reference to the terms "one embodiment, some embodiments, illustrative embodiments, examples, specific examples or some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0097] The terms "first, second, third, fourth", etc. (if any) in the specification and claims of this application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that shown or described herein.

[0098] It should also be noted that in the description of this specification, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0099] In addition, the terms "comprises" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may also include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0100] Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0101] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A door closer, characterized in that: include: Housing (100); A transmission shaft (110) rotatably disposed on the housing (100) and having a cam (120); A first piston (130) is slidably disposed in the housing (100), dividing the inner cavity of the housing (100) into a first oil cavity (140) and a second oil cavity (150), and is in abutment with the cam (120) for transmission; A return spring (160) is located in the first oil chamber (140) and is used to push the first piston (130) to move toward the second oil chamber (150) to return to its original position so as to drive the door leaf to close; a one-way valve (170) disposed on the first piston (130) and accommodating hydraulic oil flowing from the first oil chamber (140) to the second oil chamber (150); a first oil passage (180) is disposed on the side wall of the housing (100); the first oil passage (180) is connected to the first oil chamber (140) and the second oil chamber (150); two first oil ports (190) are formed on the side wall of the second oil chamber (150); the two first oil ports (190) are arranged in sequence along the moving direction of the first piston (130); and the two first oil ports (190) are both connected to the first oil passage (180); A speed regulating valve (200), comprising a first valve body (210), a second piston (220), a first spring (230), a first valve core (240) and a second spring (250), wherein the first valve body (210) is arranged at an end of the second oil chamber (150) away from the first oil chamber (140), the second piston (220) is slidably arranged in the first valve body (210), and the first spring (230) is used to drive the second piston (220) to approach the first piston (130); The second oil passage (260) passes through the side wall of the housing (100), the first valve body (210) and the second piston (220) in sequence, and is connected to the first oil chamber (140) and the second oil chamber (150). The first valve core (240) is slidably arranged in the second piston (220). The second spring (250) is used to drive the first valve core (240) to seal the second oil passage (260). The first piston (130) moves and resets to push the first valve core (240) to open the first oil passage (180).

2. A door closer according to claim 1, characterized in that: The side wall of the first valve body (210) has a first hole (270), and the first hole (270) is used to form a part of the second oil channel (260). The outer peripheral wall of the second piston (220) is provided with a first annular groove (280), and the first annular groove (280) is used to form a part of the second oil channel (260). The first annular groove (280) is connected to the orifice of the first hole (270), and the groove width of the first annular groove (280) along the sliding direction of the second piston (220) is greater than the orifice diameter of the first hole (270).

3. A door closer according to claim 1, characterized in that: The side wall of the first valve body (210) has a first hole (270), and the first hole (270) is used to form a part of the second oil channel (260). The first valve body (210) is threadedly connected with a first valve needle (290), and the first valve needle (290) is used to adjust the opening of the first hole (270) to adjust the oil flow rate of the second oil channel (260).

4. A door closer according to claim 1, characterized in that: The second piston (220) is provided with a T-shaped hole (300), and the T-shaped hole (300) is used to form a part of the second oil channel (260). The small-diameter port of the T-shaped hole (300) is connected to the second oil chamber (150). The first valve core (240) is configured as a T-shaped needle. The T-shaped hole (300) accommodates the sliding of the first valve core (240). When the second spring (250) squeezes the first valve core (240) to seal the T-shaped hole (300), the end of the first valve core (240) protrudes outside the small-diameter port of the T-shaped hole (300).

5. A door closer according to claim 4, characterized in that: The first valve core (240) comprises a large-diameter needle segment (310) and a small-diameter needle segment (320); the T-shaped hole (300) comprises a large-diameter hole segment (330) and a small-diameter hole segment (340); the small-diameter needle segment (320) is clearance-matched with the small-diameter hole segment (340); the cross-section of the outer peripheral surface of the large-diameter needle segment (310) is polygonal; the edges and corners of the outer peripheral surface of the large-diameter needle segment (310) are slidingly matched with the large-diameter hole segment (330); the plane of the outer peripheral surface of the large-diameter needle segment (310) is clearance-matched with the large-diameter hole segment (330); the end surface of the large-diameter needle segment (310) close to the small-diameter needle segment (320) abuts against the end surface of the small-diameter hole segment (340) to seal the T-shaped hole (300).

6. A door closer according to claim 1, characterized in that: The speed regulating valve (200) further comprises a distance regulating needle (350), the distance regulating needle (350) being threadedly connected to the side wall of the first valve body (210), the distance regulating needle (350) having a diameter reducing section (360), the second piston (220) having a distance regulating groove (370) arranged along the radial direction of the second piston (220), the diameter reducing section (360) being clearance-matched with the distance regulating groove (370), the diameter reducing section (360) being clearance-matched with the distance regulating groove (370), and the distance regulating needle (350) being used to adjust the position of the second piston (220) in the second oil chamber (150).

7. A door closer according to claim 6, characterized in that: The distance adjustment groove (370) has an inclined wall opening (380), and the inclination of the inclined wall opening (380) is consistent with the inclination of the diameter-changing section (360).

8. A door closer according to claim 6, characterized in that: The distance adjustment groove (370) passes through the second piston (220), and a limiting hole (390) is further provided on the side wall of the first valve body (210). One end of the distance adjustment needle (350) passes through the distance adjustment groove (370) and cooperates with the limiting hole (390) to limit the position.

9. A door closer according to claim 8, characterized in that: A third spring (400) is arranged in the limiting hole (390), two ends of the second spring (250) respectively abut against the bottom wall of the limiting hole (390) and the end of the distance adjustment needle (350), and the third spring (400) supports the distance adjustment needle (350) to press the distance adjustment needle (350).

10. The door closer according to claim 1, characterized in that: The housing (100) is threadedly connected to two second valve needles (410), and the two second valve needles (410) are respectively used to adjust the opening of the two first oil ports (190) to adjust the oil flow speed of the two first oil ports (190).

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