A door closer

Abstract

The application discloses a door closer, which comprises a shell, a transmission shaft with a cam, a first piston for dividing an inner cavity of the shell into a first oil cavity and a second oil cavity and abutting against the cam for transmission, a reset spring for pushing the first piston to move to the second oil cavity for resetting and driving a door leaf to close, a one-way valve arranged on the first piston and containing hydraulic oil flowing from the first oil cavity to the second oil cavity, a first oil channel arranged on a side wall of the shell and communicating the first oil cavity and the second oil cavity, two first oil ports formed in a side wall of the second oil cavity, a speed regulating valve comprising a first valve body, a second piston, a first spring, a first valve core and a second spring, a second oil channel communicating the first oil cavity and the second oil cavity, the second spring for sealing the second oil channel by driving the first valve core, and the first piston moving to reset and pushing the first valve core to open the first oil channel. The door closer can realize three-stage speed closing and balance closing efficiency, safety and smooth locking.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of door closers, in particular to a door closer. BACKGROUND

[0002] A door closer is a mechanism that automatically closes a door. It is a hydraulic device on the door head that can automatically close the door by releasing the compression after the door is opened, which has the function of a spring door. It can ensure that the door is accurately and timely closed to the initial position after being opened.

[0003] In related technologies, 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. One end of the return spring abuts against the inner wall of the end of the housing, and the other end of the return spring 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] The existing door closer usually closes the door at a constant speed or at two levels of speed when automatically closing the door.

[0006] For constant-speed closing, the door leaf maintains a constant closing speed during the automatic closing process of the door closer.

[0007] For two-level-speed closing, the door leaf can close at different speeds in two door closing angle intervals. It can close at a low speed in the front angle interval and at a high speed in the rear angle interval, or it can close at a high speed in the front angle interval and at a low speed in the rear angle interval.

[0008] However, for constant-speed closing, if the closing speed is too fast, the door leaf is easy to pinch people at the door frame, and the safety is poor. If the closing speed is too slow, the closing time is long, and the closing efficiency is poor. For two-level-speed closing, if the door leaf closes at a low speed in the front angle interval and at a high speed in the rear angle interval, the door leaf closing efficiency is low and the door leaf is easy to pinch people at the door frame, and the safety is poor. If the door leaf closes at a high speed in the front angle interval and at a low speed in the rear angle interval, the door closer may not be strong enough to close the door leaf smoothly, so the existing door closer is difficult to balance the closing efficiency, safety, and smooth closing. SUMMARY

[0009] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a door closer that can achieve three-level-speed closing and balance the closing efficiency, safety, and smooth closing.

[0010] According to the door closer of the embodiment of the present application, the door closer comprises:

[0011] a housing;

[0012] a transmission shaft rotatably arranged on the housing and having a cam;

[0013] a first piston slidably arranged in the housing and dividing an inner cavity of the housing into a first oil cavity and a second oil cavity and abuttingly transmitting with the cam;

[0014] a reset spring arranged in the first oil cavity and used for pushing the first piston to move to the second oil cavity to reset and drive a door leaf to close;

[0015] a one-way valve 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 arranged on a side wall of the housing and communicating the first oil cavity and the second oil cavity, and two first oil ports formed on a side wall of the second oil cavity and arranged in sequence along a moving direction of the first piston and each communicating the first oil channel;

[0016] a speed regulating valve including a first valve body, a second piston, a first spring, a first valve core and a second spring, the first valve body being arranged at an end of the second oil cavity away from the first oil cavity, the second piston being slidably arranged in the first valve body, and the first spring being used for driving the second piston to be close to the first piston;

[0017] a second oil channel penetrating the side wall of the housing, the first valve body and the second piston in sequence and communicating the first oil cavity and the second oil cavity, the first valve core being slidably arranged in the second piston, and the second spring being used for driving the first valve core to seal the second oil channel, and the first piston moving to reset to push the first valve core to open the first oil channel.

[0018] The door closer has at least the following beneficial effects:

[0019] 1. The door closer has the effects that the reset spring is arranged to push the first piston to move to the second oil cavity to reset and drive the door leaf to close, so that the door closer can automatically drive the door leaf to close.

[0020] 2. The application sets a one-way valve, the one-way valve is arranged on the first piston, the one-way valve contains hydraulic oil from the first oil cavity to the second oil cavity, the side wall of the shell is provided with a first oil channel, the first oil channel is communicated with the first oil cavity and the second oil cavity, the side wall of the second oil cavity is formed with two first oil ports, the two first oil ports are arranged in sequence along the moving direction of the first piston, and the two first oil ports are communicated with the first oil channel. It can be understood that when the door closer drives the door leaf to close the door, the reset spring drives the first piston to move towards the second oil cavity, the hydraulic oil in the second oil cavity is extruded by the first piston, so that the hydraulic oil in the second oil cavity flows from the first oil port to the first oil channel to the first oil cavity. In the moving process of the first piston, at the beginning, the two first oil ports are unobstructed, and the hydraulic oil in the second oil cavity can enter the first oil channel from the two first oil ports, so that the door closer can drive the door leaf to close the door at a high speed in the front door closing angle interval, so that the door leaf can be quickly swung to close the door in the front door closing angle interval, and the door closing efficiency is improved. When the first piston continues to move and blocks one first oil port, the hydraulic oil in the second oil cavity can only enter the first oil channel from one first oil port, so that the door closer can drive the door leaf to close the door at a low speed in the middle door closing angle interval, so that the door leaf can swing at a low speed before entering the door frame, avoiding the door leaf from being injured at the door frame due to too fast closing speed, and improving the safety.

[0021] 3. The application sets a speed regulating valve and a second oil channel, the speed regulating valve comprises a first valve body, a second piston, a first spring, a first valve core and a second spring, the first valve body is arranged at one end of the second oil cavity away from the first oil cavity, the second piston is slidably arranged in the first valve body, and the first spring is used to drive the second piston to be close to the first piston. The second oil channel penetrates the side wall of the shell, the first valve body and the second piston in sequence, and is communicated with the first oil cavity and the second oil cavity. The first valve core is slidably arranged in the second piston, and the second spring is used to drive the first valve core to seal the second oil channel. The first piston moves to reset to push the first valve core to open the first oil channel. It can be understood that in the rear door closing angle interval 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 cavity can flow to the first oil cavity through the second oil channel simultaneously, thereby improving the oil return speed of the second oil cavity to the first oil cavity, so that the door closer can improve the swing speed of the door leaf in the rear door closing angle interval when driving the door leaf to close the door, and then the door leaf swings at a high speed after entering the door frame, so that the door leaf can have enough speed to lock, and the door leaf can be smoothly locked.

[0022] 4. The application sets a first spring, which is used to drive the second piston to be close to the first piston, so that after the first piston releases the second piston, the first spring can drive the second piston to recover the position, and then the normal use of the second piston in the next door closing can be ensured.

[0023] 5. The application sets a second spring, which is used to drive the first valve core to seal the second oil channel, so that when the first piston releases the first valve core, the second spring can drive the first valve core to recover the sealing of the second oil channel, avoiding the hydraulic oil in the first oil cavity from flowing back to the second oil cavity through the second oil channel, and at the same time, ensuring that the second oil channel can normally play the function of improving the swing speed of the door leaf in the next door closing angle interval.

[0024] According to some embodiments of the application, the side wall of the first valve body has a first hole for forming a part of the second oil channel, and the outer peripheral wall of the second piston is provided with a first annular groove for forming a part of the second oil channel, and the first annular groove is communicated with the hole opening 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 hole opening diameter of the first hole.

[0025] Beneficially, the application has a first hole in the side wall of the first valve body, which is used to form a part of the second oil channel, and 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, and the first annular groove is communicated with the hole opening 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 hole opening 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 hole opening diameter of the first hole, the first annular groove can be kept in communication with the first hole during the movement of the second piston, avoiding the misalignment of the first annular groove and the hole opening of the first hole, which causes the second oil channel to be unable to pass oil, and thus ensuring that the second oil channel can remain unobstructed during the movement of the second piston.

[0026] According to some embodiments of the application, the side wall of the first valve body has a first hole for forming a part of the second oil channel, and the first valve body is threadedly connected with a first valve needle for adjusting the opening degree of the first hole to adjust the oil passing speed of the second oil channel.

[0027] Beneficially, the application has a first hole in the side wall of the first valve body, which is used to form a part of the second oil channel, and the first valve body is threadedly connected with a first valve needle for adjusting the opening degree of the first hole to adjust the oil passing speed of the second oil channel, so that by adjusting the oil passing speed of the second oil channel, the closing swing speed of the door leaf can be adjusted, and thus the closing swing speed of the door leaf driven by the door closer can be adjusted.

[0028] According to some embodiments of the present application, the second piston is provided with a T-shaped hole for forming a part of the second oil passage, a small-diameter port of the T-shaped hole being communicated with the second oil cavity, the first valve core is provided as a T-shaped needle, the T-shaped hole contains the first valve core to slide, and when the second spring extrudes the first valve core to seal the T-shaped hole, an end of the first valve core protrudes out of the small-diameter port of the T-shaped hole.

[0029] Beneficially, according to some embodiments of the present application, the second piston is provided with a T-shaped hole for forming a part of the second oil passage, a small-diameter port of the T-shaped hole being communicated with the second oil cavity, the first valve core is provided as a T-shaped needle, the T-shaped hole contains the first valve core to slide, and when the second spring extrudes the first valve core to seal the T-shaped hole, an end of the first valve core protrudes out of the small-diameter port of the T-shaped hole. It can be understood that, by providing the T-shaped hole in the second piston and cooperating with the first valve core, the T-shaped hole can limit the first valve core, avoiding the second spring from extruding the first valve core out of the second piston completely, and at the same time, when the second spring extrudes 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, so that the first piston can first push the end of the first valve core to open the T-shaped hole and then push the second piston to move, and further, the second oil passage can keep oil flowing during the movement of the first piston.

[0030] According to some embodiments of the present application, the first valve core comprises a large-diameter needle segment and a small-diameter needle segment, the T-shaped hole comprises a large-diameter hole segment and a small-diameter hole segment, the small-diameter needle segment is in clearance fit with the small-diameter hole segment, a cross section of an outer periphery surface of the large-diameter needle segment is polygonal, an edge of the outer periphery surface of the large-diameter needle segment is in sliding fit with the large-diameter hole segment, a flat surface of the outer periphery surface of the large-diameter needle segment is in clearance fit with the large-diameter hole segment, and an end surface of the large-diameter needle segment close to the small-diameter needle segment is in abutment with an end surface of the small-diameter hole segment to seal the T-shaped hole.

[0031] Beneficially, according to some embodiments of the present application, the first valve core comprises a large-diameter needle segment and a small-diameter needle segment, the T-shaped hole comprises a large-diameter hole segment and a small-diameter hole segment, the small-diameter needle segment is in clearance fit with the small-diameter hole segment, a cross section of an outer periphery surface of the large-diameter needle segment is polygonal, an edge of the outer periphery surface of the large-diameter needle segment is in sliding fit with the large-diameter hole segment, a flat surface of the outer periphery surface of the large-diameter needle segment is in clearance fit with the large-diameter hole segment, and an end surface of the large-diameter needle segment close to the small-diameter needle segment is in abutment with an end surface of the small-diameter hole segment to seal the T-shaped hole. It can be understood that, by making the cross section of the outer periphery surface of the large-diameter needle segment be polygonal, the edge of the outer periphery surface of the large-diameter needle segment be in sliding fit with the large-diameter hole segment, and the flat surface of the outer periphery surface of the large-diameter needle segment be in clearance fit with the large-diameter hole segment, the outer periphery surface of the large-diameter needle segment can be in sliding fit with the large-diameter hole segment while ensuring that there is clearance between the outer periphery surface of the large-diameter needle segment and the large-diameter hole segment for hydraulic oil to pass through, so that the clearance between the outer periphery surface of the large-diameter needle segment and the large-diameter hole segment and the clearance between the small-diameter needle segment and the small-diameter hole segment can form a part of the second oil passage.

[0032] According to some embodiments of the present invention, the speed control valve further includes an adjusting pin, which is threadedly connected to the side wall of the first valve body. The adjusting pin has a variable diameter section, and the second piston has an adjusting groove arranged radially along the second piston. The variable diameter section is in clearance fit with the adjusting groove, and the adjusting pin is used to adjust the position of the second piston in the second oil chamber.

[0033] Advantages: This invention includes an adjusting pin in the speed control valve. The adjusting pin is threaded to the side wall of the first valve body. The adjusting pin has a variable diameter section. The second piston has an adjusting groove arranged radially along the second piston. The variable diameter section and the adjusting groove are in clearance fit. The adjusting pin 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 pin in the first valve body, the positions of different diameters of the variable diameter section can be matched with the adjusting groove. Thus, the movable range of the second piston can be adjusted, and the position of the second piston in the second oil chamber can be adjusted. In addition, it is convenient to change the door leaf angle position of the door closer starting the speed control valve.

[0034] According to some embodiments of the present invention, the adjusting groove has an inclined wall opening, the inclination of which is consistent with the inclination of the variable diameter section.

[0035] The advantage of this invention is that by giving the adjusting groove a sloping opening, the slope of which is consistent with the slope of the variable diameter section, the sloping opening can fit against one side of the variable diameter section when the variable diameter section comes into contact with the adjusting groove, thereby making the fit between the variable diameter section and the adjusting groove smoother.

[0036] According to some embodiments of the present invention, the adjusting groove passes through the second piston, and the side wall of the first valve body is also provided with a limiting hole, and one end of the adjusting needle passes through the adjusting groove and cooperates with the limiting hole for limiting.

[0037] The advantage of this invention is that by having the adjusting groove pass through the second piston, and by providing a limiting hole on the side wall of the first valve body, one end of the adjusting needle passes through the adjusting groove and cooperates with the limiting hole to limit its position. This makes the support of the adjusting needle by the first valve body more stable, and consequently, makes the limiting of the adjusting needle by the second piston more stable.

[0038] According to some embodiments of the present invention, a third spring is provided 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 adjusting pin, and the third spring supports the adjusting pin to press the adjusting pin.

[0039] Beneficially, the third spring supports the distance adjusting needle to press the distance adjusting needle, so that the third spring supports the distance adjusting needle, so that the distance adjusting needle will not be loose due to the gap of the threaded cooperation between the distance adjusting needle and the first valve body, and in turn, the distance adjusting needle is more stable.

[0040] According to some embodiments of the present application, the housing is threadedly connected with two second valve needles, and the two second valve needles are respectively used for adjusting the opening degree of the two first oil ports to adjust the oil passing speed of the two first oil ports.

[0041] Beneficially, the housing is threadedly connected with two second valve needles, and the two second valve needles are respectively used for adjusting the opening degree of the two first oil ports to adjust the oil passing speed of the two first oil ports, so that the opening degree of the two first oil ports is respectively adjusted by the two second valve needles, the door leaf swing speed in the front door closing angle interval and the middle door closing angle interval is respectively adjusted, and in turn, the door closing swing speed driven by the door closer is adjustable.

[0042] Additional aspects and advantages of the present application will be given, partially in the following description, partially become obvious from the following description, or be understood by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0044] Figure 1 It is a structure schematic diagram of a door closer according to an embodiment of the present application;

[0045] Figure 2 It is a structure schematic diagram of a door closer according to an embodiment of the present application; Figure 1 It is a structure schematic diagram of a cam cooperating with a first piston;

[0046] Figure 3 It is a structure schematic diagram of a door closer according to an embodiment of the present application; Figure 1 It is an enlarged view of A shown;

[0047] Figure 4 It is an enlarged view of B shown; Figure 1 It is an enlarged view of B shown;

[0048] Figure 5 It is an enlarged view of B shown; Figure 1 It is a C-C sectional view shown.

[0049] 100 - housing, 110 - transmission shaft, 120 - cam, 130 - first piston, 140 - first oil cavity, 150 - second oil cavity, 160 - return spring, 170 - one-way valve, 180 - first oil passage, 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 passage, 270 - first hole, 280 - first ring groove, 290 - first valve needle, 300 - T-shaped hole, 310 - large-diameter needle segment, 320 - small-diameter needle segment, 330 - large-diameter hole segment, 340 - small-diameter hole segment, 350 - distance-adjusting needle, 360 - variable-diameter segment, 370 - distance-adjusting groove, 380 - inclined wall port, 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 relief valve, 530 - second valve seat, 540 - second valve core, 550 - first through hole, 560 - pressure relief hole, 570 - first filter piece, 580 - first sliding sleeve, 590 - core portion, 600 - cover portion, 610 - outer tooth washer, 620 - locking screw, 630 - U-shaped sealing ring, 640 - safety valve hole, 650 - safety valve bead, 660 - safety valve spring. DETAILED DESCRIPTION

[0050] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters throughout the figures denote the same or like elements or components. The embodiments described below are exemplary, and are not intended to be limiting of the present application.

[0051] In the description of the present application, it is to be understood that the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0052] In the description of the present application, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If it is described as first and second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0053] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting, connecting and connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0054] The accompanying drawings are referred to in the description of the present application. Figures 1-5 A door closer according to an embodiment of the present application is described.

[0055] The present application aims to provide an embodiment of a door closer.

[0056] Referring to Figure 1 In this embodiment, a door closer mainly comprises 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.

[0057] In terms of 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.

[0058] For the transmission shaft 110, the transmission shaft 110 is rotatably arranged on the housing 100, and the transmission shaft 110 has a cam 120.

[0059] Referring to Figure 2 In some specific embodiments, the cam 120 comprises 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 in a first angle range, the first needle roller 440 rolls in abutment with the first piston 130, and when the transmission shaft 110 rotates in a second angle range, the second needle roller 450 rolls in abutment with the second layer 430.

[0060] It can be understood that when the door leaf swings, the first needle roller 440 rolls in abutment with the first piston 130 and the second needle roller 450 rolls in abutment with the second layer 430, which avoids sliding friction between the cam 120 and the first piston 130, reduces the friction resistance between the cam 120 and the first piston 130, reduces the wear of the cam 120 and the first piston 130, so that the cam 120 and the first piston 130 are not easily damaged, and the service life is guaranteed.

[0061] In addition, the first needle 440 and the second needle 450 are arranged, so that the diameters of the first needle 440 and the second needle 450 are small, the first needle 440 and the second needle 450 can reduce the occupied space in the door closer, and the volume of the door closer is smaller.

[0062] 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 in the door leaf, the hidden installation of the door closer is realized, and meanwhile, the door closer can be installed without digging a pit on the ground. 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. The first needle 440 and the second needle 450 are arranged, so that the diameters of the first needle 440 and the second needle 450 are small, and the first needle 440 and the second needle 450 can be arranged and used in the limited space in the door closer.

[0063] Furthermore, the first needle 440 and the second needle 450 are arranged, so that the first needle 440 and the second needle 450 are respectively used as supporting 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, the service life of the supporting components is reduced due to long-term use of one supporting component, and thus the service life of the door closer is prolonged.

[0064] In some specific embodiments, the first piston 130 is provided with a first positioning groove 460, the first positioning groove 460 is matched with the first needle 440 to position the transmission shaft 110 in the closed door state, so that the position of the door leaf in the closed door state is more stable, and the door leaf is prevented from shaking.

[0065] In some specific embodiments, the first layer 420 is provided with a second positioning groove 470, the second positioning groove 470 is matched with the second needle 450 to position the transmission shaft 110 in the open door state, so that the door leaf can be positioned after being opened, the door leaf can be maintained in the open door state through cooperation of the second positioning groove 470 and the second needle 450, and the use of external force to keep the door leaf in the open door state is avoided, thereby facilitating use. In addition, when the door needs to be closed, the door leaf only needs to be pushed by using external force, so that the second needle 450 is separated from the second positioning groove 470, and then the external force is removed, and the reset spring 160 can automatically drive the door leaf to close the door.

[0066] Further, the first layer 420 is further provided with a third positioning groove 480, the third positioning groove 480 is used for cooperating with the second needle 450 to position, and the second positioning groove 470 and the third positioning groove 480 are respectively matched with the second needle 450 to position the transmission shaft 110 in two open door angles of the open door state, so that the door leaf can be positioned at two different open door angles, and thus the use demand of the user for maintaining the door leaf at different open door angles is met.

[0067] In some specific embodiments, the cam 120 is arranged symmetrically left and right, and the first needle roller 440 is arranged in two, and the two first needle rollers 440 are arranged symmetrically along the symmetry line of the cam 120 on the first layer 420, and the two first needle rollers 440 respectively abut and roll with the first piston 130 to make the transmission shaft 110 support the door leaf to open in two directions, so that the door leaf can swing open in two directions towards the inside and outside of the doorway.

[0068] Further, the first layer 420 is provided with two second positioning grooves 470, and the two second positioning grooves 470 are arranged symmetrically along the symmetry line of the cam 120 on the first layer 420, and the two second positioning grooves 470 are respectively matched with the second needle roller 450 to position the transmission shaft 110 in the open door state in two directions, so that the door leaf can be positioned in the open door state when the door leaf is opened in two directions towards the inside and outside of the doorway, and the use of external force to keep the door leaf in the open door state is eliminated, and further, the use is facilitated, and in addition, when the door needs to be closed, only the external force needs to be used to push the door leaf, so that the second needle roller 450 is separated from the second positioning groove 470, and then the external force is removed, and the reset spring 160 can automatically drive the door leaf to close.

[0069] Still further, the first layer 420 is further provided with two third positioning grooves 480, and the two third positioning grooves 480 are arranged symmetrically along the symmetry line of the cam 120 on the first layer 420, and the two second positioning grooves 470 and the two third positioning grooves 480 are respectively matched with the second needle roller 450 to position the transmission shaft 110 in two open door angles in the open door state in two directions, so that the door leaf can be positioned in two open door angles when the door leaf is opened in two directions towards the inside and outside of the doorway, and further, the use of the user to maintain the door leaf at different open door angles is adapted.

[0070] For the first piston 130, the first piston 130 is slidingly arranged in the housing 100, and the first piston 130 divides the inner cavity of the housing 100 into the first oil cavity 140 and the second oil cavity 150, and the first piston 130 abuts and drives with the cam 120.

[0071] For the reset spring 160, the reset spring 160 is located in the first oil cavity 140, and the reset spring 160 is used to push the first piston 130 to move to the second oil cavity 150 to reset to drive the door leaf to close.

[0072] The embodiment sets the shell 100, the transmission shaft 110, the first piston 130 and the reset spring 160, the transmission shaft 110 is rotationally arranged on the shell 100, the transmission shaft 110 has the cam 120, the first piston 130 is slidingly arranged in the shell 100, the first piston 130 divides the inner cavity of the shell 100 into the first oil cavity 140 and the second oil cavity 150, the first piston 130 is in abutment transmission with the cam 120, the reset spring 160 is located in the first oil cavity 140, and the reset spring 160 is used to push the first piston 130 to move reset to the second oil cavity 150 to drive the door leaf to close, so that the door closer is realized to automatically drive the door leaf to close through the reset spring 160.

[0073] With reference to Figure 3 In some specific embodiments, the shell 100 is further provided with the third piston 490, the third piston 490 is located between the first piston 130 and the reset spring 160, the third piston 490 divides the first oil cavity 140 into the left chamber 500 and the right chamber 510, the reset 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 reset spring 160, the third piston 490 is provided with the pressure relief valve 520, the pressure relief valve 520 is used for oil passing between the left chamber 500 and the right chamber 510, and the pressure relief valve 520 can reduce the pressure of the reset spring 160.

[0074] It can be understood that when the door closer needs to automatically close the door after the door is opened, the elastic potential energy accumulated by the compressed reset spring 160 is released, the elastic force generated by the reset spring 160 acts on the third piston 490 to push the third piston 490 to move reset, at this time, the pressure relief valve 520 on the third piston 490 can reduce the pressure of the reset spring 160, so that the third piston 490 offsets part of the elastic force of the reset spring 160 through the pressure relief valve 520 and then pushes the first piston 130 to move reset, avoiding that the reset spring 160 directly acts on the first piston 130, so that the third piston 490 can reduce the pressure of the reset spring 160, buffer the reset spring 160, reduce the impact force received by the first piston 130, reduce the extrusion force of the first piston 130 on the transmission shaft 110, reduce the risk that the first piston 130 pushes the transmission shaft 110, and ensure the service life of the door closer.

[0075] In some specific embodiments, the pressure relief valve 520 comprises a second valve seat 530 connected with the third piston 490, the second valve seat 530 having a first through hole 550, and a second valve core 540 having a pressure relief hole 560 for oil passing, when the third piston 490 compresses the return spring 160, the hydraulic oil in the shell 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 return spring 160 pushes the third piston 490 to reset, the hydraulic oil in the shell 100 pushes the second valve core 540 to the second valve seat 530 to close the first through hole 550.

[0076] 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, the hydraulic oil can pass through the first through hole 550 and the pressure relief hole 560 to ensure the oil passing area, during the door closing process, the compressed return spring 160 resets, the return spring 160 pushes the third piston 490 to reset, at this time the hydraulic oil can push the second valve core 540 to the second valve seat 530 to close the first through hole 550, so that the hydraulic oil can only pass through the pressure relief hole 560, reducing the oil passing area of the pressure relief 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 buffer the pressure relief of the return spring 160.

[0077] Further, the second valve core 540 is further provided with a first filter piece 570, and the first filter piece 570 is provided at least two, and the two first filter pieces 570 are respectively arranged at both ends of the pressure relief hole 560, and the first filter piece 570 is used to block the hydraulic oil splashing through the pressure relief hole 560.

[0078] It can be understood that since the diameter of the pressure relief hole 560 is smaller than the inner cavity cross-sectional area of the shell 100, when the hydraulic oil passes through the pressure relief hole 560, the oil passing area is suddenly reduced, which can cause the flow rate of the hydraulic oil passing through the pressure relief hole 560 to increase, by arranging the first filter piece 570 at both ends of the pressure relief hole 560, the first filter piece 570 can block the hydraulic oil on the jet path of the hydraulic oil, thereby preventing the high pressure of the hydraulic oil from splashing, and then, it is beneficial to reduce the pressure of the hydraulic oil after passing through the pressure relief hole 560.

[0079] In some specific embodiments, the pressure reducing valve 520 further comprises a first sliding sleeve 580, the first sliding sleeve 580 is slidingly arranged in the first through hole 550, the second valve core 540 comprises a core part 590 and a cover part 600, the core part 590 is connected with the inner wall of the first sliding sleeve 580, the cover part 600 is used for covering and sealing the first through hole 550, and a third oil channel is formed between the outer wall of the first sliding sleeve 580 and the inner wall of the first through hole 550 and communicates both ends of the first through hole 550.

[0080] It can be understood that the first sliding sleeve 580 is slidingly arranged in the first through hole 550, and the core part 590 of the second valve core 540 is connected with the inner wall of the first sliding sleeve 580, so that the first through hole 550 can limit and guide the sliding of the first sliding sleeve 580, thereby making the action of the second valve core 540 opening and closing the first through hole 550 more stable.

[0081] Further, the cross section of the outer wall of the first sliding sleeve 580 is polygonal, and the gap between the outer wall of the first sliding sleeve 580 and the inner wall of the first through hole 550 forms the third oil channel, so that the outer wall of the first sliding sleeve 580 has a part in abutment sliding with the inner wall of the first through hole 550 and also has a part with a gap between the outer wall of the first sliding sleeve 580 and the inner wall of the first through hole 550, thereby avoiding that the first sliding sleeve 580 completely blocks the first through hole 550, and further facilitating the formation of the third oil channel.

[0082] In some specific embodiments, the pressure reducing valve 520 further comprises an outer toothed washer 610 and a locking screw 620, the outer toothed washer 610 is arranged at one end of the first sliding sleeve 580 away from the second valve core 540, the outer toothed washer 610 has a toothed part, the toothed part is in abutment with the second valve seat 530 for limiting, and the locking screw 620 is threadedly connected with the first sliding sleeve 580 to fix the outer toothed washer 610 at the end of the first sliding sleeve 580.

[0083] It can be understood that when the door is opened, the third piston 490 compresses the return spring 160, and 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 sliding sleeve 580 moves towards the valve core, thereby the first sliding sleeve 580 can drive the outer toothed washer 610 to move close to the second valve seat 530, and when the toothed part of the outer toothed washer 610 is in abutment with the second valve seat 530, the toothed part can limit the movement of the first sliding sleeve 580, thereby avoiding that the first sliding sleeve 580 is separated from the first through hole 550, and at the same time, when the toothed part of the outer toothed washer 610 is in abutment with the second valve seat 530, the toothed part has a gap with the second valve seat 530, thereby avoiding that the outer toothed washer 610 blocks the first through hole 550.

[0084] In some specific embodiments, the third piston 490 is sleeved with a U-shaped sealing ring 630, the U-shaped sealing ring 630 is in abutment and sealing with the inner wall of the housing 100, thereby facilitating the sealing between the third piston 490 and the inner wall of the housing 100.

[0085] For the one-way valve 170, the one-way valve 170 is arranged on the first piston 130, the one-way valve 170 accommodates the hydraulic oil to flow 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, the first oil channel 180 communicates 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, 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 communicated with the first oil channel 180.

[0086] It can be understood that when the door closer drives the door leaf to close the door, the reset spring 160 drives the first piston 130 to move towards the second oil chamber 150, and the hydraulic oil in the second oil chamber 150 is extruded by the first piston 130, so that the hydraulic oil in the second oil chamber 150 flows from the first oil port 190 to the first oil channel 180 to the first oil chamber 140. During the movement of the first piston 130, at the beginning, the two first oil ports 190 are unobstructed, and the hydraulic oil in the second oil chamber 150 can enter the first oil channel 180 from the two first oil ports 190, so that the door closer can drive the door leaf to close the door at a high speed in the front door closing angle interval, so that the door leaf is quickly swung to close the door in the front door closing angle interval, and the door closing efficiency is improved. When the first piston 130 continues to move and blocks one of the first oil ports 190, the hydraulic oil in the second oil chamber 150 can only enter the first oil channel 180 from one of the first oil ports 190, so that the door closer can drive the door leaf to close the door at a low speed in the middle door closing angle interval, so that the door leaf can swing at a low speed before entering the door frame, avoiding the door leaf from being injured at the door frame due to too fast closing speed, and improving safety.

[0087] In some specific embodiments, the housing 100 is threadedly connected with two second valve needles 410, and the two second valve needles 410 are respectively used to adjust the opening degree of the two first oil ports 190 to adjust the oil passing speed of the two first oil ports 190, so that the opening degree of the two first oil ports 190 is respectively adjusted by the two second valve needles 410, the door closing swing speed of the door leaf in the front door closing angle interval and the middle door closing angle interval is respectively adjusted, and then the door closing swing speed of the door leaf driven by the door closer is adjustable.

[0088] In some specific embodiments, the one-way valve 170 has a safety valve hole 640, a safety valve bead 650 and a safety valve spring 660, the safety valve hole 640 communicates 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, the other end of the safety valve spring 660 abuts against the safety valve bead 650, and the safety valve spring 660 is used to drive the safety valve core to block the safety valve hole 640 from one end of the safety valve hole 640 close to the first oil chamber 140.

[0089] It can be understood that in the closed door state, when the normal state, the safety valve spring 660 has a greater elastic force on the safety valve ball 650 than the oil pressure of the second oil chamber 150, 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, causing the oil pressure in the second oil chamber 150 to be too large, the hydraulic oil 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 open the safety valve ball 650, so that the safety valve hole 640 is opened, so that the hydraulic oil in the second oil chamber 150 can flow from the safety valve hole 640 to the first oil chamber 140, and then, the pressure relief of the second oil chamber 150 is facilitated, and damage to the hydraulic oil in the second oil chamber 150 due to excessive oil pressure is avoided.

[0090] With reference to Figure 4 For the speed regulating valve 200, 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 arranged at one end of the second oil chamber 150 away from the first oil chamber 140. The second piston 220 is slidingly arranged in the first valve body 210. The first spring 230 is used to drive the second piston 220 to be close to the first piston 130.

[0091] With reference to Figure 5 For the second oil channel 260, the second oil channel 260 sequentially penetrates the side wall of the housing 100, the first valve body 210 and the second piston 220, and communicates the first oil chamber 140 and the second oil chamber 150. The first valve core 240 is slidingly arranged in the second piston 220. The second spring 250 is used to drive the first valve core 240 to seal the second oil channel 260. The first piston 130 moves back to push the first valve core 240 to open the first oil channel 180.

[0092] The embodiment sets the speed regulating valve 200 and the second oil channel 260, the speed regulating valve 200 includes the first valve body 210, the second piston 220, the first spring 230, the first valve core 240 and the second spring 250, the first valve body 210 is arranged at one end of the second oil cavity 150 away from the first oil cavity 140, 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 be close to the first piston 130, the second oil channel 260 penetrates the side wall of the shell 100, the first valve body 210 and the second piston 220 in sequence, and communicates the first oil cavity 140 and the second oil cavity 150, the first valve core 240 is slidably arranged in the second piston 220, and the second spring 250 is used to drive the first valve core 240 to seal the second oil channel 260, the first piston 130 is moved to reset to push the first valve core 240 to open the first oil channel 180, and it can be understood that in the rear door closing angle interval of the door closing process driven by the door closer, the first piston 130 pushes the first valve core 240 to open the first oil channel 180, and then pushes the second piston 220 to move, so that the hydraulic oil in the second oil cavity 150 can flow to the first oil cavity 140 through the second oil channel 260, thereby improving the oil return speed of the second oil cavity 150 to the first oil cavity 140, so that the door closer can improve the door leaf swing speed in the rear door closing angle interval of the door closing process, and then the door leaf swings at a high speed after entering the door frame, so that the door leaf can be closed with sufficient speed, and the door leaf can be smoothly closed.

[0093] The embodiment sets the first spring 230, the first spring 230 is used to drive the second piston 220 to be close to the first piston 130, so that when the first piston 130 releases the second piston 220, the first spring 230 can drive the second piston 220 to return to the position, and then the normal use of the second piston 220 in the next door closing process can be ensured.

[0094] The embodiment sets the second spring 250, the second spring 250 is used to drive the first valve core 240 to seal the second oil channel 260, so that when the first piston 130 releases the first valve core 240, the second spring 250 can drive the first valve core 240 to seal the second oil channel 260, to avoid the hydraulic oil in the first oil cavity 140 from flowing back to the second oil cavity 150 through the second oil channel 260, and at the same time, the function of improving the door leaf swing speed in the rear door closing angle interval in the next door closing process can be ensured.

[0095] In some specific embodiments, the first piston 130 abuts against the first valve core 240 and the second piston 220 through the one-way valve 170.

[0096] In some specific embodiments, the side wall of the first valve body 210 has a first hole 270 for forming 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 for forming a part of the second oil channel 260, the first annular groove 280 is communicated with the hole opening 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 hole opening diameter of the first hole 270.

[0097] It can be understood that, during the closing process of the door leaf, the first piston 130 pushes 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 greater than the hole opening diameter of the first hole 270, so that the first annular groove 280 can keep communicated with the first hole 270 during the movement of the second piston 220, avoiding the misalignment of the first annular groove 280 and the hole opening of the first hole 270 to cause the second oil channel 260 unable to pass oil, and further ensuring that the second oil channel 260 can keep unobstructed during the movement of the second piston 220.

[0098] In some specific embodiments, the side wall of the first valve body 210 has a first hole 270 for forming 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 degree of the first hole 270 to adjust the oil passing speed of the second oil channel 260, so that the closing swing speed of the door leaf can be adjusted by adjusting the oil passing speed of the second oil channel 260, and further the closing swing speed of the door leaf driven by the door closer can be adjusted.

[0099] In some specific embodiments, the second piston 220 is provided with a T-shaped hole 300 for forming a part of the second oil channel 260, the T-shaped hole 300 has a small-diameter port communicated with the second oil cavity 150, the first valve core 240 is provided as a T-shaped needle, and the T-shaped hole 300 accommodates the sliding of the first valve core 240, when the second spring 250 extrudes 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.

[0100] It can be understood that, by setting the T-shaped hole 300 on the second piston 220 and cooperating with the first valve core 240, the T-shaped hole 300 can limit the position of the first valve core 240, avoiding the first valve core 240 being completely extruded out of the second piston 220 by the second spring 250, and at the same time, when the second spring 250 extrudes 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, so that the first piston 130 can first push the end of the first valve core 240 to open the T-shaped hole 300 and then push the second piston 220 to move, and further the second oil channel 260 can keep unobstructed during the movement of the second piston 220 by the first piston 130.

[0101] Further, 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 in clearance fit with the small-diameter hole segment 340, the outer circumferential surface of the large-diameter needle segment 310 is in polygonal cross section, the edges of the outer circumferential surface of the large-diameter needle segment 310 are in sliding fit with the large-diameter hole segment 330, the flat surfaces of the outer circumferential surface of the large-diameter needle segment 310 are in clearance fit with the large-diameter hole segment 330, and the end surface of the large-diameter needle segment 310 close to the small-diameter needle segment 320 is in abutment with the end surface of the small-diameter hole segment 340 to seal the T-shaped hole 300.

[0102] It can be understood that, by making the outer circumferential surface of the large-diameter needle segment 310 in polygonal cross section, the edges of the outer circumferential surface of the large-diameter needle segment 310 are in sliding fit with the large-diameter hole segment 330, and the flat surfaces of the outer circumferential surface of the large-diameter needle segment 310 are in clearance fit with the large-diameter hole segment 330, the outer circumferential surface of the large-diameter needle segment 310 can be in sliding fit with the large-diameter hole segment 330 while ensuring that there is clearance between the outer circumferential surface of the large-diameter needle segment 310 and the large-diameter hole segment 330 for accommodating hydraulic oil to pass through, so that the clearance between the outer circumferential surface of the large-diameter needle segment 310 and the large-diameter hole segment 330 and the clearance between the small-diameter needle segment 320 and the small-diameter hole segment 340 can form part of the second oil passage 260.

[0103] In some specific embodiments, the speed regulating valve 200 further comprises a distance adjusting needle 350, the distance adjusting needle 350 is in threaded connection with the side wall of the first valve body 210, the distance adjusting needle 350 has a variable-diameter segment 360, the second piston 220 has a distance adjusting groove 370 arranged along the radial direction of the second piston 220, and the variable-diameter segment 360 is in clearance fit with the distance adjusting groove 370. The distance adjusting needle 350 is used to adjust the position of the second piston 220 in the second oil cavity 150.

[0104] It can be understood that, by adjusting the depth of the distance adjusting needle 350 in the first valve body 210, the position of the variable-diameter segment 360 with different diameters can be matched with the distance adjusting groove 370, so that the movable range of the second piston 220 can be adjusted, the position of the second piston 220 in the second oil cavity 150 can be adjusted, and then the door leaf angular position at which the door closer starts to regulate the speed valve 200 can be conveniently changed.

[0105] Further, the distance adjusting groove 370 has a bevel wall mouth portion 380, the slope of the bevel wall mouth portion 380 is consistent with the slope of the variable-diameter segment 360, so that when the variable-diameter segment 360 is in abutment and limited by the distance adjusting groove 370, the bevel wall mouth portion 380 can be in close contact with one side of the variable-diameter segment 360, and then the matching of the variable-diameter segment 360 and the distance adjusting groove 370 is more stable.

[0106] In some specific embodiments, the distance adjusting groove 370 penetrates 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 penetrates through the distance adjusting groove 370 and is limited by the limiting hole 390, so that the support of the first valve body 210 to the distance adjusting needle 350 is more stable, and then the limiting of the distance adjusting needle 350 to the second piston 220 is more stable.

[0107] In some specific embodiments, the third spring 400 is arranged in the limiting hole 390, and the two ends of the second spring 250 abut against the bottom wall of the limiting hole 390 and the end of the distance adjusting needle 350, respectively, 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 loose due to the gap of the threaded cooperation between the distance adjusting needle 350 and the first valve body 210, and then the distance adjusting needle 350 is more stable.

[0108] In the description of the present specification, the description of the terms "one embodiment, some embodiments, illustrative embodiments, examples, specific examples, or some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0109] The terms "first, second, third, fourth" and the like (if any) in the specification of the present application and claims and the above-described drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0110] It should also be noted that in the description of the present specification, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or sequence between the entities or operations.

[0111] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device including a series of steps or units does not necessarily have to be limited to only those steps or units clearly listed, but can also include other steps or units not clearly listed or inherent to the process, method, product, or device.

[0112] Also, the term "comprising" or "including" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a... " does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0113] The above detailed description of the embodiments of the present application is made with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A door closer characterised in that, The utility model relates to a hydraulic door closer, including: A shell (100); A transmission shaft (110) is rotationally arranged on the shell (100) and has a cam (120); A first piston (130) is slidingly arranged in the shell (100) and divides the inner cavity of the shell (100) into a first oil cavity (140) and a second oil cavity (150), and the first piston (130) is in abutment with the cam (120) to drive; A reset spring (160) is arranged in the first oil cavity (140) and is used to push the first piston (130) to move to the second oil cavity (150) to reset and drive the door leaf to close the door; A one-way valve (170) is arranged on the first piston (130) and is used to accommodate hydraulic oil to flow from the first oil cavity (140) to the second oil cavity (150), a first oil channel (180) is formed in the side wall of the shell (100) and is used to communicate the first oil cavity (140) and the second oil cavity (150), and two first oil ports (190) are formed in the side wall of the second oil cavity (150) and are arranged in sequence along the moving direction of the first piston (130), and the two first oil ports (190) are both communicated with the first oil channel (180); A speed regulating valve (200) comprises 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 the end of the second oil cavity (150) away from the first oil cavity (140), the second piston (220) is slidingly arranged in the first valve body (210), and the first spring (230) is used to drive the second piston (220) to be close to the first piston (130); The speed regulating valve (200) further comprises a distance adjusting needle (350), the distance adjusting needle (350) is threadedly connected with the side wall of the first valve body (210), the distance adjusting needle (350) has a variable diameter section (360), the second piston (220) has a distance adjusting groove (370) arranged along the radial direction of the second piston (220), the variable diameter section (360) is in clearance fit with the distance adjusting groove (370), the variable diameter section (360) is in clearance fit with the distance adjusting groove (370), and the distance adjusting needle (350) is used to adjust the position of the second piston (220) in the second oil cavity (150); A second oil channel (260) penetrates the side wall of the shell (100), the first valve body (210) and the second piston (220) in sequence, and is used to communicate the first oil cavity (140) and the second oil cavity (150), the first valve core (240) is slidingly arranged in the second piston (220), the second spring (250) is used to drive the first valve core (240) to seal the second oil channel (260), and the first piston (130) is reset to push the first valve core (240) to open the first oil channel (180).

2. A door closer according to claim 1, wherein The side wall of the first valve body (210) has a first hole (270) for forming a part of the second oil passage (260), and the outer peripheral wall of the second piston (220) is provided with a first annular groove (280) for forming a part of the second oil passage (260), the first annular groove (280) is communicated with 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, wherein The side wall of the first valve body (210) has a first hole (270) for forming a part of the second oil passage (260), and the first valve body (210) is threadedly connected with a first valve needle (290) for adjusting the opening degree of the first hole (270) to adjust the oil passing speed of the second oil passage (260).

4. A door closer according to claim 1, wherein The second piston (220) is provided with a T-shaped hole (300) for forming a part of the second oil passage (260), the small-diameter port of the T-shaped hole (300) is communicated with the second oil cavity (150), the first valve core (240) is provided as a T-shaped needle, the T-shaped hole (300) accommodates the sliding of the first valve core (240), and when the second spring (250) extrudes 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).

5. A door closer according to claim 4, wherein The first valve core (240) includes a large-diameter needle segment (310) and a small-diameter needle segment (320), 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) is in clearance fit 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 of the outer peripheral surface of the large-diameter needle segment (310) are in sliding fit with the large-diameter hole segment (330), the flat surfaces of the outer peripheral surface of the large-diameter needle segment (310) are in clearance fit with the large-diameter hole segment (330), and the end face of the large-diameter needle segment (310) close to the small-diameter needle segment (320) is in abutment with the end face of the small-diameter hole segment (340) to seal the T-shaped hole (300).

6. A door closer according to claim 1, wherein The pitch adjusting groove (370) has a bevel wall mouth portion (380) with a slope consistent with that of the variable diameter segment (360).

7. A door closer according to claim 1, wherein The pitch adjusting groove (370) penetrates 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 pitch adjusting needle (350) penetrates the pitch adjusting groove (370) and is limited by the limiting hole (390).

8. A door closer according to claim 7, wherein A third spring (400) is arranged in the limiting hole (390), two ends of the second spring (250) respectively abut against a bottom wall of the limiting hole (390) and an 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).

9. A door closer according to claim 1, wherein The shell (100) is threadedly connected with two second valve needles (410), and the two second valve needles (410) are respectively used for adjusting the opening degrees of the two first oil ports (190) to adjust the oil passing speeds of the two first oil ports (190).

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