Piston structure and door closer

Abstract

The utility model discloses a piston structure and discloses a door closer with the piston structure, the piston structure comprises a first piston, a reset spring and a second piston, the first piston is arranged in a shell in a sliding mode and abuts against a cam in a transmission mode; the reset spring is arranged in the shell, and one end abuts against the inner wall of the end of the shell. The second piston is arranged in the shell in a sliding mode and located between the first piston and the reset spring, the two ends of the second piston are used for abutting against the first piston and the reset spring respectively, and a pressure reducing valve is arranged and used for reducing pressure of the reset spring. According to the piston structure, the reset spring can be decompressed and buffered, the impulsive force borne by the piston is reduced, the extrusion force of the piston on the transmission shaft is reduced, the risk that the transmission shaft is deduced by the piston is reduced, and the service life of a door closer is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of door closer structure, in particular to a piston structure and door closer. BACKGROUND

[0002] The door closer is a kind of machine that can automatically close door, it is a hydraulic device similar to spring on the door head, when door is opened, it can be automatically closed by releasing the compression, it has the function of spring door, and can ensure that door is accurately and timely closed to 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 with 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 end inner wall 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] When using, when opening the door, the transmission shaft is rotated relative to the housing, so that the cam on the transmission shaft is synchronously rotated to push the piston to compress the return spring, when the door is opened, the elastic potential energy accumulated by the return spring is released, the piston is reversely pushed to reset, so as to drive the cam to rotate to reset, and the door is closed.

[0006] In the prior art, the elastic force of the return spring is directly applied to the piston during the process of closing the door.

[0007] However, the elastic force of the return spring is large, and the impact force of the return spring applied to the piston is easy to push the transmission shaft by the piston, which leads to short service life of the door closer. INVENTION CONTENTS

[0008] The utility model aims at at least one of the technical problems existing in the prior art is solved.The utility model provides a piston structure, can reduce pressure buffering to return spring, reduce the impact force that piston receives, reduce the extrusion force of piston to transmission shaft, reduce the risk that piston pushes transmission shaft, guarantee the service life of door closer.

[0009] The utility model further provides a door closer with the piston structure.

[0010] According to the piston structure of the first aspect embodiment of the utility model, it comprises:

[0011] The first piston is slidably arranged in the housing and abuts against the cam to drive;

[0012] The return spring is arranged in the housing and abuts against the end inner wall of the housing at one end;

[0013] A second piston is slidingly arranged in the housing between the first piston and the reset spring, and is arranged to abut the first piston and the reset spring at two ends thereof, and is provided with a pressure relief valve for relieving pressure of the reset spring.

[0014] According to the piston structure, at least the following beneficial effects are achieved:

[0015] The second piston is arranged between the first piston and the reset spring, and the two ends of the second piston are arranged to abut the first piston and the reset spring, respectively, and the second piston is provided with a pressure relief valve, and the pressure relief valve is used for relieving pressure of the reset spring, and 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 is released, and the elastic force generated by the reset spring acts on the second piston to push the second piston to reset, at this time, the pressure relief valve on the second piston can relieve the pressure of the reset spring, so that the second piston pushes the first piston to reset after offsetting part of the elastic force of the reset spring through the pressure relief valve, avoiding the reset spring directly acting on the first piston, so that the second piston can relieve the pressure of the reset spring, reduce the impact force on the first piston, reduce the extrusion force of the first piston on the transmission shaft, reduce the risk of the first piston pushing the transmission shaft, and ensure the service life of the door closer.

[0016] According to some embodiments of the utility model, the pressure relief valve comprises a first valve seat and a first valve core, the first valve seat is connected with the second piston, the first valve seat has a first through hole, the first valve core has a pressure relief hole for oil passing, when the second piston compresses the reset spring, the hydraulic oil in the housing pushes the first valve core away from the first valve seat to make the first through hole open for oil passing, when the reset spring pushes the second piston to reset, the hydraulic oil in the housing pushes the first valve core to the first valve seat to make the first valve core close the first through hole.

[0017] The advantages of this invention are: The pressure-reducing valve includes a first valve seat and a first valve core. The first valve seat is connected to a second piston. The first valve seat has a first through hole, and the first valve core has a pressure-reducing hole for oil passage. When the second piston compresses the return spring, the hydraulic oil in the housing pushes the first valve core away from the first valve seat to open the first through hole for oil passage. When the return spring pushes the second piston back to its original position, the hydraulic oil in the housing pushes the first valve core towards the first valve seat to close the first through hole. It can be understood that during the opening process, the second piston compresses the return spring, at which point the hydraulic oil can... The valve core is pushed away from the first valve seat to open the first through hole, allowing hydraulic oil to pass through the first through hole and the pressure reducing hole, ensuring the oil passage area. During the closing process, the compressed return spring returns to its original position, pushing the second piston back to its original position. At this time, the hydraulic oil can push the first valve core towards the first valve seat, causing the first valve core to close the first through hole. Thus, the hydraulic oil can only pass through the pressure reducing hole, reducing the oil passage area of ​​the pressure reducing valve and decreasing the moving speed of the second piston. This allows the second piston to counteract part of the spring force of the return spring, thereby enabling the second piston to depressurize and buffer the return spring.

[0018] According to some embodiments of the present invention, the first valve core is further provided with a first filter element, and at least two first filter elements are provided, with the at least two first filter elements respectively disposed at both ends of the pressure reducing hole. The first filter element is used to block hydraulic oil splashing through the pressure reducing hole.

[0019] The advantage of this invention is that the first valve core is further provided with a first filter element, and at least two first filter elements are provided. The at least two first filter elements are respectively provided at both ends of the pressure reducing hole. The first filter elements are used to block the hydraulic oil splashing through the pressure reducing hole. It can be understood that since the diameter of the pressure reducing hole is smaller than the cross-sectional area of ​​the inner cavity of the shell, when the hydraulic oil passes through the pressure reducing hole, the oil passage area is reduced sharply, which will cause the hydraulic oil flow rate through the pressure reducing hole to increase. By providing first filter elements at both ends of the pressure reducing hole, the first filter elements can block the hydraulic oil in the injection path of the hydraulic oil, thereby preventing the high-pressure splashing of the hydraulic oil, and thus facilitating the pressure reduction of the hydraulic oil after passing through the pressure reducing hole.

[0020] According to some embodiments of the present invention, the pressure reducing valve further includes a first sliding sleeve, which is slidably disposed in the first through hole. The first valve core includes a core and a cover. The core is connected to the inner wall of the first sliding sleeve, and the cover is used to cover and seal the first through hole. A first oil passage connecting the two ends of the first through hole is provided between the outer wall of the first sliding sleeve and the inner wall of the first through hole.

[0021] The advantages of this invention are: by including a first sliding sleeve in the pressure reducing valve, the first sliding sleeve is slidably disposed in the first through hole, the first valve core includes a core and a cover, the core is connected to the inner wall of the first sliding sleeve, the cover is used to cover and seal the first through hole, and a first oil passage connecting the two ends of the first through hole is provided between the outer wall of the first sliding sleeve and the inner wall of the first through hole. It can be understood that the first sliding sleeve is slidably disposed in the first through hole, and the core of the first valve core is connected to the inner wall of the first sliding sleeve, so that the first through hole can limit and guide the sliding of the first sliding sleeve, thereby making the opening and closing of the first through hole by the first valve core more stable.

[0022] According to some embodiments of the present invention, the cross-section of the outer wall of the first sliding sleeve is polygonal, and the gap between the outer wall of the first sliding sleeve and the inner wall of the first through hole forms the first oil passage.

[0023] The advantage of this invention is that by making the cross-section of the outer wall of the first sliding sleeve polygonal, the gap between the outer wall of the first sliding sleeve and the inner wall of the first through hole forms the first oil passage. This allows the outer wall of the first sliding sleeve to slide against the inner wall of the first through hole in part, while also having a gap between it and the inner wall of the first through hole. This avoids the first sliding sleeve from completely blocking the first through hole, and thus facilitates the formation of the first oil passage.

[0024] According to some embodiments of the present invention, the pressure reducing valve further includes an external toothed washer and a locking screw. The external toothed washer is disposed at the end of the first sliding sleeve away from the first valve core. The external toothed washer has teeth, which abut against and limit the first valve seat. The locking screw is threadedly connected to the first sliding sleeve to fix the external toothed washer at the end of the first sliding sleeve.

[0025] The advantages of this invention are: by including an external toothed washer and a locking screw in the pressure reducing valve, the external toothed washer is located at the end of the first sliding sleeve away from the first valve core. The external toothed washer has teeth that abut against and limit the first valve seat. The locking screw is threadedly connected to the first sliding sleeve to fix the external toothed washer at the end of the first sliding sleeve. It can be understood that when the door is opened, the second piston compresses the return spring. When the hydraulic oil passes through the pressure reducing valve, the hydraulic oil pushes the first valve core away from the first valve seat. At this time, the first sliding sleeve moves towards the valve core. Thus, the first sliding sleeve can drive the external toothed washer closer to the first valve seat. When the teeth of the external toothed washer abut against the first valve seat, it can limit the movement of the first sliding sleeve and prevent the first sliding sleeve from disengaging from the first through hole. At the same time, after the teeth of the external toothed washer abut against the first valve seat, there is a gap between the teeth and the first valve seat, which prevents the external toothed washer from blocking the first through hole.

[0026] According to some embodiments of the present invention, the first piston and the second piston sequentially divide the inner cavity of the housing into a first oil chamber, a second oil chamber, and a third oil chamber. The return spring is located in the third oil chamber. Oil passes between the second oil chamber and the third oil chamber through the pressure reducing valve. The side wall of the housing has a second oil passage for oil passage between the first oil chamber and the second oil chamber. The side wall of the housing is also provided with a first valve needle for adjusting the oil passage area of ​​the second oil passage.

[0027] The advantages of this invention are: by using a first piston and a second piston to sequentially divide the inner cavity of the housing into a first oil chamber, a second oil chamber, and a third oil chamber, a return spring is located in the third oil chamber, and oil passes between the second and third oil chambers through a pressure reducing valve. The side wall of the housing has a second oil passage for oil passage between the first and second oil chambers. The side wall of the housing is also provided with a first valve needle for adjusting the oil passage area of ​​the second oil passage. It can be understood that by adjusting the first valve needle, the moving speed of the first piston can be adjusted, thereby facilitating the adjustment of the swing speed of the door leaf of the automatic closing door.

[0028] According to some embodiments of the present invention, the first piston is provided with a one-way valve, which allows hydraulic oil from the second oil chamber to flow into the first oil chamber.

[0029] The advantage of this invention is that by providing a one-way valve on the first piston, the one-way valve allows the hydraulic oil in the second oil chamber to flow into the first oil chamber, thereby increasing the maximum upper limit of the oil flow when the door is opened, and thus enabling the door closer to allow a greater opening swing speed.

[0030] According to some embodiments of the present invention, the one-way valve has a safety valve orifice, a safety valve bead, and a safety valve spring. The safety valve orifice connects the first oil chamber and the second oil chamber. One end of the safety valve spring abuts against the one-way valve, and the other end of the safety valve spring abuts against the safety valve bead. The safety valve spring is used to drive the safety valve core to block the safety valve orifice from the end of the safety valve orifice near the second oil chamber.

[0031] The advantages of this invention are as follows: The one-way valve includes a safety valve orifice, a safety valve ball, and a safety valve spring. The safety valve orifice connects the first and second oil chambers. One end of the safety valve spring abuts against the one-way valve, and the other end abuts against the safety valve ball. The safety valve spring is used to drive the safety valve core to seal the safety valve orifice from the end closest to the second oil chamber. Under normal conditions, when the door is closed, the spring force of the safety valve spring on the safety valve ball is greater than the oil pressure in the first oil chamber. The safety valve spring can drive the safety valve ball to continuously seal the safety valve orifice, keeping it normally closed. When the second oil passage is blocked or the door is interfered with by external force, causing excessive oil pressure in the first oil chamber, the hydraulic oil pressure in the first oil chamber exceeds the spring force of the safety valve spring. The hydraulic oil in the first oil chamber can then open the safety valve ball, causing the safety valve orifice to open. This allows the hydraulic oil in the first oil chamber to flow from the safety valve orifice to the second oil chamber, facilitating pressure relief in the first oil chamber and preventing excessive hydraulic oil pressure in the first oil chamber from damaging the door closer.

[0032] A door closer according to a second aspect of the present invention includes a piston structure as described in the first aspect of the present invention.

[0033] A door closer according to an embodiment of the present utility model has at least the following beneficial effects:

[0034] This invention employs a piston structure with a second piston positioned between the first piston and the return spring. The two ends of the second piston abut against the first piston and the return spring, respectively. The second piston is equipped with a pressure-reducing valve to reduce the pressure on the return spring. Understandably, when the door is opened and the door closer needs to automatically close, the elastic potential energy stored in the compressed return spring is released. The spring force generated by the return spring acts on the second piston, pushing it to move and return to its original position. At this time, the pressure-reducing valve on the second piston reduces the pressure on the return spring, allowing the second piston to offset part of the spring force before pushing the first piston to move and return to its original position. This avoids the return spring directly acting on the first piston. Therefore, the second piston can buffer the pressure on the return spring, reducing the impact force on the first piston, decreasing the squeezing force of the first piston on the drive shaft, reducing the risk of the first piston pushing the drive shaft away, and ensuring the service life of the door closer.

[0035] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a piston structure and a door closer according to an embodiment of the present utility model;

[0038] Figure 2 for Figure 1 The enlarged view at point A is shown;

[0039] Figure 3 for Figure 1 The enlarged view at point B is shown.

[0040] Reference numerals: 100-First piston, 110-Housing, 120-Cam, 130-Return spring, 140-Second piston, 150-Pressure reducing valve, 160-First valve seat, 170-First valve core, 180-First through hole, 190-Pressure reducing hole, 200-First filter, 210-First sliding sleeve, 220-Core, 230-Cover, 240-First oil passage, 250-External toothed washer, 260-Locking screw Wire, 270-first oil chamber, 280-second oil chamber, 290-third oil chamber, 300-second oil passage, 310-first valve needle, 320-one-way valve, 330-safety valve hole, 340-safety valve bead, 350-safety valve spring, 360-second filter, 370-U-shaped sealing ring, 380-second valve seat, 390-second valve core, 400-third oil passage, 410-limit pin, 420-third filter. Detailed Implementation

[0041] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0042] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0043] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" and "second" are mentioned, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0044] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation, connection, and linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0045] A piston structure and a door closer according to an embodiment of the present invention are described below with reference to the accompanying drawings.

[0046] This utility model aims to provide an embodiment of a piston structure and a door closer.

[0047] Reference Figure 1 In this embodiment, a door closer mainly includes a piston structure, which includes a first piston 100, a return spring 130, and a second piston 140.

[0048] In terms of installation, one of the drive shaft and housing 110 is installed on the door leaf, and the other of the drive shaft and housing 110 is installed on the door frame or the ground.

[0049] The drive shaft is rotatably connected to the housing 110.

[0050] For cam 120, cam 120 is mounted on the drive shaft.

[0051] The first piston 100 is slidably disposed within the housing 110, and the first piston 100 abuts against the cam 120 for transmission.

[0052] The return spring 130 is disposed inside the housing 110, and one end of the return spring 130 abuts against the inner wall of the end of the housing 110.

[0053] The second piston 140 is slidably disposed within the housing 110. The second piston 140 is located between the first piston 100 and the return spring 130. The two ends of the second piston 140 are respectively used to abut against the first piston 100 and the return spring 130. The second piston 140 is provided with a pressure reducing valve 150, which is used to reduce the pressure of the return spring 130.

[0054] In this embodiment, a second piston 140 is provided between the first piston 100 and the return spring 130. The two ends of the second piston 140 are respectively used to abut against the first piston 100 and the return spring 130. The second piston 140 is equipped with a pressure-reducing valve 150, which is used to reduce the pressure on the return spring 130. It can be understood that when the door is opened and the door closer needs to automatically close, the elastic potential energy accumulated in the compressed return spring 130 is released. The elastic force generated by the return spring 130 acts on the second piston 140, pushing the second piston 140 to move and return to its original position. The pressure reducing valve 150 on the second piston 140 can reduce the pressure on the return spring 130, so that the second piston 140 can offset part of the elastic force of the return spring 130 through the pressure reducing valve 150 before pushing the first piston 100 to move and reset. This avoids the return spring 130 acting directly on the first piston 100. As a result, the second piston 140 can reduce the pressure on the return spring 130, reduce the impact force on the first piston 100, reduce the squeezing force of the first piston 100 on the drive shaft, reduce the risk of the first piston 100 pushing the drive shaft, and ensure the service life of the door closer.

[0055] Reference Figure 2 In some specific embodiments, the pressure reducing valve 150 includes a first valve seat 160 and a first valve core 170. The first valve seat 160 is connected to the second piston 140. The first valve seat 160 has a first through hole 180, and the first valve core 170 has a pressure reducing hole 190 for oil passage. When the second piston 140 compresses the return spring 130, the hydraulic oil in the housing 110 pushes the first valve core 170 away from the first valve seat 160 to open the first through hole 180 for oil passage. When the return spring 130 pushes the second piston 140 to reset, the hydraulic oil in the housing 110 pushes the first valve core 170 towards the first valve seat 160 to close the first through hole 180.

[0056] Understandably, during the opening process, the second piston 140 compresses the return spring 130. At this time, the hydraulic oil can push the first valve core 170 away from the first valve seat 160, so that the first through hole 180 is open. The hydraulic oil can pass through the first through hole 180 and the pressure reducing hole 190, ensuring the oil passage area. During the closing process, the compressed return spring 130 returns to its original position. The return spring 130 pushes the second piston 140 to its original position. At this time, the hydraulic oil can push the first valve core 170 towards the first valve seat 160, so that the first valve core 170 closes the first through hole 180. Thus, the hydraulic oil can only pass through the pressure reducing hole 190, reducing the oil passage area of ​​the pressure reducing valve 150 and reducing the moving speed of the second piston 140. This allows the second piston 140 to counteract part of the elastic force of the return spring 130, thereby allowing the second piston 140 to depressurize and buffer the return spring 130.

[0057] Furthermore, the first valve core 170 is also provided with a first filter 200. At least two first filter 200s are provided, and the at least two first filter 200s are respectively provided at both ends of the pressure reducing hole 190. The first filter 200s are used to block the hydraulic oil splashing through the pressure reducing hole 190.

[0058] Understandably, since the diameter of the pressure relief hole 190 is smaller than the cross-sectional area of ​​the inner cavity of the housing 110, when the hydraulic oil passes through the pressure relief hole 190, the oil passage area decreases sharply, which will cause the hydraulic oil to flow faster through the pressure relief hole 190. By setting the first filter 200 at both ends of the pressure relief hole 190, the first filter 200 can block the hydraulic oil in the injection path of the hydraulic oil, thereby preventing the high-pressure splashing of the hydraulic oil, and thus facilitating the pressure relief of the hydraulic oil after passing through the pressure relief hole 190.

[0059] Specifically, the first filter 200 can be configured as a copper-based powder metallurgy sintered filter, which has a number of filter holes for oil passage.

[0060] Furthermore, a second filter 360 is provided at the end of the pressure relief hole 190 away from the return spring 130, which helps to further reduce the oil pressure splashed by the pressure relief hole 190.

[0061] In some specific embodiments, the pressure reducing valve 150 further includes a first sliding sleeve 210, which is slidably disposed in the first through hole 180. The first valve core 170 includes a core portion 220 and a cover portion 230. The core portion 220 is connected to the inner wall of the first sliding sleeve 210, and the cover portion 230 is used to cover and seal the first through hole 180. A first oil passage 240 connecting the two ends of the first through hole 180 is provided between the outer wall of the first sliding sleeve 210 and the inner wall of the first through hole 180.

[0062] It is understandable that the first sliding sleeve 210 is slidably disposed in the first through hole 180, and the core 220 of the first valve core 170 is connected to the inner wall of the first sliding sleeve 210, so that the first through hole 180 can limit and guide the sliding of the first sliding sleeve 210, thereby making the opening and closing of the first through hole 180 of the first valve core 170 more stable.

[0063] Furthermore, the cross-section of the outer wall of the first sliding sleeve 210 is polygonal, and the gap between the outer wall of the first sliding sleeve 210 and the inner wall of the first through hole 180 forms the first oil passage 240. Thus, the outer wall of the first sliding sleeve 210 has both a portion that slides against the inner wall of the first through hole 180 and a portion that has a gap with the inner wall of the first through hole 180, thereby preventing the first sliding sleeve 210 from completely blocking the first through hole 180 and facilitating the formation of the first oil passage 240.

[0064] In some specific embodiments, the pressure reducing valve 150 further includes an external toothed washer 250 and a locking screw 260. The external toothed washer 250 is disposed at the end of the first sliding sleeve 210 away from the first valve core 170. The external toothed washer 250 has teeth that abut against and limit the first valve seat 160. The locking screw 260 is threadedly connected to the first sliding sleeve 210 to fix the external toothed washer 250 at the end of the first sliding sleeve 210.

[0065] Understandably, when the door is opened, the second piston 140 compresses the return spring 130. When the hydraulic oil passes through the pressure reducing valve 150, the hydraulic oil pushes the first valve core 170 away from the first valve seat 160. At this time, the first sliding sleeve 210 moves towards the valve core. Thus, the first sliding sleeve 210 can drive the external toothed washer 250 to approach the first valve seat 160. When the teeth of the external toothed washer 250 abut against the first valve seat 160, they can limit the movement of the first sliding sleeve 210, preventing the first sliding seat from disengaging from the first through hole 180. At the same time, after the teeth of the external toothed washer 250 abut against the first valve seat 160, there is a gap between the teeth and the first valve seat 160, preventing the external toothed washer 250 from blocking the first through hole 180.

[0066] In some specific embodiments, a U-shaped sealing ring 370 is fitted on the second piston 140, and the U-shaped sealing ring 370 abuts and seals against the inner wall of the housing 110, thereby facilitating the sealing between the second piston 140 and the inner wall of the housing 110.

[0067] Reference Figure 3In some specific embodiments, the first piston 100 and the second piston 140 sequentially divide the inner cavity of the housing 110 into a first oil chamber 270, a second oil chamber 280 and a third oil chamber 290. The return spring 130 is located in the third oil chamber 290. Oil passes between the second oil chamber 280 and the third oil chamber 290 through a pressure reducing valve 150. The side wall of the housing 110 has a second oil passage 300, which is used for oil passage between the first oil chamber 270 and the second oil chamber 280. The side wall of the housing 110 is also provided with a first valve needle 310, which is used to adjust the oil passage area of ​​the second oil passage 300.

[0068] It is understandable that by adjusting the first valve needle 310, the moving speed of the first piston 100 can be adjusted, thereby facilitating the adjustment of the swing speed of the door leaf when the door is automatically closing.

[0069] Specifically, the first valve needle 310 is threadedly connected to the housing 110, so that by turning the first valve needle 310, the depth of the first valve needle 310 inserted into the second oil passage 300 can be adjusted, thereby adjusting the oil passage area of ​​the second oil passage 300.

[0070] Furthermore, the first piston 100 is provided with a one-way valve 320, which allows hydraulic oil from the second oil chamber 280 to flow into the first oil chamber 270. This helps to increase the maximum oil flow limit when the door is opened, thereby enabling the door closer to allow a larger opening swing speed.

[0071] In some specific embodiments, the one-way valve 320 includes a second valve seat 380 and a second valve core 390. The second valve seat 380 is connected to the first piston 100 and has a second through hole. The second valve core 390 is slidably disposed with respect to the second through hole and has a third oil passage 400. The hydraulic oil in the second oil chamber 280 pushes the second valve core 390 away from the second valve seat 380 to open the third oil passage 400 for oil passage. The hydraulic oil in the first oil chamber 270 pushes the second valve core 390 toward the second valve seat 380 to close the third oil passage 400, thereby facilitating one-way oil passage of the one-way valve 320.

[0072] Furthermore, a limit pin 410 is provided on the second valve core 390. The limit pin 410 abuts against the second valve seat 380 to limit the second valve core 390 from disengaging from the second valve seat 380, thereby preventing the second valve core 390 from completely disengaging from the second valve seat 380.

[0073] In some specific embodiments, the first piston 100 is provided with a third filter 420, which is located at one end of the third oil passage 400 near the second oil chamber 280, thereby facilitating the decompression of hydraulic oil passing through the third oil passage 400.

[0074] In some specific embodiments, the safety valve orifice 330 is disposed in the second valve core 390, and one end of the safety valve orifice 330 is connected to the third oil passage 400.

[0075] In the description of this specification, references to terms such as "an embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] The terms "first," "second," "third," "fourth," etc. (if applicable) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0077] It should also be noted that, in the description of this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0078] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may also include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or apparatus.

[0079] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0080] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A piston structure characterized by, The utility model relates to a hydraulic pressure reducing valve, comprising: a first piston (100) slidingly arranged in a housing (110) and abutting against a cam (120) for transmission; a return spring (130) arranged in the housing (110) and abutting against an inner wall of an end of the housing (110); a second piston (140) slidingly arranged in the housing (110) between the first piston (100) and the return spring (130) and abutting against the first piston (100) and the return spring (130) at two ends respectively, and provided with a pressure reducing valve (150) for reducing the pressure of the return spring (130).

2. A piston structure according to claim 1, wherein The pressure reducing valve (150) comprises a first valve seat (160) and a first valve core (170), the first valve seat (160) is connected with the second piston (140), the first valve seat (160) has a first through hole (180), and the first valve core (170) has a pressure reducing hole (190) for oil passing; when the second piston (140) compresses the return spring (130), hydraulic oil in the housing (110) pushes the first valve core (170) away from the first valve seat (160) to make the first through hole (180) open for oil passing; when the return spring (130) pushes the second piston (140) to reset, the hydraulic oil in the housing (110) pushes the first valve core (170) towards the first valve seat (160) to make the first valve core (170) close the first through hole (180).

3. A piston structure according to claim 2, wherein The first valve core (170) is further provided with first filter sheets (200), and the first filter sheets (200) are at least provided with two, the first filter sheets (200) are arranged at two ends of the pressure reducing hole (190) respectively, and the first filter sheets (200) are used for blocking hydraulic oil splashing through the pressure reducing hole (190).

4. A piston structure according to claim 2, wherein The pressure reducing valve (150) further comprises a first sliding sleeve (210) slidingly arranged in the first through hole (180), the first valve core (170) comprises a core portion (220) and a cover portion (230), the core portion (220) is connected with an inner wall of the first sliding sleeve (210), the cover portion (230) is used for covering and sealing the first through hole (180), and an outer wall of the first sliding sleeve (210) and an inner wall of the first through hole (180) have a first oil channel (240) communicating two ends of the first through hole (180) therebetween.

5. A piston structure according to claim 4, wherein The outer wall of the first sliding sleeve (210) is polygonal in cross section, and a gap between the outer wall of the first sliding sleeve (210) and the inner wall of the first through hole (180) forms the first oil channel (240).

6. A piston structure according to claim 4, wherein The pressure reducing valve (150) further comprises an outer tooth washer (250) and a locking screw (260), the outer tooth washer (250) is arranged at one end of the first spool (210) away from the first valve core (170), the outer tooth washer (250) has a tooth part abutting and limiting the first valve seat (160), and the locking screw (260) is threadedly connected with the first spool (210) to fix the outer tooth washer (250) at the end of the first spool (210).

7. The piston structure of claim 1 wherein, The first piston (100) and the second piston (140) sequentially divide the inner cavity of the shell (110) into a first oil cavity (270), a second oil cavity (280) and a third oil cavity (290), the reset spring (130) is located in the third oil cavity (290), the second oil cavity (280) and the third oil cavity (290) are communicated through the pressure reducing valve (150), the side wall of the shell (110) has a second oil channel (300) for oil communication between the first oil cavity (270) and the second oil cavity (280), and the side wall of the shell (110) is further provided with a first valve needle (310) for adjusting the oil communication area of the second oil channel (300).

8. A piston structure according to claim 7, wherein The first piston (100) is provided with a one-way valve (320) allowing the hydraulic oil in the second oil cavity (280) to flow to the first oil cavity (270).

9. A piston structure according to claim 8, wherein The one-way valve (320) has a safety valve hole (330), a safety valve bead (340) and a safety valve spring (350), the safety valve hole (330) communicates the first oil cavity (270) and the second oil cavity (280), one end of the safety valve spring (350) abuts against the one-way valve (320), the other end of the safety valve spring (350) abuts against the safety valve bead (340), and the safety valve spring (350) drives the safety valve core to block the safety valve hole (330) from one end of the safety valve hole (330) close to the second oil cavity (280).

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

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