CN110206432B

CN110206432B - Stop-and-fix door closer

Info

Publication number: CN110206432B
Application number: CN201910477752.XA
Authority: CN
Inventors: 朱力克; 聂飞
Original assignee: Suzhou Fuerda Industry Co ltd
Current assignee: Suzhou Fuerda Industry Co ltd
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2024-04-12
Anticipated expiration: 2039-06-03
Also published as: CN110206432A

Abstract

The invention relates to a stationary door closer, comprising: the main shell is internally provided with an inner cavity; the piston is arranged in the inner cavity and connected with a connecting mechanism which is in open-close linkage with the door; a main spring that accumulates door closing energy by the travel of the piston when the door is opened; a first flow path in which a check valve is provided for controlling fluid at the front side in the piston traveling direction to flow to the rear side in the piston traveling direction; the second flow path is provided with a door closing valve, the door closing valve is driven by continuous abutting force to block the second flow path, when the door is stopped at any opening position within a set moving range, fluid pressure difference formed on the front side and the rear side of the piston in the moving direction acts on the door closing valve to form thrust, the thrust and the abutting force are in an opposite state, and when the thrust overcomes the abutting force to move the door closing valve away from the abutting position, the second flow path communicates the front side and the rear side of the piston in the moving direction. Can easily close the door.

Description

Stop-and-fix door closer

Technical Field

The invention relates to a door closer, in particular to a stop type door closer.

Background

In windows or doors of buildings such as houses, apartments, and business buildings, it is sometimes necessary to use a door closer having a spring for storing energy, and the spring stores energy when opening the door; after the external force is released, the spring releases the accumulated energy, so that the aim of automatically closing the door is fulfilled.

In reality, there is a need for a door closer that can stop the door and maintain the door in an open state after the door is opened.

The chinese patent publication No. CN 102191899A discloses a "door closer", the embodiment of which is shown in fig. 6 to 9, which is capable of stopping the door at any one of the open positions, which closes the door with a closing force applied to the door by a human hand, but which has drawbacks: in the state shown in fig. 8, when a person applies a door closing force to the door, the right oil pressure applied to the check valve 40 increases significantly to increase the urging force with which the piston rod 38A can urge the check valve 40, or simply requires a larger and quicker force to close the door.

The chinese patent publication No. CN 87 2 14794U discloses a "delayed automatic door closer with positioning function", which is capable of stopping a door at a large angle, but which also has the disadvantage of requiring a large force to close the door: when a door closing force is applied to the door so that the oil pressure is larger than the tension of the spring 4, the oil flows back to the oil cavity 5 through the end face of the rubber ring of the valve body 10 in the valve body group, but the spring 4 is a main door closing spring, and larger force is needed to overcome the spring 4 to conduct the valve body 10.

Improvements are therefore needed.

Disclosure of Invention

The invention aims to provide a stationary door closer which can close a door more easily.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the invention provides a stationary door closer, comprising:

the main shell is internally provided with an inner cavity;

the piston is arranged in the inner cavity and is connected with a connecting mechanism which is in open-close linkage with the door;

a main spring that accumulates door closing energy by the travel of the piston when the door is opened;

a first flow path in which a check valve for controlling a flow of fluid at a front side in a piston traveling direction to a rear side in the piston traveling direction is provided;

a second flow path in which a door closing valve is provided, the second flow path being configured to communicate front and rear sides of the piston in a traveling direction, and to maintain a fluid pressure difference between the front and rear sides of the piston in the traveling direction when the door is stopped at an arbitrary open position within a set range of motion, thereby maintaining a stopped state of the piston; and releasing the door closing valve by utilizing the pressure difference in the fluid where the door closing valve is positioned.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

when the door is in a stop state, the stop door closer pushes the door to enable the pressure difference of fluid at the front side and the rear side of the piston in the advancing direction to be increased, the pressure difference in the fluid where the door closing valve is positioned is increased, the door closing valve is released through the pressure difference in the fluid where the door closing valve is positioned, the closing trend of the door closing valve cannot be increased due to the pressure difference increase in the fluid where the door closing valve is positioned, and therefore the door closing valve can be released more easily, and the door closing is easier.

The invention also provides a stationary door closer comprising:

the main shell is internally provided with an inner cavity;

a second flow path in which a door closing valve is provided, the second flow path being configured to communicate front and rear sides of the piston in a traveling direction, the second flow path being blocked by a pressing force applied to the door closing valve, and when the door is stopped at an arbitrary open position within a set range of motion, a fluid pressure difference between the front and rear sides of the piston in the traveling direction is maintained to maintain a stopped state of the piston; and utilizing the pressure difference in the fluid where the door closing valve is positioned to form thrust, and releasing the door closing valve when the thrust overcomes the abutting force.

when the door is in a stop state, the stop door closer pushes the door to be closed, so that the pressure difference in the fluid where the door closing valve is positioned is increased, the thrust is increased, when the thrust overcomes the abutting force, the door starts to be closed, and the abutting force cannot be increased due to the increase of the pressure difference in the fluid where the door closing valve is positioned, so that the door can be easily closed.

The invention also provides an optimization scheme:

preferably, a rack is arranged on the piston, a pinion is meshed with the rack, and the pinion is connected with the coupling mechanism.

Optimally, the abutment force is not generated by the main spring.

Preferably, the abutment force is generated by an elastic member.

Optimally, the abutment force is an adjustable setting.

Preferably, it further comprises a third flow path which is blocked when the piston travels to a set position, the third flow path being for connecting front and rear sides of the piston traveling direction.

Further, a positioning opening is provided at a front end of the third flow path with respect to a forward traveling direction of the piston, and the piston blocks the positioning opening to block the third flow path when the piston travels to the set position.

Further, when the piston moves to the moment of shielding the positioning opening, the opening angle of the door is 75-85 degrees.

Further, the set position extends continuously in the piston travel direction for a certain length.

Further, the third flow path and the second flow path have overlapping portions.

Further, the third flow path is provided with at least one communication port which is distributed in front and rear with respect to the rear end of the piston in the forward traveling direction.

Drawings

Some specific embodiments of the invention will be described in detail hereinafter by way of example and not by way of limitation with reference to the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts or portions. It will be appreciated by those skilled in the art that the drawings are not necessarily drawn to scale. In the accompanying drawings:

FIG. 1 is a schematic view of a stationary door closer according to embodiment 1 of the present invention mounted on a door and a door frame;

FIG. 2 is a cross-sectional view of the door closer of the embodiment of FIG. 1 with the door in a closed condition;

FIG. 3 is a cross-sectional view of the embodiment door closer of FIG. 1 with the door being opened;

FIG. 4 is a cross-sectional view of the embodiment door closer of FIG. 1 with the door being closed;

FIG. 5 is a cross-sectional view of the embodiment door closer of FIG. 1 with the door stopped in an open position;

FIG. 6 is a cross-sectional view of the door closer of the embodiment of FIG. 1, with the door manually closed, the door being closed from a rest position;

fig. 7 is a stationary door closer according to embodiment 2 of the present invention, with the addition of a release unit for releasing a door closing valve on the basis of embodiment 1;

FIG. 8 is another state diagram of FIG. 7, with the door closing valve released by the releasing unit;

fig. 9 is a sectional view of a stationary door closer according to embodiment 3 of the present invention, in which a release unit is added to the embodiment 1, the release unit releasing the action of the second flow path by another means;

fig. 10 is another state diagram of fig. 9, in which the release means opens the fourth flow path to release the action of the second flow path;

FIG. 11 is a cross-sectional view of a stationary door closer according to embodiment 4 of the invention, wherein a second flow path is provided in the piston;

FIG. 12 is an enlarged schematic view of the left end wall of the piston of FIG. 11;

FIG. 13 is a schematic view of a door closing valve and its nearby components in yet another alternative, wherein the door closing valve blocks the second flow path but is not continuously subject to a tightening force;

FIG. 14 is a schematic diagram of a door closer converted to have a time delay door closing function;

wherein reference numerals are as follows:

1. a door closer;

2. a main housing;

3. a coupling mechanism;

4. a first arm;

5. a second arm;

6. a second valve chamber;

7. an inner cavity;

8. a piston;

9. a main spring;

10. a pinion gear;

11. a gear shaft;

12. a one-way valve;

13. a first flow path;

14. a first valve chamber;

15. a second flow path;

16. a door closing valve;

17. a small spring;

18. a rack;

19. a third flow path;

20. positioning the opening;

21. a communication port;

22. a release unit;

23. a push rod;

24. a conductive coil;

25. a fourth flow path;

26. a first chamber;

27. a second chamber;

28. an adjusting block;

A. a door;

B. a door frame opening;

C. and a door frame.

Detailed Description

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

Example 1

As shown in fig. 1, the door closer 1 is mounted on a door a and a door frame C, the door a being provided at a door frame opening B and hinged to a side of the door frame C. The main housing 2 of the door closer 1 is mounted on the door a and the coupling mechanism 3 is connected to the upper lintel of the door frame C. The coupling mechanism 3 comprises a first arm 4 and a second arm 5. One end of the second arm 5 is hinged with the upper lintel of the door frame C, the other end of the second arm 5 is hinged with one end of the first arm 4, and the other end of the first arm 4 is hinged with the main shell 2.

As shown in fig. 2, in practice, the other end of the first arm 4 is fixed to the gear shaft 11.

As shown in fig. 2, the door closer 1 comprises a main housing 2, an inner cavity 7 is arranged in the main housing 2, and a piston 8 is slidably arranged in the inner cavity 7. The inner cavity 7 is filled with fluid, the fluid is hydraulic oil, and in other technical schemes, the fluid can also be inert gas. The inner cavity 7 is in a sealed state, so that hydraulic oil is not lost.

The side wall of the piston 8 is provided with a rack 18, a pinion 10 meshed with the rack 18, a gear shaft 11 is integrally arranged on the pinion 10, and the gear shaft 11 is fixed with the first arm 4 (see fig. 1), namely, the pinion 10 is linked with a door through the linking machine 3.

The left end wall of the piston 8 is provided with a first flow path 13, and the left and right ends of the first flow path 13 are connected with the left and right sides of the left end wall of the piston 8. The first flow path 13 is provided with a first valve chamber 14, and the first valve chamber 14 is provided with a check valve 12, and the check valve 12 controls hydraulic oil to flow only from the right side to the left side of the left end wall of the piston 8. The first flow path 13 may not be provided in the piston 8, and the primary function of the first flow path 13 is to communicate the fluid in the front and rear side inner chambers 7 in the traveling direction (traveling to the right) of the piston 8, and therefore, the first flow path 13 may be provided in the main casing 2 or formed between the piston 8 and the inner wall of the main casing 2.

A main spring 9 is arranged between the left end wall of the piston 8 and the right side wall of the main shell 2, and two ends of the main spring 9 are not connected with the piston 8 and the inner wall of the main shell 2, but are compressed and abutted between the left end wall of the piston 8 and the right side wall of the main shell 2.

A second flow path 15 is also provided in the main casing 2, and the second flow path 15 is used for communicating the front and rear side inner cavities 7 of the piston 8 when the piston 8 travels (travels to the right). The second flow passage 15 is provided with a second valve chamber 6, and the second valve chamber 6 is provided with a door closing valve 16. The door closing valve 16 is abutted against the left end opening of the second valve chamber 6 by the continuous abutting force of the small spring 17, thereby blocking the second flow path 15. The closing valve 16 is in a continuous closed state, i.e. the second flow path 15 is in a continuous blocked state.

In this case, the abutment force exerted by the door closing valve 16 is generated by an elastic member, i.e. a small spring 17, and in other embodiments, the abutment force may be generated by other means, such as by the gravity of the door closing valve 16 itself, where the door closing valve 16 may be placed on the opening of the second flow path 15 facing the inner cavity 7, or where a weight member may be applied to the door closing valve 16 to increase the abutment force exerted by the door closing valve 16.

In other embodiments, the closing valve 16 may not bear the pressing force when blocking the second flow path 15, for example, as shown in fig. 13, the closing valve 16 is naturally blocked in the second flow path 15, and when the closing valve 16 moves to the right by a small distance under the action of the pushing force formed by the pressure difference, the closing valve contacts the small spring 17 and is pressed by the small spring 17, which has the beneficial effect that the small spring 17 is not continuously pressed and the service life is prolonged when the door is in the closed state.

As shown in fig. 2, a third flow path 19 is further provided in the main casing 2, and the third flow path 19 is used to communicate with the front and rear side inner chambers 7 of the piston 8 when the piston 8 travels (travels to the right).

The third flow path 19 has a positioning opening 20 at the right end, and the left and right positions of the positioning opening 20 are set in advance.

The second flow path 15 and the third flow path 19 have overlapping portions, thereby making the door closer more miniaturized. The flow path overlapping portion passes through the pinion gear 10 to lubricate the pinion gear 10.

Three communication ports 21 are provided at the left end of the overlapping portion of the second flow path 15 and the third flow path 19, and the three communication ports 21 are distributed in the left-right direction (the front-rear direction in which the piston 8 travels) for varying the opening and closing speeds.

As shown in fig. 3, the door is manually opened. The door acts on the gear shaft 11 through the first arm 4 in the coupling mechanism 3 (see fig. 1), the gear shaft 11 rotates the pinion 10 clockwise, and the pinion 10 moves the rack 18 engaged with the pinion 10 rightward, thereby moving the piston 8 rightward. At this time, the check valve 12 is in an open state, and the hydraulic oil flows from the first chamber 26 on the front side in the traveling direction of the piston 8 into the second chamber 27 on the rear side in the traveling direction of the piston 8 through the first flow path 13. When the piston 8 moves, the main spring 9 is continuously compressed and stores the door closing energy.

As shown in fig. 3, if the piston 8 has traveled rightward, the positioning opening 20 of the third flow path 19 is not yet blocked. In this case, as shown in fig. 4, when the door opening power is removed, the door closing energy accumulated in the main spring 9 is released to apply a leftward force to the piston 8. The check valve 12 blocks the first flow path 13, and the hydraulic oil in the first chamber 26 flows to the second chamber 27 through the third flow path 19. The piston 8 is reversed to the left until the initial position (corresponding to the door fully closed state), and the door is slowly closed due to the restriction of the third flow path 19.

As shown in fig. 5, when the piston 8 moves rightward during door opening, the positioning opening 20 of the third flow path 19 is blocked, and the third flow path 19 is blocked. When the door opening power is removed, the door closing energy accumulated by the main spring 9 has a release trend to apply a leftward acting force to the piston 8, the check valve 12 blocks the first flow path 13, the first chamber 26 is not communicated with the second chamber 27, a negative pressure is formed in the first chamber 26, a positive pressure is formed in the second chamber 27, and a rightward acting force formed by the differential pressure of the first chamber 26 and the second chamber 27 acting on the piston 8 is opposite to the leftward acting force of the main spring 9 on the piston 8, so that the piston 8 is kept stationary, and the door is kept in a stationary state. And the rightward force exerted by the pressure difference on the piston 8 is greater than the leftward force exerted by the main spring 9 on the piston 8 to counter the disturbance of the door by a slight external force such as wind.

As shown in fig. 6, the pressure difference between the first chamber 26 and the second chamber 27 forms a rightward pushing force against the door closing valve 16 through the second flow path 15, and the pushing force is in a state of being opposed to the leftward urging force of the small spring 17 against the door closing valve 16. If a closing force is applied to the door, the differential pressure between the first chamber 26 and the second chamber 27 is further increased, and the rightward pushing force of the differential pressure acting on the closing valve 16 is further increased until the pushing force moves the closing valve 16 away from the closed position (the closing valve 16 moves rightward) against the urging force of the small spring 17 against the closing valve 16, the second flow path 15 is communicated to form a passage, the second flow path 15 communicates the first chamber 26 and the second chamber 27, and hydraulic oil in the second chamber 27 flows through the second flow path 15 to the first chamber 26 by the differential pressure. The piston 8 is reversed to the left and the door is closed.

When the piston 8 is reversed to the left to release the shielding of the positioning opening 20, as shown in fig. 4, the closing valve 16 again blocks the second flow path 15, if the closing power is removed, hydraulic oil flows from the second chamber 27 to the first chamber 26 through the third flow path 19, the piston 8 slowly moves to the left under the pushing action of the main spring 9, and the door slowly closes.

In this case, the main casing 2 is provided with an adjusting block 28, and the small spring 17 is abutted between the adjusting block 28 and the door closing valve 16. The left and right positions of the adjusting block 28 are adjustable, for example, the adjusting block 28 is in threaded connection with the main casing 2, so that the force of the small spring 17 for abutting against the door closing valve 16 is adjustable, that is, the abutting force of the small spring 17 against the door closing valve 16 is adjustable. Thus, the door closing force required after the door is stopped can be adjusted. And further the door closer can be converted into a door closer with an automatic time delay door closing function: as shown in fig. 14, the urging force of the small spring 17 against the door closing valve 16 is further reduced (the adjusting block 28 is further moved to the right), when the piston 8 is moved to the rightmost end after the door is opened (the door is opened to the maximum amplitude), the door opening power is removed, and no door closing power is applied, so that the compressed main spring 9 generates a leftward acting force on the piston 8, the urging force to the right formed by the differential pressure in the fluid where the door closing valve 16 is located overcomes the urging force of the small spring 17, so that the door closing valve 16 is slightly moved to the right only by a small distance, hydraulic oil flows from the left side to the right side of the door closing valve 16 at a small flow, and the door is slowly closed. The abutment force of the small spring 17 is adjusted so that the flow through the door closing valve 16 is small enough that the piston 8 is reversed from the rightmost position to the left until the positioning opening 20 is uncovered for a sufficient time so that the door is closed slowly enough to achieve the effect of automatic time-lapse door closing.

The left and right positions of the positioning opening 20 are set, when the piston 8 moves rightwards to the moment of shielding the positioning opening 20, the opening angle of the door is 75-85 degrees, the door can be stopped after door opening power is removed, and the piston 8 continues to move rightwards to any position and stops, so that the door can be stopped. The door may therefore be substantially stopped in a range of greater than 75 deg. -85 deg. to 90 deg.. The angular range over which the door can be stopped is adjusted by adjusting the left and right positions of the positioning opening 20.

If the position of the piston 8 is the set position when the piston 8 shields the positioning opening 20, in this example, the set position extends a certain length in the traveling direction of the piston 8, and after the piston 8 travels to the instant when the positioning opening 20 is shielded, the positioning opening 20 is always in a shielded state when the piston 8 continues to travel. The door can then be stopped in any open position within the set range of motion. The set range, i.e. the range between the position at which the door is open at the moment the piston 8 travels to block the positioning opening 20 and the complete opening of the door.

In other embodiments, the third flow path 19 may not be provided, and the door may be stopped at an arbitrary door open position.

Example 2

As shown in fig. 7, in embodiment 2, a removing unit 22 is added to embodiment 1, and the same parts as those in embodiment 1 are denoted by the same reference numerals. The release unit 22 is used to release the door closing valve 16.

The release unit 22 includes a push rod 23 and a power member, i.e., a conductive coil 24, for pushing the push rod 23. The push rod 23 has magnetism and is disposed in the conductive coil 24. When the conductive coil 24 is energized, the magnetic field generated by the conductive coil 24 acts on the push rod 23 to push the push rod 23 forward to press the small spring 17, thereby applying a continuous abutting force to the door closing valve 16. The door closer functions in this case as in example 1.

As shown in fig. 8, when the conductive coil 24 is de-energized, the magnetic field of the conductive coil 24 is released, and the push rod 23 releases the abutting force against the door closing valve 16, so that the door closing valve 16 moves rightward due to the rightward pushing force caused by the pressure difference in the second flow path 15, and the door closing valve 16 fails, i.e., the door closing valve 16 is released. At this time, the door is released from the stopped state, and the door is slowly closed. By de-energizing the conductive coil 24, the door can be closed without the use of a human hand to close the door. And the conductive coil 24 may be de-energized at any time as needed, so that control is performed to close the door at any time.

The small spring 17 between the door closing valve 16 and the front end of the push rod 23 plays a certain role in buffering and protecting the door closing valve 16. When the push rod 23 is retracted, the abutment of the small spring 17 against the door-closing valve 16 is also released.

The current and voltage in the conductive coil 24 can be adjusted, and the force of the push rod 23 against the small spring 17 can be adjusted, so that the door closing force or automatic delay door closing function required after the door is stopped can be adjusted by adjusting the left and right positions of the adjusting block 28 in the embodiment 1.

Example 3

As in embodiment 3 shown in fig. 9, the removal unit 22 is provided as well, and the same parts as those of embodiment 1 are given the same reference numerals. Unlike embodiment 2, the release unit 22 does not directly act on the door closing valve 16, but acts on the additional fourth flow path 25, and the additional fourth flow path 25 is engaged with the release unit 22.

The fourth flow path 25 is provided in the main casing 2 and connects the front and rear side chambers 7 in the traveling direction of the piston 8. The release unit 22 includes a push rod 23 and a power member, i.e., a conductive coil 24, for pushing the push rod 23. The push rod 23 has magnetism and is disposed in the conductive coil 24. When the conductive coil 24 is energized, a magnetic field generated by the conductive coil 24 acts on the push rod 23 to advance the push rod 23 into the fourth flow path 25, blocking the fourth flow path 25. The door closer functions in this case as in example 1.

As shown in fig. 10, when the conductive coil 24 is de-energized, the magnetic field of the conductive coil 24 is released, and the push rod 23 is pushed back by the force formed by the pressure difference in the fourth flow path 25, so that the fourth flow path 25 is turned on, and the action of the second flow path 15 is released, that is, the action of controlling the flow of hydraulic oil by the second flow path 15 and the gate valve 16 in the second flow path 15 is released. At this time, the door is released from the stopped state, and the door is slowly closed. By de-energizing the conductive coil 24, the door can be closed without the use of a human hand to close the door. And the conductive coil 24 may be de-energized at any time as needed, so that control is performed to close the door at any time.

Example 4

As shown in fig. 11, embodiment 4 differs from embodiment 1 mainly in the position of the second flow path 15. The second flow path 15 is provided in the main casing 2 in embodiment 1, and in this embodiment, the second flow path 15 is provided in the piston 8, as shown in detail in fig. 12. The resulting advantage is that the closing valve 16 is able to receive a change in pressure differential across the second flow path 15 faster, thereby responding to a closing motion faster.

The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the present invention and to implement the same, but are not intended to limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of the present invention.

Claims

1. A stationary door closer, comprising:

a main shell (2), wherein an inner cavity (7) is arranged in the main shell (2);

the piston (8) is arranged in the inner cavity (7), and the piston (8) is connected with the connecting mechanism (3) which is in open-close linkage with the door;

a main spring (9), the main spring (9) accumulating door closing energy by the travel of the piston (8) when opening the door;

a first flow path (13), wherein a one-way valve (12) is arranged in the first flow path (13), and the one-way valve (12) is used for controlling fluid at the front side of the travel direction of the piston (8) to flow to the rear side of the travel direction of the piston (8);

a second flow path (15), wherein a door closing valve (16) is arranged in the second flow path (15), the second flow path (15) is used for communicating the front side and the rear side of the travelling direction of the piston (8), the second flow path (15) is blocked by the abutting force born by the door closing valve (16), and when the door is stopped at any opening position within a set movable range, the fluid pressure difference of the front side and the rear side of the travelling direction of the piston (8) is maintained, so that the stopped state of the piston (8) is maintained; -creating a thrust by means of a pressure difference in the fluid in which the door closing valve (16) is located, releasing the door closing valve (16) when the thrust overcomes the abutment force;

a rack (18) is arranged on the piston (8), a pinion (10) is meshed with the rack (18), and the pinion (10) is connected to the coupling mechanism (3);

the piston also comprises a third flow path (19), wherein the third flow path (19) is blocked when the piston (8) moves to a set position, and the third flow path (19) is used for connecting the front side and the rear side of the moving direction of the piston (8);

a positioning opening (20) is formed in the front end of the third flow path (19) in the forward traveling direction relative to the piston (8), and the positioning opening (20) is blocked by the piston (8) to block the third flow path (19) when the piston (8) travels to the set position;

a second valve chamber (6) is arranged in the second flow path (15), a door closing valve (16) is arranged in the second valve chamber (6), and the door closing valve (16) is abutted against the left end opening of the second valve chamber (6) under the action of the continuous abutting force of a small spring (17), so that the second flow path (15) is blocked.

2. The stationary door closer of claim 1, wherein: the abutment force is not generated by the main spring (9).

3. The stationary door closer of claim 1, wherein: the abutment force is generated by deformation of the elastic member.

4. The stationary door closer of claim 1, wherein: the abutting force is adjustable.

5. The stationary door closer of claim 1, wherein: when the piston (8) moves to the moment of shielding the positioning opening (20), the opening angle of the door is 75-85 degrees correspondingly.

6. The stationary door closer of claim 1, wherein: the set position extends continuously in the direction of travel of the piston (8) for a certain length.

7. The stationary door closer of claim 1, wherein: the third flow path (19) and the second flow path (15) have overlapping portions.