Large grinder automatic door

Abstract

The present application relates to a large grinder automatic door, including door, cylinder for driving door, two-position four-way throttle valve for switching cylinder pressure, three-position five-way solenoid valve for gas circuit reversing, oil cylinder buffer for near end point area buffering, and gas source device for providing pressure gas, door linear movement connection type is connected to the frame of door, one or more than one block is fixedly connected on the door, in the process of moving in the door, the automatic switching of two-position four-way throttle valve working state is carried out through the corresponding block and two-position four-way throttle valve in the set position / region, and the cylinder pressure is automatically adjusted, the buffering is realized through the action of the corresponding block and the oil cylinder piston rod of the oil cylinder buffer, and the stepless variable resistance / speed is realized through the internal structure of the two-position four-way throttle valve. The present application helps to avoid or reduce the adverse consequences caused by sharp change of speed, and the structure is simple and the operation is simple.

Description

Technical Field

[0001] This invention relates to an automatic door for a large grinding machine controlled by a pneumatic-hydraulic linkage terminal valve group. Background Technology

[0002] The automatic door of a large grinding machine uses a cylinder as the power source for drive / control. The piston rod of the cylinder is connected to the door, driving it in a linear reciprocating motion to open and close. The main body of the door can be inverted L-shaped, with an inwardly extending top plate. A guide structure (e.g., rails, guide grooves) is installed on the frame for mounting the door, engaging with rollers. Several upper and lower rollers support the door on corresponding rails, reducing movement resistance. Lateral balancing rollers can be added as needed to provide lateral support and maintain the door's normal posture. The air source for the cylinder is connected to the corresponding chamber through a corresponding air supply pipe / pneumatic circuit, creating a pressure difference on both sides of the piston, which serves as the power to drive the door. Since the air source pressure is usually constant / stable, the power and speed output of the cylinder are also fixed. Therefore, abrupt speed changes occur during start-up and shutdown, causing severe impact on the equipment and potentially catching nearby personnel off guard, creating a safety hazard.

[0003] One method for achieving different power / speed outputs from a cylinder is to set up two pneumatic circuits with different resistances, or in other words, to set up two parallel (connected) branches with different resistances in the pneumatic circuit, and to use a suitable two-position / multi-position solenoid valve to switch between the different circuits / branches so as to create different pressure differences on both sides of the piston. For example, Chinese patent document CN113735424A discloses a secondary pressing press and its control method. Its main features include: an electromagnetic cylinder, a second proximity switch, a first electromagnetic directional valve, an intermediate proximity switch, a second electromagnetic directional valve, a first throttle valve, a check valve, and a second throttle valve. One output end of the first electromagnetic directional valve is connected to one end of the electromagnetic cylinder, and the other output end is connected to the other end of the electromagnetic cylinder via the second throttle valve and the parallel second electromagnetic directional valve, the first throttle valve, and the check valve. The intermediate proximity switch is located between the second proximity switch and the first proximity switch. The intermediate proximity switch can be arbitrarily set to a starting point. When the magnetic ring in the electromagnetic cylinder passes through the intermediate proximity switch and energizes it, the built-in program of the PLC control system controls the second electromagnetic directional valve to be in a closed state, adjusts the first throttle valve to reduce the downward speed of the electromagnetic cylinder within a certain range, and the mold connected to the electromagnetic cylinder also moves slowly, reducing the impact pressure on the mold. Other control ranges can accelerate the running speed and shorten the overall running time. This prior art can effectively switch between different outputs, helping to improve the movement characteristics of the gate. However, this switching method is step-like, or stepped, and still creates a certain impact, and may even produce a relatively obvious air hammer effect. Summary of the Invention

[0004] To overcome the aforementioned deficiencies of the prior art, the present invention provides a pneumatic-hydraulic linkage terminal control device adapted to the automatic door of a large grinding machine, and also provides an automatic door for a large grinding machine using such a control device, so as to realize stepless speed regulation of the door and avoid or reduce the adverse consequences caused by rapid speed changes.

[0005] The technical solution of this invention is: an automatic door for a large grinding machine, comprising: The door (or door body) is connected to the door frame (the frame or corresponding part of the frame used to set the door) by a linear sliding connection (a movable connection that allows the door to move linearly relative to the frame) and one or more stops are fixedly connected to the door. A cylinder is a door drive device. Its piston rod moves in the same direction as the door. The outer end of the piston rod is connected to the door (including direct connection and connection through connectors / connection assemblies), thereby driving the door to move together. A two-position (or two-way) four-way throttle valve (or two-position four-way continuously variable throttle valve) is used to switch between throttling and non-throttling states of the connected pipeline. It has two plunger valve units, two air source side interfaces (which can be referred to as the first air source side interface and the second air source side interface, respectively), and two cylinder side interfaces (which can be referred to as the first cylinder side interface and the second cylinder side interface, respectively). Each plunger valve unit includes a plunger (which can be referred to as an adjusting plunger) and a valve sleeve (which can be referred to as a speed regulating valve sleeve) that mates with the plunger. The rear end of the plunger (with the direction of the plunger's extension considered forward, and the opposite direction considered backward) is inserted into the valve sleeve, engaging with the valve sleeve... A gap (usually annular gap) is left between the inner walls of the plunger to form a throttling channel (or throttling gap). The front end of the plunger protrudes outside the valve sleeve. The middle of the valve sleeve has two valve sleeve through holes (or valve sleeve inlet and outlet, which can be the first valve sleeve through hole / first valve sleeve inlet and outlet and the second valve sleeve through hole / second valve sleeve inlet and outlet, respectively) penetrating the side wall of the valve sleeve. The circumferential surface (or side surface, or cylindrical surface) of the plunger is provided with a plunger sealing ring (usually an annular sealing ring) for sealing with the inner wall of the valve sleeve. The plunger sealing ring is located in front of the valve sleeve through hole (located in front of the valve sleeve through hole throughout the entire stroke range of the plunger). The first air source side interface (inner end of the interface) and the first cylinder side interface (inner end of the interface) are respectively connected to the first plunger valve unit (any plunger valve unit can be used as the first plunger valve unit, and the other plunger valve unit can be used as the second plunger valve unit; the air source side interface connected to the first plunger valve unit is called the first air source side interface, the cylinder side interface connected to the first plunger valve unit is called the first cylinder side interface, the air source side interface connected to the second plunger valve unit is called the second air source side interface, and the cylinder side interface connected to the second plunger valve unit is called the second cylinder side interface). The corresponding valve sleeve through hole on the first cylinder valve unit can be connected to the corresponding cylinder side interface, and the other valve sleeve through hole can be connected to the corresponding air source side interface. The second air source side interface (the inner end of the interface) and the second cylinder side interface (the inner end of the interface) are respectively connected to the corresponding valve sleeve through hole on the second cylinder valve unit. The outer end of the first cylinder side interface is connected (for example, through the corresponding air supply pipe) to the rodless chamber of the cylinder (rodless chamber air inlet). The outer end of the second cylinder side interface is connected to the rod chamber of the cylinder (rod chamber air inlet). The three-position five-way solenoid valve has three air source side interfaces (located in the middle and on both sides) and two cylinder side interfaces (which can be referred to as the first cylinder side interface and the second cylinder side interface, respectively). It is used to switch the connection mode between the two cylinder side interfaces and the three air source side interfaces (the pipelines connected to these interfaces). The first cylinder side interface is connected to the first air source side interface of the two-position four-way throttle valve, the second cylinder side interface is connected to the second air source side interface of the two-position four-way valve, the air source side interface located in the middle is connected to the air supply pipe (pressurized gas interface) of the air source device, and the air source side interfaces located on both sides are connected to the atmosphere. The hydraulic cylinder damper is equipped with a damping cylinder (referred to as the cylinder) and damping oil pipes at both ends connected to the rod chamber and rodless chamber of the damping cylinder, respectively. The movement direction of the piston rod is consistent with the movement direction of the door (including overlapping or parallel), and is used for damping the door in the near-end area in the corresponding direction.

[0006] Preferably, the outer end of the piston rod of the buffer cylinder is provided with an operating element / operating structure that can interact with the corresponding stop block connected to the door (e.g., the outer end of the piston rod, or a collision block provided at the outer end of the piston rod). When the door moves to the corresponding set position, the stop block contacts the operating element / operating structure of the corresponding cylinder buffer, pushing the piston rod of the cylinder to squeeze / move inward, thereby achieving buffering by relying on the resistance of the cylinder. The buffer cylinder is provided with a cylinder spring for pushing its piston rod outward, so that the cylinder piston rod is in an extended state (fully extended state) under normal conditions (when no external force is applied). A one-way throttle valve for the cylinder is provided on the buffer oil pipe.

[0007] Preferably, the throttling direction of the one-way throttle valve of the hydraulic cylinder is the direction of flow from the rodless chamber to the rod chamber (the throttling effect is only for flow from the rodless chamber to the rod chamber, and has no throttling effect for flow from the rod chamber to the rodless chamber). This allows for the reasonable setting of the relative position and shape of the stop block that matches the hydraulic cylinder buffer (when appropriate), so that when the hydraulic cylinder buffer is needed for buffering (for example, when the door moves to a region close to the end point), the corresponding stop block can just push the piston rod of the hydraulic cylinder to move inward, thereby generating the resistance required for buffering.

[0008] The number of hydraulic cylinder buffers can be one or more. When there are multiple hydraulic cylinder buffers, each hydraulic cylinder buffer can be set as a buffer in the same direction, or each can be set as a buffer in two directions, so as to achieve buffering at the opening end and closing end of the door respectively.

[0009] Preferably, a first one-way throttle valve is provided on the connecting pipe between the outer end of the first cylinder side interface of the two-position four-way throttle valve and the rodless chamber of the cylinder; Preferably, a second one-way throttle valve is provided on the connecting pipe between the outer end of the second cylinder-side interface of the two-position four-way throttle valve and the rod chamber of the cylinder. Furthermore, the throttling direction of both the first one-way throttling valve and the second one-way throttling valve is the flow direction from the two-position four-way throttling valve to the cylinder. They only have a throttling effect on the airflow from the two-position four-way throttling valve to the cylinder, and no throttling effect on the airflow from the cylinder to the two-position four-way throttling valve.

[0010] Preferably, the two plungers of the two-position four-way throttle valve are provided with a linkage connection structure (a connection method / structure that enables the two to work together).

[0011] For example, the front ends of two plungers are fixedly connected to the same linkage connector (e.g., a connecting plate, or linkage plate), and linkage is achieved through their fixed connection with the linkage connector.

[0012] Preferably, the two plunger valve units of the two-position four-way throttle valve are disposed on the same throttle valve body.

[0013] A valve sleeve structure (with the same structure as the valve sleeve) can be provided on the throttle valve body to achieve integration of the valve sleeve and the throttle valve body, or an independent valve sleeve can be installed on the throttle valve body.

[0014] For example, the throttle valve body is provided with valve sleeve mounting holes for fixing the plunger valve unit. There are two valve body holes. The valve sleeves of the two plunger valve units are fixedly installed in their respective valve sleeve mounting holes. The throttle valve body is provided with connecting channels that communicate with the valve sleeve through holes on each valve sleeve. The outer end of the connecting channel is provided with a pneumatic connector, which is used as an interface for connecting the corresponding connecting channel / valve sleeve through hole to the external pipeline (including the air source side interface and the cylinder side interface).

[0015] Furthermore, the valve sleeve is sealed to the wall of the corresponding valve sleeve mounting hole, for example, the circumferential surface of the valve sleeve is tightly fitted to the wall of the valve sleeve mounting hole (e.g., interference fit).

[0016] Preferably, the rear end of the plunger is tapered (or frustum-shaped, with its cross-section gradually increasing from the inside to the outside).

[0017] Preferably, the valve sleeve of the plunger unit is provided with a plunger spring that pushes the plunger forward. The plunger spring is located on the rear side of the plunger (with the direction in which the plunger extends being forward and the opposite direction being rear), and the front end of the plunger spring abuts against the rear end face of the plunger.

[0018] The rear end of the plunger spring can be fixed, for example, against the front end face (inner end face) of the valve sleeve cover. Thus, under the action of the plunger spring, the plunger is in an extended state (fully extended state) under normal conditions (when no external force is applied).

[0019] The working state of the two-position four-way throttle valve when the plunger is extended (fully extended) can be set to a non-throttle state, and the state after the plunger is retracted can be set to a throttle state. This allows for the reasonable setting of the shape and relative position of the stop block that matches the two-position four-way throttle valve, so that when the two-position four-way throttle valve needs to throttle (for example, at the end or the first half, the first third, or the first two-thirds of the valve movement), the corresponding stop block can push the plunger to gradually switch from the non-throttle state to the throttle state.

[0020] The plunger of the two-position four-way throttle valve has an operating element / operating structure (e.g., the outer end of the plunger, or a collision block provided at the outer end of the plunger) that can interact with the corresponding stop of the valve. When the valve moves to the corresponding set position, the operating element / operating structure on the two-position four-way throttle valve contacts the corresponding stop, and the plunger moves inward under the push of the stop, thereby realizing the state switching of the two-position four-way throttle valve.

[0021] The cylinder can be controlled in the following way: the pneumatic stroke / cylinder drive stroke is divided into three stages: the beginning stage (or initial segment), the middle stage, and the end stage (or final segment). At the beginning stage, the cylinder is operated at full pressure (normal pressure), or at the beginning stage (e.g., the first half, the first third, or the first two-thirds of the beginning stage), the cylinder is operated at reduced pressure (throttling). At the end stage, the cylinder is operated at full pressure, so that the cylinder output speed continuously increases until it reaches the equilibrium speed (constant speed, under unchanged external conditions) in the middle stage. In the middle stage, the cylinder is operated at full pressure, and the cylinder output speed remains constant. At the end stage, the cylinder operation mode is switched from full pressure operation (also known as switching) to reduced pressure operation, and the cylinder output speed continuously decreases.

[0022] Preferably, the process of switching from full-pressure operation to depressurization operation is a stepless transition, and the cylinder power (pressure difference on both sides of the piston) gradually decreases in a stepless manner.

[0023] Furthermore, the method of switching from full-pressure operation to pressure-reducing operation is to switch the two-position four-way throttle valve from a non-throttle state to a throttle state.

[0024] Preferably, before starting, the two-position four-way throttle valve is set to the throttling state. After the gas source is connected, the two-position four-way throttle valve is activated to switch from the throttling state to the non-throttling state.

[0025] The appropriate stop and two-position four-way throttle valve can be set according to the control method / control requirements of the cylinder, and the cylinder operating pressure can be automatically switched by moving the stop.

[0026] Preferably, the manner of automatically switching the actuation pressure of the air cylinder through the movement of the stopper is as follows: when the air cylinder is controlled at full pressure, the corresponding stopper does not squeeze / push the actuating member / actuating structure of the two-position four-way throttle valve, so that the two-position four-way throttle valve is in a non-throttling state; when the air cylinder is controlled under pressure reduction (throttling), the corresponding stopper squeezes / pushes the actuating member / actuating structure of the two-position four-way throttle valve, so that the two-position four-way throttle valve is in a throttling state; during the process of switching from full pressure control to pressure reduction control or switching from pressure reduction control to full pressure control, the corresponding stopper gradually squeezes / pushes the actuating member / actuating structure of the two-position four-way throttle valve or gradually disengages from the actuating member / actuating structure of the two-position four-way throttle valve, so as to realize the stepless transition of the two-position four-way throttle valve from the non-throttling state to the throttling state or from the throttling state to the non-throttling state.

[0027] The arrangement of the oil cylinder buffer and the corresponding stopper can be carried out according to the buffering requirements for the door, so as to automatically realize the motion buffering of the door in the area near the end point through the movement of the stopper.

[0028] For example, in the buffering stage or the rear section of the buffering stage (the stage close to stopping), the corresponding stopper squeezes and pushes the actuating member / actuating structure of the buffering oil cylinder, so that the piston rod of the oil cylinder performs a retraction movement along with the door; in the non-buffering stage or the non-buffering stage and the front section of the buffering stage (the stage not close to stopping), the corresponding stopper does not contact the actuating member / actuating structure of the buffering oil cylinder.

[0029] Preferably, the stopper matched with the two-position four-way throttle valve is trapezoidal, the main part of its outer edge (the edge facing the two-position four-way throttle valve) is a straight edge parallel to the movement direction of the door, one end of the outer edge (a side edge capable of interacting with the actuating member / actuating structure of the two-position four-way throttle valve) is a bevel edge (a straight bevel edge or a curved bevel edge), the two-position four-way throttle valve is fixed in position (for example, fixedly mounted on the frame of the door), and its axial direction (the axial direction of the plunger) is perpendicular to the movement direction of the door, so that the movable area of the stopper includes the area where the front end of the actuating rod / actuating structure of the two-position four-way throttle valve is located (the area where it is located in the free state). When the stopper is not in front of the two-position four-way throttle valve in the axial direction, the plunger of the two-position four-way throttle valve is not blocked or squeezed by the outside (the stopper), and the plunger extends outward to the position in the non-throttling state under the action of the plunger spring. When the main part of the outer edge of the corresponding stopper moves to the front of the two-position four-way throttle valve in the axial direction, the actuating rod / actuating structure of the two-position four-way throttle valve is squeezed by the main part of the outer edge of the stopper, and the plunger retracts to the position in the throttling state. When the bevel edge at one end of the outer edge of the stopper moves in front of the two-position four-way throttle valve in the axial direction, the squeezing degree of the actuating rod / actuating structure of the two-position four-way throttle valve by the bevel edge of the outer edge of the stopper gradually increases or gradually decreases, so as to realize the transition from the non-throttling state to the throttling state or from the throttling state to the non-throttling state.

[0030] The beneficial effects of this invention are as follows: by using a two-position four-way throttle valve with stepless resistance / speed variation to switch the cylinder air supply pressure, stepless adjustment of cylinder power output and speed output is achieved, avoiding the drastic speed changes under stepped adjustment. At the same time, there is no need to set up two air paths with different resistances (and the corresponding switching of air paths), which simplifies the construction of the control device, saves equipment / hardware costs, simplifies the operation method, and facilitates use and maintenance. Attached Figure Description

[0031] Figure 1 This is a schematic diagram (side view) of the structure of the present invention; Figure 2 This is a schematic diagram (top view) of the invention. Figure 3 This is a schematic diagram of the control device and control principle of the present invention; Figure 4 This is a schematic diagram of the pressure change curve of the cylinder intake chamber according to the present invention; Figure 5 Is Figure 4 A schematic diagram of the cylinder output speed (piston rod outer end speed) variation curve under the relevant operating methods; Figure 6 This is a schematic diagram of a two-position four-way throttle valve according to the present invention; Figure 7 This is a schematic diagram of another two-position four-way throttle valve according to the present invention; Figure 8 This is a schematic diagram showing the action of the stop block that moves with the door and the corresponding operating part of the two-position four-way throttle valve in different relative positions. Detailed Implementation

[0032] See Figure 1 and Figure 2The automatic door 80 of the large grinding machine is linearly connected to the frame 88 for installing the door and the ground foundation (where appropriate). The side view shape (or longitudinal section shape) of the door is usually roughly inverted L-shaped, but other suitable shapes can be used depending on actual needs. The top of the main body of the door (or main door body) is fixedly connected to a top plate (usually a horizontal plate, which can be called a horizontal top plate) 82 by a horizontal or other suitable shaped connecting plate (or connecting frame) 83. The front and rear sides of the top plate (with the door opening direction as the front) are provided with several horizontally arranged upper rollers 85, which are supported by the upper rollers on the corresponding side of the horizontally extending upper roller guide groove (or guide rail). The upper roller guide groove is a U-shaped opening that is laterally (inward). The bottom of the door is provided with several horizontally arranged lower rollers 86, which are supported by the lower rollers on the horizontally extending lower roller guide rail 89. Each roller is mounted on the corresponding side (front or rear) of the bottom surface of the top plate via its own rotating shaft. The rotating shaft extends in the front-to-back direction and can roll in the corresponding upper roller guide groove (or on the guide rail). The lower roller is mounted on the inner side (rear side) of the lower part of the main body of the door via its own rotating shaft. The rotating shaft extends in the front-to-back direction and can roll on the corresponding horizontally extending lower roller track. The upper roller tracks on both the front and rear sides are fixedly mounted on the frame, and the lower roller tracks are fixedly mounted on the ground foundation. With the rolling cooperation of each roller with the corresponding guide groove and guide rail, the door is allowed to move laterally. The top of the main body of the door is equipped with several horizontally arranged lateral balancing rollers 87. These rollers are located above the door and are rotatably mounted on the top of the main body via their respective shafts, which extend vertically. A horizontally extending inverted U-shaped roller guide groove is fixedly installed at the corresponding position on the frame. The lateral balancing rollers are located within the roller guide grooves, with their outer diameter slightly smaller than the width of the groove, allowing them to roll against either side of the inner wall of the guide groove to achieve force / torque balance on the door. Any suitable existing technology can be used to install / connect various rollers, and roller tracks and guide grooves can be configured according to actual needs.

[0033] Alternatively, any other suitable existing technology or other technology can be used to achieve the lateral linear movement connection of the door on the frame.

[0034] Protective covers 81 and other facilities can be installed on the rack according to existing technology.

[0035] The cylinder 30 can be installed on the top of the frame, above the top plate. The outer end of its piston rod 33 is fixedly connected to the top plate through a corresponding connector, so that the door can be moved as a whole through the top plate. The axis of the cylinder is horizontal (the direction of door movement), and the door can be moved back and forth in a linear motion through the extension and retraction of its piston rod.

[0036] A two-position (or two-way) four-way throttle valve with resistance switching (throttling / non-throttling switching) function is used to regulate the pneumatic circuit resistance / cylinder power (pressure difference across the piston). This two-position four-way throttle valve can connect two air supply pipes simultaneously, achieving synchronous regulation of the resistance (throttling and non-throttling) of the two air supply pipes, thus simplifying the air circuit and its control device and method. Existing throttle valves are usually one-position two-way throttle valves used to achieve throttling at corresponding parts in the pipeline. This throttling method is usually bidirectional. When unidirectional throttling is required, a check valve can be connected in parallel with a conventional throttle valve, integrating the parallel check valve and throttle valve together. When switching between conventional connection (also known as non-throttling connection or full connection) and throttling connection (connection under throttling) is required, a shut-off valve needs to be connected in parallel with the conventional throttle valve. The switching between the non-throttling connection and throttling connection states is achieved by controlling the opening and closing of the shut-off valve. When it is necessary to synchronously switch between non-throttling and throttling connections between two pipelines, it is necessary to set up two sets of parallel pipelines with throttling valves and shut-off valves, and to set up a suitable control device to synchronously control the two shut-off valves. Therefore, this method not only leads to complex construction and troublesome control, but also has a relatively high failure rate and maintenance cost.

[0037] See Figure 6 and Figure 7 This two-position four-way throttle valve (or two-position four-way continuously variable speed throttle valve) 10 with resistance switching function can be used to realize synchronous switching / synchronous control between two pipelines in non-throttle connection and throttle connection states, and the switching process is stepless / continuous. This two-position four-way continuously variable speed throttle valve includes two plunger valve units. The plunger valve unit is equipped with a plunger (which can be called an adjusting plunger) 11 and a valve sleeve (which can be called a speed regulating valve sleeve) that cooperates with the plunger. The rear end (or inner end) of the plunger is inserted into the valve sleeve. A gap (usually an annular gap) is left between the circumference of the plunger and the inner wall of the valve sleeve to form a throttle channel (or throttle gap). The front end (or outer end) of the plunger protrudes outside the valve sleeve. The valve sleeve has two through holes (or valve sleeve inlets / outlets) 16 penetrating the sidewall of the valve sleeve, which can be referred to as the first valve sleeve through hole (or first valve sleeve inlet / outlet) and the second valve sleeve through hole (or second valve sleeve inlet / outlet), respectively. The first and second valve sleeve through holes can be aligned (located on the same diameter), or, if necessary, misaligned (e.g., axially misaligned). A plunger sealing ring (usually an annular sealing ring) 12 is provided on the circumferential surface (or side surface, or cylindrical surface) of the plunger for sealing with the inner wall of the valve sleeve. An annular groove for embedding / fixing the sealing ring can be provided on the circumferential surface of the plunger. The plunger sealing ring is located on the front side of the valve sleeve through hole (located on the front side / near the front end of the plunger throughout the entire stroke range of the plunger), sealing the annular gap between the plunger and the valve sleeve to prevent water (or other liquids, the same below) inside the valve sleeve (inside the plunger sealing ring) from leaking out through this gap.

[0038] As a preferred embodiment, the rear end (inner end) 13 of the plunger can be conical (or frustum-shaped, with its cross-section gradually increasing from back to front). Thus, as the plunger moves backward, the degree of obstruction of the non-throttling channel located between the two valve sleeve through holes by the conical plunger (the conical part of the plunger) gradually changes (steplessly changes), thereby the resistance to water flow also gradually changes during the switching process.

[0039] The inner end (the part near the inner end) of the valve sleeve through hole can be a round hole or an elongated hole (the cross-section of the hole is elongated). The length direction of the elongated hole is parallel to the axial direction of the plunger. This shape of the hole helps to gradually change the degree of obstruction of the non-throttling channel by the plunger.

[0040] The rear end of the valve sleeve (the end from which no plunger protrudes) may not have an opening (port); that is, the valve sleeve bore is a blind hole that opens only at the front end. For ease of assembly and internal structure machining, the rear end of the valve sleeve may typically have a port, which is closed by an end cap (or rear cover) 18 fixedly mounted (e.g., threaded connection with a sealing ring) on ​​that port.

[0041] The valve sleeve contains a plunger spring (usually a helical spring) 17, located behind the plunger. The front end of the helical spring, used as the plunger spring, can rest against the rear end face of the plunger, and the rear end can rest against the front end face (inner end face) of the valve sleeve cover. An axial blind hole for inserting the rear end of the spring can be provided on the front end face of the cover to facilitate the fixation / stability of the spring. When the plunger is not subjected to an inward (rearward) external force, the plunger spring pushes the plunger forward away from the rear end of the valve sleeve, creating a space behind the plunger that can accommodate water. This space connects to the two valve sleeve through holes on the valve sleeve, forming a non-throttling channel within the valve sleeve that connects the two valve sleeve through holes. When the plunger is subjected to an inward (rearward) external force, the plunger compresses the plunger spring and moves backward along the orifice of the valve sleeve. The non-throttling channel between the two valve sleeve orifices is blocked by the plunger (the main body of the plunger). Water flowing from one valve sleeve orifice to the other can only pass through the gap between the plunger and the inner wall of the valve sleeve. This annular gap-shaped channel has relatively high resistance and can be called a throttling channel. Therefore, the switching between this non-throttling state and the throttling state can be achieved by changing the position of the plunger.

[0042] A plunger limiting structure should also be provided on the valve sleeve. For example, a limiting ring is screwed onto the port of the valve sleeve hole to limit / block the plunger from disengaging, thereby limiting the maximum forward movement of the plunger. The plunger's circumferential surface has an annular limiting shoulder that mates with the limiting ring. In this state, the plunger spring is usually still under a certain degree of compression to maintain the stability of the plunger.

[0043] The front end (outer end) of the two plungers (the plungers of the two plunger valve unit) is provided with a linkage connection structure (a connection structure / connector that enables the two to move in tandem). The linkage connection structure limits the two plungers to move synchronously, thereby achieving synchronous control of the two plunger valve units.

[0044] The two plungers can be linked by any suitable connection method. For example, the front ends of the two plungers can be fixedly connected to the same linkage connector (e.g., a connecting plate, or linkage plate) 28, so that as long as one plunger moves, the other plunger will also move synchronously.

[0045] The two plungers can be operated by any suitable operating element / operating device, driving and controlling the two plungers to move synchronously, thereby realizing the operation of the two-position four-way throttle valve.

[0046] For example, the outer end (front end) of any plunger can be used directly as an operating element, or a coaxially fixed operating rod 29 can be provided, or an operating rod extending forward can be provided on the connecting plate for linkage connection. Pushing the outer end of the plunger or the operating rod backward causes the two plungers to move backward synchronously, putting the throttle valve in a throttling state. Releasing the outer end of the plunger or the operating rod causes the two plungers to move forward under the action of the plunger spring, putting the throttle valve in a non-throttling state. The stop block 36 can be connected to the outer end of the piston rod 33 (for example, by a fixed push rod / connector to position the stop block appropriately). When the stop block moves to the set position, the operating rod is pushed to achieve switching. When using an electronically controlled operating device to operate / control the status of a two-position four-way throttle valve, a contact switch / proximity switch can be set to cooperate with a stop or similar component / structure. When the piston rod of the cylinder drives the corresponding stop or similar component / structure to move to the set position, the corresponding contact switch / proximity switch is triggered. The control device controls the two-position four-way throttle valve to perform the required state switching based on the signal generated by triggering the contact switch / proximity switch.

[0047] Electromagnetic drive mechanisms can also be used to drive the plunger. The electromagnetic drive mechanism and its control method (control device) can adopt any suitable existing technology, such as existing electromagnetic drive mechanisms and their control methods (control devices) used to drive multi-position solenoid valves / spools.

[0048] Unlike existing multi-position valves used for switching between different connection methods (reversal), this two-position four-way throttle valve maintains the same pipeline connection relationship under different states (throttling and non-throttling states). Both valve sleeve through-holes on the same valve sleeve are connected. For external pipelines, both sections are connected to the two valve sleeve through-holes on the same valve sleeve. In the throttling state, the water passage within the valve sleeve is a throttling channel with significant resistance, resulting in a throttling effect. In the non-throttling state, the water passage within the valve sleeve includes both throttling and non-throttling channels, with very low resistance and no throttling effect.

[0049] A unified valve body 21 can be set, which can be called a throttling valve body. Two plunger valve units are installed / integrated on the throttling valve body to form an integral valve and facilitate the installation of pipe interfaces (joints) and other accessories / components.

[0050] Two valve sleeve mounting holes can be provided on the throttle valve body for fixing and mounting the plunger valve unit. The two valve sleeve mounting holes are usually parallel to each other and have the same or opposite opening directions to facilitate layout under different practical conditions / applications. The valve sleeves (along with the plungers, etc.) of the two plunger valve units can be fixedly mounted (e.g., interference fit, or threaded connection / fastening, etc.) in their respective valve sleeve mounting holes. The circumferential surface of the valve sleeve can be tightly fitted with the hole wall of the valve sleeve mounting hole (e.g., interference fit) to achieve a seal between the valve sleeve and the valve sleeve mounting hole. Depending on the actual installation / fitting method, sealing elements (e.g., sealing rings, sealing gaskets, etc.) can also be provided at appropriate locations to achieve the required seal.

[0051] The throttle valve body has connection channels 26 that communicate with the corresponding valve sleeve through holes on each valve sleeve. The inner port of the connection channel is aligned with the outer port of the corresponding valve sleeve through hole on the valve sleeve. A corresponding pneumatic connector (for connecting an external air supply pipe) 23 is installed on the outer port of the connection channel. External pipes / air supply pipes can be connected to the corresponding pneumatic connectors to form the required pneumatic circuit / pipeline.

[0052] See Figure 3The automatic door control device includes an air source device 50. Its air source (e.g., a combination of an air compressor and an air tank) 51 can be located locally (within the air source device) or can be introduced from an air source located elsewhere via a pressure delivery pipeline. The pressurized gas output of the air source is connected to a filter 52, and after filtration, it is connected to a pressure reducing valve 53. A pressure gauge (air pressure detector) 54 is installed on the output side of the pressure reducing valve to monitor / display the output pressure of the air source device (output interface) in real time. The output of the pressure reducing valve, as the output (output interface) of the air source device, is connected to a three-position five-way solenoid valve 40, which serves as an electromagnetic directional valve, via a corresponding air delivery pipe. This allows the valve to switch the state of the three-position five-way solenoid valve to supply air to the rodless or rod-side chamber of the cylinder 30, or to not supply air to any chamber of the cylinder.

[0053] The three-position five-way solenoid valve has three air source side interfaces (inlet and outlet) and two cylinder side interfaces (inlet and outlet), which are used to switch the connection between the two cylinder side interfaces and the three air source side interfaces. The middle air source side interface 41 is connected to the pressurized gas outlet (or air source port) 58 of the air source device. The air source side interfaces on both sides are open to the atmosphere. For example, they can be connected to a silencer 45 exposed to the atmosphere through a corresponding air supply pipe. After the released airflow passes through the silencer, the gas emission noise can be effectively reduced.

[0054] The two cylinder-side ports of the three-position five-way solenoid valve can be referred to as the first cylinder-side port and the second cylinder-side port, respectively. The two air source-side ports located on either side can be referred to as the first air source-side port and the second air source-side port, respectively. The first air source-side port is the air source-side port that can communicate with the first cylinder-side port. It is connected to the atmosphere through a first silencer to release pressurized gas from the first cylinder-side port into the atmosphere. The second air source-side port is the air source-side port that can communicate with the second cylinder-side port. It is connected to the atmosphere through a second silencer to release pressurized gas from the second cylinder-side port into the atmosphere. A three-position five-way solenoid valve with this connection method can be called a center-venting three-position five-way solenoid valve, and its three operating states can be referred to as the first air supply state, the second air supply state, and the intermediate venting state. In the first air supply state, the first cylinder-side interface is connected to the air source-side interface located in the middle, the second cylinder-side interface is connected to the second air source-side interface, and the first air source-side interface is closed. In this state, pressurized gas is input into the rodless chamber of the cylinder (in the case where the first cylinder-side interface is connected to the rodless chamber interface through an air supply pipe, the same below). The pressure difference on both sides of the piston 32 pushes the piston to move towards the rod chamber, and the piston rod moves outward. The gas in the rod chamber is compressed by the piston movement and continuously discharged into the atmosphere. In the second air supply state, the second cylinder-side interface is connected to the air source-side interface located in the middle. When the cylinder side interface is connected to the first air source side interface and the second air source side interface is closed, pressurized gas is input into the rod chamber of the cylinder. The pressure difference on both sides of the piston pushes the piston to move towards the rodless chamber, and the piston rod moves inward (retracts). The gas in the rodless chamber is compressed by the piston movement and continuously discharged into the atmosphere. In the intermediate venting state, the first cylinder side interface is connected to the first air source side interface, the second cylinder side interface is connected to the second air source side interface, and the air source side interface in the middle is closed. In this state, both the rodless chamber and the rod chamber of the cylinder are connected to the atmosphere, and the pressure is eliminated by venting gas into the atmosphere.

[0055] The two-position four-way throttle valve 10 has two air source side ports and two cylinder side ports, which can be referred to as the first air source side port, the second air source side port, the first cylinder side port, and the second cylinder side port of the two-position four-way throttle valve, respectively. The first cylinder side port is the cylinder side port connected to the first air source side port, and the second cylinder side port is the cylinder side port connected to the second air source side port. This connection relationship does not change due to changes in the working state of the two-position four-way throttle valve. This two-position four-way throttle valve can be used to switch the internal passage between corresponding cylinder side ports and air source side ports. Its first air source side port (either of the two air source side ports can be considered / used as the first air source side port) is connected to the first cylinder side port (either of the two cylinder side ports can be considered / used as the first cylinder side port) of the three-position five-way solenoid valve, and its second air source side port (the other of the two air source side ports) is connected to the second cylinder side port (the other of the two cylinder side ports) of the three-position five-way solenoid valve.

[0056] The cylinder, as a power source / drive device, outputs power (e.g., power output, speed output) through the outer end of the piston rod. Its rodless chamber interface (the inlet / outlet / port connecting the rodless chamber) is connected to the first cylinder side interface of the two-position four-way throttle valve (the cylinder side interface of the two-position four-way throttle valve that is connected to the first air source side interface), and the rod chamber interface (the inlet / outlet connecting the rod chamber) is connected to the second cylinder side interface of the two-position four-way throttle valve (the cylinder side interface of the two-position four-way throttle valve that is connected to the second air source side interface).

[0057] A one-way throttle valve 38 is connected in series on the connecting pipe between the rodless chamber interface of the cylinder and the first cylinder side interface of the two-position four-way throttle valve, and on the connecting pipe (air supply pipe) between the rod chamber interface of the cylinder and the second cylinder side interface of the two-position four-way throttle valve. A speed control valve 39 may or may not be connected in series for corresponding adjustment. The one-way throttle valve and the speed control valve may be connected in series in the middle of the corresponding air supply pipe 19, or they may be connected in series at either end of the corresponding air supply pipe (including the interface connected to either end of the corresponding air supply pipe, such as the corresponding interface of the cylinder or the corresponding interface of the two-position four-way throttle valve). For example, the one-way throttle valve can be set at the corresponding interface of the two-position four-way throttle valve and fixedly installed together with the two-position four-way throttle valve. The speed control valve can be set at the corresponding interface of the cylinder and fixedly installed together with the cylinder. These two one-way throttle valves can be referred to as the first one-way throttle valve (the one-way throttle valve on the connecting pipe between the rodless chamber port of the cylinder and the first cylinder side port of the two-position four-way throttle valve) and the second one-way throttle valve (the one-way throttle valve on the connecting pipe between the rod chamber port of the cylinder and the second cylinder side port of the two-position four-way throttle valve). The throttling direction of both the first and second one-way throttle valves is from the two-position four-way throttle valve to the cylinder (they only throttle the gas flow from the two-position four-way throttle valve to the cylinder). Thus, when supplying gas to the cylinder cavity (rodless chamber or rod chamber), the corresponding one-way throttle valve throttles the gas to form the required pressure. When the cylinder cavity exhausts gas to the atmosphere, it is not subject to the throttling resistance of the one-way throttle valve.

[0058] The above-mentioned multiple valves and their corresponding connection channels (when appropriate) can be integrated together to form a control valve group 91 for the convenience of the user.

[0059] A matching control device / controller 90 can be set up according to existing technology to control various solenoid valves and other electromagnetic facilities, receive signals / data collected by pressure sensors (pressure gauges) and position sensors, and perform corresponding data processing, equipment control, remote information / data interaction and alarm according to the set method. The control device can be installed on the rack or other suitable locations.

[0060] The hydraulic cylinder buffers 60 are installed near the end positions on both sides of the door, or at suitable positions in the front-to-back direction of the door, to buffer the movement of the door to the corresponding side in the near-end area of ​​the corresponding side. The door is fixedly connected (e.g., via corresponding fixed connecting plates / frames) to a stop block (which can be called a cylinder stop block, and can be block-shaped, rod-shaped, or other suitable shape) that matches each buffer cylinder 61. When the door moves to the near-end area of ​​the corresponding side, the corresponding cylinder stop block presses against the outer end of the piston rod of the corresponding buffer cylinder and pushes the piston rod inward (inside the cylinder) as the door moves. The buffer cylinder applies resistance to the door through the stop block, thus achieving buffering.

[0061] The rod-side and rodless-side chambers of the buffer cylinder (hereinafter referred to as the cylinder) 61 are connected by a buffer oil pipe, and a one-way throttle valve 68 is connected in series on the buffer cylinder. During the inward movement of the piston rod, the piston moves towards the rodless-side chamber, increasing the pressure and decreasing the pressure in the rod-side chamber. The oil in the rodless-side chamber flows to the rod-side chamber through the buffer oil pipe. During this flow, it is subject to the throttling resistance of the one-way throttle valve, maintaining a certain (high) pressure difference on both sides of the piston rod, thus generating the resistance required for buffering. When the valve moves to the other side, causing the cylinder stop to gradually disengage from the piston rod, the piston rod moves towards the rod-side chamber under the action of the spring inside the cylinder. The oil flowing back to the rodless-side chamber through the buffer oil pipe is not subject to the throttling resistance of the one-way throttle valve, and the piston rod can be reset (returned to its fully extended state) without excessive spring force.

[0062] When installing the buffer oil pipe, the movement direction of its piston rod should be consistent with the movement direction of the door (including overlapping or parallel). The outer end of the piston rod is equipped with an operating element / operating structure that can interact with the corresponding stop connected to the door (e.g., the outer end of the piston rod, or a collision block set at the outer end of the piston rod) 69. When the door moves to the corresponding set position, the stop contacts the operating element / operating structure of the corresponding oil cylinder buffer, pushing the piston rod of the oil cylinder to squeeze / move inward, thereby achieving buffering by relying on the resistance of the oil cylinder. The buffer oil cylinder is equipped with an oil cylinder spring for pushing its piston rod outward, so that under normal conditions (when no external force is applied), The piston rod of the hydraulic cylinder is in an extended state (fully extended state). The buffer oil pipe is equipped with a one-way throttle valve for the hydraulic cylinder. The throttling direction of the one-way throttle valve is from the rodless chamber to the rod chamber (the throttling effect is only on the flow from the rodless chamber to the rod chamber, and has no throttling effect on the flow from the rod chamber to the rodless chamber). This allows for the reasonable setting of the relative position and shape of the stop block that matches the hydraulic cylinder buffer (when appropriate), so that when the hydraulic cylinder buffer is needed for buffering (for example, when the door moves to a region close to the end point), the corresponding stop block can push the piston rod of the hydraulic cylinder inward, thereby generating the resistance required for buffering.

[0063] Since hydraulic cylinder buffers are used for buffering in the area near the end point, and the movement of the door is bidirectional, it is usually advisable to set one or a set of hydraulic cylinder buffers in each of the two movement directions. If buffering is not required in one movement direction in practice, one or a set of hydraulic cylinder buffers can be set only in the other movement direction.

[0064] See Figure 4 and Figure 5 The actual driving stroke of the cylinder piston rod can be divided into three stages: the beginning (or initial stage), the middle stage, and the end (or final stage). At the beginning of the stroke, the cylinder can be depressurized and operated first. Figure 4 (not shown in the image), then full pressure operation (pressure under no-throttling conditions, or normal pressure), or all full pressure operation (such as...). Figure 4 As shown in the diagram, the cylinder output speed (piston rod outer end speed) continuously increases until it reaches the equilibrium (constant) speed in the middle section; in the middle section, the cylinder is operated at full pressure, and the cylinder output speed remains constant (under the condition that the relevant external conditions remain unchanged); at the end of the stroke, the cylinder operation mode is switched from full pressure operation (or switching) to depressurization operation (or throttling operation), and the cylinder output speed continuously decreases to achieve the initial acceleration and the braking / buffering deceleration at the end; in the middle section of the stroke, the power output by the cylinder is roughly balanced with the resistance of the system (including the actuator / device driven by the cylinder), achieving a constant speed.

[0065] See Figure 8 The two-position four-way throttle valve and corresponding stops can be arranged according to the control method / control requirements of the cylinder. This ensures that when the cylinder is under full pressure control, the corresponding stops do not compress / push the operating parts / operating structure of the two-position four-way throttle valve, thus keeping the two-position four-way throttle valve in a non-throttling state. When the cylinder is under pressure reduction (throttling) control, the corresponding stops compress / push the operating parts / operating structure of the two-position four-way throttle valve, thus keeping the two-position four-way throttle valve in a throttling state. During the process of switching from full pressure control to pressure reduction control or vice versa, the corresponding stops gradually compress... The two-position four-way throttle valve's operating mechanism / operating structure is pushed or gradually disengaged from the valve's operating mechanism / operating structure, enabling stepless switching between non-throttling and throttling states. During the buffering phase or the later part of the buffering phase (near the stop), the corresponding stop compresses and pushes the operating mechanism / operating structure of the buffer cylinder, causing the piston rod of the cylinder to retract with the valve. During the non-buffering phase or the early part of the non-buffering and buffering phases (not near the stop), the corresponding stop does not contact the operating mechanism / operating structure of the buffer cylinder.

[0066] As a preferred embodiment, the stop block matched with the two-position four-way throttle valve is trapezoidal, the main part of its outer edge (the edge facing the two-position four-way throttle valve) is a straight edge parallel to the movement direction of the door, one end of the outer edge (one side edge capable of interacting with the actuating member / actuating structure of the two-position four-way throttle valve) is a bevel edge (straight bevel edge or curved bevel edge), the two-position four-way throttle valve is fixed in position (for example, fixedly mounted on the frame of the door), with its axial direction (the axial direction of the plunger) perpendicular to the movement direction of the door, such that the movable area of the stop block includes the area where the front end of the actuating rod / actuating structure of the two-position four-way throttle valve is located (the area where it is located in the free state). When the stop block is not in front of the two-position four-way throttle valve in the axial direction, the plunger of the two-position four-way throttle valve is not blocked or squeezed by the outside (the stop block), and the plunger extends outward under the action of the plunger spring to the position in the non-throttling state. When the main part of the outer edge of the corresponding stop block moves to the front of the two-position four-way throttle valve in the axial direction, the actuating rod / actuating structure of the two-position four-way throttle valve is squeezed by the main part of the outer edge of the stop block, and the plunger retracts to the position in the throttling state. When the bevel edge at one end of the outer edge of the stop block moves in front of the two-position four-way throttle valve in the axial direction, the degree of squeezing of the actuating rod / actuating structure of the two-position four-way throttle valve by the bevel edge of the outer edge of the stop block gradually increases or decreases, realizing the transition from the non-throttling state to the throttling state or from the throttling state to the non-throttling state.

[0067] Since the two-position four-way throttle valve disclosed in the present invention is used for switching between adjacent stages, the pressure difference on both sides of the piston during the switching process is continuously and steplessly changed, so the change in the output speed of the piston rod is also continuously and steplessly changed, thereby ensuring smooth speed change at the start and end of the stroke, and avoiding the negative effects and adverse impacts caused by sharp speed changes under stepless regulation.

[0068] The present invention has the following features: The plunger valve unit of the two-position four-way throttle valve adopts a mutually matched plunger and valve sleeve, and relies on the axial movement of the plunger to open or block the non-throttling passage between the two inlet and outlet ports of the valve sleeve. In particular, since the front end portion of the plunger adopts a tapered structure, the blocking area for the non-throttling passage changes gradually, realizing continuous (stepless) change between complete blocking and complete opening. Moreover, the plunger stroke (moving distance) or the plunger movement duration between complete blocking and complete opening can be set or adjusted by changing the dimensions (for example, the axial length of the taper) and shapes (for example, changing the opening of the valve sleeve port / the valve sleeve port on the inner side wall of the valve sleeve from an opening formed by a circular hole / a circular hole to an opening formed by an elongated hole / an elongated hole along the axial direction of the plunger) of the relevant structures according to actual needs, so as to further set a suitable stepless change process and change speed; The control device uses a two-position four-way throttle valve to achieve synchronous pressure regulation of the rodless and rod chambers of the cylinder. This not only simplifies the overall structure, but also ensures that the pressure changes in the two chambers have an additive effect on the cylinder power and cylinder output, thereby effectively improving the regulation capability and helping to reduce the size of the two-position four-way throttle valve. The entire driving stroke (single stroke) of the cylinder is divided into three stages. At the beginning, the power is greater than the resistance, so the speed gradually increases. In the middle, the power and resistance are balanced to achieve a constant speed. At the end, the power is less than the resistance, so the speed gradually decreases. This not only helps to maintain high efficiency, but also the smooth speed change at both ends (beginning and end) helps to avoid the impact damage and safety hazards caused by rapid acceleration and deceleration.

[0069] By automatically cooperating with the stop block, the two-position four-way throttle valve, and the hydraulic cylinder buffer device, the working state of the two-position four-way throttle valve is automatically switched by the movement position of the door, thereby automatically controlling the output of the cylinder. During the stopping process, it automatically interacts with the hydraulic cylinder buffer device to achieve effective and reliable buffering. This not only makes it more convenient for users but also improves the reliability of control and helps to reduce safety risks.

[0070] Unless otherwise specified, the preferred and optional technical means disclosed in this invention can be arbitrarily combined to form several different specific embodiments when one preferred or optional technical means is a further limitation of another technical means.

Claims

1. Automatic door for large grinding machines, including: A door, a frame that moves linearly to the door, and one or more stops are fixedly connected to the door; A cylinder is a door drive device. Its piston rod moves in the same direction as the door. The outer end of the piston rod is connected to the door, thus enabling the door to move together. Its characteristic is that it further includes: A two-position four-way throttle valve is used to switch the throttling and non-throttling states of the connected pipeline. It is equipped with two plunger valve units, two air source side interfaces, and two cylinder side interfaces. The plunger valve unit includes a plunger and a valve sleeve that mates with the plunger. The rear end of the plunger is inserted into the valve sleeve, leaving a gap between it and the inner wall of the valve sleeve to form a throttling channel. The front end of the plunger is exposed outside the valve sleeve. The middle part of the valve sleeve has two valve sleeve through holes that penetrate the side wall of the valve sleeve. The circumferential surface of the plunger is provided with a plunger sealing ring for sealing with the inner wall of the valve sleeve. The plunger sealing ring is located in front of the valve sleeve through holes. The inner ends of the first air source side interface and the first cylinder side interface are respectively connected to the corresponding valve sleeve through holes on the first plunger valve unit. The inner ends of the second air source side interface and the second cylinder side interface are respectively connected to the corresponding valve sleeve through holes on the second plunger valve unit. The outer end of the first cylinder side interface is connected to the rodless chamber air inlet of the cylinder, and the outer end of the second cylinder side interface is connected to the rod chamber air inlet of the cylinder. The three-position five-way solenoid valve has three air source side interfaces and two cylinder side interfaces, which are used to switch the connection mode between the two cylinder side interfaces and the three air source side interfaces. The first cylinder side interface is connected to the first air source side interface of the two-position four-way throttle valve, the second cylinder side interface is connected to the second air source side interface of the two-position four-way throttle valve, the middle air source side interface is connected to the air supply pipe of the air source device, and the air source side interfaces on both sides are connected to the atmosphere. The hydraulic cylinder damper is equipped with a damping cylinder and damping oil pipes connected to the rod chamber and rodless chamber of the damping cylinder at both ends. The piston rod moves in the same direction as the door, and is used to dampen the door in the near-end area in the corresponding direction. The outer end of the piston rod of the damping cylinder is equipped with an operating element / operating structure that can interact with the corresponding stop block connected to the door. When the door moves to the corresponding set position, the stop block contacts the corresponding operating element / operating structure of the hydraulic cylinder damper, pushing the piston rod of the hydraulic cylinder to squeeze / move inward, thereby achieving damping by relying on the resistance of the hydraulic cylinder. The damping cylinder is equipped with a hydraulic cylinder spring for pushing its piston rod outward.

2. The automatic door for a large grinding machine as described in claim 1, characterized in that, A first one-way throttle valve is provided on the connecting pipe between the outer end of the first cylinder side interface of the two-position four-way throttle valve and the rodless chamber of the cylinder. A second one-way throttle valve is provided on the connecting pipe between the outer end of the second cylinder side interface of the two-position four-way throttle valve and the rod chamber of the cylinder. The throttling direction of the first one-way throttle valve and the second one-way throttle valve is the flow direction from the two-position four-way throttle valve to the cylinder.

3. The automatic door for a large grinding machine as described in claim 1, characterized in that, The two-position four-way throttle valve is equipped with a throttle valve body. The throttle valve body has valve sleeve mounting holes for fixing and installing plunger valve units. There are two valve body holes. The valve sleeves of the two plunger valve units are respectively fixedly installed in their respective valve sleeve mounting holes. The throttle valve body is equipped with connecting channels that communicate with the valve sleeve through holes on each valve sleeve. The outer end of the connecting channel is equipped with a pneumatic connector, which is used as an interface for connecting the corresponding connecting channel / valve sleeve through hole to the external pipeline.

4. The automatic door for a large grinding machine as described in claim 1, characterized in that, The valve sleeve of the plunger unit is equipped with a plunger spring that pushes the plunger forward. The plunger spring is located on the rear side of the plunger, and the front end of the plunger spring abuts against the rear end face of the plunger.

5. The automatic door for a large grinding machine as described in claim 4, characterized in that, The plunger of the two-position four-way throttle valve is equipped with an operating element / operating structure that can interact with the corresponding stop of the door. When the door moves to the corresponding set position, the operating element / operating structure on the two-position four-way throttle valve contacts the corresponding stop, and the plunger moves inward under the push of the stop, thereby realizing the state switching of the two-position four-way throttle valve.

6. The automatic door for a large grinding machine as described in claim 1, characterized in that, The cylinder is controlled as follows: the pneumatic stroke / cylinder drive stroke is divided into three stages: the beginning, the middle, and the end. At the beginning, the cylinder is operated at full pressure, or at the beginning stage, the cylinder is operated at reduced pressure, and at the end stage, the cylinder is operated at full pressure, so that the cylinder output speed continuously increases until the equilibrium speed of the middle stage is reached. In the middle stage, the cylinder is operated at full pressure, and the cylinder output speed remains constant. At the end, the cylinder operation mode is changed from full pressure operation to reduced pressure operation, and the cylinder output speed continuously decreases.

7. The automatic door for a large grinding machine as described in claim 6, characterized in that, Based on the method of controlling the cylinder, a two-position four-way throttle valve and corresponding stops are set up, and the cylinder operating pressure is automatically switched by the movement of the stops.

8. The automatic door for a large grinding machine as described in claim 7, characterized in that, The automatic switching of cylinder operating pressure via the movement of the stop block is as follows: When the cylinder is under full pressure control, the corresponding stop block does not compress / push the operating element / operating structure of the two-position four-way throttle valve, thus keeping the two-position four-way throttle valve in a non-throttle state; when the cylinder is under depressurization control, the corresponding stop block compresses / pushes the operating element / operating structure of the two-position four-way throttle valve, thus keeping the two-position four-way throttle valve in a throttle state; during the process of switching from full pressure control to depressurization control or from depressurization control to full pressure control, the corresponding stop block gradually compresses / pushes the operating element / operating structure of the two-position four-way throttle valve or gradually disengages from the operating element / operating structure of the two-position four-way throttle valve, realizing the stepless switching of the two-position four-way throttle valve from a non-throttle state to a throttle state or from a throttle state to a non-throttle state.

9. The automatic door for a large grinding machine as described in claim 1, characterized in that, The stopper matched with the two-position four-way throttle valve is trapezoidal, the main part of its outer edge is a straight edge parallel to the movement direction of the door, and one end of the outer edge is a bevel edge. The two-position four-way throttle valve is fixed in position, with its axial direction perpendicular to the movement direction of the door. When the stopper is not in front of the two-position four-way throttle valve in the axial direction, the plunger of the two-position four-way throttle valve is not blocked or squeezed by the outside, and the plunger extends outward to the position under the non-throttling state under the action of the plunger spring. When the main part of the outer edge of the corresponding stopper moves to the front of the two-position four-way throttle valve in the axial direction, the operating rod / operating structure of the two-position four-way throttle valve is squeezed by the main part of the outer edge of the stopper, and the plunger retracts to the position under the throttling state. When the bevel edge at one end of the outer edge of the stopper moves in front of the two-position four-way throttle valve in the axial direction, the squeezing degree of the operating rod / operating structure of the two-position four-way throttle valve by the bevel edge of the outer edge of the stopper gradually increases or gradually decreases, so as to realize the switching from the non-throttling state to the throttling state or from the throttling state to the non-throttling state.

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