A shoe pressure loading hydraulic cylinder

Abstract

The present invention provides a shoe pressure loading hydraulic cylinder, comprising a piston fixed to an upper roller core and a cylinder barrel; the cylinder barrel comprises a cylinder body and a cylinder bottom cover fixed to a lower shoe plate; a through hole is arranged on the cylinder bottom cover as an oil inlet; the cylinder body comprises an integrally arranged side wall and a bottom plate; the piston is slidably arranged up and down on the inner surface of the cylinder body side wall; a middle hole is arranged at the center of the bottom plate, the lower end of the cylinder bottom cover is arranged in the middle hole, the upper end of the cylinder bottom cover is pressed above the bottom plate of the cylinder body and is slidably connected to the bottom plate of the cylinder body; the bottom of the cylinder body is slidably connected to the shoe plate; an exhaust structure is arranged on the piston. The present invention realizes the stability of the hydraulic cylinder loading force by exhausting the exhaust part. The shoe plate and the back roller below can be better fitted by floating between the cylinder body and the shoe plate. Thereby, a stable pressure zone width and line pressure are ensured.

Description

Technical Field

[0001] The invention belongs to the field of shoe roller and shoe plate loading in papermaking, and in particular relates to a shoe pressure loading hydraulic cylinder. Background Art

[0002] The shoe press is a key component in papermaking machinery and an important device for pressing wet paper sheets in modern high-speed papermaking machines. The concave design on the shoe press can increase the width of the pressing zone, allowing the wet paper sheets to be dehydrated longer in the pressing zone, thereby improving the pressing efficiency. At the same time, the line pressure between the shoe press and the backing roller also needs to be precisely controlled to ensure uniform pressure distribution during the pressing process and avoid problems such as damage or indentation in the paper industry.

[0003] A loading hydraulic cylinder is arranged between the existing boot core and the boot plate. The upper boot core and the piston are fixedly connected, and the lower boot plate and the cylinder barrel are fixedly connected. The boot plate is subjected to great force and may deflect. The position of the hydraulic cylinder is fixed, and the loading force on the boot plate will be unstable. Patent CN209781339U discloses a one-way loading hydraulic cylinder for a boot roller, comprising an upper cover, a piston and a cylinder barrel. With this structure, when the boot plate is deflected and deformed and is not parallel to the bottom plate of the cylinder barrel, the high-pressure oil seal of the hydraulic cylinder can work normally, thereby ensuring the stability of the loading force of the hydraulic cylinder on the boot plate. However, in the actual working process, the fit between the boot plate and the upper and lower rollers may not be comprehensive, shortening the pressing area and affecting the pressing effect.

[0004] In addition, the loading hydraulic cylinder of the shoe roller in the shoe press needs to be loaded continuously for hundreds of hours when working, and the loading force must be constant without fluctuation. Due to continuous loading during operation, the hydraulic oil in the hydraulic cylinder and hydraulic pipeline is in a relatively static state and rarely flows. Due to the structural problems of the hydraulic pipeline and the presence of air in the hydraulic oil, it is easy for a certain amount of air to accumulate in the loading hydraulic cylinder. Since air is compressible, it often causes oil pressure fluctuations during operation, causing loading force fluctuations. Summary of the invention

[0005] The invention provides a shoe pressure loading hydraulic cylinder.

[0006] The objective of the present invention is achieved in the following manner: a shoe pressure loading hydraulic cylinder, comprising a piston fixed to an upper roller core, and a cylinder barrel; the cylinder barrel comprises a cylinder body, and a cylinder bottom cover fixed to a lower shoe plate; a through hole is arranged on the cylinder bottom cover as an oil inlet; the cylinder body comprises an integrally arranged side wall and a bottom plate; the piston is slidably arranged up and down on the inner surface of the cylinder body side wall; an intermediate hole is arranged at the center of the bottom plate, the lower end of the cylinder bottom cover is arranged in the intermediate hole, the upper end of the cylinder bottom cover is pressed above the bottom plate of the cylinder body and is slidably connected to the bottom plate of the cylinder body; the bottom of the cylinder body is slidably connected to the shoe plate; an exhaust structure is arranged on the piston.

[0007] The diameter of the upper end of the cylinder bottom cover is greater than the diameter of the lower end; the lower surface of the upper end of the cylinder bottom cover is clearance-matched with the upper surface of the bottom plate of the cylinder body.

[0008] The spacing between the lower surface of the upper end of the cylinder bottom cover and the upper surface of the bottom plate of the cylinder body is no more than 0.5 mm.

[0009] A sealing structure is arranged between the lower surface of the cylinder body and the shoe plate; a sealing structure is arranged between the outer surface of the piston and the inner surface of the cylinder body side wall; and a sealing structure is arranged on the contact surface between the piston and the roller core.

[0010] The exhaust structure includes an exhaust component body, a through hole is arranged in the exhaust component body, at least one section of the through hole is a small hole with a diameter not greater than 0.3 mm; the size of the small hole is smaller than the size of other positions of the through hole; an exhaust channel with one end connected to the outside is arranged on the piston; the exhaust component body is detachably arranged on the piston; one end of the through hole of the exhaust component body is connected to the highest position of the cavity, and the other end is connected to the exhaust channel.

[0011] A mounting end is arranged at any end of the through hole on the exhaust component body; the piston is in the shape of an inverted cylinder, and a center hole communicating with the inner cavity of the cylinder of the piston is arranged at the center position of the top of the piston; the center hole is a stepped hole which is larger at the top and smaller at the bottom, and a mounting hole is arranged on the bottom surface of the large hole of the center hole; the mounting end of the exhaust component body is arranged in the mounting hole, and the other end of the exhaust component body is close to the highest position in the large hole of the center hole; the exhaust channel is located below the mounting hole and intersects with the mounting hole.

[0012] The mounting end is cylindrical, and the outer surface of the mounting end is an optical axis or is provided with an external thread; the small hole is located in the middle section of the through hole, the upper section of the through hole is a conical hole, and the small end of the conical hole is connected to the small hole; the lower section of the through hole is a cylindrical hole, and one end of the cylindrical hole is connected to the small hole through a conical transition hole; the cylindrical hole is located at the mounting end, and the conical hole is far away from the mounting end; a straight groove is provided on the end of the exhaust component body away from the mounting end; the diameter of the small hole is between 0.1 mm and 0.3 mm; the exhaust component body is made of corrosion-resistant and wear-resistant material.

[0013] Compared with the prior art, the present invention achieves the stability of the hydraulic cylinder loading force through exhausting the exhaust member, and achieves better fit between the shoe plate and the backing roller below through the floating between the cylinder body and the shoe plate, thereby ensuring a stable nip width and line pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the loading hydraulic cylinder structure.

[0015] Figure 2It is a schematic diagram of a row of hydraulic cylinders between the roller core and the shoe plate.

[0016] Figure 3 It is a schematic diagram of the exhaust component body.

[0017] Figure 4 It is a schematic diagram of the installation of the exhaust component body on the piston.

[0018] Among them, 1 is the roller core, 2 is the shoe plate, 3 is the piston, 30 is the center hole, 4 is the cylinder body, 40 is the middle hole, 5 is the cylinder bottom cover, 50 is the oil inlet, 6 is the exhaust part body, 60 is the small hole, 61 is the conical hole, 62 is the cylindrical hole, 63 is the straight groove, 64 is the mounting end, 7 is the exhaust channel, 8 is the grid ring, and 9 is the oil seal. DETAILED DESCRIPTION

[0019] In the present invention, unless otherwise clearly specified and limited, the technical terms used in this application shall be the common meanings understood by the technicians of the present invention. The terms "connected", "connected", "fixed", "set", etc. should be understood in a broad sense, and may be fixedly connected, detachably connected, or integrated; may be directly connected, or indirectly connected through an intermediate medium; may be mechanically connected or electrically connected. Unless otherwise clearly specified and limited, the first feature "on" or "below" the second feature may be that the first and second features are in direct contact, or indirectly in contact through an intermediate medium. Moreover, the first feature "above" or "above" or "above" the second feature may be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below" or "below" or "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. Relational terms such as first, second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms used in the description, such as "center", "lateral", "longitudinal", "length", "width", "thickness", "height", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "clockwise", "counterclockwise", etc., to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation.

[0020] The following will provide a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings and specific embodiments. Figure 1-4As shown, the present invention provides a shoe pressure loading hydraulic cylinder. It includes a piston 3 fixed to the upper roller core 1 and a cylinder barrel; the cylinder barrel includes a cylinder body 4 and a cylinder bottom cover 5 fixed to the lower shoe plate 2; a through hole is arranged on the cylinder bottom cover as an oil inlet. The cylinder body 4 includes a side wall and a bottom plate arranged integrally; the piston 3 is arranged to slide up and down on the inner surface of the side wall of the cylinder body 4; a middle hole 40 is arranged at the center of the bottom plate, and the lower end of the cylinder bottom cover 5 is arranged in the middle hole 40, and the upper end of the cylinder bottom cover 5 is pressed above the bottom plate of the cylinder body 4 and is slidably connected to the bottom plate of the cylinder body 4; the bottom of the cylinder body 4 is slidably connected to the shoe plate 2. An exhaust structure is also arranged on the piston 3. In the present invention, the shoe plate 2 together with the cylinder bottom cover 5 riding thereon can slide horizontally with the cylinder body 4, so as to achieve fine adjustment and self-adaptation in the horizontal direction. When a whole row of loading hydraulic cylinders are installed at the same time, the position of the cylinder body 4 can be fine-tuned to facilitate the falling of the cylinder body 4. When the loading hydraulic cylinder device is working: when the shoe pressure shoe plate 2 is subjected to the reaction force given by the back roller and other components, the floating loading hydraulic cylinder device can absorb part of the impact force. And because the cylinder body 4 can float on the bottom surface of the shoe plate 2, the shoe pressure shoe plate 2 can be fine-tuned relative to the back roller, the shoe plate 2 and the back roller below can fit better, and the pressing area is wider, thereby maintaining a stable pressing area width and line pressure. The present invention has a simple structure and is easy to install and maintain. The exhaust structure can ensure the stability of the hydraulic cylinder loading force. Further ensure the line pressure.

[0021] Furthermore, the diameter of the upper end of the cylinder bottom cover 5 is larger than the diameter of the lower end; the lower surface of the upper end of the cylinder bottom cover 5 is clearance-matched with the upper surface of the bottom plate of the cylinder body 4. The cylinder body 4 can float on the shoe plate 2. Under the clearance fit, the friction between the shoe plate 2 and the cylinder body 4, and between the cylinder bottom cover 5 and the bottom plate of the cylinder body 4 is smaller, and the position can be better adjusted according to the external force.

[0022] The gap between the lower surface of the upper end of the cylinder bottom cover 5 and the upper surface of the bottom plate of the cylinder body 4 is not greater than 0.5 mm, preferably 0.2 mm, to avoid excessive gaps that may cause oil leakage.

[0023] Among them, a sealing structure is arranged between the lower surface of the cylinder body 4 and the boot plate 2; a through hole is arranged on the cylinder bottom cover 5 as an oil inlet 50. It can be a dynamic seal or an oil seal 9. For example, a common sealing ring. A sliding connection or a floating structure needs to be provided with a sealing structure to prevent oil leakage. The sealing structure here is preferably an oil seal 9, and the method for setting the oil seal 9 belongs to the prior art and will not be described in detail. The inlet and outlet oil ports are all present in the existing loading hydraulic cylinders and will not be described in detail.

[0024] A sealing structure is provided between the outer surface of the piston 3 and the inner surface of the side wall of the cylinder body 4; a sealing structure is provided on the contact surface between the piston 3 and the roller core 1. A Gly ring 8 can be provided at the contact position between the piston 3 and the side wall of the cylinder body 4 to prevent the oil in the cylinder body 4 from leaking out. A sealing ring is provided on the contact surface between the piston 3 and the roller core 1 to prevent oil leakage when the hydraulic cylinder is working. Other common structures for sealing hydraulic oil may also be used, which will not be described in detail here. In addition, a countersunk hole is processed on the bottom surface of the piston 3, and the piston 3 is fixed to the roller core 1 by bolts. A countersunk hole is also provided on the cylinder bottom cover 5, and the cylinder bottom cover 5 is fixed to the shoe plate 2 by bolts. Furthermore, a row of loading hydraulic cylinders of the above structure are arranged side by side between the roller core 1 and the shoe plate 2.

[0025] In addition, the exhaust structure includes an exhaust member body 6, a through hole is arranged in the exhaust member body 6, at least one section of the through hole is a small hole 60 with a diameter not greater than 0.3 mm; the size of the small hole 60 is smaller than the size of other positions of the through hole; the piston 3 is provided with an exhaust channel 7 with one end connected to the outside of the hydraulic cylinder cavity; the exhaust member body 6 is detachably arranged on the piston 3; one end of the through hole of the exhaust member body 6 is connected to the highest position of the cavity, and the other end is connected to the exhaust channel 7. The small hole 60 is arranged in the through hole, which is currently used for throttling and distributing flow. At this time, the size of the small hole 60 is greater than 0.5 mm. Generally, it can be set between 0.5 mm and 2 mm. In the present invention, a small hole 60 of less than 0.3 mm is used for exhaust flow control for the first time. According to actual needs, the smaller the diameter of the small hole 60, the better. However, a hole that is too small is not easy to process, and the processing difficulty and cost will increase a lot. When the viscosity of the hydraulic oil passing through the small hole 60 is large, a large value is taken, and when the viscosity is small, a small value is taken. Here, the highest position of the cavity is a range, and the distance from the highest position can be a certain distance, such as a distance of several millimeters.

[0026] The exhaust member body 6 is provided with a mounting end 64 at any end of the through hole; the piston 3 is in the shape of an inverted cylinder, and a center hole 30 communicating with the inner cavity of the cylinder of the piston 3 is provided at the top center of the piston 3; the center hole 30 is a stepped hole that is larger at the top and smaller at the bottom, and a mounting hole is provided at the bottom surface of the large hole of the center hole 30; the mounting end 64 of the exhaust member body 6 is provided in the mounting hole, and the other end of the exhaust member body 6 is close to the highest position in the large hole of the center hole 30; the exhaust channel 7 is located below the mounting hole and intersects with the mounting hole. The exhaust channel 7 is preferably a blind hole provided in a transverse direction. It can also be another exhaust structure as long as exhaust can be achieved.

[0027] The mounting end 64 is cylindrical, and the outer surface of the mounting end 64 is an optical axis or an external thread; the small hole 60 is located in the middle section of the through hole, the upper section of the through hole is a conical hole 61, and the small end of the conical hole 61 is connected to the small hole 60; the lower section of the through hole is a cylindrical hole 62, and one end of the cylindrical hole 62 is connected to the small hole 60 through a conical transition hole; the cylindrical hole 62 is located at the mounting end 64, and the conical hole 61 is far away from the mounting end 64; a straight groove 63 is provided on the end of the exhaust body 6 away from the mounting end 64; the diameter of the small hole 60 is between 0.1 mm and 0.3 mm; the exhaust body 6 is made of corrosion-resistant and wear-resistant material. The width of the straight groove 63 can be 1 mm. The straight groove 63 can be conveniently used to use tools such as screwdrivers to install the exhaust body 6 of the present invention on the required product or remove it from the product. The exhaust body 6 can be made of copper alloy or stainless steel. The mounting end 64 is connected with other products, such as a hydraulic cylinder, by threaded connection. Of course, the mounting end 64 can also be an optical axis, which is matched with a hole on other products by a matching method. Or the mounting end 64 is set on other products by bolt connection, etc. The thread of the mounting end 64 can be an M4-M6 external thread.

[0028] The exhaust component of the boot pressure loading hydraulic cylinder in the present invention is installed on the hydraulic cylinder body. When in use, oil is filled into the hydraulic cylinder through a pipeline, and the air originally accumulated in the hydraulic cylinder will gather at the upper part of the hydraulic cylinder. As the hydraulic oil is filled, the air is discharged through the small hole 60 on the exhaust component. Without air in the hydraulic cylinder, the loading force will not fluctuate. During use, a small amount of liquid oil will be discharged through the small hole 60. Since the boot pressure loading hydraulic cylinder is installed in a closed space, and due to the needs of lubrication and cooling, a large amount of oil exists in the closed space, so the small hole 60 discharges a small amount of oil and will not cause oil leakage pollution problems. In addition, since the amount of oil discharged is very small and the diameter of the oil inlet pipe of the loading hydraulic cylinder is very large, a small amount of oil discharge will not cause the oil pressure of the loading hydraulic cylinder to decrease.

[0029] During specific implementation: a back roller is arranged below the shoe plate 2. A pressing zone is formed between the shoe plate 2 and the back roller. A row of loading hydraulic cylinders is arranged between the shoe plate 2 and the upper shoe core. When loading is required: hydraulic oil enters the cavity of the loading hydraulic cylinder through the oil inlet 50 to pressurize the loading hydraulic cylinder. The loading force of the hydraulic cylinder is stabilized by exhausting the exhaust part. The shoe plate 2 and the back roller below can be better fitted by floating between the cylinder body 4 and the shoe plate 2. Thus, a stable pressing zone width and line pressure are ensured.

[0030] The technical features of the above-mentioned embodiments can be combined arbitrarily, and as long as there is no contradiction in the combination of these technical features, they should be considered as the scope of this specification. Without departing from the overall concept of the present invention, the technical solution of the present invention and the equivalent replacement or change, as well as the changes and improvements made, should also be regarded as the protection scope of the present invention.

Claims

1. A shoe pressure loading hydraulic cylinder, comprising a piston fixed to an upper roller core and a cylinder barrel; characterized in that: The cylinder barrel includes a cylinder body and a cylinder bottom cover fixed to a boot plate below; a through hole is arranged on the cylinder bottom cover as an oil inlet; the cylinder body includes an integrally arranged side wall and a bottom plate; the piston is slidably arranged up and down on the inner surface of the cylinder body side wall; an intermediate hole is arranged at the center of the bottom plate, the lower end of the cylinder bottom cover is arranged in the intermediate hole, the upper end of the cylinder bottom cover is pressed above the bottom plate of the cylinder body and is slidably connected to the bottom plate of the cylinder body; the bottom of the cylinder body is slidably connected to the boot plate; an exhaust structure is arranged on the piston.

2. A shoe pressure loading hydraulic cylinder according to claim 1, characterized in that: The diameter of the upper end of the cylinder bottom cover is greater than the diameter of the lower end; the lower surface of the upper end of the cylinder bottom cover is clearance-matched with the upper surface of the bottom plate of the cylinder body.

3. A shoe pressure loading hydraulic cylinder according to claim 2, characterized in that: The spacing between the lower surface of the upper end of the cylinder bottom cover and the upper surface of the bottom plate of the cylinder body is no more than 0.5 mm.

4. The floating loading hydraulic cylinder device according to claim 1, characterized in that: A sealing structure is arranged between the lower surface of the cylinder body and the shoe plate; a sealing structure is arranged between the outer surface of the piston and the inner surface of the cylinder body side wall; and a sealing structure is arranged on the contact surface between the piston and the roller core.

5. The shoe pressure loading hydraulic cylinder according to claim 1, characterized in that: The exhaust structure includes an exhaust component body, a through hole is arranged in the exhaust component body, at least one section of the through hole is a small hole with a diameter not greater than 0.3 mm; the size of the small hole is smaller than the size of other positions of the through hole; an exhaust channel with one end connected to the outside is arranged on the piston; the exhaust component body is detachably arranged on the piston; one end of the through hole of the exhaust component body is connected to the highest position of the cavity, and the other end is connected to the exhaust channel.

6. A shoe pressure loading hydraulic cylinder according to claim 5, characterized in that: A mounting end is arranged at any end of the through hole on the exhaust component body; the piston is in the shape of an inverted cylinder, and a center hole communicating with the inner cavity of the cylinder of the piston is arranged at the center position of the top of the piston; the center hole is a stepped hole which is larger at the top and smaller at the bottom, and a mounting hole is arranged on the bottom surface of the large hole of the center hole; the mounting end of the exhaust component body is arranged in the mounting hole, and the other end of the exhaust component body is close to the highest position in the large hole of the center hole; the exhaust channel is located below the mounting hole and intersects with the mounting hole.

7. A shoe pressure loading hydraulic cylinder according to claim 6, characterized in that: The mounting end is cylindrical, and the outer surface of the mounting end is an optical axis or is provided with an external thread; the small hole is located in the middle section of the through hole, the upper section of the through hole is a conical hole, and the small end of the conical hole is connected to the small hole; the lower section of the through hole is a cylindrical hole, and one end of the cylindrical hole is connected to the small hole through a conical transition hole; the cylindrical hole is located at the mounting end, and the conical hole is far away from the mounting end; a straight groove is provided on the end of the exhaust component body away from the mounting end; the diameter of the small hole is between 0.1 mm and 0.3 mm; the exhaust component body is made of corrosion-resistant and wear-resistant material.

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