A composite material hydraulic cylinder barrel and a preparation method thereof

Abstract

The application provides a composite hydraulic cylinder barrel and a preparation method thereof, and the barrel comprises the following steps: clamping a first core shaft mold to a winding device, winding glass fiber bundles or carbon fiber bundles on the first core shaft mold after the glass fiber bundles or the carbon fiber bundles are impregnated with a liquid resin, and forming a glass fiber tube or a carbon fiber tube by heating and curing; forming a cylinder lining tube by chipping, demolding and cutting the glass fiber tube or the carbon fiber tube, and performing air tightness detection on the cylinder lining tube; sequentially sleeving a bottom metal piece, the cylinder lining tube and a top metal piece on a second core shaft mold to form a lining tube assembly after the bottom metal piece and the top metal piece containing a sealing groove are prepared, and a sealing ring is arranged between the metal piece and the cylinder lining tube; winding the glass fiber bundles or the carbon fiber bundles on the lining tube assembly, forming a cylinder backing by heating and curing, taking out the second core shaft mold, and finally forming the hydraulic cylinder barrel. The application can effectively avoid oil leakage in a gap during hydraulic cylinder work, and thus the work failure of the hydraulic cylinder is avoided.

Description

Technical Field

[0001] This application relates to the field of hydraulic cylinder technology, specifically to a composite material hydraulic cylinder barrel and its preparation method. Background Technology

[0002] Hydraulic cylinders are common hydraulic components widely used in various mechanical equipment. Their main function is to convert hydraulic energy into mechanical energy, enabling the movement and control of mechanical equipment. The applications of hydraulic cylinders are very broad, including: 1. Industrial machinery: Hydraulic cylinders are widely used in various industrial machinery, such as metallurgical equipment, mining machinery, construction machinery, and lifting equipment. 2. Agricultural machinery: Hydraulic cylinders are also widely used in agricultural machinery, such as tractors, harvesters, and irrigation equipment. 3. Aerospace: Hydraulic cylinders are also widely used in the aerospace field, such as in aircraft landing gear and flight control systems. 4. Automotive industry: Hydraulic cylinders are also used in the automotive industry, such as in automotive braking systems and suspension systems. 5. Other fields: Hydraulic cylinders are also used in other fields, such as medical equipment and environmental protection equipment. In short, hydraulic cylinders are a very important hydraulic component with a wide range of applications, providing crucial support for the movement and control of various mechanical equipment.

[0003] Traditional hydraulic cylinders are mostly made of metal, which has drawbacks such as poor corrosion resistance, heavy weight, poor insulation and magnetism, easy wear, and susceptibility to cracking. While using a combination of metal and resin-based glass fiber (carbon fiber) composite materials for hydraulic cylinders—with the cylinder barrel made of resin-based glass fiber (carbon fiber) composite material and metal ends—offers significant weight reduction, the difference in thermal expansion coefficients between the resin-based glass fiber (carbon fiber) composite material and the metal parts means that gaps inevitably exist between them during the heat curing process. This can lead to oil leakage and product defects. Furthermore, during the heat curing process of the resin-based glass fiber (carbon fiber) composite cylinder barrel, the interlayer bonding becomes less stable with increasing wall thickness, making delamination more likely and resulting in oil leakage.

[0004] In view of this, this application proposes a composite material hydraulic cylinder barrel and its preparation method, which can effectively avoid oil leakage from gaps during operation of the hydraulic cylinder, thus preventing cylinder failure. Summary of the Invention

[0005] To address the problem of unavoidable gaps between metal parts and resin-based composite materials when they are bonded together by heating and curing in existing hydraulic cylinders, which leads to oil leakage and substandard hydraulic cylinder products, this application provides a composite material hydraulic cylinder barrel and its preparation method to solve the above-mentioned technical defects.

[0006] According to one aspect of the present invention, a method for preparing a composite material hydraulic cylinder barrel is provided, the method comprising the following steps:

[0007] S1. The first mandrel mold is clamped onto the winding equipment and a release agent is applied. After the glass fiber bundle or carbon fiber bundle is impregnated with liquid resin, it is wound around the first mandrel mold at an angle of 45-90 degrees and cured by heating to form a glass fiber tube or carbon fiber tube.

[0008] S2. After turning, demolding and cutting the glass fiber tube or carbon fiber tube, a cylinder liner is formed. Sealing devices are installed at both ends of the cylinder liner, and an air inlet is reserved at one end of the sealing device.

[0009] S3. Place the cylinder liner vertically into the water, add air pressure through the air inlet, and check if there are any bubbles coming out of the water from the cylinder liner. If no bubbles come out, remove the sealing devices at both ends of the cylinder liner and continue with step S4.

[0010] S4. After preparing the bottom metal part and the top metal part containing the sealing groove, the bottom metal part, the cylinder liner tube and the top metal part are sequentially fitted onto the second mandrel mold to form the liner tube assembly. Multiple sealing rings are provided between the metal part and the cylinder liner tube.

[0011] S5. After applying liquid resin to the outer surface of the inner liner assembly, wind glass fiber bundles or carbon fiber bundles around the inner liner assembly at an angle of 20-89 degrees and cure by heating to form a cylinder backing.

[0012] S6. On the demolding equipment, the second mandrel mold is extracted to finally form the hydraulic cylinder.

[0013] Through the above technical solution, this application can effectively avoid oil leakage in the cylinder caused by poor inner liner tube, and at the same time avoid waste of materials and production time, reduce production costs and improve production efficiency.

[0014] Preferably, in step S1, impregnating the glass fiber bundle or carbon fiber bundle with the liquid resin further includes the following sub-steps:

[0015] S11. Add the resin to the impregnation tank and heat the resin in the impregnation tank with a heating device to make the resin into liquid resin.

[0016] S12. The liquid resin is continuously heated by a heating device to maintain the temperature of the liquid resin at 40-65℃.

[0017] S13. After passing the glass fiber bundle or carbon fiber bundle through the impregnation tank, it is wound around the first mandrel mold at an angle of 45-90 degrees and cured by heating at a temperature of 130-170℃ to form a glass fiber tube or carbon fiber tube.

[0018] The above technical solutions enable the simple and rapid preparation of high-performance glass fiber tubes or carbon fiber tubes, facilitating subsequent operations.

[0019] Preferably, in step S4, preparing the bottom metal part and the top metal part containing the sealing groove includes the following sub-steps:

[0020] S411. Process and manufacture according to the dimensions designed in the drawings to obtain metal blanks;

[0021] S412. Degrease and sandblast roughen the outer surface of the metal blank;

[0022] S413. A sealing groove is provided on the metal blank to form a bottom metal part and a top metal part.

[0023] In the above technical solution, glass fiber or carbon fiber composite material is wound around the outer surface of the metal part. During the process of heating, curing and cooling to combine them into one, due to the difference in the coefficients of thermal expansion and contraction of the two materials, gaps that cannot be detected by the naked eye are generated between the two materials. Therefore, this application can prevent hydraulic oil or gas from seeping out from the gaps by setting a sealing ring.

[0024] Preferably, step S4 further includes preparing a second mandrel mold, specifically including the following sub-steps:

[0025] S421. Machining according to the dimensions designed in the drawings to obtain the mandrel blank;

[0026] S422. Grind the outer surface of the mandrel blank to reduce the surface roughness of the mandrel blank and form a second mandrel mold.

[0027] The above technical solutions can reduce the friction coefficient and surface roughness of the mold, making it easier to mold and preventing damage to the inner wall of the cylinder liner.

[0028] Preferably, in step S4, the bottom metal part, the cylinder liner tube, and the top metal part are sequentially fitted onto the second mandrel mold to form the liner tube assembly, including the following sub-steps:

[0029] S431. Install the corresponding sealing rings into the multiple sealing grooves of the bottom metal part respectively;

[0030] S432. Insert the stepped end of the second mandrel mold into the bottom metal part;

[0031] S433. Pass the pre-tightening screw through the bottom metal part, screw it into the screw hole at the bottom of the second mandrel mold and tighten it;

[0032] S434, The cylinder inner liner tube passes through the second mandrel mold and is connected to the bottom metal part through a sealing ring;

[0033] S435. After installing the corresponding sealing rings into the multiple sealing grooves of the top metal part, the top metal part is passed through the second mandrel mold and pressed into the cylinder liner tube to form the liner tube assembly.

[0034] Preferably, in step S435, pressing the top metal piece through the second mandrel mold into the cylinder liner further includes the following steps:

[0035] After the support and limiting component is screwed into the top metal part through the second mandrel mold, the connecting rod is fixed to the end face of the support and limiting component by the locking screw to form the inner liner tube assembly.

[0036] Preferably, one end of the bottom metal part is provided with a first step and a second step, the first step is provided with two sealing grooves, and the second step is provided with one sealing groove.

[0037] Preferably, the top metal part is provided with two sealing grooves.

[0038] Preferably, step S1 further includes preparing a first mandrel mold, specifically including: turning according to the design dimensions in the drawing to obtain a mandrel blank; grinding the outer surface of the mandrel blank to reduce the surface roughness of the mandrel blank, and forming the first mandrel mold.

[0039] By using the above technical solutions, the surface friction coefficient and surface roughness of the first mandrel mold are reduced, thereby improving the smoothness of the inner wall of the prepared inner liner tube.

[0040] Secondly, this application provides a composite material hydraulic cylinder barrel, which is prepared according to the preparation method of the composite material hydraulic cylinder barrel described in any one of the above claims.

[0041] Compared with the prior art, the beneficial results of the present invention are as follows:

[0042] (1) The cylinder barrel is made of resin-based glass fiber or carbon fiber composite material, which greatly reduces the weight of the cylinder and makes it easy to handle and carry.

[0043] (2) During the curing and bonding process of metal parts with resin-based glass fiber or carbon fiber composite materials, due to the difference in the coefficients of thermal expansion and contraction of the two materials, unavoidable gaps that are difficult to detect with the naked eye are generated. This invention can effectively prevent the hydraulic cylinder from leaking oil from the gaps during operation, which would cause the hydraulic cylinder to fail.

[0044] (3) The introduction of the cylinder liner tube in this invention not only effectively avoids the problem of unstable interlayer bonding of the cylinder body due to the large wall thickness, but also allows the cylinder body to be detected in advance through the air tightness test of the cylinder liner tube. This can effectively avoid oil leakage caused by poor liner tube, and also avoid waste of materials and production time, thereby reducing production costs and improving production efficiency. Attached Figure Description

[0045] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments, taken with reference to the accompanying drawings:

[0046] Figure 1 This is a flowchart of the method for preparing the cylinder barrel of a composite material hydraulic cylinder according to this application;

[0047] Figure 2a This is an overall structural diagram of the hydraulic cylinder barrel according to this application;

[0048] Figure 2b This is a structural schematic diagram of the first mandrel mold according to this application;

[0049] Figure 3a This is a cross-sectional view of the bottom metal part according to this application;

[0050] Figure 3b This is a structural schematic diagram of the bottom metal part according to this application;

[0051] Figure 4a This is a cross-sectional view of the top metal part according to this application;

[0052] Figure 4b This is a structural schematic diagram of the top metal component according to this application;

[0053] Figure 5 This is a split schematic diagram of the hydraulic cylinder barrel according to this application;

[0054] Figure 6 This is an assembly diagram of the hydraulic cylinder barrel according to this application.

[0055] Explanation of reference numerals in the attached drawings: First mandrel mold 11, screw hole 111 of the first mandrel mold, second mandrel mold 12, screw hole 121 at the bottom of the second mandrel mold, screw hole 122 at the top of the second mandrel mold, cylinder inner liner tube 2, bottom metal part 31, first step portion 311, sealing groove on the first step portion 313, first sealing ring 301, second sealing ring 302, second step portion 312, sealing groove on the second step portion 314, tapered portion 315, third sealing ring 303, top metal part 32, sealing groove on the top metal part 321, thread 322, fourth sealing ring 304, fifth sealing ring 305, preload screw 4, support and limiting part 5, locking screw 6, connecting rod 7, cylinder backing 8. Detailed Implementation

[0056] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0057] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0058] Figure 1 A flowchart illustrating the preparation method of the composite material hydraulic cylinder barrel of this application is shown, as follows: Figure 1 As shown, Figure 2a An overall structural diagram of the hydraulic cylinder barrel according to this application is shown. Figure 2b A schematic diagram of the structure of the first mandrel mold according to this application is shown, in conjunction with reference to the reference. Figure 1 , Figure 2a and Figure 2b The method for preparing the composite material hydraulic cylinder barrel provided in this application includes the following steps:

[0059] S1. The first mandrel mold 11 is clamped onto the winding equipment and a release agent is applied. After the glass fiber bundle or carbon fiber bundle is impregnated with liquid resin, it is wound around the first mandrel mold 11 at an angle of 45-90 degrees and cured by heating to form a glass fiber tube or carbon fiber tube.

[0060] Preferably, step S1 further includes the preparation of a first mandrel mold, specifically including:

[0061] (1) Machining according to the dimensions designed in the drawings to obtain the mandrel blank;

[0062] (2) Grinding is performed on the outer surface of the mandrel blank to reduce the friction coefficient and surface roughness of the first mandrel mold, thereby forming the first mandrel mold. The smoothness of the inner wall of the cylinder liner tube prepared subsequently can be improved through the above operation.

[0063] Preferably, in step S1, impregnating the glass fiber bundle or carbon fiber bundle with the liquid resin further includes the following sub-steps:

[0064] S11. Add the resin to the impregnation tank and heat the resin in the impregnation tank with a heating device to turn the resin into liquid resin.

[0065] S12. The liquid resin is continuously heated by a heating device to maintain the temperature of the liquid resin at 40-65℃.

[0066] S13. After passing the glass fiber bundle or carbon fiber bundle through the impregnation tank, it is wound around the first mandrel mold 11 at an angle of 45-90 degrees and cured by heating at a temperature of 130-170℃ to form a glass fiber tube or carbon fiber tube.

[0067] S2. After turning, demolding and cutting the glass fiber tube or carbon fiber tube, a cylinder inner liner tube 2 is formed. Sealing devices are installed at both ends of the cylinder inner liner tube 2, and an air inlet is reserved at one end of the sealing device.

[0068] S3. Place the cylinder liner 2 vertically into the water, add air pressure through the air inlet, and check whether there are bubbles coming out of the water from the cylinder liner 2. If no bubbles come out, remove the sealing devices at both ends of the cylinder liner 2 and continue with step S4.

[0069] S4. After preparing the bottom metal part 31 and the top metal part 32 containing sealing grooves, the bottom metal part 31, the cylinder inner liner tube 2 and the top metal part 32 are sequentially fitted onto the second mandrel mold 12 to form an inner liner tube assembly. Multiple sealing rings are provided between the metal parts (including the bottom metal part 31 and the top metal part 32) and the cylinder inner liner tube 2.

[0070] The preparation of the bottom metal part 31 and the top metal part 32 containing the sealing groove includes the following sub-steps:

[0071] S411. Process and manufacture according to the dimensions designed in the drawings to obtain metal blanks;

[0072] S412. Degrease and sandblast roughen the outer surface of the metal blank;

[0073] S413. A sealing groove is provided on the metal blank to form a bottom metal part 31 and a top metal part.

[0074] The purpose of the sealing grooves designed for metal parts is to install sealing rings. When glass fiber or carbon fiber composite materials are wrapped around the outer surface of the metal parts and bonded together by curing and cooling, gaps that are not visible to the naked eye are created between the two materials due to the difference in their coefficients of thermal expansion and contraction. By using sealing rings, hydraulic oil or gas is prevented from seeping out from the gaps.

[0075] Figure 3a A cross-sectional view of the bottom metal part according to this application is shown. Figure 3b A schematic diagram of the structure of the bottom metal part according to this application is shown, in conjunction with reference to the reference. Figure 2a , Figure 3a and Figure 3b In a specific embodiment, one end of the bottom metal part 31 is provided with a first step portion 311 and a second step portion 312, wherein the first step portion 311 is provided with two sealing grooves 313 and the second step portion 312 is provided with one sealing groove 314.

[0076] In a specific embodiment, the tapered portion 315 provided on the bottom metal part 31 is subjected to sandblasting roughening treatment.

[0077] Figure 4a A cross-sectional view of the top metal part according to this application is shown. Figure 4b A structural schematic diagram of the top metal part according to this application is shown, in conjunction with reference to the reference. Figure 2a , Figure 4a and Figure 4b In a specific embodiment, the top metal part 32 is provided with two sealing grooves 321. The top metal part 32 is provided with threaded teeth 322, and the threaded teeth 322 are roughened by sandblasting.

[0078] Preferably, step S4 further includes the preparation of the second mandrel mold 12, specifically including the following sub-steps:

[0079] S421. Machining according to the dimensions designed in the drawings to obtain the mandrel blank;

[0080] S422. Grind the outer surface of the mandrel blank to reduce the surface roughness of the mandrel blank and form the second mandrel mold 12.

[0081] Figure 5 This diagram shows a disassembled schematic of the hydraulic cylinder barrel of this application. Figure 6 An assembly schematic diagram of the hydraulic cylinder barrel according to this application is shown, in conjunction with reference to the reference. Figure 3a , Figure 3b , Figure 4a , Figure 4b , Figure 5 and Figure 6In step S4, the bottom metal part 31, the cylinder inner liner tube 2, and the top metal part 32 are sequentially fitted onto the second mandrel mold 12 to form the inner liner tube assembly, including the following sub-steps:

[0082] S431. Install corresponding sealing rings in the multiple sealing grooves of the bottom metal part 31 respectively; specifically, place the first sealing ring 301 and the second sealing ring 302 in the two sealing grooves 313 on the first step portion 311 of the bottom metal part 31, and place the third sealing ring 303 in the sealing groove 314 of the second step 312 of the bottom metal part 31.

[0083] S432, Insert the stepped end of the second mandrel mold 12 into the bottom metal part 31;

[0084] S433. Pass the pre-tightening screw 4 through the bottom metal part 31, screw it into the screw hole 121 at the bottom of the second mandrel mold 12 and tighten it.

[0085] S434, the cylinder inner liner tube 2 passes through the second mandrel mold 12 and is connected to the bottom metal part 31 through the sealing rings (here referring to: the first sealing ring 301, the second sealing ring 302 and the third sealing ring 303);

[0086] S435. After installing the corresponding sealing rings into the multiple sealing grooves of the top metal part 32, the top metal part 32 is passed through the second mandrel mold 12 and pressed into the cylinder inner liner tube 2; specifically, the fourth sealing ring 304 and the fifth sealing ring 305 are placed in the two sealing grooves 321 of the top metal part 32.

[0087] S346. After the support limiting member 5 is screwed into the top metal part 32 through the second mandrel mold 12, the connecting rod 7 is fixed to the end face of the support limiting member 5 by the locking screw 6 to form the inner liner tube assembly.

[0088] Preferably, the support limiting member 5 is a metal support limiting member.

[0089] Preferably, the first mandrel mold 11 is provided with screw holes 111. Figure 2b (As shown in the image), it is used to install the connecting rod 7.

[0090] Continue to refer to Figure 1 The method for preparing the composite material hydraulic cylinder barrel provided in this application further includes:

[0091] S5. Clamp the inner liner assembly onto the winding equipment, and after manually applying a layer of liquid resin to the outer surface of the inner liner assembly, wind glass fiber bundles or carbon fiber bundles around the inner liner assembly at an angle of 20-89 degrees Celsius, and cure by heating at a temperature maintained at 130-170°C to form the cylinder backing 8. Figure 2a (as shown in the image);

[0092] S6. On the demolding equipment, the second mandrel mold 12 is pulled out to finally form the hydraulic cylinder.

[0093] Secondly, this application also provides a composite material hydraulic cylinder barrel, prepared according to the preparation method of the composite material hydraulic cylinder barrel described in any one of the above claims. For example... Figure 6 As shown, the pre-tightening screw 4 passes through the bottom metal part 31 and is screwed into the bottom of the second mandrel mold 12, so that one end of the cylinder liner tube 2 is connected to the bottom metal part 31. Furthermore, a first sealing ring 301, a second sealing ring 302, and a third sealing ring 303 are provided at the connection between the cylinder liner tube 2 and the bottom metal part 31.

[0094] The top metal part 32 passes through the second mandrel mold 12 and is pressed into the cylinder inner liner tube 2. A fourth sealing ring 304 and a fifth sealing ring 305 are provided at the connection between the top metal part 32 and the second mandrel mold 12.

[0095] Furthermore, after the support limiting member 5 passes through the second mandrel mold 12 and is screwed into the top metal part 32, the connecting rod 7 is fixed to the end face of the support limiting member 5 by the locking screw 6 to form the inner liner tube assembly.

[0096] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for preparing a composite material hydraulic cylinder barrel, characterized in that, Includes the following steps: S1. The first mandrel mold is clamped onto the winding equipment and a release agent is applied. After the glass fiber bundle or carbon fiber bundle is impregnated with liquid resin, it is wound around the first mandrel mold at an angle of 45-90 degrees and cured by heating to form a glass fiber tube or carbon fiber tube. S2. After turning, demolding and cutting the glass fiber tube or carbon fiber tube, a cylinder liner tube is formed. Sealing devices are installed at both ends of the cylinder liner tube, and an air inlet is reserved at one end of the sealing device. S3. Vertically place the cylinder liner tube into the water, add air pressure through the air inlet, and check whether there are bubbles coming out of the water from the cylinder liner tube. If no bubbles come out, remove the sealing devices at both ends of the cylinder liner tube and continue with step S4. S4. After preparing the bottom metal part and the top metal part containing the sealing groove, the bottom metal part, the cylinder liner tube, and the top metal part are sequentially fitted onto the second mandrel mold to form the liner tube assembly. Multiple sealing rings are provided between the metal parts and the cylinder liner tube. This includes the following sub-steps: S431. Install corresponding sealing rings into the multiple sealing grooves of the bottom metal part respectively; S432. Insert the stepped end of the second mandrel mold into the bottom metal part; S433. Pass the pre-tightening screw through the bottom metal part, screw it into the screw hole at the bottom of the second mandrel mold and tighten it; S434. The cylinder liner tube passes through the second mandrel mold and is connected to the bottom metal part through the sealing ring; S435. After installing corresponding sealing rings into the multiple sealing grooves of the top metal part, the top metal part is passed through the second mandrel mold and pressed into the cylinder liner tube to form the liner tube assembly, including the following steps: After the support limiting member is screwed into the top metal part through the second mandrel mold, the connecting rod is fixed to the end face of the support limiting member by the locking screw to form the inner liner tube assembly. S5. After applying liquid resin to the outer surface of the inner liner assembly, wind glass fiber bundles or carbon fiber bundles around the inner liner assembly at an angle of 20-89 degrees and cure by heating to form a cylinder backing. S6. On the demolding equipment, the second mandrel mold is extracted to finally form the hydraulic cylinder.

2. The method for preparing the composite material hydraulic cylinder barrel according to claim 1, characterized in that, In step S1, impregnating the glass fiber bundle or carbon fiber bundle with the liquid resin further includes the following sub-steps: S11. Add resin to the impregnation tank and heat the resin in the impregnation tank using a heating device to turn the resin into a liquid resin. S12. The liquid resin is continuously heated by a heating device to maintain the temperature of the liquid resin at 40-65°C. S13. After passing the glass fiber bundle or carbon fiber bundle through the impregnation tank, it is wound around the first mandrel mold at an angle of 45-90 degrees, and cured by heating at a temperature of 130-170°C to form the glass fiber tube or carbon fiber tube.

3. The method for preparing the composite material hydraulic cylinder barrel according to claim 1, characterized in that, In step S4, the fabrication of the bottom metal part and the top metal part containing the sealing groove includes the following sub-steps: S411. Process and manufacture according to the dimensions designed in the drawings to obtain metal blanks; S412. The outer surface of the metal blank is subjected to degreasing and sandblasting roughening treatment; S413. A sealing groove is provided on the metal blank to form the bottom metal part and the top metal part.

4. The method for preparing the composite material hydraulic cylinder barrel according to claim 1, characterized in that, Step S4 also includes preparing the second mandrel mold, specifically including the following sub-steps: S421. Machining according to the dimensions designed in the drawings to obtain the mandrel blank; S422. Grind the outer surface of the mandrel blank to reduce the surface roughness of the mandrel blank and form the second mandrel mold.

5. The method for preparing the composite material hydraulic cylinder barrel according to claim 1, characterized in that, One end of the bottom metal part is provided with a first step and a second step. The first step is provided with two sealing grooves, and the second step is provided with one sealing groove.

6. The method for preparing the composite material hydraulic cylinder barrel according to claim 1, characterized in that, The top metal part is provided with two sealing grooves.

7. The method for preparing the composite material hydraulic cylinder barrel according to claim 1, characterized in that, Step S1 further includes preparing the first mandrel mold, specifically including: turning according to the design dimensions in the drawing to obtain a mandrel blank; grinding the outer surface of the mandrel blank to reduce the surface roughness of the mandrel blank, and forming the first mandrel mold.

8. A composite material hydraulic cylinder barrel, characterized in that, The composite hydraulic cylinder barrel is prepared according to any one of claims 1-7.

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