A composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator

Abstract

The present invention relates to a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, belongs to the field of sealing technology, and is used to solve the problem that the sealing layer of an existing actuator is not pressure-resistant or the glue penetrates into the internal and related parts of the actuator. The method comprises: cleaning the surface of the part to be sealed and the surface of the sealing tool; applying silicone rubber to the outlet hole of the angular displacement sensor, and after the silicone rubber is applied, standing to allow the silicone rubber to solidify to form a silicone rubber sealing area; installing the sealing tool; starting a high-temperature test chamber; placing polyether polyurethane in the high-temperature test chamber for heating; taking out the polyether polyurethane after heating and placing it in a vacuum chamber for degassing treatment; mixing diaminodiphenylmethane with polyether polyurethane; placing the mixed glue in a vacuum drying chamber for degassing treatment; injecting the mixed glue into the area to be sealed; standing to complete the sealing. The actuator sealed by the composite layered sealing method of the present invention can withstand an air pressure of 0.2Mpa, and can also effectively prevent low-viscosity glue from penetrating into the interior of the actuator.

Description

Technical Field

[0001] The invention relates to the technical field of sealing, and in particular to a composite layered sealing method for preventing low-viscosity glue from penetrating into an actuator. Background Art

[0002] The actuator drives the load to reciprocate through four shafts. The actuator cabin relies on the actuator to drive the load to work and achieve the function of changing direction.

[0003] In order to fix a cable, the actuator needs to be sealed as a whole in the cabin, which requires the actuator part in the cabin to be sealed. Because the actuator has many parts, it is impossible to have high sealing performance while meeting the requirements of the use environment (such as quality, space, etc.). For example, the internal sensor outlet hole and other locations will cause the seal to fail, which will cause the sealant to penetrate into the actuator. After the penetrated glue solidifies, it will seriously affect the operation of the actuator and even cause the actuator to fail. Therefore, it is necessary to seal certain parts of the actuator in advance. According to the use environment of the execution cabin, there are some basic requirements for the characteristics of the sealing materials of the actuator: first, the cured sealing material should be non-corrosive and have good adhesion. The bonding performance with metal parts can adapt to the environmental test conditions of the execution cabin, such as vibration, impact, high and low temperature, humidity, acceleration, low air pressure, etc., and can withstand various tests without interface separation; the mechanical properties require that the sealing material must have a certain tensile strength; because the actuator is sealed in the cabin using a process method of vacuuming and injecting glue at the same time, the pre-formed sealing part of the actuator should also be able to withstand a pressure of 0.2MPa.

[0004] Due to the space limitation in the actuator, the existing sealing materials often have the risk of the sealing layer not being pressure-resistant or the glue penetrating into the related parts inside the actuator, thus affecting the operation of the moving parts. Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of the actuator, which can solve the problem that the existing actuator sealing layer is not pressure-resistant or the glue penetrates into the internal related parts of the actuator, resulting in the risk of affecting the movement of the moving parts.

[0006] In one aspect, the present invention provides a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, comprising:

[0007] Step 1: Clean the surface of the part to be sealed and the surface of the sealing tooling;

[0008] Step 2: Apply GD414 silicone rubber to the outlet hole of the angular displacement sensor, but do not allow the GD414 silicone rubber to flow to the central wire hole. After applying the GD414 silicone rubber, let it stand until the GD414 silicone rubber solidifies to form a GD414 silicone rubber sealing area.

[0009] Step 3: Install the sealing tool. The sealing tool includes a cylinder and a square plate. The cylinder is a cylinder with a smooth surface and a threaded end. The square plate has a threaded hole in the middle. First, apply 7501 vacuum silicone grease evenly to the outer surface of the cylinder, then insert the cylinder into the central wire hole, and use the square plate to tighten and fix the cylinder.

[0010] Step 4: Check that the electronic scale, high temperature test chamber, and vacuum chamber are functioning normally, and start the high temperature test chamber;

[0011] Step 5, placing the polyether polyurethane in a high temperature test box and heating it to 70-75° C. and maintaining it for 10-20 minutes;

[0012] Step 6, after heating, take out the polyether polyurethane and put it into a vacuum box for degassing;

[0013] Step 7, mixing diaminodiphenylmethane with polyether polyurethane to obtain a mixed glue solution;

[0014] Step 8, placing the mixed glue solution into a vacuum drying oven for degassing;

[0015] Step 9. After degassing, take out the mixed glue liquid, use a syringe to draw the mixed glue liquid and inject it into the area to be sealed where the sealing tooling has been installed, and form a complete mixed glue liquid sealing layer; let the mixed glue liquid stand to solidify to form a mixed glue liquid sealing area, and complete the sealing.

[0016] Furthermore, in step 1, use tweezers to hold alcohol cotton to clean the surface of the part to be sealed and the surface of the sealing tooling.

[0017] Furthermore, in step 2, a small needle is used to pick up GD414 silicone rubber for application.

[0018] Furthermore, in step 2, the GD414 silicone rubber is allowed to stand for 5 to 7 hours to solidify.

[0019] Furthermore, in step 6, the degassing treatment is carried out in a vacuum drying oven at a vacuum degree of not less than 98.7 kPa for 2 to 3 times.

[0020] Furthermore, if there are no bubbles in the glue solution visually, it is determined that the degassing process is completed.

[0021] Furthermore, in step 7, the mass ratio of polyether polyurethane to diaminodiphenylmethane is controlled to be 4 to 6:1.

[0022] Furthermore, the mass ratio of GD414 silicone rubber to the mixed rubber solution is 1:9-10.

[0023] Furthermore, in step 9, the mixed adhesive is allowed to solidify by standing for 24 to 36 hours.

[0024] Furthermore, in step 8, the degassing treatment is carried out in a vacuum drying oven at a vacuum degree of not less than 98.7 kPa for 2 to 3 times.

[0025] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0026] The composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of the actuator of the present invention adopts the method of first coating GD414 silicone rubber, and then coating the mixed glue of diamine diphenylmethane and polyether polyurethane on the outside of the GD414 silicone rubber, and by accurately controlling the process parameters of each step to ensure that the mixed glue of diamine diphenylmethane and polyether polyurethane covers the GD414 silicone rubber, which can effectively prevent the low-viscosity glue from penetrating into the interior of the actuator in a small space, thereby reducing the failure rate of the actuator after being loaded; and the actuator sealed by the composite layered sealing method of the present invention can withstand an air pressure of 0.2Mpa. The failure rate of the actuator after being loaded is greatly reduced, saving a lot of manpower and material costs.

[0027] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0029] Figure 1 It is a structural schematic diagram of the actuator of the present invention;

[0030] Figure 2 This is a diagram showing the effect of the actuator of the present invention after sealing.

[0031] Reference numerals:

[0032] 1-frame, 2-motor, 3-shaft, 4-angular displacement sensor, 5-wire outlet hole of angular displacement sensor, 6-central wire hole, 7-cylinder, 8-square plate, 9-GD414 silicone rubber sealing area, 10-mixed glue sealing area. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0034] like Figure 1 As shown, the actuator of the present invention mainly includes a frame 1, a motor 2, a rotating shaft 3 and an angular displacement sensor 4; wherein the angular displacement sensor 4 is installed on the rotating shaft 3, the rotating shaft 3 is installed in the bearing hole of the frame 1, the angular displacement sensor 4 is close to the inner wall of the frame, and an angular displacement sensor outlet hole 5 is provided on the inner wall of the frame, and the angular displacement sensor outlet hole 5 is used for the signal line outlet of the angular displacement sensor 4; a central wire hole 6 is also provided on the frame 1; during the assembly process, the inner walls of the angular displacement sensor outlet hole 5 and the central wire hole 6 need to be sealed to block the passage between the outside and the cavity, and at the same time, the cable passage channel cannot be blocked.

[0035] It should be noted that the sealed area is a circular ring with an outer diameter of 13 to 14 mm, an inner diameter of 8 to 9 mm, and a height of 19 to 21 mm. The space is very small and it is impossible to complete a sealing process that meets the requirements using existing processes.

[0036] The present invention provides a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, comprising:

[0037] Step 1: Clean the surface of the part to be sealed and the surface of the sealing tooling;

[0038] Step 2: Use a small needle to pick up GD414 silicone rubber and apply it to the angular displacement sensor outlet hole 5. However, the GD414 silicone rubber cannot flow to the central wire hole 6. A 1-2 mm space must be reserved in the radial direction from the central wire hole to the inner wall of the frame. After the GD414 silicone rubber is applied, let it stand until the GD414 silicone rubber solidifies to form the GD414 silicone rubber sealing area 9.

[0039] Step 3, install the sealing tool, which includes a cylinder 7 and a square plate 8. The cylinder 7 is a cylinder with a smooth surface and an M6 thread on one end with a diameter of 8.5 mm. The square plate 8 is provided with an M6 threaded hole in the middle. First, evenly apply 7501 vacuum silicone grease (as a release agent) to the outer surface of the cylinder 7, then insert the cylinder 7 into the central wire hole 6, and use the square plate 8 to tighten and fix the cylinder 7.

[0040] Step 4: Check that the electronic scale, high temperature test chamber, and vacuum chamber are functioning normally, and start the high temperature test chamber;

[0041] Step 5, placing the polyether polyurethane in a high temperature test box and heating it to 70-75° C. and maintaining it for 10-20 minutes;

[0042] Step 6, after heating, take out the polyether polyurethane and put it into a vacuum box for 2 to 3 times of degassing treatment;

[0043] Step 7, mixing diaminodiphenylmethane with polyether polyurethane to obtain a mixed glue solution;

[0044] Step 8: Place the mixed glue solution in a vacuum drying oven for degassing 2 to 3 times;

[0045] Step 9. After degassing, take out the mixed glue. Because the sealing space is small, use a syringe to draw the mixed glue and inject it into the area to be sealed where the sealing tool has been installed; inject slowly and expel the air to ensure that the mixed glue covers the GD414 silicone rubber sealing area 9 and forms a complete mixed glue sealing layer; let the mixed glue stand to solidify to form a mixed glue sealing area 10 to complete the sealing.

[0046] Specifically, in the above step 1, tweezers can be used to hold alcohol cotton to clean the surface of the part to be sealed and the surface of the sealing tooling.

[0047] Specifically, in the above step 2, due to the limitation of the coating space, a small needle is needed to pick up the GD414 silicone rubber for coating.

[0048] Specifically, in the above step 2, if the standing time is too long, the sealing production cycle will be too long, increasing the time cost; if the standing time is too short, the silicone rubber will not be fully cured and the strength will be insufficient, and it will not be able to effectively block the mixed glue on the upper layer. Therefore, the standing time is controlled to be 5 to 7 hours to allow the GD414 silicone rubber to cure.

[0049] Specifically, in the above step 3, the square plate 8 is a square plate with a thickness of 8 to 10 mm and a side length of (60 to 62) mm×(60 to 62) mm.

[0050] Specifically, in the above step 5, if the heating temperature is too high or the heating time is too long, the polyether polyurethane may be easily oxidized; if the heating temperature is too low, the glue liquid may not reach the reaction temperature during mixing and the glue liquid may not fully react; if the heating time is too short, the glue liquid may not be heated to the required temperature. Therefore, the temperature is controlled to be 70-75°C and maintained for 10-20 minutes.

[0051] Specifically, in the above step 6, the degassing treatment is carried out in a vacuum drying oven at a vacuum degree of not less than 98.7 kPa for 2 to 3 times. If there are no bubbles in the glue solution visually, it is determined that the degassing treatment is completed.

[0052] Specifically, in the above step 7, the container containing the polyether polyurethane is placed on an electronic scale, and a corresponding proportion of diaminodiphenylmethane is slowly poured into the container, and after mixing, it is stirred with a glass rod for 2 to 5 minutes.

[0053] Specifically, in the above step 7, considering that a too high mass ratio of polyether polyurethane to diamine diphenylmethane will make the mixed glue difficult to solidify, and a too low mass ratio will make the glue solidify too quickly and there will be no operating window period for operating the sealing work, therefore, the mass ratio of polyether polyurethane to diamine diphenylmethane is controlled to be 4 to 6:1.

[0054] Specifically, in the above step 8, the degassing treatment is carried out in a vacuum drying oven under the condition of a vacuum degree of not less than 98.7 kPa for 2 to 3 times, and the degassing treatment is determined to be completed when there are no bubbles in the glue solution visually.

[0055] Specifically, if the mass ratio of the above-mentioned GD414 silicone rubber to the mixed glue is too high, the GD414 glue will flow excessively to the central wire hole, thereby making it impossible for the mixed glue to form a closed seal, and the seal failure may occur easily. If the mass ratio of GD414 silicone rubber to the mixed glue is too low, the amount of GD414 silicone rubber is too small, and the polyurethane glue cannot be prevented from invading the internal cavity of the actuator. Therefore, the mass ratio of GD414 silicone rubber to the mixed glue is controlled to be 1:9~10.

[0056] Specifically, in the above step 9, if the standing time is too long, the production cycle will be too long, while if it is too short, the mixed colloid will not be completely solidified, and then the colloid will tear when the sealing tool is removed, resulting in the failure of the sealing operation. Therefore, the mixed glue is allowed to stand for 24 to 36 hours to solidify.

[0057] Specifically, in the above step 9, after the sealing is completed, the side close to the angular displacement sensor outlet hole 5 is the GD414 silicone rubber sealing area 9 with a length of 2.8 to 3 mm, and the side close to the cylinder 7 is the mixed glue sealing area 10 with a height of 20 to 25 mm and a thickness of 2.2 to 2.5 mm. In this way, it can be ensured that the GD414 silicone rubber forms a sealing layer inside to prevent the mixed glue from invading the internal cavity of the actuator; the polyurethane mixed glue can form a complete sealing layer to prevent the low-viscosity glue from invading, and can withstand an air pressure of 0.2 MPa.

[0058] Specifically, after the sealing is completed in step 9 above, the actuator is pressure tested, and the sealing effect is tested using a pressure-resistant tooling to ensure that it can withstand an air pressure of 0.2 MPa.

[0059] Example 1

[0060] This embodiment provides a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, comprising:

[0061] Step 1: Use tweezers to pick up alcohol cotton and clean the surface of the part to be sealed and the surface of the sealing tooling;

[0062] Step 2: Use a small needle to pick up GD414 silicone rubber and apply it to the root of the sensor wire inside the actuator to seal the wire outlet hole, and let it stand for 6 hours until the GD414 silicone rubber solidifies to form a GD414 silicone rubber sealing area 9;

[0063] Step 3, install the sealing tool; the sealing tool includes a cylinder 7 and a square plate 8. The cylinder 7 is a cylinder with a diameter of 8.5 mm and a smooth surface and an M6 thread at one end. The square plate 8 is provided with an M6 threaded hole in the middle. First, evenly apply 7501 vacuum silicone grease (as a release agent) to the outer surface of the cylinder 7, then insert the cylinder 7 into the central wire hole 6, and use the square plate 8 to tighten and fix the cylinder 7.

[0064] Step 4: Check that the electronic scale, high temperature test chamber, and vacuum chamber are functioning normally, and start the high temperature test chamber;

[0065] Step 5, heat the polyether polyurethane in a high temperature test box to 70°C and keep it for 15 minutes;

[0066] Step 6, after heating, take out the polyether polyurethane and put it into a vacuum box for two degassing treatments under the condition of vacuum degree not less than 98.7 kPa;

[0067] Step 7, placing the container containing polyether polyurethane on an electronic scale, slowly pouring diamine diphenylmethane into the container, stirring with a glass rod after mixing, stirring for 2 minutes, to obtain a mixed glue solution; the mass ratio of polyether polyurethane to diamine diphenylmethane is 4:1;

[0068] Step 8, placing the mixed glue solution into a vacuum drying oven and degassing it twice under the condition of a vacuum degree of not less than 98.7 kPa;

[0069] Step 9. After degassing, take out the mixed glue. Because the sealing space is small, use a syringe to absorb the mixed glue and inject it into the area to be sealed where the sealing tool has been installed. Inject slowly and exhaust the air to ensure that the mixed glue covers the GD414 silicone rubber sealing area 9 and forms a complete mixed glue sealing layer. Let the mixed glue stand to solidify to form the mixed glue sealing area 10 to complete the sealing. The mass ratio of GD414 silicone rubber to mixed glue is 1:9.5.

[0070] like Figure 2 The figure shows the effect of the actuator after sealing. After the sealing is completed, the side close to the angular displacement sensor outlet hole 5 is the GD414 silicone rubber sealing area 9, which is about 3 mm in length, and the side close to the cylinder 7 is the mixed glue sealing area 10, which is about 20 mm in height and about 2.5 mm in thickness.

[0071] After the sealing is completed, the actuator is pressure tested and the sealing effect is tested using a pressure-resistant tooling, which can withstand 0.2MPa air pressure.

[0072] Example 2

[0073] This embodiment provides a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, comprising:

[0074] Step 1: Use tweezers to pick up alcohol cotton and clean the surface of the part to be sealed and the surface of the sealing tooling;

[0075] Step 2: Use a small needle to pick up GD414 silicone rubber and apply it to the root of the sensor wire inside the actuator to seal the wire outlet hole, and let it stand for 7 hours to allow the GD414 silicone rubber to solidify to form a GD414 silicone rubber sealing area 9;

[0076] Step 3, install the sealing tool: The sealing tool includes a cylinder 7 and a square plate 8. The cylinder 7 is a cylinder with a diameter of 8.5 mm and a smooth surface and an M6 thread at one end. The square plate 8 is provided with an M6 threaded hole in the middle. First, evenly apply 7501 vacuum silicone grease (as a release agent) to the outer surface of the cylinder 7, then insert the cylinder 7 into the central wire hole 6, and use the square plate 8 to tighten and fix the cylinder 7.

[0077] Step 4: Check that the electronic scale, high temperature test chamber, and vacuum chamber are functioning normally, and start the high temperature test chamber;

[0078] Step 5, heat the polyether polyurethane in a high temperature test box to 73°C and maintain for 20 minutes;

[0079] Step 6, after heating, take out the polyether polyurethane and put it into a vacuum box for three degassing treatments under the condition of vacuum degree not less than 98.7 kPa;

[0080] Step 7, placing the container containing polyether polyurethane on an electronic scale, slowly pouring diamine diphenylmethane into the container, stirring with a glass rod after mixing, stirring for 2 minutes, to obtain a mixed glue solution; the mass ratio of polyether polyurethane to diamine diphenylmethane is 5.5:1;

[0081] Step 8, placing the mixed glue solution into a vacuum drying oven and degassing it twice under the condition of a vacuum degree of not less than 98.7 kPa;

[0082] Step 9. After degassing, take out the mixed glue. Because the sealing space is small, use a syringe to absorb the mixed glue and inject it into the sealing area where the sealing tooling has been installed. Inject slowly and exhaust air to ensure that the mixed glue covers the GD414 silicone rubber sealing area 9 and forms a complete mixed glue sealing layer. Let the mixed glue stand to solidify to form the mixed glue sealing area 10 to complete the sealing. The mass ratio of GD414 silicone rubber to mixed glue is 1:9.

[0083] After the sealing is completed, the side close to the angular displacement sensor outlet hole 5 is the GD414 silicone rubber sealing area 9, which is about 2.8 mm long, and the side close to the cylinder 7 is the mixed glue sealing area 10, which is about 23 mm high and about 2.5 mm thick.

[0084] After the sealing is completed, the actuator is pressure tested and the sealing effect is tested using a pressure-resistant tooling, which can withstand 0.2MPa air pressure.

[0085] Comparative Example 1

[0086] This comparative example provides a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, comprising:

[0087] Step 1: Use tweezers to pick up alcohol cotton and clean the surface of the part to be sealed and the surface of the sealing tooling;

[0088] Step 2, install the sealing tool; the sealing tool includes a cylinder 7 and a square plate 8. The cylinder 7 is a cylinder with a smooth surface and an M6 thread on one end with a diameter of 8.5 mm. The square plate 8 is provided with an M6 threaded hole in the middle. First, evenly apply 7501 vacuum silicone grease (as a release agent) to the outer surface of the cylinder 7, then insert the cylinder 7 into the central wire hole 6, and use the square plate 8 to tighten and fix the cylinder 7.

[0089] Step 3: Check that the electronic scale, high temperature test chamber, and vacuum chamber are functioning normally, and start the high temperature test chamber;

[0090] Step 4, heat the polyether polyurethane in a high temperature test box to 70°C and keep it for 15 minutes;

[0091] Step 5, after heating, take out the polyether polyurethane and put it into a vacuum box for degassing twice;

[0092] Step 6, placing the container containing polyether polyurethane on an electronic scale, slowly pouring diamine diphenylmethane into the container, stirring with a glass rod after mixing, stirring for 5 minutes, to obtain a mixed glue solution; the mass ratio of polyether polyurethane to diamine diphenylmethane is 4:1;

[0093] Step 7, put the mixed glue solution into a vacuum drying oven for degassing twice;

[0094] Step 8. After degassing, take out the mixed glue. Because the sealing space is small, use a syringe to draw the mixed glue and inject it into the area to be sealed where the sealing tooling has been installed. Inject slowly and form a complete mixed glue sealing layer. Let the mixed glue stand to solidify and complete the sealing.

[0095] After the seal is completed, the actuator is pressure tested, and the sealing effect is tested using a pressure-resistant tooling, which can withstand 0.2MPa air pressure. After removing the shaft, it is found that the mixed glue has invaded the cavity where the shaft is located, and there is a hidden danger that the sealing mixed glue will affect the transmission parts. Once the mixed glue invades the cavity and adheres to the shaft, the actuator function will fail.

[0096] Comparative Example 2

[0097] This comparative example provides a composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, comprising:

[0098] Step 1: Use tweezers to pick up alcohol cotton and clean the surface of the part to be sealed and the surface of the sealing tooling;

[0099] Step 2: Use a small needle to pick up GD414 silicone rubber and apply it to the root of the sensor wire inside the actuator to seal the wire outlet hole, and let it stand for 6 hours to allow the GD414 silicone rubber to cure;

[0100] Step 3, install the sealing tool; the sealing tool includes a cylinder 7 and a square plate 8. The cylinder 7 is a cylinder with a diameter of 8.5 mm and a smooth surface and an M6 thread at one end. The square plate 8 is provided with an M6 threaded hole in the middle. First, evenly apply 7501 vacuum silicone grease (as a release agent) to the outer surface of the cylinder 7, then insert the cylinder 7 into the central wire hole 6, and use the square plate 8 to tighten and fix the cylinder 7.

[0101] Step 4: Check that the electronic scale, high temperature test chamber, and vacuum chamber are functioning normally, and start the high temperature test chamber;

[0102] Step 5, heat the polyether polyurethane in a high temperature test box to 50°C and keep it for 5 minutes;

[0103] Step 6, after heating, take out the polyether polyurethane and put it into a vacuum box for degassing twice;

[0104] Step 7, placing the container containing polyether polyurethane on an electronic scale, slowly pouring diamine diphenylmethane into the container, stirring with a glass rod after mixing, stirring for 10 minutes, to obtain a mixed glue solution; the mass ratio of polyether polyurethane to diamine diphenylmethane is 6.5:1;

[0105] Step 8: Place the mixed glue solution in a vacuum drying oven for degassing twice;

[0106] Step 9. After degassing, take out the mixed glue. Because the sealing space is small, use a syringe to absorb the mixed glue and inject it into the sealed area where the sealing tooling has been installed. Inject slowly and expel air to ensure that the mixed glue covers the GD414 silicone rubber and forms a complete mixed glue sealing layer.

[0107] After standing, the glue was not completely solidified. The actuator was pressure tested and the sealing effect was tested using a pressure-resistant tooling. It was found that it could not withstand 0.2MPa air pressure.

[0108] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A composite layered sealing method for preventing low-viscosity glue from penetrating into the interior of an actuator, characterized in that: include: Step 1: Clean the surface of the part to be sealed and the surface of the sealing tooling; Step 2: Apply GD414 silicone rubber to the angular displacement sensor outlet hole (5), but do not allow the GD414 silicone rubber to flow to the central wire hole (6). After applying the GD414 silicone rubber, let it stand until the GD414 silicone rubber solidifies to form a GD414 silicone rubber sealing area (9). Step 3, installing the sealing tool, the sealing tool comprises a cylinder (7) and a square plate (8), the cylinder (7) is a cylinder with a smooth surface and a threaded end, and a threaded hole is provided in the middle of the square plate (8); first, 7501 vacuum silicone grease is evenly applied to the outer surface of the cylinder (7), and then the cylinder (7) is inserted into the central wire hole (6), and the square plate (8) is used to tighten and fix the cylinder (7); Step 4: Check that the electronic scale, high temperature test chamber, and vacuum chamber are functioning normally, and start the high temperature test chamber; Step 5, placing the polyether polyurethane in a high temperature test box and heating it to 70-75° C. and maintaining it for 10-20 minutes; Step 6, after heating, take out the polyether polyurethane and put it into a vacuum box for degassing; Step 7, mixing diaminodiphenylmethane with polyether polyurethane to obtain a mixed glue solution; Step 8, placing the mixed glue solution into a vacuum drying oven for degassing; Step 9: After degassing, take out the mixed glue liquid, use a syringe to draw the mixed glue liquid and inject it into the area to be sealed where the sealing tool has been installed, and form a complete mixed glue liquid sealing layer; let the mixed glue liquid stand to solidify to form a mixed glue liquid sealing area (10), and complete the sealing.

2. The composite layered sealing method according to claim 1, characterized in that: In step 1, use tweezers to hold alcohol cotton to clean the surface of the part to be sealed and the surface of the sealing tooling.

3. The composite layered sealing method according to claim 1, characterized in that: In step 2, a small needle is used to pick up GD414 silicone rubber for application.

4. The composite layered sealing method according to claim 1, characterized in that: In the step 2, the GD414 silicone rubber is allowed to stand for 5 to 7 hours to solidify.

5. The composite layered sealing method according to claim 1, characterized in that: In the step 6, the degassing treatment is carried out in a vacuum drying oven for 2 to 3 times under the condition of a vacuum degree of not less than 98.7 kPa.

6. The composite layered sealing method according to claim 5, characterized in that: If there are no bubbles in the glue solution, the degassing process is considered complete.

7. The composite layered sealing method according to claim 1, characterized in that: In the step 7, the mass ratio of polyether polyurethane to diaminodiphenylmethane is controlled to be 4-6:

1.

8. The composite layered sealing method according to claim 1, characterized in that: The mass ratio of the GD414 silicone rubber to the mixed glue solution is 1:9-10.

9. The composite layered sealing method according to claim 1, characterized in that: In step 9, the mixed glue is allowed to solidify by standing for 24 to 36 hours.

10. The composite layered sealing method according to any one of claims 1 to 9, characterized in that: In the step 8, the degassing treatment is carried out in a vacuum drying oven for 2 to 3 times under the condition of a vacuum degree of not less than 98.7 kPa.

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