Steel sleeve and press fitting process

Abstract

According to the steel sleeve and the press-fitting process, an oil guide structure is arranged on the circumference of the steel sleeve, glue containing grooves which are annularly distributed by 360 degrees are formed in the outer surface of the circumference of the steel sleeve, and the outer surface of the circumference of the steel sleeve is divided into a first area on the upper portion and a second area on the lower portion by the glue containing grooves with the glue containing grooves as boundaries; the oil guide structure is located in the second area; the first area comprises a gluing area and a blank area, and the gluing area does not exist above the oil guide structure. According to the invention, the glue solution is smeared on the gluing area on the outer circumferential surface of the steel sleeve, the glue solution and the steel sleeve are pressed into the bearing hole of the end cover together, the adhesion effect of the glue solution can effectively improve the connection force between the steel sleeve and the end cover and improve the maximum push-out force, and the glue containing groove has the storage function of the glue solution, so that to a certain extent, the service life of the steel sleeve is prolonged. The requirements for the glue solution smearing action and the glue brushing amount are lowered, even if the glue solution smearing amount is increased, redundant glue solution can be stored in the glue containing groove and cannot flow into the second area, and the potential safety hazard that the oil guide structure is blocked is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of steel sleeve assembly, and in particular relates to a steel sleeve and a press-fitting process. Background Art

[0002] The end cover of the electric drive of new energy electric vehicles needs to be installed with a steel sleeve, which is located in the bearing hole of the end cover. The main purpose of installing the steel sleeve is to ensure the assembly quality and lightweight requirements of the product after the bearing is installed and operated.

[0003] The traditional method of installing a steel sleeve mainly adopts a simple thermal assembly process, which heats the end cover to enlarge the bearing hole, and then embeds the steel sleeve into the bearing hole. After the end cover cools and shrinks, the assembly of the steel sleeve and the end cover is completed.

[0004] The above-mentioned traditional thermal assembly process has the following technical problems:

[0005] When carrying out a push-out force test on the assembled steel sleeve, it was found that the maximum push-out force required for the steel sleeve to maintain a stable position did not meet the standard. This means that under certain load conditions, the position of the steel sleeve itself cannot be guaranteed, and the steel sleeve itself is at risk of displacement or even falling out. Therefore, this poses a huge safety hazard to the safe operation of new energy electric vehicles.

[0006] To this end, a steel sleeve and a press-fitting process are provided to ensure the stability of the steel sleeve after press-fitting and to increase the maximum push-out force of the steel sleeve in the end cover. Summary of the invention

[0007] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a steel sleeve and a press-fitting process.

[0008] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention provides a steel sleeve, wherein an oil guide structure is provided on the circumference of the steel sleeve, and a 360° annularly distributed glue containing groove is provided on the circumferential outer surface of the steel sleeve, and the circumferential outer surface of the steel sleeve is divided into a first area on the top and a second area on the bottom by the glue containing groove with the glue containing groove as a boundary;

[0010] The oil guiding structure is located in the second area;

[0011] The first area includes a glue-coated area and a blank area, and there is no glue-coated area above the oil guide structure.

[0012] The present invention applies glue on the glue coating area of ​​the outer circumferential surface of the steel sleeve, and presses the glue and the steel sleeve into the bearing hole of the end cover. The adhesive effect of the glue itself can effectively improve the connection force between the steel sleeve and the end cover, maintain the stability of the steel sleeve in the end cover, and improve the maximum push-out force during the push-out force test.

[0013] The present invention divides the outer circumferential surface of the steel sleeve by the glue containing groove to form a first area on the top and a second area on the bottom, and the oil guide structure is in the second area on the bottom. The glue liquid only exists in the glue coating area of ​​the first area. The advantage of this is that the glue liquid and the oil guide structure are separated by the glue containing groove as the boundary, and the glue liquid is prevented from flowing into the oil guide structure, causing the oil guide structure to be blocked by the solidified glue liquid, and the lubricating liquid cannot smoothly enter the interior through the oil guide structure to achieve lubrication. In addition, the glue containing groove also has the storage function of the glue liquid, which to a certain extent reduces the requirements for the glue liquid application action and the amount of glue brushing. Even if the amount of glue liquid applied is increased, the excess glue liquid can be stored in the glue containing groove, and will not flow into the second area, causing the safety hazard of clogging the oil guide structure.

[0014] In the first area of ​​the present invention, in addition to the glue coating area, a blank area is additionally provided. The blank area is located directly above the oil guide structure and can cover the oil guide structure in the circumferential direction. This is to prevent the glue from accidentally draining down and blocking the oil guide structure by reserving a blank position. If the first area directly above the oil guide structure is also coated with glue, when the coating action is wrong and the amount of glue is abnormally excessive and exceeds the volume of the glue tank, the glue will drain down under the action of gravity and directly enter the oil guide structure.

[0015] In a second aspect, the present invention provides a press-fitting process for press-fitting a steel sleeve as described in the first aspect, comprising the following steps:

[0016] S1. Apply glue to the glue coating area in the first area divided by the glue tank;

[0017] S2. Heating the object pressed into the steel sleeve;

[0018] S3. Press-fit the steel sleeve;

[0019] S4. After being pressed into place, it is cooled.

[0020] In the present invention, the object pressed into the steel sleeve is not limited to the end cover in the electric drive of the new energy electric vehicle, but is also applicable to other objects that need to be installed in the steel sleeve;

[0021] The present invention applies glue to the glue coating area on the outer circumferential surface of the steel sleeve, and presses the glue and the steel sleeve into the bearing hole of the end cover together. Under the adhesion effect of the glue itself, the connection force between the steel sleeve and the end cover can be effectively improved, and the stability of the steel sleeve in the end cover can be maintained;

[0022] The glue is only applied to the glue coating area, and the excess glue flowing downward is intercepted and stored in the glue storage tank to prevent the glue from flowing to the area that cannot be coated.

[0023] As a preferred technical solution of the present invention, when applying glue to the glue coating area, the glue brush adhering the glue remains stationary, and the steel sleeve is driven by the motor to rotate at a set angle relative to the glue brush to achieve the application action.

[0024] The present invention specifically stipulates that a motor is used as the power to drive the steel sleeve to rotate, because the motor is very easy to control and has high precision. When applying the glue, only the glue coating area needs to be covered. Therefore, the circular angle of the glue coating on the surface of the steel sleeve must be guaranteed. Motor control is a very ideal and mature solution. It elevates the coating action to an automated and controllable level. Under the premise of determining that the motor drives the cylinder sleeve to rotate, the glue brush only needs to remain stationary, that is, it can move relative to the cylinder sleeve to complete the coating action.

[0025] As a preferred technical solution of the present invention, when applying the glue, a CCD visual camera is used to take a picture of the outer circumferential surface of the steel sleeve, and the distribution range of the glue in the image is analyzed to determine whether it is qualified.

[0026] The present invention particularly limits the way of detecting and providing feedback on the coating quality. The present invention adopts a CCD visual camera to take pictures of the outer circumferential surface of the steel sleeve. By analyzing whether the distribution of the glue in the captured image conforms to the preset position and area, it can be judged whether the coating action is qualified, thereby avoiding the lack of monitoring feedback, which leads to the continued circulation of defective products on the production line, causing greater economic losses and hidden dangers in use.

[0027] As a preferred technical solution of the present invention, the object pressed into the steel sleeve is heated in the form of an electric heating tube, heated to a temperature range of 130 to 150°C, an infrared thermometer is used to detect the heating temperature, and a temperature controller is used to control the heating temperature of the electric heating tube.

[0028] The present invention specifically stipulates that heating is performed in the form of an electric heating tube and the temperature is controlled by a temperature controller because the electric heating tube has an extremely long service life and is convenient for subsequent maintenance. In addition, the heating capacity of the electric heating tube can also well adapt to the heating requirements of 130 to 150°C. The temperature range of 130 to 150°C can provide sufficient deformation space for the bearing hole of the end cover to ensure smooth assembly. The infrared thermometer can monitor the heating and cooling temperatures.

[0029] In some optional instances, the temperature range is 130-150°C, for example, it can be 130°C, 131°C, 132°C, 133°C, 134°C, 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, 141°C, 142°C, 143°C, 144°C, 145°C, 146°C, 147°C, 148°C, 149°C or 150°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] As a preferred technical solution of the present invention, the steel sleeve and the object pressed into the steel sleeve are cooled by blowing gas, and the temperature needs to be cooled to below 60°C.

[0031] The present invention particularly limits the cooling method. The present invention adopts the blowing method to accelerate the flow of air, change the heat distribution between the air and the surface of the steel sleeve and the end cover. After heat transfer, the air with increased temperature is continuously sent away, and the gas with lower temperature in nature is continuously sent in, which accelerates the loss of heat on the surface of the steel sleeve and the end cover, so as to achieve the purpose of fast and low-cost cooling. Cooling can also accelerate the solidification of the glue, so that the combination efficiency of the steel sleeve and the end cover is higher.

[0032] Beneficial effects of the present invention:

[0033] 1. The present invention applies glue on the glue coating area on the outer circumferential surface of the steel sleeve, and presses the glue and the steel sleeve into the bearing hole of the end cover. The adhesive effect of the glue itself can effectively improve the connection force between the steel sleeve and the end cover, maintain the stability of the steel sleeve in the end cover, and improve the maximum push-out force during the push-out force test, thereby providing reliable protection for the safe operation of new energy electric vehicles;

[0034] 2. The present invention divides the outer circumferential surface of the steel sleeve by the glue containing groove to form a first area on the top and a second area on the bottom. The oil guide structure is in the second area on the bottom. The glue liquid only exists in the glue coating area of ​​the first area. The advantage of this is that the glue liquid and the oil guide structure are separated by the glue containing groove as the boundary, and the glue liquid is prevented from flowing into the oil guide structure, causing the oil guide structure to be blocked by the solidified glue liquid, and the lubricating liquid cannot smoothly enter the interior through the oil guide structure to achieve lubrication. In addition, the glue containing groove also has the storage function of the glue liquid, which to a certain extent reduces the requirements for the glue liquid application action and the amount of glue brushing. Even if the amount of glue liquid applied is increased, the excess glue liquid can be stored in the glue containing groove, and will not flow into the second area, causing the safety hazard of clogging the oil guide structure;

[0035] 3. In addition to setting up a glue coating area, the present invention also additionally sets up a blank area in the first area. The blank area is located directly above the oil guiding structure and can cover the oil guiding structure in the circumferential direction. This is to reserve a blank position to prevent the glue from accidentally draining down and causing the oil guiding structure to be blocked. If the first area directly above the oil guiding structure is also coated with glue, when the coating action goes wrong and the amount of glue is abnormally excessive and exceeds the capacity of the glue containing groove, the glue will drain down under the action of gravity and directly enter the oil guiding structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0037] Figure 1 It is a front view of an embodiment of the present invention;

[0038] Figure 2 A top view of an embodiment of the present invention;

[0039] Figure 3 A three-dimensional diagram of an embodiment of the present invention;

[0040] Figure 4 For the embodiment of the present invention Figure 1 A partial enlarged view of the middle A;

[0041] Figure 5 For the embodiment of the present invention Figure 3 A partial enlarged view of point B in the middle;

[0042] Figure 6 This is a result diagram of a push-out force test performed on Comparative Example 1 of the present invention;

[0043] Figure 7 This is a diagram showing the result of a push-out force test performed on Example 5 of the present invention;

[0044] The main component symbols are described as follows:

[0045] 1. Oil tank;

[0046] 2. Oil guide hole;

[0047] 3. Glue storage tank;

[0048] 4. The outer edge of the ring;

[0049] 5. Gluing area;

[0050] 6. Blank area;

[0051] 7. Locate the gap. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0053] Example 1

[0054] like Figure 1As shown, this embodiment provides a steel sleeve, the circumference of the steel sleeve is provided with an oil guide structure, the circumferential outer surface of the steel sleeve is provided with a 360° annularly distributed glue containing groove 3, with the glue containing groove 3 as the boundary, the circumferential outer surface of the steel sleeve is divided by the glue containing groove 3 into a first area 5, 6 on the top and a second area on the bottom;

[0055] The oil guide structure is located in the second area;

[0056] The first area 5 , 6 includes a rubber-coated area 5 and a blank area 6 , and there is no rubber-coated area 5 above the oil guide structure.

[0057] In this embodiment, by applying glue on the glue coating area 5 on the outer circumferential surface of the steel sleeve, and press-fitting the glue and the steel sleeve into the bearing hole of the end cover together, the connection force between the steel sleeve and the end cover can be effectively improved under the adhesion effect of the glue itself, the stability of the steel sleeve in the end cover can be maintained, and the maximum push-out force during the push-out force test can be improved;

[0058] In this embodiment, the outer circumferential surface of the steel sleeve is divided by the glue containing groove 3 to form the first area 5, 6 on the top and the second area on the bottom, and the oil guide structure is in the second area on the bottom, and the glue only exists in the glue coating area 5 of the first area 5, 6. The advantage of this is that the glue and the oil guide structure are separated by the glue containing groove 3 as the boundary, and the glue is prevented from flowing into the oil guide structure, causing the oil guide structure to be blocked by the solidified glue, and the lubricating liquid cannot smoothly enter the interior through the oil guide structure to achieve lubrication. In addition, the glue containing groove 3 also has a storage function for the glue, which to a certain extent reduces the requirements for the glue application action and the amount of glue brushing. Even if the amount of glue applied is increased, the excess glue can be stored in the glue containing groove 3, and will not flow into the second area, causing a safety hazard of clogging the oil guide structure;

[0059] In this embodiment, in addition to the glue coating area 5, a blank area 6 is additionally provided in the first area 5, 6. The blank area 6 is located directly above the oil guide structure and can cover the oil guide structure in the circumferential direction. This is to prevent the glue from accidentally draining down and blocking the oil guide structure by reserving a blank position. If the first area 5, 6 directly above the oil guide structure is also coated with glue, when the coating action is wrong and the amount of glue is abnormally excessive and exceeds the volume of the glue containing groove 3, the glue will drain down under the action of gravity and directly enter the oil guide structure.

[0060] Example 2

[0061] like Figure 1 , 2 As shown in , 3 and 5, this embodiment provides a steel sleeve, which is different from the embodiment 1 in that the oil guide structure includes an oil guide hole 2 penetrating the steel sleeve.

[0062] In this embodiment, the structure of the oil guide hole 2 provides a channel for the lubricating oil to flow from outside to inside;

[0063] In some optional examples, in order to improve the oil guiding effect of the surface lubricating oil, an oil groove 1 connected to the oil guide hole 2 can be set on the outer circumferential surface of the steel sleeve, so as to guide a larger area of ​​lubricating oil into the oil guide hole 2 in a directionally manner.

[0064] Example 3

[0065] like Figure 1 , 3 As shown, this embodiment provides a steel sleeve, which is different from Embodiment 1 in that an annular outer edge 4 for determining the press-fitting depth is provided at the upper end of the steel sleeve, and the annular outer edge 4 is located at the end where the first areas 5, 6 are located.

[0066] In this embodiment, the annular outer edge 4 plays a role of press-fitting limit, and the position is limited by a mechanical structure.

[0067] Example 4

[0068] like Figure 2 , 3 As shown, this embodiment provides a steel sleeve, which is different from Embodiment 1 in that the lower port of the steel sleeve is provided with an annular inner edge, the annular inner edge is located at the end where the oil guide structure is located, and the annular inner edge is provided with a plurality of positioning notches 7.

[0069] In this embodiment, the inner edge of the annular ring can be used to determine the installation depth of the bearing, and the positioning notch 7 on the inner edge of the annular ring can, on the one hand, provide an interface for connecting with the stacking device when the steel sleeves are stacked, and on the other hand, can provide an interface for the connection between the steel sleeve and the power source when the steel sleeve needs to be rotated for coating. The positioning notch 7 can realize the transmission of rotational power through snap-on connection.

[0070] Example 5

[0071] This embodiment provides a press-fitting process, comprising the following steps:

[0072] S1. Apply glue to the glue-coating area 5 in the first area 5, 6 divided by the glue-containing groove 3. When applying glue to the glue-coating area 5, the glue brush adhering the glue remains stationary, and the steel sleeve is driven by the motor to rotate at a set angle relative to the glue brush to achieve the application action. When applying glue, a CCD visual camera is used to take a picture of the outer circumferential surface of the steel sleeve, and the distribution range of the glue in the image is analyzed to determine whether it is qualified;

[0073] S2. The object pressed into the steel sleeve is heated by an electric heating tube for 70 to 90 seconds to 150°C. The heating temperature is detected by an infrared thermometer and the heating temperature of the electric heating tube is controlled by a temperature controller;

[0074] S3. Press the steel sleeve at a speed of 50 mm / s and a force between 25000 N and 41000 N;

[0075] S4. After being pressed into place, the steel sleeve and the object pressed into the steel sleeve are cooled by blowing gas, and the temperature needs to be cooled to below 60°C.

[0076] Comparative Example 1

[0077] This comparative example provides a press-fitting process, comprising the following steps:

[0078] S1. Heating the object pressed into the steel sleeve;

[0079] S2. Press-fit the steel sleeve;

[0080] S3. After being pressed into place, it is cooled.

[0081] Push-out force test

[0082] The press-fitted products obtained in Example 5 and Comparative Example 1 were subjected to a push-out force test;

[0083] The selected push-out force providing equipment is a microcomputer-controlled electronic universal testing machine with a maximum output force of 300KN;

[0084] The maximum push-out force of the press-fit product in comparative example 1 is 18KN;

[0085] The maximum push-out force of the press-fit product in Example 5 is 71.4 KN;

[0086] It can be seen that by using the press-fitting process provided by the present invention to press-fit the steel sleeve, compared with the conventional hot assembly method, the maximum push-out force of the steel sleeve is increased to 3.96 times, meeting the requirements of the push-out force test, which greatly increases the stability of the steel sleeve installation, ensures the reliability of the steel sleeve under extreme loads, and provides protection for the safe operation of new energy electric vehicles.

[0087] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A steel sleeve, wherein the circumference of the steel sleeve is provided with an oil guide structure, characterized in that: The circumferential outer surface of the steel sleeve is provided with a 360° annularly distributed glue containing grooves (3), with the glue containing grooves (3) as the boundary, the circumferential outer surface of the steel sleeve is divided by the glue containing grooves (3) into a first area (5, 6) at the top and a second area at the bottom; The oil guiding structure is located in the second area; The first area (5, 6) comprises a glue-coated area (5) and a blank area (6), and there is no glue-coated area (5) above the oil-conducting structure.

2. A steel sleeve according to claim 1, characterized in that: The oil guide structure comprises an oil guide hole (2) penetrating the steel sleeve.

3. A steel sleeve according to claim 2, characterized in that: The oil guide structure also includes an oil groove (1) located on the outer circumferential surface of the steel sleeve, and the oil groove (1) is connected to the oil guide hole (2).

4. A steel sleeve according to claim 1, characterized in that: The upper end of the steel sleeve is provided with an annular outer edge (4) for determining the press-fitting depth, and the annular outer edge (4) is located at the end where the first area (5, 6) is located.

5. A steel sleeve according to claim 1, characterized in that: The lower end of the steel sleeve is provided with an annular inner edge, the annular inner edge is located at the end where the oil guide structure is located, and the annular inner edge is provided with a plurality of positioning notches (7).

6. A press-fitting process for press-fitting a steel sleeve as claimed in any one of claims 1 to 5, characterized in that: The following steps are included: S1. Apply glue to the glue coating area (5) in the first area (5, 6) divided by the glue containing groove (3); S2. Heating the object pressed into the steel sleeve; S3. Press-fit the steel sleeve; S4. After being pressed into place, it is cooled.

7. A press-fitting process according to claim 6, characterized in that: When the glue is applied to the glue application area (5), the glue brush adhering to the glue remains stationary, and the steel sleeve is driven by the motor to rotate at a set angle relative to the glue brush to achieve the application action.

8. A press-fitting process according to claim 6, characterized in that: When applying the glue, a CCD visual camera is used to take a picture of the outer circumferential surface of the steel sleeve, and the distribution range of the glue in the image is analyzed to see whether it is qualified.

9. A press-fitting process according to claim 6, characterized in that: The object pressed into the steel sleeve is heated in the form of an electric heating tube to a temperature range of 130 to 150°C. An infrared thermometer is used to detect the heating temperature, and a temperature controller is used to control the heating temperature of the electric heating tube.

10. A press-fitting process according to claim 6, characterized in that: The steel sleeve and the object pressed into the steel sleeve are cooled by blowing gas, and the temperature needs to be cooled to below 60°C.

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