Liquid nitrogen press-fitting equipment and press-fitting process for rear axle assembly

Abstract

The present invention discloses a liquid nitrogen press-fitting device for a rear axle assembly and a press-fitting process thereof, and belongs to the technical field of liquid nitrogen press-fitting of a rear axle assembly. The liquid nitrogen press-fitting device for a rear axle assembly comprises a box body, a cooling assembly for cooling a sleeve is installed on the box body, a rotating assembly for driving the sleeve to rotate in a direction of 180 degrees is installed on the box body, sleeve support assemblies for supporting the sleeve are installed at the front and rear ends of the left and right sides of the rotating assembly, and two groups of extrusion assemblies for pushing the sleeves on the two groups of sleeve support assemblies at the front end to move toward the bridge shell cover for press-fitting are installed on the box body. In the above manner, the present invention adopts liquid nitrogen as the cooling medium of the press-fitting process, first cools the sleeve with liquid nitrogen, and then press-fits the cooled sleeve on both sides of the bridge shell cover, and no problems such as cracking and crushing of the workpiece surface will occur during the press-fitting process, thereby improving the press-fitting quality of the rear axle assembly and reducing the rework cost.

Description

Technical Field

[0001] The invention relates to the technical field of liquid nitrogen press-fitting of a rear axle assembly, and in particular to liquid nitrogen press-fitting equipment and a press-fitting process thereof for a rear axle assembly. Background Art

[0002] The traditional rear axle assembly press-fitting process is prone to problems such as cracking and damage to the workpiece surface during the press-fitting process, which affects the press-fitting quality of the rear axle assembly and increases the rework cost.

[0003] Liquid nitrogen is a byproduct of the oxygen production industry and has a wide range of sources. Liquid nitrogen cooling is the use of liquid nitrogen for low-temperature processing, that is, using liquid nitrogen to keep the workpiece in a low-temperature cooling state. How to better apply liquid nitrogen cooling to the rear axle assembly press-fitting process is a problem that needs to be solved in this field.

[0004] Based on this, the present invention designs a liquid nitrogen press-fitting device for a rear axle assembly and a press-fitting process thereof to solve the above-mentioned problem. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a liquid nitrogen press-fitting device for a rear axle assembly and a press-fitting process thereof.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A liquid nitrogen press-fitting device for a rear axle assembly, comprising a box body, a cooling assembly for cooling a sleeve installed on the box body, a rotating assembly for driving the sleeve to rotate 180 degrees installed on the box body, sleeve supporting assemblies for supporting the sleeve installed at the front and rear ends of the left and right sides of the rotating assembly, two groups of extrusion assemblies for pushing the sleeves on the two groups of sleeve supporting assemblies at the front end to move toward the axle housing cover for press-fitting are installed on the box body, and the two groups of extrusion assemblies are respectively located on one side of the two groups of sleeve supporting assemblies at the front end;

[0008] The cooling assembly includes a second cylinder, a support frame, a connecting transverse plate, a liquid inlet pipe, a third cylinder, a first straight plate, an outer cover, a connecting slide pipe, a second straight plate, a transverse sleeve and a straight sleeve; the two ends of the support frame are respectively fixedly connected to the box body, the second cylinder is fixedly installed on the support frame, the output end of the second cylinder is fixedly connected to the connecting transverse plate, and the bottom of the connecting transverse plate is fixedly connected to the straight sleeve; one end of the liquid inlet pipe is connected to an external liquid nitrogen bottle, and the other end of the liquid inlet pipe passes through the support frame and the connecting transverse plate in sequence, and the outer wall of the end of the other end of the liquid inlet pipe is fitted and slidably connected with the inner wall of the straight sleeve; the straight sleeve The bottom is fixedly connected to the upper end of the horizontal sleeve, and the upper end of the horizontal sleeve is fixedly connected to two second straight plates, which are respectively located on both sides of the straight sleeve, and the ends of the two second straight plates away from the straight sleeve are fixedly connected to the third cylinder, and the output ends of the third cylinder are fixedly connected to the first straight plate, and the lower end of the first straight plate is fixedly connected to an outer cover for covering one end of the sleeve; the positions of the two outer covers correspond to the positions of the left and right sleeves; the ends of the outer covers close to the horizontal sleeve are fixedly connected to a connecting slide pipe, and the two connecting slide pipes are respectively slidably connected to the inside of the two ends of the horizontal sleeve.

[0009] Furthermore, the outer walls of the two connecting sliding pipes are respectively fitted and slidably connected with the inner walls at both ends of the transverse sleeve.

[0010] Furthermore, a sealing ring is fixedly connected to the inner wall of the outer cover, one end of the sealing ring is in close contact with the end of the sleeve, and a liquid outlet pipe is fixedly connected to the lower end of the outer cover, and a solenoid valve for controlling the opening and closing of the liquid outlet pipe is installed on the liquid outlet pipe.

[0011] Furthermore, two sewage pipes are fixedly connected to the inner top of the box body, and the two sewage pipes are respectively located below the two liquid outlet pipes.

[0012] Furthermore, the box body is provided with a second straight hole for cooperating with the liquid outlet pipe to move left and right, and the rotating assembly is provided with a first straight hole for cooperating with the liquid outlet pipe to move left and right.

[0013] Furthermore, the rotating assembly includes a bridge housing cover support frame, a driving shaft, a bridge housing cover mounting hole positioning rod, a driving motor, a first bevel gear and a second bevel gear; the lower end of the bridge housing cover support frame is fixedly connected to the driving shaft, the driving shaft is fixedly connected to the second bevel gear, the second bevel gear is meshingly connected to the first bevel gear, the first bevel gear is fixedly connected to the output end of the driving motor, the driving motor is fixedly connected to the inner bottom of the casing, and the lower end of the driving shaft is rotatably connected to the inner bottom of the casing; the front and rear parts of the upper end of the bridge housing cover support frame are fixedly connected to the bridge housing cover mounting hole positioning rod for installing the bridge housing cover; the bridge housing cover support frame is provided with a first straight hole for cooperating with the liquid outlet pipe to move left and right.

[0014] Furthermore, the sleeve support assembly includes an arc-shaped support seat, an L-shaped plate, a cross bar, a spring, a connecting plate, a sealing plate and a cover plate; a plurality of arc-shaped support seats for supporting and embedding the sleeve are fixedly connected to the L-shaped plate, a transverse cross bar is slidably connected to the L-shaped plate, an end of the cross bar away from the sleeve is fixedly connected to the connecting plate, the other end of the cross bar is fixedly connected to the cover plate, an end of the cover plate close to the sleeve is fixedly connected to the sealing plate for sealing the other end of the sleeve, a spring is also installed on the cross bar, one end of the spring is fixedly connected to the cover plate, and the other end of the spring is fixedly connected to the L-shaped plate.

[0015] Furthermore, the L-shaped plate is fixedly connected to the bridge housing cover support frame.

[0016] Furthermore, the extrusion assembly includes a mounting frame, a first cylinder and a push plate; the mounting frame is fixedly connected to the box body, the first cylinder is fixedly mounted on the mounting frame, the output end of the first cylinder is arranged toward the sleeve support assembly, the output end of the first cylinder is fixedly connected to the push plate, the push plate is located on one side of the connecting plate, and the positions of the push plate and the connecting plate correspond to each other on the left and right.

[0017] The present invention also provides a press-fitting process of a rear axle assembly liquid nitrogen press-fitting device, using the rear axle assembly liquid nitrogen press-fitting device, comprising the following steps:

[0018] Step 1: Install the casing on the casing support assembly and seal the other end of the casing with a sealing plate;

[0019] Step 2: Use the second cylinder to drive the connecting horizontal plate to move downward to the set position, the connecting horizontal plate drives the straight sleeve to move downward, the straight sleeve drives the horizontal sleeve, the second straight plate, the connecting sliding pipe, and the outer cover to move downward, and by starting the third cylinder, the two third cylinders respectively drive the two outer covers to move along the connecting sliding pipe toward the sleeves on both sides until the outer cover is sleeved on one end of the sleeve and the spring is compressed; then open the liquid inlet pipe, and the liquid nitrogen enters the inside of the sleeve through the liquid inlet pipe, the straight sleeve, the horizontal sleeve, and the connecting sliding pipe to cool the sleeve;

[0020] Step 3: After the cooling of the sleeve is completed, close the liquid inlet pipe, open the solenoid valve, and the liquid nitrogen flows out through the liquid outlet pipe to the drain pipe, and is recovered to the external storage tank through the drain pipe; then open the third cylinder, and the two third cylinders respectively drive the two outer covers to move inward along the connecting slide pipe and separate from the sleeves on both sides, and then open the second cylinder to drive the connecting horizontal plate to move upward to the set position, the connecting horizontal plate drives the straight sleeve to move upward, the straight sleeve drives the horizontal sleeve, the second straight plate, the connecting slide pipe, and the outer cover to move upward, and the outer cover drives the liquid outlet pipe to separate from the second straight hole and the first straight hole;

[0021] Step 4: Drive the first bevel gear to rotate by the driving motor, the first bevel gear drives the second bevel gear to rotate, the second bevel gear drives the driving shaft to rotate, the driving shaft drives the bridge cover support frame to rotate 180 degrees, the bridge cover support frame drives the four sleeve support assemblies to rotate 180 degrees, so that the two sleeve support assemblies at the rear end drive the sleeves thereon to move to the front end, and then install the bottom of the bridge cover on the positioning rod of the bridge cover mounting hole at the front end;

[0022] Step 5. Start the first cylinder to extend. The first cylinder drives the connecting plate to move toward the bridge housing cover. The connecting plate drives the cross bar to push the cover plate toward the bridge housing cover. The cover plate pushes the sleeve toward the bridge housing cover until the sleeve is pressed into the mounting part of the bridge housing cover. The installation is completed.

[0023] Beneficial Effects

[0024] The present invention drives the connecting transverse plate to move downward to a set position through the second cylinder, and the connecting transverse plate drives the straight sleeve to move downward, one end of the liquid inlet pipe slides in the straight sleeve and will not be separated, and the straight sleeve drives the transverse sleeve, the second straight plate, the connecting sliding pipe, and the outer cover to move downward, and by starting the third cylinder, the two third cylinders respectively drive the two outer covers to move along the connecting sliding pipe toward the sleeves on both sides until the outer cover is sleeved on one end of the sleeve and the spring is compressed; then the liquid inlet pipe is opened, and liquid nitrogen enters into the interior of the sleeve through the liquid inlet pipe, the straight sleeve, the transverse sleeve, and the connecting sliding pipe, so that the sleeve can be cooled in advance.

[0025] The present invention adopts liquid nitrogen as the cooling medium of the press-fitting process. The sleeve is first cooled by liquid nitrogen, and then the cooled sleeve is press-fitted on both sides of the bridge housing cover. Problems such as cracking and crushing of the workpiece surface will not occur during the press-fitting process, thereby improving the press-fitting quality of the rear axle assembly and reducing the rework cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 The figure is a three-dimensional diagram of the rear axle assembly structure;

[0028] Figure 2 The main structure of the liquid nitrogen press-fitting equipment for the rear axle assembly of the present invention is shown in FIG. Figure 1 ;

[0029] Figure 3 It is a front view of the structure of a liquid nitrogen press-fitting device for a rear axle assembly of the present invention;

[0030] Figure 4 It is a left view of the structure of a liquid nitrogen press-fitting device for a rear axle assembly of the present invention;

[0031] Figure 5 The main structure of the liquid nitrogen press-fitting equipment for the rear axle assembly of the present invention is shown in FIG. Figure 2 ;

[0032] Figure 6 The main structure of the liquid nitrogen press-fitting equipment for the rear axle assembly of the present invention is shown in FIG. Figure 3 ;

[0033] Figure 7 For along Figure 3 AA direction cross-sectional view;

[0034] Figure 8 For along Figure 4 BB direction cross-sectional view;

[0035] Fig. 9 for Figure 8 Enlarged view of point C in the middle;

[0036] Fig.10 for Figure 8 Enlarged view of point D in the middle.

[0037] The numbers in the figure represent:

[0038] 1. Box body 2. Rotating assembly 21. Bridge housing cover support frame 22. Driving shaft 23. Bridge housing cover mounting hole positioning rod 24. Driving motor 25. First bevel gear 26. Second bevel gear 3. Sleeve support assembly 31. Arc support seat 32. L-shaped plate 33. Cross bar 34. Spring 35. Connecting plate 36. Blocking plate 37. Cover plate 4. Extrusion assembly 41. Mounting frame 42. First cylinder 43. Push plate 5. Cooling assembly 51. Second cylinder 52. Support frame 53. Connecting cross plate 54. Liquid inlet pipe 55. Third cylinder 56. First straight plate 57. Outer cover 58. Connecting slide pipe 59. Second straight plate 510. Drain pipe 511. Cross sleeve 512. Straight sleeve 513. Liquid outlet pipe 514. Blocking ring 515. First straight hole 516. Second straight hole 517. Solenoid valve DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The present invention will be further described below in conjunction with the embodiments.

[0041] Example 1

[0042] Please refer to the instruction manual Figure 1 , 2 , 4, 5, 6, 7, 8 and 10, a liquid nitrogen press-fitting device for a rear axle assembly, comprising a box body 1, a cooling assembly 5 for cooling a sleeve installed on the box body 1, a rotating assembly 2 for driving the sleeve to rotate 180 degrees installed on the box body 1, sleeve support assemblies 3 for supporting the sleeve installed at the front and rear ends of the left and right sides of the rotating assembly 2, two groups of extrusion assemblies 4 for pushing the sleeves on the two groups of sleeve support assemblies 3 at the front end toward the bridge housing cover for press-fitting are installed on the box body 1, and the two groups of extrusion assemblies 4 are respectively located on one side of the two groups of sleeve support assemblies 3 at the front end;

[0043] The cooling assembly 5 includes a second cylinder 51, a support frame 52, a connecting horizontal plate 53, a liquid inlet pipe 54, a third cylinder 55, a first straight plate 56, an outer cover 57, a connecting slide pipe 58, a second straight plate 59, a drain pipe 510, a horizontal sleeve 511, a straight sleeve 512, a liquid outlet pipe 513, a blocking ring 514 and a solenoid valve 517;

[0044] The two ends of the support frame 52 are respectively fixedly connected to the box body 1, the second cylinder 51 is fixedly installed on the support frame 52, the output end of the second cylinder 51 is fixedly connected to the connecting horizontal plate 53, and the bottom of the connecting horizontal plate 53 is fixedly connected to the straight sleeve 512; one end of the liquid inlet pipe 54 is connected to the external liquid nitrogen bottle, and the other end of the liquid inlet pipe 54 passes through the support frame 52 and the connecting horizontal plate 53 in sequence, and the outer wall of the end of the other end of the liquid inlet pipe 54 is fitted and slidably connected with the inner wall of the straight sleeve 512; the bottom of the straight sleeve 512 is fixedly connected to the upper end of the horizontal sleeve 511, and the upper end of the horizontal sleeve 511 is fixedly connected to two second straight plates 59, and the two second straight plates 59 They are respectively located on both sides of the straight sleeve 512. The ends of the two second straight plates 59 away from the straight sleeve 512 are fixedly connected to the third cylinder 55. The output ends of the third cylinder 55 are fixedly connected to the first straight plate 56. The lower ends of the first straight plate 56 are fixedly connected to the outer cover 57 used to cover one end of the sleeve. The positions of the two outer covers 57 correspond to the positions of the left and right sleeves. The ends of the outer covers 57 close to the transverse sleeve 511 are fixedly connected to the connecting slide pipes 58. The two connecting slide pipes 58 are respectively slidably connected to the inside of the two ends of the transverse sleeve 511. The outer walls of the two connecting slide pipes 58 are respectively fitted and slidably connected to the inner walls of the two ends of the transverse sleeve 511.

[0045] The second cylinder 51 drives the connecting transverse plate 53 to move downward to the set position, and the connecting transverse plate 53 drives the straight sleeve 512 to move downward, and one end of the liquid inlet pipe 54 slides in the straight sleeve 512 and will not fall off, and the straight sleeve 512 drives the transverse sleeve 511, the second straight plate 59, the connecting slide pipe 58, and the outer cover 57 to move downward, and by starting the third cylinder 55, the two third cylinders 55 respectively drive the two outer covers 57 to move along the connecting slide pipe 58 toward the sleeves on both sides until the outer covers 57 are sleeved on one end of the sleeve and the sleeve is pressed; then the liquid inlet pipe 54 is opened, and liquid nitrogen enters the interior of the sleeve through the liquid inlet pipe 54, the straight sleeve 512, the transverse sleeve 511, and the connecting slide pipe 58 to cool the sleeve;

[0046] A plugging ring 514 is fixedly connected to the inner wall of the outer cover 57, one end of the plugging ring 514 is in contact with the end of the sleeve, a liquid outlet pipe 513 is fixedly connected to the lower end of the outer cover 57, and a solenoid valve 517 for controlling the opening and closing of the liquid outlet pipe 513 is installed on the liquid outlet pipe 513, a second straight hole 516 for cooperating with the left and right movement of the liquid outlet pipe 513 is opened on the box body 1, and a first straight hole 515 for cooperating with the left and right movement of the liquid outlet pipe 513 is opened on the rotating component 2, and two sewage pipes 510 are fixedly connected to the inner top of the box body 1, and the two sewage pipes 510 are respectively located below the two liquid outlet pipes 513;

[0047] The inner wall of one end of the outer cover 57 is closely connected to the outer wall of the sleeve, and the lower part of the other end of the outer cover 57 is connected to the liquid outlet pipe 513;

[0048] When the outer cover 57 moves downward, the liquid outlet pipe 513 is driven to move downward to the second straight hole 516 and the first straight hole 515. When the third cylinder 55 drives the outer cover 57 to move along the connecting slide pipe 58 toward the sleeves on both sides, the liquid outlet pipe 513 moves along the second straight hole 516 and the first straight hole 515. The second straight hole 516 and the first straight hole 515 are preferably strip-shaped. After the sleeve is cooled, the liquid inlet pipe 54 is closed, the solenoid valve 517 is opened, and the liquid nitrogen flows out through the liquid outlet pipe 513 to the drain pipe 510. Recover to the external storage tank; then start the third cylinder 55, the two third cylinders 55 respectively drive the two outer covers 57 to move inward along the connecting slide 58 and separate from the sleeves on both sides, and then start the second cylinder 51 to drive the connecting transverse plate 53 to move upward to the set position, the connecting transverse plate 53 drives the straight sleeve 512 to move upward, the straight sleeve 512 drives the transverse sleeve 511, the second straight plate 59, the connecting slide 58, and the outer cover 57 to move upward, and the outer cover 57 drives the liquid outlet pipe 513 to separate from the second straight hole 516 and the first straight hole 515.

[0049] The present invention adopts liquid nitrogen as the cooling medium of the press-fitting process, first cools the sleeve with liquid nitrogen, and then press-fits the cooled sleeve on both sides of the bridge housing cover, thereby avoiding the phenomena of cracking and crushing of the workpiece surface during direct press-fitting in the traditional process. The present invention will not cause problems such as cracking and crushing of the workpiece surface during the press-fitting process, thereby improving the press-fitting quality of the rear axle assembly and reducing the rework cost.

[0050] Example 2

[0051] Please refer to the instruction manual Figure 2-9 On the basis of Example 1, the rotating assembly 2 includes a bridge housing cover support frame 21, a drive shaft 22, a bridge housing cover mounting hole positioning rod 23, a drive motor 24, a first bevel gear 25 and a second bevel gear 26; the bridge housing cover support frame 21 is located above the housing 1, and the lower end of the bridge housing cover support frame 21 is fixedly connected to the drive shaft 22, and the drive shaft 22 is fixedly connected to the second bevel gear 26, the second bevel gear 26 is meshed with the first bevel gear 25, the first bevel gear 25 is fixedly connected to the output end of the drive motor 24, the drive motor 24 is fixedly connected to the inner bottom of the housing 1, and the lower end of the drive shaft 22 is rotatably connected to the inner bottom of the housing 1; the front and rear parts of the upper end of the bridge housing cover support frame 21 are fixedly connected to the bridge housing cover mounting hole positioning rod 23 for installing the bridge housing cover; the bridge housing cover support frame 21 is provided with a first straight hole 515 that cooperates with the liquid outlet pipe 513 to move left and right;

[0052] The first bevel gear 25 is driven to rotate by the driving motor 24, the first bevel gear 25 drives the second bevel gear 26 to rotate, the second bevel gear 26 drives the driving shaft 22 to rotate, and the driving shaft 22 drives the bridge housing cover support frame 21 to rotate 180 degrees;

[0053] The casing support assembly 3 includes an arc-shaped support seat 31, an L-shaped plate 32, a cross bar 33, a spring 34, a connecting plate 35, a blocking plate 36 and a cover plate 37; the L-shaped plate 32 is fixedly connected with a plurality of arc-shaped support seats 31 for supporting and embedding the casing, the L-shaped plate 32 is slidably connected with a transverse cross bar 33, the end of the cross bar 33 away from the casing is fixedly connected with a connecting plate 35, the other end of the cross bar 33 is fixedly connected with a cover plate 37, the end of the cover plate 37 close to the casing is fixedly connected with a blocking plate 36 for blocking the other end of the casing, and a spring 34 is also installed on the cross bar 33, one end of the spring 34 is fixedly connected to the cover plate 37, and the other end of the spring 34 is fixedly connected to the L-shaped plate 32;

[0054] The L-shaped plate 32 is fixedly connected to the bridge housing cover support frame 21;

[0055] Sleeve support assemblies 3 are installed at the four corners of the rotating assembly 2. The two sleeve support assemblies 3 at the rear end are used to support and seal the sleeve during cooling; after the sleeve is cooled, the sleeve support assembly 3 is driven to rotate one hundred and eighty degrees by the rotating assembly 2, so that the two sleeve support assemblies 3 at the rear end drive the sleeve thereon to move to the front end, and then the bottom of the bridge shell cover is installed on the bridge shell cover mounting hole positioning rod 23, and the bridge shell cover is laterally limited by the bridge shell cover mounting hole positioning rod 23 to avoid displacement during press installation; then the extrusion assemblies 4 located on both sides of the front sleeve are started to press the two sleeves onto the two ends of the bridge shell cover respectively.

[0056] The extrusion assembly 4 includes a mounting frame 41, a first cylinder 42 and a push plate 43; the mounting frame 41 is fixedly connected to the box body 1, the first cylinder 42 is fixedly installed on the mounting frame 41, the output end of the first cylinder 42 is arranged toward the sleeve support assembly 3, and the output end of the first cylinder 42 is fixedly connected to the push plate 43, the push plate 43 is located on one side of the connecting plate 35, and the positions of the push plate 43 and the connecting plate 35 correspond to each other on the left and right;

[0057] After the sleeve support assembly 3 is rotated 180 degrees by the rotating assembly 2, the first cylinder 42 is started to extend, and the first cylinder 42 drives the connecting plate 35 to move toward the bridge housing cover, and the connecting plate 35 drives the cross bar 33 to push the cover plate 37 to move toward the bridge housing cover, and the cover plate 37 pushes the sleeve to move toward the bridge housing cover, and the installation parts of the sleeve and the bridge housing cover correspond to each other on the left and right, until the sleeve is pressed into the installation part of the bridge housing cover, the installation is completed. There will be no problems such as cracking and crushing of the workpiece surface during the press-fitting process.

[0058] Example 3

[0059] Please refer to the instruction manual Figure 1-10 Based on Example 2, this example discloses a press-fitting process of a liquid nitrogen press-fitting device for a rear axle assembly, and the liquid nitrogen press-fitting device for a rear axle assembly is used, and the process includes the following steps:

[0060] Step 1: Install the casing on the casing support assembly 3, and seal the other end of the casing with a sealing plate 36;

[0061] Step 2: The second cylinder 51 drives the connecting horizontal plate 53 to move downward to the set position, and the connecting horizontal plate 53 drives the straight sleeve 512 to move downward, and the straight sleeve 512 drives the horizontal sleeve 511, the second straight plate 59, the connecting slide pipe 58, and the outer cover 57 to move downward. By starting the third cylinder 55, the two third cylinders 55 respectively drive the two outer covers 57 to move along the connecting slide pipe 58 toward the sleeves on both sides until the outer cover 57 is sleeved on one end of the sleeve and the spring 34 is compressed, thereby blocking and compressing the sleeve; then the liquid inlet pipe 54 is opened, and the liquid nitrogen enters the interior of the sleeve through the liquid inlet pipe 54, the straight sleeve 512, the horizontal sleeve 511, and the connecting slide pipe 58 to cool the sleeve;

[0062] Step 3: After the cooling of the sleeve is completed, the liquid inlet pipe 54 is closed, and the solenoid valve 517 is opened, and the liquid nitrogen flows out to the drain pipe 510 through the liquid outlet pipe 513, and is recovered to the external storage tank through the drain pipe 510; then the third cylinder 55 is opened, and the two third cylinders 55 respectively drive the two outer covers 57 to move inward along the connecting slide pipe 58 to separate from the sleeves on both sides, and then the second cylinder 51 is opened to drive the connecting horizontal plate 53 to move upward to the set position, and the connecting horizontal plate 53 drives the straight sleeve 512 to move upward, and the straight sleeve 512 drives the horizontal sleeve 511, the second straight plate 59, the connecting slide pipe 58, and the outer cover 57 to move upward, and the outer cover 57 drives the liquid outlet pipe 513 to separate from the second straight hole 516 and the first straight hole 515;

[0063] Step 4: Drive the first bevel gear 25 to rotate by the driving motor 24, the first bevel gear 25 drives the second bevel gear 26 to rotate, the second bevel gear 26 drives the driving shaft 22 to rotate, the driving shaft 22 drives the bridge cover support frame 21 to rotate 180 degrees, the bridge cover support frame 21 drives the four sleeve support assemblies 3 to rotate 180 degrees, so that the two sleeve support assemblies 3 at the rear end drive the sleeves thereon to move to the front end, and then install the bottom of the bridge cover on the bridge cover installation hole positioning rod 23 at the front end;

[0064] Step 5, start the first cylinder 42 to extend, the first cylinder 42 drives the connecting plate 35 to move toward the bridge housing cover, the connecting plate 35 drives the cross bar 33 to push the cover plate 37 to move toward the bridge housing cover, the cover plate 37 pushes the sleeve to move toward the bridge housing cover until the sleeve is pressed into the installation part of the bridge housing cover, and the installation is completed.

[0065] The press-fitting process of the liquid nitrogen press-fitting equipment for the rear axle assembly of the present invention adopts liquid nitrogen as the cooling medium of the press-fitting process. The sleeve is first cooled by liquid nitrogen and then the cooled sleeve is press-fitted on both sides of the axle housing cover. Problems such as cracking and crushing of the workpiece surface will not occur during the press-fitting process, thereby improving the press-fitting quality of the rear axle assembly and reducing the rework cost.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A liquid nitrogen press-fitting device for a rear axle assembly, comprising a box (1), characterized in that: The box body (1) is provided with a cooling assembly (5) for cooling the sleeve, the box body (1) is provided with a rotating assembly (2) for driving the sleeve to rotate 180 degrees, the front and rear ends of the left and right sides of the rotating assembly (2) are both provided with sleeve supporting assemblies (3) for supporting the sleeve, the box body (1) is provided with two groups of extrusion assemblies (4) for pushing the sleeves on the two groups of sleeve supporting assemblies (3) at the front end to move toward the bridge housing cover for press-fitting, and the two groups of extrusion assemblies (4) are respectively located on one side of the two groups of sleeve supporting assemblies (3) at the front end; The cooling assembly (5) comprises a second cylinder (51), a support frame (52), a connecting transverse plate (53), a liquid inlet pipe (54), a third cylinder (55), a first straight plate (56), an outer cover (57), a connecting slide pipe (58), a second straight plate (59), a transverse sleeve (511) and a straight sleeve (512); the two ends of the support frame (52) are respectively fixedly connected to the box body (1), the second cylinder (51) is fixedly installed on the support frame (52), the output end of the second cylinder (51) is fixedly connected to the connecting transverse plate (53), and the bottom of the connecting transverse plate (53) is fixedly connected to the straight sleeve (512); one end of the liquid inlet pipe (54) is connected to an external liquid nitrogen bottle, and the other end of the liquid inlet pipe (54) passes through the support frame (52) and the connecting transverse plate (53) in sequence, and the end outer wall of the other end of the liquid inlet pipe (54) is connected to the straight sleeve (512). The inner wall is fitted and slidably connected; the bottom of the straight sleeve (512) is fixedly connected to the upper end of the transverse sleeve (511); the upper end of the transverse sleeve (511) is fixedly connected to two second straight plates (59); the two second straight plates (59) are respectively located on both sides of the straight sleeve (512); the ends of the two second straight plates (59) away from the straight sleeve (512) are fixedly connected to the third cylinder (55); the output ends of the third cylinder (55) are fixedly connected to the first straight plate (56); the lower ends of the first straight plate (56) are fixedly connected to an outer cover (57) for covering one end of the sleeve; the positions of the two outer covers (57) correspond to the positions of the left and right sleeves; the ends of the outer covers (57) close to the transverse sleeve (511) are fixedly connected to a connecting slide pipe (58); the two connecting slide pipes (58) are respectively slidably connected inside the two ends of the transverse sleeve (511).

2. The rear axle assembly liquid nitrogen press equipment according to claim 1, characterized in that: The outer walls of the two connecting sliding pipes (58) are respectively fitted and slidably connected with the inner walls at both ends of the transverse sleeve (511).

3. The rear axle assembly liquid nitrogen press-fitting equipment according to claim 1, characterized in that: A blocking ring (514) is fixedly connected to the inner wall of the outer cover (57), one end of the blocking ring (514) is in close contact with the end of the sleeve, and a liquid outlet pipe (513) is fixedly connected to the lower end of the outer cover (57), and a solenoid valve (517) for controlling the opening and closing of the liquid outlet pipe (513) is installed on the liquid outlet pipe (513).

4. The rear axle assembly liquid nitrogen press-fitting equipment according to claim 3, characterized in that: Two sewage discharge pipes (510) are fixedly connected to the inner top of the box body (1), and the two sewage discharge pipes (510) are respectively located below the two liquid outlet pipes (513).

5. The rear axle assembly liquid nitrogen press-fitting equipment according to claim 4, characterized in that: The box body (1) is provided with a second straight hole (516) for cooperating with the liquid outlet pipe (513) to move left and right, and the rotating component (2) is provided with a first straight hole (515) for cooperating with the liquid outlet pipe (513) to move left and right.

6. The rear axle assembly liquid nitrogen press-fitting equipment according to claim 5, characterized in that: The rotating assembly (2) comprises a bridge housing cover support frame (21), a drive shaft (22), a bridge housing cover mounting hole positioning rod (23), a drive motor (24), a first bevel gear (25) and a second bevel gear (26); the lower end of the bridge housing cover support frame (21) is fixedly connected to the drive shaft (22), the drive shaft (22) is fixedly connected to the second bevel gear (26), the second bevel gear (26) is meshingly connected to the first bevel gear (25), the first bevel gear (25) is fixedly connected to the output end of the drive motor (24), the drive motor (24) is fixedly connected to the inner bottom of the housing (1), and the lower end of the drive shaft (22) is rotatably connected to the inner bottom of the housing (1); the front and rear parts of the upper end of the bridge housing cover support frame (21) are fixedly connected to the bridge housing cover mounting hole positioning rod (23) for mounting the bridge housing cover; the bridge housing cover support frame (21) is provided with a first straight hole (515) for cooperating with the liquid outlet pipe (513) to move left and right.

7. The rear axle assembly liquid nitrogen press-fitting equipment according to claim 6, characterized in that: The sleeve support assembly (3) comprises an arc-shaped support seat (31), an L-shaped plate (32), a cross bar (33), a spring (34), a connecting plate (35), a blocking plate (36) and a cover plate (37); the L-shaped plate (32) is fixedly connected with a plurality of arc-shaped support seats (31) for supporting and embedding the sleeve; the L-shaped plate (32) is slidably connected with a transverse cross bar (33); the end of the cross bar (33) away from the sleeve is fixedly connected with the connecting plate (35); the other end of the cross bar (33) is fixedly connected with the cover plate (37); the end of the cover plate (37) close to the sleeve is fixedly connected with the blocking plate (36) for blocking the other end of the sleeve; a spring (34) is also installed on the cross bar (33); one end of the spring (34) is fixedly connected with the cover plate (37); and the other end of the spring (34) is fixedly connected with the L-shaped plate (32).

8. The rear axle assembly liquid nitrogen press-fitting equipment according to claim 7, characterized in that: The L-shaped plate (32) is fixedly connected to the bridge housing cover support frame (21).

9. The rear axle assembly liquid nitrogen press-fitting equipment according to claim 7, characterized in that: The extrusion assembly (4) comprises a mounting frame (41), a first cylinder (42) and a push plate (43); the mounting frame (41) is fixedly connected to the box body (1); the first cylinder (42) is fixedly mounted on the mounting frame (41); the output end of the first cylinder (42) is arranged toward the sleeve support assembly (3); the output end of the first cylinder (42) is fixedly connected to the push plate (43); the push plate (43) is located on one side of the connecting plate (35); and the positions of the push plate (43) and the connecting plate (35) correspond to each other on the left and right.

10. A press-fitting process of a rear axle assembly liquid nitrogen press-fitting equipment, characterized in that: The liquid nitrogen press-fitting equipment for the rear axle assembly according to claim 9 comprises the following steps: Step 1: Install the casing on the casing support assembly (3), and seal the other end of the casing with a sealing plate (36); Step 2: The connecting transverse plate (53) is driven to move downward to a set position by the second cylinder (51), and the connecting transverse plate (53) drives the straight sleeve (512) to move downward, and the straight sleeve (512) drives the transverse sleeve (511), the second straight plate (59), the connecting slide pipe (58), and the outer cover (57) to move downward. By starting the third cylinder (55), the two third cylinders (55) respectively drive the two outer covers (57) to move along the connecting slide pipe (58) toward the sleeves on both sides until the outer covers (57) are sleeved on one end of the sleeve and the spring (34) is compressed; then the liquid inlet pipe (54) is opened, and liquid nitrogen enters the interior of the sleeve through the liquid inlet pipe (54), the straight sleeve (512), the transverse sleeve (511), and the connecting slide pipe (58) to cool the sleeve; Step 3: After the cooling of the sleeve is completed, close the liquid inlet pipe (54), open the solenoid valve (517), and the liquid nitrogen flows out to the drain pipe (510) through the liquid outlet pipe (513), and is recovered to the external storage tank through the drain pipe (510); then open the third cylinder (55), and the two third cylinders (55) respectively drive the two outer covers (57) to move inward along the connecting slide pipe (58) to separate from the sleeves on both sides, and then open the second cylinder (51) to drive the connecting horizontal plate (53) to move upward to the set position, and the connecting horizontal plate (53) drives the straight sleeve (512) to move upward, and the straight sleeve (512) drives the horizontal sleeve (511), the second straight plate (59), the connecting slide pipe (58), and the outer cover (57) to move upward, and the outer cover (57) drives the liquid outlet pipe (513) to separate from the second straight hole (516) and the first straight hole (515); Step 4: Drive the first bevel gear (25) to rotate by the driving motor (24), the first bevel gear (25) drives the second bevel gear (26) to rotate, the second bevel gear (26) drives the driving shaft (22) to rotate, the driving shaft (22) drives the bridge cover support frame (21) to rotate 180 degrees, the bridge cover support frame (21) drives the four sleeve support assemblies (3) to rotate 180 degrees, so that the two sleeve support assemblies (3) at the rear end drive the sleeves thereon to move to the front end, and then install the bottom of the bridge cover on the bridge cover installation hole positioning rod (23) at the front end; Step 5: Start the first cylinder (42) and extend it. The first cylinder (42) drives the connecting plate (35) to move toward the bridge housing cover. The connecting plate (35) drives the cross bar (33) to push the cover plate (37) to move toward the bridge housing cover. The cover plate (37) pushes the sleeve to move toward the bridge housing cover until the sleeve is pressed into the installation portion of the bridge housing cover. The installation is completed.

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