Three-cylinder engine cylinder block assembly production line and assembly method thereof

Abstract

The present application relates to a three-cylinder engine block assembly production line and an assembly method thereof, belonging to the technical field of engine production equipment. It comprises: an engine transmission line, which includes an engine tray for carrying the engine block and a conveyor line for conveying the engine tray to the assembly station; a lifting and positioning mechanism, which is located below the engine tray and is used to lift the piston and connecting rod upward so that the piston and connecting rod move toward the direction close to the crankshaft; a crankshaft rotation mechanism, which is located at one end of the engine tray and is used to rotate the crankshaft so that the big end of the connecting rod fits the connecting rod journal of the crankshaft; a bolt tightening unit, which is located above the engine tray and is used to tighten the connecting rod cover to the connecting rod by tightening the bolts. The three-cylinder engine block assembly production line of the present application can realize single-person assembly operation or unmanned automatic assembly operation, greatly improving the assembly efficiency of the three-cylinder engine block and reducing production costs.

Description

Technical Field

[0001] The present application relates to the technical field of engine production equipment, and in particular to a three-cylinder engine cylinder block assembly production line and an assembly method thereof. Background Art

[0002] The crankshaft connecting rod journal of a three-cylinder engine has a 120-degree symmetrical structure, which means that the piston connecting rod assembly cannot be assembled in one go. The usual assembly method is as follows:

[0003] On the workbench, the worker first fastens the crankshaft and mainshaft cover to the engine block by tightening the bolts;

[0004] Manually install the piston-connecting rod assembly in the first cylinder bore and flip the engine block so that the bottom faces upwards;

[0005] Manually rotate the crankshaft so that the connecting rod journal of the crankshaft fits into the big end of the connecting rod in the first cylinder bore;

[0006] Manually pre-install the connecting rod cap on the big end of the connecting rod in the first cylinder hole, tighten the bolts to fix the connecting rod cap on the connecting rod, and then turn the engine block over to a flat position;

[0007] Manually install the piston-connecting rod assembly in the third cylinder hole and flip the engine block so that the bottom is facing upwards;

[0008] Manually rotate the crankshaft so that the connecting rod journal of the crankshaft fits into the big end of the connecting rod in the third cylinder bore;

[0009] Manually pre-install the connecting rod cap on the big end of the connecting rod in the third cylinder hole, tighten the bolts to fix the connecting rod cap on the connecting rod, and then turn the engine block over to a flat position;

[0010] Manually install the piston-connecting rod assembly in the second cylinder bore and flip the engine block over so that the bottom faces upwards;

[0011] Manually rotate the crankshaft so that the connecting rod journal of the crankshaft fits into the big end of the connecting rod in the second cylinder bore;

[0012] Manually pre-install the connecting rod cover on the big end of the connecting rod in the second cylinder hole, tighten the bolts to fix the connecting rod cover on the connecting rod, and complete the assembly of the piston and connecting rod group of the engine cylinder block.

[0013] Due to the assembly cycle limitations of the three-cylinder engine block, the piston-connecting rod assembly cannot be completed by a single device at the same workstation, resulting in a long process flow or the need for two workers to cooperate to complete the assembly of the piston-connecting rod assembly. This results in a low degree of assembly automation, low assembly efficiency, and high costs. Summary of the Invention

[0014] An embodiment of the present application provides a three-cylinder engine block assembly production line and an assembly method thereof to solve the problems in related technologies such as a long three-cylinder engine block assembly process or the need for two workers to cooperate to complete the piston-connecting rod assembly, a low degree of assembly automation, low assembly efficiency, and high cost.

[0015] A first aspect of an embodiment of the present application provides a three-cylinder engine block assembly production line, comprising:

[0016] An engine transmission line, the engine transmission line comprising an engine tray for carrying an engine block and a conveyor line for conveying the engine tray to an assembly station;

[0017] A lifting and positioning mechanism, located below the engine tray, for lifting the piston and the connecting rod upward so as to move the piston and the connecting rod toward the crankshaft;

[0018] a crankshaft rotating mechanism, the crankshaft rotating mechanism being located at one end of the engine tray and being used to rotate the crankshaft so that the big end of the connecting rod fits into the connecting rod journal of the crankshaft;

[0019] A bolt tightening unit is located above the engine tray and is used to fasten the connecting rod cover to the connecting rod by tightening bolts.

[0020] In some embodiments: the lifting and positioning mechanism includes a base, on which a first lifting mechanism, a second lifting mechanism and a third lifting mechanism are arranged in sequence. The first lifting mechanism, the second lifting mechanism and the third lifting mechanism all pass through the engine tray through lifting and lowering movements, and correspond one-to-one to the positions of the three cylinder holes of the engine block.

[0021] In some embodiments: the crankshaft rotation mechanism includes a bracket, and a rotating assembly located on the bracket for connecting to one end of the crankshaft and driving the crankshaft to rotate to a set angle;

[0022] The bracket is provided with an obstacle avoidance mechanism for driving the rotating assembly to move close to or away from the engine cylinder body, so that the conveyor line conveys the engine cylinder body to the assembly station.

[0023] In some embodiments: the obstacle avoidance mechanism includes a rotating swing arm, one end of which is rotatably connected to the bracket via a rotating shaft, and the other end of which is connected to the rotating assembly;

[0024] The rotating assembly includes a crankshaft shifter rotatably connected to the rotating swing arm, and the crankshaft shifter is connected to a handwheel or a motor that drives the crankshaft shifter to rotate.

[0025] In some embodiments: the bolt tightening unit includes a frame, a tightening pitch-changing mechanism is fixedly provided on the top of the frame, and a bolt tightening mechanism for tightening bolts is slidably connected to the tightening pitch-changing mechanism;

[0026] The tightening pitch-changing mechanism drives the bolt tightening mechanism to move along the length direction of the engine cylinder body, so that the bolt tightening mechanism is aligned with the three connecting rod covers in the engine cylinder body in sequence.

[0027] In some embodiments: an angle adjustment mechanism for adjusting the pitch angle of the bolt tightening mechanism is provided between the tightening pitch changing mechanism and the bolt tightening mechanism;

[0028] The tightening and pitch-changing mechanism includes a first guide rail mounting plate and a first slider mounting plate, wherein the first guide rail mounting plate and the first slider mounting plate are connected via a horizontal guide rail and a slider;

[0029] The angle adjustment mechanism includes a first hinge seat fixedly connected to the first slider mounting plate, and a second hinge seat fixedly connected to the bolt tightening mechanism;

[0030] The first hinge seat and the second hinge seat are rotatably connected via a hinge shaft, and the bolt tightening mechanism is further provided with an angle locking plate fixedly connected to the first slider mounting plate.

[0031] In some embodiments: the tightening and pitch-changing mechanism further includes a telescopic cylinder fixed to the first guide rail mounting plate for driving the bolt tightening mechanism to move along the length direction of the engine cylinder block;

[0032] The telescopic cylinder is provided with three working positions corresponding one to one to the positions of the three cylinder holes of the engine cylinder block;

[0033] When the telescopic cylinder drives the bolt tightening mechanism to a certain cylinder hole position, the lifting and positioning mechanism lifts the piston and connecting rod centered in the cylinder hole upwards.

[0034] In some embodiments: the bolt tightening mechanism includes a second guide rail mounting plate and a second slider mounting plate, and the second guide rail mounting plate and the second slider mounting plate are connected via a vertical guide rail and a slider;

[0035] The second slider mounting plate is fixedly connected to two bolt tighteners arranged in parallel, and the second guide rail mounting plate is provided with a lifter for driving the bolt tighteners to move up and down.

[0036] In some embodiments: a lifting mechanism is further provided at the bottom of the frame for driving the lifting and positioning mechanism to move up and down, the lifting mechanism includes a third guide rail mounting plate fixed on the frame, the third guide rail mounting plate is connected to a support plate via a vertical guide rail and a slider, the lifting and positioning mechanism is fixed on the top of the support plate, and a lifting cylinder is further provided on the frame for driving the support plate to move up and down.

[0037] A second aspect of the present application provides an assembly method for a three-cylinder engine block assembly production line, the method using the three-cylinder engine block assembly production line described in any one of the above embodiments, the method comprising:

[0038] Assemble the piston and connecting rod and install them into the cylinder hole of the engine block. Turn the engine block over so that the bottom is facing upwards and deflect the big end of the connecting rod towards the direction of the bolt tightening unit.

[0039] Tighten the main shaft cover bolts to secure the crankshaft and main shaft cover to the engine block, control the crankshaft rotation mechanism to return it to the working position and connect it to the end of the crankshaft;

[0040] activating the lifting and positioning mechanism to lift the piston and the connecting rod in the first cylinder bore upward, so that the piston and the connecting rod in the first cylinder bore move toward the crankshaft;

[0041] Rotating the crankshaft using a crankshaft rotating mechanism so that the big end of the connecting rod in the first cylinder bore fits into the connecting rod journal of the crankshaft;

[0042] Pre-install the connecting rod cover and bolts in the first cylinder hole, tighten the bolts using the bolt tightening unit to fasten the connecting rod cover to the connecting rod, and lower the lifting and positioning mechanism to its original position;

[0043] activating the lifting and positioning mechanism to lift the piston and the connecting rod in the third cylinder bore upward, so that the piston and the connecting rod in the third cylinder bore move toward the crankshaft;

[0044] Rotating the crankshaft using a crankshaft rotating mechanism so that the big end of the connecting rod in the third cylinder bore fits into the connecting rod journal of the crankshaft;

[0045] Pre-install the connecting rod cover and bolts in the third cylinder hole, move the bolt tightening unit to the top of the third cylinder hole, tighten the bolts to fasten the connecting rod cover to the connecting rod, and lower the lifting and positioning mechanism to its original position;

[0046] activating the lifting and positioning mechanism to lift the piston and the connecting rod in the second cylinder bore upward, so that the piston and the connecting rod in the second cylinder bore move toward the crankshaft;

[0047] Rotating the crankshaft using a crankshaft rotating mechanism so that the big end of the connecting rod in the second cylinder bore fits into the connecting rod journal of the crankshaft;

[0048] Pre-install the connecting rod cover and bolts in the second cylinder hole, move the bolt tightening unit to the top of the second cylinder hole, tighten the bolts to fasten the connecting rod cover to the connecting rod, and lower the lifting and positioning mechanism to its original position;

[0049] Control the crankshaft rotation mechanism to disengage from the end of the crankshaft and return it to its original position, start the engine transmission line, and move the assembled engine cylinder block to the next station.

[0050] The beneficial effects of the technical solution provided by this application include:

[0051] An embodiment of the present application provides a three-cylinder engine block assembly production line and an assembly method thereof. Since the three-cylinder engine block assembly production line of the present application is provided with an engine transmission line, it includes an engine tray for carrying the engine block and a conveyor line for conveying the engine tray to the assembly station; a lifting and positioning mechanism, which is located below the engine tray and is used to lift the piston and connecting rod upward so that the piston and connecting rod move toward the direction close to the crankshaft; a crankshaft rotating mechanism, which is located at one end of the engine tray and is used to rotate the crankshaft so that the big end of the connecting rod fits into the connecting rod journal of the crankshaft; a bolt tightening unit, which is located above the engine tray and is used to fasten the connecting rod cover to the connecting rod by tightening the bolts.

[0052] Therefore, the three-cylinder engine block assembly production line of the present application utilizes an engine transmission line to transport the engine block to a predetermined assembly station, thereby reducing the workload of workers and achieving streamlined assembly operations, thereby improving assembly efficiency. When connecting the piston-connecting rod assembly to the crankshaft, the piston and connecting rod are first lifted upward using a lifting and positioning mechanism to move the piston and connecting rod toward the crankshaft. The crankshaft is then rotated using a crankshaft rotation mechanism to allow the large end of the connecting rod to fit the connecting rod journal of the crankshaft. Finally, the connecting rod cap is tightened to the connecting rod by tightening the bolts using a bolt tightening unit, thereby completing the automated assembly of the piston-connecting rod assembly, crankshaft, and engine block. This three-cylinder engine block assembly production line can be used for single-person assembly operations or unmanned automatic assembly operations, greatly improving the assembly efficiency of the three-cylinder engine block and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0054] Figure 1 A structural perspective diagram of an embodiment of the present application;

[0055] Figure 2 This is a structural front view of an embodiment of the present application;

[0056] Figure 3 This is a left side view of the structure of an embodiment of the present application;

[0057] Figure 4 This is a structural stereogram of the lifting and positioning mechanism of an embodiment of the present application;

[0058] Figure 5 This is a structural front view of the lifting and positioning mechanism of an embodiment of the present application;

[0059] Figure 6 for Figure 5 Cross-sectional view along AA direction;

[0060] Figure 7 This is a structural perspective diagram of the crankshaft rotating mechanism according to an embodiment of the present application;

[0061] Figure 8 This is a structural front view of the crankshaft rotating mechanism of an embodiment of the present application;

[0062] Figure 9 This is a structural stereogram of the tightening and pitch-changing mechanism according to an embodiment of the present application;

[0063] Figure 10 This is a structural perspective diagram of a bolt tightening mechanism according to an embodiment of the present application;

[0064] Figure 11 This is a structural front view of the bolt tightening mechanism according to an embodiment of the present application;

[0065] Figure 12 This is a left side view of the structure of the bolt tightening mechanism according to an embodiment of the present application;

[0066] Figure 13 This is a structural perspective diagram of the rack according to an embodiment of the present application.

[0067] Reference numerals:

[0068] 100, engine transmission line; 110, engine tray; 120, conveyor line;

[0069] 200, crankshaft rotating mechanism; 210, bracket; 211, first limit block; 212, second limit block; 220, rotating assembly; 230, obstacle avoidance mechanism; 231, rotating shaft; 232, rotating swing arm;

[0070] 300, lifting and positioning mechanism; 301, first lifting mechanism; 302, second lifting mechanism; 303, third lifting mechanism; 304, base; 305, third guide rail mounting plate; 306, support plate;

[0071] 400, bolt tightening unit; 410, frame; 411, lifting cylinder; 420, tightening pitch-changing mechanism; 421, first guide rail mounting plate; 422, first slider mounting plate; 423, telescopic cylinder; 424, angle fixing plate;

[0072] 430, bolt tightening mechanism; 431, second guide rail mounting plate; 432, second slider mounting plate; 433, bolt tightener; 434, lifter; 435, handle; 436, angle locking plate;

[0073] 440. Angle adjustment mechanism; 441. First hinge seat; 442. Second hinge seat; 443. Hinge shaft; 500. Engine cylinder block. DETAILED DESCRIPTION

[0074] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0075] The embodiment of the present application provides a three-cylinder engine block assembly production line and an assembly method thereof, which can solve the problems in the related art that the three-cylinder engine block assembly process is long or requires two workers to cooperate to complete the piston connecting rod group assembly, the assembly automation level is low, the assembly efficiency is low, and the cost is high.

[0076] See also Figures 1 to 3 As shown, the first aspect of the embodiment of the present application provides a three-cylinder engine cylinder block assembly production line, comprising:

[0077] The engine transmission line 100 includes an engine tray 110 for carrying the engine block 500 and a conveyor line 120 for transporting the engine tray 110 to the assembly station. The conveyor line 120 is provided with a plurality of rollers spaced along its length to rotatably support the engine tray 110. The rollers are connected by a transmission chain to collectively drive the engine tray 110 to move along the conveyor line 120 in a predetermined direction.

[0078] The engine tray 110 is a metal plate of a set thickness. A plurality of support limit blocks for positioning and supporting the engine cylinder block 500 are provided on the top of the engine tray 110. The engine cylinder block 500 is fixed on the support limit blocks of the engine tray 110 with its bottom facing upward, and the support limit blocks lift the engine cylinder block 500 upward to a set height, leaving a set height between the engine cylinder block 500 and the engine tray 110, which facilitates the installation of the piston and connecting rod in the cylinder hole of the engine cylinder block 500.

[0079] Lifting and positioning mechanism 300 is located below (at the bottom) the engine tray 110. It is used to lift the piston and connecting rod upward, moving them toward the crankshaft. Lifting and positioning mechanism 300 is used to lift the pistons and connecting rods within the three cylinder bores of the engine block 500, respectively, to position the big ends of the connecting rods closer to the connecting rod journals of the crankshaft, facilitating assembly of the connecting rod cap in the next step.

[0080] Crankshaft rotation mechanism 200, located at one end of engine tray 110, is used to rotate the crankshaft so that the big end of the connecting rod fits into the connecting rod journal. By rotating one end of the crankshaft, crankshaft rotation mechanism 200 aligns the connecting rod journal with the big end of the connecting rod in the corresponding cylinder bore, facilitating the pre-installation of the connecting rod cap onto the big end of the connecting rod.

[0081] The bolt tightening unit 400 is located above the engine tray 110 and is used to tighten the connecting rod cap to the connecting rod by tightening the bolts. When tightening the bolts, the bolt tightening unit 400 moves toward the engine tray 110 to engage the bolts. The bolt tightener 433 automatically tightens the bolts, thereby securing the connecting rod cap to the connecting rod's big end, completing the assembly.

[0082] The three-cylinder engine block assembly line of the present embodiment utilizes an engine transmission line 100 to transport the engine block 500 to a designated assembly station, thereby reducing worker workload, enabling streamlined assembly operations, and improving assembly efficiency. When connecting the piston-connecting rod assembly to the crankshaft, the lifting and positioning mechanism 300 is preferably used to lift the piston and connecting rod upward, moving them toward the crankshaft.

[0083] The crankshaft is then rotated using the crankshaft rotation mechanism 200 to align the connecting rod's big end with the crankshaft's connecting rod journal. Finally, the bolt tightening unit 400 tightens the connecting rod cap to the connecting rod, completing the automated assembly of the piston-connecting rod assembly, crankshaft, and engine block 500. This three-cylinder engine block assembly line can be operated by either a single operator or unmanned, significantly improving assembly efficiency and reducing production costs.

[0084] In some alternative embodiments: See Figures 4 to 6As shown, the embodiment of the present application provides a three-cylinder engine block assembly production line. The lifting and positioning mechanism 300 of the three-cylinder engine block assembly production line includes a base 304. A first lifting mechanism 301, a second lifting mechanism 302, and a third lifting mechanism 303 are arranged in sequence on the base 304. The first lifting mechanism 301, the second lifting mechanism 302, and the third lifting mechanism 303 all pass through the engine tray 110 through lifting motion and correspond one-to-one to the positions of the three cylinder holes of the engine block 500.

[0085] The lifting and positioning mechanism 300 of the present application comprises a first lifting mechanism 301, a second lifting mechanism 302, and a third lifting mechanism 303 arranged sequentially on a base 304. These first, second, and third lifting mechanisms 301, 302, and 303 are sequentially arranged to sequentially lift the pistons and connecting rods within the three cylinder bores of the engine block 500, bringing the connecting rod ends closer to the connecting rod journals of the crankshaft. The first, second, and third lifting mechanisms 301, 302, and 303 can be commercially available telescopic or linear drive mechanisms, such as electric cylinders, pneumatic cylinders, and hydraulic cylinders.

[0086] In some alternative embodiments: See Figure 7 and Figure 8 As shown, an embodiment of the present application provides a three-cylinder engine block assembly production line. The crankshaft rotation mechanism 200 of the three-cylinder engine block assembly production line includes a bracket 210, which is fixed to the ground or to the conveyor line 120. The crankshaft rotation mechanism 200 also includes a rotating assembly 220 located on the bracket 210 for connecting to one end of the crankshaft and driving the crankshaft to rotate to a set angle. An obstacle avoidance mechanism 230 is provided on the bracket 210 to drive the rotating assembly 220 to move toward or away from the engine block 500. The obstacle avoidance mechanism 230 is used to prevent the rotating assembly 220 from blocking the movement of the engine block 500, allowing the conveyor line 120 to transport the engine block 500 to the assembly station.

[0087] Specifically, the obstacle avoidance mechanism 230 includes a rotating swing arm 232, one end of which is rotatably connected to the bracket 210 via a rotating shaft 231. The other end of the rotating swing arm 232 is connected to the rotating assembly 220. The rotating assembly 220 includes a crankshaft shifter rotatably connected to the rotating swing arm 232, and the crankshaft shifter is connected to a handwheel or motor that drives the crankshaft shifter. One end of the rotating swing arm 232 rotates around the rotating shaft 231. A first limit block 211 and a second limit block 212 are provided at the top of the bracket 210 to limit the rotation angle of the rotating swing arm 232. The first limit block 211 and the second limit block 212 restrict the rotation of the rotating swing arm 232 within a range of 0-90 degrees.

[0088] To automate the operation of crankshaft rotation mechanism 200, those skilled in the art may further incorporate a rotary drive assembly on top of bracket 210 to drive swing arm 232 to rotate about rotation axis 231. This rotary drive assembly may be electrically driven or pneumatically driven. Rotation assembly 220 may further incorporate a servo motor to drive the crankshaft shifter, thereby rotating the crankshaft to a set angle and achieving alignment between the crankshaft connecting rod journal and the connecting rod's big end.

[0089] In some alternative embodiments: See Figure 3 As shown, the embodiment of the present application provides a three-cylinder engine block assembly production line. The bolt tightening unit 400 of the three-cylinder engine block assembly production line includes a frame 410. A tightening pitch-changing mechanism 420 is fixedly provided on the top of the frame 410. A bolt tightening mechanism 430 for tightening bolts is slidably connected to the tightening pitch-changing mechanism 420. The tightening pitch-changing mechanism 420 is used to drive the bolt tightening mechanism 430 to move along the length of the engine block 500, thereby causing the bolt tightening mechanism 430 to sequentially align with the three connecting rod caps in the engine block 500.

[0090] The bolt tightening unit 400 of the embodiment of the present application is provided with a frame 410. A tightening pitch-changing mechanism 420 is disposed on top of the frame 410 to move a bolt tightening mechanism 430 to a set tightening position. The tightening pitch-changing mechanism 420 has three working positions, each corresponding to the three cylinder bores of the engine block 500. For example, when the tightening pitch-changing mechanism 420 moves the bolt tightening mechanism 430 to the first working position, the bolt tightening mechanism 430 assembles and tightens the connecting rod cap and connecting rod in the first cylinder bore. The same process is repeated for the other two working positions.

[0091] In some alternative embodiments: See Figures 9 to 13 As shown, an embodiment of the present application provides a three-cylinder engine block assembly line. An angle adjustment mechanism 440 is provided between a tightening and pitch-changing mechanism 420 and a bolt tightening mechanism 430 for adjusting the pitch angle of the bolt tightening mechanism 430. The tightening and pitch-changing mechanism 420 includes a first guide rail mounting plate 421 and a first slider mounting plate 422 fixed to a frame 410. The first guide rail mounting plate 421 and the first slider mounting plate 422 are connected by a horizontal guide rail and a slider. The first slider mounting plate 422 reciprocates relative to the first guide rail mounting plate 421 under the guidance of the horizontal guide rail and the slider.

[0092] The angle adjustment mechanism 440 includes a first hinge 441 fixedly connected to the first slider mounting plate 422, and a second hinge 442 fixedly connected to the bolt tightening mechanism 430. The first hinge 441 and the second hinge 442 are rotatably connected via a hinge shaft 443. The second hinge 442 and the bolt tightening mechanism 430 move up and down about the hinge shaft 443, allowing the bolt tightening mechanism 430 to precisely align with the bolts securing the connecting rod cover. The bolt tightening mechanism 430 also includes an angle locking plate 436 fixedly connected to the first slider mounting plate 422. An angle fixing plate 424, which is connected to the angle locking plate 436, is fixedly attached to the first slider mounting plate 422. The angle fixing plate 424 and the angle locking plate 436 are connected via bolts.

[0093] The tightening and pitch-changing mechanism 420 also includes a telescopic cylinder 423 fixed to the first guide rail mounting plate 421 for driving the bolt tightening mechanism 430 along the length of the engine block 500. The telescopic cylinder 423 has three positions corresponding to the three cylinder bores of the engine block 500. When the telescopic cylinder 423 drives the bolt tightening mechanism 430 to the first cylinder bore position, the first lifting mechanism 301 of the lifting and positioning mechanism 300 lifts the piston and connecting rod in that cylinder bore upward, achieving a coordinated control signal between the telescopic cylinder 423 and the lifting and positioning mechanism 300.

[0094] In some alternative embodiments: See Figures 9 to 13 As shown, an embodiment of the present application provides a three-cylinder engine block assembly line. The bolt tightening mechanism 430 of the three-cylinder engine block assembly line includes a second guide rail mounting plate 431 and a second slider mounting plate 432. The second guide rail mounting plate 431 and the second slider mounting plate 432 are connected by vertical guide rails and sliders. The second slider mounting plate 432 reciprocates up and down relative to the second guide rail mounting plate 431 under the guidance of the vertical guide rails and sliders. Two bolt tighteners 433 arranged in parallel are fixedly connected to the second slider mounting plate 432. A lifter 434 is provided on the second guide rail mounting plate 431 to drive the bolt tighteners 433 up and down.

[0095] The bolt tightening mechanism 430 of the present embodiment is equipped with a second guide rail mounting plate 431 and a second slider mounting plate 432 that slide vertically relative to each other. The second guide rail mounting plate 431 is fixed to the angle adjustment mechanism 440. The second slider mounting plate 432 is an "L"-shaped structure used to fix two parallel bolt tighteners 433. The two bolt tighteners 433 are used to simultaneously tighten the two bolts at the end of the connecting rod cover. Between the second guide rail mounting plate 431 and the second slider mounting plate 432 is an elevator 434 that drives the bolt tighteners 433 to move up and down. This elevator 434 drives the bolt tighteners 433 to switch back and forth between the tightening position and the non-tightening position.

[0096] The lifter 434 can be a balanced cylinder. When a balanced cylinder is used, the bolt tightener 433 needs to be manually driven to move up and down. Therefore, two handles 435 for workers to hold are provided on the second slider mounting plate 432. The worker drives the bolt tightener 433 up and down by holding the handles 435. Of course, those skilled in the art of the lifter 434 can also use an automatically operated telescopic or linear movement mechanism such as an electric cylinder, a pneumatic cylinder, or an oil cylinder to drive the bolt tightener 433 up and down.

[0097] In some alternative embodiments: See Figures 3 to 6 and Figure 13 As shown, an embodiment of the present application provides a three-cylinder engine block assembly production line, and the bottom of the frame 410 of the three-cylinder engine block assembly production line is also provided with a lifting mechanism that drives the lifting and positioning mechanism 300 to move up and down, and the lifting mechanism includes a third guide rail mounting plate 305 fixed on the frame 410, and the third guide rail mounting plate 305 is connected to a support plate 306 through a vertical guide rail and a slider, the lifting and positioning mechanism 300 is fixed on the top of the support plate 306, and the frame 410 is also provided with a lifting cylinder 411 that drives the support plate to move up and down.

[0098] In the embodiment of the present application, a lifting mechanism is further provided at the bottom of the frame 410 for driving the lifting and positioning mechanism 300 to move up and down. The lifting mechanism is used to lift the lifting and positioning mechanism 300 so as to lift or lower the lifting and positioning mechanism 300 to a set height, thereby enabling the lifting and positioning mechanism 300 to lift the pistons and connecting rods in engine cylinders 500 of different specifications.

[0099] See also Figures 1 to 13 As shown, a second aspect of an embodiment of the present application provides an assembly method for a three-cylinder engine cylinder block assembly production line, the method using the three-cylinder engine cylinder block assembly production line described in any of the above embodiments, the method comprising:

[0100] Step 1: Assemble the piston and connecting rod and install them into the cylinder hole of the engine cylinder block 500, turn the engine cylinder block 500 so that the bottom is facing upward, and deflect the big end of the connecting rod toward the bolt tightening unit 400.

[0101] Step 2: Tighten the main shaft cover bolts to fix the crankshaft and the main shaft cover on the engine cylinder block 500, control the crankshaft rotation mechanism 200 to return it to the working position and connect it to the end of the crankshaft.

[0102] Step 3: Start the first lifting mechanism 301 of the lifting and positioning mechanism 300 to lift the piston and the connecting rod in the first cylinder hole upward, so that the piston and the connecting rod in the first cylinder hole move toward the crankshaft.

[0103] Step 4: Use the rotating assembly 220 of the crankshaft rotating mechanism 200 to rotate the crankshaft so that the big end of the connecting rod in the first cylinder hole fits into the connecting rod journal of the crankshaft.

[0104] Step 5: Pre-install the connecting rod cover and bolts in the first cylinder hole, tighten the bolts using the bolt tightener 433 of the bolt tightening unit 400 to fasten the connecting rod cover to the connecting rod, and lower the first lifting mechanism 301 of the lifting and positioning mechanism 300 to its original position.

[0105] Step 6: Start the third lifting mechanism 303 of the lifting and positioning mechanism 300 to lift the piston and connecting rod in the third cylinder hole upward, so that the piston and connecting rod in the third cylinder hole move toward the crankshaft.

[0106] Step 7: Use the rotating assembly 220 of the crankshaft rotating mechanism 200 to rotate the crankshaft so that the big end of the connecting rod in the third cylinder hole fits into the connecting rod journal of the crankshaft.

[0107] Step 8: Pre-install the connecting rod cover and bolts in the third cylinder hole, move the bolt tightening unit 400 to the top of the third cylinder hole, and use the bolt tightener 433 to tighten the bolts to fasten the connecting rod cover to the connecting rod, and lower the third lifting mechanism 303 of the lifting and positioning mechanism 300 to its original position.

[0108] Step 9: Start the second lifting mechanism 302 of the lifting and positioning mechanism 300 to lift the piston and connecting rod in the second cylinder hole upward, so that the piston and connecting rod in the second cylinder hole move toward the crankshaft.

[0109] Step 10: Use the rotating assembly 220 of the crankshaft rotating mechanism 200 to rotate the crankshaft so that the big end of the connecting rod in the second cylinder hole fits into the connecting rod journal of the crankshaft.

[0110] Step 11: Pre-install the connecting rod cover and bolts in the second cylinder hole, move the bolt tightening unit 400 to the top of the second cylinder hole, and use the bolt tightener 433 to tighten the bolts to fasten the connecting rod cover to the connecting rod, and the second lifting mechanism 302 of the lifting and positioning mechanism 300 is lowered to its original position.

[0111] Step 12: Control the crankshaft rotating mechanism 200 to disengage from the end of the crankshaft and return it to its original position, start the engine transmission line 100, and transfer the assembled engine cylinder block 500 to the next station.

[0112] How it works

[0113] An embodiment of the present application provides a three-cylinder engine block assembly production line and an assembly method thereof. Since the three-cylinder engine block assembly production line of the present application is provided with an engine transmission line 100, it includes an engine tray 110 for carrying an engine block 500 and a conveyor line 120 for conveying the engine tray 110 to an assembly station; a lifting and positioning mechanism 300, which is located below the engine tray 110, and is used to lift the piston and connecting rod upward so that the piston and connecting rod move toward the direction close to the crankshaft; a crankshaft rotation mechanism 200, which is located at one end of the engine tray 110, and is used to rotate the crankshaft so that the big end of the connecting rod fits into the connecting rod journal of the crankshaft; a bolt tightening unit 400, which is located above the engine tray 110, and is used to fasten the connecting rod cover to the connecting rod by tightening the bolts.

[0114] Therefore, the three-cylinder engine block assembly production line of the present application utilizes an engine transmission line 100 to transport the engine block 500 to a designated assembly station, thereby reducing worker labor and enabling streamlined assembly operations, thereby improving assembly efficiency. When connecting the piston-connecting rod assembly to the crankshaft, the lifting and positioning mechanism 300 is first used to lift the piston and connecting rod upward, moving them toward the crankshaft. The crankshaft is then rotated using the crankshaft rotation mechanism 200 to align the connecting rod's large end with the crankshaft's connecting rod journal. Finally, the bolt tightening unit 400 is used to tighten the connecting rod cap to the connecting rod, completing the automated assembly of the piston-connecting rod assembly, crankshaft, and engine block 500. This three-cylinder engine block assembly production line can be used for either single-person or unmanned automated assembly, significantly improving assembly efficiency and reducing production costs.

[0115] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0116] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0117] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. An assembly method for a three-cylinder engine cylinder block assembly production line, characterized in that: include: An engine transmission line (100), the engine transmission line (100) comprising an engine tray (110) for carrying an engine cylinder block (500) and a conveying line (120) for conveying the engine tray (110) to an assembly station; a lifting and positioning mechanism (300), the lifting and positioning mechanism (300) being located below the engine tray (110) and being used to lift the piston and the connecting rod upwards so as to move the piston and the connecting rod toward a direction close to the crankshaft; a crankshaft rotating mechanism (200), the crankshaft rotating mechanism (200) being located at one end of the engine tray (110) and being used to rotate the crankshaft so that the big end of the connecting rod fits into the connecting rod journal of the crankshaft; a bolt tightening unit (400), the bolt tightening unit (400) being located above the engine tray (110) and being used to fasten the connecting rod cover to the connecting rod by tightening the bolts; The method comprises: Assemble the piston and the connecting rod and install them into the cylinder hole of the engine cylinder block (500), turn the engine cylinder block (500) so that the bottom is facing upward, and deflect the large end of the connecting rod toward the bolt tightening unit (400); Tighten the main shaft end cover bolts to fix the crankshaft and the main shaft cover to the engine cylinder block (500), control the crankshaft rotation mechanism (200) to return it to the working position and connect it to the end of the crankshaft; activating the lifting and positioning mechanism (300) to lift the piston and the connecting rod in the first cylinder hole upward, so that the piston and the connecting rod in the first cylinder hole move toward a direction close to the crankshaft; The crankshaft is rotated by a crankshaft rotating mechanism (200) so that the big end of the connecting rod in the first cylinder hole fits into the connecting rod journal of the crankshaft; Pre-installing the connecting rod cover and bolts in the first cylinder hole, tightening the bolts using a bolt tightening unit (400) to fasten the connecting rod cover to the connecting rod, and lowering the lifting and positioning mechanism (300) to the original position; activating the lifting and positioning mechanism (300) to lift the piston and the connecting rod in the third cylinder hole upward, so that the piston and the connecting rod in the third cylinder hole move toward a direction close to the crankshaft; The crankshaft is rotated by a crankshaft rotating mechanism (200) so that the big end of the connecting rod in the third cylinder hole fits into the connecting rod journal of the crankshaft; Pre-install the connecting rod cover and bolts in the third cylinder hole, move the bolt tightening unit (400) to the top of the third cylinder hole, tighten the bolts to fasten the connecting rod cover to the connecting rod, and lower the lifting and positioning mechanism (300) to the original position; activating the lifting and positioning mechanism (300) to lift the piston and the connecting rod in the second cylinder hole upward, so that the piston and the connecting rod in the second cylinder hole move toward a direction close to the crankshaft; The crankshaft is rotated by a crankshaft rotating mechanism (200) so that the big end of the connecting rod in the second cylinder hole fits into the connecting rod journal of the crankshaft; Pre-install the connecting rod cover and bolts in the second cylinder hole, move the bolt tightening unit (400) to the top of the second cylinder hole, tighten the bolts to fasten the connecting rod cover to the connecting rod, and lower the lifting and positioning mechanism (300) to the original position; The crankshaft rotating mechanism (200) is controlled to disengage from the end of the crankshaft and return it to its original position, and the engine transmission line (100) is started to transfer the assembled engine cylinder block (500) to the next station.

2. The assembly method of a three-cylinder engine cylinder block assembly line according to claim 1, characterized in that: The lifting and positioning mechanism (300) comprises a base (304), on which a first lifting mechanism (301), a second lifting mechanism (302), and a third lifting mechanism (303) are sequentially arranged; The first lifting mechanism (301), the second lifting mechanism (302) and the third lifting mechanism (303) all pass through the engine tray (110) through lifting movements and correspond one-to-one to the positions of the three cylinder holes of the engine cylinder block (500).

3. The assembly method of a three-cylinder engine cylinder block assembly line according to claim 1, characterized in that: The crankshaft rotating mechanism (200) comprises a bracket (210), and a rotating assembly (220) located on the bracket (210) and used to connect to one end of the crankshaft and drive the crankshaft to rotate to a set angle; The bracket (210) is provided with an obstacle avoidance mechanism (230) for driving the rotating assembly (220) to move toward or away from the engine cylinder block (500), so that the conveyor line (120) conveys the engine cylinder block (500) to the assembly station.

4. The assembly method of a three-cylinder engine cylinder block assembly line according to claim 3, characterized in that: The obstacle avoidance mechanism (230) comprises a rotating swing arm (232), one end of the rotating swing arm (232) being rotatably connected to the bracket (210) via a rotating shaft (231), and the other end of the rotating swing arm (232) being connected to the rotating assembly (220); The rotating assembly (220) comprises a crankshaft shifter rotatably connected to the rotating swing arm (232), and the crankshaft shifter is connected to a handwheel or a motor for driving the crankshaft shifter to rotate.

5. The assembly method of a three-cylinder engine cylinder block assembly production line according to claim 1, characterized in that: The bolt tightening unit (400) comprises a frame (410), a tightening pitch-changing mechanism (420) is fixedly provided on the top of the frame (410), and a bolt tightening mechanism (430) for tightening bolts is slidably connected to the tightening pitch-changing mechanism (420); The tightening and pitch-changing mechanism (420) drives the bolt tightening mechanism (430) to move along the length direction of the engine cylinder (500), so that the bolt tightening mechanism (430) is aligned with the three connecting rod covers in the engine cylinder (500) in sequence.

6. The assembly method of a three-cylinder engine cylinder block assembly line according to claim 5, characterized in that: An angle adjustment mechanism (440) for adjusting the pitch angle of the bolt tightening mechanism (430) is provided between the tightening pitch changing mechanism (420) and the bolt tightening mechanism (430); The tightening and pitch-changing mechanism (420) comprises a first guide rail mounting plate (421) and a first slider mounting plate (422), wherein the first guide rail mounting plate (421) and the first slider mounting plate (422) are connected via a horizontal guide rail and a slider; The angle adjustment mechanism (440) includes a first hinge seat (441) fixedly connected to the first slider mounting plate (422), and a second hinge seat (442) fixedly connected to the bolt tightening mechanism (430); The first hinge seat (441) and the second hinge seat (442) are rotatably connected via a hinge shaft (443), and the bolt tightening mechanism (430) is further provided with an angle locking plate (436) fixedly connected to the first slider mounting plate (422).

7. The assembly method of a three-cylinder engine cylinder block assembly line according to claim 6, characterized in that: The tightening and pitch-changing mechanism (420) further includes a telescopic cylinder (423) fixed on the first guide rail mounting plate (421) for driving the bolt tightening mechanism (430) to move along the length direction of the engine cylinder block (500); The telescopic cylinder (423) is provided with three workstations corresponding one-to-one to the positions of the three cylinder holes of the engine cylinder block (500); When the telescopic cylinder (423) drives the bolt tightening mechanism (430) to a certain cylinder hole position, the lifting and positioning mechanism (300) lifts the piston and connecting rod centered in the cylinder hole upward.

8. The assembly method of a three-cylinder engine cylinder block assembly line according to claim 5, characterized in that: The bolt tightening mechanism (430) comprises a second guide rail mounting plate (431) and a second slider mounting plate (432), wherein the second guide rail mounting plate (431) and the second slider mounting plate (432) are connected via a vertical guide rail and a slider; Two parallel bolt tighteners (433) are fixedly connected to the second slider mounting plate (432), and a lifter (434) for driving the bolt tighteners (433) to move upward and downward is provided on the second guide rail mounting plate (431).

9. The assembly method of a three-cylinder engine cylinder block assembly line according to claim 5, characterized in that: The bottom of the frame (410) is further provided with a lifting mechanism for driving the lifting and positioning mechanism (300) to move up and down, and the lifting mechanism includes a third guide rail mounting plate (305) fixed to the frame (410); The third guide rail mounting plate (305) is connected to a support plate (306) via a vertical guide rail and a slider, the lifting and positioning mechanism (300) is fixed on the top of the support plate (306), and the frame (410) is further provided with a lifting cylinder (411) for driving the support plate (306) to move up and down.

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