Two-stroke engine box closing tool

Abstract

The utility model discloses a two-stroke engine box closing tool which comprises a press-fitting frame, a press-fitting assembly and a driving assembly, the press-fitting assembly is connected to the press-fitting frame, the driving assembly is arranged on the press-fitting frame, the driving assembly acts on the press-fitting assembly, and a half shaft on the corresponding side of a crankshaft connecting rod is connected with the press-fitting assembly. The press-fitting assembly is driven by the driving assembly, so that the bearing on the box body on the corresponding side is press-fitted on the half shaft on the corresponding side. The bearings are respectively pressed in the left box body and the right box body, when the left box body is pressed, the left half shaft of the crankshaft connecting rod is connected with the press-fitting assembly, the press-fitting assembly is controlled by the driving assembly, the left box body is pressed on the thrust surface of the crankshaft, then the right half shaft is connected with the press-fitting assembly, the press-fitting assembly is controlled by the driving assembly, and the left box body is pressed on the thrust surface of the crankshaft. The right box body is pressed on the thrust surface of the crankshaft, and in the whole pressing process, when the left box body is pressed, the left half shaft is stressed; and when the right box body is pressed, the right half shaft is stressed, so that the influence on the coaxiality of the left half shaft and the right half shaft is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of engine equipment technology, specifically relating to a tooling for assembling a two-stroke engine. Background Technology

[0002] Garden machinery powered by two-stroke gasoline engines, including lawnmowers and chainsaws, uses a core crankshaft connecting rod mechanism. The left and right crankshaft halves are manufactured separately and then connected by crank pins. The coaxiality of the two shafts at their diameters after connection is critical and generally requires individual calibration to ensure a tolerance between 0.02 and 0.04 mm. This coaxiality requirement must not be compromised during assembly.

[0003] To meet the requirements of high-speed operation (>10000rpm) and improve durability, the crankshaft diameter and bearing are mostly fitted with a small interference fit, with the diameter tolerance between (-0.002 to +0.005). Therefore, during assembly and disassembly, regardless of which part of the crankshaft is used for positioning, the coaxiality of the crankshaft will be damaged when installing bearings on another shaft. Utility Model Content

[0004] The purpose of this utility model is to solve the aforementioned technical problems existing in the prior art and to provide a two-stroke engine housing assembly tooling. The bearings are press-fitted into the left and right housings respectively. During the press-fitting of the left housing, the left half-shaft of the crankshaft connecting rod is connected to the press-fitting assembly. The press-fitting assembly is controlled by a drive assembly to press the left housing onto the crankshaft thrust surface. Then, the right half-shaft is connected to the press-fitting assembly, and the press-fitting assembly is controlled by a drive assembly to press the right housing onto the crankshaft thrust surface. Throughout the press-fitting process, the left half-shaft is stressed when pressing the left housing, and the right half-shaft is stressed when pressing the right housing, thus avoiding any impact on the coaxiality of the left and right half-shafts and greatly improving the housing assembly accuracy of the two-stroke engine.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A two-stroke engine housing assembly tooling includes a press-fit frame, a press-fit assembly, and a drive assembly. The press-fit assembly is connected to the press-fit frame, and the drive assembly is located on the press-fit frame. The drive assembly acts on the press-fit assembly. By connecting the half-shaft on the corresponding side of the crankshaft connecting rod to the press-fit assembly, the drive assembly drives the press-fit assembly, thereby press-fitting the bearing on the corresponding side of the housing onto the half-shaft on the corresponding side. This invention presses bearings into the left and right housings respectively. When pressing the left housing, the left half-shaft of the crankshaft connecting rod is connected to the pressing assembly. The pressing assembly is controlled by the drive assembly to press the left housing onto the crankshaft thrust surface. Then, the right half-shaft is connected to the pressing assembly, and the pressing assembly is controlled by the drive assembly to press the right housing onto the crankshaft thrust surface. During the entire pressing process, the left half-shaft is stressed when pressing the left housing, and the right half-shaft is stressed when pressing the right housing, thus avoiding any impact on the coaxiality of the left and right half-shafts and greatly improving the housing fitting accuracy of the two-stroke engine.

[0007] Furthermore, the press-fit frame includes a base plate, a press-fit platform, and support columns. The support columns are fixedly connected between the press-fit platform and the base plate, and the drive assembly is fixedly connected to the press-fit platform, thus forming an installation cavity between the press-fit platform and the base plate for press-fitting the housing and crankshaft connecting rod. The support columns provide support for the press-fit platform and simultaneously separate the base plate and the press-fit platform to form the installation cavity. The installation cavity facilitates the press-fitting of the housing and crankshaft connecting rod, ensuring sufficient installation space.

[0008] Furthermore, the drive assembly includes a press, a fixed base, and a connecting rod. The press is fixedly connected to the fixed base, and the connecting rod is fixedly attached to the bottom of the fixed base. The connecting rod is fixedly connected to the pressing frame, thus forming a pressing cavity between the fixed base and the pressing frame for connecting the pressing assembly. The connecting rod provides support to the fixed base and also separates the fixed base and the pressing frame to form a pressing cavity, facilitating the installation of the pressing assembly.

[0009] Furthermore, the press-fit assembly includes a rotary sleeve and a pressure rod. The height of the pressure rod is greater than the height of the rotary sleeve. The rotary sleeve has a through hole that matches the pressure rod, allowing the pressure rod to be inserted from the top of the rotary sleeve and exit from the bottom. The height of the pressure rod is greater than the height of the rotary sleeve, enabling it to be inserted from the through hole at the top of the rotary sleeve and exit from the through hole at the bottom, thus press-fitting the bearing housing onto the thrust surface of the crankshaft.

[0010] Furthermore, the rotary sleeve includes a limiting part and a connecting part. The diameter of the limiting part is larger than the diameter of the connecting part. The press-fit frame has a limiting mounting groove, which is matched with the connecting part, so that the connecting part passes through the limiting mounting groove and the limiting part abuts against the press-fit frame. The setting of the limiting part and the limiting mounting groove enable the rotary sleeve to be connected to the press-fit frame.

[0011] Furthermore, a connecting post is provided at the bottom of the through hole. The connecting post is fixed in the through hole by a rotating sleeve lug. An arc-shaped groove is formed between the through hole, the rotating sleeve lug, and the connecting post. The connecting post has a threaded connection hole, which is matched with the left and right half-shafts in the crankshaft connecting rod. The threaded connection hole in the connecting post allows the left and right half-shafts to be fixed to the connecting post by threads, thereby achieving the fixation of the press-fit assembly with the left and right half-shafts.

[0012] Furthermore, the pressure bar includes a pressure platform and an extrusion section. The diameter of the pressure platform is larger than the diameter of the extrusion section. The extrusion section has a hollow structure with a slot in the center and a notch at the bottom, forming an arc-shaped clamping part. The arc-shaped clamping part matches the arc-shaped slot, and the notch communicates with the slot hole. The notch matches the lug of the rotary sleeve. The drive assembly acts on the pressure platform. The pressure platform facilitates the operation of the press, the slot hole matches the connecting part, and the notch matches the lug of the rotary sleeve, so that when the pressure bar is pressed down by the press, the arc-shaped clamping part protrudes from the arc-shaped slot.

[0013] This utility model, by adopting the above-mentioned technical solution, has the following beneficial effects:

[0014] This invention presses bearings into the left and right housings respectively. When pressing the left housing, the left half-shaft of the crankshaft connecting rod is connected to the pressing assembly. The pressing assembly is controlled by the drive assembly to press the left housing onto the crankshaft thrust surface. Then, the right half-shaft is connected to the pressing assembly, and the pressing assembly is controlled by the drive assembly to press the right housing onto the crankshaft thrust surface. During the entire pressing process, the left half-shaft is stressed when pressing the left housing, and the right half-shaft is stressed when pressing the right housing, thus avoiding any impact on the coaxiality of the left and right half-shafts and greatly improving the housing fitting accuracy of the two-stroke engine.

[0015] The press-fit assembly of this utility model includes a rotary sleeve and a pressure rod. The height of the pressure rod is higher than the height of the rotary sleeve. The rotary sleeve has a through hole that matches the pressure rod, allowing the pressure rod to be inserted from the top of the rotary sleeve and exit from the bottom. The height of the pressure rod is higher than the height of the rotary sleeve, enabling it to be inserted from the through hole at the top of the rotary sleeve and exit from the through hole at the bottom, thus press-fitting the bearing housing onto the thrust surface of the crankshaft. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings:

[0017] Figure 1 This is a schematic diagram of the structure of a two-stroke engine assembly tooling according to the present invention;

[0018] Figure 2 This is a schematic diagram of the connection between the drive assembly and the press frame in this utility model;

[0019] Figure 3 This is a schematic diagram of the structure of one end of the rotary sleeve in this utility model;

[0020] Figure 4 This is a schematic diagram of the structure of the other end of the rotary sleeve in this utility model;

[0021] Figure 5 This is a schematic diagram of the structure of the pressure bar in this utility model;

[0022] Figure 6 This is a schematic diagram of the crankshaft connecting rod in this utility model;

[0023] Figure 7 This is a schematic diagram of the connection between the crankshaft connecting rod and the left and right housings in this utility model;

[0024] Figure 8 This is a schematic diagram of the structure in this utility model where the left housing is pressed onto the crankshaft thrust surface;

[0025] Figure 9 This is a schematic diagram of the structure in this utility model where the right housing is pressed onto the crankshaft thrust surface.

[0026] In the diagram, 1-pressing frame; 2-pressing assembly; 3-drive assembly; 4-base plate; 5-pressing platform; 6-support column; 7-mounting cavity; 8-press; 9-fixed seat; 10-connecting rod; 11-pressing cavity; 12-swivel sleeve; 13-pressure rod; 14-through hole; 15-limiting part; 16-connecting part; 17-limiting mounting groove; 18-connecting column; 19-swivel sleeve ear; 20-arc groove; 21-threaded connection hole; 22-pressure platform; 23-extrusion part; 24-slot hole; 25-groove opening; 26-arc clamping part; 27-crankshaft connecting rod; 28-left half-shaft; 29-right half-shaft; 30-left housing; 31-right housing. Detailed Implementation

[0027] like Figures 1 to 9 As shown, this utility model discloses a two-stroke engine housing assembly tooling, including a press-fit frame 1, a press-fit assembly 2, and a drive assembly 3. The press-fit assembly 2 is connected to the press-fit frame 1, and the drive assembly 3 is disposed on the press-fit frame 1. The drive assembly 3 acts on the press-fit assembly 2. By connecting the half-shaft on the corresponding side of the crankshaft connecting rod 27 to the press-fit assembly 2, the drive assembly 3 drives the press-fit assembly 2, thereby pressing the bearing on the corresponding side of the housing onto the half-shaft on the corresponding side.

[0028] The press-fit frame 1 includes a base plate 4, a press-fit platform 5, and a support column 6. The support column 6 is fixedly connected between the press-fit platform 5 and the base plate 4. The drive assembly 3 is fixedly connected to the press-fit platform 5, forming a mounting cavity 7 between the press-fit platform 5 and the base plate 4 for press-fitting the housing and crankshaft connecting rod 27. The support column 6 provides support for the press-fit platform 5 and simultaneously separates the base plate 4 and the press-fit platform 5 to form the mounting cavity 7. The mounting cavity 7 facilitates the press-fitting of the housing and crankshaft connecting rod 27, ensuring sufficient installation space.

[0029] The drive assembly 3 includes a press 8, a fixed base 9, and a connecting rod 10. The press 8 is fixedly connected to the fixed base 9, and the connecting rod 10 is fixedly attached to the bottom of the fixed base 9. The connecting rod 10 is fixedly connected to the pressing frame 1, forming a pressing cavity 11 between the fixed base 9 and the pressing frame 1 for connecting the pressing assembly 2. The connecting rod 10 provides support for the fixed base 9 and also separates the fixed base 9 from the pressing frame 1 to form the pressing cavity 11, facilitating the installation of the pressing assembly 2.

[0030] The press-fit assembly 2 includes a rotary sleeve 12 and a pressure rod 13. The height of the pressure rod 13 is greater than the height of the rotary sleeve 12. The rotary sleeve 12 has a through hole 14, which is matched with the pressure rod 13, so that the pressure rod 13 is inserted from the top of the rotary sleeve 12 and exits from the bottom of the rotary sleeve 12. The height of the pressure rod 13 is greater than the height of the rotary sleeve 12, so that after the pressure rod 13 is inserted into the through hole 14 at the top of the rotary sleeve 12, it can exit from the through hole 14 at the bottom of the rotary sleeve 12, thereby pressing the bearing housing onto the thrust surface of the crankshaft.

[0031] The rotary sleeve 12 includes a limiting part 15 and a connecting part 16. The diameter of the limiting part 15 is larger than the diameter of the connecting part 16. The press-fit frame 1 has a limiting mounting groove 17, which is matched with the connecting part 16 so that the connecting part 16 passes through the limiting mounting groove 17 and the limiting part 15 abuts against the press-fit frame 1. The setting of the limiting part 15 and the limiting mounting groove 17 enable the rotary sleeve 12 to be connected to the press-fit frame 1.

[0032] A connecting post 18 is provided at the bottom of the through hole 14. The connecting post 18 is fixed in the through hole 14 by a rotating sleeve ear 19. An arc-shaped groove 20 is formed between the through hole 14, the rotating sleeve ear 19, and the connecting post 18. The connecting post 18 is provided with a threaded connecting hole 21, which is matched with the left half-shaft 28 and the right half-shaft 29 in the crankshaft connecting rod 27. The threaded connecting hole 21 in the connecting post 18 allows the left half-shaft 28 and the right half-shaft 29 to be fixed to the connecting post 18 by threads, thereby realizing the fixation of the press-fit assembly 2 with the left half-shaft 28 and the right half-shaft 29.

[0033] The pressure rod 13 includes a pressure platform 22 and an extrusion part 23. The diameter of the pressure platform 22 is larger than the diameter of the extrusion part 23. The extrusion part 23 has a hollow structure with a slot 24 at its center and a slot 25 at its bottom, forming an arc-shaped pressing part 26. The arc-shaped pressing part 26 matches the arc-shaped slot 20. The slot 25 communicates with the slot 24 and matches the rotating sleeve ear 19. The drive assembly acts on the pressure platform 22. The pressure platform 22 is designed to facilitate the drive of the press 8. The slot 24 matches the connecting part 16, and the slot 25 matches the rotating sleeve ear 19, so that when the pressure rod 13 is pressed down by the press 8, the arc-shaped pressing part 26 protrudes from the arc-shaped slot 20.

[0034] This invention presses bearings into the left housing 30 and the right housing 31 respectively. When pressing the left housing 30, the left half-shaft 28 of the crankshaft connecting rod 27 is connected to the pressing assembly 2. The pressing assembly 2 is controlled by the drive assembly 3 to press the left housing 30 onto the crankshaft thrust surface. Then, the right half-shaft 29 is connected to the pressing assembly 2. The pressing assembly 2 is controlled by the drive assembly 3 to press the right housing 31 onto the crankshaft thrust surface. During the entire pressing process, the left half-shaft 28 is stressed when pressing the left housing 30, and the right half-shaft 29 is stressed when pressing the right housing 31. This avoids affecting the coaxiality of the left half-shaft 28 and the right half-shaft 29, and greatly improves the housing fitting accuracy of the two-stroke engine.

[0035] The above are merely specific embodiments of this utility model, but the technical features of this utility model are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on this utility model to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of this utility model.

Claims

1. A tooling for assembling a two-stroke engine housing, characterized in that: It includes a press-fit frame, a press-fit assembly, and a drive assembly. The press-fit assembly is connected to the press-fit frame, and the drive assembly is located on the press-fit frame. The drive assembly acts on the press-fit assembly. By connecting the half-shaft on the corresponding side of the crankshaft connecting rod to the press-fit assembly, the drive assembly drives the press-fit assembly, thereby press-fitting the bearing on the corresponding side of the housing onto the half-shaft on the corresponding side.

2. The two-stroke engine assembly fixture according to claim 1, characterized in that: The press-fitting frame includes a base plate, a press-fitting platform, and a support column. The support column is fixedly connected between the press-fitting platform and the base plate. The drive assembly is fixedly connected to the press-fitting platform, so that an installation cavity for press-fitting the housing and crankshaft connecting rod is formed between the press-fitting platform and the base plate.

3. The two-stroke engine assembly fixture according to claim 1, characterized in that: The drive assembly includes a press, a fixed base, and a connecting rod. The press is fixedly connected to the fixed base, and the connecting rod is fixedly connected to the bottom of the fixed base. The connecting rod is fixedly connected to the pressing frame, so that a pressing cavity for connecting the pressing assembly is formed between the fixed base and the pressing frame.

4. The two-stroke engine assembly fixture according to claim 1, characterized in that: The press-fit assembly includes a rotary sleeve and a pressure rod. The height of the pressure rod is higher than the height of the rotary sleeve. The rotary sleeve has a through hole, which is matched with the pressure rod so that the pressure rod is inserted from the top of the rotary sleeve and then exits from the bottom of the rotary sleeve.

5. The two-stroke engine assembly fixture according to claim 4, characterized in that: The rotary sleeve includes a limiting part and a connecting part. The diameter of the limiting part is larger than the diameter of the connecting part. The press-fit frame has a limiting mounting groove. The limiting mounting groove is matched with the connecting part so that the connecting part passes through the limiting mounting groove and the limiting part abuts against the press-fit frame.

6. The two-stroke engine assembly fixture according to claim 4, characterized in that: A connecting post is provided at the bottom of the through hole. The connecting post is fixed in the through hole by a rotating sleeve lug. An arc-shaped groove is formed between the through hole, the rotating sleeve lug, and the connecting post. The connecting post is provided with a threaded connection hole, which is matched with the left and right half-shafts in the crankshaft connecting rod.

7. The two-stroke engine assembly fixture according to claim 6, characterized in that: The pressure rod includes a pressure receiving platform and an extrusion part. The diameter of the pressure receiving platform is larger than the diameter of the extrusion part. The extrusion part has a hollow structure and a slot at its center. A slot is opened at the bottom of the extrusion part, forming an arc-shaped pressing part at the bottom of the extrusion part. The arc-shaped pressing part is matched with the arc-shaped slot. The slot communicates with the slot and is matched with the rotating sleeve lug. The driving component acts on the pressure receiving platform.

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