Portable testing tool for checking the mounting angle of a crankshaft gear

Abstract

A portable gauge for checking the installation angle of a crankshaft gear, used in the field of automobile parts manufacturing technology. The portable gauge for checking the installation angle of the crankshaft gear is composed of a bracket one, a bracket two and a measuring block; the left side of the bracket one is provided with a tooth tip block and a main shaft block, the inner diameter of the main shaft block is consistent with the outer diameter of the main shaft neck of the crankshaft, and the inner diameter of the tooth tip block is consistent with the outer diameter of the tooth tip circle of the gear; one side of the measuring block is a contrast plane, and the other side is a detection boss. The utility model can realize full detection confirmation of the gear angle of the crankshaft in mass production of the crankshaft, can quickly judge whether the installation angle of the gear on the crankshaft is qualified, has the advantages of low cost, portability and efficient detection, can effectively improve the gear installation angle precision and the comprehensive performance of the engine, prolong the service life of the engine, reduce oil consumption, and plays a crucial role in improving the stable operation and efficient output of the whole engine.

Description

Technical Field

[0001] This utility model relates to the field of automotive parts manufacturing technology, specifically a portable inspection tool for checking the installation angle of crankshaft gears. Background Technology

[0002] In the precision transmission system of a diesel engine, the mounting angle of the gears on the crankshaft is not arbitrarily set, but must be strictly controlled within a specific tolerance range. This seemingly minor angular deviation actually plays a crucial role in the smooth operation and efficient output of the entire engine. If the mounting angle exceeds the tolerance, it may lead to poor gear meshing, causing abnormal noise, increased vibration, and even accelerated wear of gears and bearings. Furthermore, when the gears drive the camshaft, an out-of-tolerance mounting angle can also affect the engine's valve timing or fuel injection timing, thereby reducing engine performance, increasing fuel consumption, and shortening its service life.

[0003] Existing methods for inspecting gear installation angles typically employ a dedicated, large-scale measuring fixture capable of providing precise readings of the gear angles. During measurement, the crankshaft is horizontally supported, and the marked teeth of the crankshaft gear are fixed to one side of the fixture. On the other side, a measuring tool is used to check the height of the crankshaft journal, which serves as the measurement reference. By comparing the measured height with the theoretical height, the specific angular deviation is determined, thus judging whether the crankshaft gear installation conforms to the process specifications. This method provides a precise reading of the gear installation angle deviation and has the advantage of adjusting the angle towards the median value during gear installation. However, this inspection method requires a large fixture table, resulting in drawbacks such as large space occupation, high cost, complex inspection process, and long inspection time, making it unsuitable for batch full inspection of gear installation angle deviations. Therefore, researching a portable fixture for inspecting crankshaft gear installation angles is particularly important. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the purpose of this invention is to provide a portable inspection tool for checking the installation angle of crankshaft gears, so as to achieve the purpose of conveniently and quickly performing a full inspection of the gear installation angle.

[0005] To achieve the above-mentioned invention objectives, the portable inspection tool for inspecting the installation angle of crankshaft gears of this utility model consists of a bracket 1, a bracket 2, and a measuring block; the left side of the bracket 1 is provided with a tooth tip pad and a main bearing pad, the inner diameter of the main bearing pad is consistent with the outer diameter of the crankshaft main journal, and the inner diameter of the tooth tip pad is consistent with the outer diameter of the tooth tip circle of the gear; one side of the measuring block is a reference plane, and the other side is a detection boss.

[0006] Furthermore, the bracket is an L-shaped structure, with the tooth top bearing and the main bearing on its left side being an integral fan-shaped structure, and a step provided at the connection between the tooth top bearing and the main bearing; during inspection, the inner side of the fan-shaped structure of the main bearing is in contact with the main journal of the crankshaft, the inner side of the fan-shaped structure of the tooth top bearing is in contact with the tooth tip circle of the gear of the crankshaft, and the step plane at the connection between the tooth top bearing and the main bearing is in contact with the end face of the gear.

[0007] Furthermore, two through holes are opened on the right side of the bracket one, and bolts are used to connect and fix the bracket one to the bracket two. The two inner end faces of the bracket two slide with the connecting rod journal of the crankshaft.

[0008] Furthermore, the right side of bracket one is embedded in the groove of bracket two, and the center lines of symmetry of bracket one and bracket two coincide.

[0009] Furthermore, a detection window is opened on the tooth top pad. The center line of the detection window makes an angle α with the center line of the connecting rod journal of the crankshaft. This angle α is equal to the angle α between the center line of the tooth groove adjacent to the marked tooth of the gear and the center line of the connecting rod journal. A plane is milled on the outside of the tooth top pad perpendicular to the center line of the detection window as an inspection reference surface.

[0010] Furthermore, the cross-section of the detection boss of the measuring block is a semi-circular arc-shaped boss structure. The distance between the center of the semi-circular arc and the reference plane is H. This distance H is equal to the vertical distance H from the inspection reference plane to the crossbar distance circle. The center of symmetry of the cross-section of the detection boss at the end face L of the measuring block coincides with the center line of the measuring block. The distance between the detection boss and the end face L of the measuring block is equal to the distance L between the reference plane of the marking tooth and the end face of the gear. During inspection, the measuring block is placed along the detection window, and the detection boss is embedded in the tooth groove of the gear.

[0011] Furthermore, the support frame is connected to the measuring block using a fixed rope.

[0012] Compared with the prior art, this utility model can realize full inspection and confirmation of crankshaft gear angle in crankshaft mass production, and can quickly judge whether the gear installation angle on the crankshaft is qualified. It has the advantages of low cost, portability and high efficiency of inspection. It can effectively improve the accuracy of gear installation angle and the overall performance of the engine, extend the service life of the engine, reduce fuel consumption, and play a vital role in improving the smooth operation and efficient output of the entire engine. Attached Figure Description

[0013] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0014] Figure 1 This is a simplified structural diagram of the present invention in its application state.

[0015] Figure 2 for Figure 1 The left view.

[0016] Figure 3 for Figure 1 Cross-sectional view of the central support structure.

[0017] Figure 4 for Figure 1 Front view of the middle bracket.

[0018] Figure 5 for Figure 1 Front view of the second support bracket.

[0019] Figure 6 for Figure 1 A simplified structural diagram of the measuring block.

[0020] Figure 7 for Figure 6 AA sectional view.

[0021] Figure 8 This is a schematic diagram illustrating the inspection principle for determining if the gear installation angle is unqualified according to this utility model.

[0022] Figure 9 This is a schematic diagram illustrating the inspection principle for determining whether the gear installation angle is qualified according to this utility model.

[0023] In the diagram: 1. Bracket 1; 2. Bolt; 3. Bracket 2; 4. Connecting rod journal; 5. Main shaft journal; 6. Gear; 7. Crossbar spacing circle; 8. Fixing rope; 9. Measuring block; 10. Inspection datum surface; 11. Tooth top bearing block; 12. Comparison plane; 13. Inspection boss; 14. Main shaft bearing block; 15. Inspection window; 16. Datum surface; 17. Marking tooth; 18. Gear end face. Detailed Implementation

[0024] To make the invention's objectives, technical solutions, and advantages clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the scope of protection of the present invention.

[0025] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 As shown, the portable inspection tool for inspecting the installation angle of crankshaft gears according to this utility model mainly consists of bracket 1, bracket 2 3, and measuring block 9.

[0026] The bracket 1 is an L-shaped steel structure. On the left side of the bracket 1 are a toothed bearing 11 and a main bearing 14. The toothed bearing 11 and the main bearing 14 are an integral fan-shaped structure. A step is provided at the connection between the toothed bearing 11 and the main bearing 14. The inner diameter of the main bearing 14 is the same as the outer diameter of the crankshaft main journal 5, and the inner diameter of the toothed bearing 11 is the same as the outer diameter of the addendum circle of the gear 6. During inspection, the inner side of the fan-shaped structure of the main bearing 14 is fitted against the crankshaft main journal 5, the inner side of the fan-shaped structure of the toothed bearing 11 is fitted against the addendum circle of the gear 6 on the crankshaft, and the stepped plane at the connection between the toothed bearing 11 and the main bearing 14 is fitted against the gear end face 18 of the gear 6.

[0027] The right side of bracket 1 is embedded in the groove of bracket 2 3. There are two through holes on the right side of bracket 1. Bolt 2 connects and fixes bracket 1 and bracket 2 3 through the two through holes. Bracket 1 and bracket 2 3 are tightly fitted to ensure that the symmetrical center lines of bracket 1 and bracket 2 3 coincide after assembly. The two inner end faces of bracket 2 3 are in sliding fit with the connecting rod journal 4 of the crankshaft.

[0028] A detection window 15 is opened on the tooth top pad 11 of the bracket 1. The center line of the detection window 15 makes an angle α with the center line of the connecting rod neck 4 of the crankshaft. This angle α is equal to the angle α between the center line of the tooth groove adjacent to the marked tooth 17 of the gear 6 and the center line of the connecting rod neck 4. A plane is milled on the outside of the tooth top pad 11 perpendicular to the center line of the detection window 15 as an inspection reference surface 10.

[0029] One side of the measuring block 9 is the reference plane 12, and the other side is the detection boss 13. The cross-section of the detection boss 13 of the measuring block 9 is a semi-circular arc-shaped boss structure. The distance H between the center of the semi-circular arc and the reference plane 12 is equal to the perpendicular distance H from the inspection reference plane 10 to the crossbar distance circle 7. The center of symmetry of the cross-section of the detection boss 13 at a distance L from the end face of the measuring block 9 coincides with the center line of the measuring block 9. The distance between the detection boss 13 and the end face L of the measuring block 9 is equal to the distance L between the reference plane 16 of the marking tooth 17 and the end face 18 of the gear. The bracket 1 is connected to the measuring block 9 by a fixing rope 8 to prevent the measuring block 9 from being lost during use. During inspection, the measuring block 9 is placed along the inspection window 15, and the detection boss 13 is embedded in the tooth groove of the gear 6.

[0030] The mounting angle α1 of gear 6 is defined as the angle formed between a reference line passing through the center of the first connecting rod neck 4 of the crankshaft and perpendicular to the crankshaft axis, and the center line of symmetry of the reference surface 16 of the gear marking tooth 17. Its tolerance is ±θ, where the reference surface 16 of the marking tooth 17 is a section located at a distance L from the gear end face 18. The gear 6 mounted on the crankshaft is a helical gear with a helix angle of β. This invention can also be applied to spur gears, in which case β would be 0°.

[0031] This invention fully utilizes the characteristics of the crossbar distance circle 7 on gear 6. When a measuring rod with diameter d is placed in the tooth groove of gear 6 and is in a stable position, the center of the measuring rod will lie on a specific circle with diameter Dm centered at the center of gear 6; this circle is the crossbar distance circle 7. Typically, gear drawings will specify the exact values ​​of the diameter d of the measuring rod and the diameter Dm of the crossbar distance circle 7. This invention utilizes the known parameters diameter d and diameter Dm to create a portable inspection tool for checking the installation angle of crankshaft gears, using the theoretical crossbar distance circle 7 of gear 6 as the benchmark for comparison.

[0032] The centerline of the marked tooth 17 of gear 6 on the reference surface 16 at a distance L from the gear end face 18 makes an angle α1 with the centerline of the connecting rod neck 4. Therefore, the angle between the centerline of the adjacent tooth groove of marked tooth 17 and the centerline of the connecting rod neck 4 is α. According to the gear structure, α = α1 - 360° / number of teeth × 2. A detection window 15 is opened on the tooth top plate 11, and the angle between the centerline of this detection window 15 and the centerline of the connecting rod neck 4 of the crankshaft is α. A plane is milled perpendicular to the centerline of the detection window 15 on the outside of the tooth top plate 11 as an inspection reference surface 10. The vertical distance from the inspection reference surface 10 to the crossbar distance circle 7 is H.

[0033] When the installation angle α1 of gear 6 is α1+θ or α1-θ, the offset of the center of the marking tooth 17 on the span-bar circle 7 is ±Dm / 2×sinθ. Therefore, the semi-circular diameter d1 of the head of the detection boss 13 is d1 = d - 2×Dm / 2×sinθ = d - Dm×sinθ. Simultaneously, let H be the vertical distance from the center of the arc of the detection boss 13 to the reference plane 12. The center of symmetry of the section at the end face L of the measuring block 9 of the detection boss 13 coincides with the centerline of the measuring block 9. The inclination angle of the detection boss 13 is β, consistent with the helix of gear 6. During testing, the detection boss 13 can enter the adjacent tooth groove of the marking tooth of gear 6.

[0034] When the installation angle of gear 6 is out of tolerance, the semi-circular area of ​​measuring boss 13 can only contact the teeth of gear 6 on one side, while the other side is suspended. Measuring block 9 is lifted up, and the reference plane 12 will be higher than the inspection reference plane 10. The inspector can then conclude that the inspection result is unqualified.

[0035] When the installation angle of gear 6 is qualified, the semi-circular arc diameter d1 of the boss 13 is less than d. During the inspection, the measuring block 9 sinks, and the reference plane 12 will be lower than the inspection reference plane 10. The inspector can then conclude that the inspection result is qualified.

Claims

1. A portable inspection tool for checking the installation angle of crankshaft gears, characterized in that: The portable inspection tool for checking the installation angle of crankshaft gear consists of bracket one (1), bracket two (3) and measuring block (9); bracket one (1) has a tooth top bearing block (11) and a main bearing block (14) on its left side. The inner diameter of the main bearing block (14) is consistent with the outer diameter of the main journal (5) of the crankshaft, and the inner diameter of the tooth top bearing block (11) is consistent with the outer diameter of the tooth top circle of the gear (6); one side of the measuring block (9) is a reference plane (12), and the other side is a detection boss (13).

2. The portable inspection tool for inspecting the installation angle of crankshaft gears according to claim 1, characterized in that: The bracket (1) is an L-shaped structure. The tooth top pad (11) on its left side and the main shaft pad (14) are an integral fan-shaped structure. A step is provided at the connection between the tooth top pad (11) and the main shaft pad (14). During inspection, the inner side of the fan-shaped structure of the main shaft pad (14) is in contact with the main journal (5) of the crankshaft, the inner side of the fan-shaped structure of the tooth top pad (11) is in contact with the tooth tip circle of the gear (6) of the crankshaft, and the step plane at the connection between the tooth top pad (11) and the main shaft pad (14) is in contact with the gear end face (18).

3. The portable inspection tool for inspecting the installation angle of crankshaft gears according to claim 1, characterized in that: The right side of bracket one (1) has two through holes. Bolt (2) connects and fixes bracket one (1) and bracket two (3). The two inner end faces of bracket two (3) slide with the connecting rod neck (4) of the crankshaft.

4. A portable inspection tool for inspecting the installation angle of crankshaft gears according to claim 1, characterized in that: The right side of bracket one (1) is embedded in the groove of bracket two (3), and the center lines of symmetry of bracket one (1) and bracket two (3) coincide.

5. A portable inspection tool for inspecting the installation angle of crankshaft gears according to claim 1, characterized in that: A detection window (15) is opened on the tooth top pad (11). The center line of the detection window (15) makes an angle α with the center line of the connecting rod journal (4) of the crankshaft. This angle α is equal to the angle α between the center line of the tooth groove adjacent to the marked tooth (17) of the gear (6) and the center line of the connecting rod journal (4). A plane is milled on the outside of the tooth top pad (11) perpendicular to the center line of the detection window (15) as an inspection reference surface (10).

6. A portable inspection tool for inspecting the installation angle of crankshaft gears according to claim 1, characterized in that: The cross-section of the detection boss (13) of the measuring block (9) is a semi-circular arc-shaped boss structure. The distance between the center of the semi-circular arc and the reference plane (12) is H. This distance H is equal to the vertical distance H from the inspection reference plane (10) to the crossbar distance circle (7). The center of symmetry of the cross-section of the detection boss (13) at the end face L of the measuring block (9) coincides with the center line of the measuring block (9). The distance between the detection boss (13) and the end face L of the measuring block (9) is equal to the distance L between the reference plane (16) of the marking tooth (17) and the end face (18) of the gear. During inspection, the measuring block (9) is placed along the detection window (15), and the detection boss (13) is embedded in the tooth groove of the gear (6).

7. A portable inspection tool for inspecting the installation angle of crankshaft gears according to claim 1, characterized in that: The support (1) and the measuring block (9) are connected by a fixing rope (8).

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