Gear shifting structure of engine

Abstract

The utility model discloses an engine gear shifting structure which comprises a crankcase shell assembly, a speed change drum assembly, a positioning assembly and a gear shifting control arm, the gear shifting control arm rotates to drive the speed change drum assembly to rotate so as to achieve gear shifting, and the positioning assembly is used for preventing gear disengaging after gear shifting. The speed change drum assembly is rotationally arranged in the crankcase shell assembly, and the speed change drum assembly is provided with a sliding pin; the gear shifting control arm comprises an inner arm and an outer arm, the inner arm is rotationally arranged in the crankcase shell assembly, the outer arm is connected with the inner arm, the outer arm extends to the outside of the crankcase shell assembly, a control handle is arranged on the inner arm, a sliding groove is formed in the control handle, and the inner arm is connected with the outer arm. The length direction of the sliding groove is in the radial direction of the gear shifting control arm, and the sliding groove is in sliding fit with the sliding pin. The gear shifting control arm is simple in structure and small in occupied space.

Description

Technical Field

[0001] This utility model relates to motorcycle engines, specifically to an engine shifting structure. Background Technology

[0002] In motorcycle gear shifting, the transmission components of the crankcase drive the shift drum to rotate, and a positioning component locks the angle to match different gear requirements, thus completing the shifting process. Current mainstream technologies suffer from complex transmission and positioning mechanisms, resulting in a large crankcase footprint, which hinders crankcase miniaturization and weight reduction.

[0003] CN210510250U discloses a motorcycle gearbox shifting structure, including a connecting rod passing through the gearbox housing. The connecting rod has a fixed shifter and a movable shifter at its end. The fixed shifter is fixedly mounted on the connecting rod, and the movable shifter is sleeved on the connecting rod and slides in cooperation with the fixed shifter. A return spring is provided between the fixed and movable shifters, and a torsion spring is provided between the fixed shifter and the connecting rod. A protrusion on the housing cooperates with the fixed shifter, and the protrusion has two adjacent limiting surfaces. The fixed shifter has two retaining edges adapted to the protrusion. After being twisted and swung, one side of the fixed shifter contacts the limiting surface of the protrusion, and the limiting surface blocks the travel. Undoubtedly, the technical solution disclosed in the above patent document is a beneficial attempt in the relevant technical field. However, because the connecting rod occupies a large amount of internal space in the housing and requires the coordinated cooperation of the fixed and movable shifters at the end of the connecting rod, there is still room for further improvement. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide an engine shifting structure. The shifting control arm has a simple structure, occupies less space, and the layout of the crankcase components is more compact, which is conducive to the miniaturization and weight reduction of the crankcase.

[0005] This utility model discloses an engine shifting structure, including a crankcase housing assembly, a transmission drum assembly, a positioning assembly, and a shift control arm. Rotation of the shift control arm drives the transmission drum assembly to rotate, thereby achieving gear shifting. The positioning assembly prevents disengagement after gear shifting. The transmission drum assembly is rotatably disposed within the crankcase housing assembly and is provided with a sliding pin. The shift control arm includes an inner arm and an outer arm. The inner arm is rotatably disposed inside the crankcase housing assembly, and the outer arm is connected to the inner arm and extends to the outside of the crankcase housing assembly. An operating handle is provided on the inner arm, and a sliding groove is provided on the operating handle. The length direction of the sliding groove is along the radial direction of the shift control arm, and the sliding groove slides in cooperation with the sliding pin. The rotation axis of the shift control arm, the rotation axis of the transmission drum assembly, and the central axis of the sliding pin are all non-coincident and parallel to each other.

[0006] Furthermore, the crankcase housing assembly includes a crankcase body and a crankcase cover connected to the crankcase body, and the crankcase cover is provided with a clearance arc-shaped groove corresponding to the position of the outer arm.

[0007] Furthermore, the outer arm includes a spline segment and a threaded segment, the spline segment being connected to the inner arm, and the threaded segment being located on the side of the spline segment away from the inner arm.

[0008] Furthermore, the inner arm includes a first connecting section, a second connecting section, and a third connecting section connected in sequence. The first connecting section is rotatably engaged with the crankcase, and an oil seal is provided between the third connecting section and the crankcase cover. The operating handle is located at one end of the first connecting section near the second connecting section.

[0009] Furthermore, a limiting sector is provided at one end of the second connecting segment near the first connecting segment, and a limiting contact surface is provided on the crankcase cover corresponding to the position of the limiting sector.

[0010] Furthermore, the gear shift drum assembly includes a gear shift drum body and a star wheel body disposed at one end of the gear shift drum body, the middle part of the star wheel body being connected to the gear shift drum body by a first bolt.

[0011] Furthermore, a positioning pin is provided on the gearbox body, and a positioning hole is provided on the star wheel body. The positioning pin is inserted into the positioning hole, and the end of the positioning pin does not protrude from the positioning hole.

[0012] Furthermore, the central axis of the first bolt coincides with the rotation axis of the gear shift drum assembly, and the central axis of the positioning hole coincides with the central axis of the positioning pin; the rotation axis of the shift control arm, the central axis of the positioning hole, the rotation axis of the gear shift drum assembly, and the central axis of the sliding pin are arranged sequentially in the vertical direction and are all parallel to each other.

[0013] Furthermore, the star wheel body is a four-star wheel, and the outer contour of the star wheel body is provided with a reverse gear positioning groove, a neutral gear positioning groove and a forward gear positioning groove, with the neutral gear positioning groove located between the reverse gear positioning groove and the forward gear positioning groove.

[0014] Furthermore, the positioning assembly includes a positioning member and a torsion spring. The first end of the positioning member is provided with a first mounting hole, the tail end of the positioning member is provided with a rotatable positioning roller, and the middle part of the positioning member is provided with a second mounting hole. The middle part of the torsion spring and the first mounting hole are rotatably mounted to the crankcase housing assembly by a second bolt. One end of the torsion spring abuts against the crankcase housing assembly, and the other end of the torsion spring is connected to the second mounting hole. The torque of the torsion spring causes the positioning member to have a tendency to rotate the positioning roller toward the direction close to the four-star wheel, so that the positioning roller abuts against the reverse gear positioning groove, the neutral gear positioning groove, or the forward gear positioning groove.

[0015] The beneficial effects of this utility model are:

[0016] (1) This utility model only requires a shift control arm to transmit the externally applied circumferential rotational force to the transmission drum assembly. The shift control arm has a simple structure and occupies less space, thus making the layout of each component of the crankcase more compact, which is conducive to the miniaturization and weight reduction of the crankcase.

[0017] (2) The present invention is connected to the outer arm and the device for applying circumferential rotational force through the connecting part. The connection part and the outer arm are located at the accommodating arc groove, which can make full use of the space outside the crankcase cover.

[0018] (3) In the process of engine shifting, the positioning roller of the positioning component moves from one positioning groove of the gear shifting drum assembly to another positioning groove of the gear shifting drum assembly to achieve accurate positioning after shifting and prevent disengagement. Attached Figure Description

[0019] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the following drawings are provided for illustration:

[0020] Figure 1 This is one of the exploded schematic diagrams of this utility model;

[0021] Figure 2 This is a front view of the present invention;

[0022] Figure 3 This is a side view of the present invention;

[0023] Figure 4 This is the second exploded schematic diagram of this utility model;

[0024] Figure 5 This is a schematic diagram of the structure of the concealed crankcase cover of this utility model;

[0025] Figure 6 for Figure 5A magnified view of part A;

[0026] Figure 7 for Figure 5 Schematic diagram of the BB cross section;

[0027] Figure 8 for Figure 7 A magnified view of a portion at point C;

[0028] Figure 9 This is a schematic diagram of the structure of the gear shift drum assembly and the positioning component of this utility model.

[0029] Figure 10 This is a schematic diagram of the star wheel body of this utility model;

[0030] Figure 11 This is a schematic diagram of the gear shift control arm of this utility model;

[0031] Figure 12 This is a schematic diagram of the crankcase cover of this utility model;

[0032] Figure 13 This is a partial structural diagram of the shift control arm of this utility model, showing the outer arm extending outside the crankcase housing assembly.

[0033] The following labels are shown in the attached diagram:

[0034] 1-Crankcase housing assembly, 101-Crankcase body, 102-Crankcase cover, 1021-Allowing arc-shaped groove, 1022-Limiting contact surface;

[0035] 2-Transmission drum assembly, 201-Transmission drum body, 2011-Positioning pin, 202-Star wheel body, 2021-Sliding pin, 2022-Positioning hole, 2023-Reverse gear positioning groove, 2024-Neutral gear positioning groove, 2025-Forward gear positioning groove, 203-First bolt;

[0036] 3-Positioning assembly, 301-Positioning component, 3011-First mounting hole, 3012-Second mounting hole, 3013-Positioning roller, 302-Torsion spring, 303-Second bolt;

[0037] 4-Shift control arm, 401-Inner arm, 4011-First connecting section, 4012-Second connecting section, 4013-Third connecting section, 4014-Control handle, 4015-Slide groove, 4016-Limiting sector platform, 402-Outer arm, 4021-Spline section, 4022-Threaded section;

[0038] 5-Oil seal. Detailed Implementation

[0039] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0040] like Figures 1-13 As shown, an engine shifting structure in this embodiment includes a crankcase housing assembly 1, a transmission drum assembly 2, a positioning assembly 3, and a shift control arm 4. Rotation of the shift control arm 4 drives the transmission drum assembly 2 to rotate, thereby achieving gear shifting. The positioning assembly 3 prevents disengagement after gear shifting. The transmission drum assembly 2 is rotatably disposed within the crankcase housing assembly 1, and the transmission drum assembly 2 is provided with a sliding pin 2021. The shift control arm 4 includes an inner arm 401 and an outer arm 402. The inner arm 401 is rotatably disposed within the crankcase housing. Inside component 1, the outer arm 402 is connected to the inner arm 401, and the outer arm 402 extends to the outside of the crankcase housing assembly 1. The inner arm 401 is provided with a control handle 4014, and the control handle 4014 is provided with a sliding groove 4015. The length direction of the sliding groove 4015 is along the radial direction of the shift control arm 4. The sliding groove 4015 is slidably engaged with the sliding pin 2021. The rotation axis of the shift control arm 4, the rotation axis of the gear shift drum assembly 2, and the central axis of the sliding pin 2021 are not coincident and are parallel to each other.

[0041] The axis of rotation of the shift control arm 4 is Figure 7 and Figure 8 Line a in the diagram, the central axis of positioning hole 2022 is... Figure 7 and Figure 8 Line b in the diagram, the rotation axis of the gear shift drum assembly 2 is... Figure 7 and Figure 8 In the figure, line d, the central axis of sliding pin 2021 is Figure 7 and Figure 8 Line e in the middle.

[0042] The slide groove 4015 is an oblong groove, and its width matches the outer diameter of the slide pin 2021. Since the rotation axes of the shift control arm 4, the gear shift drum assembly 2, and the central axis of the slide pin 2021 are not coincident and are parallel to each other, when a circumferential rotational force is applied to the outer arm 402, the outer arm 402 drives the shift control arm 4 to rotate as a whole, the inner arm 401 and the control handle 4014 to rotate, the slide groove 4015 drives the slide pin 2021 to move, and the slide pin 2021 drives the gear shift drum assembly 2 to rotate around its rotation axis, thereby achieving engine shifting. While the slide pin 2021 rotates around its rotation axis, it simultaneously slides along the length of the slide groove 4015. Since only the shift control arm 4 is needed to transmit the externally applied circumferential rotational force to the transmission drum assembly 2, and the shift control arm 4 has a simple structure and occupies less space, the layout of the crankcase components is more compact, which is conducive to the miniaturization and weight reduction of the crankcase.

[0043] In this embodiment, the crankcase housing assembly 1 includes a crankcase body 101 and a crankcase cover 102 connected to the crankcase body 101. The crankcase cover 102 is provided with a clearance arc-shaped groove 1021 corresponding to the position of the outer arm 402.

[0044] The connecting part of the device for applying circumferential rotational force to the outer arm 402 is connected to the outer arm 402. The connection position of the connecting part to the outer arm 402 is at the relief arc groove 1021, which can make full use of the space outside the crankcase cover 102.

[0045] The crankcase 101 and the crankcase cover 102 are connected together by multiple bolts, so as to achieve a detachable connection between the crankcase 101 and the crankcase cover 102. During assembly, a sealing gasket can also be set between the crankcase 101 and the crankcase cover 102 to enhance the sealing performance and prevent internal lubricating oil leakage.

[0046] In this embodiment, the outer arm 402 includes a spline segment 4021 and a threaded segment 4022. The spline segment 4021 is connected to the inner arm 401, and the threaded segment 4022 is disposed on the side of the spline segment 4021 away from the inner arm 401.

[0047] The connecting part of the device for applying circumferential rotational force to the outer arm 402 is sleeved on the spline section 4021 and axially limited by the threaded section 4022. The connecting part and the spline section 4021 are connected by a spline groove pair, which enables the outer arm 402 to move through the connecting part. The threaded section 4022 can be prevented from separating from the outer arm 402 by installing a nut.

[0048] In this embodiment, the inner arm 401 includes a first connecting segment 4011, a second connecting segment 4012, and a third connecting segment 4013 connected in sequence. The first connecting segment 4011 is rotatably engaged with the crankcase 101. An oil seal 5 is provided between the third connecting segment 4013 and the crankcase cover 102. The operating handle 4014 is located at one end of the first connecting segment 4011 near the second connecting segment 4012.

[0049] The first connecting section 4011, the second connecting section 4012, the third connecting section 4013, the splined section 4021, and the threaded section 4022 are arranged sequentially along the axial direction of the shift control arm 4. The axes of the first connecting section 4011, the second connecting section 4012, the third connecting section 4013, the splined section 4021, and the threaded section 4022 coincide. The oil seal 5 provided between the third connecting section 4013 and the crankcase cover 102 can improve the sealing performance.

[0050] In this embodiment, a limiting sector 4016 is provided at one end of the second connecting segment 4012 near the first connecting segment 4011, and a limiting contact surface 1022 is provided on the crankcase cover 102 corresponding to the position of the limiting sector 4016.

[0051] The crankcase 101 is provided with an inner arm mounting hole for the insertion of the first connecting section 4011. The insertion of the first connecting section 4011 of the inner arm 401 into the inner arm mounting hole can limit the shift control arm 4 axially and radially. Furthermore, when the crankcase cover 102 is closed on the crankcase 101, the limiting contact surface 1022 is attached to the limiting sector 4016. The limiting contact surface 1022 is a plane perpendicular to the rotation axis of the shift control arm 4, which can limit the limiting sector 4016 axially without affecting the rotation of the limiting sector 4016, thereby ensuring the installation stability of the shift control arm 4.

[0052] The first connecting section 4011, the second connecting section 4012, the third connecting section 4013, the spline section 4021, and the threaded section 4022 are integrally formed machined structures. The operating handle 4014 and the limiting sector table 4016 are connected to the machined structure by welding.

[0053] In this embodiment, the gear shift drum assembly 2 includes a gear shift drum body 201 and a star wheel body 202 disposed at one end of the gear shift drum body 201. The middle part of the star wheel body 202 is connected to the gear shift drum body 201 by a first bolt 2026. The rotation of the star wheel body 202 can drive the gear shift drum body 201 to rotate.

[0054] In this embodiment, a positioning pin 2011 is provided on the gearbox body 201, and a positioning hole 2022 is provided on the star wheel body 202. The positioning pin 2011 is inserted into the positioning hole 2022 and the end of the positioning pin 2011 does not protrude from the positioning hole 2022.

[0055] The positioning pin 2011 and the positioning hole 2022 cooperate to ensure the accurate relative position of the gear drum body 201 and the star wheel body 202 during installation. The end of the positioning pin 2011 does not protrude from the positioning hole 2022 to prevent the positioning pin 2011 from interfering with the control handle 4014.

[0056] The positioning pin 2011 and the gear shift drum body 201 can be integrated as one piece, or the positioning pin 2011 can be inserted into the gear shift drum body 201 after the first insertion hole is set.

[0057] The sliding pin 2021 and the star wheel body 202 can be integrated, or the sliding pin 2021 can be inserted by setting a second socket on the star wheel body 202 and the gear shift drum body 201.

[0058] In this embodiment, the central axis of the first bolt 2026 coincides with the rotation axis of the gear shift drum assembly 2, and the central axis of the positioning hole 2022 coincides with the central axis of the positioning pin 2011; the rotation axis of the shift control arm 4, the central axis of the positioning hole 2022, the rotation axis of the gear shift drum assembly 2, and the central axis of the sliding pin 2021 are arranged sequentially in the vertical direction and are all parallel to each other.

[0059] In this embodiment, the star wheel body 202 is a four-star wheel. The outer contour of the star wheel body 202 is provided with a reverse gear positioning groove 2023, a neutral gear positioning groove 2024 and a forward gear positioning groove 2025. The neutral gear positioning groove 2024 is located between the reverse gear positioning groove 2023 and the forward gear positioning groove 2025.

[0060] In this embodiment, the positioning component 3 includes a positioning member 301 and a torsion spring 302. The first end of the positioning member 301 is provided with a first mounting hole 3011, and the tail end of the positioning member 301 is provided with a rotatable positioning roller 3013. The middle part of the positioning member 301 is provided with a second mounting hole 3012. The middle part of the torsion spring 302 and the first mounting hole 3011 are rotatably mounted to the crankcase housing assembly 1 by a second bolt 303. One end of the torsion spring 302 abuts against the crankcase housing assembly 1, and the other end of the torsion spring 302 is connected to the second mounting hole 3012. The torque of the torsion spring 302 causes the positioning member 301 to have a tendency to drive the positioning roller 3013 to rotate toward the four-star wheel, so that the positioning roller 3013 abuts against the reverse gear positioning groove 2023, the neutral gear positioning groove 2024, or the forward gear positioning groove 2025.

[0061] During engine gear shifting, the positioning roller 3013 of the positioning component 3 moves from one positioning groove of the gear shift drum assembly 2 to another positioning groove of the gear shift drum assembly 2 to achieve precise positioning after gear shifting and prevent gear slippage.

[0062] For example, if the initial gear shift drum assembly 2 is in neutral, the shift control arm 4 drives the gear shift drum assembly 2 to... Figure 5 and Figure 6 After rotating clockwise by a certain angle, the gear shift drum assembly 2 rotates from the neutral position to the forward gear position. During the rotation of the gear shift drum assembly 2, the torque of the torsion spring 302 causes the positioning roller 3013 to abut against the neutral positioning groove 2024 or the forward gear positioning groove 2025. The positioning roller 3013 of the positioning assembly 3 rolls along the neutral positioning groove 2024 to the forward gear positioning groove 2025, and finally abuts against the forward gear positioning groove 2025 to prevent disengagement. Conversely, if the gear shift drum assembly 2 is initially in the neutral position, the shift control arm 4 drives the gear shift drum assembly 2 to... Figure 5 and Figure 6 After rotating counterclockwise by a certain angle, the gear shift drum assembly 2 rotates from the neutral position to the reverse position. During the rotation of the gear shift drum assembly 2, the torque of the torsion spring 302 causes the positioning roller 3013 to abut against the neutral positioning groove 2024 or the reverse positioning groove 2023. The positioning roller 3013 of the positioning assembly 3 rolls along the neutral positioning groove 2024 to the reverse positioning groove 2023. The positioning roller 3013 of the positioning assembly 3 abuts against the reverse positioning groove 2023 to prevent disengagement.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An engine shifting structure, comprising a crankcase housing assembly, a transmission drum assembly, a positioning assembly, and a shift control arm, wherein rotation of the shift control arm can drive rotation of the transmission drum assembly to achieve gear shifting, and the positioning assembly is used to prevent disengagement after gear shifting, characterized in that: The shift drum assembly is rotatably disposed within the crankcase housing assembly, and the shift drum assembly is provided with a sliding pin; the shift control arm includes an inner arm and an outer arm, the inner arm is rotatably disposed inside the crankcase housing assembly, the outer arm is connected to the inner arm and extends to the outside of the crankcase housing assembly, the inner arm is provided with a control handle, the control handle is provided with a sliding groove, the length direction of the sliding groove is along the radial direction of the shift control arm, the sliding groove is slidably engaged with the sliding pin, and the rotation axis of the shift control arm, the rotation axis of the shift drum assembly and the central axis of the sliding pin are not coincident and are parallel to each other.

2. The engine shifting structure according to claim 1, characterized in that: The crankcase housing assembly includes a crankcase body and a crankcase cover connected to the crankcase body, and the crankcase cover is provided with a clearance arc-shaped groove corresponding to the position of the outer arm.

3. The engine shifting structure according to claim 1 or 2, characterized in that: The outer arm includes a splined section and a threaded section. The splined section is connected to the inner arm, and the threaded section is located on the side of the splined section away from the inner arm.

4. The engine shifting structure according to claim 2, characterized in that: The inner arm includes a first connecting section, a second connecting section, and a third connecting section connected in sequence. The first connecting section is rotatably engaged with the crankcase. An oil seal is provided between the third connecting section and the crankcase cover. The operating handle is located at one end of the first connecting section near the second connecting section.

5. The engine shifting structure according to claim 4, characterized in that: A limiting sector is provided at one end of the second connecting segment near the first connecting segment, and a limiting contact surface is provided on the crankcase cover corresponding to the position of the limiting sector.

6. The engine shifting structure according to claim 1, characterized in that: The gear shift drum assembly includes a gear shift drum body and a star wheel body disposed at one end of the gear shift drum body. The middle part of the star wheel body is connected to the gear shift drum body by a first bolt.

7. The engine shifting structure according to claim 6, characterized in that: The transmission drum body is provided with a positioning pin, and the star wheel body is provided with a positioning hole. The positioning pin is inserted into the positioning hole and the end of the positioning pin does not protrude from the positioning hole.

8. The engine shifting structure according to claim 7, characterized in that: The central axis of the first bolt coincides with the rotation axis of the gear shift drum assembly, and the central axis of the positioning hole coincides with the central axis of the positioning pin; the rotation axis of the shift control arm, the central axis of the positioning hole, the rotation axis of the gear shift drum assembly, and the central axis of the sliding pin are arranged sequentially in the vertical direction and are all parallel to each other.

9. The engine shifting structure according to claim 6, characterized in that: The star wheel body is a four-star wheel, and the outer contour of the star wheel body is provided with a reverse gear positioning groove, a neutral gear positioning groove and a forward gear positioning groove, with the neutral gear positioning groove located between the reverse gear positioning groove and the forward gear positioning groove.

10. The engine shifting structure according to claim 9, characterized in that: The positioning assembly includes a positioning member and a torsion spring. The first end of the positioning member is provided with a first mounting hole, the tail end of the positioning member is provided with a rotatable positioning roller, and the middle part of the positioning member is provided with a second mounting hole. The middle part of the torsion spring and the first mounting hole are rotatably mounted to the crankcase housing assembly by a second bolt. One end of the torsion spring abuts against the crankcase housing assembly, and the other end of the torsion spring is connected to the second mounting hole. The torque of the torsion spring causes the positioning member to have a tendency to rotate the positioning roller toward the direction close to the four-star wheel, so that the positioning roller abuts against the reverse gear positioning groove, the neutral gear positioning groove, or the forward gear positioning groove.

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