A double row engagement spring structure for a positive engagement starter

Abstract

The utility model discloses a kind of double-row engagement spring structures of forced engagement starter, to solve the technical problem that the single-row engagement spring of forced engagement starter in prior art is prone to compression too short when top tooth, energy storage is insufficient, leading to insufficient length that one-way gear enters flywheel gear ring, causes the technical problem of gear milling failure, including starter housing, electromagnetic switch, direct current motor and driving gear assembly;Electromagnetic switch and driving gear assembly are connected by double-row spring assembly;Direct current motor includes armature shaft;Driving gear assembly includes one-way clutch, inner tooth shaft and driving gear;Armature shaft and one-way clutch are engaged by inner tooth shaft;Electromagnetic switch includes switch shaft;Double-row spring assembly includes yoke, engagement spring group and spring seat;Engagement spring group includes first spring and second spring, both are arranged with same circle center and set along switch shaft linear motion direction;First spring and second spring one end are connected with yoke, the other end is connected with starter housing.

Description

Technical Field

[0001] This utility model relates to the field of automotive starter technology, and in particular to a double-row engagement spring structure for a forced engagement starter. Background Technology

[0002] The forced engagement starter is the most basic component in automotive electrical systems, mainly composed of a DC motor, a transmission engagement mechanism, and a switch. Existing forced engagement starters typically use a single-spring structure for the engagement spring, which stores energy through spring compression to drive the drive gear and flywheel ring gear. However, the single-spring structure has the following drawbacks: 1. The spring is prone to fatigue fracture under long-term high-frequency impact loads, leading to starter failure; 2. The fixed stiffness of a single spring cannot adapt to changes in engagement resistance under different operating conditions, potentially resulting in poor engagement or excessive impact; 3. The limited spring compression stroke makes it difficult to meet the engagement requirements of high-torque starters.

[0003] In traditional forced engagement starters, the single-row engagement spring is prone to excessive compression and insufficient energy storage when the gear is engaged, resulting in insufficient length of the one-way gear entering the flywheel ring gear and causing milling failure. Utility Model Content

[0004] The purpose of this invention is to provide a double-row engagement spring structure for a forced engagement starter to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A double-row engagement spring structure for a forced engagement starter includes a starter housing, an electromagnetic switch connected to the top of the starter housing, a DC motor connected to the lower part of the starter housing below the electromagnetic switch, a drive gear assembly connected to the lower part of the starter housing and coaxially arranged with the DC motor, and a double-row spring assembly; wherein the electromagnetic switch and the drive gear assembly are connected by the double-row spring assembly.

[0007] The DC motor includes an armature shaft that outputs driving force when energized.

[0008] The drive gear assembly includes a one-way clutch, an internal gear shaft, and a drive gear that meshes with the engine flywheel ring gear; the armature shaft is dynamically engaged with the one-way clutch via the internal gear shaft; the drive gear is connected to the one-way clutch.

[0009] The electromagnetic switch includes a switch shaft that moves linearly under the action of electromagnetic force after being energized.

[0010] The double-row spring assembly includes a shift fork, a meshing spring group, and a spring seat connected to the meshing spring group; the meshing spring group includes a first spring and a second spring; the first spring is sleeved outside the second spring and is concentrically arranged; a shift fork shaft is hinged to the middle of the shift fork; the top end of the shift fork is connected to the switch shaft, and the bottom end of the shift fork is hinged to a one-way clutch; both the first spring and the second spring are arranged along the linear movement direction of the switch shaft; the ends of both the first spring and the second spring near the shift fork are connected to the shift fork through the spring seat, and the ends of both the first spring and the second spring away from the shift fork are connected to the starter housing.

[0011] Preferably, both the first spring and the second spring have a shot-peened reinforcement layer on their surfaces to improve fatigue life.

[0012] Preferably, the spring seat includes a U-shaped seat body and a limiting post, the shift fork is hinged to the seat body of the spring seat through a shift fork shaft, and the first spring and the second spring are both limited and sleeved on the limiting post; the inner wall of the starter housing is provided with a guide groove that matches the seat body, and the groove structure ensures that there is no lateral displacement when the spring is compressed.

[0013] Preferably, the double-row spring assembly further includes a U-shaped guide block and a sealing buffer pad that match both the first spring and the second spring to reduce frictional loss with the housing; the guide block abuts against the end face of both the first spring and the second spring away from the shift fork, and the seat abuts against the end face of both the first spring and the second spring near the shift fork, providing spring support and guidance.

[0014] Working principle: During the operation of this forced engagement starter, when the electromagnetic switch coil is energized, the switch shaft pulls the shift fork under the action of electromagnetic force. With the shift fork shaft as the fulcrum, the shift fork pushes the drive gear against the engine's flywheel ring gear, resulting in two possible scenarios:

[0015] 1. Smooth engagement

[0016] The teeth of the drive gear are aligned with the grooves of the flywheel ring gear, and the drive gear meshes with the flywheel ring gear very easily. Then, the contacts at the rear of the electromagnetic switch are turned on, the DC motor is energized and rotates, and the engine is started.

[0017] 2. Forced engagement

[0018] When the teeth of the drive gear are aligned with the teeth of the flywheel ring gear, a tooth-over-tooth situation occurs, at which point the drive gear stops moving forward. However, due to the large electromagnetic force of the electromagnetic switch, the switch shaft continues to pull the fork, which compresses the engagement spring assembly. The two springs move synchronously through the guide mechanism, forming a staged energy storage and release. The movement of the fork fulcrum causes the switch shaft to continue moving until the electromagnetic switch contacts are closed, energizing the DC motor and causing it to rotate. When the drive gear rotates through a very small angle, it disengages from the tooth-over-tooth position. At this point, the engagement spring assembly buffers the impact and compensates for changes in meshing resistance, forcing the drive gear to engage with the flywheel ring gear.

[0019] Compared with the prior art, the double-row engagement spring structure of the forced engagement starter of this application has the following advantages:

[0020] 1. Staged energy storage and dynamic compensation: Through the synergistic action of a high-stiffness first spring and a low-stiffness second spring, staged energy storage and release are formed, reducing the peak load of a single spring. The first spring quickly absorbs the initial impact load, and the second spring then provides progressive buffering and compensates for changes in meshing resistance, effectively mitigating the impact vibration caused by sudden changes in meshing resistance.

[0021] 2. Fatigue life doubled design: The dual-spring parallel structure makes the stress distribution more uniform. Combined with the surface shot peening treatment, it still maintains an extremely low elastic modulus decay rate after high cycle and high load, which effectively improves the overall service life compared with the traditional single spring structure.

[0022] 3. Precision motion control system: The unique U-shaped seat spring seat and guide groove matching structure reduces the lateral offset of the spring compression stroke, while the sealed buffer pad realizes the axial motion damping adjustment, effectively reducing the meshing trajectory error of the drive gear.

[0023] 4. Improved dynamic meshing adaptability: The composite stiffness characteristics of the dual springs can be automatically adjusted with the meshing depth. When the meshing resistance reaches a certain threshold, the second spring enters the nonlinear deformation zone to absorb energy and achieve smooth meshing.

[0024] 5. Fault prevention improvements: By increasing the effective compression stroke and coordinating the precise fit between the limit pin and the guide block, the drive gear can maintain continuous meshing pressure with the flywheel ring gear even under top gear operation, thus reducing the milling failure rate.

[0025] This structure, through the collaboration of an innovative double-row spring dynamic model and a precision guidance system, effectively improves meshing efficiency and extends overall service life. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0027] Figure 2 This is a cross-sectional view of the structure of an embodiment of the present utility model;

[0028] Figure 3 This is a schematic diagram of the connection structure between the electromagnetic switch, DC motor, drive gear assembly and double-row spring assembly in an embodiment of this utility model;

[0029] Figure 4 This is a schematic diagram of the connection structure between the double-row spring assembly and the starter housing in an embodiment of this utility model;

[0030] Figure 5 This is an exploded view of the connection structure between the double-row spring assembly and the starter housing in an embodiment of this utility model;

[0031] Figure 6 This is a schematic diagram of the structure of the double-row spring assembly in an embodiment of this utility model;

[0032] Figure 7 This is an exploded view of the double-row spring assembly in an embodiment of this utility model.

[0033] Reference numerals: 1. Starter housing; 11. Guide groove; 2. Electromagnetic switch; 21. Switch shaft; 3. DC motor; 31. Armature shaft; 4. Drive gear assembly; 41. One-way clutch; 42. Internal gear shaft; 43. Drive gear; 5. Double-row spring assembly; 51. Shift fork; 511. Shift fork shaft; 52. Engagement spring assembly; 521. First spring; 522. Second spring; 53. Spring seat; 531. Sealing body; 532. Limiting post; 54. Guide block; 55. Sealing buffer pad. Detailed Implementation

[0034] The following detailed description illustrates the specific implementation method:

[0035] Example 1

[0036] like Figure 1-7 As shown, this embodiment illustrates a double-row engagement spring structure for a forced-engagement starter motor, including a starter motor housing 1, an electromagnetic switch 2 connected to the top of the starter motor housing 1, a DC motor 3 connected to the lower part of the starter motor housing 1 below the electromagnetic switch 2, a drive gear assembly 4 connected to the lower part of the starter motor housing 1 and coaxially arranged with the DC motor 3, and a double-row spring assembly 5; wherein, the electromagnetic switch 2 and the drive gear assembly 4 are connected by the double-row spring assembly 5. Specifically, the forced-engagement automotive starter motor is the most basic component in automotive electrical systems, responsible for converting electrical energy into mechanical energy to drive the engine flywheel to rotate and start the engine.

[0037] In this embodiment, the DC motor 3 includes an armature shaft 31 that outputs driving force after being energized, thereby starting the engine.

[0038] In this embodiment, the drive gear assembly 4 includes a one-way clutch 41, an internal gear shaft 42, and a drive gear 43 that can mesh with the engine flywheel ring gear; the armature shaft 31 and the one-way clutch 41 are dynamically engaged through the internal gear shaft 42; the drive gear 43 is connected to the one-way clutch 41.

[0039] In this embodiment, the electromagnetic switch 2 includes a switch shaft 21 that moves linearly under the action of electromagnetic force after being energized.

[0040] In this embodiment, the double-row spring assembly 5 includes a shift fork 51, a meshing spring group 52, and a spring seat 53 connected to the meshing spring group 52. The meshing spring group 52 includes a first spring 521 and a second spring 522. The first spring 521 is sleeved on the outside of the second spring 522 and is arranged concentrically. A shift fork shaft 511 is hinged to the middle of the shift fork 51. The top end of the shift fork 51 is connected to the switch shaft 21, and the bottom end of the shift fork 51 is hinged to the one-way clutch 41. The first spring 521 and the second spring 522 are arranged along the linear movement direction of the switch shaft 21. The ends of the first spring 521 and the second spring 522 near the shift fork 51 are connected to the shift fork 51 through the spring seat 53, and the ends of the first spring 521 and the second spring 522 away from the shift fork 51 are connected to the starter housing 1. To further explain, the parallel structure of the two springs makes the stress distribution more uniform. Through the synergistic effect of the high-stiffness first spring 521 and the low-stiffness second spring 522, a graded energy storage and release is formed, reducing the load peak of a single spring. The first spring 521 quickly absorbs the initial impact load, and the second spring 522 then provides progressive buffering and compensates for changes in meshing resistance, effectively mitigating the impact vibration caused by sudden changes in meshing resistance. The composite stiffness characteristics of the two springs can be automatically adjusted with the meshing depth. When the meshing resistance reaches a certain threshold, the second spring 522 enters the nonlinear deformation zone to absorb energy, achieving smooth meshing.

[0041] Operating instructions for a forced engagement starter:

[0042] When the coil of electromagnetic switch 2 is energized, the switch shaft 21 pulls the fork under the action of electromagnetic force. When the shift fork 51 uses the shift fork shaft 511 as a fulcrum to push the drive gear 43 towards the flywheel ring gear of the engine, two situations will occur:

[0043] 1. Smooth engagement

[0044] The teeth of the drive gear 43 are aligned with the groove of the flywheel ring gear, and the drive gear 43 meshes with the flywheel ring gear very easily. Then the contacts at the rear of the electromagnetic switch 2 are turned on, the DC motor 3 is energized and rotates, and the engine is started.

[0045] 2. Forced engagement

[0046] When the teeth of the drive gear 43 are aligned with the teeth of the flywheel ring gear, a tooth-over-tooth situation occurs, at which point the drive gear 43 stops moving forward. However, due to the large electromagnetic force of the electromagnetic switch 2, the switch shaft 21 continues to pull the fork 51, which compresses the engagement spring assembly 52. ​​The two springs move synchronously through the guide mechanism, forming a staged energy storage and release. The fulcrum of the fork 51 moves, causing the switch shaft 21 to continue moving until the contacts of the electromagnetic switch 2 are closed, and the DC motor 3 is energized and rotates. When the drive gear 43 rotates through a very small angle, it disengages from the tooth-over-tooth position. At this time, the engagement spring assembly 52 buffers the impact and compensates for the change in meshing resistance, causing the drive gear 43 to be forcibly engaged with the flywheel ring gear.

[0047] Example 2

[0048] like Figure 1-7 As shown, another embodiment, based on Embodiment 1, illustrates a double-row engagement spring structure for a forced engagement starter. Further, in a further possible implementation of this embodiment, both the first spring 521 and the second spring 522 have a shot-peened reinforcement layer on their surfaces. After surface shot-peening, the double springs maintain an extremely low elastic modulus decay rate even after high-cycle, high-load conditions, thus improving fatigue life. Further, in these embodiments, as... Figure 4-7 As shown, the spring seat 53 includes a U-shaped seat body 531 and a limiting post 532. The shift fork 51 is hinged to the seat body 531 of the spring seat 53 via a shift fork shaft 511. The first spring 521 and the second spring 522 are both limited and sleeved on the limiting post 532. The inner wall of the starter housing 1 is provided with a guide groove 11 that matches the seat body 531. The U-shaped seat body 531 and the spring seat 53 cooperate with the guide groove 11 to reduce the lateral offset when the spring is compressed.

[0049] Furthermore, in these embodiments, the double-row spring assembly 5 also includes a U-shaped guide block 54 and a sealing buffer pad 55 that match both the first spring 521 and the second spring 522, reducing frictional loss with the housing, achieving axial motion damping adjustment, and effectively reducing the meshing trajectory error of the drive gear 43. The guide block 54 abuts against the end face of both the first spring 521 and the second spring 522 away from the shift fork 51, and the seat 531 abuts against the end face of both the first spring 521 and the second spring 522 near the shift fork 51, providing spring support and guidance. Specifically, during forced engagement, the effective compression stroke is increased by the double springs, and with the precise fit between the limit post 532 and the guide block 54, it is ensured that the drive gear 43 can maintain continuous meshing pressure with the flywheel ring gear even under top gear operation, reducing the milling failure rate. The above descriptions are merely embodiments of this utility model, and common knowledge such as specific structures and characteristics in the solution are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications and improvements will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A double-row engagement spring structure for a forced engagement starter, characterized in that: The device includes a starter housing, an electromagnetic switch connected to the top of the starter housing, a DC motor connected to the lower part of the starter housing below the electromagnetic switch, a drive gear assembly and a double-row spring assembly connected to the lower part of the starter housing and coaxially arranged with the DC motor; wherein the electromagnetic switch and the drive gear assembly are connected by the double-row spring assembly. The DC motor includes an armature shaft that outputs driving force after being energized; The drive gear assembly includes a one-way clutch, an internal gear shaft, and a drive gear that meshes with the engine flywheel ring gear; the armature shaft is dynamically engaged with the one-way clutch via the internal gear shaft; the drive gear is connected to the one-way clutch. The electromagnetic switch includes a switch shaft that moves linearly under the action of electromagnetic force after being energized; The double-row spring assembly includes a shift fork, a meshing spring group, and a spring seat connected to the meshing spring group; the meshing spring group includes a first spring and a second spring; the first spring is sleeved outside the second spring and is concentrically arranged; a shift fork shaft is hinged to the middle of the shift fork; the top end of the shift fork is connected to the switch shaft, and the bottom end of the shift fork is hinged to a one-way clutch; both the first spring and the second spring are arranged along the linear movement direction of the switch shaft; the ends of both the first spring and the second spring near the shift fork are connected to the shift fork through the spring seat, and the ends of both the first spring and the second spring away from the shift fork are connected to the starter housing.

2. The double-row engagement spring structure for a forced engagement starter according to claim 1, characterized in that: Both the first spring and the second spring have a shot-peened layer on their surfaces.

3. The double-row engagement spring structure for a forced engagement starter according to claim 2, characterized in that: The spring seat includes a U-shaped seat body and a limiting post. The shift fork is hinged to the seat body of the spring seat through a shift fork shaft. The first spring and the second spring are both limited and sleeved on the limiting post. The inner wall of the starter housing is provided with a guide groove that matches the seat body.

4. The double-row engagement spring structure for a forced engagement starter according to claim 3, characterized in that: The double-row spring assembly also includes a U-shaped guide block and a sealing buffer pad that match both the first spring and the second spring; the guide block abuts against the end face of both the first spring and the second spring away from the shift fork, and the seat abuts against the end face of both the first spring and the second spring near the shift fork.

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