An engine starting clutch provided with a bidirectional starting cam

Abstract

The utility model provides a kind of engine starting clutch with bidirectional starting cam, including energy storage shaft, bidirectional starting cam and starting clutch, and starting clutch includes a pair of split type clutch support, for connecting between a pair of clutch support reset spring and the clutch piece for the adhesion starting cup being set on the outer wall of clutch support, a pair of clutch support is enclosed with the bidirectional groove adapted with bidirectional starting cam, and starting wall of a pair of clutch support is opened when energy release is set on bidirectional starting cam;The utility model is provided with bidirectional starting cam, clutch support and clutch piece, using bidirectional starting cam distal end variable diameter and abutting on clutch support, using energy storage shaft to drive bidirectional starting cam reverse, bidirectional starting cam flings clutch support to make clutch piece unfold and tightly adhere on starting cup inner wall, using friction force to drive starting cup high speed to realize engine starting, and the structure is simple and compact, light in weight, easy to operate, low in cost.

Description

Technical Field

[0001] This utility model belongs to the technical field of engine starting, and particularly relates to an engine starting clutch with a bidirectional starting cam. Background Technology

[0002] With the continuous development of the economy, the degree of agricultural mechanization is getting higher and higher, and agricultural tillage equipment is being used more and more widely. Its power source is basically an air-cooled engine. Before the air-cooled engine can be put into operation, it must be equipped with an auxiliary starting device. The auxiliary starting devices commonly used on the market are still the manual pull starting mode. The driver uses a crank to drive the starting mechanism on the auxiliary starting device to start it. The starting mechanism drives the energy storage shaft to rotate, which tightens the spring in the auxiliary starting device. Then, when the spring releases its tension, it generates explosive force to drive the starter cup on the air-cooled engine to rotate at high speed to start it.

[0003] Currently, both auxiliary starting devices and air-cooled engine starter cups utilize a clutch mechanism (which mainly includes a pawl seat and a starting pawl / starting pawl) for connection and disengagement. A common method of engagement between the clutch mechanism and the starter cup involves directly engaging the clutch mechanism and starter cup simultaneously with the release of the spiral spring. Specifically, when the spiral spring releases, it drives the pawl seat to rotate at high speed. The starting pawl, mounted on the pawl seat, is then thrown outwards at high speed and strikes the starting clutch, causing the starter cup to rotate at high speed to start the engine. A specific example is the air-cooled impact-resistant starting mechanism disclosed in patent application number 201310160572.1. However, the force exerted by the starting pawl during its outward throw is significant, causing a hard impact at the contact point between the starting pawl and the starter cup, resulting in deformation or even breakage, thus limiting its service life.

[0004] Another conventional way to coordinate the clutch mechanism and the starter cup is to first slightly release the spring force after the scroll spring is tightened, so that the energy storage shaft reverses at a small angle. This allows the starter pawl to be pre-inserted into the hole on the starter cup or locked onto the side wall of the starter cup. Then, the complete release of the scroll spring force drives the starter cup to rotate at high speed to achieve starting. This coordination method effectively solves the problem of short service life caused by hard impact between the starter pawl and the starter cup. Examples include the air-cooled engine starter disclosed in patent application number 201210450531.1, the air-cooled engine safety starter disclosed in patent application number 201310048731.9, the air-cooled engine pull-free starter disclosed in patent application number 201310278516.9, and the manual internal combustion engine starter disclosed in patent application number 201220611030.2.

[0005] In this clutch mechanism and starting cup cooperation method, the starting pawl opens outward by the outer end of the starting pawl abutting against one of the side walls of the outlet when the energy storage shaft reverses at a small angle, and retracts inward by the outer end of the starting pawl abutting against the other side wall of the outlet after starting. However, since conventional starting pawls are long and flat, in order to allow the starting pawl to open to a relatively large angle, the pawl opening must be set to be arc-shaped. This results in a relatively large distance between the two side walls of the pawl opening. After the outer end of the starting pawl retracts inward, it abuts against one side wall of the pawl opening. Therefore, before the starting pawl opens outward, it must first move along the pawl opening to abut against the other side wall of the pawl opening. This means that when the energy storage shaft reverses at a small angle, the starting pawl does not immediately open outward, but will have a pause period because it needs to move along the pawl opening. This results in the starting pawl taking too long to switch from the retracted state to the open state, i.e., the opening speed is too slow. At the same time, in order to prevent the spring force of the spiral spring from being released too much, resulting in a very short reversal distance of the energy storage shaft in this state, it often happens that the energy storage shaft has finished reversing before the starting pawl has fully opened, causing the starting pawl and the starting cup to fail to form an effective engagement.

[0006] Chinese Patent 201921916104.1 discloses an engine starting clutch, belonging to the field of mechanical technology. It solves the problem of short service life of existing auxiliary starting clutches. It includes an energy storage shaft, a pawl seat circumferentially fixed to the energy storage shaft, and a friction element that generates rotational resistance to the pawl seat. Several starting pawls are hinged to the pawl seat, distributed around the energy storage shaft and capable of swinging relative to the pawl seat. The friction element has several pawl outlets circumferentially on its side, with the outer end of each starting pawl located at its corresponding outlet. The friction element has a starting groove between each pair of adjacent pawl outlets. The inner end of each starting pawl protrudes radially and has a starting part located within the starting groove. Rotation of the energy storage shaft allows the starting part to abut against the groove wall. It features a long service life and efficient starting pawl operation. While offering advantages such as short start-up time and high success rate of engagement with the starter cup, this method, which uses friction components, starter claws, and starter grooves, places high demands on the machining precision of the grooves and starter claws. Often, due to wear, insufficient machining precision in the starter claws and starter grooves leads to excessive gaps between the starter claws and starter cups, resulting in one or two starter claws experiencing excessive force and deformation. Additionally, after only a few dozen uses, the friction components suffer severe wear on the outer surface of the spring box, forming deep scratches that cause loosening, leading to abnormal noises and starter claws failing to return to their proper positions. Installation is also relatively troublesome, requiring the installation of spring wave coils to control installation precision. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this utility model provides an engine starting clutch with a bidirectional starting cam. This clutch comprises a bidirectional starting cam, a clutch bracket, and clutch plates. The distal end of the bidirectional starting cam changes diameter and rests against the clutch bracket. An energy storage shaft drives the bidirectional starting cam to rotate in reverse, causing it to disengage from the clutch bracket and unfold the clutch plates, which then tightly adhere to the inner wall of the starting cup. Friction drives the starting cup to rotate at high speed, thus starting the engine. This structure is simple, compact, lightweight, easy to operate, and low in cost.

[0008] This utility model discloses an engine starting clutch with a bidirectional starting cam, comprising an energy storage shaft, a bidirectional starting cam fixed on the energy storage shaft, and a starting clutch fitted around the bidirectional starting cam. The starting clutch includes a pair of split clutch brackets, a return spring for connecting the pair of clutch brackets, and a clutch plate disposed on the outer wall of the clutch brackets for abutting the starting cup. A bidirectional groove adapted to the bidirectional starting cam is formed between the pair of clutch brackets. The two ends of the bidirectional starting cam away from the center are provided with starting walls that open the pair of clutch brackets when energy is released.

[0009] During operation, similar to the starter in the background technology, it first accumulates energy to drive the energy storage shaft to rotate at high speed. Then, the energy storage shaft reverses a short distance to open the starting clutch and engage with the starting cup on the engine. Finally, the accumulated energy is fully released to drive the starting cup to rotate at high speed to achieve starting. Specifically, when the energy storage shaft is accumulating energy, the bidirectional starting cam drives the starting clutch to rotate forward together, at which point the starting clutch is in the closed state. When the energy storage shaft has finished accumulating energy and reverses at a small angle, the energy storage shaft and the bidirectional starting cam rotate in the same direction. At this time, the starting clutch has a certain speed difference with the bidirectional starting cam under the action of gravity, causing the starting wall of the bidirectional starting cam to press against the clutch bracket, thus opening the starting clutch until the clutch plate unfolds and tightly adheres to the inner wall of the starting cup and engages with the starting cup. During starting, the friction between the clutch plate and the starting cup is used to make the energy storage shaft rotate the bidirectional starting cam, clutch plate, and starting cup together, and the accumulated energy is fully released to drive the starting cup to rotate at high speed to achieve starting.

[0010] In the aforementioned engine starter, the clutch plate includes an arc-shaped plate and a wear-resistant plate bonded to the outer wall of the arc-shaped plate. The clutch bracket is vertically disposed on the inner wall of the arc-shaped plate, and both ends of the arc-shaped plate are provided with connection holes for connection with a return spring near their ends.

[0011] In the aforementioned engine starter, the clutch bracket and the arc plate are configured as an integral molded body made of alloy compression molding.

[0012] In the aforementioned engine starter, both the clutch bracket and the arc plate are integrally formed by stamping alloy plates, and the clutch bracket and the arc plate are welded together.

[0013] In the aforementioned engine starter, the upper and lower surfaces of the starting clutch are respectively provided with an upper limit cover plate and a lower limit cover plate. The upper and lower limit cover plates are provided with through holes for the energy storage shaft to pass through in the middle. The upper limit cover plate is provided with a pair of symmetrically arranged connecting anchors near both ends. The lower limit cover plate is provided with corresponding rivet connecting holes for connecting anchors. The clutch bracket is provided with limiting grooves for connecting anchors to pass through near both ends.

[0014] In the aforementioned engine starter, the upper or lower limit cover is provided with a bent limit plate for blocking the reset spring.

[0015] In the aforementioned engine starter, the energy storage shaft is configured as a polygonal shaft near its end, the bidirectional starter cam has a polygonal hole in the middle that is adapted to the polygonal shaft, and the energy storage shaft has a retaining groove near the polygonal shaft for fixing the bidirectional starter cam.

[0016] In the aforementioned engine starter, the starting clutch is configured with a conical structure on its outer wall.

[0017] The beneficial effects of this utility model are as follows: This utility model relates to an engine starting clutch with a bidirectional starting cam. It consists of a bidirectional starting cam, a clutch bracket, and a clutch plate. The distal end of the bidirectional starting cam changes diameter and abuts against the clutch bracket. The energy storage shaft drives the bidirectional starting cam to rotate in reverse. The bidirectional starting cam then throws off the clutch bracket, causing the clutch plate to unfold and tightly adhere to the inner wall of the starting cup. Friction drives the starting cup to rotate at high speed to start the engine. This structure is simple, compact, lightweight, easy to operate, and low in cost. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the engine starting clutch with a bidirectional starting cam according to the present invention. Figure 2 This is a top view of the engine starting clutch with a bidirectional starting cam according to the present invention; Figure 3 This is a bottom view of the engine starting clutch with a bidirectional starting cam according to the present invention; Figure 4 This is a diagram showing the installation state of the starter bracket, bidirectional starter cam, and clutch disc in the engine starter clutch of this utility model. Figure 5This is a partially exploded view of the starter bracket, bidirectional starter cam, and clutch plate in the engine starter clutch of this utility model. Figure 6 This is an exploded view of the starter bracket, bidirectional starter cam, and clutch disc in the engine starter clutch of this utility model. Figure 7 This is an exploded schematic diagram of the starter bracket, bidirectional starter cam, and clutch disc in the engine starter clutch of this utility model; Figure 8 This is a schematic diagram of the bidirectional starting cam in the engine starting clutch of this utility model.

[0019] Reference numerals: 1-Main body; 2-Spring box; 3-Energy storage shaft; 4-Starting shaft; 5-Roll spring; 6-Driving gear; 7-Driven gear; 8-Ratchet; 9-Limit plate; 10-Starting clutch; 11-Bidirectional starting cam; 12-Clutch plate; 13-Reset spring; 14-Upper limit cover plate; 15-Connecting anchor; 16-Polygonal shaft; 17-Snap ring groove; 18-Polygonal hole; 19-Clutch bracket; 20-Arc plate; 21-Limit groove; 22-Lower limit cover plate; 23-Rivet connection hole; 24-Through hole; 25-Wear-resistant plate; 26-Bending limit plate; 27-Bidirectional groove; 28-Starting arm; 29-Connecting hole. Detailed Implementation

[0020] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0021] like Figures 1-8 The diagram shown is an optical path diagram of the engine starting clutch with a bidirectional starting cam according to the present invention. The engine starting clutch with a bidirectional starting cam according to the present invention includes an energy storage shaft 3, a bidirectional starting cam 11 fixed on the energy storage shaft 3, and a starting clutch 10 fitted around the bidirectional starting cam 11. The starting clutch 10 includes a pair of split clutch brackets 19, a return spring 13 for connecting the pair of clutch brackets 19, and a clutch plate 12 provided on the outer wall of the clutch brackets 19 for abutting the starting cup. A bidirectional groove 27 adapted to the bidirectional starting cam 11 is formed between the pair of clutch brackets 19. The two ends of the bidirectional starting cam 11 away from the center are provided with starting walls 28 that open the pair of clutch brackets 19 when releasing energy.

[0022] The auxiliary starter of the engine in this embodiment also includes a body 1, an energy storage shaft 3 located inside the body 1 and capable of rotation, the body 1 including a cover with one end open and the other end closed, and a spring box 2 fixed inside the cover, a spiral spring 5 disposed inside the spring box 2, one end of the outer edge of the spiral spring 5 being fixed to the spring box 2, the energy storage shaft 3 passing through the center of the spiral spring 5, and one end of the inner edge of the spiral spring 5 being connected to the energy storage shaft 3; one end of the starter shaft 4 is located inside the cover and connected to a drive gear 6, and one end of the energy storage shaft 3 extends out of the spring box 2 and is connected to a driven gear 7, the drive gear 6 and the driven gear 7 meshing; a ratchet 8 is sleeved on the end of the starter shaft 3 located outside the cover, and a stop plate assembly is hinged to the outside of the cover, the stop plate assembly being partially embedded in the teeth on the outer side of the ratchet 8. The ratchet 8 rotates in one direction. The starting shaft 4 is circumferentially fixed with a limiting piece 9, and a limiting head is fixed on the end face of the ratchet 7. The limiting piece 9 has a limiting notch on its outer edge. The limiting notch is arc-shaped, and when the limiting head is activated, the limiting head abuts against one side wall of the limiting notch, thus fixing the limiting piece 9 and the ratchet 8 circumferentially. In this way, the starting shaft 4 is circumferentially fixed with the ratchet 8, and the starting shaft 4 drives the ratchet 8 to rotate against the action of the stop plate assembly. When the spring force of the spiral spring 5 is tightened, the energy storage shaft 3 drives the starting shaft 4 to rotate in the opposite direction under the release of the spring force of the spiral spring 5. At this time, the ratchet 8 is locked by the stop plate assembly 9 and cannot move. Only when the user moves the stop plate assembly to unlock the ratchet 8 can the spring force of the spiral spring 5 be released so that the energy storage shaft 3 can rotate at high speed.

[0023] The bidirectional starting cam 11 and the starting clutch 10 are mounted on the other end of the extended spring box 2 of the energy storage shaft 3. During startup, the limiting head abuts against one side wall of the limiting notch, thereby fixing the limiting plate 9 and the ratchet 8 circumferentially. In this way, the starting shaft 4 is circumferentially fixed to the ratchet 8. The starting shaft 4 drives the ratchet 8 to rotate against the action of the stop plate assembly. When the spring force of the scroll spring 5 is tightened, the energy storage shaft 3 drives the starting shaft 4 to rotate in the opposite direction under the release of the spring force of the scroll spring 5. At this time, the ratchet 7 is locked by the stop plate assembly and remains stationary. Only when the user moves the stop plate assembly to unlock the ratchet 8 can the spring force of the scroll spring 5 be released so that the energy storage shaft 3, the bidirectional starting cam 11, and the starting clutch 10 can rotate at high speed.

[0024] As the energy storage shaft 3 and the bidirectional starting cam 11 reverse together, the starting wall 28 on the bidirectional starting cam 11 moves to the right and presses against the clutch bracket 19, so that the starting clutch 10 is in the open state, until the clutch plate unfolds and tightly adheres to the inner wall of the starting cup and engages with the starting cup. During startup, the energy storage shaft uses the friction between the clutch plate and the starting cup to rotate the bidirectional starting cam, the clutch plate and the starting cup together, and the accumulated energy is fully released to drive the starting cup to rotate at high speed to achieve startup.

[0025] In a preferred embodiment, the clutch plate 12 includes an arc-shaped plate 20 and a wear-resistant plate 25 bonded to the outer wall of the arc-shaped plate 20. The clutch bracket 19 is vertically disposed on the inner wall of the arc-shaped plate 20. Both ends of the arc-shaped plate 20 are provided with connection holes 29 connected to the return spring 13 near the end. In this embodiment, after the engine is started, the clutch bracket 19 is closed by the action of the return spring to reset, making it convenient for use during the next start.

[0026] In a preferred embodiment, the clutch bracket 18 and the arc plate 20 are integrally molded from alloy compression molding, and the clutch bracket 19 and the arc plate 20 are both integrally molded from alloy sheet stamping. The clutch bracket 19 and the arc plate 20 are welded together. In this embodiment, the clutch bracket 19 and the arc plate 20 are integrally molded in one piece, which reduces costs and facilitates processing. It is preferred to use aluminum alloy compression molding and powder alloy compression molding in one piece, which reduces costs while ensuring the strength of the starting clutch 10.

[0027] In a preferred embodiment, the upper and lower surfaces of the starting clutch 10 are respectively provided with an upper limit cover plate 14 and a lower limit cover plate 22. The upper limit cover plate 14 and the lower limit cover plate 22 are provided with through holes 24 for the energy storage shaft 3 to pass through. The upper limit cover plate 14 is provided with a pair of symmetrically arranged connecting anchors 15 near both ends. The lower limit cover plate 22 is provided with corresponding rivet connecting holes 23 for connecting anchors 15. The clutch bracket 19 is provided with limiting grooves 21 near both ends for connecting anchors 15 to pass through. In this embodiment, by providing the upper limit cover plate 14 and the lower limit cover plate 22, not only can the connection strength of the clutch be improved, but the size of the starting clutch can also be controlled by the movement of the connecting anchors 15 in the limiting grooves 21, and the resetting is also convenient.

[0028] In a preferred embodiment, the upper limit cover plate 14 or the lower limit cover plate 22 is provided with a bent limiting plate 26 for blocking the reset spring. The structure of this embodiment is conducive to the reset of the reset spring 13 and improves the service life of the reset spring 13.

[0029] In a preferred embodiment, the length of the limiting groove 21 is 5-6 mm larger than the diameter of the connecting anchor 15. In this embodiment, this structure ensures that the single-sided swing distance of the bidirectional starting cam 11 is within 5 mm, thus preventing excessive swing of the bidirectional starting cam 11 from causing excessive spring tension and resulting in spring failure.

[0030] In a preferred embodiment, the energy storage shaft 3 is configured as a polygonal shaft 16 near its end, and the bidirectional start-up cam is provided with a polygonal hole 18 in the middle that is adapted to the polygonal shaft. The energy storage shaft 3 is provided with a snap ring groove 17 for fixing the bidirectional start-up cam near the polygonal shaft. This structure is easy to process and assemble, and has low cost. The polygonal shaft 16 can be configured as a square shaft or a hexagonal shaft, and the corresponding polygonal hole 18 can be configured as a square hole or a hexagonal hole.

[0031] In a preferred embodiment, the starting clutch 10 is configured with a conical structure on its outer wall, with a taper of 3°. In this embodiment, the structure is conical on the inner wall of the starting cup. After the starting clutch 10 has been used 300-400 times, the surface of the starting clutch 10 will wear out. By adjusting the position of the starting clutch 10 inward by using shims, the starting clutch 10 can continue to be used, thereby extending the life of the starting clutch 10.

[0032] 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 starting clutch equipped with a bidirectional starting cam, characterized in that: The device includes an energy storage shaft (3), a bidirectional starting cam (11) fixed on the energy storage shaft (3), and a starting clutch (10) fitted around the bidirectional starting cam (11). The starting clutch (10) includes a pair of split clutch brackets (19), a return spring (13) for connecting the pair of clutch brackets (19), and a clutch plate provided on the outer wall of the clutch brackets (19) for abutting the starting cup. A bidirectional groove (27) adapted to the bidirectional starting cam (11) is formed between the pair of clutch brackets (19). The two ends of the bidirectional starting cam (11) away from the center are provided with starting walls (28) that open the pair of clutch brackets (19) when releasing energy.

2. An engine starting clutch with a bidirectional starting cam as described in claim 1, characterized in that: The clutch plate (12) includes an arc plate (20) and a wear-resistant plate (25) bonded to the outer wall of the arc plate (20). The clutch bracket (19) is vertically arranged on the inner wall of the arc plate (20). Both ends of the arc plate (20) are provided with connection holes (29) for connecting to the return spring (13).

3. An engine starting clutch with a bidirectional starting cam as described in claim 2, characterized in that: The clutch bracket (19) and the arc plate (20) are configured as an integral molded body made of alloy compression molding.

4. An engine starting clutch with a bidirectional starting cam as described in claim 2, characterized in that: Both the clutch bracket (19) and the arc plate (20) are integrally formed by stamping alloy plates, and the clutch bracket (19) and the arc plate (20) are welded together.

5. An engine starting clutch with a bidirectional starting cam as described in any one of claims 1 to 4, characterized in that: The upper and lower surfaces of the starting clutch (10) are respectively provided with an upper limit cover plate (14) and a lower limit cover plate (22). The upper limit cover plate (14) and the lower limit cover plate (22) are provided with through holes (24) for the energy storage shaft (3) to pass through. The upper limit cover plate (14) is provided with a pair of symmetrically arranged connecting anchors (15) near both ends. The lower limit cover plate (22) is provided with rivet connecting holes (23) corresponding to the connecting anchors (15). The clutch bracket (19) is provided with limiting grooves (21) near both ends for the connecting anchors (15) to pass through.

6. An engine starting clutch with a bidirectional starting cam as described in claim 5, characterized in that: The upper limit cover plate (14) or the lower limit cover plate (22) is provided with a bent limit plate (26) for blocking the reset spring.

7. An engine starting clutch with a bidirectional starting cam as described in claim 1, characterized in that: The energy storage shaft (3) is configured as a polygonal shaft (16) near its end. The bidirectional start-up cam is provided with a polygonal hole (18) in the middle that is adapted to the polygonal shaft (16). The energy storage shaft (3) is provided with a snap ring groove (17) for fixing the bidirectional start-up cam (11) near the polygonal shaft (16).

8. An engine starting clutch with a bidirectional starting cam as described in claim 1, characterized in that: The outer wall of the starting clutch (10) is provided with a conical structure.

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