CN113187893A

CN113187893A - Speed change mechanism and gearbox

Info

Publication number: CN113187893A
Application number: CN202110465152.9A
Authority: CN
Inventors: 周涛; 陈夏冬; 周良兵; 洪莉; 周裕林; 姜荣
Original assignee: Chongqing Longxin Tonghang Engine Manufacturing Co ltd
Current assignee: Chongqing Longxin Tonghang Engine Manufacturing Co ltd
Priority date: 2021-04-23
Filing date: 2021-04-23
Publication date: 2021-07-30
Anticipated expiration: 2041-04-23
Also published as: CN113187893B

Abstract

The invention discloses a speed change mechanism which comprises a shifting fork and a guide head, wherein the shifting fork can axially and relatively slide, the shifting fork is provided with an engaging part I engaged with a molded line groove on a speed change drum, and the guide head is provided with an engaging part II engaged with another molded line groove on the speed change drum. According to the invention, through arranging the two engaging parts and matching with the two line grooves on the speed change drum, forced gear shifting in the gear shifting process can be realized, so that timely gear shifting is ensured, the gear-shifting problem caused by unsuccessful gear shifting is avoided, the gear rigidity is ensured to be effectively withdrawn, and the gear-shifting risk is avoided.

Description

Speed change mechanism and gearbox

Technical Field

The invention relates to the technical field of gearboxes, in particular to a speed change mechanism and a gearbox.

Background

In the existing shifting fork assembly, a shifting fork is connected with a guide head through a cylindrical pin, the cylindrical pin is in interference connection with the shifting fork, the guide head slides on the cylindrical pin, and meanwhile, the guide head slides in a variable speed drum-shaped wire slot to realize gear shifting; however, another gear of the same profile is difficult to be shifted, so that the situation that the gear shift is failed or not in place when the gear is shifted from the gear to an adjacent gear is caused, and at the moment, the gear-shifting risk exists in the shifting process, so that the gear breakage is easily caused;

disclosure of Invention

In view of this, the invention provides a speed change mechanism and a gearbox, which can ensure that the rigidity of the gear can be effectively withdrawn when the gear is withdrawn, and avoid the risk of gear shifting.

The speed change mechanism comprises a shifting fork and a guide head, wherein the shifting fork can axially and relatively slide, the shifting fork is provided with an engaging part I engaged with a molded line groove on a speed change drum, and the guide head is provided with an engaging part II engaged with another molded line groove on the speed change drum. In the gear shifting process, the speed changing drum can forcibly make the synchronizer I withdraw from the corresponding gear through the driving engagement part I, so that timely gear withdrawing is ensured, the gear taking problem caused by unsuccessful gear withdrawing is avoided, the gear rigidity is ensured to be effectively withdrawn, and the gear taking risk is avoided.

Further, still include variable speed drum and elastic component, the last molded lines groove I that is used for with the I meshing of meshing portion and the molded lines groove II that is used for with the II meshing of meshing portion that have of variable speed drum, the crooked main first grade groove section that forms of the II interior both sides walls of molded lines groove to the homonymy, the position that circumference corresponds to main first grade groove section on the molded lines groove I is provided with a grade of buffer groove section, the lateral wall that a grade of buffer groove section is close to molded lines groove II is synchronous to the incurve, keeps away from the lateral wall of molded lines groove II and keeps the linear type with a grade groove section, the elastic component has the gliding elastic force of messenger's shift fork axial direction head side. The structure can enable the first synchronizer to be elastically pressed on the first gear when starting, and the first synchronizer is automatically meshed with the first gear when the first gear rotates, so that the problem that the first gear is difficult to be engaged when a vehicle starts is solved.

Furthermore, the device also comprises a guide pipe, and the shifting fork and the guide head are axially sleeved on the guide pipe in a sliding manner. The guide tube is arranged to facilitate the formation of guide for the shifting fork and the guide head, the degree of association between the shifting fork and the guide head is improved, and the compactness of the whole structure is improved.

Furthermore, guide holes are coaxially formed in the shifting fork and the guide head, and guide columns are sleeved in the guide holes in an axially sliding mode. The sliding precision of the shifting fork and the guide sleeve is improved through the guide post, and meanwhile, the relative rotation between the shifting fork and the guide head is limited.

Furthermore, axial positioning pieces are arranged at two ends of the guide pipe, the shifting fork, the guide head and the elastic piece are positioned between the two axial positioning pieces, and the elastic piece is positioned between the shifting fork and one of the axial positioning pieces and has elastic force for enabling the shifting fork to slide towards the axial direction of the guide head. The two axial positioning pieces can limit the sliding stroke of the shifting fork and the guide head, and can provide support for the elastic piece, so that the elastic piece keeps the elastic force acting on the shifting fork.

Furthermore, one end of the guide pipe protrudes outwards in the radial direction to form a positioning ring to form an axial positioning piece, and the other end of the guide pipe is provided with a retaining ring to form another axial positioning piece. The axial positioning piece of the structure is beneficial to the installation and the disassembly of each part.

Furthermore, the adjusting device also comprises an adjusting gasket, and the adjusting gasket is arranged between the elastic piece and the axial positioning piece adjacent to the elastic piece. The thicker the adjusting gasket is, the greater the compression degree of the elastic part is, the greater the elastic force of the elastic part on the shifting fork is, and the faster and more reliable the gear combination is.

Furthermore, the shifting fork comprises a sliding guide sleeve, the sliding guide sleeve is sleeved on the guide pipe in a sliding mode, one end, close to the elastic piece, of the sliding guide sleeve is a stepped shaft section with a large outer part and a small inner part, and the elastic piece is sleeved on the small-diameter section of the stepped shaft section and abuts against the shaft shoulder. Do benefit to the installation of elastic component through this structure, but wherein elastic component and the minor diameter section interference fit of stepped shaft section to do benefit to the fixed of elastic component right-hand member portion.

The invention also provides a gearbox, and the gearbox is provided with the speed change mechanism.

The invention has the beneficial effects that:

according to the invention, by arranging the two engaging parts and matching the two profile slots on the speed change drum, forced gear shifting in the gear shifting process can be realized, so that timely gear shifting is ensured, the gear shifting problem caused by unsuccessful gear shifting is avoided, the gear rigidity is ensured to be effectively withdrawn, and the gear shifting risk is avoided; and the differentiation is realized on the two profile grooves on the speed-changing drum through the main first-gear profile groove section and the buffering first-gear profile groove section, so that the first synchronizer is elastically pressed on the first-gear when the first gear is started and engaged, and the first synchronizer is automatically engaged with the first-gear when the first-gear rotates, thereby solving the problem that the first gear is difficult to engage when the vehicle is started.

Drawings

The invention is further described below with reference to the figures and examples.

FIG. 1 is a schematic diagram of a conventional shifting mechanism with a third gear-reversing structure;

FIG. 2 is a schematic diagram of a prior art gearshift mechanism with four shift gears;

FIG. 3 is a schematic structural view of the shifting mechanism of the present invention;

FIG. 4 is a schematic view of the distribution structure of the variable speed drum type wire chase;

FIG. 5 is a schematic illustration of a neutral configuration;

FIG. 6 is a schematic diagram of a third gear shift;

FIG. 7 is a schematic view of a third gear-reversing structure;

FIG. 8 is a schematic diagram of a fourth gear shift;

FIG. 9 is a schematic view of a first-gear shift;

Detailed Description

Referring to fig. 1 and 2, a conventional shifting mechanism is shown, in which only a guide head of a first shift fork 1 'is engaged with a shift drum 2', that is, the shift drum is in a single-slot structure, and a first synchronizer 3 'is engaged with a third gear 4' in fig. 1, when a third gear is shifted to a fourth gear, the first synchronizer 3 'is first required to exit the third gear, then a second synchronizer 5' is engaged with a fourth gear 6 ', when the shift drum rotates, the first shift fork 1' and the second shift fork 7 'are driven to operate, the first shift fork 1' is driven to move rightward to drive the first synchronizer 3 'to move rightward to exit the third gear 4', but since only the guide head of the first shift fork 1 'is engaged with the shift drum 2', as shown in fig. 1, the shift drum drives a guide head of the first shift fork to slide rightward relative to the shift fork, and since a gear load is applied to the shift fork, the shift fork is not actually driven to slide rightward, in the process, the first synchronizer 3 ' is not actually driven to exit the third gear 4 ', and the first synchronizer 3 ' and the third gear 4 ' are also in a meshed state along with the continuous rotation of the shift drum as shown in fig. 2, the second shifting fork 7 ' is driven to operate to drive the second synchronizer 5 ' to be meshed with the fourth gear 6 ', so that the conditions of gear shift failure or gear shift failure are easy to occur, and at the moment, the gear shifting risk exists in the gear exiting process, and the gear breaking phenomenon is easy to cause.

The embodiment provides a speed change mechanism, which comprises a shifting fork 1 and a guide head 2, wherein the shifting fork can axially slide relative to the guide head, the shifting fork is provided with an engaging part I1 a engaged with a molded line groove on a speed change drum, and the guide head is provided with an engaging part II 2a engaged with another molded line groove on the speed change drum. Referring to fig. 3, the guide head is of a sleeve structure, the guide head and the shifting fork are coaxially arranged and can axially slide relative to each other, and referring to fig. 5, the speed change mechanism is applied to a gearbox and comprises a first gear 12, a second gear 13, a third gear 14, a fourth gear 15, a first synchronizer 16 and a second synchronizer 17, wherein the first synchronizer is located between the first gear 12 and the third gear 14, the second synchronizer is located between the second gear 13 and the fourth gear 15, the first synchronizer is connected with the first shifting fork 18, and the second synchronizer is connected with the second shifting fork 19; this speed change mechanism's a shift fork has two meshing portions of meshing portion I1 a and meshing portion II 2a, it is double-groove structure to correspond to a shift fork on the corresponding variable speed drum, two wire casings mesh respectively with two meshing portions respectively, at the gear shift in-process, for example in withdrawing from third gear and getting into the fourth gear in-process, the variable speed drum is through the meshing portion I1 a of driving a shift fork, force and make a synchronizer withdraw from third gear, and then guarantee in time withdrawing the shelves, avoid withdrawing the tape shelves problem that the shelves unsuccessful caused, guarantee the effectual withdraw of gear rigidity, stop the tape shelves risk.

In this embodiment, still include variable speed drum 3 and elastic component 8, the last molded lines groove I4 that is used for with meshing portion I1 a meshing and the molded lines groove II 5 that is used for with meshing portion II 2a meshing that have of variable speed drum, the crooked main first grade type groove section 5a that forms of both sides wall to the homonymy in the molded lines groove II 5, the position that circumference corresponds to main first grade type groove section 5a on the molded lines groove I4 is provided with buffering first grade type groove section 4a, the lateral wall that buffering first grade type groove section 4a is close to molded lines groove II 5 is synchronous outwardly directed bending with first grade type groove section 5a, keeps the linear type with the lateral wall of keeping away from molded lines groove II 5, elastic component 8 has the gliding elastic force of messenger's shift fork 18 axial to guide 2 side.

Referring to fig. 3 and 4, the elastic member is a cylindrical coil spring, but other known elastic structures may also be adopted, and the shift drum is provided with four strip-shaped wire slots, wherein two wire slots located at the rightmost side are a wire slot i 4 and a wire slot ii 5, the two wire slots are matched with a first shifting fork, the wire slot i 4 and the wire slot ii 5 are only distinguished at a main first-gear slot section 5a and a buffer first-gear slot section 4a, and the rest parts have the same structure;

the whole shifting process is described with reference to fig. 5 to 8, wherein fig. 5 is a neutral state, fig. 5 to 6 show a third gear state, in which the shift drum drives the first fork to slide leftward, so that the first synchronizer is engaged with the third gear, fig. 6 to 8 show a fourth gear process, wherein, fig. 6 to 7 show the third gear withdrawing process, fig. 7 to 8 show the fourth gear engaging process, as shown in fig. 7, the shift drum drives the first fork to slide to the right, at this time, the second slot ii 5 drives the second engaging portion ii 2a to slide to the right, at the same time, the profile groove I4 drives the meshing part I1 a to slide rightwards at the same time, so that the first shifting fork 18 is driven to slide rightwards rigidly, and the first synchronizer is forced to exit from the third gear, as shown in figure 8, when the first synchronizer completely exits from the third gear, the speed changing drum drives the second shifting fork to slide rightwards, and then the second synchronizer is driven to be meshed with the fourth gear; the structure forces the synchronizer I to timely withdraw from the third gear, so that timely gear withdrawal is ensured, the gear-shifting problem caused by unsuccessful gear withdrawal is avoided, the gear rigidity is ensured to be effectively withdrawn, and the gear-shifting risk is avoided;

referring to fig. 9, in a neutral starting state of first gear, when the first synchronizer is driven to slide rightwards to engage with the first gear, since each gear is in a static state in the starting state, the pin shaft of the first synchronizer may not correspond to the pin hole of the first gear axially, and at this time the first synchronizer cannot engage with the first gear, referring to fig. 4 and 9, when the engaging portion ii 2a slides to the section of the main first gear groove section 5a to drive the guide head to slide rightwards, the engaging portion i 1a slides to the section of the buffering first gear groove section 4a, since the linear side wall of the buffering first gear groove section 4a makes the engaging portion i 1a not driven by rigid right, and since the elastic member has an elastic force driving the first shift fork 18 to slide rightwards, the pin shaft of the synchronizer can elastically abut against the end of the first gear and the first shift fork 18 and the guide head 2 are not engaged, at this time the first shift fork 18 and the guide head 2 are axially far away from each other, when the starting is carried out to engage the forward gear, each gear rotates, and when a pin shaft hole on the first gear is aligned with a pin shaft of the first synchronizer during the rotation of the first gear, the first synchronizer slides rightwards under the elastic force to be meshed with the first gear; the structure can enable the first synchronizer to be elastically pressed on the first gear when starting, and the first synchronizer is automatically meshed with the first gear when the first gear rotates, so that the problem that the first gear is difficult to be engaged when a vehicle starts is solved.

In the embodiment, the device further comprises a guide pipe 6, and the shifting fork 1 and the guide head 2 are axially sleeved on the guide pipe in a sliding manner. In this embodiment, the pipe is the hollow circular tube structure, certainly also can be for realizing the tubular structure of pipe or other cross sectional shapes, and specific no longer giving details, do benefit to through the setting of pipe and form the direction to shift fork and direction head to improve the degree of association of the two, improve the compactness of whole structure.

In this embodiment, guide holes are coaxially formed in the shifting fork 1 and the guide head 2, and guide posts 7 are axially sleeved in the guide holes in a sliding manner. The guide post is in interference fit with the guide hole in the shifting fork, the guide post is in axial sliding fit with the guide hole in the guide head, the sliding precision of the shifting fork and the guide sleeve is improved through the guide post, and meanwhile, the relative rotation between the shifting fork and the guide head is limited.

In this embodiment, the two ends of the conduit 6 are provided with axial positioning parts, the shifting fork 1, the guide head 2 and the elastic part 8 are located between the two axial positioning parts, and the elastic part 8 is located between the shifting fork and one of the axial positioning parts and has elastic force for enabling the shifting fork to slide axially to the guide head 2 side. Combine the figure to show, two axial positioning pieces can restrict the slip stroke of shift fork and direction head, can provide the support for the elastic component moreover for the elastic component keeps acting on the elastic force on the shift fork, combine figure 9 in addition to show, when the direction head slides right, drive the pipe and slide right, the elastic component was compressed this moment, improves the elastic force that acts on shift fork 1, when a grade gear rotates, do benefit to the drive shift fork and slide right and then make a synchronous ware and a grade gear engagement.

In this embodiment, one end of the guide tube 6 protrudes radially outward to form a positioning ring 9 to form an axial positioning member, and the other end of the guide tube is provided with a retaining ring 10 to form another axial positioning member. The positioning ring is integrally formed on the guide pipe, the check ring is an elastic check ring, a clamping groove for mounting the check ring is formed in the excircle of the left end of the guide pipe, and the axial positioning piece with the structure is favorable for mounting and dismounting each component.

In this embodiment, the adjusting device further includes an adjusting washer 11, and the adjusting washer is disposed between the elastic member 8 and the axial positioning member adjacent to the elastic member. The adjusting gasket 11 is used for adjusting the maximum axial distance between the retainer ring 10 and the shifting fork 1 so as to adjust the compression degree of the elastic part; the thicker the adjusting washer 11, the greater the compression of the elastic element, the greater the elastic force of the elastic element on the fork, and the faster and more reliable the gear engagement.

In this embodiment, the shifting fork includes a sliding guide sleeve 1b, the sliding guide sleeve is slidably sleeved on the guide tube, one end of the sliding guide sleeve, which is close to the elastic element, is a stepped shaft section with a large outer part and a small inner part, and the elastic element is sleeved on a small diameter section of the stepped shaft section and abuts against a shaft shoulder. As shown in the attached drawings, the structure is favorable for installation of the elastic part, wherein the elastic part can be in interference fit with the small-diameter section of the stepped shaft section so as to be favorable for fixing the right end part of the elastic part.

The present embodiment also provides a transmission equipped with a variator according to any one of claims 1 to 7. Of course, the gearbox also comprises various parts such as gear shifting gears and the like, which belong to the prior art and are not described again;

finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.

Claims

1. A speed change mechanism characterized by: the shifting fork is provided with an engaging part I engaged with a molded line groove on the speed changing drum, and the guide head is provided with an engaging part II engaged with another molded line groove on the speed changing drum.

2. The variator of claim 1, wherein: still include variable speed drum and elastic component, have on the variable speed drum be used for with the I meshing of meshing portion type wire casing I and be used for with the II meshing of meshing portion type wire casing II, II interior both sides walls of wire casing form main a grade groove section to the homonymy bending, the position that circumference corresponds to main a grade groove section on the wire casing I is provided with a grade groove section of buffering, the lateral wall that a grade groove section of buffering is close to type wire casing II keeps the linear type with the lateral wall that a grade groove section is synchronous to the incurve, keeps away from type wire casing II, the elastic component has the gliding elastic force of messenger's shift fork axial to guide head side.

3. The variator of claim 2, wherein: the shifting fork and the guide head are axially sleeved on the guide pipe in a sliding manner.

4. The variator of claim 2, wherein: the shifting fork and the guide head are coaxially provided with guide holes, and guide columns are sleeved in the guide holes in an axially sliding manner.

5. The variator of claim 3, wherein: the catheter is characterized in that axial positioning pieces are arranged at two ends of the catheter, the shifting fork, the guide head and the elastic piece are located between the two axial positioning pieces, and the elastic piece is located between the shifting fork and one of the axial positioning pieces and has elastic force for enabling the shifting fork to slide towards the guide head in the axial direction.

6. The variator of claim 5, wherein: one end of the guide pipe protrudes outwards in the radial direction to form a positioning ring to form an axial positioning piece, and the other end of the guide pipe is provided with a check ring to form another axial positioning piece.

7. The variator of claim 5, wherein: still include adjusting shim, adjusting shim sets up between elastic component and rather than adjacent axial positioning piece.

8. The variator of claim 5, wherein: the shifting fork comprises a sliding guide sleeve, the sliding guide sleeve is sleeved on the guide pipe in a sliding mode, one end, close to the elastic piece, of the sliding guide sleeve is a stepped shaft section with a large outer part and a small inner part, and the elastic piece is sleeved on the small-diameter section of the stepped shaft section and abuts against the shaft shoulder.

9. A transmission, characterized by: the gearbox is provided with a gear shifting mechanism according to any one of claims 1 to 8.