JP7123506B2 - manual transmission - Google Patents

Description

The present invention relates to a manual transmission mounted on a vehicle such as an automobile.

A manual transmission (MT) is widely known as a transmission mounted on a vehicle such as an automobile.

A vehicle equipped with a manual transmission is provided with a shift lever in the interior of the vehicle. In a manual transmission, the meshing state of the gears is changed by a combination of the operation of the shift lever in the select direction (select operation) and the operation in the shift direction (shift operation), and the gear stage is configured according to the position of the shift lever. be done.

A manual transmission is provided with a reverse idler gear, for example, to constitute a reverse gear. The reverse idler gear is rotatably and axially movably supported on the reverse idler shaft. When the shift lever is in a position other than the reverse position, the reverse idler gear is arranged in a non-meshing position where the reverse idler gear does not mesh with both the reverse drive gear and the reverse driven gear. Then, when the shift lever is put into the reverse position, the reverse idler gear is moved from the non-engaging position to the meshing position where it meshes with both the reverse drive gear and the reverse driven gear. By meshing the reverse idler gear with both the reverse drive gear and the reverse driven gear, a reverse gear is configured in which power is transmitted from the input shaft to the output shaft via the reverse drive gear, the reverse idler gear and the reverse drive gear.

Japanese Utility Model Laid-Open No. 2-34849

In such a manual transmission, the reverse idler gear is precisely arranged in the meshing position and the non-engaging position so that the state in which the reverse idler gear meshes with both the reverse drive gear and the reverse driven gear and the state in which the reverse idler gear does not mesh are clearly distinguished. is preferred.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a manual transmission in which gears movably provided in the axial direction can be accurately positioned at their stop positions.

To achieve the above object, a manual transmission according to the present invention comprises a unit case, a shaft provided in the unit case and supported by the unit case, and a shaft supported rotatably and axially movably on the shaft. The unit case is formed with a bolt insertion hole extending in a direction perpendicular to the axial direction, and a wall portion is formed on the gear side of the bolt insertion hole. A bolt is inserted through the bolt insertion hole, and the bolt is inserted into a fixing hole formed in the shaft, thereby fixing the shaft to the unit case and securing strength around the bolt insertion hole. , and a stopper portion for restricting movement of the gear are formed as part of the wall portion in the orthogonal direction, and the stopper portion protrudes toward the gear with respect to the strength securing portion.

According to this configuration, the bolt is inserted from the outside of the unit case into the bolt insertion hole formed in the unit case, and the bolt is inserted into the fixing hole formed in the shaft, whereby the shaft is attached to the unit case. Fixed. A wall portion is formed in the unit case on the gear side with respect to the bolt insertion hole, and the wall portion includes a strength securing portion that secures strength around the bolt insertion hole and a stopper that restricts movement of the gear. part is formed.

The strength securing portion and the stopper portion are each formed as a part of the wall portion in the orthogonal direction, and the stopper portion protrudes toward the gear with respect to the strength securing portion. As a result, compared to a configuration in which the entire wall in the orthogonal direction is formed as a strength securing portion and a stopper, that is, a configuration in which the thickness of the wall in the axial direction is uniform, the position of the tip of the stopper is reduced. Accuracy can be easily ensured. Therefore, the gear is brought into contact with the tip of the stopper portion, and movement of the gear is restricted, so that the gear can be accurately positioned at the stop position.

Moreover, since the strength securing portion is recessed toward the bolt insertion hole side from the stopper portion, the gear can be prevented from coming into contact with the strength securing portion, and the movement of the gear can be prevented from being restricted by the strength securing portion.

In addition, since the thickness of the strength securing portion in the axial direction can be set to a thickness necessary and sufficient for securing strength, the strength securing portion is formed unnecessarily thick, resulting in waste of materials, an increase in weight, and a decrease in productivity ( Occurrence of blowholes) can be suppressed.

According to the present invention, the gear provided movably in the axial direction can be accurately arranged at the stop position.

1 is a cross-sectional view showing the configuration of a transmission unit according to one embodiment of the present invention; FIG. FIG. 4 is a cross-sectional view showing a configuration in the vicinity of a reverse idler shaft;

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Structure of transmission unit>
FIG. 1 is a sectional view showing the configuration of a transmission unit 1 provided with a differential case 61 according to one embodiment of the invention. In addition, in FIG. 1, the hatching representing the cross section is omitted.

The transmission unit 1 adopts the form of a transaxle having a transmission 3 and a differential gear 4 in a unit case 2 forming an outer shell of the transmission unit 1 . The transmission unit 1 is mounted on a vehicle using an engine (not shown) as a drive source, and the power of the engine is changed by the transmission 3, and the changed power is sent to the left and right driving wheels via the differential gear 4. introduce. Oil is sealed in the unit case 2 .

The transmission 3 is a manual transmission (MT) having five forward gears and one reverse gear, and is arranged on one side in the vehicle width direction with respect to the engine in the engine compartment of the vehicle. The transmission 3 includes an input shaft 11 extending in the vehicle width direction and an output shaft 12 arranged parallel to the input shaft 11 .

The engine-side end of the input shaft 11 passes through the unit case 2 and is connected to a clutch mechanism (not shown) outside the unit case 2 . The power of the engine is input to the input shaft 11 via a clutch mechanism. An engine-side end of the input shaft 11 in the unit case 2 is rotatably supported by the unit case 2 via a ball bearing 13 . On the other hand, the end of the input shaft 11 opposite to the engine side is rotatably supported by the unit case 2 via a ball bearing 14 .

A first-speed drive gear 21, a reverse drive gear 22, and a second-speed drive gear 23 are integrally formed on the input shaft 11 in order from the engine side. Further, on the input shaft 11, a 3rd speed drive gear 24, a 4th speed drive gear 25 and a 5th speed drive gear 26 are arranged in order from the 2nd speed drive gear 23 side on the side opposite to the engine side with respect to the 2nd speed drive gear 23. Each is supported so as to be relatively rotatable.

The engine-side end of the output shaft 12 is rotatably supported by the unit case 2 via a needle bearing 27 inside the unit case 2 . On the other hand, the end of the output shaft 12 opposite to the engine side is rotatably supported by the unit case 2 via a ball bearing 28 inside the unit case 2 .

An output gear 31 is integrally formed at the engine-side end of the output shaft 12 . A first-speed driven gear 32, a reverse driven gear 33, and a second-speed driven gear 34 are rotatably supported in order from the output gear 31 on the output shaft 12 on the opposite side of the output gear 31 from the engine side. ing. Furthermore, a third driven gear 35, a fourth driven gear 36, and a fifth driven gear 37 are spline-fitted to the output shaft 12 in order from the second driven gear 34 side on the side opposite to the engine side with respect to the second driven gear 34. It is supported so as not to rotate relative to it.

The 1st-speed driven gear 32 is always in mesh with the 1st-speed drive gear 21 , and the 2nd-speed driven gear 34 is always in mesh with the 2nd-speed drive gear 23 . In addition, the 3rd speed driven gear 35 is always meshed with the 3rd speed drive gear 24, the 4th speed driven gear 36 is always meshed with the 4th speed drive gear 25, and the 5th speed driven gear 37 is always meshed with the 5th speed drive gear 26. there is

A reverse idler shaft 41 is arranged in parallel with the input shaft 11 and the output shaft 12 in the unit case 2 . The engine-side end of the reverse idler shaft 41 is inserted into a recess 42 formed in the unit case 2 . A bolt insertion hole 43 is formed through the unit case 2 at a position opposed to the end of the reverse idler shaft 41 opposite to the engine side from above. A bolt 44 is inserted into the bolt insertion hole 43 from the outside of the unit case 2 . By screwing the tip of the bolt 44 into a fixing hole 45 formed in the reverse idler shaft 41 , the reverse idler shaft 41 is non-rotatably fixed to the unit case 2 .

A reverse idler gear 46 is supported on the reverse idler shaft 41 so as to be relatively rotatable and movable in the rotation axis direction. The reverse idler gear 46 is displaced between a meshing position where it meshes with both the reverse drive gear 22 and the reverse driven gear 33 and a non-engaging position where it disengages from the meshing with the reverse drive gear 22 and the reverse driven gear 33 .

A 1st-2nd speed synchromesh (hub assembly) 51 is provided between the 1st speed driven gear 32 and the 2nd speed driven gear 34 . The 1st-2nd speed synchromesh 51 has a known structure, and includes a synchronizer hub 52 spline-fitted to the output shaft 12, synchronizer rings 53 arranged on both sides of the synchronizer hub 52, and sleeves surrounding the outer periphery of the synchronizer hub 52. 54, etc. The inner peripheral surface of the sleeve 54 is spline-fitted with the outer peripheral surface of the synchro hub 52 , and the sleeve 54 rotates integrally with the synchro hub 52 and the output shaft 12 . The reverse driven gear 33 is formed integrally with the sleeve 54 .

A 3rd-4th speed synchromesh 55 is provided between the 3rd speed drive gear 24 and the 4th speed drive gear 25 . A fifth-speed synchromesh 56 is provided on the opposite side of the fifth-speed drive gear 26 from the engine side. Since the configurations of the 3rd-4th speed synchromesh 55 and the 5th speed synchromesh 56 are well known, the description thereof will be omitted.

When the shift lever is moved to the 1st speed position by the select operation and the shift operation of the shift lever provided in the vehicle compartment, the 1st speed driven gear 32 is shifted to the output shaft 12 by the function of the 1st-2nd speed synchromesh 51. are non-rotatably coupled to the As a result, power input to the input shaft 11 is transmitted to the output shaft 12 via the 1st speed drive gear 21 and the 1st speed driven gear 32 . At this time, the power of the engine is changed at the gear ratio of the first gear and transmitted to the output shaft 12 .

When the shift lever is moved to the 2nd speed position, the 1st-2nd speed synchromesh 51 functions to couple the 2nd speed driven gear 34 to the output shaft 12 so as not to rotate relative to it. As a result, power input to the input shaft 11 is transmitted to the output shaft 12 via the 2nd speed drive gear 23 and the 2nd speed driven gear 34 . At this time, the power of the engine is changed at the gear ratio of the second gear and transmitted to the output shaft 12 .

When the shift lever is moved to the 3rd speed position, the 3rd-4th speed synchromesh 55 functions to couple the 3rd speed drive gear 24 to the input shaft 11 so as not to rotate relative to it. As a result, the power input to the input shaft 11 is transmitted to the output shaft 12 via the 3rd speed drive gear 24 and the 3rd speed driven gear 35 . At this time, the power of the engine is changed at the gear ratio of the third speed stage and transmitted to the output shaft 12 .

When the shift lever is moved to the 4th speed position, the 3rd-4th speed synchromesh 55 functions to couple the 4th speed drive gear 25 to the input shaft 11 so as not to rotate relative to it. As a result, power input to the input shaft 11 is transmitted to the output shaft 12 via the 4th speed drive gear 25 and the 4th speed driven gear 36 . At this time, the power of the engine is shifted at the gear ratio of the fourth speed stage and transmitted to the output shaft 12 .

When the shift lever is set to the fifth speed position, the fifth speed synchromesh 56 functions to couple the fifth speed drive gear 26 to the input shaft 11 so as not to rotate relative to it. As a result, power input to the input shaft 11 is transmitted to the output shaft 12 via the fifth speed drive gear 26 and the fifth speed driven gear 37 . At this time, the power of the engine is shifted at the gear ratio of the fifth gear and transmitted to the output shaft 12 .

When the shift lever is placed in the reverse position, the shift and select shaft moves in the axial direction and the circumferential direction along with the select operation and shift operation of the shift lever, and the reverse shift fork moves, thereby rotating the reverse idler gear 46. It is displaced to a position where it meshes with the reverse drive gear 22 and the reverse driven gear 33 . At this time, the power input to the input shaft 11 is transmitted to the output shaft 12 via the reverse drive gear 22 , the reverse idler gear 46 and the reverse driven gear 33 . As a result, the output shaft 12 rotates in a direction opposite to that in the 1st-5th gear.

The differential gear 4 has a differential case 61 . The differential case 61 has a gear housing portion 63 that provides a gear housing space 62 inside, and a flange portion 64 that protrudes from the outer periphery of the gear housing portion 63 in the radial direction of rotation.

A pinion shaft 65 extending in the radial direction of rotation is held in the gear housing portion 63 so as to pass through the gear housing space 62 . Two pinion gears 66 and 67 are rotatably held on the pinion shaft 65 with a space therebetween. Two side gears 68 and 69 are arranged separately on both sides of the pinion shaft 65 in the gear housing space 62 . Both the side gears 68, 69 and the pinion gears 66, 67 are bevel gears, and each side gear 68, 69 meshes with both the pinion gears 66, 67.

The gear housing portion 63 is formed with cylindrical shaft insertion portions 71 and 72 penetrating in the direction in which the side gears 68 and 69 face each other, in other words, in the direction orthogonal to the pinion shaft 65 . Drive shafts (not shown) are inserted into the shaft insertion portions 71 and 72 from the outside of the differential case 61 . The tip of the drive shaft is coupled to side gears 68 and 69 in the gear housing space 62 so as not to rotate relative to each other.

Bearings 73 and 74 are fitted onto the shaft insertion portions 71 and 72, respectively. Outer races (outer rings) of the bearings 73 and 74 are non-rotatably held by the unit case 2 . Thereby, the differential case 61 is rotatably supported by the unit case via bearings 73 and 74 about the same rotation axis as the drive shaft.

A ring gear 75 is fixed to the flange portion 64 . The ring gear 75 integrally has a substantially annular plate-shaped web 76 surrounding the differential case 61 and a substantially cylindrical rim 77 surrounding the outer periphery of the web 76 . The rim 77 protrudes from the web 76 to both sides in the direction along the rotation axis of the differential case 61 . Gear teeth are formed on the outer peripheral surface of the rim 77 and mesh with the output gear 31 of the transmission 3 .

Power transmitted to the output shaft 12 of the transmission 3 is transmitted from the output gear 31 to the ring gear 75 . As a result, the ring gear 75 and the differential case 61 rotate together. Rotation of the differential case 61 is converted to rotation of side gears 68 and 69 via pinion gears 66 and 67 . As a result, the drive shaft rotates integrally with the side gears 68 and 69, and the rotation of the drive shaft is transmitted to the driving wheels of the vehicle.

In addition, since oil is sealed in the unit case 2, when the ring gear 75 and the differential case 61 rotate together, the oil accumulated at the bottom of the unit case 2 is scraped up by the ring gear 75 and the differential case 61 and splashes. As a result, oil droplets are supplied to each part in the unit case 2 .

<Main part configuration>
FIG. 2 is a cross-sectional view showing the configuration in the vicinity of the reverse idler shaft 41. As shown in FIG. Also in FIG. 2, the hatching representing the cross section is omitted.

A wall portion 81 is formed in the unit case 2 on the reverse idler gear 46 side with respect to the bolt insertion hole 43 . The wall portion 81 has a strength securing portion 82 securing strength around the bolt insertion hole 43 and a stopper portion 83 restricting the movement of the reverse idler gear 46 .

The strength securing portion 82 is formed above the stopper portion 83 as part of the wall portion 81 in the vertical direction, and includes a central portion 84 having a uniform thickness in the axial direction of the reverse idler shaft 41 and It includes an upper portion 85 and a lower portion 86 whose thickness increases as they are separated vertically. The thickness of the central portion 84 is designed to be a thickness capable of ensuring strength such that cracks do not occur around the bolt insertion hole 43 .

The stopper portion 83 is formed as a part of the wall portion 81 in the vertical direction below the strength securing portion 82 and has a block shape that protrudes from the strength securing portion 82 toward the reverse idler gear 46 . A tip surface 87 of the stopper portion 83 is formed on a plane perpendicular to the axial direction of the reverse idler shaft 41 .

When the reverse idler gear 46 is moved toward the stopper portion 83 , it abuts against the tip surface 87 of the stopper portion 83 , thereby restricting further movement of the reverse drive gear 22 and the reverse driven gear 33 . is placed in a non-meshing position where it does not mesh with the Further, when the reverse idler gear 46 is moved to the side opposite to the stopper portion 83 side, i.e., to the engine side, the reverse idler gear 46 contacts the unit case 2 via a washer 88 externally fitted on the reverse idler shaft 41, thereby preventing further movement. movement is regulated, and is arranged at a non-meshing position where it meshes with both the reverse drive gear 22 and the reverse driven gear 33 .

<Effect>
As described above, the bolt 44 is inserted from the outside of the unit case 2 into the bolt insertion hole 43 formed in the unit case 2, and the bolt 44 is inserted into the fixing hole 45 formed in the reverse idler shaft 41. , the reverse idler shaft 41 is fixed to the unit case 2 . A wall portion 81 is formed in the unit case 2 on the side of the reverse idler gear 46 with respect to the bolt insertion hole 43 , and the wall portion 81 includes a strength securing portion 82 that secures strength around the bolt insertion hole 43 . and a stopper portion 83 for restricting movement of the reverse idler gear 46 are formed.

The strength securing portion 82 and the stopper portion 83 are each formed as a part of the wall portion 81 in the orthogonal direction, and the stopper portion 83 protrudes toward the reverse idler gear 46 with respect to the strength securing portion 82 . As a result, compared to a configuration in which the entire orthogonal direction of the wall portion 81 is formed as the strength securing portion 82 and the stopper portion 83, that is, a configuration in which the thickness of the wall portion 81 in the axial direction is uniform, the stopper portion Positional accuracy of the tip surface 87 of 83 can be easily ensured. As a result, the reverse idler gear 46 abuts against the distal end surface 87 of the stopper portion 83, restricting the movement of the reverse idler gear 46, so that the reverse idler gear 46 can be accurately arranged at the non-meshing position.

Moreover, since the strength securing portion 82 is recessed closer to the bolt insertion hole 43 than the stopper portion 83 , the reverse idler gear 46 can be prevented from coming into contact with the strength securing portion 82 . It is possible to prevent restrictions on movement.

Further, since the thickness of the strength securing portion 82 in the direction of the line of the reverse idler shaft 41 can be set to a thickness necessary and sufficient for securing the strength, the strength securing portion 82 is formed unnecessarily thick, resulting in waste of materials and an increase in weight. And it is possible to suppress the decrease in productivity (the occurrence of blowholes).

<Modification>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, the reverse idler shaft 41 and the reverse idler gear 46 are taken up as examples of shafts and gears, respectively, but the present invention may be applied to configurations including other shafts and gears.

In addition, various design changes can be made to the above configuration within the scope of the matters described in the claims.

2: Unit case 3: Transmission 41: Reverse idler shaft (shaft)
43: Bolt insertion hole 44: Bolt 45: Fixing hole 46: Reverse idler gear (gear)
81: Wall portion 82: Strength securing portion 83: Stopper portion

Claims (1)

unit case and
a shaft provided in the unit case and supported by the unit case;
a gear rotatably and axially movably supported on the shaft;
The unit case is formed with a bolt insertion hole extending in a direction orthogonal to the axial direction, and a wall portion is formed on the gear side of the bolt insertion hole,
A bolt is inserted through the bolt insertion hole from the outside of the unit case, and the bolt is inserted into a fixing hole formed in the shaft, thereby fixing the shaft to the unit case,
a strength securing portion that secures strength around the bolt insertion hole and a stopper portion that restricts movement of the gear are formed as part of the wall portion in the orthogonal direction,
The stopper portion is formed on the shaft side with respect to the strength securing portion and protrudes toward the gear with respect to the strength securing portion ,
The gear has an inclined surface at an end portion of the outer peripheral portion on the wall portion side that is inclined away from the wall portion as it approaches the outer peripheral end,
The strength securing portion includes a central portion and an upper portion formed on the side opposite to the stopper portion with respect to the central portion,
The upper portion faces the inclined surface in the axial direction and is inclined so as to be positioned closer to the gear as the distance from the central portion increases,
A manual transmission, wherein a connection portion between the upper portion and a surface of the unit case facing the gear in the orthogonal direction is positioned closer to the gear than the stopper portion .

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