JP2014035024A - Transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission for enabling gear shifting during reverse without adding a component to increase a shaft length.SOLUTION: The transmission includes a first input shaft 1 to which the revolution of an engine is selectively input, a second input shaft 2, and an output shaft 3 to which the revolution after gear shifting is output. During reverse, the rotation of the first input shaft 1 is reversed by a reverse idle gear mechanism R and transmitted to the second input shaft 2, and then a plurality of driven gears 2Dn (2b, 4b, 6b) inserted through the output shaft 3 are rotated in the opposite direction to that during forward travel. A selector mechanism S selects one of the second driven gears 2Dn (2b, 4b, 6b) to be fixed to the output shaft 3 in a relatively non-rotatable manner, thus enabling gear shifting during reverse. Since the selector mechanism S also functions as a shift mechanism during forward travel, the gear shifting during reverse can be performed without adding a component to increase a shaft length.

Description

  The present invention relates to a transmission capable of shifting during reverse.

  A transmission for an automobile normally has one gear ratio at the time of reverse. However, if the gear can be shifted at the time of reverse, there is an advantage that the climbing force at the time of reverse travel of the vehicle can be increased. Conventionally, as a vehicle transmission capable of shifting at the time of reverse, a switching mechanism used for reverse shifting is provided between a plurality of gears provided on the output shaft of the transmission, and the switching mechanism is switched along the output shaft. There is known one that performs a shift at the time of reverse (Patent Document 1).

Japanese Patent Laid-Open No. 62-274136

  However, if the output shaft housed in the transmission mission case is additionally provided with a switching mechanism used for reverse gear shifting, the shaft length of the output shaft will be increased correspondingly, so the transmission can be increased in size and Weight increase is inevitable.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission capable of shifting at the time of reverse without adding a part having a long shaft length.

  In order to achieve the above object, a first invention has a first input shaft and a second input shaft to which engine rotation is selectively input, and an output shaft to which rotation after shifting is output. A transmission, a first drive gear fixed to the first input shaft, a plurality of second drive gears having different numbers of teeth fixed to the second input shaft, and rotatably inserted into the output shaft, A first driven gear meshing with one drive gear, a plurality of second driven gears rotatably inserted in the output shaft and meshing with the second drive gear, and an output shaft by selecting one of these second driven gears And a selection mechanism for fixing the first input shaft to the second drive gear so as to be relatively non-rotatable. The second input shaft is reversely rotated by rotating the first input shaft. A transmission which is characterized in that a reverse idle gear mechanism for transmitting the bets.

  The second invention is a transmission having a first input shaft and a second input shaft to which rotation of an engine is selectively inputted, and an output shaft from which rotation after shifting is outputted, A first drive gear fixed to the input shaft, a plurality of second drive gears having different numbers of teeth that are rotatably inserted into the second input shaft, and a first drive gear that is rotatably inserted into the output shaft and meshes with the first drive gear The first driven gear, the plurality of second driven gears fixed to the output shaft and meshing with the second drive gear, and the second drive gear are selected and fixed to the second input shaft so as not to rotate relative to each other. Reverse idle that is interposed between the first driven gear and the second drive gear and reverses the rotation of the first input shaft and transmits it to the second input shaft. A transmission which is characterized in that a Ya mechanism.

  In these transmissions, the reverse idle gear mechanism includes a first reverse idle gear meshed with the first driven gear, a second reverse idle gear meshed with one of the second drive gears, and a first reverse idle gear. There may be provided a switching mechanism for switching between the state in which the rotation is transmitted to the second reverse idle gear and the state in which the rotation is not transmitted.

  In these transmissions, the first drive gear is composed of a plurality of odd speed gears or even speed gears, and the second drive gear is a plurality of even speed gears when the first drive gear is an odd speed gear. When the first drive gear is an even-numbered transmission gear, it may be composed of a plurality of odd-numbered transmission gears.

  In these transmissions, the first reverse idle gear is meshed with the lowest gear among the plurality of gears forming the first drive gear, and the second reverse idle gear is the plurality of gears forming the second drive gear. May be meshed with the highest gear.

  In these transmissions, the second input shaft may be a hollow shaft, and the first input shaft may be inserted therein so as to be relatively rotatable.

  According to the transmission of the present invention, at the time of reverse, the rotation of the first input shaft is reversed by the reverse idle gear mechanism and transmitted to the second input shaft, and the plurality of second driven gears inserted through the output shaft move forward. Rotate counterclockwise. Therefore, the selection mechanism selects any one of these second driven gears and fixes them to the output shaft so that they cannot be rotated relative to each other, thereby enabling a shift during reverse. Since this selection mechanism also serves as a transmission mechanism during forward movement, it is possible to realize a transmission that can perform a shift during reverse without adding a component that increases the shaft length.

It is explanatory drawing which shows typically the transmission for motor vehicles which concerns on one Embodiment of this invention. It is explanatory drawing which shows the time of normal reverse of the said transmission. It is explanatory drawing which shows the time of the extra reverse (gear ratio lower than normal reverse) of the said transmission. It is explanatory drawing which shows the time of high speed reverse (gear ratio higher than normal reverse) of the said transmission.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(First input shaft 1, second input shaft 2)
FIG. 1 schematically shows an automobile transmission M according to an embodiment of the present invention. In FIG. 1, the alternate long and short dash line indicates the signal flow. The transmission M according to this embodiment includes a first input shaft 1 and a second input shaft 2 that are pivotally supported by bearings on a transmission case. The second input shaft 2 is a hollow shaft, and the first input shaft 1 is inserted concentrically therethrough so as to be relatively rotatable. The first input shaft 1 has a protruding portion 1x protruding from the end portion of the second input shaft 2. The first input shaft 1 and the second input shaft 2 are each connected to a rotating shaft (crankshaft) of the engine via a clutch, and the rotation of the engine can be selectively input.

(Output shaft 3)
The transmission M has an output shaft 3 for outputting rotation after shifting. The output shaft 3 is pivotally supported by a bearing on the transmission case in parallel with the first input shaft 1 and the second input shaft 2, and is connected to driving wheels of an automobile (vehicle). As will be described in detail later, when the vehicle advances, the rotation of the engine is transmitted to the output shaft 3 via one of the first input shaft 1 and the second input shaft 2, and the output shaft 3 advances the drive wheels. Rotate to. On the other hand, when the vehicle moves backward, the rotation of the engine is transmitted to the output shaft 3 via the first input shaft 1, a reverse idle gear mechanism R, which will be described later, and the second input shaft 2, and the output shaft 3 is in a direction opposite to that when the vehicle is moving forward. Rotate in the direction to drive the drive wheel backward.

(First drive gear 1Dv)
The transmission M has a first drive gear 1Dv provided on the protruding portion 1x of the first input shaft 1. The first drive gear 1Dv is composed of an odd speed transmission gear fixed to the protrusion 1x of the first input shaft 1 so as not to be relatively rotatable. In the present embodiment, the first speed drive gear 1a, the third speed drive gear 3a, and the fifth speed. It is comprised from the drive gear 5a. The number of first drive gears 1Dv is not limited to three and may be one or more.

(Second drive gear 2Dv)
The transmission M has a plurality of second drive gears 2Dv provided on the second input shaft 2 and having different numbers of teeth. The second drive gear 2Dv is composed of a plurality of even-speed transmission gears fixed to the second input shaft 2 so as not to be relatively rotatable. In the present embodiment, the second-speed drive gear 2a, the fourth-speed drive gear 4a, and the sixth-speed drive gear. 6a. The number of second drive gears 2Dv is not limited to three and may be two or more. In contrast to this embodiment, an even-numbered transmission gear may be provided on the protruding portion 1x of the first input shaft 1 and an odd-numbered transmission gear may be provided on the second input shaft 2.

(First driven gear 1Dn)
The transmission M has a first driven gear 1Dn inserted through the output shaft 3 so as to mesh with the first drive gear 1Dv. The first driven gear 1Dn is engaged with the first speed drive gear 1a, the third speed drive gear 3a, and the fifth speed drive gear 5a constituting the first drive gear 1Dv, respectively, the first speed driven gear 1b, the third speed driven gear 3b, and the fifth speed driven gear 5b. It is composed of The first speed driven gear 1b, the third speed driven gear 3b, and the fifth speed driven gear 5b are rotatably inserted into the output shaft 3, respectively.

(Second driven gear 2Dn)
The transmission M has a second driven gear 2Dn inserted through the output shaft 3 so as to mesh with the second drive gear 2Dv. The second driven gear 2Dn is in mesh with the second speed drive gear 2a, the fourth speed drive gear 4a, and the sixth speed drive gear 6a constituting the second drive gear 2Dv, respectively, the second speed driven gear 2b, the fourth speed driven gear 4b, and the sixth speed driven gear 6b. It is composed of The second speed driven gear 2b, the fourth speed driven gear 4b, and the sixth speed driven gear 6b are rotatably inserted into the output shaft 3, respectively.

(Selection mechanism S)
The transmission M is a selection mechanism for selecting any one of the second speed driven gear 2b, the fourth speed driven gear 4b, and the sixth speed driven gear 6b constituting the second driven gear 2Dn and fixing the second driven gear 2Dn to the output shaft 3 in a relatively non-rotatable manner. S. The selection mechanism S is provided on the output shaft 3 between the first selection mechanism S1 provided on the output shaft 3 between the second speed driven gear 2b and the fourth speed driven gear 4b, and on the output shaft 3 between the sixth speed driven gear 6b and the first speed driven gear 1b. Second selection mechanism S2. As will be described later, the first selection mechanism S1 and the second selection mechanism S2 serve as both a speed change mechanism for the reverse travel of the vehicle and a speed change mechanism for the forward travel, and the second selection mechanism S2 includes the first driven gear when the vehicle moves forward. It is also possible to fix 1b to the output shaft 3 so as not to be relatively rotatable.

  The first selection mechanism S1 includes a hub 71 fixed to the output shaft 3 between the second-speed driven gear 2b and the fourth-speed driven gear 4b so as not to rotate relative to the hub 71. And a sleeve 81 engaged so as not to be relatively rotatable. On the outer peripheral surface of the sleeve 81, an engaging groove with which the shift fork 91 is engaged is formed along the circumferential direction. The shift fork 91 is operated in parallel with the axial direction of the output shaft 3 by an actuator (electric cylinder or the like) 101. As a result, the sleeve 81 moves along the axial direction of the output shaft 3 while being engaged with the hub 71.

  When the sleeve 81 is moved to the side of the fourth speed driven gear 4b, the sleeve 81 engages with the fourth speed driven gear 4b and rotates integrally therewith. On the other hand, when the sleeve 81 is moved to the second speed driven gear 2b side, the sleeve 81 engages with the second speed driven gear 2b and rotates integrally therewith. Thereby, the shift is achieved as described later. A synchromesh mechanism (synchronization mechanism) is preferably provided between the sleeve 81 and the fourth speed driven gear 4b and between the sleeve 81 and the second speed driven gear 2b.

  The second selection mechanism S2 has the same configuration as the first selection mechanism S1, and includes a hub 72 fixed to the output shaft 3 between the sixth speed driven gear 6b and the first speed driven gear 1b so as not to be relatively rotatable, And a sleeve 82 engaged with a spline or the like so as to be movable in the axial direction and not rotatable relative to the circumferential direction. On the outer peripheral surface of the sleeve 82, an engaging groove with which the shift fork 92 is engaged is formed along the circumferential direction. The shift fork 92 is operated by the actuator 102 in parallel with the axial direction of the output shaft 3.

  The sleeve 82 engages with the sixth speed driven gear 6b when moved to the sixth speed driven gear 6b side, and engages with the first speed driven gear 1b when moved to the first speed driven gear 1b side. Thereby, the shift is achieved as described later. A synchromesh mechanism is preferably provided between the sleeve 82 and the sixth speed driven gear 6b, and between the sleeve 82 and the first speed driven gear 1b.

  The actuator 101 of the first selection mechanism S1 and the actuator 102 of the second selection mechanism S2 are connected to an electronic control unit (hereinafter referred to as ECU) 10 and move the sleeves 81 and 82 based on a command from the ECU 10. The ECU 10 is connected to a shift device 11 provided in the driver's cab of the vehicle. A manual shift function for giving a shift command to the actuators 101 and 102 based on an operation of the shift device 11 by the driver, an engine operating state, and the vehicle It has an automatic speed change function that gives a speed change command to the actuators 101 and 102 in accordance with the running state.

(Transmission mechanism H)
The output shaft 3 is provided with a speed change mechanism H between the third speed driven gear 3b and the fifth speed driven gear 5b. As will be described later, the speed change mechanism H is a speed change mechanism dedicated to forward travel of the vehicle and is not used during reverse travel. The speed change mechanism H has the same configuration as the first selection mechanism S1 and the second selection mechanism S2 described above, and moves in the axial direction by a spline or the like to the hub 73 fixed to the output shaft 3 so as not to rotate relative to the output shaft 3. And a sleeve 83 engaged freely and circumferentially incapable of relative rotation. An engagement groove with which the shift fork 93 is engaged is formed on the outer peripheral surface of the sleeve 83, and the shift fork 93 is operated in parallel with the axial direction of the output shaft 3 by the actuator 103.

  The sleeve 83 engages with the third speed driven gear 3b when moved to the third speed driven gear 3b side, and engages with the fifth speed driven gear 5b when moved to the fifth speed driven gear 5b side. Thereby, the shift is achieved as described later. A synchromesh mechanism is preferably provided between the sleeve 83 and the third speed driven gear 3b and between the sleeve 83 and the fifth speed driven gear 5b.

  The actuator 103 of the transmission mechanism H is connected to the ECU 10. The actuator 103 operates the shift fork 93 of the speed change mechanism H based on a command from the ECU 10. The ECU 10 has a manual shift function for giving a shift command to the actuator 103 based on the operation of the shift device 11 by the driver, and an automatic shift function for giving a shift command to the actuator 103 according to the engine operating state and the vehicle running state.

(Reverse idle gear mechanism R)
The transmission M has a reverse idle gear mechanism R that reverses the rotation of the first input shaft 1 and transmits it to the second input shaft 2. The reverse idle gear mechanism R is interposed between the first driven gear 1b and the second drive gear 6a. The reverse idle gear mechanism R includes a first reverse idle gear 1r meshed with a first speed driven gear 1b constituting the first driven gear 1Dn and a second reverse meshed with a sixth speed drive gear 6a constituting a second drive gear 2Dv. An idle gear 2r and a switching mechanism K for switching between a state where the rotation of the first reverse idle gear 1r is transmitted to the second reverse idle gear 2r and a state where the rotation is not transmitted are provided.

  The 1st reverse idle gear 1r is being fixed to the reverse idle shaft 4 pivotally supported by the mission case by the bearing so that relative rotation is impossible. The reverse idle shaft 4 is disposed in parallel with the first input shaft 1 and the second input shaft 2. The second reverse idle gear 2r is rotatably inserted into the reverse idle shaft 4. The switching mechanism K includes a hub 74 that is fixed to the reverse idle shaft 4 so as not to be relatively rotatable, and a sleeve 84 that is engaged with the hub 74 by a spline or the like so as to be movable in the axial direction but not relatively rotatable in the circumferential direction. An engagement groove is formed in the outer circumferential surface of the sleeve 84 along the circumferential direction, and a shift fork 94 is engaged with the engagement groove. The shift fork 94 is operated by the actuator 104 in parallel with the axial direction of the reverse idle shaft 4. As a result, the sleeve 84 moves along the axial direction of the reverse idle shaft 4 while being engaged with the hub 74.

  When the sleeve 84 of the switching mechanism K is moved toward the second reverse idle gear 2r, the sleeve 84 engages with the second reverse idle gear 2r. Thus, the rotation of the first reverse idle gear 1r is transmitted to the second reverse idle gear 2r, and the rotation of the first input shaft 1 is reversed and transmitted to the second input shaft 2 (reverse state). On the other hand, when the sleeve 84 is moved in a direction away from the second reverse idle gear 2r, the sleeve 84 is detached from the second reverse idle gear 2r. Thereby, the rotation of the first reverse idle gear 1r is not transmitted to the second reverse idle gear 2r, and the rotation of the first input shaft 1 and the rotation of the second input shaft 2 are separated (reverse release). State). By switching between the reverse state and the reverse release state, switching between forward and reverse is achieved. A synchromesh mechanism is preferably provided between the sleeve 84 and the second reverse idle gear 2r.

  The actuator 104 of the switching mechanism K is connected to the ECU 10 and operates the shift fork 94 based on a command from the ECU 10. The ECU 10 gives a command to the actuator 104 based on the operation of the shift device 11 by the driver, and switches the switching mechanism K between the reverse state and the reverse release state. As a result, the vehicle is switched between forward and reverse.

(When moving forward)
When the shift device 11 is operated by the driver to move the vehicle forward, the first input shaft 1 and the second input shaft 2 are disconnected from the rotation of the engine, and as shown in FIG. The switching mechanism K is in a reverse release state (a state in which the sleeve 84 is detached from the second reverse idle gear 2r). In this state, the sleeve 82 of the second selection mechanism S2 is engaged with the first speed driven gear 1b, and the rotation of the engine is input only to the first input shaft 1. That is, with the clutch between the engine crankshaft and the second input shaft 2 disengaged, the clutch between the crankshaft and the first input shaft 1 is engaged as the accelerator pedal is depressed. As a result, the torque flow becomes the engine, the first input shaft 1, the first speed drive gear 1a, the first speed driven gear 1b, the second selection mechanism S2, and the output shaft 3, and the output shaft 3 rotates corresponding to the first speed, Move forward (start) at the first speed. At this time, prior to shifting up to the second speed, the sleeve 81 of the first selection mechanism S1 is engaged with the second speed driven gear 2b in advance. Thereby, although the 2nd input shaft 2 is rotationally driven by rotation of the output shaft 3, since it is isolate | separated from the crankshaft, it does not interfere with rotation of an engine.

(Shifting when moving forward)
When shifting up from 1st gear to 2nd gear when traveling forward, that is, when the shift device 11 is shifted up by the driver, or automatically shifted up according to the engine operating state and the vehicle traveling state The engine rotation input target is switched from the first input shaft 1 to the second input shaft 2. That is, the clutch between the crankshaft of the engine and the first input shaft 1 is disengaged, and at the same time, the clutch between the crankshaft and the second input shaft 2 is engaged. As a result, the torque flow becomes the engine, the second input shaft 2, the second speed drive gear 2a, the second speed driven gear 2b, the first selection mechanism S1, and the output shaft 3, and the output shaft 3 rotates at a speed equivalent to the second speed. An instantaneous shift up from 2 to 2nd without torque interruption is achieved. At this time, the first input shaft 1 is rotationally driven by the rotation of the output shaft 3, but is not separated from the crankshaft, so that it does not interfere with the rotation of the engine. The downshift from the 2nd speed to the 1st speed can be similarly performed an instantaneous downshift without running out of torque by performing the reverse procedure to the above. Shift up from 2nd gear to 3rd gear, 3rd gear to 4th gear, 4th gear to 5th gear, 5th gear to 6th gear, and shift down with the same procedure. Can be done.

(Backward: Normal reverse)
FIG. 2 is an explanatory diagram showing the normal reverse of the transmission M. When the shift device 11 is operated by the driver to reverse (usually reverse) the vehicle, first, the first input shaft 1 and the second input shaft 2 are disconnected from the rotation of the engine. As shown in FIG. 2, the switching mechanism K of the reverse idle gear mechanism R is in the reverse state (the state where the sleeve 84 is engaged with the second reverse idle gear 2r), and the sleeve 81 of the first selection mechanism S1 is Engaged with the 4-speed driven gear 4b. Either the engagement of the sleeve 84 with the second reverse idle gear 2r or the engagement of the sleeve 81 with the fourth speed driven gear 4b may be either first or simultaneously. Thereafter, the rotation of the engine is input only to the first input shaft 1. That is, the clutch between the crankshaft and the first input shaft 1 is connected with the clutch between the crankshaft of the engine and the second input shaft 2 disengaged.

  Thereby, as shown by the broken line in FIG. 2, the torque flow is the engine, the first input shaft 1, the first speed drive gear 1a, the first speed driven gear 1b, the reverse idle gear mechanism R, the sixth speed drive gear 6a, and the second input. The shaft 2, the fourth speed drive gear 4a, the fourth speed driven gear 4b, the first selection mechanism S1, and the output shaft 3 are provided. The reverse idle gear mechanism R reverses the rotation of the first input shaft 1 and transmits it to the second input shaft 2, so that the output shaft 3 rotates in the direction opposite to the forward movement, and the vehicle moves backward. At this time, the second input shaft 2 separated from the crankshaft of the engine is used as an idler for transmitting torque flow during reverse.

  In the present embodiment, the first reverse idle gear 1r is a first-speed driven gear that is the lowest gear among a plurality of gears (first-speed driven gear 1b, third-speed driven gear 3b, and fifth-speed driven gear 5b) constituting the first driven gear 1Dn. Meshes with 1b. In addition, the second reverse idle gear 2r is the highest gear among a plurality of gears (second speed drive gear 2a, fourth speed drive gear 4a, sixth speed drive gear 6a) constituting the second drive gear 2Dv. It meshes with the high-speed drive gear 6a. As a result, the reduction ratio during reverse can be increased as much as possible.

(Backward: Extra reverse)
FIG. 3 is an explanatory diagram showing the time when the transmission M is in an extra reverse (a gear ratio lower than that of normal reverse). When the shift device 11 is operated by the driver to reverse the vehicle at a gear ratio lower than normal reverse (extra reverse), first, the first input shaft 1 and the second input shaft 2 are disconnected from the rotation of the engine. . As shown in FIG. 3, the switching mechanism K of the reverse idle gear mechanism R is in the reverse state (the sleeve 84 is engaged with the second reverse idle gear 2r), and the sleeve 81 of the first selection mechanism S1 is Engaged with the second speed driven gear 2b. Either the engagement of the sleeve 84 with the second reverse idle gear 2r or the engagement of the sleeve 81 with the second speed driven gear 2b may be either first or simultaneously. Thereafter, the rotation of the engine is input only to the first input shaft 1. That is, the clutch between the crankshaft and the first input shaft 1 is connected with the clutch between the crankshaft of the engine and the second input shaft 2 disengaged.

  As a result, the torque flow is indicated by a broken line in FIG. 3. The engine, the first input shaft 1, the first speed drive gear 1 a, the first speed driven gear 1 b, the reverse idle gear mechanism R, the sixth speed drive gear 6 a, and the second input The shaft 2, the second speed drive gear 2a, the second speed driven gear 2b, the first selection mechanism S1, and the output shaft 3 are provided. As a result, the output shaft 3 is decelerated in accordance with the relative gear ratio (step ratio, for example, about 1.9) between the 4th speed and the 2nd speed as compared with the time of the normal reverse, and rotates in the direction opposite to the time of the forward movement. Therefore, the vehicle moves backward with a gear ratio lower than that during normal reverse, and the climbing force is improved.

(Reverse: High-speed reverse)
FIG. 4 is an explanatory diagram showing the high speed reverse (higher gear ratio than normal reverse) of the transmission M. When the shift device 11 is operated by the driver to reverse the vehicle at a higher gear ratio than normal reverse (high speed reverse), first, the first input shaft 1 and the second input shaft 2 are disconnected from the rotation of the engine. It is. As shown in FIG. 4, the switching mechanism K of the reverse idle gear mechanism R is in the reverse state (the state where the sleeve 84 is engaged with the second reverse idle gear 2r), and the sleeve 81 of the first selection mechanism S1 is The neutral state (the sleeve 81 is not engaged with the second speed driven gear 2b and the fourth speed driven gear 4b), and the sleeve 82 of the second selection mechanism S2 is engaged with the sixth speed driven gear 6b. Thereafter, the rotation of the engine is input only to the first input shaft 1.

  As a result, the torque flow is indicated by a broken line in FIG. 4. The engine, the first input shaft 1, the first speed drive gear 1a, the first speed driven gear 1b, the reverse idle gear mechanism R, the sixth speed drive gear 6a, and the sixth speed driven gear. 6b, the second selection mechanism S2, and the output shaft 3. As a result, the output shaft 3 is increased according to the relative gear ratio between the fourth speed and the sixth speed as compared with the normal reverse, and rotates in the direction opposite to the forward speed. Therefore, the vehicle moves backward at a higher gear ratio than that during normal reverse, and the reverse speed is improved.

(Shift during reverse)
When reverse driving is performed (shifting) between normal reverse, extra reverse, and high speed reverse described above, the first input shaft 1 and the second input shaft 2 are disconnected from the rotation of the engine prior to shifting. As a result, the first selection mechanism S1 and the second selection mechanism S2 are released from the torque of the engine, and gear shifting is possible. When shifting from normal reverse to extra reverse, the sleeve 81 of the first selection mechanism S1 is moved from the state engaged with the fourth speed driven gear 4b to engage with the second speed driven gear 2b. Thereafter, the rotation of the engine is input only to the first input shaft 1. As a result, the speed is changed from normal reverse to extra reverse. When shifting from the extra reverse to the normal reverse, the moving direction of the sleeve 81 is reversed.

  When shifting from normal reverse to high speed reverse, the first input shaft 1 and the second input shaft 2 are similarly disconnected from the rotation of the engine. Then, the sleeve 81 of the first selection mechanism S1 is moved from the state engaged with the fourth speed driven gear 4b to the neutral position, and the sleeve 82 of the second selection mechanism S2 is moved so as to be engaged with the sixth speed driven gear 6b. . Thereafter, the rotation of the engine is input only to the first input shaft 1. As a result, the speed is changed from normal reverse to high speed reverse. When shifting from high speed reverse to normal reverse, the moving directions of the sleeves 81 and 82 are reversed. Similarly, a shift between extra reverse and high speed reverse is also possible.

  Switching between normal reverse, extra reverse, and high speed reverse (shift up, shift down) is performed automatically in accordance with the engine operating state and the vehicle traveling state in reverse, in addition to manual shifting by the driver operating the shift device 11. It may be done by automatic transmission. In the case of automatic gear shifting, for example, when the engine speed (rpm) rises above a predetermined threshold during reverse traveling by extra reverse, the first input shaft 1 and the second input shaft 2 rotate the engine based on a command from the ECU 10. After being disconnected from, it is usually shifted up to reverse. Similarly, the engine speed is shifted up from normal reverse to high speed reverse using the engine speed as a parameter. The same applies to the downshift.

(Action / Effect)
According to the transmission according to the present embodiment, as shown in FIGS. 2 and 3, during reverse, the rotation of the first input shaft 1 is reversed by the reverse idle gear mechanism R and transmitted to the second input shaft 2. The plurality of second driven gears 2Dn (second speed driven gear 2b, fourth speed driven gear 4b, and sixth speed driven gear 6b) inserted through the output shaft 3 rotate in the opposite direction to that during forward movement. Therefore, the selection mechanism S (the first selection mechanism S1 and the second selection mechanism S2) selects any one of the second speed driven gear 2b, the fourth speed driven gear 4b, and the sixth speed driven gear 6b constituting the second driven gear 2Dn. By fixing the output shaft 3 so as not to rotate relative to the output shaft 3, a shift at the time of reverse is possible.

  Here, since the selection mechanism S (the first selection mechanism S1 and the second selection mechanism S2) also serves as a speed change mechanism at the time of forward movement, a part having a longer shaft length (a dedicated part for reverse speed change) is added. Thus, it is possible to realize a transmission M that can perform a shift at the time of reverse. At the time of reverse, the second input shaft 2 is disconnected from the rotation of the engine, and is used as an idler for transmitting torque flow at the time of reverse.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various modifications within the scope of the claims. Needless to say, examples or modifications also belong to the technical scope of the present invention.

  For example, a plurality of second drive gears with different numbers of teeth are rotatably inserted into the second input shaft 2, and a plurality of second driven gears respectively meshed with the second drive gears are fixed to the output shaft 3, A selection mechanism for selecting any one of the second drive gears described above and fixing the second drive gear to the second input shaft so as not to be relatively rotatable may be provided. Even with this configuration, the same operational effects as those of the above-described embodiments can be obtained.

  The present invention can be used for a transmission capable of shifting during reverse.

DESCRIPTION OF SYMBOLS 1 1st input shaft 2 2nd input shaft 3 Output shaft M Transmission 1Dv 1st drive gear 1a 1st speed drive gear as 1st drive gear 3a 3rd speed drive gear as 1st drive gear 5a As 1st drive gear 5th drive gear 2Dv 2nd drive gear 2a 2nd drive gear as 2nd drive gear 4a 4th drive gear as 2nd drive gear 6a 6th drive gear as 2nd drive gear 1Dn 1st driven gear 1b 1st driven gear 1b driven gear 3b 3rd driven gear as first driven gear 5b 5th driven gear as 1st driven gear 2Dn 2nd driven gear 2b 2nd driven gear as 2nd driven gear 4b 4th driven gear 6b as 2nd driven gear 6b 2nd gear 6-speed driven gear S selection as Bungiya mechanism R reverse idle gear mechanism 1r first reverse idle gear 2r second reverse idle gear K changeover mechanism

Claims (6)

A transmission having a first input shaft and a second input shaft to which rotation of an engine is selectively input, and an output shaft from which rotation after shifting is output,
A first drive gear fixed to the first input shaft;
A plurality of second drive gears having different numbers of teeth fixed to the second input shaft;
A first driven gear that is rotatably inserted into the output shaft and meshes with the first drive gear;
A plurality of second driven gears rotatably inserted into the output shaft and meshing with the second drive gears;
A selection mechanism for selecting any one of the second driven gears and fixing the output shaft to the output shaft so as not to be relatively rotatable;
A reverse idle gear mechanism that is interposed between the first driven gear and the second drive gear and reverses the rotation of the first input shaft and transmits the reverse rotation to the second input shaft. Gearbox to do. A transmission having a first input shaft and a second input shaft to which rotation of an engine is selectively input, and an output shaft from which rotation after shifting is output,
A first drive gear fixed to the first input shaft;
A plurality of second drive gears having different numbers of teeth, rotatably inserted in the second input shaft;
A first driven gear that is rotatably inserted into the output shaft and meshes with the first drive gear;
A plurality of second driven gears fixed to the output shaft and respectively meshing with the second drive gear;
A selection mechanism for selecting any one of the second drive gears and fixing the second drive gear to the second input shaft so as not to be relatively rotatable;
A reverse idle gear mechanism that is interposed between the first driven gear and the second drive gear and reverses the rotation of the first input shaft and transmits the reverse rotation to the second input shaft. Gearbox to do. The reverse idle gear mechanism is
A first reverse idle gear meshed with the first driven gear;
A second reverse idle gear meshed with any of the second drive gears;
The transmission according to claim 1, further comprising a switching mechanism that switches between a state in which the rotation of the first reverse idle gear is transmitted to the second reverse idle gear and a state in which the rotation is not transmitted to the second reverse idle gear. The first drive gear is composed of a plurality of odd speed gears or even speed gears,
The second drive gear includes a plurality of even speed transmission gears when the first drive gear is an odd speed transmission gear, and a plurality of odd speed transmission gears when the first drive gear is an even speed transmission gear. The transmission according to claim 3, comprising: The first reverse idle gear is meshed with the lowest gear among the plurality of gears constituting the first drive gear;
The transmission according to claim 4, wherein the second reverse idle gear is meshed with a gear at a highest speed among a plurality of gears constituting the second drive gear.   The transmission according to any one of claims 1 to 5, wherein the second input shaft is a hollow shaft, and the first input shaft is inserted therein so as to be relatively rotatable.

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