JP7152775B2 - Drum type transmission and vehicle equipped with it - Google Patents

Description

The present invention relates to a drum-type transmission and a vehicle equipped with the same.

2. Description of the Related Art A drum-type transmission has been proposed as a transmission used in a traveling system transmission path or the like in work vehicles such as utility vehicles and tractors (see, for example, Patent Document 1).

The conventional drum-type transmission described in Patent Document 1 includes a speed change gear supported relatively rotatably on a first transmission rotary shaft, and a speed change gear supported relatively non-rotatably on a second transmission rotary shaft and directly or indirectly connected to the speed change gear. a transmission gear meshed positively; a shifter member supported by a first transmission rotary shaft so as to be non-rotatable relative to and axially movable; a drum member having a fork guide groove and rotatably operated around the axis; A shift fork having a fork shaft parallel to the member, a boss portion axially movably supported on the fork shaft, an engagement pin portion engaged with the fork guide groove, and a fork portion engaged with the shifter member. ing.

More specifically, gearshift concave and convex portions are provided on the opposing end faces of the shifter member and the gear. By rotating the drum member around the axis, the shift fork whose axial position is restricted by the fork guide groove is moved in the axial direction, and the shifter member engages the transmission gear in an uneven manner. As a result, the gear train including the transmission gear and the transmission gear enters the power transmission state, and power is transmitted between the first and second transmission rotary shafts at the gear ratio of the gear train.

By the way, in such a drum-type transmission, in addition to the power transmission state by the gear train, it is desired to exhibit a parking state in which the rotation is forcibly stopped. In this respect, in addition to the above configuration, the conventional drum-type transmission includes a parking gear supported by the first transmission rotary shaft so as not to rotate relative to the parking gear, and a parking gear in response to the rotational movement of the drum member around the axis to the parking position. and a parking lock mechanism that engages an operating arm (called a park pole or the like) with the parking gear to forcibly stop the rotation of the first transmission rotary shaft.

The parking lock mechanism includes a locking member provided on the drum member and a plate member having a concave portion into which the locking member can enter. The plate member is rocked by the member entering the recess, and the parking gear is locked using the rocking of the plate member.

Japanese Patent No. 5909400

In a conventional drum-type transmission, when a shift lever provided in a vehicle equipped with a drum-type transmission is abruptly actuated and the parking state is released, the vehicle may become unintentionally parked, especially when the vehicle is parked on a slope. There was a fear that it would move without doing anything.

SUMMARY OF THE INVENTION An object of the present invention is to reliably operate a parking lock mechanism.

A drum-type transmission according to the present invention includes a transmission shaft having a plurality of transmission gears, a drum member for performing a shift operation, and a transmission operation arm for rotating the drum member via a shift gear train. a parking gear provided so as not to rotate relative to the parking gear; a parking operating arm displaceable between a locked position engaged with the parking gear and an unlocked position separated from the parking gear; A drum-type transmission provided with a parking lock mechanism having a parking pusher member that pushes the parking operating arm to the lock position in accordance with a rotational movement to the parking position, wherein the drum member is A parking lock holding mechanism is provided that, when in the parking position, engages a gear lock member with a lock member engaging portion provided on one of the plurality of shift gears constituting the shift gear train to prohibit rotation of the shift gear. It is.

According to the drum-type transmission of the present invention, when the drum member is positioned at the parking position, the gear lock member can be engaged with the lock member engaging portion provided on the shift gear of the shift gear train to prohibit rotation of the shift gear. As a result, it is possible to prevent the vehicle equipped with the drum-type transmission from being released from the parking state due to abrupt actuation of the shift lever provided on the vehicle while the vehicle is parked.

In the drum-type transmission of the present invention, the parking lock holding mechanism includes an electric actuator that slides the gear lock member in a direction to engage and disengage the lock member engagement portion, and when the electric actuator is de-energized, The gear lock member may be configured to be biased toward the direction of engagement with the lock member engaging portion.

According to this aspect, although the configuration is simple using the electric actuator, the gear lock member is locked when the drum member is positioned at the parking position even when power cannot be supplied to the electric actuator due to, for example, a dead battery. Engagement with the member engaging portion can reliably inhibit the operation of the shift gear train.

Further, the electric actuator may be composed of a solenoid having a linearly moving plunger, and the gear lock member may be provided at the tip of the plunger.

According to this aspect, the parking lock holding mechanism can be realized with a simple and simple configuration, and an increase in manufacturing cost can be suppressed.

A vehicle according to the present invention is a vehicle equipped with the drum-type transmission according to the present invention, wherein a brake operating tool for braking the wheels is actuated, an ignition switch is turned on, and a shift lever is operated for operating the shift operating arm. is in the parking position, the control device operates the electric actuator so as to release the engagement of the gear lock member with the lock member engaging portion.

According to the vehicle of this embodiment, the interlock state of the parking lock holding mechanism (the gear lock member is engaged with the lock member engaging portion and the operation of the shift lever of the vehicle is disabled while the vehicle is in a state where the vehicle can travel and is stopped reliably). Impossible state) can be released and movement of the vehicle immediately after rotation of the drum member from the parking position to another operating position can be prevented.

The drum-type transmission of the present invention can reliably operate the parking lock mechanism.

1 is a schematic plan view partially showing a skeleton diagram of a vehicle power transmission mechanism to which an embodiment of a drum-type transmission mechanism is applied; FIG. FIG. 3 is a schematic cross-sectional view developed along the speed change shaft, the power input shaft, the rear wheel output shaft, and the front wheel output shaft of the same embodiment. FIG. 4 is a schematic cross-sectional view developed along a reverse idle shaft, a fork shaft, a drum member, and a speed change operation shaft of the same embodiment; 4 is a cross-sectional view corresponding to the AA position in FIG. 3, (A) showing the parking release state, and (B) showing the parking state. FIG. 8 is a cross-sectional view for explaining a parking lock mechanism in another embodiment of the drum-type transmission mechanism, (A) showing a parking release state, and (B) showing a parking state; 4 is a cross-sectional view corresponding to the BB position in FIG. 3, (A) showing the parking release state, and (B) showing the parking state. FIG. 2 is a configuration diagram schematically showing a parking lock holding mechanism and its control system; 4 is a flow chart for explaining the operation of a parking lock holding mechanism; FIG. 5 is a cross-sectional view showing a modification of the parking lock holding mechanism;

An embodiment embodying the present invention will be described below with reference to the drawings. FIG. 1 shows a transmission schematic diagram of a work vehicle 1000 to which a drum-type transmission 1 according to this embodiment is applied. The drum-type transmission 1 is suitably used in a travel system transmission path of work vehicles such as tractors and utility vehicles. First, a schematic configuration of the work vehicle 1000 will be described with reference to FIG.

The work vehicle 1000 includes a vehicle body 8, an engine 2 as a drive source supported by the vehicle body 8, rear wheels 4 and front wheels 6 supported by the vehicle body 8, driving wheels of the rear wheels 4 and the front wheels 6 from the engine 2. and a drum-type transmission 1 inserted in a power transmission mechanism 3 leading to the wheels acting as a transmission.

The power transmission mechanism 3 transmits the power of the engine 2 via a drum-type transmission 1 in a transmission 800 located behind the engine 2 to a front axle drive 7 located in front of the engine 2 and a drum-type transmission. 1 to the rear transaxle 5 arranged in the transmission 800 .

The power transmission mechanism 3 includes a belt transmission 21 driven by the engine 2, and a transmission 800 having a drum type transmission 1 driven by the belt transmission 21 and a rear axle drive 5. . The rear axle drive device 5 drives a pair of left and right rear wheels 4 and a rear axle 4a. In front of the engine 2, a front axle drive device 7 for driving a pair of left and right front wheels 6 and a front axle 6a is provided. The output of the drum type transmission 1 is distributed and transmitted to the rear axle drive 5 and the front axle drive 7 .

As shown in FIG. 1, the belt transmission 21 includes a drive pulley 22 and a driven pulley 23 arranged in front and behind, and an endless belt 24 is wound around the drive pulley 22 and the driven pulley 23 . The driving pulley 22 is non-rotatably attached to the power output shaft 30 of the engine 2 extending in the lateral direction of the vehicle body, and the driven pulley 23 is non-rotatably attached to the power input shaft 820 of the transmission 800 extending in the lateral direction of the vehicle body. The power output shaft 30 serves as the rotation center shaft (pulley shaft) of the drive pulley 22 , and the power input shaft 820 serves as the rotation center shaft (pulley shaft) of the driven pulley 23 . The belt transmission 21 is a continuously variable transmission configured to change the width of the pulley grooves of both pulleys 22 and 23 in accordance with the change in the rotation speed of the engine 2, thereby continuously changing the output/input rotation speed ratio. (CVT). A power input shaft 820 of the transmission 800 constitutes a power input shaft of the drum-type transmission 1 provided inside the transmission 800 .

The rear axle drive device 5 is provided in the transmission 800 and includes a rear wheel differential gear mechanism 830 to which the output of the drum type transmission 1 is input, and a pair of left and right rear wheel output shafts 840 extending in the left-right direction. . Each rear wheel output shaft 840 protrudes left and right outwards from the transmission housing 805, and is interlockingly connected to the rear axles 4a of the left and right rear wheels 4 via universal joints and transmission shafts. The rear-wheel differential gear mechanism 830 is housed in the transmission housing 805, and the left and right rear-wheel output shafts 840 are connected to each other via the rear-wheel differential gear mechanism 830 so as to be capable of differential operation.

The front axle drive device 7 supports an input shaft 71 extending in the front-rear direction of the vehicle body in plan view and a pair of left and right output shafts 73 extending in the left-right direction in a front axle drive housing 70 as a housing thereof. Each output shaft 73 of the front axle drive device 7 protrudes left and right outward from the front axle drive housing 70, and is interlockingly connected to the front axle 6a of each of the left and right front wheels 6 via a universal joint and a transmission shaft. A front wheel differential mechanism (not shown) is housed inside the front axle drive housing 70, and the left and right output shafts 73 are connected to each other via the front wheel differential mechanism so as to be able to differentially operate. The rear end of the input shaft 71 protrudes rearward from the front axle drive housing 70, through a universal joint 91, a front power transmission shaft 92, a universal joint 93, a rear power transmission shaft 94 and a shaft coupling 95 in order from the front side. It is connected to the front end of a front wheel output shaft 850 projecting forward from the transmission housing 805 of the transmission 800 .

In this embodiment, both the rear wheels 4 and the front wheels 6 of the work vehicle 1000 act as drive wheels. Specifically, the work vehicle 1000 has a pair of left and right rear wheels 4 acting as main drive wheels and a pair of left and right front wheels 6 acting as auxiliary drive wheels and also as steering wheels. Rotational power changed by the device 1 is transmitted to the rear wheels 4 and the front wheels 6 .

Next, the drum type transmission 1 will be described with reference to FIGS. 1 to 4. FIG. FIG. 2 is a sectional view developed along the transmission shaft 810, the power input shaft 820, the rear wheel output shaft 840, and the front wheel output shaft 850. As shown in FIG. FIG. 3 is a cross-sectional view developed along the reverse idle shaft 16, the fork shaft 120, the drum member 140, and the shift operating shaft 150. As shown in FIG.

The drum-type transmission 1 can transmit rotational power between a transmission shaft 810 and a power input shaft 820 which are provided parallel to each other. Specifically, as shown in FIGS. 1 to 3, the drum-type transmission 1 includes a speed change gear 10 supported relatively rotatably on a speed change shaft 810 and a power input shaft 820 supported non-rotatably (or integrally). a transmission gear 20 directly or indirectly meshed with the speed change gear 10, and a drum-type speed change operation mechanism 100 selectively bringing the speed change gear 10 into a power transmission state.

In this embodiment, the transmission gear 10 has a forward high-speed transmission gear 10H, a forward low-speed transmission gear 10L, and a reverse transmission gear 10R. The transmission gear 20 includes a transmission gear 20H that meshes with the transmission gear 10H to form a forward high-speed gear train together with the transmission gear 10H, and a transmission gear 20L that meshes with the transmission gear 10L to form a forward low-speed gear train together with the transmission gear 10L. , and a transmission gear 20R which meshes with the speed change gear 10R via a reverse idle gear 15 (see FIG. 3) to form a reverse gear train together with the speed change gear 10R and the reverse idle gear 15. As shown in FIG.

In this embodiment, the power input shaft 820 acts as a speed change input shaft for operationally inputting rotational power from a drive source such as the engine 2, and the speed change shaft 810 outputs the rotational power after shifting to the driving wheels. It acts as a speed change output shaft. A transmission output gear 11 that meshes with a final gear 831 of a rear wheel differential gear mechanism 830 is fixed to the transmission shaft 810 , and the transmission shaft 810 rotates together with the rear wheels 4 . In addition, a driven bevel gear 833 attached to the rear end of the front wheel output shaft 850 so as not to rotate relative to the drive bevel gear 832 attached to one end (the right end in this embodiment) of the speed change shaft 810 meshes, The rotational power of transmission shaft 810 is also transmitted to front wheel output shaft 850 .

That is, as shown in FIGS. 1 and 2, the transmission 800 is attached to the transmission housing 805 with one end extending outward so as to be operatively connected to the transmission housing 805 and the engine 2 as a drive source. A power input shaft 820 that is rotatably supported around the axis and acts as a speed change input shaft, a speed change shaft 810 that is supported rotatably around the axis and acts as a speed change output shaft, and a power input shaft 820 to the speed change shaft 810. and a drum-type transmission 1 for multi-speed transmission of rotational power.

The transmission 800 further differentially transmits the rotational power operatively input from the pair of left and right rear wheel output shafts 840 and the transmission output shaft (transmission shaft 810) to the pair of left and right rear wheel output shafts 840. A rear axle drive 5 with a wheel differential gear mechanism 830 is provided. The transmission 800 also includes a front wheel output shaft 850 that outputs the rotational power of the transmission shaft 810 to a transmission path different from the rear wheel output shaft 840 .

The drum-type shift operation mechanism 100 is configured to selectively bring a plurality of speed change gears 10 into a power transmission state, thereby bringing the drum-type transmission 1 into a desired shift stage engaged state.

Specifically, as shown in FIGS. 1 to 3, the drum-type speed change operation mechanism 100 is supported by the speed change shaft 810 so as to be non-rotatable relative to the speed change shaft 810 and movable in the axial direction. A shifter member 110 that is mated with a shifter member 110, a fork shaft 120 that is parallel to the transmission shaft 810, a shift fork 130 that is axially movably supported by the fork shaft 120, and a drum member that is rotated around an axis parallel to the transmission shaft 810. 140.

More specifically, shifter member 110 and transmission gear 10 are provided with gearshift uneven portions 112, 12, respectively, on the opposing end faces, and move shifter member 110 along the axial direction in a direction closer to transmission gear 10. As a result, the transmission uneven portion 112 of the shifter member 110 engages with the transmission uneven portion 12 of the transmission gear 10, thereby establishing a power transmission state in which the transmission gear 10 rotates integrally with the transmission shaft 810 via the shifter member 110. becomes.

As shown in FIGS. 1 to 3, in the present embodiment, a transmission gear 10H, a transmission gear 10R, and a transmission gear 10L are arranged on the transmission shaft 810 in order from left to right in the axial direction.

The drum-type speed change operation mechanism 100 is supported as a shifter member 110 between the speed change gear 10H and the speed change gear 10R by the speed change shaft 810 so as to be non-rotatable relative to and axially movable. A first shifter member 110HR that engages with the transmission gear 10H and the transmission gear 10R in a concave-convex manner, and a shift shaft 810 that is supported at a position facing the transmission gear 10L so as to be axially movable and non-rotatable relative to the transmission gear 10L. and a second shifter member 110L that engages with the transmission gear 10L in a concave-convex manner according to movement toward the side (in this embodiment, the left side in the axial direction).

The first shifter member 110HR has a high-speed concave-convex portion 112H that can be engaged in concave-convex engagement with the speed-change concave-convex portion 12H of the transmission gear 10H on the end face on the left side in the axial direction facing the transmission gear 10H. On the opposite end face on the right side in the axial direction, there is provided a reverse movement uneven portion 112R that can be unevenly engaged with the transmission uneven portion 12R of the transmission gear 10R.

The second shifter member 110L has a low-speed concave-convex portion 112L that can concave-convex-engage with the shift concave-convex portion 12L of the speed change gear 10L on the axially left end face facing the speed change gear 10L.

In addition, as shown in FIG. 3, the drum-type gear shift operation mechanism 100 includes first and second shift forks 130HR and 130L for axially moving the first and second shifter members 110HR and 110L, respectively, as the shift fork 130. have.

As shown in FIG. 3 and the like, the first shift fork 130HR is engaged with a first boss portion 132HR supported axially movably on the fork shaft 120 and a first fork guide groove 142HR formed in the drum member 140. and a first fork portion 136HR that engages with the first shifter member 110HR. 110HR is moved axially on the transmission shaft 810 .

Specifically, the first shift fork 130HR and the first shifter member 110HR have a reference position in which the first shifter member 110HR does not engage the transmission gear 10H and the transmission gear 10R in an uneven manner, and a reference position in which the first shifter member 110HR can take a high speed position where the shift gear 10H is engaged with the transmission gear 10H and a reverse position where the first shifter member 110HR is engaged with the transmission gear 10R. Note that FIG. 3 shows a state in which the first shift fork 130HR and the first shifter member 110HR are positioned at the reference positions.

The second shift fork 130L includes a second boss portion 132L axially movably supported by the fork shaft 120 and a second engagement pin portion engaged with a second fork guide groove 142L formed in the drum member 140. 134L and a second fork portion 136L that engages with the second shifter member 110L. It is designed to move in the direction.

Specifically, the second shift fork 130L and the second shifter member 110L are positioned at a reference position where the second shifter member 110L does not engage with the transmission gear 10L in an axial direction, and a low speed position with concave and convex engagement. Note that FIG. 3 shows a state in which the second shift fork 130L and the second shifter member 110L are positioned at the reference positions.

The drum member 140 is adapted to rotate about its axis in accordance with a shift operation. In this embodiment, as shown in FIG. 3, the drum-type gearshift operating mechanism 100 is provided with a gearshift operating shaft 150 for receiving a gearshift operation, and the drum member 140 is operatively connected to the gearshift operating shaft 150. . In this embodiment, the shift operating shaft 150 is operatively connected to the drum member 140 via the shift gear train 200 .

The shift operation shaft 150 is arranged to extend in the left-right direction of the vehicle in parallel with the rotation axis of the drum member 140. One end 150a (the left end in this embodiment) is arranged inside the transmission housing 805, and the other end is arranged inside the transmission housing 805. 150b (the right end in this embodiment) is supported by the transmission housing 805 so as to be rotatable about the axis while extending outward. As shown in FIGS. 1 and 3, the shift operating shaft 150 is rotated about its axis by, for example, a shift operating arm 155 attached to the other end 150b.

Instead of this, it is also possible to rotate the speed change operation shaft 150 around the axis by an electric motor. In this case, the shift operating arm 155 is removed, and an electric motor (not shown) is attached to the other end portion 150b of the shift operating shaft 150. FIG. In this case, it is preferable to provide an angle sensor (not shown) for detecting the position of the drum member 140 around the axis.

As shown in FIG. 3, the drum member 140 includes a drum body 141 in which fork guide grooves (first and second fork guide grooves 142HR and 142L in this embodiment) are formed, and a drum body 141 coaxially with the drum body 141. and a drum shaft 148 that supports the main body 141 .

As shown in FIG. 3, the drum-type shift operation mechanism 100 further includes a first shift fork pushing spring 160HR that pushes the first boss portion 132HR to the left in the axial direction, and a first boss portion 132HR that is axially movable. and a slider member pushing spring 180 that pushes the slider member 170 to the right in the axial direction.

When the first shift fork 130HR is free, the first shift fork pushing spring 160HR presses the first boss portion 132HR with an urging force capable of moving the first shifter member 110HR to a high speed position where it engages with the transmission gear 10H. It is set to push to the left in the axial direction.

Specifically, the first shift fork pushing spring 160HR has a fixed end that is locked by a locking member 126 provided on the fork shaft 120 at its right end in the axial direction, and a left end in the axial direction. is a movable end engaged with the axially right end face of the first boss portion 132HR.

The slider member 170 is axially movably supported by the first boss portion 132HR with its axially rightward movement end defined by a stop portion 133 provided on the first boss portion 132HR. The position in the axial direction is regulated by a slider guide groove 144 provided in the .

Specifically, the slider member 170 has a slider main body 172 that is axially movably fitted onto the first boss portion 132 HR and a slider engagement pin portion 174 that engages with the slider guide groove 144 .

The slider member pushing spring 180 is configured to push the slider member 170 to the right in the axial direction with an urging force larger than that of the first shift fork pushing spring 160HR.

That is, when the first shift fork 130HR and the slider member 170 are free, the slider member pressing spring 180 is attached to the first shift fork pressing spring 160HR that biases the first shift fork 130HR to the first side in the axial direction. The first boss portion 132HR is pushed to the right in the axial direction via the slider member 170 with an urging force capable of moving the first shifter member 110HR to a reverse position where the first shifter member 110HR engages with the transmission gear 10R in an uneven manner against the force. is set.

Specifically, the slider member pressing spring 180 has a fixed end that is locked by a locking member 127 provided on the fork shaft at the left end in the axial direction, and a slider member at the right end in the axial direction. 170 is a movable end engaged with the end face on the left side in the axial direction.

In this embodiment, as shown in FIG. 3, the drum-type shift operation mechanism 100 further pushes the second boss portion 132L in the direction in which the second shifter member 110L is pressed toward the transmission gear 10L. A 2-shift fork pushing spring 160L is provided.

As described above, in this embodiment, the transmission gear 10L is positioned on the left side of the second shifter member 110L in the axial direction. Push.

Specifically, the second shift fork pushing spring 160L has a fixed end that is locked by a locking member 128 provided on the fork shaft 120 at its right end in the axial direction, and a left end in the axial direction. is a movable end engaged with the axially right end face of the second boss 132L.

When the second shift fork 130L is free, the second shift fork pushing spring 160L presses the second boss portion 132L with an urging force capable of moving the second shifter member 110L to a low speed position where it engages with the transmission gear 10L. It is set to push.

In the drum-type transmission 1, the drum member 140 is configured to take an axial operation position corresponding to a shift stage (including a neutral stage) that the drum-type transmission 1 can take.

In this embodiment, the drum-type transmission 1 is configured to be able to take a neutral stage, a forward high speed stage, a forward low speed stage, and a reverse stage. It is configured to assume a high speed position, a low speed position and a reverse position.

Specifically, in this embodiment, the drum member 140 assumes the high speed position when it is rotated in one direction about the axis from the neutral position, and assumes the low speed position when further rotated in one direction about the axis from the high speed position. It is configured to assume the reverse position when rotated from the position to the other side about the axis.

The drum-type transmission 1 can also take a parking stage, and the drum member 140 can take a parking position in addition to the operating position described above. In this embodiment, the drum member 140 is configured to take the parking position when it is further rotated to the other side around the axis from the reverse position. A configuration for making this parking state appear will be described later.

The drum-type shift operating mechanism 100 further includes a detent mechanism (not shown) that locks the drum member 140 at each of the operating positions. In the drum-type transmission 1 , the intermittent rotation of the drum member 140 provides the shift forks 130 HR and 130 L with increments according to the groove shapes of the fork guide grooves 142 HR and 142 L and the slider guide groove 144 . Thereby, the drum-type transmission 1 is set to one of the forward low speed state, the forward high speed state, the reverse driving state, the neutral state and the parking state. A configuration similar to that of the drum-type transmission 1 of the present embodiment is disclosed, for example, in Japanese Unexamined Patent Application Publication No. 2018-91376.

As is clear from FIG. 3, the drum member 140 rotates about the axis of the drum shaft 148 in accordance with the rotation of the shift operation shaft 150 operatively connected via the shift gear train 200 . A shift operation arm 155 is attached to one end (right end in this embodiment) of the shift operation shaft 150 so as not to rotate relative to it. The shift operation arm 155 rotates about the axis of the shift operation shaft 150 in conjunction with the operation of a shift operation tool (lever, pedal, dial, etc.) not shown. A detent mechanism (not shown) for locking the drum member 140 at each operating position is connected to the drum shaft 148 .

In the shift gear train 200 , a shift drive gear 201 fixed to a shift operation shaft 150 meshes with a first shift idle gear 203 fixed to a shift idle shaft 202 . A second shift idle gear 204 having a larger diameter than the first shift idle gear 203 is fixed to the shift idle shaft 202, and the first and second shift idle gears 203, 204 are provided so as not to rotate relative to each other. . The second shift idle gear 204 meshes with a shift gear 205 fixed to one end (the right end in this embodiment) of the drum shaft 148 . As the shift operation arm 155 rotates, the shift operation shaft 150 and the gears 201, 203 and 204 rotate, and the shift gear 205 and the drum shaft 148 rotate accordingly.

Here, the right end portion of the drum shaft 148, the speed change operation shaft 150 and the shift gear train 200 are accommodated in a shift gear chamber 805a provided on the outer side surface (the right side surface in this embodiment) of the transmission housing 805. The shift gear chamber 805a is separated from the internal space of the transmission housing 805 in which the drum body 141, the transmission gear 10, the transmission gear 20 and the like are accommodated by a partition wall 805b. The shift gear chamber 805a is covered with a detachable shift gear chamber cover 806, and the other end 150b of the speed change operation shaft 150 protrudes rightward from the shift gear chamber cover 806. As shown in FIG.

An example of the parking structure of the drum-type transmission 1 will be described below. FIG. 4 shows a cross-sectional view corresponding to the AA position in FIG. FIG. 4A shows the parking release state, and FIG. 4B shows the parking state (locked state).

As shown in FIGS. 3 and 4, in the drum-type transmission 1, the shift fork (the second shift fork 130L) moves in the axial direction to engage the corresponding transmission gear (the transmission gear 10L) in an uneven manner. A parking concavo-convex portion 112P facing radially outward is provided on the shifter member (second shifter member 110L) that puts the transmission gear in the power transmission state.

In addition, the drum-type transmission 1 is provided with a parking lock mechanism 500 that engages with the uneven portion 112P for parking to forcibly stop the rotation of the shifter member (second shifter member 110L). . In this embodiment, the second shifter member 110L having the uneven portion 112P for parking also serves as a parking gear.

In this manner, the drum-type transmission 1 is configured so that the shifter member (second shifter member 110L) that engages and disengages power transmission by the corresponding transmission gear (transmission gear 10L) also serves as a parking gear. As a result, it is possible to reduce the cost by reducing the number of parts and to reduce the size in the axial direction.

A parking gear, which is a member separate from the shifter member, may be provided on transmission shaft 810 so as not to be relatively rotatable, and parking concavo-convex portion 112P may be provided on the parking gear.

As shown in FIGS. 3 and 4, the parking lock mechanism 500 is swingable about a swing axis 505 parallel to the speed change shaft 810 that supports the second shifter member 110L, and has a parking concave and convex portion 112P at its free end. a parking release spring 520 that biases the parking operating arm 510 in the direction of parking release around the swing axis 505; and a parking pushing member 530. have.

The parking actuating arm 510 is moved around the pivot axis 505 to the lock position (FIG. 4B) where the engaging portion 515 is engaged with the parking uneven portion 112P to forcibly stop the rotation of the second shifter member 110L. )), and an unlocked position (see FIG. 4A) in which the engaging portion 515 is spaced radially outward from the parking concavo-convex portion 112P.

The parking pushing member 530 pushes the parking actuating arm 510 toward the locking position against the biasing force of the parking release spring 520 using the rotational movement of the drum member 140 to the parking position about the axis. do.

In the present embodiment, as shown in FIGS. 3 and 4, the parking pressing member 530 includes a pressing member main body portion 532 supported by the drum member 140 and radially outward from the pressing member main body portion 532. and a cam pushing portion 535 extending to the .

As shown in FIG. 4A, the cam pushing portion 535 acts on the parking operating arm 510 when the drum member 140 is positioned at the shift position and the neutral position (reverse position in the illustrated embodiment). As shown in FIG. 4B, the parking operation arm 510 is rotated against the urging force of the parking release spring 520 (see FIG. 3) by using the rotational movement of the drum member 140 to the parking position. toward the locked position.

In this embodiment, as shown in FIGS. 3 and 4, the parking actuation arm 510 includes a boss portion 512 that is relatively rotatably fitted around a pivot shaft 506 defining a swing axis 505, and a boss portion 512 that An engaging portion 515 is provided on the side of the free end portion of the arm portion 514 facing the uneven portion 112P for parking. A pressure receiving surface 516 with which the cam pushing portion 535 engages is provided on the side opposite to the uneven portion 112P.

In this embodiment, as shown in FIG. 3, the reverse idle shaft 16 that supports the reverse idle gear 15 forming the reverse gear train serves as the pivot shaft 506 that swingably supports the parking operating arm 510. It's being used. That is, the axis of the reverse idle shaft 16 constitutes the swing axis 505 of the parking operating arm 510 .

As shown in FIG. 3, the parking release spring 520 has one end operatively connected to the parking actuating arm 510 and the other end operatively connected to the pivot shaft 506 (via a pin 522 in this embodiment). It is a coil spring externally inserted on the pivot shaft 506 in this state.

In this embodiment, as described above, the drum member 140 assumes the reverse position when it is rotated from the neutral position to the other side about the axis, and assumes the parking position when it is further rotated to the other side about the axis from the reverse position. It has become. The operating position of the drum member 140 is determined by the operating position of the shift operating arm 155 . That is, when the speed change operation arm 155 is at the parking position P, the reverse position R, the neutral position N, the high speed position (high speed forward position) H, and the low speed position (low speed forward position) L, the drum member 140 is at the parking position, the reverse position, It is configured to have a neutral position, a high speed position and a low speed position.

Therefore, the cam pushing portion 535 is set when the speed change operation arm 155 is positioned at the reverse position R, the neutral position N, the high speed position H and the low speed position L (when the drum member 140 is at the neutral position, the reverse position, the high speed position and the low speed position). ), it does not engage with the pressure receiving surface 516, and when the shift operation arm 155 is rotated from the reverse position R toward the parking position P (when the drum member 140 moves from the reverse position toward the parking position) When rotated), it engages the pressure receiving surface 516 and pushes the parking actuation arm 510 toward the locked position against the biasing force of the parking release spring 520 .

Thus, in this embodiment, the parking pushing member 530 is supported by the drum member 140, so that the rotation of the drum member 140 to the parking position is used to move the parking actuation arm 510 to the locked position. It is possible to make the parking lock mechanism 500 that pushes toward the compact.

The drum-type transmission 1 according to the present embodiment further has the following configuration in order to achieve a standby action in the shifting operation to the parking stage.

That is, in this embodiment, the pressing member main body portion 532 of the parking pressing member 530 is externally fitted on the drum member 140 so as to be relatively rotatable.

3 and 4, the parking pressing member 530 and the drum member 140 are operatively connected at one end to the parking pressing member 530 and at the other end (a pin in this embodiment). 542) and through a parking coil spring 540 operatively connected to the drum member 140 and fitted over the drum member 140. As shown in FIG.

The parking coil spring 540 rotates the cam pressing member 535 relative to the drum member 140 so that the parking pressing member 530 rotates integrally with the rotation of the drum member 140 about the axis when the circumferential load applied to the cam pressing member 535 is less than a predetermined value. While the drum member 140 is non-rotatably connected, when the circumferential load applied to the cam pressing portion 535 exceeds a predetermined value, the drum member 140 is elastically deformed and the drum member 140 pre-rotates relative to the parking pressing member 530 around the axis. configured to allow

In this embodiment, the parking coil spring 540 is configured to be elastically deformed in the diameter contracting direction when the drum member 140 is pre-rotated relative to the parking pressing member 530 .

By providing such a configuration, it is possible to obtain a waiting action in the shift operation to the parking stage. That is, when the cam pushing portion 535 swings the parking operating arm 510 toward the locking position in response to the rotation of the drum member 140 to the parking position, the engaging portion 515 of the parking operating arm 510 is moved to the second position. Assume that a situation occurs in which the parking operating arm 510 cannot swing to the lock position due to being abutted against the convex portion of the uneven portion 112P for parking of the shifter member 110L.

In this case, a circumferential load exceeding a predetermined value is applied to the cam pressing portion 535 . Therefore, the drum member 140 rotates forward relative to the parking pressing member 530 about the axis to the parking position while elastically deforming the parking coil spring 540 .

The elastically deformed parking coil spring 540 has an elastic force that urges the parking pressing member 530 in a direction to follow the drum member 140, and the engaging portion 515 and the parking uneven portion 112P are aligned. At this stage, the parking actuating arm 510 is swung to the locked position against the biasing force of the parking release spring 520 by elastic force, and the engaging portion 515 and the uneven portion 112P for parking are engaged with each other to form the parking stage. The shift operation to 1 is completed (see FIG. 4(B)).

In the present embodiment, as shown in FIG. 4(B), when the cam pushing portion 535 positions the parking operating arm 510 at the lock position and the drum type transmission 1 is in the parking gear engagement state. , the direction of the reaction force acting on the cam pressing portion 535 from the pressure receiving surface 516 is substantially opposite to the direction in which the cam pressing portion 535 extends radially outward with respect to the axis of the drum member 140. (hereinafter referred to as a "stuck" configuration by the cam pushing portion 535).

By providing the "stuck" configuration by the cam pushing portion 535, it is possible to effectively prevent or prevent the uneven engagement between the engaging portion 515 of the parking actuation arm 510 and the parking uneven portion 112P from being unintentionally released. can be reduced.

More specifically, when the drum type transmission 1 is used in the traveling system transmission path of the work vehicle, the drum member 140 is positioned at the parking position while the work vehicle is located on a slope. 1 into the parking stage engaged state.

In such a situation, the gravity applied to the work vehicle is reversely transmitted from the drive wheels to the speed change shaft 810 , and rotational driving force around the axis acts on the speed change shaft 810 .

In general, the concave portion of the concave-convex engaging structure (in this embodiment, the concave portion of the parking concave-convex portion 112P) has a tapered cross-sectional shape that narrows radially inward, and is engaged with the concave portion. By making the lateral cross-sectional shape of the convex portion (the engaging portion 515 of the operating arm 510 for parking in this embodiment) a tapered shape corresponding to the concave portion, it is possible to ensure "easiness of engagement" of the concave-convex engagement. can be done.

On the other hand, if the cross-sectional shape of the concave portion of the uneven portion 112P for parking and the engaging portion 515 is tapered, when the reverse driving force is transmitted from the drive wheels to the speed change shaft 810, the reverse driving force is reduced. This acts as a force to swing the parking actuation arm 510 in the parking release direction, and the parking actuation arm 510 positioned at the lock position is unintentionally swung in the parking release direction, and the parking actuation is performed. A situation may arise in which the uneven engagement between the arm 510 and the parking uneven portion 112P is released.

In this regard, if the cam pressing portion 535 is provided with a "stuck" configuration, it is possible to effectively prevent or reduce the unintentional swinging of the parking actuation arm 510 from the locked position in the unlocking direction.

Further, in the present embodiment, as shown in FIG. 4 and the like, the cam pushing portion 535 is not engaged with the parking operating arm 510, that is, the drum member 140 is in the operation position from the low speed position to the reverse position. 2, the pushing member main body 532 of the parking pushing member 530 comes into contact with the parking operating arm 510 that is biased about the swing axis 505 in the parking release direction by the parking release spring 520. , to define the swing end of the parking actuation arm 510 in the parking release direction.

As shown in FIGS. 3 and 4, the shift operating shaft 150 is provided to pass through the partition wall 805b of the transmission housing 805 and the shift gear chamber cover 806, and one end 150a (the left end in this embodiment) of the shift operating shaft 150 is provided. ) are located within the transmission housing 805 and close to the parking actuation arm 510 . In this embodiment, the shift operating shaft 150 is provided at a position overlapping the parking operating arm 510 when viewed in the axial direction of the shift operating shaft 150 . An arm checking portion 156 provided at one end portion 150 a of the shift operating shaft 150 is inserted into an engaging hole 517 provided in an arm portion 514 of the parking operating arm 510 .

As shown in FIG. 4 , the arm restraint portion 156 is provided on the end surface of the one end portion 150 a of the shift operating shaft 150 and extends in the axial direction of the shift operating shaft 150 so as to be eccentric with respect to the axis of the shift operating shaft 150 . protruded towards. In this embodiment, the arm restraint portion 156 is formed by cutting out a portion of the peripheral wall of the one end portion 150a of the speed change operation shaft 150, and has a substantially fan-shaped columnar shape.

As shown in FIG. 4A, in the parking release state in which the parking operating arm 510 is positioned at the unlocked position, the parking operating arm 510 rotates the speed change operation shaft 150 (rotational displacement of the arm checking portion 156). configured so as not to interfere with In this embodiment, the engagement hole 517 of the parking operating arm 510 has the form of a circular through-hole with a diameter slightly larger than the shaft diameter of the speed change operation shaft 150. It is provided so as to substantially overlap the contour of the speed change operation shaft 150 when viewed from the direction. As a result, when the shift operating arm 155 is pivotally displaced between the reverse position R and the low speed position L, the arm restraint portion 156 is prevented from coming into contact with the inner peripheral wall of the engagement hole 517, and the shift operating arm 155 is moved. can prevent an increase in the operating resistance of

As shown in FIG. 4(B), in the parking state in which the parking actuation arm 510 is located at the locked position, the engagement hole 517 is positioned closer to the second shifter member than in the parking release state (see FIG. 4(A)). It is located near 110L (parking gear). When viewed from the axial direction of the shift operation shaft 150, a portion of the inner peripheral wall of the engagement hole 517 corresponds to the locus of movement of the arm checking portion 156 when the drum shaft 148 is rotated between the parking position and the reverse position. crossed.

The arm restraint portion 156 is attached to the inner peripheral wall of the engagement hole 517 when the speed change operation arm 155 rotates from the parking position P toward the reverse position R (when the drum member 140 rotates from the parking position toward the reverse position). It is configured to contact and bias the parking actuation arm 510 toward the unlocked position.

According to the drum-type transmission 1 of this embodiment, when the drum member 140 rotates from the parking position toward the shift position or the neutral position (reverse position R in this embodiment), the spring force of the parking release spring 520 is and an unlocking mechanism by an arm checking portion 156 provided on the speed change operation shaft 150 . As a result, even if the parking state is not released only by the spring force of the parking release spring 520 and the reaction force that the parking operation arm 510 receives from the second shifter member 110L (parking gear), the action of the arm restraining portion 156 You can definitely release the parking state. Thereby, the reliability of the parking lock mechanism 500 in the drum-type transmission 1 can be improved.

Furthermore, by providing an arm restraint portion 156 on the shift operating shaft 150 interlockingly connected to the drum member 140 and the parking pushing member 530, one operation system (operation of the shift operating shaft 150) can provide two unlocking mechanisms. can be operated. That is, it is possible to provide an unlocking mechanism by the arm restraint portion 156 without adding a separate operating system to the operating system for operating the rotation of the drum member 140 and the parking pushing member 530 using the shift operating shaft 150. The reliability of the parking lock mechanism 500 in the drum-type transmission 1 can be improved with a simple configuration and low cost.

Further, the arm restraint portion 156 is provided on the speed change operation shaft 150 positioned upstream of the transmission path of the rotational force that rotates the drum member 140 . Therefore, when the drum member 140 is rotated from the parking position toward the shift position or the neutral position, the release operation force input to the shift operation shaft 150 can be transmitted to the parking operating arm 510 without reducing the force. A large increase in force can be suppressed.

Furthermore, in the drum-type transmission 1 of the present embodiment, the arm checking portion 156 is formed by cutting the one end portion 150a of the shift operation shaft 150, so that the shift operation shaft 150 can be assembled without increasing the number of parts. Since the arm restraint portion 156 can be provided in the drum-type transmission 1, the reliability of the parking lock mechanism 500 in the drum-type transmission 1 can be improved with a low-cost and compact configuration without causing a significant increase in manufacturing cost.

When the parking lock is released, the arm checking portion 156 may always urge the parking operating arm 510 toward the unlocked position, or the cam pressing portion 535 of the parking pressing member 530 may The parking operating arm 510 may be urged toward the unlocked position only when the parking operating arm 510 does not separate from the parking uneven portion 112P even when the parking operating arm 510 is separated.

Further, the shape of the arm restraint portion 156 is not limited to the substantially fan-shaped columnar shape, and may be other shapes such as a columnar shape. Further, instead of the arm restraint portion 156 formed by cutting out a part of the shift operation shaft 150, the drum member 140 is moved from the parking position to the shift position or the neutral position at one end portion 150a of the shift operation shaft 150. It is also possible to construct an arm checking portion by attaching a separate member capable of urging the parking operating arm 510 toward the unlocked position.

Further, the engagement hole 517 in the parking operating arm 510 with which the arm restraining portion 156 contacts is not limited to a circular shape, and may be of other shapes such as an L-shaped groove. It may be released on the outer peripheral side surface of 510 . In addition, the location of the parking actuation arm 510 with which the arm checking portion 156 contacts is determined by placing the arm checking portion 156 between the parking actuation arm 510 and the second shifter member 110L (parking gear). It may be provided at a portion of the outer peripheral side surface of the arm 510 that faces the second shifter member 110L.

Next, another embodiment of the drum-type transmission will be described with reference to FIG. In this embodiment, in the parking lock mechanism 500A, the shape and formation position of the arm restraint portion 156A on the speed change operation shaft 150 and the shape and formation position of the engagement hole 517A on the operating arm 510 for parking are shown in FIGS. It is different from the engaging hole 517 and the arm restraining portion 156 of the embodiment described with reference. Since the configuration of other parts is the same as that of the above-described embodiment described with reference to FIGS. 1 to 4, detailed description thereof will be omitted.

In the embodiment shown in FIG. 5, the arm restraint portion 156A and the engagement hole 517A are arranged so that the parking actuation arm 510 is engaged when the drum member 140 is positioned at the parking position (when the shift operating arm 155 is positioned at the parking position P). It is configured to restrict movement toward the unlocked position.

Arm restraint portion 156A is provided on the end surface of one end portion 150a of shift operating shaft 150 and protrudes in the axial direction of shift operating shaft 150 so as to be eccentric with respect to the axis of shift operating shaft 150. . In the present embodiment, the arm checking portion 156A is formed by cutting out a portion of the peripheral wall of the one end portion 150a of the speed change operation shaft 150, and has a substantially fan-shaped columnar shape.

As shown in FIG. 5A, in the parking release state in which the parking operating arm 510 is positioned at the unlocked position, the parking operating arm 510 moves the shift operation arm 155 between the reverse position R and the low speed position L. It is configured so as not to hinder the rotation of the speed change operation shaft 150 (rotational displacement of the arm checking portion 156) when it is rotated.

In this embodiment, the engagement hole 517A of the parking operating arm 510 has the form of a circular through hole with a diameter slightly larger than the shaft diameter of the speed change operation shaft 150. As shown in FIG. When the drum shaft 148 is rotated between the parking position and the reverse position when viewed from the axial direction of the speed change operation shaft 150 (when the speed change operation arm 155 is moved), the inner peripheral wall of the engagement hole 517A is in the parking release state. When the drum shaft 148 is rotated between the reverse position and the low speed position (shift operating arm 155 is rotated between the reverse position R and the low speed position L). As a result, when the shift operating arm 155 is pivotally displaced between the reverse position R and the low speed position L, the arm checking portion 156A is prevented from coming into contact with the inner peripheral wall of the engagement hole 517A. It is possible to prevent an increase in the operating resistance of 155.

As shown in FIG. 5B, in the parking state in which the parking operating arm 510 is positioned at the locked position, the arm checking portion 156A is positioned to restrict movement of the parking operating arm 510 toward the unlocked position. be done. In this embodiment, the engagement hole 517A is located closer to the second shifter member 110L (parking gear) than the position in the parking release state (see FIG. 5A), and the second shifter member 110L of the arm restraint portion 156A is located closer to the second shifter member 110L (parking gear). The end near (parking gear) is arranged close to the inner peripheral wall of the engagement hole 517A when viewed from the axial direction of the speed change operation shaft 150 .

The parking lock mechanism 500A in this embodiment is a lock mechanism that regulates the movement of the parking actuation arm 510 toward the unlocked position when the drum member 140 is in the parking position. mechanism and a lock mechanism by the arm restraint portion 156A. Thus, by having two lock mechanisms provided on separate members, even if one of the lock mechanisms fails, the other lock mechanism can maintain the parking state. Reliability can be improved.

In addition, in the parking lock mechanism 500A, by providing an arm checking portion 156A on the speed change operation shaft 150 interlocked with the drum member 140 and the parking pushing member 530, two lock mechanisms can be operated with one operation system. . That is, it is possible to provide a lock mechanism by the arm checking portion 156A without adding a separate operating system to the operating system for operating the rotation of the drum member 140 and the parking pushing member 530 using the speed change operating shaft 150. , the reliability of the parking lock mechanism 500A can be improved with a simple configuration and low cost.

Furthermore, in the drum-type transmission 1 of the present embodiment, the arm checking portion 156A is formed by cutting the one end portion 150a of the speed change operation shaft 150. Therefore, the speed change operation shaft 150 can be assembled without increasing the number of parts. The arm checking portion 156A can be provided in the drum-type transmission 1, and the reliability of the parking lock mechanism 500A in the drum-type transmission 1 can be improved with a low-cost and compact configuration without causing a significant increase in manufacturing cost.

It should be noted that the arm checking portion 156A may or may not be in contact with the parking operating arm 510 when the parking is locked. That is, the arm restraint portion 156A is provided only when the parking pushing member 530 cannot hold the parking actuating arm 510 at the lock position even though the drum member 140 is at the parking position. It may contact the operating arm 510 to restrict the movement of the parking operating arm 510 to the unlocking position side so that the parking operating arm 510 does not separate from the parking concave/convex portion 112P.

Further, the shape of the arm checking portion 156A is not limited to the substantially fan-shaped columnar shape, and may be other shapes such as a columnar shape. Further, instead of the arm restraint portion 156A formed by cutting out a portion of the shift operating shaft 150, a parking operating arm 510 is attached to one end portion 150a of the shift operating shaft 150 when the drum member 140 is positioned at the parking position. It is also possible to configure the arm checking portion by attaching a separate member that restricts the movement of the arm toward the unlocked position.

Further, the engaging hole 517A in the parking operating arm 510 with which the arm restraint portion 156A contacts is not limited to a circular shape, and may have other shapes such as an L-shaped groove. It may be released on the outer peripheral side surface of 510 . In addition, the arm checking portion 156A contacts the parking operating arm 510 at a position opposite to the second shifter member 110L (parking gear) with respect to the parking operating arm 510. In addition, it may be provided at a portion of the outer peripheral side surface of the parking operating arm 510 opposite to the second shifter member 110L.

Next, the parking lock holding mechanism 700 will be described with reference to FIGS. 3, 6 and 7. FIG. FIG. 6 is a cross-sectional view corresponding to the BB position in FIG. 3, (A) showing the parking release state, and (B) showing the parking state. FIG. 7 is a diagram schematically showing the parking lock holding mechanism 700 and its control system. 3, the second shift idle gear 204 of the shift gear train 200 is shown in cross section along the lock member engaging portion 204a. 6, illustration of the transmission housing 805 and the shift gear chamber cover 806 is omitted.

As shown in FIG. 3, a parking lock holding mechanism 700 is provided on a shift gear chamber cover 806 attached to the transmission housing 805 . The parking lock holding mechanism 700 is configured to lock one of the plurality of shift gears 201, 203, 204, 205 constituting the shift gear train 200 when the drum member 140 is at the parking position (when the shift operation arm 155 is at the parking position P). In this embodiment, the gear lock member 702 is engaged with the lock member engaging portion 204a provided on the second shift idle gear 204 to prohibit the shift gear 204 from rotating.

The parking lock holding mechanism 700 includes a solenoid 701 as an example of an electric actuator that slides the gear lock member 702 in a direction to engage or disengage the lock member engaging portion 204a. Solenoid 701 is attached to the outer surface of shift gear chamber cover 806 so that gear lock member 702 provided at the tip of plunger 703 faces the side surface of second shift idle gear 204 within shift gear chamber 805a. In this embodiment, the tip portion of the plunger 703 itself constitutes the gear lock member 702, but a separate member that can be engaged with the lock member engaging portion 204a is provided at the tip portion of the plunger 703 as a gear lock engagement member. good too.

As shown in FIG. 7, the solenoid 701 is a so-called pull solenoid in which the plunger 703 is retracted (attracted in the direction away from the second shift idle gear 204) when the coil 705 is energized. The elastic force of the elastic member 706 urges the plunger 703 in the protruding direction. That is, the solenoid 701 has a plunger 703 that linearly moves in a direction in which a gear lock member 702 provided at the tip thereof engages or disengages from the lock member engaging portion 204a. A gear lock member 702 provided in the portion is urged in a direction to engage with the lock member engaging portion 204a.

As shown in FIGS. 6 and 7, in the parking lock holding mechanism 700, when the drum member 140 is positioned at the parking position (when the shift operation arm 155 is at the parking position P), the second shift idle of the shift gear train 200 is set. A locking member engaging portion 204a provided on the gear 204 is configured to be positioned on the locus of movement of the gear locking member 702 (on the axis of the plunger 703). When the drum member 140 is in the parking position and the coil 705 of the solenoid 701 is not energized, the gear lock member 702 provided at the tip of the plunger 703 is inserted into and engaged with the lock member engaging portion 204a to engage the second shift idle gear. 204 rotation is prohibited. As a result, the operation of the shift gear train 200 is prohibited, and the rotation of the drum member 140 is also prohibited, so that the parking state by the parking lock mechanism 500 is maintained.

When the drum member 140 is in the operating position other than the parking position, the elastic force of the elastic member 706 presses the gear lock member 702 against a portion of the side surface of the second shift idle gear 204 other than the lock member engagement portion 204a. When the member 140 reaches the parking position, the gear lock member 702 is in a waiting state in which it can be immediately engaged with the lock member engaging portion 204a.

As shown in FIG. 7, the parking lock holding mechanism 700 is operated and controlled by a control device 900 provided in the vehicle on which the drum type transmission 1 is mounted. The control device 900 includes a CPU (Central Processing Unit) that executes various arithmetic processes and controls, a ROM (Read Only Memory) that stores control programs and various data, and a RAM (Random Memory) that temporarily stores control programs and various data. It has a storage device including an access memory, an input interface, and the like.

On the input side of the control device 900, there are a brake sensor 901 for detecting the actuation of a brake operation tool 911 such as a pedal or lever for braking the wheels of the vehicle, and an ignition switch 902 for switching on or off the electric system of the vehicle. and an operating position detection sensor 903 for detecting the operating position of the drum member 140 is electrically connected. The operation position detection sensor 903 is, for example, a sensor that detects the shift position of a shift lever 913 that is provided near the seat of the vehicle and interlocks with the drum member 140, or a potentiometer that detects the rotation angle of the drum shaft 148 of the drum member 140. Consists of sensors, etc.

A solenoid 701 is electrically connected to the output side of the control device 900 . Although not shown in FIG. 7, the controller 900 is electrically connected to various sensors, driving devices, and the like.

The operation of parking lock holding mechanism 700 will be described with reference to FIG. FIG. 8 is a flow chart for explaining the operation of parking lock holding mechanism 700 .

The parking lock holding mechanism 700 is configured such that when the drum member 140 is positioned at an operating position other than the parking position (step S1, No), the solenoid 701 is de-energized regardless of the ON/OFF state of the ignition switch 902. (step S2). At this time, as described above, when the drum member 140 reaches the parking position, the gear lock member 702 is in a waiting state in which it can be immediately engaged with the lock member engaging portion 204a.

When the drum member 140 is in the parking position (the shift lever 913 is in the parking position) (step S1, Yes) and the ignition switch 902 is off (step S3, No), the solenoid 701 of the parking lock holding mechanism 700 Since no power is supplied, coil 705 is in a non-energized state (step S4). At this time, the elastic force of the elastic member 706 engages the gear lock member 702 with the lock member engaging portion 204a, and the parking lock holding mechanism 700 enters an interlock state in which the shift lever 913 is disabled.

When the drum member 140 is in the parking position (step S1, Yes), the ignition switch 902 is on (step S2, Yes), and the brake operating tool 911 is operated (actuated), the control device 900 detects the brake sensor. When the determination is made based on the detection signal of 901 (step S5, Yes), the coil 705 of the solenoid 701 is energized under the control of the control device 900 (step S6). As a result, the plunger 703 is attracted, the gear lock member 702 is pulled out from the lock member engaging portion 204a, and the parking lock holding mechanism 700 enters an interlock released state in which the shift lever 913 can be operated.

When the shift lever 913 is operated to move the drum member 140 to a position other than the parking position after the parking lock holding mechanism 700 has released the interlock (step S1, No), the coil 705 of the solenoid 701 is The power is de-energized under the control of control device 900, and parking lock holding mechanism 700 enters a standby state (step S2).

Also, the solenoid 701 is configured to be able to adjust the projection amount of the plunger 703 by rotating the manual release screw 707 . In a state where the gear lock member 702 of the plunger 703 is inserted into and engaged with the lock member engagement portion 204a of the second shift idle gear 204, by rotating the manual release screw 707 so that the plunger 703 is retracted, the gear lock member is released. 702 and the lock member engaging portion 204a (shift gear locked state) can be released. As a result, even when power cannot be supplied to the solenoid 701 due to, for example, a dead battery, the gear lock member 702 can be manually pulled out from the lock member engaging portion 204a to put the shift gear train 200 in an operable state, and eventually the shift lever can be operated. 913 can be made operational.

In this embodiment, the parking lock holding mechanism 700 is provided on the second shift idle gear 204 of the shift gear train 200 when the drum member 140 is positioned at the parking position (when the shift operation arm 155 is at the parking position P). A gear lock member 702 is engaged with the lock member engaging portion 204a so that the rotation of the second shift idle gear 204 can be prohibited. As a result, it is possible to prevent the vehicle equipped with the drum-type transmission 1 from being released from the parking state due to the unexpected operation of the shift lever 913 provided on the vehicle.

The parking lock holding mechanism 700 also includes a solenoid 701 (an example of an electric actuator) that slides the gear lock member 702 in a direction to engage and disengage the lock member engaging portion 204a. 702 is configured to be biased in the direction of engagement with the lock member engaging portion 204a. As a result, even when power cannot be supplied to the solenoid 701 due to, for example, a dead battery, the gear lock member 702 is engaged with the lock member when the drum member 140 is positioned at the parking position. It is possible to ensure that the operation of the shift gear train 200 is inhibited by engaging the portion 204a.

Furthermore, since the electric actuator is composed of a solenoid 701 having a linearly moving plunger 703, and the gear lock member 702 is provided at the tip of the plunger 703, the parking lock holding mechanism 700 can be realized with a simple and simple configuration. An increase in manufacturing cost can be suppressed.

Further, in the vehicle of this embodiment, when the brake operation tool 911 for braking the wheels is operated, the ignition switch 902 is turned on, and the operation position of the drum member 140 is located at the parking position, the lock member is engaged. A controller 900 is provided for activating solenoid 701 to disengage gear lock member 702 from portion 204a. As a result, the interlocked state of the parking lock holding mechanism 700 (the gear lock member 702 is engaged with the lock member engaging portion 204a and the shift lever 913 of the vehicle cannot be operated) while the vehicle is in a state where the vehicle can travel and is stopped reliably. state) can be released, and movement of the vehicle immediately after the rotation of the drum member 140 from the parking position to another operating position can be prevented.

Next, with reference to FIG. 9, an embodiment of the drum-type transmission 1 using a modified parking lock holding mechanism 700A will be described. In this embodiment, the parking lock holding mechanism 700A has two lock member engaging portions 204b provided on the second shift idle gear 204 of the shift gear train 200, which are non-rotatable relative to the shift idle shaft 202 and axially slidable. The two engaging protrusions 712a of the provided gear lock member 712 are detachably engaged to prohibit the second shift idle gear 204 from rotating.

The parking lock holding mechanism 700 includes a solenoid 711 as an example of an electric actuator that slides the gear lock member 712 in a direction to engage and disengage the lock member engaging portion 204b. The solenoid 711 projects a plunger 713 to move the proximal end of a swinging member 714 swingably around a swinging axis X orthogonal to the sliding direction of the gear lock member 712 (the axial direction of the shift idle shaft 202). The gear lock member 712 connected to the free end portion 714b of the swing member 714 can be moved away from the second shift idle gear 204 by pushing the portion 714a.

A free end portion 714 b of the swinging member 714 is formed in a substantially C-shape so as to sandwich the gear lock member 712 . The inward claws of the free end 714b are engaged to connect them so that they cannot be removed.

Both ends of the shift idle shaft 202 are non-rotatably fixed to the partition wall 805b of the transmission housing 805 and the shift gear chamber cover 806 . That is, the gear lock member 712 provided on the shift idle shaft 202 so as to be non-rotatable and axially slidable is held non-rotatably with respect to the transmission housing 805 and the shift gear chamber cover 806 . An elastic member 716 is externally inserted on the shift idle shaft 202 between the gear lock member 712 and the shift gear chamber cover 806 to bias the gear lock member 712 toward the second shift idle gear 204 side.

The solenoid 711 is a so-called push solenoid in which a plunger 713 protrudes when a coil (not shown) is energized. It is pushed by the proximal end 714a of 714 and is in a retracted state.

When the solenoid 711 is energized, the plunger 713 protrudes and pushes the base end 714a of the rocking member 714 so as to move the gear lock member 712 away from the second shift idle gear 204 against the elastic force of the elastic member 716. is configured as

In the parking lock holding mechanism 700A, when the drum member 140 is positioned at the parking position (when the shift operation arm 155 is at the parking position P), the two lock member engagements provided on the second shift idle gear 204 of the shift gear train 200 are engaged. The joining portion 204b is configured to be positioned on the movement locus of the corresponding engaging projection portion 712a of the gear lock member 712. As shown in FIG. When the drum member 140 is in the parking position and the coil 705 of the solenoid 701 is not energized, the engaging protrusion 712a is inserted into and engaged with the locking member engaging portion 204b, and the rotation of the second shift idle gear 204 is prohibited. be. As a result, the operation of the shift gear train 200 is prohibited, and the rotation of the drum member 140 is also prohibited, so that the parking state by the parking lock mechanism 500 is maintained.

When the drum member 140 is positioned at an operating position other than the parking position, the engagement projection 712a of the gear lock member 712 is disengaged from the lock member engagement portion 204b, and the engagement projection 712a is at the second shift idle position. A portion other than the locking member engaging portion 204b on the side surface of the gear 204 is pressed, and when the drum member 140 is in the parking position, the engaging projection portion 712a is immediately engaged with the locking member engaging portion 204b. It's becoming

The solenoid 711 of the parking lock holding mechanism 700A performs the same operation as the parking lock holding mechanism 700 of the above embodiment according to the flowchart shown in FIG. 8 by the controller 900 shown in FIG.

Also, the solenoid 711 is configured to be able to adjust the projection amount of the plunger 713 by rotating the manual release screw 717 . In a state where the gear lock member 712 of the plunger 713 is inserted into and engaged with the lock member engaging portion 204b, the gear lock member 712 and the lock member are engaged by rotating the manual release screw 717 so that the plunger 713 protrudes further. It is configured to be able to release the engagement (shift gear locked state) with the joining portion 204b. As a result, even when power cannot be supplied to the solenoid 711 due to, for example, a dead battery, the gear lock member 712 can be manually pulled out from the lock member engaging portion 204b to put the shift gear train 200 in an operable state, and eventually the shift lever can be operated. 913 can be made operational.

In this embodiment, the parking lock holding mechanism 700A is provided in the second shift idle gear 204 of the shift gear train 200 when the drum member 140 is positioned at the parking position (when the shift operation arm 155 is at the parking position P). A gear lock member 702 is engaged with the lock member engaging portion 204b so that rotation of the second shift idle gear 204 can be prohibited. As a result, it is possible to prevent the vehicle equipped with the drum-type transmission 1 from being released from the parking state due to the unexpected operation of the shift lever 913 provided on the vehicle.

The parking lock holding mechanism 700A also includes a solenoid 711 (an example of an electric actuator) that slides the gear lock member 712 in a direction to engage and disengage the lock member engaging portion 204b. 712 is configured to urge the engaging protrusion 712a of the locking member engaging portion 204b in the direction of engaging with the locking member engaging portion 204b. As a result, even when power cannot be supplied to the solenoid 711 due to, for example, a dead battery, the gear lock member 712 is engaged with the lock member when the drum member 140 is positioned at the parking position. It is possible to ensure that the operation of the shift gear train 200 is inhibited by engaging the portion 204a.

The present invention is not limited to the above-described embodiments, and can be embodied in various aspects. The configuration of each part is not limited to the illustrated embodiment, and various modifications can be made without departing from the scope of the present invention.

1 drum-type transmission 4 rear wheels 6 front wheels 10, 10H, 10L, 10R transmission gear 100 drum-type transmission operation mechanism 110L second shifter member (an example of a parking gear)
112P Uneven portion for parking 140 Drum member 150 Shift operation shaft 155 Shift operation arm 200 Shift gear train 201 Shift drive gear (shift gear)
203 1st shift idle gear (shift gear)
204 second shift idle gear (shift gear)
204a lock member engaging portion 204b lock member engaging portion 205 shift gear 500, 500A parking lock mechanism 510 parking operating arm 530 parking pushing member 700, 700A parking lock holding mechanism 701 solenoid 702 gear lock member 703 plunger 711 solenoid 712 gear lock member 810 shift shaft 900 control device 901 brake detection sensor 902 ignition switch 903 operation position detection sensor 911 brake operation tool 913 shift lever H high speed position (shift position)
L Low speed position (shift position)
N Neutral position P Parking position R Reverse position (shift position)

Claims (4)

A transmission shaft having a plurality of transmission gears, a drum member for performing a shift operation, and a transmission operation arm for rotating the drum member via a shift gear train,
a parking gear provided on the speed change shaft so as not to rotate relative to it; a parking operating arm displaceable between a locked position engaged with the parking gear and an unlocked position away from the parking gear; a speed change position of the drum member; A drum-type transmission including a parking lock mechanism having a parking push member that pushes the parking operating arm to the lock position in accordance with a rotational movement from a neutral position to a parking position,
A parking lock holding mechanism that, when the drum member is in the parking position, engages a gear lock member with a lock member engaging portion provided on one of the plurality of shift gears constituting the shift gear train to prohibit rotation of the shift gear. A drum type transmission. The parking lock holding mechanism includes an electric actuator that slides the gear lock member in a direction to engage and disengage the lock member engaging portion, and when the electric actuator is de-energized, the gear lock member is engaged with the lock member. 2. A drum-type transmission as claimed in claim 1, configured to be biased toward engaging the portion. 3. The drum-type transmission according to claim 2, wherein said electric actuator comprises a solenoid having a linearly moving plunger, and said gear lock member is provided at a tip of said plunger. A vehicle equipped with the drum-type transmission according to claim 2 or 3,
The gear lock member is engaged with the lock member engaging portion when a brake operation tool for braking the wheels is actuated, an ignition switch is turned on, and a shift lever for operating the shift operation arm is in the parking position. A vehicle comprising a controller for actuating the electric actuator to disengage.

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