JP2009216115A - Vehicular transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular transmission device to which an extra low transmission mechanism can be added without greatly reforming the transmission device. <P>SOLUTION: The extra low transmission mechanism 3b is arranged between an input shaft 10 and an output shaft 11. The mechanism has a first reduction gear train 40 for transmitting the rotation of the input shaft 10 to the side of the output shaft 11 while reducing speed, a second reduction gear train 41 for transmitting the speed-reduced rotation from the side of the output shaft 11 to the side of the input shaft 10 while reducing speed, and a third reduction gear train 42 for transmitting the speed-reduced rotation from the side of the input shaft 10 to the side of the output shaft 11 while reducing speed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicular transmission including a main transmission mechanism having a plurality of forward shift stages and an extra low transmission mechanism having a reduction ratio larger than the maximum reduction ratio of the main transmission mechanism.

  For example, a small truck used for farm work or the like may travel on a steep uphill or rough terrain, and therefore may be provided with an extra low transmission mechanism having a reduction ratio larger than the maximum reduction ratio of the main transmission mechanism. is there.

As a transmission having such an extra low speed change mechanism, for example, in Patent Document 1, an extra low shaft is arranged in parallel with an input shaft, and the extra low shaft meshes with a small gear of the input shaft. A structure has been proposed in which a large gear is disposed and an extra low small gear that meshes with the large gear of the input shaft is disposed. When the shift lever is switched to the extra low range, the rotation of the input shaft is transmitted from the extra low gear to the input shaft and output shaft via the extra low gear, and from the output shaft to the front wheel via the center differential, It is transmitted to the rear wheel.
Japanese Examined Patent Publication No. 6-37923

  By the way, the conventional transmission is provided with a dedicated extra low shaft separately. Therefore, it is necessary to form a protrusion and a supporting boss portion for accommodating the extra low shaft in the transmission case. There is a problem that significant remodeling is required.

  The present invention has been made in view of the above-described conventional situation, and an object thereof is to provide a vehicle transmission device to which an extra low transmission mechanism can be added without significantly modifying the entire transmission case. .

  The invention according to claim 1 is an input shaft to which engine rotation is transmitted, an output shaft disposed in parallel with the input shaft, and disposed between the output shaft and the input shaft, and the rotation of the input shaft. A transmission for a vehicle, comprising: a main transmission mechanism having a plurality of transmission gear trains for transmitting the transmission gear to the output shaft; and an extra low transmission mechanism having a reduction ratio larger than a maximum reduction ratio of the main transmission mechanism. The extra low speed change mechanism is disposed between the input shaft and the output shaft, and the first reduction gear train that reduces and transmits the rotation of the input shaft to the output shaft side is reduced. A second reduction gear train that decelerates and transmits rotation from the output shaft side to the input shaft side, and decelerates the decelerated rotation from the input shaft side to the output shaft. It is characterized by a third reduction gear train reaching.

  According to a second aspect of the present invention, in the vehicle transmission device according to the first aspect, a reverse idler shaft is provided in parallel to the input shaft, and a third reduction gear disposed on the input shaft is disposed on the reverse idler shaft. A first idler gear that meshes with a small reduction gear of the gear train and a second idler gear that meshes with a reverse gear disposed on the output shaft are provided.

  According to the transmission of the first aspect of the invention, the first to third reduction gear trains that reduce the rotation of the input shaft and transmit it to the output shaft are disposed between the input shaft and the output shaft. Therefore, the engine rotation is transmitted to the output shaft while being alternately decelerated between the input shaft and the output shaft.

  Thus, according to the present invention, an extra low speed change mechanism having a large reduction ratio can be realized with a structure in which the input shaft and the output shaft are extended by the arrangement space of the first to third reduction gear trains. As a result, it is possible to eliminate the need for significant modification of the transmission case as compared with a case where a conventional dedicated extra low shaft is separately provided, and it is easy to secure an arrangement space for the first to third reduction gear trains. In particular, the small truck which is the main object of the present invention is suitable because there is a space in the axial direction of the input shaft and the output shaft.

  In the invention of claim 2, since the first idler gear of the reverse idler shaft is engaged with the small reduction gear of the third reduction gear train of the input shaft and the second idler gear is engaged with the reverse gear of the output shaft, The rotation decelerated by the second reduction gear train is further decelerated from the first and second idler gears via the reverse gear and transmitted to the output shaft. This eliminates the need for deceleration between the small reduction gear of the third reduction gear train and the first idler gear, and therefore there is no need to increase the diameter of the first idler gear, and a reverse mechanism is provided in the extra low transmission mechanism. Can be avoided.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 3 are views for explaining a vehicle transmission according to an embodiment of the present invention. FIG. 1 is a sectional view of the transmission, FIG. 2 is a sectional view of an extra low transmission mechanism of the transmission, FIG. 3 is a gear arrangement diagram of the extra low speed change mechanism.

  In the figure, reference numeral 1 denotes an engine unit mounted on a four-wheel drive vehicle such as a small truck. The engine unit 1 has a structure in which a horizontally mounted engine main body 2 mounted with a crankshaft 2a facing in the vehicle width direction and a manual transmission 3 are integrated, and left and right front wheels (non-rotating wheels) It is mounted on the front side of the vehicle from axles 4 and 4 in the figure. Here, the engine unit 1 may be referred to as a “power train” including the engine body 2 and the transmission 3.

  The transmission 3 includes a transmission case 6 that accommodates an input shaft 10 and an output shaft 11 that are mainly arranged coaxially with the crankshaft 2a. The transmission case 6 is coupled to the engine body 2 via a clutch cover 8 in which a clutch mechanism 7 is accommodated.

  The clutch mechanism 7 transmits the rotation of the crankshaft 2a to the input shaft 10 by pressing the pressure plate 7c with a leaf spring 7b against a flywheel 7a attached to the crankshaft 2a, and a clutch pedal (not shown) is By stepping on, the release bearing 7d attached to the input shaft 10 is moved to release the pressure of the leaf spring 7b, thereby blocking the rotation of the crankshaft 2a to the input shaft 10.

  The transmission 3 includes a main transmission mechanism 3a that switches the engine rotation to either one of five forward speeds or one reverse speed, and an extra low transmission mechanism 3b that has a reduction ratio larger than the maximum reduction ratio of the main transmission mechanism 3a. ing.

  The main transmission mechanism 3a includes the input shaft 10 to which engine rotation is transmitted via the clutch mechanism 7, the output shaft 11 arranged in parallel with the input shaft 10, the output shaft 11 and the input shaft. The transmission gear train is disposed between the shaft 10 and transmits the rotation of the input shaft 10 to the output shaft 11 at a predetermined speed. Has the following structure.

  The input shaft 10 is integrally formed with a first speed drive gear 10a, a reverse drive gear 10b and a second speed drive gear 10c in the axial direction from the crankshaft side, and further, a third speed drive gear 13, a fourth speed drive gear 14 and 5 The high speed drive gear 15 is rotatably mounted on each.

  On the other hand, the output shaft 11 has a first-speed driven gear 16 that meshes with the first-speed drive gear 10a, a reverse-driven gear 17 that can mesh with the river drive gear 10b with a reverse intermediate gear 12 interposed therebetween, and the second-speed drive gear. A second speed driven gear 18 that meshes with 10c is rotatably mounted, and further meshes with a third speed driven gear 19 that meshes with the third speed drive gear 13, a fourth speed driven gear 20 that meshes with the fourth speed drive gear 14, and a fifth drive gear 15. The five-speed driven gears 21 are splined to each other.

  The sleeves 24 and 25 are movable in the axial direction between the 3rd speed drive gear 13 and the 4th speed drive gear 14 of the input shaft 10 and the outside of the 5th speed drive gear 15 through the synchronizer rings 22 and 23, respectively. It is attached to.

  A sleeve 27 is mounted between the first-speed driven gear 16 and the second-speed driven gear 18 of the output shaft 11 via a synchronizer ring 26 so as to be movable in the axial direction.

  Each sleeve 24, 25, 27 is engaged with a shift fork connected to a shift lever (not shown). By swinging the shift lever back and forth and from side to side from the neutral position, the shift lever is switched to one of the five forward speeds and one reverse speed.

  An output gear 11 a is integrally formed at the crankshaft side end portion of the output shaft 11, and the output gear 11 a meshes with a front ring gear 33 a of the differential gear mechanism 33. Left and right front wheel drive shafts 34 and 34 are splined to the differential gear mechanism 33. The left and right axles 4 are connected to the left and right front wheel drive shafts 34 via a universal joint (not shown).

  A rear wheel ring gear 36 is integrally attached to the front end ring gear 33a. The rear wheel ring gear 36 is connected to the left and right rear wheels via a rear wheel drive shaft 37, an intermediate drive shaft 38, and a differential gear mechanism (not shown). Thereby, the engine rotation after the shift is transmitted from the output shaft 11 to the front and rear wheels via the front wheel ring gear 33a and the rear wheel ring gear 36.

  The extra low speed change mechanism 3 b is configured to decelerate the rotation of the input shaft 10 in three stages and transmit it to the output shaft 11. Specifically, the first reduction gear train 40 that transmits the rotation of the input shaft 10 by decelerating the rotation to the output shaft 11 side, and the decelerated rotation is decelerated from the output 11 axis side to the input shaft 10 side. A second reduction gear train 41 for transmission and a third reduction gear train 42 for reducing and transmitting the reduced rotation from the input shaft 10 side to the output shaft 11 are provided.

  The input shaft 10 and the output shaft 11 are extended in the axial direction by the arrangement space of the first to third reduction gear trains 40 to 42.

  The first reduction gear train 40 includes a first reduction small gear 40a splined to rotate together with the input shaft 10 and a first reduction gear rotatably mounted on the output shaft 11 via a needle bearing 40c. And a large gear 40b.

  The second reduction gear train 41 is rotatably attached to the input shaft 10 via a needle bearing 41c, and a second reduction small gear 41a integrally formed to rotate together with the first reduction large gear 40b. And a second reduction large gear 41b.

  The third reduction gear train 42 is rotatably attached to the output shaft 11 via a needle bearing 42c, and a third reduction small gear 42a integrally formed to rotate together with the second reduction large gear 41b. And a third reduction large gear 42b.

  A reverse idler shaft 45 is disposed in parallel to the input shaft 10 on the vehicle front side of the input shaft 10.

  A first idler gear 46 a and a second idler gear 46 b having the same number of teeth are rotatably mounted on the reverse idler shaft 45 via needle bearings 47 and 47. The first and second idler gears 46a and 46b are integrally formed.

  A reverse gear 48 is rotatably mounted on the outer end portion of the third reduction large gear 42 b of the output shaft 11 via a needle bearing 49.

  The first idler gear 46 a meshes with the third reduction small gear 42 a of the third reduction gear train 42, and the second idler gear 46 b meshes with the reverse gear 48.

  A forward / reverse switching sleeve 51 is mounted between the third reduction large gear 42b of the output shaft 11 and the reverse gear 48 so as to be movable in the axial direction with a synchronizer ring 50 interposed therebetween. A shift fork 52 connected to the aforementioned shift lever is engaged with the forward / reverse switching sleeve 51.

  When the shift lever is in the neutral position or at any gear position of the main transmission mechanism 3a, the first to third reduction gear trains 40 to 42, the first and second idler gears 46a and 46b, and the reverse gear 48 are idling. .

  When the shift lever is switched to the extra low advance position, the switching sleeve 51 moves to the right in the axial direction, and the third reduction large gear 42 b is fixed to the output shaft 11. Then, the rotation of the input shaft 10 is decelerated and transmitted to the output shaft 11 through the first to third reduction gear trains 40 to 42 in three stages, and the rotation of the output shaft 11 is transmitted from the output gear 11a to the front wheel ring gear 33a. , Are transmitted to the front and rear wheels via the rear ring gear 36.

  When the shift lever is switched to the extra low reverse position, the switching sleeve 51 moves to the left side and the reverse gear 48 is fixed to the output shaft 11. Then, the rotation of the input shaft 10 is transmitted to the first idler gear 46a through the small gears 42a of the first, second reduction gear trains 40, 41 and the third reduction gear train 42, and from the second idler gear 46b to the reverse gear 48. Is further decelerated and transmitted to the output shaft 11 in the reverse rotation direction. The reverse rotation of the output shaft 11 is transmitted from the output gear 11a to the front and rear wheels.

  The transmission case 6 includes an axially divided case body 6 a that rotatably supports the input shaft 10 and the output shaft 11 with the clutch cover 8, and an extension of the input shaft 10 and the output shaft 11. A mission cover 6c covering the portion.

  The first to third reduction gear trains 40 to 42, the reverse idler shaft 45 and the river gear 48 are accommodated in the mission cover 6c, and the reverse idler shaft 45 is supported by the mission cover 6c and the case body 6a so as not to rotate. Has been. The outer ends of the input shaft 10 and the output shaft 11 are rotatably supported by the mission cover 6c.

  Thus, according to the extra low speed change mechanism 3b of the present embodiment, the first to third decelerations that decelerate the rotation of the input shaft 10 and transmit it to the output shaft 11 to the input shaft 10 and the output shaft 11. Since the gear trains 40 to 42 are arranged, the engine rotation is transmitted to the output shaft 11 while being alternately decelerated between the input shaft 10 and the output shaft 11.

  As described above, in the present embodiment, the extra low speed change mechanism 3b having a large reduction ratio can be realized with a structure in which the input shaft 10 and the output shaft 11 are extended by the arrangement space of the reduction gear trains 40 to 42. . As a result, it is possible to eliminate the need for significant modification of the transmission case as compared with a case where a conventional dedicated extra low shaft is separately provided, and to suppress an increase in cost. That is, in the present embodiment, only the mission cover 6c of the mission case 6 needs to be changed. Further, since the extra low mechanism is realized by extending the input shaft and the like in the axial direction, it is easy to secure the arrangement space.

  Further, since the reverse idler shaft 45 is accommodated in the mission cover 6c, it is not necessary to change the case main body 6a side, and from this point, an increase in cost can be suppressed.

  In the present embodiment, the first idler gear 46 a of the reverse idler shaft 45 is engaged with the third reduction small gear 42 a of the third reduction gear train 42, and the second idler gear 46 b is engaged with the reverse gear 48 of the output shaft 11. Therefore, the first and second reduction gear trains 40 and 41 and the second idler gear 46b and the reverse gear 48 can be decelerated, and the first reverse gear 46a can be decelerated. As a result, the first idler gear 46a and the second idler gear 46c can be reduced, and an increase in the size of the transmission case 6 can be avoided.

  In the above-described embodiment, the case where the extra low speed change mechanism 3b includes both forward and reverse movements has been described. However, in the present invention, as shown in FIG. Also good. In this case, by providing the input shaft 10 and the output shaft 11 with the first to third reduction gear trains 40 to 42, the mission cover 6c 'of the mission case 6 can be reduced, and the engine unit can be mounted on the vehicle body. Even when mounting on the front side, it is easy to secure the arrangement space.

  In the above-described embodiment, the case where the engine unit 1 is mounted on the front side of the front axle 4 is described as an example. However, the engine unit of the present invention is a vehicle mounted on the rear side of the front axle or the rear axle. It can also be applied to a vehicle mounted on the front side or rear side of the vehicle. In particular, when the engine unit is mounted on the rear side, there is no restriction on the steering angle as compared with the front side. Therefore, it is easy to secure a mounting space even when the input shaft and the output shaft are extended.

It is sectional drawing of the transmission for vehicles by one Embodiment of this invention. It is sectional drawing of the extra low transmission mechanism of the said transmission. It is a gear arrangement diagram of the extra low speed change mechanism. It is sectional drawing which shows the modification of the extra low transmission mechanism of the said embodiment.

Explanation of symbols

3 Transmission 3a Main transmission mechanism 3b Extra low transmission mechanism 10 Input shaft 11 Output shaft 40 First reduction gear train 41 Second reduction gear train 42 Third reduction gear train 42a Third reduction small gear 45 Reverse idler shaft 46a First Idler gear 46b Second idler gear 48 Reverse gear

Claims (2)

An input shaft to which engine rotation is transmitted, an output shaft arranged in parallel to the input shaft, and disposed between the output shaft and the input shaft, and transmits the rotation of the input shaft to the output shaft. A main transmission mechanism having a plurality of transmission gear trains,
A vehicular transmission including an extra low transmission mechanism having a reduction ratio larger than a maximum reduction ratio of the main transmission mechanism,
The extra low speed change mechanism is disposed between the input shaft and the output shaft, and a first reduction gear train that transmits the rotation of the input shaft by decelerating to the output shaft side;
A second reduction gear train for reducing and transmitting the reduced rotation from the output shaft side to the input shaft side;
And a third reduction gear train for transmitting the reduced rotation from the input shaft side to the output shaft. The vehicle transmission device according to claim 1,
A reverse idler shaft is provided in parallel to the input shaft,
A first idler gear that meshes with a reverse small gear of a third reduction gear train disposed on the input shaft, and a second idler gear that meshes with a reverse gear disposed on the output shaft. A transmission for a vehicle characterized by being provided.

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