JPH064105Y2 - Multi-speed transmission - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial field of application The present invention is a traveling vehicle, in which a hydraulic clutch device and an overrunning clutch are arranged side by side on one axis, so that a single hydraulic clutch can increase and decrease the height. The present invention relates to a multi-stage speed change device capable of changing gears without operating a clutch pedal.

(B) Prior Art Conventionally, there has been known a multi-stage transmission device in which a hydraulic clutch is provided for each gear stage and gear shifting is possible without operating a main clutch pedal.

For example, it is as in Japanese Utility Model Laid-Open No. 51-124556.

However, in the conventional technique, a hydraulic clutch is required for each shift speed, and the cost is high.

(C) Problems to be Solved by the Invention In the present invention, by providing a hydraulic clutch and an overrunning clutch on the speed change shaft, it is possible to perform high and low two-speed gear shift on the shaft. A multi-stage transmission is configured by connecting and increasing units for high and low two-stage shifts.

With this configuration, it is possible to interpose the hydraulic clutch for half of the gear shift stage and substitute the overrunning clutch for the latter half, simplifying the configuration and reducing the cost. is there.

However, in a transmission using a hydraulic clutch and an overrunning clutch, the following problems occur due to the nature of the overrunning clutch.

That is, when the vehicle is traveling in a power transmission state with the hydraulic clutch disengaged and the overrunning clutch, if the vehicle tries to descend on a steep slope, the driving speed from the wheel side due to the weight of the aircraft will be less than that from the engine side. When the driving speed is higher than the driving speed, the engagement state due to the driving force from the wheel side is released by the idling of the overrunning clutch and becomes free rotation, and the engine braking state does not occur.

Therefore, if you do not step on the running brake quickly, there is a danger of a serious accident.

In the present invention, an engine braking clutch is provided in parallel with the overrunning clutch in order to solve the problem that the engine brake is not applied due to the installation of the overrunning clutch.

(D) Means for Solving the Problems The purpose of the present invention is as described above, and the configuration for achieving the purpose will be described below.

A pair of high and low gears are arranged between the two shafts, a high speed side loose fitting gear on the lower shaft has a high speed side hydraulic clutch, and a low speed side loose fitting gear has a low speed overrunning clutch. , A low-speed side free-fitting gear having a configuration capable of shifting to a high speed for transmitting power through the high-speed side hydraulic clutch and a low speed for transmitting power through the low-speed side overrunning clutch by connecting / disconnecting the high-speed side hydraulic clutch. In the power transmission section between the shaft and the shaft, a power transmission system by the low speed side overrunning clutch and a power transmission system by the engine braking clutch are arranged in parallel. The hydraulic cylinders of both clutches are made to communicate with each other in order to interlock with "disconnect / disconnect" and reversely "disconnect / disconnect".

Further, the capacity of the hydraulic cylinder of the engine braking clutch is smaller than the capacity of the hydraulic cylinder of the high speed side hydraulic clutch.

(E) Embodiment The purpose and construction of the present invention are as described above. Next, the construction of the embodiment shown in the accompanying drawings will be described.

FIG. 1 is an overall side view of a rice transplanter equipped with the multistage transmission of the present invention, FIG. 2 is a side sectional view of a mission case portion of the rice transplanter, and FIG. 3 is only a main part of the transmission. FIG. 4 is a power transmission diagram showing another embodiment in which the arrangements of the hydraulic clutch and the overrunning clutch are different, and FIG. 5 is a hydraulic circuit diagram of the multi-stage transmission of the present invention.

Referring to FIG. 1, the overall structure of a rice transplanter equipped with the multi-speed transmission of the present invention will be described.

Engine E on the airframe supported by front wheels 31 and rear wheels 32
Is mounted, the crankshaft of the engine E is extended, and power is transmitted to the main clutch device B.

The power after being engaged and disengaged by the main clutch device B is input to the mission case M. In the present embodiment, the mission case M includes the front mission case M1, the center plate M2, and the rear mission case M3. Of 3
It is composed by combining people.

In the mission case M, the power after shifting is transmitted to the rear wheel 32 by the swing case 33 by the multi-stage transmission of the present invention, and the front wheel 31 is driven through the front wheel power transmission shaft 35.

Further, power is transmitted to the planting apparatus R via the joint shaft 34.

A hydraulic pump P for sending pressure oil for the multi-stage transmission is arranged on the rear surface of the center plate M2, and a shift lever 9 for operating a shift control valve V for controlling the multi-stage transmission is provided on the side of the seat. Are arranged.

Next, referring to FIGS. 2 and 3, the specific structure of the multi-stage transmission of the present invention will be described.

The input shaft 3, the first speed-change shaft 1 and the second speed-change shaft 2 are arranged so as to span the front mission case M1 and the center plate M2 in the mission case M.

The power of the engine E is transmitted to the main clutch device B, and the power after being disengaged by the main clutch device B is input to the input shaft 3
Have been transmitted to.

The fixed gears 10 and 11 on the input shaft 3 and the first transmission shaft 1
A pair of high and low gear trains is formed between the input shaft 3 and the first speed-change shaft 1 by the loosely fitting gears 12 and 17 on the top.

The constant mesh gear train of the fixed gear 10 and the loose fitting gear 12 is a high speed gear train, and the constant mesh gear train of the fixed gear 11 and the loose fitting gear 17 is a low speed gear train.

The loose fit gear 12 is configured to be engaged with the first speed change shaft 1 via the high speed side hydraulic clutch C1.
7 is via the low speed side overrunning clutch A1,
It is configured to be engageable with the first transmission shaft 1.

Further, in the loose fitting gear 17, an engine braking clutch D1 having a smaller capacity than the high speed side hydraulic clutch C1 is provided in parallel with the low speed side overrunning clutch A1.

The hydraulic oil sent to the hydraulic cylinder 5 of the engine braking clutch D1 is branched from the hydraulic oil sent to the hydraulic cylinder 4 of the high speed hydraulic clutch C1 to be sent. The engine braking clutch D1 is configured so as to move in the opposite direction of the "connection / disconnection" with respect to the "disconnection / connection" of C1.

In the engine braking clutch D1, a claw portion is formed at the housing end thereof so that the claw portion of the loose fitting gear 17 can be connected and disconnected, and when pressure oil is not fed into the hydraulic cylinder 5, it is loosely fitted. The urging spring 38 urges the gear 17 and the first transmission shaft 1 in the engaging direction.

Further, the housing is made non-rotatable with respect to the first transmission shaft 1 by a ball-shaped key stop member 9 and can be slid smoothly in the clutch disengagement direction.

The relationship between the capacity of the high speed side hydraulic clutch C1 and the capacity of the engine braking clutch D1 is set such that the hydraulic cylinder 4 is larger than the hydraulic cylinder 5.

Next, the transmission device between the first speed change shaft 1 and the second speed change shaft 2 will be described.

A high / low speed change device including a hydraulic clutch and an overrunning clutch is similarly interposed between the first speed change shaft 1 and the second speed change shaft 2.

That is, the constantly meshed gear train of the fixed gear 18 on the first speed change shaft 1 and the loose fit gear 19 on the second speed change shaft 2 is the high speed gear train.

Further, the constant meshing connection between the fixed gear 13 on the first speed change shaft 1 and the loose fitting gear 20 on the second speed change shaft 2 is the low speed gear change.

The free-fitting gear 19 of the high-speed gear train is configured to be engageable with the second transmission shaft 2 via the high-speed hydraulic clutch C2, and the free-fitting gear 20 of the low-speed gear train operates the low-speed overrunning clutch A2. It is configured to be engageable with the second transmission shaft 2 via the.

Further, in parallel with the low speed side overrunning clutch A2, the loosely fitted gear 20 can be engaged with the second speed change shaft 2 through the engine braking clutch D2.

The same pressure oil is branched and fed to the hydraulic cylinder 8 of the engine braking clutch D2 and the hydraulic cylinder 6 of the high speed side hydraulic clutch C2 by the shift control valve V to connect and disconnect the high speed side hydraulic clutch C2. On the other hand, the engine braking clutch D2 acts in the direction opposite to the disconnected state.

The high speed side hydraulic clutch C2 and the engine braking clutch D2
The capacity relationship of the hydraulic cylinder 6 is larger than that of the hydraulic cylinder 8.

Further, the input shaft 3, the first speed change shaft 1 and the second speed change shaft 2 are installed in the front transmission case M1.

In the present invention, the extension shaft 14 and the PTO are installed in the space defined by the center plate M2 and the rear mission case M3.
A shaft 15, a counter shaft 16, and a wheel drive shaft 7 are arranged.

First, in the present embodiment, the second speed-changing shaft 2 is the final speed-changing shaft of the multi-speed transmission of the present invention, and this is the output shaft. Further, it is inserted from the front mission case M1 into the rear mission case M3, and the insertion portion is connected to the extension shaft 14 by a coupling.

Reverse-movement loosely fitted gears 21 and 22 are provided on the coupling portion.
Is loosely fitted, and the fixed gear 23 is mounted on the extension shaft 14.
Is fixed.

Power is transmitted from the fixed gear 23 to the forward first speed fixed gear 26 on the PTO shaft 15.

Further, on the PTO shaft 15, another forward second speed fixed gear 25
And the reverse speed fixed gear 24 is fixed. The reverse speed fixed gear 24 meshes with the reverse play loosely fitted gear 21.

Sliding gears 27 and 28 are slidable back and forth on the counter shaft 16.
By sliding 28 back and forth to 3 positions,
Three speeds are available: high speed, second forward speed, and reverse speed.

The first forward speed is obtained by the sliding gear 28 meshing with the first forward fixed gear 26, and the second forward speed is obtained by the sliding gear 27 meshing with the second forward fixed gear 25.

The reverse speed is obtained by the sliding gear 27 meshing with the reverse play loosely fitted gear 22.

The PTO shaft 15 is extended rearward and is connected to the joint shaft 34 of FIG. 1 to drive the planting apparatus R.

The wheel drive shaft 7 is extended rearward to drive the rear wheel 32 via the swing case 33. Further, the wheel drive shaft 7 is projected forward and drives the front wheel 31 via the front wheel power transmission shaft 35.

A hydraulic pump P is fixed to the rear surface of the center plate M2 at a portion exposed above the rear mission case M3, and is driven by a rearward extension of the input shaft 3, that is, a driven shaft of the main clutch device B.

Next, the embodiment shown in FIG. 4 will be described.

This embodiment is different from the embodiment shown in FIGS. 2 and 3 in that the positions of the high speed side hydraulic clutch C2 and the engine braking clutch D2 are reversed in the front-rear direction.

This is because one unit on the first speed change shaft 1 is capable of high and low speed change, and one unit on the second speed change shaft 2 is capable of high and low speed change, and there is a hydraulic clutch on each shaft. Since the overrunning clutch enables high and low speed shifting, which of high and low is to be arranged in the front and back is only decided in relation to the arrangement of the fixed gear on the shaft of the upper stage, and it is not possible to set it over the hydraulic clutch of the upper stage. This is because the position of the running clutch is not restricted.

In the embodiment shown in FIGS. 2 and 3, the clutch connecting / disconnecting portion of the engine braking clutch D1 and the engine braking clutch D2 is a dog clutch constituted by pawls.
The embodiment of FIG. 4 is different in that it is constituted by a friction plate type clutch.

The engine braking clutches D1 and D2 may be of a claw type or a friction plate type.

The engine braking clutches D1 and D2 in FIGS. 2 and 3 are shown in the disengaged position in the upper half of the transmission shafts 1 and 2 and in the engaged position in the lower half, but are actually selective. It is the one that makes either movement.

Next, referring to FIGS. 4 and 5, the hydraulic circuit for operating the multi-stage transmission of the present invention will be described.

Pressure oil is discharged by a hydraulic pump P provided at a rear end protruding portion of the input shaft 3, and the pressure oil of the hydraulic pump P is sent to a main relief valve L2 and a shift control valve V.

The return oil from each of the high speed side hydraulic clutches C1 and C2 is retained by the low pressure relief valve L1 and the transmission shaft 1 of FIG.
・ Each hydraulic clutch C1 by the lubricating oil passage 1 drilled in 2 ・
Used as lubricating oil for C2 and overrunning clutches A1 and A2.

The shift control valve V is constantly biased by the biasing spring 36, and is biased in the first speed direction.

The first speed of the speed change control valve V is the first speed change shaft 1 side.
This is the case where the pressure oil is not sent to either of the second speed-change shaft 2 side.

The second speed is a case where oil is sent to the first speed change shaft 1 side but not to the second speed change shaft 2 side.

In the third speed, the oil is not sent to the first speed change shaft 1 side, but the second speed change shaft 2
This is the case when sending oil only to the side.

The fourth speed is a case where oil is fed to either the first speed change shaft 1 side or the second speed change shaft 2 side.

(F) Action of the Invention The present invention is configured as described above. Next, it will be described how each of the hydraulic clutch, the overrunning clutch, and the engine braking clutch acts by switching the shift control valve V. .

In the case of the first speed, the shift control valve V is in the center open state, the pressure oil from the hydraulic pump P is not supplied to either, and the state of FIG. 2 (the first of FIG.
This is the state of the lower half of the speed change shaft 1 and the lower half of the second speed change shaft 2.

That is, on the first speed change shaft 1, since the hydraulic oil is not sent to the hydraulic cylinder 4, the high speed side hydraulic clutch C1 is in the disengaged state, and similarly, the hydraulic oil is not sent to the hydraulic cylinder 5, so that the engine braking clutch D1 is It is pushed by the urging spring 38 to connect the loosely fitted gear 17 and the first transmission shaft 1.

Further, since the high speed side hydraulic clutch C1 is not connected to the first speed change shaft 1, the rotation of the high speed gear train constituted by the fixed gear 10 and the loose fitting gear 12 is not transmitted to the first speed change shaft 1. On the contrary, the rotation of the low speed gear train of the fixed gear 11 and the loose fitting gear 17 is transmitted to the first transmission shaft 1 via the low speed side overrunning clutch A1 which is in the engaged state when the power is transmitted from the loose fitting gear 17 side. Power is being transmitted.

Similarly, the high-speed hydraulic clutch C2 on the second speed change shaft 2 is in the disengaged state, and the engine braking clutch D2 is the biasing spring 3
9 is engaged. Since the high speed gear train does not transmit power, the low speed rotation is transmitted to the second speed change shaft 2 by the low speed side overrunning clutch A2 which is engaged when the power is transmitted from the loose fitting gear 20 side.
The first speed is the lower speed of the first speed change shaft 1 side × the lower speed of the second speed change shaft 2 side.

Since the engine braking clutches D1 and D2 in parallel with the low speed side overrunning clutches A1 and A2 are also in the engaged state, power can be transmitted also from the engine braking clutches D1 and D2, but the main power transmission is the low speed side overrunning. It is performed by the clutches A1 and A2.

The engine braking clutches D1 and D2 are necessary when the power on the wheel side is transmitted to the engine side, as in the case where the engine brake is applied or the battery needs to be struck when the battery is dead.

The reason for interposing the engine braking clutches D1 and D2 is as follows.
When power is transmitted from the engine side to the wheel side through the low speed side overrunning clutches A1 and A2 on the first speed change shaft 1 and the second speed change shaft 2, the axles are rotated more than the rotation from the engine side. When fast rotation is transmitted from the opposite side, the low speed side overrunning clutch A1 ・ A
No. 2 is in a locked state in power transmission from the loose fitting gear side, but is in a freely rotatable state from the shaft side.

Therefore, when lowering the vehicle from the bed of the truck along the walking board or when descending a steep downhill, the speed of the descent force due to the inertial force of the airframe becomes faster than the power from the engine. However, there is a dangerous state that does not occur in the case of a structure in which gears and clutches are engaged with each other to transmit power.

That is, since the descending speed from the wheel side freely rotates in the low speed side overrunning clutches A1 and A2,
The condition of the engine brake is not applied, and if the running brake is not applied quickly, it will suddenly descend and cause a serious accident.

Therefore, this low speed side overrunning clutch A1 ・ A2
The problem that the drive rotation from the wheel side is freely released in the part of
Is disposed in parallel with the low speed side overrunning clutches A1 and A2.

In addition, the engine braking clutches D1 and D2 also work effectively when the engine is struck when the battery is dead.

Further, the engine braking clutches D1 and D2 are
Since it does not transmit the large horsepower on the high side, and is unlikely to operate at all times, the high speed side hydraulic clutch C
It is possible to construct a clutch having a smaller capacity than that of the 1 / C2.

Next, in the second speed, pressure oil is sent to the first speed-change shaft 1 side, and the high-speed hydraulic clutch C1 is engaged. At the same time, the engine braking clutch D1 is released, so that the double meshing state does not occur. (State of the upper half portion of the first transmission shaft 1 in FIG. 3) At this time, the high-speed hydraulic clutch C1 has a larger capacity and the engine braking clutch D1 has a smaller capacity. The hydraulic cylinder 5 of the braking clutch D1 is configured to be charged and released first. Next, the order in which the high speed side hydraulic clutch C1 is engaged is maintained, so that the double meshing state does not occur.

By joining the high speed side hydraulic clutch C1, the first
The speed change shaft 1 rotates at a high speed, and the low speed side overrunning clutch A1 interposed in the loosely fitted gear 17 rotates freely at a higher speed on the shaft side, so that the first speed change shaft 1 is rotated. And the loose fitting gear 17 perform different rotations, and the low-speed side overrunning clutch A1
Will be absorbed.

The oil is not sent to the second speed-changing shaft 2 side (the lower half of the second speed-changing shaft 2 in FIG. 3), and the second speed-changing shaft 2
Then, since the high speed hydraulic clutch C2 is disengaged and the low speed overrunning clutch A2 engages with the shaft from the side of the loose fitting gear 20, the second speed changing shaft 2 is driven.

Therefore, the second speed is obtained by the high speed of the first speed change shaft 1 side × the low speed of the second speed change shaft 2 side.

On the contrary, in the third speed, the oil is not sent to the first speed change shaft 1 side, but is sent to the second speed change shaft 2 side.

Therefore, the first speed change shaft 1 side is made low speed by the low speed side overrunning clutch A1, the second speed change shaft 2 side is made high speed by the high speed side hydraulic clutch C2, and the third speed is obtained by applying. (The state of the lower half of the first speed change shaft 1 and the upper half of the second speed change shaft 2 in FIG. 3) In the fourth speed, pressure oil is sent to both the first speed change shaft 1 and the second speed change shaft 2. Therefore, the first speed change shaft 1 becomes high speed by the high speed side hydraulic clutch C1, and the second speed change shaft 2 also becomes high speed side hydraulic clutch C2.
As a result, the speed increases to 4th speed. (The state of the upper half of the first speed change shaft 1 and the upper half of the second speed change shaft 2 in FIG. 3) (g) Effect of the invention Since the invention is configured as described above, the following effects can be obtained. It is a thing.

Firstly, in a device in which a hydraulic clutch and an overrunning clutch are arranged on one axis and a high / low shift is performed by connecting / disconnecting the hydraulic clutch, when traveling down a steep slope while traveling in a power transmission state by the overrunning clutch. In addition, when the driving speed from the wheels due to the body weight of the machine exceeds the driving speed from the engine E, the overrunning clutch does not spin and the engine braking is not applied to the driving on the wheel side. There is a danger of an accident if the running brake is not applied to the sword, but in the present invention, since the engine braking clutch is arranged in parallel with the overrunning clutch to transmit power,
Even when the vehicle steeply descends, the engine brake is applied via the engine braking clutch, so that the dangerous state can be eliminated.

Secondly, since the capacity of the hydraulic cylinder of the high speed side hydraulic clutch is set to be larger than the capacity of the hydraulic cylinder 5 of the engine braking clutch, even when both cylinders are communicated and pressure oil is sent. , The order in which the engine braking clutch side is first filled with pressure oil first, the engine braking clutch is disengaged, and then the high speed side hydraulic clutch is gradually engaged is ensured, so that power transmission is performed simultaneously by both systems. It was possible to eliminate the double meshing condition.

Thirdly, when the high speed hydraulic clutch C1 is engaged and the engine E is stopped while descending a steep slope, the pressure oil from the hydraulic pump P is stopped, so the high speed hydraulic clutch C1 is engaged. Is stopped and the engine braking clutch is not locked to the overrunning clutch, so the state of engine braking does not occur. However, when the pressure in the engine braking clutch drops, the urging spring 38 automatically Since the engine braking clutch D1 is engaged and the engine braking state is created, the safety is improved.

Fourth, depending on the hydraulic clutch or the overrunning clutch, the driving force of the wheels may be applied to the engine E even when the battery is exhausted and the engine is started by bumping.
Engine braking clutch D1
By engaging with, it is possible to strike.

[Brief description of drawings]

FIG. 1 is an overall side view of a rice transplanter equipped with the multistage transmission of the present invention, FIG. 2 is a side sectional view of a mission case portion of the rice transplanter, and FIG. 3 is only a main part of the transmission. FIG. 4 is a power transmission diagram showing another embodiment in which the arrangements of the hydraulic clutch and the overrunning clutch are different, and FIG. 5 is a hydraulic circuit diagram of the multi-stage transmission of the present invention. A1, A2 ... Low speed overrunning clutch C1, C2 ... High speed hydraulic clutch D1, D2 ... Engine braking clutch V ... Shift control valve 1 ... First shift shaft 2 ... Second shift shaft 3 ... Input shaft

Claims (2)

[Scope of utility model registration request] 1. A pair of high and low gear trains are arranged between two shafts, a high speed side hydraulic clutch on the lower shaft is provided with a high speed side hydraulic clutch, and a low speed side loosely fitted gear has a low speed side overrunning. A high speed in which power is transmitted through the high speed side hydraulic clutch by connecting and disconnecting the high speed side hydraulic clutch through a clutch.
In the structure capable of shifting to a low speed in which power is transmitted through the low speed side overrunning clutch, the power transmission part between the low speed side loosely fitted gear and the shaft has a power transmission system using the low speed side overrunning clutch and an engine. The power transmission system by the braking clutch is arranged in parallel, and the connection / disconnection of the engine braking clutch is interlocked with the “disconnection / disconnection” of the high-speed side hydraulic clutch, and the hydraulic cylinders of both clutches are connected in reverse to “disconnect / disconnect”. A multistage transmission characterized by being communicated. 2. A multi-stage transmission according to claim 1, wherein the capacity of the hydraulic cylinder of the engine braking clutch is smaller than the capacity of the hydraulic cylinder of the high speed side hydraulic clutch.