JPH02256957A - Transmission of working vehicle - Google Patents

Abstract

PURPOSE:To decrease a change of speed of a working vehicle by connecting a main transmission to a subtransmission in a series condition and providing a control means automatically actuating a main speed change actuator at specific time. CONSTITUTION:A main transmission 2, possible to obtain a speed change steplessly, and a stepped subtransmission 8, changing a speed in two or more steps, are connected in a series condition. A main speed change actuator 49, automatically controlling the main transmission 2, and a subspeed change control detecting means S2, detecting a select control of the subtransmission 8, are provided. A control means 100, which automatically actuates to a deceleration side the main speed change actuator 49 so as to reduce a car speed when the subtransmission 8 is controlled to an acceleration side being based on information of the subspeed change control detecting means S2, is provided. Thus, a change of speed is reduced in a working vehicle even when the subtransmission is controlled to the acceleration side.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a work vehicle in which a main transmission that can shift continuously and a sub-transmission that can shift in multiple stages are connected in series. The present invention relates to a transmission.

[Conventional technology]

Conventionally, in the above-mentioned transmission system for a work vehicle of this type, the speed change of the main transmission device and the speed change of the auxiliary transmission device have been carried out independently.

[Problem to be solved by the invention]

If the shifting of the main transmission and the shifting of the auxiliary transmission are performed independently, since the auxiliary transmission is a stepped type, especially when the auxiliary transmission is shifted to the speed increasing side without decelerating the main transmission. This has the disadvantage that the vehicle speed suddenly increases, as shown by the broken line in FIG.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to prevent the vehicle speed from being suddenly increased even when the auxiliary transmission is shifted to the speed increasing side.

[Means to solve the problem]

The transmission device for a work vehicle according to the present invention is one in which a main transmission device that can shift continuously and a sub-transmission device that can shift gears in multiple stages are connected in series, and its characteristic configuration is as follows: It is as follows.

A first characteristic configuration is based on information of a main shift actuator that automatically operates the main transmission, a sub-shift operation detection means that detects a switching operation of the sub-transmission, and an auxiliary shift operation detection means. and control means for automatically operating the main transmission actuator to the deceleration side so as to reduce a change in vehicle speed when the auxiliary transmission is operated to the speed increase side. be.

A second characteristic configuration is that a vehicle speed detection means and stage are provided, and the control means controls the main transmission actuator based on information from the vehicle speed detection means so that the vehicle speed does not change before and after the operation of the auxiliary transmission. The point is that it is configured to control the amount of operation.

[For production]

In the first characteristic configuration, by detecting an operation of the auxiliary transmission to the speed increasing side and automatically operating the main transmission to the decelerating side, even if the auxiliary transmission is operated to the speed increasing side, This makes it possible to reduce changes in vehicle speed.

In the second characteristic configuration, the main transmission is automatically shifted based on the detected vehicle speed so that the vehicle speed does not change before and after the operation of the sub-transmission.

〔Effect of the invention〕

In the first characteristic configuration, even if the sub-transmission device is operated to increase the speed, the change in the vehicle speed of the work vehicle can be reduced.

In the second characteristic configuration, even if the auxiliary transmission is operated to the speed increasing side, the vehicle speed can be prevented from changing before and after the operation.
The work vehicle can now run stably.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, an embodiment in which the present invention is applied to a transmission for a combine harvester as a working vehicle will be described based on the drawings.

As shown in Fig. 3, power from the engine (E) is transferred to the mission case (1) for the crawler traveling device (not shown) via a belt transmission mechanism (not shown) equipped with a tension clutch, etc. The input pulley of the continuously variable transmission (referred to as the main transmission (2) in the following explanation)
3) and the output shaft (4) of its main transmission (2).
power is transmitted to the first transmission shaft (7) via the first gear (5) and the second gear (6), and
) is transmitted to a stepped sub-transmission (8).

The power transmitted to the first transmission shaft (7) is transmitted to the auxiliary transmission (8) and also to the one-way clutch (9).
and a reaping section (not shown)
The information is also transmitted to other work equipment.

The auxiliary transmission (8) is hydraulically operated so that the output of the main transmission (2) can be switched to three stages: low speed (L), medium speed (M), and high speed (H). ing. The output is transmitted to the □ drive shafts (12L) of the pair of left and right crawler traveling devices via the first relay shaft (11), (
122), a pair of hydraulically operated left and right side clutches (13L) that can freely turn on and off drive power transmission on the left and right sides.
, (132).

However, the first relay shaft (11) is provided with a hydraulically operated brake (122) for braking the side clutch (13L), the drive shaft (12L) on the side where (132) is disengaged, and (122). 14), and a hydraulically operated reversing clutch (
15) are provided.

In other words, the drive shafts (12L) and (122) can be operated in a state where power transmission to the - side is cut off to make a slow turn, a state where one is braked and a sharp turn in a so-called pivot turn type, and a state where one side is braked and a sharp turn is made in a so-called pivot turn type. It is designed to be able to switch to a state in which the vehicle is reversed and sharply turned in a so-called spin-turn style.

Next, the configuration of each part will be explained in detail.

The auxiliary transmission (8) is transmitted to the second transmission shaft (16) via a fourth gear (15) that meshes with a third gear (14) fixed to the first transmission shaft (7). It looks like this.

The second transmission shaft (16) includes a first low speed gear (18) to which power is transmitted from the second transmission shaft (16) via a one-way clutch (F), and a hydraulically operated first speed change gear. a first medium-speed gear (20) that can be freely operated to turn on/off power transmission from the second transmission shaft (16) by a clutch (19);
and a first high speed gear (22) which can be operated to turn on/off power transmission from the second transmission shaft (16) by means of a hydraulically operated second transmission clutch (21).

the first low speed gear (18), the first medium speed gear (20)
, and the first high speed gear (22), each of which is fixed to the third transmission shaft (23), is a first low speed gear (24), a second medium speed gear (25), and a second high speed gear ( 26).

That is, when both the speed change clutches (19) and (21) are in the disengaged state, the first transmission clutch (17) is connected to the third transmission shaft (23) via the one-way clutch (17).
from the low speed gear (18) to the second low speed gear (2) meshing therewith;
4), the speed is changed to a low speed state, and the first
When the speed change clutch (19) is in the engaged state, power is transmitted from the first medium speed gear (20) to the second medium speed gear (25) meshing therewith, and the speed is changed to the medium speed state. When the two-speed clutch (21) is in the engaged state, power is transmitted from the first high-speed gear (22) to the second high-speed gear (26) meshing therewith, so that the gear is shifted to a high-speed state.

The power after shifting transmitted to the third transmission shaft (23) is:
a fifth gear (27) meshing with the second high-speed gear (26);
The pair of left and right side clutches (13L) are connected to the support shaft (28) of the fifth gear (27).

(132) A pair of left and right side gears (29L)
.

(292) are fitted onto the outside so as to be relatively rotatable.

The left and right pair of side gears (29L) and (292) are always engaged with input gears (30L) and (302) for the left and right axles (12L) and (122), respectively.

and the pair of left and right side gears (29L).

(292) are engaged with and separated from the fifth gear (27) along the axial direction, so that the left and right axles (
12L) and (122). That is, the fifth gear (27) and the pair of left and right side gears (29L),
(292), the pair of left and right side clutches (13L), (132) are configured, and the pair of left and right side clutches (13L), (132) are configured.
When one of the left and right axles (12L) and (122) is turned off, power transmission to one of the left and right axles (12L) and (122) is cut off, allowing for gentle turning.

Incidentally, a pair of left and right sixth gears (31L) and (312) are fitted onto the support shaft (27) of the fifth gear (27) so as to be relatively rotatable.
.

(312) is the left and right side fixed to the relay shaft (11).
It meshes with each of the pair of seventh gears (32L) and <322). The hydraulically operated brake (14) is provided at one end of the relay shaft (11), and the left and right pair of side gears (29L), (292) are spaced apart from the fifth gear (27). The left and right axles (12L),
(122), the sixth gear (31L), (
312), and by engaging and operating the brake (14), one of the left and right axles (12L), (122) on the side on which the pair of left and right side clutches (13L), (132) were disengaged and operated. It is now possible to brake. That is, by disengaging the left and right pair of side clutches (13L) and (132), and then engaging and operating the brake (14),
By braking one of the left and right axles (12L) and (122), it is possible to make a sharp pivot turn.

Further, the relay shaft (11) has a ninth gear that meshes with an eighth gear (33) fixed to a third transmission shaft (23) to which the power after shifting of the sub-transmission device (8) is transmitted. (34) is fitted around the relay shaft (11) so as to be relatively rotatable, and the reversing clutch (15) is configured to transmit power between the relay shaft (11) and the ninth gear (34). It is set up so that it can be turned on and off freely.

In other words, the left and right side gears (29L), (292
) to the corresponding sixth gear (31L), (31
2), the reversing clutch (
15), the power from the third power transmission shaft (23) is reversed and decelerated, and is transmitted to one of the left and right axles (12L) and (122) in a spin-turn manner. This allows it to make sharp turns.

In FIG. 3, (S0) is a vehicle speed sensor serving as vehicle speed detection means for detecting vehicle speed based on the rotational speed of the third transmission shaft (23).

Next, we will discuss the operation structure of the sub-transmission clutches (19) and (21), and the left and right side gears (29L) and (29).
2), the steering structure for sliding operation, and the operation structure for the brake (14) and the reversing clutch (15) will be explained.

As shown in FIG. 4, the hydraulic fluid sent from the pump (35) driven by the engine (E) is delivered to the first clutch (19) for the auxiliary transmission via the auxiliary transmission relief valve (36). ) and the auxiliary transmission control valve (37) for the second clutch (21), and is also supplied to the side clutch (13L), via the steering relief valve (38).
(132) A pair of left and right hydraulic cylinders (39L)
), (392) are supplied to the steering control valve (40).

The hydraulic cylinders (39L) and (392) correspond to the disengaged state of the side clutches (13L) and (132).
A bypass oil passage (41) is formed on the side surface of the cylinder. The bypass oil passage (4I) is connected to the handbrake (14) and the reverse clutch (
15), the control valve (43) for switching the operation mode, the hand brake (14), and the reverse clutch (15).
) which acts as a control valve for the variable relief valve (44
)It is connected to the.

Although not described in detail, each of the steering control valve (40), the operation mode switching control valve (43), and the variable relief valve (44) is one manually operated control valve. As the swing angle of the steering lever (46) increases from small to large, the clutch disengaged state, braking state, and
It is linked so that it can be switched to the reverse state. However, the steering lever (46) is configured to be able to swing freely in any direction (front, rear, left, right, etc.), and by swinging to the left or right, the control valve (43) for switching the operation mode and the variable relief By operating each of the valves (44) and swinging back and forth, the reaping section (not shown) can be raised and lowered.

The sub-shift control valve (37) is switched and operated by a manually operated sub-shift lever (47). In addition, a restriction is provided in the oil path which is the oil drainage side for the auxiliary transmission clutches (19), (21) by the auxiliary transmission control valve (37), and the both-side transmission clutches (19), (21) is made to overlap so that the sub-shifts can be smoothly switched.

However, the second shift clutch (21) that switches the sub-transmission device (8) to high speed (H) and the sub-shift control valve (3)
7) is connected as a pilot pressure to an operation mode switching control valve (43) that switches the operation of the brake (I4) and the reverse clutch (15), and thereby Set the device (8) to high speed (H)
, the left and right axles (12L)
, (122) to prevent sudden turns with reverse rotation.

Next, control is performed to link the main transmission (2) and the sub-transmission (8) so that the vehicle speed does not change even if the sub-transmission (8) is switched to the speed increasing side. The configuration will be explained.

As shown in FIG. 1, there is a main shift detection sensor (Sl) using a potentiometer that detects the operating state of the main shift lever (48) that operates the main transmission (2), and the auxiliary shift lever (47). ) and a sub-shift detection sensor (S2) as a sub-shift operation detection means for detecting the operating state of the sub-shift operation.

(S2) and control means for controlling the operation of the main transmission motor (49) as a main transmission actuator that operates the main transmission (2) based on the detection information of the vehicle speed sensor (S0) <100) A control device (50) using a microcomputer is provided.

In FIG. 1, (51) is a gear lever for manual operation of the main transmission (2);
51), the main speed change motor (49) is connected to the main speed change via the friction transmission mechanism (52) so that the manual speed change by the main speed change motor (49) can be performed with priority over the automatic speed change by the main speed change motor (49). It is linked to the device (2).

To explain the operation of the control device (50), when it is detected that the sub-transmission device (8) is operated to increase speed based on the detection information of the sub-shift detection sensor (S2), , as shown in FIG. 2, the vehicle speed sensor (
Based on the detection information of S0), the main transmission motor (49) is operated to automatically decelerate the main transmission (2) so that the vehicle speed is maintained at the vehicle speed before the speed increase operation. Become.

However, when the auxiliary transmission (8) is operated to the deceleration side, the main transmission (2) does not shift.

[Another example]

In the above embodiment, in order to prevent the vehicle speed from changing when the auxiliary transmission (8) is operated to increase speed, the vehicle speed is detected and the shift operation amount of the main transmission (2) is controlled. Although we have illustrated the case in which the main shift motor (49) is operated to the deceleration side during the set time, or the set amount is decelerated based on the detection information of the main shift detection sensor (SL), it is simplified. may be converted into In addition, as shown by the imaginary line in FIG. 2, the deceleration amount of the main transmission (2) is changed between the case where the main transmission (2) is not decelerated at full speed (shown by the broken line in the figure), and the vehicle speed shown by the solid line. The speed may be increased slowly in an intermediate state between the case where the speed does not change at all, or the speed change patterns may be switched.

Furthermore, in the above embodiment, the vehicle speed is kept unchanged only when the sub-transmission (8) is operated to increase speed, but as shown in FIG. The main transmission (2) may be configured to automatically increase the speed so that the vehicle speed does not change even during a deceleration operation. Also, as in the case of speed increase, the shift pattern is changed to the sub-transmission device (
A state in which the main transmission (2) automatically changes gears in conjunction with the shift operation in step 8) so that the vehicle speed does not change (the state shown by the solid line in the figure), and a state in which it gradually decelerates (the state shown by the imaginary line in the figure) ), and the main transmission (2) may be switched between a full (non-shift state (state indicated by a broken line in the figure)).

Further, in the above embodiment, the case where the present invention is applied to the transmission of a combine harvester is illustrated, but the present invention can be applied to the transmission of various types of work vehicles, and the specific configuration of each part can be changed in various ways.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the transmission device for a working vehicle according to the present invention,
Fig. 1 is a block diagram of the control configuration, Fig. 2 is an explanatory diagram of the speed change characteristics during speed increase operation, Fig. 3 is a hydraulic circuit diagram, Fig. 4 is an explanatory diagram of the power transmission system in the transmission case,
FIG. 5 is an explanatory diagram of the speed change characteristics during deceleration operation. (2) Main transmission, (8) Sub-transmission, (49) Main transmission actuator, (S,)... Vehicle speed detection means (S2)...
...Sub-shift operation detection means, (100)...
control means.

Claims (1)

[Scope of Claims] 1. A transmission for a work vehicle in which a main transmission (2) that can shift continuously and a sub-transmission (8) that can shift in multiple stages are connected in series. There, the main transmission (2
) Main gear shift actuator (49) that automatically operates the
and a sub-shift operation detection means (S_2) that detects a switching operation of the sub-transmission device (8), and a sub-shift operation detection means (S_2) that detects a switching operation of the sub-transmission device (8).
control means (100) for automatically operating the main shift actuator (49) to the deceleration side so as to reduce a change in vehicle speed when the vehicle is operated to the speed increase side. transmission. 2. The transmission device for a work vehicle according to claim 1, further comprising a vehicle speed detection means (S_0), and the control means (100).
is configured to control the operating amount of the main transmission actuator (49) based on the information of the vehicle speed detection means (S_0) so that the vehicle speed does not change before and after the operation of the auxiliary transmission (8). transmission of a working vehicle.