JP3096590B2 - Work vehicle transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for use in a working vehicle such as a combine, for example, and more particularly, to a belt-type continuously variable transmission for shifting engine power, and power from the belt-type continuously variable transmission. And a neutral detection means for detecting that the belt-type continuously variable transmission is set to a neutral position for shifting, and an output detection for detecting an output state of the gear-type transmission. And a transmission device for a working vehicle provided with the means.

[0002]

2. Description of the Related Art In this type of belt type continuously variable transmission, slippage may occur due to its structure.
In particular, the tendency increases as the load increases.

[0003]

If the operation of the work vehicle is continued in a state where such slippage has occurred, it is not preferable to cause burning of the belt or the like. Therefore, it was necessary to somehow detect the belt slip early and deal with it.
Conventionally, such measures have not been taken. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a transmission device for a work vehicle that can detect belt slippage at an early stage and take effective measures against the slippage.

[0004]

According to a first aspect of the present invention, in a state where the neutral detecting means detects that the shift position is other than neutral, the output detecting means temporarily detects an output state. The control means for stopping the engine when it is detected that the state has been switched to the state in which no output is performed is provided. The operation and effect are as follows.

[0005]

In other words, if the neutral detecting means detects that it is in a shift position other than the neutral position, the output from the gear type transmission located on the transmission lower side of the belt type continuously variable transmission is always its output. Must be detected, but since it is detected once and then no longer detected, the gear type transmission is operating normally and there is slippage in the belt type continuously variable transmission. It is considered that In particular, it is considered that the load has become excessively large since the belt has once risen, and slippage has occurred in the belt continuously variable transmission. Therefore, the engine is stopped and the belt continuously variable transmission is stopped.

[0006]

As a result, the seizure of the belt in the belt continuously variable transmission can be prevented. And
There is no need to employ a belt continuously variable transmission having a large capacity that can withstand a high load.

[Other objects, configurations, functions and effects] (1) The object of the invention in claim 2 is the same as the object of the invention in claim 1, and the configuration adopted for this purpose is as follows.
A gear-type transmission for further shifting the power from the belt-type continuously variable transmission; a neutral detecting means for detecting that the belt-type continuously variable transmission is set to a neutral position for shifting; and the gear-type transmission. A transmission system provided with output detection means for detecting an output state of the belt-type continuously variable transmission, and a belt-type continuously variable transmission based on an operation on the speed-changeable transmission. A shift movable body for setting a shift state of the device; and a drive device for moving the shift movable body and the shift operation tool, to form an operation system, and the drive device is configured based on an operation on the shift operation tool. Control means for controlling the gear position, wherein high-speed detection means for detecting that the gear-type transmission is at a high-speed position is provided, and the control means causes the neutral detection means to change the shift position other than the neutral position. And if the output detection means does not detect the output state of the gear-type transmission while the high-speed detection means detects that it is at the high-speed position, the drive device is operated to operate the continuously variable transmission. Is returned to neutral, and its operation and effect are as follows. In other words, although the operation state of the belt-type continuously variable transmission and the gear-type transmission is such that the drive output can be obtained, the output of the gear-type transmission shows a state of substantially zero. Judging that the stepped transmission is slipping, this time return the belt type continuously variable transmission to the neutral position,
The operation of the belt-type continuously variable transmission is stopped. Thereby, slippage of the belt in the belt type continuously variable transmission can be prevented. And since there is no need to stop the engine, there is an advantage that the power supply to other devices other than the traveling device can be maintained.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a combine transmission as an example of a work vehicle. That is, the power from the engine E is transmitted to the input pulley 2 of the belt-type continuously variable transmission 1 via the belt transmission mechanism B having a tension clutch, and the output power from the belt-type continuously variable transmission 1 is transmitted to the transmission. The input is made in case 3.

As shown in FIGS. 1 and 2, in the transmission case 3, a forward drive shaft 4 and a reverse drive shaft 5 are provided.
Are arranged side by side in parallel, and the transmission case 3
1 is deviated from the left and right center to one lateral side to the left in FIG. A forward hydraulic clutch 6 and a forward input gear 7 for transmitting forward power to a lower transmission side in the transmission case 3 are attached to the forward transmission shaft 4.
A reverse hydraulic clutch 8 and a reverse input gear 9 for transmitting reverse power to the transmission lower side in the transmission case 3 include:
The transmission gear 5 is attached to the reverse transmission shaft 5 while meshing with the forward input gear 7.

In the upper part of the transmission case 3, FIG.
As shown in FIG. 2, a hydraulic plate 10 extending between the forward and reverse drive shafts 4 and 5 is connected, and hydraulic oil from a forward / reverse switching valve (not shown) is supplied to the forward and reverse drive shafts 4 and 5. 5, the hydraulic fluid is supplied to the forward hydraulic clutch 6 and the reverse hydraulic clutch 8.
Further, as shown in FIG. 1, a gear pair 11 for a pre-cutting processing unit (not shown) at the front of the fuselage of the combine, and this gear pair 1
Transmission shaft 12, output shaft 13 as a support shaft supporting
And an input shaft 15 for inputting power from the belt-type continuously variable transmission 1,
In the transmission case 3, it is arranged above the forward and reverse transmission shafts 4, 5, and is biased to one lateral side of the transmission case 3 on the same side as the forward and reverse transmission shafts 4, 5. Here, the first gear 11a of the gear pair 11 meshes with the drive gear 16 and the forward input gear 7 provided on the input shaft 15, and the second gear 11b of the gear pair 11 The input gear 17 of the hydraulic clutch 14 for the mowing pre-processing unit is engaged. And these gear pairs 1
1, the drive gear 16 and the input gear 17 constitute a mowing pre-processing unit and a transmission mechanism 18 to a forward / reverse transmission shaft. The forward input gear 7, the reverse input gear 9, the input gear 17
Are supported by the shafts 4, 5, and 12 so that when the hydraulic clutches 6, 8, and 14 are in the off state, they are idle.

Further, as shown in FIG. 1, the outputs of the forward hydraulic clutch 6 and the reverse hydraulic clutch 8 are output from a sub-transmission 19 and a side clutch 2 as a gear type transmission.
0,20 via the axle 2 of the crawler traveling device 21,21
2 and 22.

Next, the belt type continuously variable transmission 1 will be described. As shown in FIG. 2, the belt-type continuously variable transmission 1
Is constructed such that a driving pulley PK, a passive pulley PJ, and a transmission belt 23 extending over both pulleys are housed in a transmission case Ca having a half-split structure. Both the driven and passive pulleys PK and PJ are configured in a split pulley structure in which the belt winding radius can be variably adjusted, and the belt winding radius of each pulley is linked so as to be reciprocally adjusted.

An input pulley 26 to which power is transmitted is fixed to an outer portion of the half case 25A with respect to the drive shaft 24 on the power transmission upper side.
A drive pulley PK is mounted on the inside of A. The drive pulley PK is composed of a fixed pulley piece 27A fixedly mounted on the drive shaft 24 and a movable pulley piece 27B, and the pulley portion 27B is opposed to the fixed pulley piece 27A.
In addition, it is fitted outside so as to be integrally rotatable and movable in the axial direction by the structure of the ball and the groove.

A ring member 28 is rotatably fitted to the boss portion of the movable pulley piece 27B via a bearing 29. A receiving member 28b is attached to a pair of pins 28a fixed to the ring member 28. The ring member 28 is prevented from rotating into the concave portion 25a of the half case 25B. The cylindrical cam member 30 includes a pair of bearings 31.
The cam member 30 has a pair of concave portions formed by a pair of inclined surfaces 30a symmetrical to the left and right.
8 c has entered the pair of concave portions of the cam member 30.

In the passive shaft 32 on the lower side of the transmission, a fixed pulley piece 33 is disposed inside the other half case 25B, and a movable pulley piece 34 is integrated with the passive shaft 32 in opposition to the fixed pulley piece 33. It is externally fitted so as to be rotatable and movable in the axial direction. The movable pulley piece 34 of the passive shaft 32 is urged toward the fixed pulley piece 33 by a spring 35, and the cam pushes the movable pulley piece 34 toward the fixed pulley piece 33 in proportion to an increase in the load on the passive shaft 32 side. A mechanism 36 is provided.

In the state shown in FIG. 2, the movable pulley piece 27B of the drive shaft 24 is farthest to the left from the fixed pulley piece 27A on the paper surface, and the movable pulley piece 34 of the passive shaft 32 is
Is the state of the lowest speed position closest to. Then, when the cam member 30 is rotated right and left from this state, the movable pulley piece 27B of the ring member 28 and the drive shaft 24 is pushed toward the fixed pulley piece 27A side via the inclined surface 30a, and approaches. As the winding radius of the transmission belt 23 around the driving pulley PK increases, the movable pulley piece 34 of the passive shaft 32 moves away from the fixed pulley piece 33 to the right in the drawing. The device 1 is shifted to a higher speed.

Next, the speed change operation structure of the belt type continuously variable transmission 1 will be described. As shown in FIGS. 2 and 3,
A boss member 37 is fixed to the boss portion of the cam member 30 outside the half case 25B, and the boss member 37 supports a shift lever 38 as a shift operation tool.
7, a sector-shaped gear 39 as a movable body for shifting is fixed,
A geared motor 40 is provided as a driving device for driving the sector gear 39 to rotate. And the boss member 3
7, the pin 37b of the arm 37a is inserted into the opening 39a of the sector gear 39, and a pair of rubber-shaped pressure-sensitive sensors 41 as the operation direction detecting sensor of the shift lever 38 sandwich the pin 37b of the arm 37a. Fan gear 39
It is fixed to.

The state shown in FIG. 3 is a state in which the shift lever 38 is operated to the neutral stop position. From this state, when the shift lever 38 is operated in the front-back direction of the paper to rotate the cam member 30, this state is shown. By operation, the pin 37b of the arm 37a is pressed by the pressure-sensitive sensor 41,
The transmission lever 38
The motor 40 operates so that the boss member 37 and the sector gear 39 rotate in the operation direction of the belt type continuously variable transmission 1.
Is shifted to the high speed side. When the operation of the transmission lever 38 is stopped at a desired operation position, the motor 40 is also stopped, and the transmission lever 38 and the belt-type continuously variable transmission 1 are held at this operation position by the motor 40.

In one having the above configuration,
A description will be given of measures to be taken when the belt-type continuously variable transmission 1 slips. As shown in FIG. 3 and FIG.
9, a projection 39A is provided at the base end of the
A limit switch 42 for detecting contact of the belt 9 is provided, and constitutes a neutral detecting means for detecting a neutral position of the belt-type continuously variable transmission 1. On the other hand, a rotation sensor 43 for detecting the rotation state of the output shaft 19 is provided on the output shaft 19A of the auxiliary transmission 19 in the transmission case 3, and constitutes an output detection means for detecting the output state of the auxiliary transmission 19. In a state where the limit switch 42 does not detect the protrusion 39A, that is, in a running state where the rotation state is not the neutral state as shown in FIG. 3, the rotation sensor 43 once detects the rotation of the output shaft 19A and then stops the rotation of the output shaft 19A. When the detection is no longer performed or when the rotational speed is as close to zero as possible, the engine E is stopped because the belt-type continuously variable transmission 1 is considered to have slipped. Such a slipping state is more likely to occur when the vehicle is set to run at a high speed and with a high load. Therefore, when such a slip occurs, it is considered that the vehicle can escape in a reverse traveling state at a low speed. However, when the rotation sensor 43 does not detect the rotation of the output shaft 19A from the beginning in a running state other than the neutral state, it is considered that the auxiliary transmission 19 is operated to the neutral operation position, and the engine E Do not stop. [Other Embodiments] (1) As a countermeasure for the case where the belt-type continuously variable transmission 1 slips, a mode in which the shift lever 38 and the sector gear 39 are returned to the neutral position without stopping the engine E is adopted. May be taken. (2) The following configuration may be adopted as a measure to cope with the slippage of the belt-type continuously variable transmission 1. That is,
As shown in FIGS. 5A and 5B, a limit switch 42 is provided so as to detect the neutral position of the shift lever 38, and a shift lever 44 for the sub-transmission 19 is provided. A limit switch 45 is provided as high-speed detection means for detecting that the operation has been performed,
When the speed sensor 38 for the belt-type continuously variable transmission 1 is in a running position other than the neutral position and the speed lever 44 for the subtransmission 19 is in the high-speed position, and the rotation sensor 43 detects a substantially zero output state, , The engine E is stopped, or the belt-type continuously variable transmission 1 is returned to the neutral position. (3) In addition to the limit switch 42, a non-contact type sensor such as light may be used as the neutral detecting means. (4) As the output detection means 43, a rotation sensor such as an encoder and a potentiometer can be used. (5) Although a pressure-sensitive sensor is used as the operation direction sensing sensor 41, a non-contact sensor such as light can be used. (6) As the driving device 40, a cylinder or the like can be used other than the motor. (7) As another countermeasure when the belt continuously variable transmission 1 slips, the speed change lever 38 is decelerated by a set amount, and the engine E is stopped if the slip has not been eliminated by the set number of times of deceleration.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a traveling transmission system of a combine.

FIG. 2 is a sectional view showing a belt-type continuously variable transmission.

FIG. 3 is a side view showing an operation structure for the belt-type continuously variable transmission.

FIG. 4 is a control configuration diagram.

FIG. 5 is a plan view showing an operation tool for a belt-type continuously variable transmission and an operation tool for a gear type transmission.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 belt-type continuously variable transmission 19 gear-type transmission 38 speed-change operation tool 39 speed-change movable body 40 drive device 42 neutral detection means 43 output detection means 45 high-speed detection means 46 control means E engine

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-148922 (JP, A) JP-A-4-203645 (JP, A) JP-A-63-162355 (JP, A) 164040 (JP, U) Japanese Utility Model 2-3929 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A01D 69/00 302 A01B 71/02 B60K 17/08 F16H 61/12

Claims (2)

(57) [Claims] 1. A belt-type continuously variable transmission (1) for shifting the power of an engine (E), and the belt-type continuously variable transmission (1).
A gear-type transmission (19) for further shifting the power from the vehicle, a neutral detection means (42) for detecting that the belt-type continuously variable transmission (1) is set to a neutral position for shifting, and An output detecting means (43) for detecting an output state of a gear type transmission (19), wherein the neutral detecting means (42) is in a shift position other than neutral. A control means (46) for stopping the engine (E) when the output detection means (43) detects that the state has been changed to a state in which no output is performed after the output detection means (43) once detects the output state is provided. Transmission of a working vehicle. 2. A gear type transmission (19) for further shifting the power from the belt type continuously variable transmission (1), wherein the belt type continuously variable transmission (1) is set to a neutral position for shifting. And a belt-type continuously variable transmission, comprising: a neutral detection means (42) for detecting the above-mentioned situation; and an output detection means (43) for detecting an output state of the gear type transmission (19). A speed change operation tool (38) for (1), a speed change movable body (39) for switching a speed change state of the belt type continuously variable transmission (1) based on an operation on the speed change operation tool (38), Moving body for shifting (3
9) and a driving device (4) for moving the shift operation tool (38).
0) and a control means (46) for controlling the drive device (40) based on an operation on the speed change operation tool (38). A high-speed detecting means (45) for detecting that the gear type transmission (19) is at a high-speed position; and the control means (46) controls the neutral detecting means (4).
2) the output detecting means (43) detects the output state of the gear type transmission (19) in a state in which the gear shift position other than the neutral position is detected and the high-speed detecting means (45) detects the high-speed position. If not, a transmission for a working vehicle configured to operate the drive unit (40) to return the belt-type continuously variable transmission (1) to neutral.