JP3599489B2 - Work equipment transmission - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power transmitting device for a working machine having a transmission with a continuously variable belt mechanism.
[0002]
[Prior art]
As the above-mentioned transmission, a combine transmission disclosed in Japanese Patent Application Laid-Open No. 7-241132 is known, in which engine power is firstly shifted by a belt continuously variable transmission mechanism and then input to the transmission. The transmission is transmitted to the traveling device after deceleration via a forward / reverse switching mechanism operated by a hydraulic clutch. The adoption of the belt continuously variable transmission mechanism has an advantage that the selection range of the reduction ratio as the main transmission mechanism can be widened, while being relatively inexpensive.
[0003]
[Problems to be solved by the invention]
The belt continuously variable transmission mechanism is capable of variably adjusting a gear ratio by changing a belt winding radius using a split pulley, and adjusting a belt tension by using only one of a pair of pulleys as a split pulley. There is a structure in which both of them are split pulleys, and a structure in which the speed is changed by reciprocally enlarging or reducing the belt winding radius. In either structure, the actuator is biased toward the high-speed side or the low-speed side (usually biased toward the low-speed side), so that either the high-speed operation or the low-speed operation opposes the biasing force. It becomes a heavy operation to press the belt. Therefore, as shown in the above-mentioned publication, the shift lever can be operated lightly by using the assist motor.
[0004]
However, when a transmission is configured by combining a transmission and a belt continuously variable transmission mechanism, for example, a transmission, a belt continuously variable transmission mechanism, a shift lever, an assist mechanism, and the like are interlocked while individually supported. When a structure is adopted, it is easy to perform design and maintenance as a single function, but it is difficult to achieve dimensional accuracy of the entire transmission, and it is difficult to perform inspection and maintenance, and the structure is easily complicated.
SUMMARY OF THE INVENTION It is an object of the present invention to configure a transmission device having a belt continuously variable transmission mechanism so that the configuration is simple and compact, and that inspection and maintenance can be easily performed.
[0005]
[Means for Solving the Problems]
〔Constitution〕
According to a first aspect of the present invention, there is provided a speed change lever for enlarging / reducing a belt winding radius of a split pulley in a belt case surrounding a belt continuously variable transmission mechanism having a split pulley whose belt winding radius can be changed and adjusted; And an assist mechanism for assisting the operation force of the belt, the belt transmission unit is configured, and the assist mechanism rotates about the axis of the input shaft to which the split pulley is mounted, and rotates the beltless unit. A gear reduction mechanism comprising a fan-shaped gear for shifting the speed of the stepped transmission mechanism, and a pinion gear engaged with an arc gear portion of the sector-shaped gear and rotatably mounted on an assist motor so as to be able to rotate forward and reverse. to attach the case to the outer surface of said pinion gear (55a) and the opposing portion of the belt case in the axial direction as viewed in the input shaft (5) (1a), said assist motor The supporting case was charged, attached by fixing to via a stay, the belt traveling system of the gear speed change mechanism a transmission unit is characterized in that are annexed detachably on the transmission case to be furnished.
[0006]
According to a second aspect of the present invention, the assist mechanism is configured so that the assist motor drives the shift lever in the operating direction in response to detection of the start of operation of the shift lever, and the power of the assist motor can be reversibly driven. The transmission is transmitted to the transmission lever via a simple gear reduction mechanism.
[0007]
[Action]
According to the configuration of the first aspect, since the shift lever and the assist mechanism are integrally provided in the belt case, it is easier to maintain good mounting dimensional accuracy than in a case where they are separately supported. It is possible to reduce the cost by reducing the dimensional accuracy of the device, or to reduce the operating force by reducing the length and weight of the movable part. Then, since the belt continuously variable transmission mechanism in which the operation system is integrated is detachably attached to the transmission case, the modularized parts are assembled together. Therefore, it is easy to perform inspection and maintenance using the belt continuously variable transmission mechanism and the transmission alone, separately from the transmission case.
[0008]
According to the configuration of the second aspect, the power of the assist motor that assists the shift operation force is transmitted to the shift lever through the reversible driveable gear reduction mechanism. The assist motor can be rotated by the operation on the side, and the shift operation can be performed. For example, when operating a combine placed in a field, even if the assist mechanism breaks down, the operation force is heavy but the gearshift operation is possible, so you can run back to the warehouse for repair or work a little more as it is It becomes possible to do.
[0009]
〔effect〕
In the transmission according to claim 1 or 2, the belt continuously variable transmission mechanism and its operation system can be integrally attached to and detached from the transmission, so that inspection, maintenance, and testing can be easily performed, and the cost can be reduced. I was able to.
[0010]
According to the power transmission device of the second aspect, there is an advantage that the speed change operation can be performed even if the assist mechanism breaks down, the work can be continued, or the user can return to a repair place.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a combine transmission, in which reference numeral 1 denotes a belt continuously variable transmission mechanism, 2 denotes a mission, and 3 denotes a crawler traveling device. As shown in FIG. 6, the belt continuously variable transmission mechanism 1 includes a drive shaft 5 having an input pulley 4 for receiving engine power, and a driven shaft 6 serving as an output shaft to a transmission. Split pulley structure provided with the driven split pulley 7 and the driven split pulley 8 formed on the driven shaft 6. The speed change operation is an operation of expanding / reducing the belt winding radius of the driving side split pulley 7 by operating the transmission lever 9, and the expansion / contraction change of the belt winding radius of the driven side split pulley 8 follows the expansion / contraction change. . Further, an assist mechanism B using an electric motor for assisting the operation force of the shift lever 9 is provided.
[0012]
The driven split pulley 8 has a movable pulley piece 8B externally rotatably fitted to a boss 8a of a fixed pulley piece 8A on which the driven shaft 6 is integrally formed, and a spline externally fitted to the boss 8a. 28 and a cam portion 29 extending over the movable pulley piece 8B. The cam portion 29 is formed in a cylindrical shape so that the movable pulley piece 8B can slide in the axial direction with respect to the fixed pulley piece 8A, and is linked to rotate integrally. For example, a pair of dog rings each provided with a plurality of claws protruding in the axial direction are arranged to face each other. A winding spring 30 is provided for urging the movable pulley piece 8B against the fixed pulley piece 8A in the axial direction in the direction in which the belt winding radius increases, and the winding spring 30 surrounds the cam portion 29. The cam 29 is set so as to be a spring guide.
[0013]
As shown in FIG. 6, the driving side split pulley 7 attached to the input shaft 5 having the input pulley 4 has a fixed pulley piece 7A integral with the input shaft 5 and a fixed rotation pulley piece 7A that cannot be relatively rotated. And a movable pulley piece 7B slidable in the axial direction. A ring member 34 is externally fitted to the movable pulley piece 7B of the drive side split pulley 7 via a bearing, and a pair of pins 34a fixed to the ring member 34 is inserted into the concave portion 33 of the continuously variable transmission mechanism 1 on the belt case side. The ring member 34 is prevented from rotating. A cylindrical cam member 36 is externally fitted to the input shaft 5 via a bearing. As shown in FIG. 7, a concave portion 35 composed of a linear bottom portion 35a and a pair of right and left symmetric inclined surfaces 35b is formed. The roller 34 b of the pin 34 a of the ring member 34 is inserted into a pair of concave portions of the cam member 36.
[0014]
In the state shown in FIG. 6, the movable pulley piece 7B of the driving side split pulley 7 is farthest to the left from the fixed pulley piece 7A on the paper surface, and the movable pulley piece 8B of the driven side split pulley 8 is closest to the fixed pulley piece 8A. This is the state of the high speed position. Then, when the cam member 36 is moved right or left from this state, the ring member 34 and the movable pulley piece 7B of the driving side split pulley 7 are pushed to the fixed pulley piece 7A side via the inclined surface 35b. As a result, the winding radius of the transmission belt 31 at the driving split pulley 7 increases, and the movable pulley piece 8B of the driven split pulley 8 moves away from the fixed pulley piece 8A to the right in the drawing. As a result, the belt continuously variable transmission mechanism 1 is shifted to a higher speed.
[0015]
Next, a shift operation of the belt continuously variable transmission mechanism 1 will be described.
As shown in FIGS. 2 and 4 to 6, a boss member 38 is fixed to the end of the cam member 36 outside the belt continuously variable transmission mechanism 1, and the speed change lever 9 is arranged around the horizontal axis P1 of the boss member 38. The fan gear 40 is supported so as to be able to swing left and right, and the fan gear 40 is fixed to the boss member 38. An electric motor 55 for assisting the rotation of the fan gear 40 is provided. The pin 38b of the arm 38a of the boss member 38 is inserted into the opening 40a of the sector gear 40, and the pair of rubber-like pressure-sensitive sensors 56 sandwich the pin 38b of the arm 38a. Fixed to.
[0016]
The state shown in FIG. 5 is a state in which the shift lever 9 is operated to the neutral stop position N, and corresponds to the states shown in FIGS. 6 and 7. In this state, when the shift lever 9 is operated to the forward side F or the reverse side R to rotate the cam member 36, the pin 38b of the arm 38a is pressed by the pressure sensor 56 by this operation, and , The electric motor 55 is operated so that the boss member 38 and the sector gear 40 rotate in the operation direction of the shift lever 9, and the belt continuously variable transmission mechanism 1 is shifted to the high speed side by a light operation by the assist force. Is done. Then, when the operation of the shift lever 9 is stopped at a desired operation position, the contact between the pin 38b and the pressure-sensitive sensor 56 is released, the electric motor 55 is also stopped, and the shift lever 9 and the belt continuously variable transmission mechanism 1 are stopped. It is held in the operating position.
[0017]
The pinion gear 55a of the electric motor 55 and the arc gear part 40d of the sector gear 40 constitute a reversible ( reversible drive) gear reduction mechanism 84 capable of rotating the electric motor 55 with the shift lever 9, and this gear The assist mechanism B is constituted by the speed reduction mechanism 84, the electric motor 55, the pair of pressure sensors 56, 56, and the like. In other words, the electric motor (assist motor) 55 drives the shift lever 9 in the operating direction in response to the detection that the shift lever 9 has started operating. In addition, since the urging force of the winding spring 30 of the driven split pulley 8 generates a force that pushes the speed change lever 9 lightly to the low speed side, the control for flowing a weak current to the electric motor 55 so that the force can be canceled and the lever can be held is also performed. Is going.
[0018]
Further, a volume (potentiometer) 80 for detecting the swinging position of the sector gear 40 with respect to the belt case 1a is provided so that the operating position of the shift lever 9 can be electrically detected. That is, as shown in FIG. 5, the volume 80 is bolted to the belt case 1a side at a position between the sector gear 40 and the belt continuously variable transmission mechanism 1, and the operation shaft 80a is formed on the sector gear 40. The detection arm 81 is attached to the end of the fan hole 40b. The pin 81a fixed to the tip of the detection arm 81 is fitted in the long hole 40c formed in the sector gear 40, and the operation position of the sector gear 40, that is, the shift lever 9 is changed by the above configuration. The volume 80 can be detected.
[0019]
Next, a description will be given of a linkage structure between the belt continuously variable transmission mechanism 1 and the forward and reverse clutches Cf, Cr.
As shown in FIG. 3, the operating oil of the pump 16 is supplied to the forward clutch Cf and the reverse clutch Cb via the flow priority valve 39 and the first control valve 18, and the first control valve 18 is connected to the forward clutch Cf A neutral stop position in which the hydraulic oil is removed from the reverse clutch Cb and both are turned off, a forward position in which the hydraulic oil is supplied to the forward clutch Cf to be engaged, and a hydraulic oil is supplied to the reverse clutch Cr. There are three reverse positions for entering and operating the vehicle.
[0020]
As shown in FIGS. 2 and 4, the boss member 38 supporting the shift lever 9 is supported by the ring member 36, that is, the belt case 1 a, and a reversible drivable speed reduction mechanism (not shown) and the electric motor 55 are provided. Is fixed to the belt case 1a via a stay 42 with bolts. That is, a modularized belt transmission unit U in which the shift lever 9, the assist mechanism B, and the belt continuously variable transmission mechanism 1 are integrated via the belt case 1a is configured. It is bolted to the case 2a. Therefore, the belt continuously variable transmission mechanism 1 can be easily removed from the transmission case 2a to perform inspection, maintenance, a durability test, and the like.
[0021]
As shown in FIG. 1, the transmission 2 includes an input shaft 10 that is linked to the driven shaft 6 of the belt continuously variable transmission mechanism 1, and includes a PTO pulley 11, a PTO hydraulic clutch Cp, a forward / reverse switching mechanism A, and a three-stage high / low gear. The vehicle includes a sub-gear transmission mechanism 12, left and right side clutches and brakes 13, 13, left and right axles 14, 14, and the like. The forward / reverse switching mechanism A is provided with a forward hydraulic clutch Cf and a reverse hydraulic clutch Cb, and selects one of them to perform an on operation.
[0022]
The forward / reverse switching mechanism A includes the above-described hydraulic clutches Cf and Cb for forward and reverse travel, input and output gears 25a and 25b for forward travel, and input and output gears 26a and 26b for reverse travel. When the forward hydraulic clutch Cf is turned on, a forward state in which the power of the input shaft 10 is transmitted to the input gear 27 of the sub-gear transmission mechanism 12 via the forward gears 25a and 25b appears, and the reverse hydraulic clutch When Cb is turned ON, a reverse state in which the power of the input shaft 10 is transmitted to the input gear 27 of the sub-gear transmission mechanism 12 via the forward input gear 25a and the reverse gears 26a and 26b appears. .
[0023]
Since the belt continuously variable transmission mechanism 1 cannot switch between forward and reverse rotation and manifest a transmission neutral state as in the case of HST, it operates as a hydraulic clutch type forward / reverse switching mechanism A and neutralizes any of the hydraulic pressures. The clutch Cf, Cb is also disengaged to bring out a neutral state. The PTO clutch Cp is also linked so as to be disengaged in the running neutral state, and is controlled so that a state in which the reaping unit is driven when the body is stopped is not generated. However, since the mowing unit is stopped and the running unit is required to be in a transmission state during traveling or the like, a belt tension type mowing clutch 15 is provided outside the transmission 2.
[0024]
FIG. 3 shows a hydraulic circuit diagram, wherein 16 is a hydraulic pump, 17 is an oil cooler, 18 is a first control valve for switching between forward and reverse, 19 is a second control valve for steering, and 20 is a negative brake. Accumulator. The hydraulic oil of each hydraulic device is also used as the transmission oil, and as shown in FIG. 2, the discharge oil of the hydraulic pump 16 is supplied to a valve unit 21 provided on the side surface of the transmission case 2a. It is discharged into the case 2a. The oil discharged from the oil outlet 22 provided at the lower part of the transmission case 2a is formed into a closed circulation path L that is cooled by the oil cooler 17 and then returns to the hydraulic pump 16.
[0025]
The accumulator 20 is linked so as not to operate when the first control valve 18 is at the neutral position, but to operate when the first control valve 18 is at a position other than the neutral position. 20b functions to move in and out. The piston rod 20b of the accumulator 20 formed in the valve unit 21 and the arm 13a of the side clutch / brake 13 are linked by an operation cable 61. When the accumulator 20 is not operated, both the side clutch / brake 13, 13 are braked. When the vehicle is running, the brake is released. When the vehicle stops, a negative brake that automatically applies a brake to the left and right traveling devices 3 and 3 is configured. It is.
[0026]
As shown in FIGS. 2 and 4, the belt case 1a and the transmission case 2a of the belt continuously variable transmission mechanism 1 are integrally connected so as to come into contact with each other with a relatively large area at the driven shaft 6 (input shaft 10). The heat generated by the belt continuously variable transmission mechanism 1 is relatively easily conducted to the transmission case 2a. Then, the heat transmitted to the transmission case 2a is transmitted to the hydraulic oil, is efficiently cooled mainly by the oil cooler 17 in the above-described circulation path L, and is also made of a metal external from the oil outlet 22 to the valve unit 21. Pipes a, b, and c are provided, and a natural heat radiation effect of these external pipes a, b, and c can be expected. Therefore, the heat generated by the belt continuously variable transmission mechanism 1 can be efficiently cooled by using the hydraulic oil circulation path L.
[0027]
The valve unit 21 includes first and second control valves 18 and 19, and an accumulator 20, and is directly connected to the outer surface of the transmission case 2a. The transmission 2 and the valve unit 21 that can be used to form an oil passage and use the same hydraulic oil are made more compact. An oil strainer (not shown) is provided inside the oil outlet 22.
[0028]
The electric motor 55 for assist is also used as an operation motor for vehicle speed control in vehicle speed control. In brief, a vehicle speed control that automatically adjusts the vehicle speed so that the engine load during work traveling is within an appropriate range by enabling the engine speed to be maintained in the target speed range is enabled. The electric motor 55 for assist is also used as a drive source for adjusting the vehicle speed based on the above.
[Brief description of the drawings]
FIG. 1 is a diagram showing a transmission system of a combine. FIG. 2 is a side view of a transmission including a hydraulic oil cooling circuit. FIG. 3 is a hydraulic circuit diagram. FIG. 4 is a front view of the entire transmission. FIG. FIG. 6 is a sectional view showing the structure of a continuously variable belt transmission mechanism. FIG. 7 is a plan view showing the vicinity of a cam member of the continuously variable belt transmission mechanism.
Reference Signs List 1 belt continuously variable transmission mechanism 1a belt case 2a transmission case 70 split pulley 9 transmission lever 55 assist motor 84 gear reduction mechanism B assist mechanism U belt transmission unit

Claims (2)

The belt winding radius of the split pulley (7) is increased or decreased by a belt case (1a) surrounding a belt continuously variable transmission mechanism (1) including a split pulley (7) whose belt winding radius can be changed and adjusted. And a power transmission lever (9), and an assist mechanism (B) for assisting the operating force of the transmission lever (9). A sector gear (40) that rotates about the axis of the input shaft (5) to which the split pulley (7) is attached and operates the belt continuously variable transmission mechanism (1) to shift; A gear reduction mechanism (84) comprising a pinion gear (55a) attached to the assist motor (55) so as to be capable of normal and reverse rotation, the gear reduction mechanism (84) being engaged with an arc gear part (40d) of the gear (40); Into the belt case (1a). In Keru, the outer surface of said pinion gear (55a) and the opposing portion of the belt case in the axial direction as viewed in the input shaft (5) (1a), support case was furnished the assist motor (55) to (41), stay (42) mounted by fixing to via, the belt transmission units (U) of the traveling system of the gear shift mechanism (12) is working machine are annexed detachably on the transmission case (2a) to be decorated Gearing. The assist mechanism (B) is configured such that the assist motor (55) drives the shift lever (9) in the operating direction in response to detection of the start of the shift lever (9) operation. The transmission of a working machine according to claim 1, wherein the power of the assist motor (55) is transmitted to the shift lever (9) via a reversible gear reduction mechanism (84).

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