JP3484614B2 - Transmission of agricultural work machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for an agricultural work machine such as a management machine equipped with a rotary work machine for performing tilling work. 2. Description of the Related Art Conventionally, there has been a technology of performing a shift without interrupting power transmission using a ball clutch, that is, a non-clutch, and a shifter shaft having a projection for engaging the ball clutch is provided by a shift lever. By pulling the operation wire extending from the compression spring, the operation wire is moved to the high-speed position against the compression spring, and by loosening the operation wire, the operation wire is moved to the low-speed position by the restoring force of the compression spring. [0003] However, in the above-described configuration, a compression spring is used, and the shifter shaft is moved to one side against the urging force of the compression spring. This necessitates a problem that the operation of the shift lever becomes heavy and the operability is poor. [0004] A main object of the present invention is to provide an agricultural work machine capable of moving a shifter shaft with a light operating force, having the advantage of being able to shift without a clutch, and further improving the shift operability. It is in providing a transmission. In order to achieve the above object, a plurality of transmission gears are removably supported via a ball clutch in a transmission case, and the transmission shaft has a hollow hole. A shifter shaft movably inserted into the hollow hole and having a projection for engaging the ball clutch, and a fixed cam body disposed around the axis of the shifter shaft and having a multi-stage cam surface at a circumferential position. And an operation body that abuts against the multi-stage cam surface and moves the shifter shaft, wherein both ends of the shifter shaft project outside the transmission case, The fixed cam bodies are respectively arranged around the section so that the multi-stage cam surface is on the opposite side to the transmission case, and the operating bodies are respectively supported at the both ends, and the multi-stage cam surface of each fixed cam body is provided. And a roller for moving the shifter shaft to one side and the other side by contacting the shifter shaft. According to the first aspect of the present invention, the shifter shaft can be moved to the forward and backward sides by the fixed cam bodies and rollers provided at both ends. In addition, the conventional compression spring can be dispensed with, and the shift to the high speed stage and the shift to the low speed stage can both be performed by a light operating force. 1 and 2, 1 is an engine, 2 is an engine stand, 3 is a transmission case, 4 is a transmission case for transmitting the power of the engine 1 to the transmission case 3, Reference numeral 5 denotes an axle extending from the transmission case 3, reference numeral 6 denotes a pair of left and right running wheels mounted on the axle 5, reference numeral 7 denotes a hitch for mounting a rotary work machine or the like, reference numeral 8 denotes a handle base mounted on the upper part of the transmission case 3, reference numeral 9 denotes a steering handle, reference numeral 10 Denotes a main transmission lever, 11 denotes an auxiliary transmission lever, 12 denotes an operation lever of a main clutch for turning on / off the transmission of power in the transmission case 4, 13
Reference numeral denotes an operation lever of a pair of left and right side clutches for turning on and off power transmission to the axle 5 in the transmission case 3. The transmission case 3 includes an input pulley 1 for inputting the power of the engine 1 as shown in FIGS.
5. PT for extracting power to the main transmission gear 19 and the working machine
An input shaft 21 having an O output shaft 20 and a shift fork 2
Shaft 23 that slides the main transmission gear 19 through the second fork shaft 23
, A counter shaft 25 provided with a reverse gear 24, and a main transmission shaft 28 provided with a first speed gear 26 and a second speed gear 27. The first speed gear 26 is rotatably supported on a main speed change shaft 28, and is provided with a counter shaft 25 via counter gears 29 and 30.
It is linked to. The counter shaft 25 is a counter gear 3
It is linked to the main transmission shaft 28 via 1 and 32. Thus, the main transmission mechanism 33 of two forward speeds and one reverse speed is configured, and the first forward speed is denoted by reference numerals 21, 19, 26, 29, 3
The second forward speed is code 2 in the order of 0, 25, 31, 32, 28.
In the order of 1, 19, 27, and 28, the reverse is denoted by reference numerals 21, 19,
Power is transmitted in the order of 24, 25, 31, 32, and 28, respectively. In FIG. 3, reference numeral 34 denotes a shift arm for linking the fork shaft 23 and the main speed change lever 10. 3 and 4, reference numeral 67 denotes a side clutch arm which is interlocked with the operation lever 13 of the side clutch via an operation wire 68. As shown in FIG. 6, the transmission case 3 supports an auxiliary transmission shaft 41 for transmitting power to the axle 5 via a sprocket 60 and a chain 64. Three rows of ball clutches 35, 36, 3
7, a low-speed output gear 4 provided on the main transmission shaft 28 side.
2. A low-speed gear 38, a medium-speed gear 39, and a high-speed gear 40 which always mesh with the medium-speed output gear 43 and the high-speed output gear 44, respectively.
Is pivotably supported. In the shaft of the auxiliary transmission shaft 41,
A shifter shaft 45 in which the first shaft portion 45a and the second shaft portion 45b are connected by a pin 45c is inserted movably in the axial direction, and each of the ball clutches 35, 36, 37 is mounted on the shifter shaft 45.
Is provided with a cylindrical sleeve 48 having a projection 46 for selectively engaging the sleeve 46. In this manner, the protrusion 46 is displaced by following the axial movement of the shifter shaft 45, and the low, medium and high speed gears 38 to 40 are transmitted via any of the ball clutches 35 to 37.
Is selectively engaged with the auxiliary transmission shaft 41, and the low speed, the medium speed,
A high-speed three-stage auxiliary transmission mechanism 47 is configured. In the above configuration, both ends of the shifter shaft 45 are projected outward in the width direction of the transmission case 3 so that both ends face the outside of the outer wall of the transmission case 3. A pair of shifter shaft moving operation mechanisms 60 and 70 for moving the shifter shaft 45 in the axial direction are provided. Specifically, around the axis of the shifter shaft 45,
As shown in FIGS. 6, 3, and 4, a pair of multi-stage cam surfaces A, B, C, D, E, and A are formed on the left and right wall surfaces of the transmission case 3 from which the shifter shaft 45 protrudes. , B,
Fixed cam body having C, D and E (hereinafter referred to as fixed cam)
49 and 490 are fixed via the detent pins 51.
Further, a pair of rollers 50 abutting against the multi-stage cam surfaces A, B, C,...
a, 50b, a shaft body 50c that rotatably supports the rollers 50a, 50b, and a sub-transmission arm 50d that connects a pair of operation wires 55, 550 extending from the sub-transmission lever 11, and a roller-type movable cam. 50 and 500 are attached via screws 52 and nuts 53, respectively. Thus, each of the fixed cams 49, 490 and the movable cams 50, 500
Thus, the shifter shaft moving operation mechanisms 60 and 70 are configured. As shown in FIG. 6, the multi-stage cam surfaces of the fixed cams 49 and 490 are, as shown in FIG. 6, a first cam floor A, a second cam floor C, and a third cam floor E. And tapered surfaces B and D formed by inclined surfaces connecting the two. The fixed cams 49 and 490 are made of iron or zinc, and the rollers 50a and 50b are made of SS40.
It is formed of an alloy steel such as 0. As shown in FIGS. 7 and 8, the auxiliary transmission lever 11 for operating the movable cams 50 and 500 is supported by a bracket 90 fixed to the steering handle 9 via a support shaft 91. The inner shaft portions 91a and 91b protruding from both ends of the support shaft 91 and a pair fixed to the same by a one-stroke swing operation of the auxiliary speed change lever 11 by a one-way rotation transmission mechanism such as a one-way clutch built in the shaft 91. The cam plates 92 and 93 are rotated by a certain angle, and each cam plate 9 is rotated.
The swing arms 96 and 97 that support the rollers 94 and 95 abutting on the outer peripheral portions of the swing arms 96 and 97 are swung around the swing shafts 98 and 99, and coil springs are attached to the ends of the swing arms 96 and 97. Each operation wire 55,
The 550 inner members 55a, 550a are moved forward and backward. Each of the cam plates 92 and 93 has a ridge 92 on the long axis side.
a and 93a are formed by having valleys 92b and 93b on the minor axis side and making one major axis coincide with the other minor axis.
The cam plate 9 is disposed so as to be displaced by 0 degrees.
When the second valley portion 92b is in contact with the roller 94 and is in a position where the contact position is gradually changed toward the peak portion 92a by operating the sub-transmission lever 11, the peak of the cam plate 93 on the other side is set. The portion 93a is in contact with the roller 95, and is in a position where the contact position is to be sequentially changed toward the valley portion 93b by operating the auxiliary speed change lever 11. In FIG. 7, reference numeral 81 denotes an operation wire 5
5 and 550 are outer supports for supporting the outer 55b and 550b, and are fixed to the left and right connecting bar 80 of the steering handle 9. Reference numerals 82 and 83 denote lever-rotation-angle positioning holes provided in each of the cam plates 92 and 93 so as to be engaged with a ball-entry type positioner 84. Reference numeral 85 denotes a gear position indicator piece protruding from the upper end of one swing arm 97. In FIG. 8, reference numeral 86 denotes a return spring of the sub-transmission lever 11, and 87 and 88 denote stoppers for regulating the swing dead center of the sub-transmission lever 11. In this manner, when the one operation wire 55 is operated in the pulling direction by the swing operation of the sub-transmission lever 11, the other operation wire 550 is operated in the loosening direction,
By such reversible forward and backward movements, the movable cams 50, 70 in the shifter shaft moving operation mechanisms 60, 70 described above.
The shifter shaft 45 is reciprocated in the axial direction while free movement of both ends of the shifter shaft 45 is restricted. FIG. 9 shows a second embodiment, in which the movable cam 5
0,500 is not a roller type but has a cam piece 57,570 in a trapezoidal shape in a side view and an arc shape in a plan view.
The shifter shaft 45 can be reciprocated by contact between the cam surfaces of the cam pieces 57 and 570 with the cam pieces 57 and 570. FIG. 10 shows a third embodiment, in which a shifter shaft 4
Operation wires 5 reversibly moving forward and backward at both ends of
The shifter shaft moving operation mechanisms 60 and 70 are configured by directly coupling the shifters 5 and 550. In this configuration, the configuration can be simplified. Reference numerals 58 and 59 denote oil seals, and reference numerals 31 and 32 denote extension cylinder portions that receive both ends of the shifter shaft 45. According to the first aspect of the present invention, while having the advantage of being able to shift without a clutch using a ball clutch, the shifter shaft for performing the shift is moved by the roller and fixed cam body. Is performed by sliding contact with the multi-stage cam surface, the resistance applied when the shifter shaft is moved can be reduced, and the shift operability can be improved. [0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of an agricultural machine equipped with a transmission according to the present invention. FIG. 2 is a plan view of the agricultural working machine. FIG. 3 is a left side view of a main part of the transmission. FIG. 4 is a right side view of a main part of the transmission. FIG. 5 is an upper sectional view of the transmission. FIG. 6 is a lower sectional view of the transmission. FIG. 7 is a perspective view of a lever portion for operating the transmission. FIG. 8 is a sectional view of the lever portion. FIG. 9 is an essential part cross-sectional view showing a second embodiment of the transmission. FIG. 10 is an essential part cross sectional view showing a third embodiment of the transmission. [Description of Signs] 3; transmission case 41; transmission shaft (sub transmission shaft) 3
5, 36, 37; ball clutches, 38, 39, 40;
Constant meshing transmission gear, 45; shifter shaft, 46; projection, 4
9,490; fixed cam, 50,500; movable cam, 5
5,550; operation wire, 60, 70; shifter shaft moving operation mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-217037 (JP, A) JP-A-5-149397 (JP, A) Fully open 1981-37748 (JP, U) Really openly 3- 35367 (JP, U) (58) Fields studied (Int. Cl. ⁷ , DB name) F16H 61/26-61/36 F16H 63/00-63/38

Claims (1)

(57) Patent Claims 1. A through <br/> a ball clutch in the transmission case and rotatably supporting the plurality of shift gearing disengaged freely, have a hollow hole
Shifter shaft having a shift shaft which is inserted through movably in the hollow hole, a collision force to engage operating the <br/> ball clutch
Are arranged around the axis of the shifter shaft, and
A fixed cam body having a stepped cam surface and abutting on the multi-step cam surface
And, by the transmission of the agricultural <br/> industry machine having an operation member operated to move the shifter shaft, both ends of the shifter shaft is protruded to the outside of the <br/> transmission cases, At both ends
Around, the multi-stage cam surface is opposite to the mission case
The fixed cam bodies are respectively arranged so that
The crop is supported at both ends, and each fixed cam is multi-staged.
The shifter shaft is moved to one side and the other while abutting on the cam surface.
A transmission for an agricultural work machine, comprising: