JP3565612B2 - Mission structure of walking machine - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a walk-behind work machine such as a tailor, a management machine, and a binder, and more particularly, to a technique for compactly configuring a multi-stage transmission for traveling.
[0002]
[Prior art]
For example, when it is desired to set four or more forward gears, conventionally, a three-stage forward and one-stage reverse transmission is used to switch between a high and low belt transmission mechanism spanning the input shaft and the engine shaft. There has been a means for obtaining six forward speeds and two reverse speeds by means of a sub-speed change using a so-called double tension clutch. There has also been a means for utilizing a two-stage forward and two-stage reverse mission and providing a sub-transmission mechanism in the mission to obtain four forward and four reverse stages.
[0003]
[Problems to be solved by the invention]
In the former means, the space for disposing the double tension clutch is large, and the overall size of the transmission is increased.In addition, in the latter means, in order to obtain the necessary number of forward gears, the number of actually unnecessary reverse gears is set. As a result, the size of the mission case becomes unnecessarily large, and there is room for improvement by any means.
Therefore, as in the walking type working machine disclosed in Japanese Utility Model Laid-Open Publication No. 4-11064, a required multi-stage forward movement is provided by providing a main transmission mechanism having three forward steps and one reverse step and a sub-transmission mechanism having two high and low steps. There is known a technology in which the entire transmission is comparatively miniaturized while providing a transmission and a reverse, and a total of three shift operation sections can be operated with one shift lever.
SUMMARY OF THE INVENTION An object of the present invention is to further reduce the size and simplification of a new transmission having six forward speeds and two reverse speeds to make the transmission more rational.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a vertically long traveling transmission case having an engine power input shaft at an upper portion and a drive axle at a lower end portion, with an engine at a front part of a fuselage and a hitch at a rear part of a body. In the mission structure of the walk-behind work machine arranged between
A plurality of transmission shafts are arranged in the vicinity of the input shaft, and a sub-transmission mechanism capable of switching between high and low stages between the input shaft and each transmission shaft, and a forward / reverse rotation capable of switching between first forward rotation and reverse rotation. By arranging the switching mechanism and a forward rotation transmission mechanism capable of switching between the second forward rotation and the third forward rotation, a traveling transmission portion capable of selecting six forward speeds and two reverse speeds is configured,
A transmission rotating body externally fitted to the input shaft so as to be relatively rotatable; and a first shift gear constituting the auxiliary transmission mechanism externally fitted to the input shaft so as to be integrally rotated,
A second shift gear constituting the forward / reverse switching mechanism and a third shift gear constituting the forward rotation mechanism are externally fitted to the transmission rotating body so as to rotate integrally and slidably;
A first transmission shaft of the plurality of transmission shafts is provided with a drive gear that meshes with a driven gear of the transmission rotating body, and a passive gear that rotates integrally with the drive gear, and the first shift gear is connected to the input shaft. In contrast, the sub-transmission mechanism is configured by being slidably fitted over an engagement position with the driven gear and an engagement position with the passive gear,
A back gear that can mesh with the second shift gear in the forward / reverse switching mechanism is fitted to the first speed change shaft so as to be relatively rotatable .
[0005]
Conveniently, the tip of the input shaft projects from the transmission case, and the projecting portion is formed as a power take-out portion for driving the working device.
[0006]
Further, the first shift gear is slidably operated, and the first shift shaft on which the first shift gear is slid, and the inclined groove and the pin fitted and engaged in the inclined groove are separately formed on the first shift shaft. A tilt cam mechanism capable of sliding the first shifter by rotating the shaft,
The second shifter for operating the second shift gear and the third shifter for operating the third shift gear are configured to be individually shiftable by a cross swing operation of a shift lever, and the shift lever is operated by a cross swing operation. The tilt cam mechanism is configured to be switchable by a large swing operation larger than the operation amount of, and the shift lever and the shift lever are arranged so that the cross swing operation can be performed at each of both swing ends of the large swing operation. It is more preferable that a speed change operation linking mechanism for linking the tilt cam mechanism with the second and third shifters is provided.
Further, a drive gear body that swings integrally with the shift lever around a swing fulcrum of the shift lever, and a driven gear body that is mounted on the first shift shaft in a state of being engaged with and interlocking with the drive gear body, It is advantageous if a gear amplifying mechanism is configured to amplify the swing operation angle of the speed change lever and transmit it to the first shift shaft.
[0007]
[Action]
According to the first aspect, it means that are fitted three shift gear to the input shaft, that they are compared to a case which is arranged in a dispersed, to reduce the space requirement gearshift operating part This contributes to the miniaturization of the mission case. That is, since the mechanisms necessary for the three shift operations can be arranged collectively, for example, compared to the case where these shift gears are dispersedly arranged, the space necessary for the moving members such as the shifters is shared, and The required space can be reduced.
[0008]
The high speed state of the auxiliary transmission mechanism appears by a direct connection of the transmission rotator and the first shift gear on the input shaft, and the low speed state transmits the rotation by bypassing the two-stage gear between the transmission rotation body and the first shift gear. Since it appears by power transmission to the body, the number of required shafts can be reduced by one by using the transmission shaft as a shaft for back gear support. That is, the first and second shift gears of the forward / reverse switching mechanism and the forward transmission mechanism are externally fitted on the input shaft via a first shift gear of the auxiliary transmission mechanism and a transmission rotating body which is externally rotatably fitted on the input gear. As a result, since all the shift gears are arranged on the input shaft in a centralized manner, the low-speed bypass of the subtransmission mechanism and the back gear can be arranged without overlapping.
[ 0009 ]
According to the configuration of the second aspect, the input shaft becomes the power take-out shaft as it is, so that high rotational power suitable for the working device can be transmitted without having a dedicated relay shaft.
Further, since the shaft is supported by a relatively long span in which three shift gears are fitted, the rotation of the input shaft serving also as the power take-out shaft can be stably taken out.
[0010]
According to the configuration of the third aspect , the height of the sub-transmission mechanism is selected first by a large swing operation of the shift lever, and a desired gear can be obtained by the cross swing operation in the selected state. All gear shifting operations can be performed only with this lever. The fact that the sub-shift can be switched by the rotation of the first shift shaft by the tilt cam mechanism enables a large swing operation of the shift lever, and the shift operation can be performed in comparison with the above-mentioned publication (Japanese Utility Model Laid-Open No. 4-11064). Single lever operation was realized while reducing the required space of the unit.
[0011]
According to the configuration of the fourth aspect , since the first shift shaft needs to be relatively largely rotated to operate the tilt cam mechanism, the operation stroke of the shift lever is reasonably amplified by the gear amplifying mechanism to perform the first shift. It can be converted into rotation of the shaft. For example, as shown in FIG. 10, a means may be considered in which the short arm 41 of the first shift shaft 15 and the long arm 42 of the speed change lever 33 are engaged with the pin 43 so as to amplify and interlock with each other. The point, that is, the radius of the contact point between the pin 43 and the short arm 41 (or the long arm 42) changes, and there is a poor shift feeling in which the first shift shaft 15 rotates in a sine curve. Is preferable in that the phenomenon does not occur.
[0012]
【The invention's effect】
In the transmission structure according to the first aspect of the present invention, a multi-stage shift stage of six forward speeds and two reverse speeds is compactly formed in the upper part of the transmission case by an integrated arrangement structure in which three shift gears are fitted to one input shaft. I was able to. Further, an advantage that the size can be further reduced by reducing the number of shafts for shifting is added.
In the transmission structure according to the second aspect, an advantage that a stable high-speed power take-out can be obtained while a multi-speed transmission can be obtained compactly.
In the transmission structure according to the third aspect , it is possible to perform a multi-stage shift operation with a single shift lever while saving space in the shift operation section.
The transmission structure described in claim 4 has an additional advantage that the shift operation feeling of the subtransmission mechanism is improved.
[0013]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a two-wheel type tailor as a walk-behind work machine, 1 is a drive wheel, 2 is a transmission case, 3 is a steering handle, 4 is a hitch, 5 is a work device, and 6 is a sub-chain case. The mounting frame 7 on which the engine E is mounted and the frame frame 8 to which the hitch 4 is attached are both bolted to the transmission case 2 and integrated to form an airframe.
The power from the engine E is transmitted to the input shaft 10 of the transmission M by the double belt interlocking mechanism 9 to drive both the drive axle 11 and the working device 5. Next, the structure of the mission M will be described.
[0014]
As shown in FIGS. 2 to 5, a gear transmission unit (running transmission unit) A is provided at the upper part of the transmission case 2, and an axle transmission unit B that transmits a chain between the output shaft 12 and the drive axle 11 of the gear transmission unit A. It has. Then, the transmission case 2 is set to the forward leaning posture such that the reference straight line L passing through two points of the rotation axis Q of the output shaft 12 and the rotation axis P of the drive axle 11 is closer to the rear of the fuselage. In addition, a gear transmission portion A is disposed on the rear side with respect to the reference straight line L.
[0015]
The gear transmission section A includes four input shafts 10, a first transmission shaft 13, a second transmission shaft 14, and an output shaft 12, and includes a first shift shaft 15, a second shift shaft 16, a third shift shaft 17, And a two-stage auxiliary transmission mechanism C, a forward / reverse transmission mechanism D capable of switching between first forward speed and reverse, and a forward transmission mechanism F capable of switching between second forward speed and third forward speed. , 6 forward speeds and 2 reverse speeds.
[0016]
The auxiliary transmission mechanism C includes a transmission rotator 18 that is fitted to the input shaft 10 so as to be relatively rotatable, a first shift gear 19 that is fitted to the input shaft 10 by a spline, a driven gear 18A of the transmission rotator 18, It is provided with a passive gear 20 and a drive gear 21 of one speed change shaft 13. When the first shift gear 19 is shifted to the right in FIG. 3 to engage with the internal gear portion 18a of the driven gear 18A, a high speed stage appears, and the first shift gear 19 is shifted to the left in FIG. A low speed step appears when it is occluded.
[0017]
The forward / reverse transmission mechanism D includes a second shift gear 22 that is splined to the transmission rotating body 18, a back gear 23 that is fitted to the first transmission shaft 13 as a bearing, and a fork that is loosely fitted to the second transmission shaft 14. And a gear 24. The small-diameter gear portion 23b of the back gear 23 and the large-diameter gear portion 24a of the trifurcated gear 24 are always meshed, and the second shift gear 22 is shifted rightward in FIG. When the second shift gear 22 is shifted to the left in FIG. 3 when the second shift gear 22 is shifted to the left in FIG. .
[0018]
The forward rotation transmission mechanism F includes a third shift gear 25 that is fitted outside the spline to the transmission rotating body 18, and a forked gear 24 of the second transmission shaft 14. When the third shift gear 25 is shifted to the right in FIG. 3 and its large-diameter gear portion is engaged with the small-diameter gear portion 24c of the trifurcated gear 24, a third forward speed (or sixth speed) appears, and the third shift gear 25 is shifted. When the gear portion is shifted to the left in FIG. 3 and the small-diameter gear portion is engaged with the medium-diameter gear portion 24b of the trifurcated gear 24, the second forward speed (or the fifth speed) appears.
A brake 26 and a pair of left and right side clutches 27 are provided at the end of the second transmission shaft 14.
[0019]
Next, the shift operation structure will be described.
As shown in FIGS. 3 and 5, the first shifter 28 for operating the first shift gear 19 is on the first shift shaft 15, the second shifter 29 for operating the second shift gear 22 is on the second shift shaft 16, and The third shifters 30 that operate the three shift gears 25 are respectively fitted to the third shift shafts 17.
The forward / reverse speed change mechanism D and the forward speed change mechanism F have a general operation structure that is switched by pushing and pulling the second and third shift shafts 16 and 17 in the axial direction. The structure is switched by rotating one shift shaft 15.
[0020]
That is, as shown in FIG. 3, a pair of substantially Z-shaped inclined grooves 31 are formed in the cylindrical boss portion 28 a of the first shifter 28 at the axially symmetric positions in a developed state, and the pins 32 fitted and engaged in the inclined grooves 31 are formed. A pair of inclined cam mechanisms G are mounted on the first shift shaft 15 and are capable of shifting (sliding) the first shifter 28 by the rotation of the first shift shaft 15.
[0021]
As shown in FIGS. 6 to 9, the first to third shift shafts 15, 16, and 17 are configured to be switchable by one shift lever 33. As shown in FIG. 2, the input shaft 10 and the first and second transmission shafts 13 and 14 are arranged in a triangular shape, and the three shift shafts 15, 16 and 17 are arranged in a triangular shape above the input shaft 10 in a state of approaching each other. Have been.
The operating portion 33A of the speed change lever 33 is supported on the operation body 34 which is swingable about the left and right axis X behind the first shift shaft 15 so as to be swingable about the vertical axis Y. Are supported by the transmission case 2 so as to be able to perform a cross swing operation.
[0022]
The operating body 34 is integrally formed with a driving gear body 36 that meshes with a driven gear body 35 mounted on the first shift shaft 15. 15 constitutes a gear amplifying mechanism H that transmits the gears.
The second shift shaft 16 is provided with a second operated body 16A, and the third shift shaft 17 is provided with a third operated body 17A. A long pin 37 and a short pin 38 which can be engaged with these are plate-shaped. Is attached to the curved portion of the operation section 33A.
[0023]
Next, a procedure of a shift operation by the shift lever 33 will be described.
First, when the shift lever 33 is swung downward and is operated in the low speed range Lo in the lever guide 39, the sub-amplifying mechanism C is switched to the low speed stage by the operation of the gear amplifying mechanism H. 37 selects the second operated body 16A (at this time, the short pin 38 is not located on any of the operated bodies 16A and 17A), and in this state (the state of FIGS. 6 and 9), the shift lever 33 is moved. If the swing operation is performed in the left-right direction, the first reverse speed or the first forward speed can be obtained. When the shift lever 33 is slightly raised and swung from this state, the long pin 37 selects the third operated body 17A (at this time, the short pin 38 is not located on any of the operated bodies 16A, 17A). In this state, if the shift lever 33 is swung in the left-right direction, the second forward speed or the third forward speed can be obtained.
[0024]
Next, when the shift lever 33 is greatly moved upward and swings to operate in the high-speed range Hi past the neutral range N, the sub-amplification mechanism C is switched to the high-speed stage by the operation of the gear amplifying mechanism H, and the short pin 38 The second operated body 16A is selected (at this time, the long pin 37 is not located on any of the operated bodies 16A and 17A), and then the shift lever 33 is swung left and right to change the fourth forward speed or the second reverse speed. can get. Then, when the shift lever 33 is swung to the upper limit, the short pin 38 selects the third operated body 17A (the state shown in FIG. 7, and also at this time, the long pin 37 is connected to both the operated bodies 16A and 17A). 5), and the fifth or sixth forward speed can be obtained by swinging the shift lever 33 right and left.
[0025]
Protrusions 40 and 40 are formed on the upper side of the second operated body 16A and the lower side of the third operated body 17A, respectively. The vertical stroke of the speed change lever 33 is restricted by the contact between the pin 37 and each projection 40.
In short, the second shifter 29 and the third shifter 30 are configured so that the shift operation can be individually performed by the cross swing operation of the shift lever 33, and the shift lever 33 is moved in the vertical direction that is larger than the operation amount of the cross swing operation. The tilting cam mechanism G is configured to be able to be switched by a swinging operation, and the selecting operation of the second and third shifters 29 and 30 is performed at each of both swinging ends of the large swinging operation. A shift operation linking mechanism I for linking the shift lever 33, the tilt cam mechanism G, and the second and third shifters 29, 30 is configured to enable the operation.
[0026]
As shown in FIG. 3, the tip of the input shaft 10 penetrates the transmission case 2 and protrudes to the outside, and a spline is formed there, and is also used as a power take-out portion (PTO shaft) 44. The sub-chain case 6 shown in FIG. 1 utilizes the power take-out portion 44. Further, as described above, the first speed change shaft 13 supporting the bypass (passive gear 20 and drive gear 21) for causing the low speed stage in the auxiliary speed change mechanism C to function also serves as the back shaft for supporting the back gear 23. As a result, the number of transmission shafts is as small as three, that is, the input shaft 10 and the first and second transmission shafts 13 and 14, but a multi-stage transmission with six forward speeds and two reverse speeds is possible. Have been.
[0027]
(Another embodiment)
If three shift gears are fitted on the input shaft 10, for example, a high, middle, and low three-stage auxiliary transmission mechanism C may be used as a nine-stage forward and three-stage reverse transmission.
[0028]
Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.
[Brief description of the drawings]
FIG. 1 is a side view of a tailor. FIG. 2 is a side view showing a transmission case shape. FIG. 3 is a cross-sectional rear view of a transmission showing a structure of a traveling transmission unit. FIG. 4 is a cross-sectional rear view of a transmission showing a structure of an axle transmission unit. FIG. 5 is an exploded view showing the structure of the speed change operation unit. FIG. 6 is a side view showing a speed change operation linkage mechanism in a low speed state of the auxiliary speed change mechanism. FIG. 7 is a view showing a speed change operation linkage mechanism in a high speed state of the auxiliary speed change mechanism. FIG. 8 is a plan view showing the structure of a speed change operation unit. FIG. 9 is a view showing a lever guide. FIG. 10 is a side view showing a comparative example of a rotation operation structure of a first shift shaft.
2 Transmission case 4 Hitch 10 Input shaft 11 Drive axle 13 Transmission shaft 14 Transmission shaft 15 First shift shaft 18 Transmission rotating body 18A Follower gear 19 First shift gear 20 Passive gear 21 Drive gear 22 Second shift gear 23 Back gear 25 Third shift gear 28 1st shifter 29 2nd shifter 30 3rd shifter 31 Inclined groove 32 Pin 33 Shift lever 35 Follower gear body 36 Drive gear body 44 Power take-out part A Travel transmission part C Subtransmission mechanism D Forward / reverse switching mechanism E Engine F Forward rotation Mechanism G Inclined cam mechanism H Gear amplifying mechanism I Shift operation linking mechanism X Swing fulcrum

Claims (4)

A longitudinal transmission case (2) having an engine power input shaft (10) at an upper portion and a drive axle (11) at a lower end portion is provided with a front engine (E) and a rear hitch. (4) a transmission structure of the walking type working machine disposed between
A plurality of speed change shafts (13) and (14) are arranged near the input shaft (10), and two high and low speed stages are provided across the input shaft (10) and the speed change shafts (13) and (14). A switchable auxiliary transmission mechanism (C), a forward / reverse switching mechanism (D) capable of switching between first forward rotation and reverse rotation, and a forward rotation transmission mechanism (switchable between second forward rotation and third forward rotation) F) to form a traveling transmission unit (A) capable of selecting six forward speeds and two reverse speeds,
A transmission rotating body (18) externally fitted to the input shaft (10) so as to be relatively rotatable, and a first transmission mechanism (C) constituting the auxiliary transmission mechanism (C) externally fitted to the input shaft (10) so as to rotate integrally therewith. A shift gear (19),
A second shift gear (22) constituting the forward / reverse switching mechanism (D) and a third shift gear (25) constituting the forward rotation mechanism (F) are integrally rotated with the transmission rotating body (18), and Sliding fit outside,
A drive gear (21) meshing with a driven gear (18A) of the transmission rotating body (18) on a first transmission shaft (13) of the plurality of transmission shafts (13) and (14); And a passive gear (20) that rotates integrally with the driven gear (18). The first shift gear (19) is engaged with the input shaft (10) with the driven gear (18A) and the passive gear (20). 20), the auxiliary transmission mechanism (C) is configured to be slidably fitted over the occlusal position with
A transmission structure of a walking-type working machine in which a back gear (23) capable of engaging with the second shift gear (22) in the forward / reverse switching mechanism (D) is relatively rotatably fitted to the first transmission shaft (13). . The walking type working machine according to claim 1, wherein a tip of the input shaft (10) protrudes from the transmission case (2), and the protruding portion is configured as a power take-out portion (44) for driving a working device. Mission structure. A first shifter (28) that can slide the first shift gear (19), a first shift shaft (15) into which the first shift gear (19) is fitted, an inclined groove (31), and a fitting member that fits into the inclined groove (31). A tilt cam mechanism (G) capable of slidably operating the first shifter (28) by the rotation of the first shift shaft (15) by distributing and forming the pin and the mating pin (32),
The second shifter (29) for operating the second shift gear (22) and the third shifter (30) for operating the third shift gear (25) are separately moved by the cross swing operation of the shift lever (33). The shift lever (33) is configured to be capable of shifting operation, and the tilt cam mechanism (G) is configured to be switchable by a large swing operation that is equal to or greater than the operation amount of the cross swing operation. The shift lever (33), the tilt cam mechanism (G), the second and third shifters (29), () so that the cross swing operation can be performed at each of both swing ends of the swing operation. The transmission structure of a walking-type working machine according to any one of claims 1 and 2, further comprising a speed change operation linking mechanism (I) that links the speed change operation link (30). A drive gear body (36) swinging integrally with the shift lever (33) about a swing fulcrum (X) of the shift lever (33), and in a state in which the drive gear body (36) is engaged with and interlocked with the drive gear body (36). A gear amplifying mechanism for amplifying the swing operation angle of the speed change lever (33) and transmitting the swing operation angle to the first shift shaft (15) by a driven gear body (35) mounted on the first shift shaft (15). The transmission structure of a walking-type working machine according to claim 3 , wherein (H) is constituted.

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