JP2907593B2 - Transmission structure of riding rice transplanter - 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 structure of a riding type rice transplanter having an engine at a front portion of a body and a seedling planting device at a rear portion of the body.

[0002]

2. Description of the Related Art In this type of riding type rice transplanter, a seedling planting device, which is a working device having a large weight ratio to the entire body weight, is provided behind a rear wheel at the rear of the machine body. Since it is necessary to balance the weight of the engine, it is common to install a heavy engine at the front of the fuselage as much as possible. The riding type rice transplanter is provided with a hydraulic pump for driving the raising and lowering of the seedling planting device. The hydraulic pump is used at a relatively high speed and a constant speed for the purpose of being used in an efficient state. They tend to be used in a driven configuration. For this reason, it is common to arrange | position near an engine so that engine power may be directly transmitted, without interposing a transmission in the middle of the transmission system to a hydraulic pump. In addition, the riding type planting machine is intended for work in wet fields, and in order to reduce the weight of the body as much as possible, increase the weight as in the case where the entire traveling transmission mechanism is constituted by a gear type transmission mechanism. The structure is not difficult to avoid, and a reduction in the weight of the transmission mechanism is also required, and those using a belt-type continuously variable transmission are used. The following [1] and [2] are known as transmission structures of a riding type rice transplanter equipped with the above-described belt-type continuously variable transmission. .. [1] A belt-type continuously variable transmission disposed at the front of the body is directly connected to an output shaft of an engine provided at the front of the body, and the output from the belt-type continuously variable transmission is transmitted to the transmission shaft. (See, for example, Japanese Utility Model Laid-Open Publication No. 64-55129). .. [2] The output from the engine provided at the front of the fuselage is branched into two systems, one of which is connected to a hydraulic pump at the front of the fuselage, and the other is a belt-type continuously variable at the rear of the fuselage via a transmission shaft A transmission configured to be transmitted to the transmission (for example, see Japanese Utility Model Laid-Open No. 63-150147).

[0003]

The belt-type continuously variable transmission described in the prior arts [1] and [2] has a pair of pulley portions (a fixed pulley portion and a movable pulley portion) opposed to each other. Pulley part) is 2
A set of split pulleys, a transmission belt wound around the two sets of split pulleys, a shift operation mechanism for moving the pulley portion on the moving side of one split pulley, and the other split pulley Is provided with a spring mechanism for urging the pulley portion on the moving side toward the near side. This allows
When the moving pulley portion of one split pulley is moved to the low speed side and the high speed side by the speed change operation mechanism, the tension of the transmission belt and the urging force of the spring mechanism are balanced with the other, so that the other side is balanced. The pulley part on the moving side of the split pulley moves. In such a belt-type continuously variable transmission, when the moving pulley portion is moved by the speed change mechanism with respect to the fixed pulley portion of one split pulley, the winding radius of the transmission belt of one split pulley is reduced. At the same time as the speed change is performed, the transmission belt itself slightly moves in the direction of the rotation axis of the split pulley with the movement of the pulley portion on the moving side. In this case, if the pulley portion on the moving side of the other split pulley is configured to be biased toward the near side by a spring mechanism, when the above-described speed change is performed, the tension of the transmission belt and the aforementioned It takes a little time for the biasing force of the spring mechanism to equilibrate, and the pulley portion (spring mechanism side) on the moving side of the other split pulley cannot move quickly and moves a little later. There are many. As described above, if the movement of the pulley portion (spring mechanism side) on the moving side of the other split pulley is delayed with respect to the movement of the pulley portion (shifting operation mechanism side) on the moving side of the one split pulley, The shift of the positional relationship between the pulley portions on both moving sides of the split pulley causes the transmission belt to be slightly bent (the transmission belt is wound around one split pulley and is wound around the other split pulley). Parts are not located on the same plane orthogonal to the rotation axis of the split pulley). Therefore, if the state where the transmission belt is slightly bent occurs every time the gear is shifted, the durability of the transmission belt may be reduced.

Further, as described in the prior art described in the above [1], an output shaft of an engine provided at a front portion of the body is provided with:
The belt type continuously variable transmission arranged directly in front of the fuselage is directly connected, and the output from the belt type continuously variable transmission is configured to be input to the transmission case at the rear of the aircraft via the transmission shaft. There has been a problem that the rotational torque of the transmission shaft whose rotational speed has been reduced through the continuously variable transmission becomes large, the transmission length becomes long, and the shaft weight increases. When the belt-type continuously variable transmission is disposed at the rear of the body away from the engine as in the related art described in [2], an increase in the weight of the transmission shaft as in the case of [1] can be avoided. It is advantageous in that respect. However, in this prior art, since the hydraulic pump is disposed near the engine at the front side of the fuselage, the heat of the engine section reaches the hydraulic pump, or conversely, the influence of the heat generated by the hydraulic pump affects the engine section. This is disadvantageous in that the mutual heat radiation effect is hindered. In addition, the output from the engine is branched into two systems, a front side and a rear side, and transmitted to the hydraulic pump and the belt-type continuously variable transmission at the rear of the machine body. The number of components tends to increase, which tends to increase costs and weight.

SUMMARY OF THE INVENTION The present invention provides a transmission structure of a riding type rice transplanter which, when provided with a belt type continuously variable transmission, prevents the overall durability of the belt type continuously variable transmission from decreasing. It is intended to simplify the transmission structure and the hydraulic system structure of the machine.

[0006]

SUMMARY OF THE INVENTION A feature of the present invention is that an engine is provided at a front portion of a fuselage, an output from the engine is transmitted to a rear wheel at a rear portion of the fuselage away from the engine, and a seedling is provided behind a rear axle. The transmission structure of a riding type rice transplanter provided with an implanting device is configured as follows. A first split pulley and a second split pulley in which a pair of pulley portions facing each other can approach and separate from each other;
A transmission belt wound around the split pulley to form a belt-type continuously variable transmission, wherein the belt-type continuously variable transmission includes a pulley portion on both moving sides of the first and second split pulleys. A transmission operation mechanism that shifts the gear by moving to the same low-speed side and high-speed side, and a transmission case including a transmission mechanism for transmitting the power from the engine to the rear wheels. A hydraulic pump is disposed in the vicinity of the transmission case and the belt-type continuously variable transmission, and an input shaft of the belt-type continuously variable transmission is connected to the hydraulic pump. The hydraulic pump is driven by the power transmitted to the hydraulic pump, and the hydraulic pump discharges using the lubricating oil of the transmission case as hydraulic oil.

Further, as set forth in claim 2, a case may be provided for covering the belt-type continuously variable transmission.

[0008]

According to a first aspect of the present invention, there is provided a belt-type continuously variable transmission including a first split pulley and a second split pulley in which a pair of pulley portions facing each other can freely move close to and away from each other.
And the pulley portion on both the moving side of the 20% pulley,
A shift operation mechanism is provided for moving to the same low speed side and high speed side. Therefore, if the moving pulley portions of both the first and second split pulleys are moved, the moving pulley portions of both the first and second pulleys can be moved simultaneously. Compared to a configuration in which the pulley portion on one moving side is biased to the near side by a spring mechanism, the movement of the pulley portion on the other moving side is delayed with respect to the movement of the pulley portion on the other moving side. No condition occurs.

[II] According to the first aspect of the present invention, the belt-type continuously variable transmission is arranged in a transmission system near a transmission case provided at a rear portion of the vehicle body, away from an engine at a front portion of the vehicle body. . This allows
The belt-type continuously variable transmission can be easily and easily supported on the fixed portion without being affected by vibration, heat, or the like of the engine. Further, since it is difficult for the vibration and heat of the engine to be directly transmitted to the belt-type continuously variable transmission, it is possible to prevent the durability of the belt-type continuously variable transmission from decreasing due to the vibration and heat of the engine.

[III] According to the first aspect of the present invention, since the hydraulic pump is disposed near the transmission case and the belt-type continuously variable transmission provided at the rear part of the body, the lubricating oil of the transmission case is supplied with the hydraulic oil. When the hydraulic pump is configured to discharge, the supply system of the hydraulic oil from the transmission case to the hydraulic pump becomes short, and the supply system is not arranged by sewing between various structures. Also, it is possible to easily arrange the hydraulic oil supply system from the transmission case to the hydraulic pump with a short system.

When a seedling planting device is provided at the rear of the body, a hydraulic mechanism (for example, a hydraulic cylinder or the like) for raising and lowering the seedling planting device is also provided at the rear of the machine. As a result, when the hydraulic pump is disposed near the transmission case and the belt-type continuously variable transmission provided at the rear of the body, the hydraulic pump is located near the hydraulic mechanism. Therefore, the supply system of the hydraulic oil from the hydraulic pump to the hydraulic mechanism can be easily shortened as described above. As described above, if the supply system of the hydraulic oil from the hydraulic pump to the hydraulic mechanism is shortened, the pressure loss between the hydraulic pump and the hydraulic mechanism can be suppressed to a small value, and the hydraulic oil from the hydraulic pump can be reduced. Is used in the hydraulic mechanism without waste.

According to the first aspect of the present invention, when the hydraulic pump is disposed near the transmission case and the belt type continuously variable transmission provided at the rear part of the body, the belt type continuously variable transmission according to the above item [II]. As in the case of (1), the vibration, heat, etc. of the engine at the front part of the fuselage are difficult to be directly transmitted to the hydraulic pump, and the deterioration of the durability of the hydraulic pump due to the vibration, heat, etc. of the engine can be prevented.

[IV] As described in the preceding items [II] and [III], the belt-type continuously variable transmission and the hydraulic pump are separated from the engine at the front part of the body and are located near the transmission case provided at the rear part of the body. When the hydraulic pump is disposed near the belt type continuously variable transmission, it is easy to connect the input shaft of the belt type continuously variable transmission to the hydraulic pump by disposing the hydraulic pump near the belt type continuously variable transmission. Therefore, the drive structure of the hydraulic pump can be simply configured. When a speed change is performed in the belt-type continuously variable transmission, the rotation speed of the output shaft of the belt-type continuously variable transmission changes, whereas the rotation speed of the input shaft of the belt-type continuously variable transmission does not change. Thus, according to the first aspect of the present invention, the hydraulic pump is driven at a substantially constant rotational speed even when a shift is performed in the belt-type continuously variable transmission.

[V] According to the second aspect of the present invention, there is provided a case for covering the belt-type continuously variable transmission, which prevents adhesion of muddy water or the like to the belt-type continuously variable transmission. It can also be expected that the noise generated by the continuously variable transmission is suppressed. In general, a riding type rice transplanter generally adopts a structure in which an engine provided at a front portion of the fuselage is supported by anti-vibration rubber or the like so that vibration of the engine is not transmitted to a driving unit through the fuselage. Looking at this structure from another point of view, the engine is allowed to vibrate relative to the airframe. Therefore, in the riding type rice transplanter having such a structure, it is difficult to directly connect the belt-type continuously variable transmission covered by the case to the output shaft of the engine in terms of the case supporting structure and the like. However, in the present invention, the belt-type continuously variable transmission covered by the case is disposed in the transmission system near the transmission case, away from the engine at the front of the fuselage. The belt-type continuously variable transmission can be easily and easily supported on the fixed portion.

[0015]

According to the first aspect of the present invention, in the transmission structure of the riding type rice transplanter having the belt-type continuously variable transmission, both the first and second split pulleys are simultaneously moved and operated. With such a configuration, it is possible to avoid a state in which the movement of the pulley part on the other moving side is delayed with respect to the movement of the pulley part on the other moving side during shifting, and the transmission belt is slightly bent. As a result, the durability of the belt-type continuously variable transmission (particularly, the durability of the power transmission belt) can be improved.

According to the first aspect of the present invention, when a hydraulic pump is provided and a lubricating oil such as a transmission system is used as hydraulic oil, the hydraulic pump is disposed near a transmission case provided at a rear portion of the body. By doing so, the hydraulic oil supply system from the transmission case to the hydraulic pump can be shortened while avoiding the effects of engine vibration, heat, etc., so that the durability and structure of the hydraulic pump can be improved. In terms of simplification. Furthermore, since the hydraulic pump is close to the hydraulic mechanism provided at the rear of the fuselage, the hydraulic oil supply system from the hydraulic pump to the hydraulic mechanism can also be arranged short, simplifying the structure. This is even more advantageous in terms of realization, and by suppressing pressure loss, waste of power in the hydraulic pump can be suppressed.

When the belt-type continuously variable transmission and the hydraulic pump are arranged away from the engine at the front part of the body and near the transmission case provided at the rear part of the body, the belt-type continuously variable transmission and the hydraulic pump are characterized in that By arranging the hydraulic pump near the stepped transmission, it is possible to easily connect the input shaft of the belt-type continuously variable transmission to the hydraulic pump, which is further advantageous in terms of simplifying the structure. It became something. The hydraulic pump is driven at a substantially constant rotation speed regardless of the speed change in the belt-type continuously variable transmission, so that the supply of the hydraulic oil to the hydraulic mechanism is stably performed.

By providing a case for covering the belt-type continuously variable transmission, the adhesion of muddy water or the like to the belt-type continuously variable transmission can be prevented, and the belt-type continuously variable transmission can be prevented. Therefore, the durability of the belt-type continuously variable transmission can be further improved, and the comfort for the driver can be improved. In this case, the belt-type continuously variable transmission covered by the case as in the second aspect is separated from the engine at the front part of the body, and is connected to the transmission system near the transmission case provided at the rear part of the body. By arranging, the belt-type continuously variable transmission covered with the case can be easily and easily supported on the fixed portion, so that the support structure can be simplified and the reliability can be improved. Was. Also, even if the belt-type continuously variable transmission is arranged in a place where mud or the like on wheels is likely to adhere, such as near a transmission case that supports the rear axle, it is possible to prevent mud from adhering to the belt itself or the pulley,
Also in this regard, the durability of the belt-type continuously variable transmission can be further improved.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. 4 and 3 show a riding type rice transplanter, in which a seedling planting device 3 is provided at the rear of the body supported by front wheels 1 and rear wheels 2.
(Corresponding to a working device) is a link mechanism 4 and a hydraulic cylinder 5
Are connected so as to be able to move up and down freely. An engine 6 is arranged at the front of the body, and a bevel gear case 7, a transmission unit 8 and a transmission case 9 (corresponding to a transmission case) are arranged at the rear of the body. The power from the engine 6 is transmitted from the transmission shaft 10 to the rear wheel 2 via the bevel gear case 7, the transmission unit 8 and the transmission case 9, and from the transmission case 9 via the PTO shaft 29.
The power branched off immediately before the rear wheel 2 is transmitted to the front wheel 1 via the transmission shaft 11.

Next, the bevel gear case 7 will be described. As shown in FIG. 3, an input shaft 12 connected to a transmission shaft 10 from the engine 6 and an output shaft 13 oriented in the lateral direction of the machine are supported by the bevel gear case 7 and the input shaft 1
2 from the output shaft 1 via bevel gears 14 and 15
3 is transmitted. Hydraulic cylinder 5 and front wheel 1 shown in FIG.
A hydraulic pump 16 for a power steering mechanism (not shown) is connected to the right side of the body of the output shaft 13.
As shown in FIG. 3, the transmission unit 8 (the input shaft of a belt-type continuously variable transmission 18 described later) is connected to the output shaft 13 on the left side of the machine body. Mission case 9 as hydraulic oil
Is supplied from the hydraulic pump 16 to the hydraulic cylinder 5 and the power steering mechanism.

Next, the transmission unit 8 will be described.
As shown in FIGS. 1 and 2, the transmission unit 8 includes a pair of cases 17 and a belt-type continuously variable transmission 18 and a multi-plate-type main clutch 19 therein. The input shaft 20 and the output shaft 21 are supported by the case 17 and the input shaft 2
0, and a second pulley 23 externally fitted to the output shaft 21 so as to be relatively rotatable.
A transmission belt 24 is wound. As shown in FIG.
A tension pulley 25 of the transmission belt 24 and a spring 26 for urging the tension pulley 25 are provided.
With the above structure, the power from the output shaft 13 of the bevel gear case 7 is transmitted from the output shaft 21 to the transmission system of the transmission case 9 via the input shaft 20 and the main clutch 19 of the belt-type continuously variable transmission 18.

As shown in FIGS. 1 to 4, the transmission unit 8 moves the input shaft 20 to the front side of the vehicle so that the input shaft 20 and the output shaft 21 are located at substantially the same ground level.
The output shaft 21 is located on the rear side of the fuselage, and the case 17 that houses the first and second split pulleys 22 and 23 supported by these two shafts 20 and 21 is also arranged in a substantially horizontal posture. Have been. By arranging the case 17 in this manner, the lowest part can be grounded as much as possible as compared with the case where the case 17 is arranged vertically while being arranged at a lower position of the body corresponding to the lower side of the control section floor. It is positioned high so that the space on the fuselage side can be maintained high.

Next, the operation structure of the belt type continuously variable transmission 18 in the transmission unit 8 will be described. As shown in FIG. 1, in the first split pulley 22, a pulley portion on the left side of the drawing is fixed to the input shaft 20, and a pulley portion on the right side of the drawing is a pulley portion 22a on the moving side, and has a spline structure with respect to the input shaft 20. It is slidably supported. In the second split pulley 23, the pulley portion on the right side of the drawing is fixed to a collar 27 (relatively rotatable with respect to the output shaft 21), and the pulley portion on the left side of the drawing is a pulley portion 23a on the moving side, and It is slidably supported by a spline structure. As a result, as shown in FIG. 1, the pulley portion 22a on the moving side of the first split pulley 22 moves rightward in the drawing due to the tension of the transmission belt 24, and the pulley portion 23a on the moving side of the split pulley 23 moves leftward in the drawing. Energized to move.

As shown in FIGS. 1 and 2, first and second
A support shaft 28 is installed and fixed in parallel with the axial direction of the first and second split pulleys 22 and 23 over the right and left cases 17 so as to pass through the loop of the transmission belt 24 between the split pulleys 22 and 23. I have. A cylindrical operating shaft 30 is mounted on the support shaft 28.
(Equivalent to a speed change mechanism) is slidably fitted outside,
As shown in FIG. 1, a first operation arm 30a (corresponding to a speed change mechanism) is fixed to the right end of the operation shaft 30 in the drawing, and
The second operation arm 30b (corresponding to a speed change mechanism)
Has been fixed.

In both the pulley portions 22a and 23a on the moving side of both the first and second split pulleys 22 and 23, a bearing 36 is externally fitted to a portion opposite to the transmission belt 24, and an outer race of the bearing 36 is provided. The ends of the first and second operation arms 30a, 30b are in contact with the end of 36a. As shown in FIG. 1, the case 1
The operation arm 31 is swingably supported by the operation arm 7, and the tip of the operation arm 31 is engaged and connected to the operation shaft 30.

With the above structure, as shown in FIG. 1, the pulley portion 22a on the moving side of the first split pulley 22 is moved rightward in the drawing by the tension of the transmission belt 24 so that the second split pulley 2
Since the pulley portion 23a on the moving side of No. 3 is urged leftward in the drawing, the first operation arm 30a is urged rightward in the drawing, and the second operation arm 30b is urged leftward in the drawing. In this case, since the first and second operation arms 30a and 30b are fixed to the operation shaft 30, the first and second operation arms 30a and 30b do not move.

When the operating arm 31 is swung from the outside in the above state, the first and second operating arms 30a and 30b are operated.
Is slid integrally with the operation shaft 30 in the horizontal direction of the drawing of FIG. 1, and in conjunction with this, the first and second split pulleys 2 are moved.
Pulley portions 22a and 23a on both moving sides 2 and 23
Are slid in the same direction to change gears. FIG.
Is the lowest speed state in which both the pulley portions 22a and 23a on the moving side of both the first and second split pulleys 22 and 23 are slid to the rightmost on the sheet.

Next, the operation structure of the main clutch 19 in the transmission unit 8 will be described. As shown in FIG.
The main clutch 19 is urged to the on-operation side by a spring 19a, and the main arm 19 is disengaged by pushing the operation plate 19b leftward on the paper by the operation arm 34a. The operation arm 34a is the case 17 on the right side of the drawing.
The operation shaft 34 is fixed to the operation shaft 34
Project from the case 17 to the outer surface. A clutch pedal (not shown) provided on a control section of the fuselage and a protruding portion of the operation shaft 34 are mechanically interlocked by a link rod (not shown), and the clutch pedal is operated by depressing the clutch pedal. The main clutch 19 can be turned off.

[Alternative Embodiment] In the above-described embodiment, the cylindrical operating shaft 30 is externally slidably fitted to the fixed supporting shaft 28, but as shown in FIG. The support shaft 28 may be configured to be slid by an external bell crank 32 and an operation rod 33 by fixing the operation shaft 30 to the support shaft 28 and projecting the support shaft 28 from the case 17.

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 longitudinal sectional front view of a transmission unit.

FIG. 2 is a longitudinal sectional side view of a transmission unit.

FIG. 3 is a plan view schematically showing a transmission system in a riding rice transplanter.

FIG. 4 is an overall side view of a riding rice transplanter.

FIG. 5 is a longitudinal sectional front view of the vicinity of an operation shaft and first and second operation arms in another embodiment.

[Explanation of symbols]

Reference Signs List 3 Seedling plant 6 Engine 9 Transmission case 16 Hydraulic pump 17 Case 18 Belt-type continuously variable transmission 20 Input shaft of belt-type continuously variable transmission 22 First pulley 22a Pulley portion on the moving side of first split pulley 23 Second Split pulley 23a Pulley portion on the moving side of second split pulley 24 Power transmission belt 30, 30a, 30b Speed change operation mechanism

Claims (2)

(57) [Claims] [Claim 1 further comprising an engine (6) to the front of the fuselage, its
The output from the engine (6) is separated from the engine (6).
To the rear axle at the rear of the
A transmission structure of a riding type rice transplanter having a seedling planting device (3) at the rear, comprising a first pulley (22) and a second pulley (23) in which a pair of pulleys facing each other can freely move close to and away from each other. )
And a transmission belt (24) wound around the first and second split pulleys (22) and (23) to constitute a belt-type continuously variable transmission (18). The pulley portions (22a) and (23a) on both moving sides of the first and second split pulleys (22) and (23) are moved to the same low speed side and high speed side by operating the step transmission (18). Shift operation mechanism (30), (3
0a) and (30b), wherein the belt-type continuously variable transmission (18) is
A transmission mechanism for transmitting the power from (6) to the rear axle
When placed in the transmission system near the installed transmission case (9)
In both cases , a hydraulic pump (16) is arranged near the transmission case (9) and the belt type continuously variable transmission (18), and the input shaft (20) of the belt type continuously variable transmission (18) is connected to the hydraulic pump. (16) to connect the input shaft (2
The hydraulic pump (16) is configured to be driven by the power transmitted to the hydraulic pump (16), and the hydraulic pump (16) is configured to discharge using the lubricating oil of the transmission case (9) as hydraulic oil. A riding field
Transmission structure of planting machine. 2. The transmission structure of a riding type rice transplanter according to claim 1, further comprising a case (17) covering the belt type continuously variable transmission (18).