JPH0331123Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a safety device for the planting section of a rice transplanter that automatically cuts off power transmission to the planting section when an abnormal load is applied to the planting section. It is something.

(Prior art and problems) Conventionally, as shown in Fig. 4, an inter-plant transmission system has been used, which consists of a combination of a plurality of transmission gears N, N', ... in the power transmission path C from engine A to planting part B. In a rice transplanter that is equipped with a mechanism (E) and is configured to change between planted plants by switching the transmission gear, a torque clutch is separately installed on the outside of the inter-plant transmission mechanism (E) as a safety device in the event of an abnormal load in the planting section (B). This increased costs and complicated the structure, making it difficult to make the machine compact.

(Means for Solving the Problems) Therefore, the present invention makes it possible to switch the engagement of multiple transmission gears in the power transmission line from the engine to the planting section through a switching operation unit consisting of a shift shaft, etc. In a rice transplanter configured to change the distance between planted plants in a planting section by providing a variable speed mechanism between plants,
It is configured such that a thrust load is applied to the meshing of the transmission gear, and when an abnormal load is applied to the planting section, the transmission gear is disengaged and the inter-plant transmission mechanism becomes a neutral state, and the switching operation section changes gears. By configuring the gear to maintain a neutral state, the above-mentioned drawbacks of the prior art are attempted to be overcome.

(Embodiment) To explain the configuration of the present invention with reference to an embodiment shown in the drawings, FIG. 3 shows a walk-behind rice transplanter, which has swing wheels 1, 1 on both left and right sides in the direction of movement. The engine 3 is located at the front of the traveling aircraft 2.
The rear part is equipped with a planting section A consisting of a seedling stand 4 that reciprocates left and right, a planting claw 5, a drive case 6, etc. Below the fuselage 2 is a float 7 for sliding on the rice field. is arranged, and the power of the engine 2 is transmitted to the swing wheels 1, 1 of the traveling section via a power transmission path consisting of a group of gears etc. in the transmission case 8, and is also transmitted to the planting section A. As a result, the planting claws 5 move up and down while traveling on the rice field, and sequentially scrape off the pine seedlings on the seedling stand 4 one by one, leaving a predetermined space between the planted plants on the rice field. They are now being planted continuously. An inter-plant transmission mechanism B consisting of a combination of a plurality of transmission gears is provided in the power transmission line 3a leading from the engine 3 to the planting section A, and the transmission between the planted plants is changed by changing the transmission gears as necessary. It is now possible to change. Figure 1 shows the above-mentioned inter-stock transmission mechanism B.
The internal structure diagram of mission case 8 incorporating
9 is a main shaft, 10 and 11 are intermediate shafts, and 12 is a drive shaft for the swing wheels 1, 1. A drive-side transmission gear 13 of the inter-stock transmission mechanism B is slidably spline-engaged with the main shaft 9 only in the axial direction, and a driven-side transmission gear 14 with which the drive-side transmission gear 13 selectively meshes. 15 are each fixed to the intermediate shaft 10 in a spaced state. A sprocket 16 is located on one side of the transmission gears 14 and 15 and is located on the intermediate shaft 10.
is fixed, and a transmission chain 1 is connected between this sprocket 16 and the input sprocket 17 of the planting part A.
8 is suspended. In FIG. 2, D is a switching operation section for switching the engagement between the drive side change gear 13 and the driven side change gears 14 and 15. That is,
By pushing and pulling the shift shaft 19, the drive-side transmission gear 13 slides on the main shaft 9 and selectively meshes with the driven-side transmission gears 14, 15. ) can be performed arbitrarily. The shift shaft 19 and the drive-side transmission gear 13 are positioned by steel balls 20 at a high speed position (narrow space between plants) or a low speed position (wide space between plants). 21 is a steel ball pressing spring, and 22 is a spring holding bolt.

By the way, the safety device C is configured so that a thrust load is applied to the engagement between the driven side speed change gear 14 or 15 and the driving side speed change gear 13. For example, the above-mentioned transmission gears 13, 14, and 15 may be formed into helical gears, chamfers (tooth chamfers) may be applied to make the chamfers wrap during meshing, or tooth lines may be tapered, or the gears may be tilted in the direction in which the gears come out. Although various methods such as the above are possible, the illustrated example is one in which a chamfer a is applied. When an abnormal load is applied to the planting part A, a thrust load acts on the meshing of the transmission gears 13, 14 or 13, 15, and this causes the drive side transmission gear 13 to move in the direction of the arrow in FIG. It is adapted to be moved and positioned at a neutral position. Therefore, the spring pressure of the steel ball pressing spring 21 is set to a predetermined spring pressure. 23 and 24 are steel ball fitting grooves for positioning provided on the shift shaft 19, and the shaft portion between the left and right steel ball fitting grooves 23 and 24 is the steel ball 20.
It serves as a neutral position holding part N for. 2 in the diagram
5 is a fuselage frame, and 26 is a steering handle.

(Function) In the configuration as described above, the power of the engine 3 is transmitted to the drive side transmission gear 13 via the main shaft 9,
The driven side transmission gear 1 meshing with the transmission gear 13
4 or 15 to the intermediate shaft 10, and is further transmitted to the planting section A by the sprockets 16, 17 and the transmission chain 18, and the planting claws 5, seedling stand 4, etc. are driven to perform the planting work. . By the way, the gears 13, 14 or 13, 15 are in mesh during the planting work.
Since the thrust load applied to the transmission gear is received by the steel balls 20, the transmission gear 13 on the drive side does not slide in the axial direction.
5 does not disengage, and power transmission from the engine 3 to the planting section A is maintained, but when an abnormal load is applied to the planting section A, the thrust load acting on the transmission gear 13 increases. The spring pressure of the steel ball pressing spring 21 is lost, and as a result, the shift shaft 19 and the drive-side transmission gear 13 slide and disengage, and the inter-stock transmission mechanism B enters the neutral state, and the shift shaft 19 and the transmission gear 13 are disengaged. Since the neutral position holding portion N of the shift shaft 19 moves integrally with the steel ball 20 against the steel ball pressing spring 21, the thrust load is received by the steel ball 20. The neutral state of the inter-stock transmission mechanism B is maintained by the spring pressure of the steel ball pressing spring 21.
As a result, the transmission of power to the planting section A is cut off, thereby preventing damage to the planting section A due to abnormal loads.

In this way, the safety device C against abnormal loads in the planting section A is integrally incorporated into the inter-plant transmission mechanism B, and in particular, in this embodiment, the transmission gears 13, 1
Since the chamfer a is applied to the 4 and 15 themselves, there is no need to separately provide a torque clutch unlike the conventional ones, and it is therefore possible to make the machine lighter, cheaper and more compact.
Furthermore, when the transmission gears 13, 14, and 15 act as torque limiters, they are completely disengaged, so they do not generate unpleasant rattling noises like conventional torque limiters, which is extremely convenient.

(Effects) As described above, the present invention provides an inter-plant transmission system in which the meshing of a plurality of transmission gears in the power transmission path from the engine to the planting section can be switched via a switching operation section consisting of a shift shaft, etc. In a rice transplanter configured to provide a mechanism to change the distance between planted plants in the planting section, the mechanism is configured so that a thrust load is applied to the meshing of the transmission gear, and when an abnormal load is applied to the planting section, the transmission Since the gears are disengaged and the interplant transmission mechanism becomes neutral, the switching operation section maintains the transmission gear in the neutral state, so a torque clutch like the conventional one can be used as a safety device for the planting section. There is no need to provide any separate equipment, making it possible to provide a lightweight, inexpensive, and even more compact rice transplanter.In addition, when the transmission gear of the inter-plant transmission mechanism comes off and acts as a torque limiter,
To reliably eliminate the occurrence of an abnormal rattling noise (unpleasant noise) associated with a conventional torque limiter, since the transmission gear is completely disengaged and the interstitial transmission mechanism becomes a neutral state, and the neutral state can be maintained. I can do it. Furthermore, the present invention can be widely applied as a safety device not only for rice transplanters but also for power agricultural machinery in general.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts, FIG. 2 is an explanatory diagram of the operation of the main parts, FIG. 3 is an overall side view of a rice transplanter equipped with the present invention, and FIG. 4 is a sectional view of a conventional example. In the figure, 3 is the engine, 3a is the power transmission line, 1
3, 14, and 15 are transmission gears, 19 is a shift shaft, A is a planting section, B is an interplant transmission mechanism, C is a safety device, and D is a switching operation section.

Claims (1)

[Scope of utility model registration request] A plant-to-plant transmission mechanism is provided in the power transmission path from the engine to the planting section, in which the meshing of a plurality of transmission gears can be switched via a switching operation section consisting of a shift shaft, etc. The rice transplanter is configured so that a thrust load is applied to the meshing of the transmission gear, and when an abnormal load is applied to the planting section, the transmission gear is disengaged and the inter-plant transmission mechanism is in a neutral state. A safety device for a planting section of a rice transplanter, characterized in that the switching operation section is configured to maintain a neutral state of the transmission gear.