JPH0674335A - Belt type speed changer - Google Patents

Abstract

PURPOSE:To ensure a simultaneously operating condition and to suppress a speed change shock by using a fluid damper in a switching transmitter for push-pulling a tension arm in a tension giving means which can be high/low switched to be associated with an operating fixture of a rice planting machine or the like for riding. CONSTITUTION:In a rice planting machine or the like for riding, power of an engine is transmitted through a belt type speed changer, to drive front/rear wheels and also a planting device or the like. The belt type transmission is high/low switched by giving tension of tension springs 48, 49 of a tension giving means through tension arms 46, 47 individually relating to juxtaposed belts 43, 44, and the tension arms 46, 47 are operated by switching transmitters 52, 53 selectively operated through a switching member 51 associated with operating an operating fixture 35. Here are formed the switching transmitters 52, 53 into a damper constitution of fitting a piston into a cylinder of storing compression fluid, thus to attain shock reduction at the time of speed change operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt type transmission, and is used for a riding rice transplanter or the like.

[0002]

2. Description of the Related Art For example, there are a double tension type and a triple tension type as belt-type transmissions for passenger rice transplanters. The double-tension type transmission has two sets of pulleys on the engine side and the gear case side. This is a method of shifting gears and transmitting power by hanging a V-belt on a book and tensioning one of them with a tension pulley.

That is, as shown in FIG. 4, drive pulleys 2, 2 and a transmission input shaft 3 arranged in parallel with an engine output shaft 1.
The driven pulleys 4, 4 with different diameter
5 is wound around the belts 5, 5, and tensioning means 8 for individually applying tension of tension springs 6, 6 to the belts 5, 5 via tension arms 7, 7 is provided. And the tension arms 7, 7 are separately connected to each other, and a switching transmission body 10, 10 is provided, and an operation tool 11 engaged to switch the switching member 9 to swing is provided. Interlockingly, the tension arms 7,7 are pulled up against the tension springs 6,6 via the switching member 9 and the switching transmissions 10,10 to shift gears. In FIG. Only the high-speed side tension pulley 7A is pulled up by operating the tool 11). The tension pulley 7A on the low speed side uses the V-belt 5 by the tension spring 6.
Since it is acting in the direction of stretching, the low speed rotation is transmitted to the gear case side pulley 4. At high speed, the low speed side tension pulley 7A is pulled up, and the high speed side tension pulley 7A presses the V belt, so that high speed rotation is transmitted to the gear case side pulley 4.

Incidentally, in FIG. 4, reference numeral 12 is a clutch pedal, and when the pedal is depressed against a return spring (not shown), a connecting rod is provided.
The tension arms 7 and 7 are pulled up via 13 to cut off the power, which functions as a belt tension clutch.

[0005]

In the prior art shown in FIG. 4, the switching member 9 is swung about its fulcrum 9A by operating the operating tool 11 as shown by the arrow 14 about its fulcrum 11A. When being operated, one of the switching transmission bodies 10 pulls up the tension arm 7 against the tension spring 6 and the other switching transmission body 10 pulls down the tension arm 7 by the tension spring 6 to shift gears. There was a problem that shock was likely to occur and the operation force was large.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to make the switching transmission body for pushing and pulling the tension arm a fluid (gas, oil, etc.) damper so as to create a simultaneous operation state and suppress the shock of shifting. It is a thing.

[0007]

According to the present invention, drive pulleys 36 and 37 arranged in parallel with an engine output shaft 33 and a mission input shaft are provided.
The belts 43 and 44 are wound around the driven pulleys 41 and 42 having different diameters arranged in parallel with each other on the 38, and tensions of tension springs 48 and 49 are separately applied to the belts 43 and 44.
7 is provided with tension applying means 50, and a switching transmission member 52, 53 for separately connecting the switching member 51 capable of swing switching and the tension arms 46, 47, and swinging the switching member 51. With the operation tool 35 engaged to switch,
A belt-type transmission which is interlocked with the operation of the operation tool (35) to pull up the tension arms (46, 47) against the tension springs (48, 49) through the switching member (51) and the switching transmission bodies (52, 53) to shift gears. , In order to achieve the above-mentioned purpose, the following technical measures are taken.

That is, according to the present invention, the switching transmissions 52, 5 are
3 is the cylinder 55 and the piston rod inside this cylinder
A compressed fluid that includes a piston 57 that slides integrally with 56, and is capable of communicating with two chambers 58 and 59 defined by the piston 57.
It is characterized by containing 61.

[0009]

When the operating tool 35 is operated in the front-back direction about the fulcrum 45, the switching member 51 swings to push and pull the tension arms 46 and 47 through the switching transmission bodies 52 and 53 to shift gears.
Now, when the tension pulley 46A on the high speed side is off and the tension pulley 47A on the low speed side is on, the operation tool 35
When the switch transmission is switched to the high speed side, the high speed side switching transmission 52 remains in a state of being almost rigid without the damper being effective, while the switching transmission 53 in the low speed side tension pulley 47A acts as a damper and the piston rod 56 While stretching, the tension arm 47 is slowly pulled up against the tension spring 49, where a simultaneous operation state is secured and a shift shock is suppressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 3, a passenger rice transplanter 20 has an engine 22 mounted on the front side of its body 21. The power is transmitted to the mission in the mission case 23 via a belt type transmission 24 with double tension or triple pretension, drives the front wheels 25 and the rear wheels 26, and is attached to the rear part of the machine body 21 via an elevating link 27. It is adapted to drive the implanted device 28.

The engine 22 is covered with a hood 29, and a control device including a control handle 30 and a driver's seat 31 is provided on the body 21, and a transmission 24 is operated on one side of the control handle 30. Sub shift lever (operation tool) 32
However, a main gear shift lever (not shown) is provided on the other side.
Referring to FIGS. 1 and 2, the transmission 24 and its operating means are illustrated as a double tension, and a high / low speed drive pulley 36 is mounted on an engine output shaft 33 via a key 34 and a stopper 35 such as a bolt. , 37 are arranged in parallel, and driven pulleys 41,42 with different diameters are arranged in parallel on the mission input shaft 38 via a pulley boss 39, a stopper 40, etc. V belt 43,44 over driven pulleys 41,42
Is wrapped around.

A fulcrum shaft is attached to the side wall boss of the mission case 23.
45 is screwed and fixed, and the fulcrum shaft 45 rotatably supports the boss portions of the high / low speed tension arms 46 and 47 and rotatably supports the lower portion of the operation tool 32.
A belt is attached to the tip of the high and low speed tension arms 46 and 47.
Tension pulley 46A that can be moved in and out of 43, 44
47A, tension springs 48, 49 are attached to the pin at the rear end and the bracket on the fixed side, and the tension applying means 50 is provided.
It is said that.

A switching member 51 with which an engaging pin 32A provided in the middle of the operating tool 32 engages through a long hole 51A is provided so as to be swingable about a fulcrum shaft 51B. Switch gears 52, 5 are installed between the front and rear and in the middle of tension arms 46, 47.
3 is connected to one of the tension arms 48, 49 against the one tension spring 48, 49 by the operation in the direction 54 shown in FIG. 1 (A) centering on the fulcrum shaft 45 of the operation tool 32. Four
6, 47 are pulled up, and the other tension arms 46, 37 can apply the tension of the other tension springs 48, 49 to the belt.

The switching transmissions 52, 53 are gas springs (fluid dampers) as shown in FIG. 1 (B), and are provided with a cylinder 55 and a piston 57 which slides integrally with the piston rod 56 inside the cylinder 55. , 2 divided by the piston 57
Compressed fluid 61 that allows chambers 58 and 59 to communicate with each other through small holes 60, etc.
Is enclosed. Here, the pressure of the compressed fluid (gas, oil) 61 is used as a spring to function as a damper.

Therefore, when the low speed side of FIG. 1 (A) is turned on and the speed is switched to the high speed, the operating member 35 is operated as shown by an arrow 54, and the switching member 51 swings back and forth. Switch transmission 52 pushes down tension arm 46 and tension spring 48
By this action, the slack side of the belt 43 is rigidly pressed against the pulley 46A, while the low speed side tension arm 47 is pulled up against the tension spring 49 via the switching transmission body 53.
At this time, the switching transmission 53 is slowly pulled up by the damper action as the piston rod 56 extends and the fluid flows through the two chambers 58 and 59, and the low-speed tension is cut off until the high-speed tension is turned on. Instead, the shift shock is reduced and high-low speed switching is performed.

Further, in FIG. 1 (A), a main clutch pedal 62 is provided so as to be freely stepped against a return spring, and the pedal arm 62A and the tension arms 46, 47 are connected by a clutch rod 63 having a play 63A. ing. Then, the damper action is not exerted in the pedal disengagement direction (arrow a in FIG. 1A) with respect to the pedal arm 62A, and the pedal disengagement direction (FIG.
(A) arrow b), that is, a damper 64 that exhibits a damper action in the pedal return direction is provided.
The configuration of 64 is substantially the same as that of FIG.

In the embodiment, the cylinder 55 of the switching transmissions 52 and 53 is used as the switching member 51, and the rod 56 is used as the tension arm.
Although linked to 46,47, this may be reversed.

[0018]

The present invention is as described above, and the switching transmission for pushing and pulling the tension arm that is switched between high and low in conjunction with the operation tool is a fluid damper.
The simultaneous operation state is secured, and the shift shock can be reduced.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention, (A) is a side view,
(B) is a cross-sectional view of a switching transmission body (damper).

FIG. 2 is an exploded perspective view showing an embodiment of the present invention.

FIG. 3 is a side view of a rice transplanter to which the present invention is applied.

FIG. 4 is a side view of a conventional example.

[Explanation of symbols]

 33 Engine Output Shaft 35 Operation Tool 36 Drive Pulley 37 Drive Pulley 38 Mission Input Shaft 41 Driven Pulley 42 Driven Pulley 43 Belt 44 Belt 46 Tension Arm 47 Tension Arm 48 Tension Spring 49 Tension Spring 51 Switching Member 52 Switching Transmission Body 53 Switching Transmission Body 55 Cylinder 56 Piston rod 57 Piston 58 Chamber 59 Chamber

Claims (1)

[Claims] 1. A drive pulley (36), (37) arranged in parallel with an engine output shaft (33) and a driven pulley (41), (42) arranged in parallel with a mission input shaft (38) and having different diameters. Belt (43), (44)
The tension of the tension springs (48) and (49) is separately applied to the belts (43) and (44).
6), (47) is provided with the tension applying means (50), and the swing transmission freely switching member (51) and the tension arm (46), (47) is connected to the switching transmission body separately (52), (53)
And an operating tool (35) engaged to swing and switch the switching member (51). The switching member (51) and the switching transmission body are linked to the operation of the operating tool (35). A belt type transmission for pulling up tension arms (46), (47) against tension springs (48), (49) via (52), (53) to shift gears. 52) and (53) are provided with a cylinder (55) and a piston (57) that slides integrally with the piston rod (56) inside the cylinder, and two chambers (5) partitioned by the piston (57).
A belt type transmission characterized in that a compressed fluid (61) which can communicate with each other is enclosed in 8) and (59).