JP2617364B2 - Belt transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt transmission device mainly mounted on a power agricultural machine such as a rice transplanter.

2. Description of the Related Art Powered agricultural machines such as rice transplanters, agricultural tractors, and combine harvesters are designed to reduce the vibration received from the engine as much as possible to improve maneuverability. Many types of anti-vibration types are used, in which vibration is supported via members, and a power transmission between an engine and a transmission case is generally performed by a belt transmission using a V pulley and a transmission belt (V belt). I have. And, the intermittent power of the transmission belt that is stretched between the driving pulley (engine pulley) and the driven pulley (transmission input pulley) of the belt transmission device is usually
Operating arm (tension clutch arm) linked to operating tools such as operating levers and clutch pedals via rods
The rotation operation is performed.

SUMMARY OF THE INVENTION However, when the belt drive is a vibration damping type of engine as above, the tensile direction is absolutely engine because the engine pulley force acts about to be pulled in the belt tension direction by the tension of the belt When the engine is tilted, a belt slip occurs and not only the transmission capacity is reduced, but also a problem such as a clutch disconnection failure occurs. In general, engine pulleys are generally equipped with a multi-stage transmission mechanism with multiple transmission belts between the engine pulley and the transmission input pulley, or with a structure in which the power of the hydraulic mechanism is taken directly from the engine pulley by belt transmission. Since it is a multiple pulley with a large amount of overhang from the engine, the adverse effect of belt tension cannot be ignored.

Means for Solving the Problems Accordingly, the present invention provides an anti-vibration support for an engine via an elastic member such as rubber or a leaf spring, and an operation arm for controlling the intermittent power by the belt transmission from the engine via a rod. In the actuator connected to the operating tool, the operating arm is rotatably supported on the engine side, and the force applied by the rod to the engine and the force applied by the transmission belt to the engine when the power of the transmission belt is transmitted to the rod are offset. It is an object of the present invention to solve the above-mentioned problem by providing a rod at an attachment angle that is set.

The engine pulls in the direction of the belt tension due to the belt tension during belt transmission, and the engine tends to tilt in the belt tension direction, but the operating arm is rotatably supported by the engine. Also, a rod is provided at a mounting angle at which a force applied to the engine by the rod and a force applied to the engine by the transmission belt are offset when the power connecting the rod connecting the operating arm and the operating tool to the transmission belt is transmitted. As a result, the rod exerts a force that pushes the engine back in a direction opposite to the belt tension of the force applied by the transmission belt to the engine, thereby preventing the engine from tilting or twisting due to the belt tension.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described with reference to an embodiment shown in the drawings. In the drawings, a vehicle body 3 having a front wheel 1 and a rear wheel 2 is lifted and lowered behind a main body 5 having an engine 4 mounted on a front portion thereof. A riding rice transplanter equipped with a planting section 7 via a link mechanism 6 is illustrated.

Reference numeral 8 denotes a driver's seat, 9 denotes a steering handle, 10 denotes a driving operation panel, 11 denotes a hood formed by integrally extending and fixing a step 12 on both the left and right sides, and the bonnet 11 has a rotation fulcrum 13 provided at a front end. It is configured so as to rotate forward to a substantially fully opened state together with the step 12 around the center, so that maintenance around the engine can be improved.

14 is the rear cover of the bonnet 11, 15 is the main shift lever,
16 is a fuel tank, 17 is a sub-transmission lever (operating tool), 18 is a clutch pedal (operating tool), 19 is a front axle, 20 is a rear axle, 21 is a driveshaft, 22 is a bumper, 23 is a balance weight, M Is the mission case, S
Is a driver's seat step.

The transmission case M supports the front wheels 1 and is disposed on the front side of the body frame 3a at a position below and forward of the driver's seat step S as shown in the figure. 4 front, back, left and right
It is fixed to an engine base 25 supported via elastic members 24 such as rubber and leaf springs with bolts 24a and nuts 24b. Reference numeral 26 denotes a four-unit engine pulley (drive pulley), 27 denotes a transmission main shaft pulley (driven pulley) provided below the drive pulley 26, and in the illustrated example, three transmission belts 28 and 29 are provided between the pulleys 26 and 27. , 30 are wound side by side with different transmission ratios, and a three-speed sub-shift in which the speed is switched among low, middle, and high speeds by the sub-shift lever 17 in the hood rear cover 18. Apparatus D is provided. The innermost portion of the engine pulley 26 and the input pulley of a hydraulic pump (not shown)
A hydraulic belt 32 is wound between 31 and the hydraulic belt 32
The power is constantly transmitted to the hydraulic pump that controls the elevating and lowering of the planting part by the use of 32. 33 is a tight pulley of the hydraulic belt 32. 34, 34a and 34b are substantially arc-shaped operating arms which are independently and rotatably supported on single support shafts 36 projecting from a base 35 fixed to the side wall of the engine 4 on the base end side. In the (clutch arm), the base ends of the operating arms 34, 34a, 34b are adjustable rods 37, 3
Tight pulleys P are pivotally supported at the ends of the arms, respectively, and are connected to the auxiliary transmission lever 17 via 7a, 37b and the like, and these constitute an auxiliary transmission D. In more detail, the operating arms 34, 34a, 3
A plurality of cams 38, 38a, 38b corresponding to 4b are integrally formed side by side to form a substantially fan-shaped operating portion 39, and the sub-transmission lever 17 and the operating portion 39 are fixed to the steering column 40. The cams 38, 38a, 38b are mounted on the support shaft 42 projecting from the upper part of the bracket 41 so as to be tiltable in the front-rear direction, and the transmission driving recesses 38 ', 38'a, 38'b are respectively provided on the outer periphery of the cams 38, 38a, 38b in the front-rear direction. It is provided with a bias. That is, the front cam 38 has a high-speed recess on the rear side.
38 ′, and a middle speed recess 3 in the middle cam 38a.
8 ′, and a concave portion 38′b for low speed
On the other hand, driven shafts 44, 44a, 44b each having a rotator b abutting on the outer peripheral edge of the cams 38, 38a, 38b are mounted on a support shaft 43 protruding from the lower portion of the bracket 41 by an elastic machine c. The child b is always rotatably supported while being pressed against the outer periphery of the cam 38, 38a, 38b, and the driven cams 44, 44a, 44b are
It is connected to 7,37a and 37b respectively.

Each of the operating arms 34, 34a, 34b drives the corresponding transmission belt (clutch-in) when the trochanter b is fitted into the corresponding recess 38 ', 38'a, 38'b of the corresponding cam 38, 38a, 38b. And the non-drive (clutch disengaged) state is maintained at any other position.
The operation arm is switched to the "off" state via a plate 46 fixed to the support shaft 45 and the support shaft 43.
In order to operate only the operation arm in the “in” state, the rod mounting portion of the plate 46 is provided with a flexible mechanism 47 including a pin 46a and a long hole 46b. This eliminates the need for a troublesome pedal operation by separately providing an all-stop device using a clutch pedal as in the prior art, thereby improving operability.

A relatively shallow concave portion 48 for positioning the neutral position is provided at the front end of the front side cam 38, and the shift position of the auxiliary transmission lever 17 is from the rear to the front, the high-speed position H, the medium-speed position M, The linear shift pattern has a low speed position L and a neutral position N. In the figure, 49 and 50 are adjustment bolts for position adjustment, and 51 is a guide groove of the auxiliary transmission lever 17.

By the way, the operating arms 34, 34a, 34b and the rods 37, 3
7a and 37b are provided so as to bypass the outer periphery of the driving pulley 26 as shown in the figure, and the rods 37, 37a and 37b are located on the tension side of the transmission belts 28, 29 and 30 to reduce the belt tension. It is provided to oppose. Here, the opposition to the belt tension means that the mounting angle of the rods 37, 37a, 37b with respect to the power transmission belts 28, 29, 30 is determined when the power transmission of the power transmission belts 28, 29, 30 occurs.
The rods 37, 37a, 37b are capable of opposing the belt tension (F in FIG. 10) of the force applied to the engine 4 by the rods 8, 29, 30. That is, the rods 37, 37a, 37b project against the belt tension. It means that the angle is set so that it can function as a stick. Therefore, it is ideal that the rod is set substantially parallel to the direction of the belt tension F, but it is not necessary that the rod be parallel. In practice, however it is desirable 45 ⁰ within during power transmission.

By the way, the belt guide 52
Are provided integrally, and fixed belt retainers 54 and 55 are provided on both front and rear sides (the loose side and the tight side of the belt) of the transmission belt. That is, the stays 56, 57 are fixed to the engine side via cantilever bolts 58, 59 in a cantilevered state and the mounting angle can be freely adjusted, and stepped bar-shaped belt pressers 54, 55 are provided at the lower end sides of the front and rear stays 56, 57. A drive pulley 2 is provided on the lower side of the outward bent portion 57a formed on the upper end of the inclined portion of the rear stay 57.
A stepped bell holder 60 corresponding to the shape of 6 is formed, and a substantially semi-arc belt
Is fixed to the transmission case M via the bracket 61a and the bolt 61b, and the belt guide 52, the belt retainers 54, 55,
The transmission belts 60, 61 allow the transmission belts 28, 29, 30 to be pressed from the outside at key points when the clutch is disengaged, so that a belt guide effect can be obtained over substantially the entire circumference.

In addition, one or a plurality of holes 62 for draining muddy water are provided on the bottom surface of the substantially semi-arc-shaped belt presser 61, and muddy water that has entered the belt presser 61 due to splashing of muddy water during car washing or during work. Hole 62
From the machine to prevent belt slip and damage to the belt and pulley. Further, an opening / closing lid 64 for covering the belt retainer 61 and the side opening 63 is formed separately from the belt retainer 61, and is detachable via a bracket 65 fixed to the belt retainer 61 and mounting bolts (not shown). The belt presser 61 and the opening / closing lid 64 cover the entire driven pulley 27. In the figure, reference numeral 65 denotes an oil drain gutter.

In this embodiment, the vertical belt transmission used in the sub-transmission with three-speed transmission has been described. However, the present invention is widely applied to transmissions other than the sub-transmission as long as the transmission is based on belt transmission. It can also be used for horizontal belt transmissions, and also for devices other than power farming machines such as rice transplanters.

In the above configuration, when the sub-transmission lever 17 is at the middle speed position M as shown by the solid line in FIG. 8, the trochanter b provided on the plate 44a on the side of the central operating arm 34a is connected to the corresponding cam 38a. And only the center plate 44a is displaced upward about the support shaft 43, so that the rod 37a connected to the center plate 44a is pushed forward and Working arm 34a on the side is a spindle
It rotates counterclockwise in FIG. 4 around 36 to tension the middle speed belt 29. In this case the other working arm 3
The plates 44, 44b linked to 4, 34b are the corresponding cams 3
Since the trochanter b is pressed downward against the elastic machine c at the outer peripheral edge of 8, 38b, the trochanter b is held in a non-driven state. Next, when the sub-transmission lever 17 is operated to the high-speed position H, the operating portion 39 is
To the front, and this time the front side operating arm 34
Is inserted into the concave portion 38 'of the cam 38,
Presses the transmission belt 28 on the high-speed side to be driven. At this time, the other operating arms 34a and 34b are kept in the non-driven state in the same manner as described above. Similarly, at the low speed position L, the rotator b on the side of the rear operation arm 34b is fitted into the concave portion 38'b of the cam 38b, and the operation arm 34b presses the transmission belt 30 on the low speed side to be driven. When the sub-transmission lever 17 is tilted to the foremost position, the rotator b on the side of the front operation arm 34 is fitted into the neutral recess 48 of the cam 38 so that the operation portion 39 and the sub-transmission lever 17 are positioned at the neutral position H. Therefore, power transmission from the engine 4 to the transmission case M is completely shut off.

By the way, at the time of belt transmission, a force for lowering the engine pulley 26 in the direction of the belt tension F is applied to the engine pulley 26 by the belt tension F, so that the engine 4 supported by vibration isolation via the elastic member 24 is pulled in the direction of the belt tension F. The operating arms 34, 34, 34b are rotatably supported on the engine 4 side, and a rod 37 connecting the operating arms 34, 34, 34b and the sub-transmission lever 17 is inclined. , 37a, 37b are provided to oppose the belt tension F of the force applied to the engine 4 by the power transmission belts 28, 29, 30 when the power transmission belts 28, 29, 30 transmit power. There exerts a force F ₁ to push up so the engine 4 in the direction opposite the belt tension F. For this reason, the rods 37, 37a, and 37b perform the function of the rods for the engine 4, so that the tilting of the engine 4 due to the belt tension F is effectively prevented. As a result, occurrence of belt slip due to the inclination or twist of the engine 4 and reduction in transmission capacity due to the belt slip and poor clutch disconnection are prevented. In the horizontal belt transmission, the same effect as described above can be obtained because the engine is prevented from being twisted due to belt tension.

Advantageous Effects of the Invention As described above, the present invention provides a vibration-damping support for an engine via an elastic member such as rubber or a leaf spring, and an operating tool via a rod for an operation arm for controlling the intermittent power transmission by the belt transmission from the engine. In the above-mentioned structure, the operating arm is rotatably supported on the engine side, and when the power of the power transmission belt is transmitted to the rod, the force applied by the rod to the engine and the power applied by the power transmission belt to the engine are offset. Since the rod is provided at the mounting angle, the rod at the time of power transmission functions as a strut bar that opposes the belt tension of the force applied to the engine by the power transmission belt, so that tilting and twisting of the engine due to the belt tension are prevented. Do not use special members to prevent the occurrence of belt slip due to the inclination of the engine, the reduction in transmission capacity due to the belt slip, and the poor clutch disconnection. It can be solved all at once.

[Brief description of the drawings]

1 is an overall side view of a riding rice transplanter equipped with the present invention, FIG. 2 is a plan view of an engine mounting portion, FIG. 3 is a side view showing a mounting structure of an engine and a transmission case, and FIG. , FIG. 5 is a front view of a belt transmission in a subtransmission, FIG. 6 is a plan view of a main portion, FIG. 7 is a rear view of a transmission operation portion, and FIG. 8 is a transmission pattern of a subtransmission lever. 9 (A) is a side view showing a cam shape of an operating portion, FIG. 9 (B) is a perspective view of a belt retainer on a transmission main shaft pulley side and an opening / closing cover thereof, and FIG. FIG. 11 is an explanatory view of the operation of the main part when the clutch is disengaged, FIG. 11 is an explanatory view of the operation of the main part when the clutch is disengaged, and FIG. 12 is a perspective view of the belt presser on the belt tension side. 4 Engine, 17 Operating device (sub-shift lever), 18
... operating tool (clutch pedal), 22 ... clutch pedal,
24 ... elastic member, 26 ... engine pulley (drive pulley), 27 ... transmission main shaft pulley (driven pulley), 2
8, 29, 30… Power transmission belt, 34, 34a, 34b… Actuating arm, 3
7, 37a, 37b: rod, 45: rod, D: auxiliary transmission.

Claims (1)

(57) [Claims] 1. An engine in which an engine is supported by vibration isolation through an elastic member such as rubber or a leaf spring, and an operation arm that controls the intermittent power by belt transmission from the engine is connected to an operating tool through a rod. The operating arm is rotatably supported on the engine side, and the rod is attached at an installation angle at which the force applied to the engine by the rod and the force applied to the engine by the transmission belt are offset when the power is transmitted from the transmission belt. A belt transmission device provided.