JP4720113B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle for agriculture, construction, transportation, or garden management.

Conventionally, when a cruise control device is mounted on a working vehicle such as a riding lawn mower, a shift pedal or a shift lever (cruise control lever) is rotatably supported and a friction material is provided at the rotation base. The position is maintained. For example, in Japanese Patent Application Laid-Open No. 7-46924, a friction holding type cruise control lever is provided, and the operation position of the lever is held in preference to the holding position of the shift pedal, and the speed change operation shaft of the hydrostatic continuously variable transmission is provided. The rotation position is held.
Japanese Unexamined Patent Publication No. 7-46924

However, as described above, the configuration in which the friction material is provided in the rotation base of the shift pedal or the shift lever applies a braking force to the shift pedal or the shift lever even during a normal shift operation, and requires a large operating force in the dark. There was a problem that quick shifting operation could not be performed and that it was difficult to perform fine speed adjustment.

In addition, the shift pedal of the work vehicle equipped with these cruise control devices, or the base of the shift lever is provided with a neutral return mechanism, various link mechanisms, hydraulic equipment, etc., especially in the case of a small vehicle. However, there was also a problem that the maintenance was narrow and time-consuming. Then, the neutral return of the speed change operation shaft is performed gradually. Further, it is possible to cope with a specification that does not require a cruise control device, that is, a brake mechanism that holds the rotation position of the shift pedal.

This application is configured as follows in order to solve the above-described problems.

That is, the invention described in claim 1 is equipped with a continuously variable transmission (1), and is switched between forward and backward movements and step-up / deceleration shifts by depressing a shift pedal (3, 4) in the vicinity of the cockpit (S). The shift pedal (3, 4) is supported by a support shaft (5) projecting from the side of the vehicle body, and the pedal (3, 4) base and the same side of the vehicle body The speed change operation shaft (7) of the continuously variable transmission (1) projecting from the shaft is operated to rotate the speed change operation shaft (7) by depressing the pedal (3, 4) via the link mechanism (6). A support shaft (5) integrally connected to the pedal base is extended to the other side of the vehicle body and protruded, and the rotation position of the support shaft (5) is held at this end. A brake mechanism (11) is provided, and the speed change operation shaft (7) and the trunnion arm (22) are connected, The neutral cam arm (30a) is supported behind the holding shaft (5), and the trunnion arm (22) is always returned to the neutral position via the neutral cam arm (30a) by the spring (30b). The brake mechanism (11) that holds the rotational position of (5) is rotated integrally with the coaxial (5) and the brake arm (11a, 11a) that is expanded around the coaxial (5) and supported on the vehicle body side. And an inner expansion brake including a plurality of bosses on the side of the HST cover (8) in which the continuously variable transmission (1) is built. (10, 10...) Projecting so as to be attachable to the side, and the brake case (11 c) is detachably attached to the ends of the plurality of bosses (10, 10...) Via plates. HS A damper (19) is provided in the gap between the cover (8) and the brake case (11c) to gently bias the support shaft (5) to the neutral position against the bias of the neutral cam arm (30a). Further, the brake mechanism (11) is turned on and off by an operating tool (15) provided on the fender (17) in the vicinity of the cockpit (S), and is provided on the speed change pedal (3, 4) side so that the vehicle travels. depresses the brake pedal (12) for braking result in and a working vehicle, characterized in that the operating member (15) is operated and configured to release the auto-cruise filled state.
(Operation of claim 1)
The work vehicle according to claim 1 configured as described above has a speed change operation shaft (7) of the continuously variable transmission (1) via the movement of the link mechanism (6) when the speed change pedal (3, 4) is depressed. Is rotated to change the vehicle speed. The support shaft (5) integrally formed with the pedal base is extended to the other side of the vehicle body, and the support shaft (5), that is, the stepping position of the speed change pedal (3, 4) is extended by the brake mechanism (11) on the other side. Is retained.
The neutral cam arm (30a) is supported behind the support shaft (5), and the trunnion arm (22) is always returned to the neutral position via the neutral cam arm (30a) by the spring (30b). The speed change operation shaft (7) connected to the trunnion arm (22) also returns to the neutral position. The brake case (11c) of the inward expansion brake is made detachable.
When the operation tool (15) in the vicinity of the cockpit (S) is operated, the inward-expanding brake is activated, the braking action is exerted on the support shaft (5), and the depression position of the shift pedal (3, 4) is changed. Retained.
Further, the damper (19) gently biases the support shaft (5), that is, the speed change pedal (3, 4) to the neutral position against the bias of the neutral cam arm (30a).
The brake mechanism (11) is turned on and off by an operating tool (15) provided on the fender (17) in the vicinity of the cockpit (S). Depresses the brake pedal for braking the vehicle traveling is provided to the shift pedal (3, 4) side (12), the said operating member (15) releases the which the auto cruise filled state is operated.

The invention according to claim 2 is characterized in that the rotation base of the neutral cam arm (30a) is connected to the throttle mechanism (31) of the engine (E) via a wire (7b). The work vehicle described in 1 was used.
(Operation of claim 2)
In the work vehicle according to claim 1 configured as described above, the engine (E) is also accelerated by operating the shift pedal (3, 4).

As a result, the invention described in claim 1 is equipped with a link mechanism (6) leading to a continuously variable transmission on one side of the vehicle body and a brake mechanism (11) on the other side as compared with this type of conventional device. Therefore, there is an advantage that the space on both sides can be used effectively and there is a margin in the surroundings, so that adjustments such as maintenance can be easily performed.
By turning on and off the operating tool (15) in the vicinity of the cockpit (S), the inner expansion brake is switched between an operating state and a non-operating state. In particular, in the non-operating state, the brake acts on the support shaft (5). Therefore, the operating force is light and the operability is good as compared with the conventional configuration in which a friction material is provided at the base of the shift pedal and the braking force is always applied.
In addition, the brake mechanism (11) that extends from the inner side is configured such that a plurality of bosses (10, 10,...) Are set up on the HST cover (8) and separated from each other by a certain distance, that is, close to the side of the floor (20). Therefore, handling during maintenance becomes easier.
Moreover, since the brake mechanism (11) comprising the inner expansion type is configured to be detachably attached to the vehicle body, the specification does not require an auto-cruise device (a brake mechanism that holds the rotation position of the shift pedal). When producing, the cost for this improvement can also be reduced.
Further, when the brake pedal (12) for braking the vehicle body is depressed , the auto-cruise is canceled, so that it is possible to prevent contact with an obstacle during traveling.

Further, according to the invention of claim 2, the throttle opening increases and the engine (E) speed increases as the vehicle speed is increased by depressing the speed change pedal (3, 4). There is an advantage that the engine stall is eliminated.

Hereinafter, an embodiment in which the cruise control device of the present invention is mounted on an agricultural tractor will be described with reference to the drawings.

As shown in FIGS. 1 to 3, the tractor 2 includes an engine E inside the hood at the front of the vehicle body, and the HST cover 8 and the transmission case 16 serving as the vehicle body are connected to the rear of the engine E. . The HST cover 8 is equipped with an HST (hydrostatic hydraulic continuously variable transmission) 1 as a continuously variable transmission, and the motor output rotation is switched between forward and reverse to perform forward / reverse switching of the vehicle. It is configured to perform step shifting.

Further, a steering handle 9 is provided in front of the cockpit S of the tractor 2 and the front wheels are steered left and right by rotating the handle 9, and a brake pedal 12 is provided on the floor 20 in front of the cockpit S. At the same time, a speed change pedal comprising a forward pedal 3 and a reverse pedal 4 is provided side by side, and the respective rotation bases are supported on the support shaft 5, and the output rotation of the motor of the HST 1 is switched between forward and reverse by a stepping operation, or It is configured to increase or decrease. Further, an auto cruise on / off lever 15 (on / off operation tool) is provided on the side of the cockpit S.

The configuration of the shift pedal will be described.

As shown in FIGS. 1 and 4, the forward pedal 3 has a base end portion of a pedal arm 3 a fixed to a support shaft 5, and the support shaft 5 is further connected to a trunnion shaft via a forward rod 21 and a trunnion arm 22. 7, the forward operation system link mechanism 6 is configured. Accordingly, when the forward pedal 3 is depressed, the base end portion of the pedal arm 3a rotates clockwise in FIG. 1 around the support shaft 5 to pull the rod 21, and then the trunnion shaft 7 via the trunnion arm 22. Is rotated to the arrow F side in the figure to increase the forward speed.

On the other hand, the reverse pedal 4 supports the base end portion of the pedal arm 4a so as to be rotatable with respect to the support shaft 5 outside the pedal arm 3a of the forward pedal 3, and further supports the support shaft 5 with the reverse rod 24, trunnion. The link mechanism 6 of the reverse operation system is configured by being connected to the trunnion shaft 7 via the arm 22. Therefore, when the reverse pedal 4 is depressed, the base end portion of the pedal arm 4a rotates counterclockwise in FIG. 4 around the support shaft 5 to push up the reverse rod 24, and then through the trunnion arm 22. The trunnion shaft 7 is rotated in FIG. 4 (arrow R side) to increase the reverse speed.

Further, behind the support shaft 5, a neutral cam arm 30 a having a reverse “<” shape in side view is supported, and the trunnion arm 22 is always urged by a spring 30 b so as to return to the neutral position. It has become. Thereby, when the forward / reverse pedals 3 and 4 are stepped on and released, the pedals 3 and 4 and the trunnion shaft 7 are automatically returned to the neutral position, and the vehicle speed becomes zero.

Further, the neutral cam arm 30a is configured to connect the rotating base portion to the throttle mechanism 31 of the engine E through the wire 7b. With this configuration, the engine E can cope with load fluctuations because the throttle opening increases and the engine E speed increases as the vehicle speed is increased by depressing the forward pedal 3 or the reverse pedal 4. There is an advantage that the engine stall is eliminated. Reference numeral 7c shown in FIG. 4 indicates a spring connected to the end of the wire 7b. By changing the length and the spring coefficient of the spring 7c, it corresponds to the specifications of the vehicle body or the engine or the type of work. The engine speedup operation can be adjusted.

The support shaft 5 extends through and supports the opposite side of the vehicle body of the tractor 2, more specifically, the side surface of the opposite HST cover 8 provided with the link mechanism 6. It is configured to be equipped.

Further, as shown in FIGS. 1 and 5, the inner expansion brake 11 is provided with a plurality of bosses 10, 10... The brake case 11c is detachably attached via the support, and the support shaft 5 is gently urged to the neutral position against the urging force of the neutral cam arm 30a in the gap between the HST cover 8 and the brake case 11c. The damper 19 is configured to be provided.

The support shaft 5 is rotatably supported inside the case 11c via a bearing.

The support shaft 5 has a brake drum 11b (cylindrical body) fixed to an end thereof, and a friction material supported on the brake case 11c side and slid against the inner surface of the drum inside the drum 11a. The brake arms 11a and 11a are provided. Further, on the outer surface of the brake case 11c, a brake operation arm 11d for expanding the brake arms 11a, 11a is rotatably supported, and the arm 11d is indicated by an arrow in FIG. By turning in the ON direction, the brake arms 11a, 11a expand outward and press against the inner peripheral surface of the brake drum 9 to give a braking force, thereby rotating the support shaft 5, that is, the forward pedal 3 The operation position is fixed.

Next, an on / off operation tool for operating the inner expansion brake 11 will be described.

The on / off operation tool is configured in a lever form (hereinafter referred to as an auto cruise on / off lever 15) and is configured to project and support on the fender 17 on the side of the cockpit S.

More specifically, the base of the lever 15 is rotatably supported with respect to the left and right lever support shaft P, and the lever arm and the brake operation arm 11d of the inward expansion brake are connected via a push-pull wire 18. It has a configuration. Further, as shown in FIG. 6, the lever support shaft P rotates a cylindrical shaft 13 having a short side arm 13a and a long side arm 13b projecting in a V shape outside the support portion of the lever 15. It is configured to support freely.

The short side arm 13a is connected to the rotating base of the brake pedal 12 via a push-pull wire 28, and the long side arm 13b is connected to the lever base of the auto cruise on / off lever 15. The locking pin 13p is projected. Further, a spring 14 is interposed between the short side arm 13 a and a bracket BR fixed to the fender 17.

The auto cruise on / off lever 15 configured as described above operates the inner expansion brake 11 as shown in FIGS.

The state shown in FIG. 6 shows a state in which the auto cruise on / off lever 15 is turned off, that is, a state in which the operation position of the forward pedal 3 is not fixed. From this state, the forward pedal 3 is depressed to drive the vehicle. When the vehicle speed is reached, the lever 15 is turned in the direction of the arrow in the drawing (rear of the vehicle body).

Then, as shown in FIG. 7, the auto-cruise on / off lever 15 is held in a state where the wire 18 of the base portion tilts backward beyond the fulcrum axis P as a fulcrum.

Accordingly, the brake operation arm 11d is rotated in the direction of the arrow ON in FIG. 5 via the push-pull wire 18, and the brake arms 11a and 11a inside the case are expanded to rotate the support shaft 5 at the rotational position. To fix. Therefore, the position of the forward pedal 3 is fixed and the vehicle speed is kept constant (automatic cruise entering state). To release the vehicle speed, the cruise control is turned off by tilting the on / off lever 15 forward.

Furthermore, when the brake pedal 12 is stepped on from the state of FIG. 7, the stepping operation is transmitted to the short side arm 13a through the pulling operation of the push-pull wire 28, and is integrated with the arm 13a. The side arm 13b is rotated clockwise about the axis P. Then, the locking pin 13p of the long side arm 13b comes into contact with the arm base portion of the auto cruise on / off lever 15, and the lever 15 is forcibly tilted forward of the vehicle body. Thereby, the cruise control is released.

Since the short arm 13a is biased to one side by the spring 14, the long side arm 13b retracts to the rear of the vehicle body after the brake pedal 12 is released.

In the tractor 2 configured as described above, compared to the conventional device, a link mechanism 6 from the shift pedals 3 and 4 to the trunnion shaft 7 of the HST 1 is provided on one side of the vehicle body, and an inwardly expanding brake 11 is provided on the other side. Since it is configured to be equipped, the space on both sides can be used effectively, and there is a margin in the surroundings, so there is an advantage that adjustment such as maintenance can be easily performed. Also, the inner expansion brake 11 is constructed such that the bosses 10, 10... Are raised from the HST cover 8 and separated from each other by a certain distance, that is, close to the side of the floor 20, so that the handling at the time of the maintenance is further performed. easy. Further, the inner expansion brake 11 is configured to be detachably attached to the vehicle body from the bosses 10, 10,..., So when producing specifications that do not require an auto cruise device depending on the tractor model, this improvement is provided. Such costs can also be reduced.

Further, when the auto cruise on / off lever 15 in the vicinity of the cockpit S is rotated back and forth, the inner brake is switched between an operating state (ON) and a non-operating state (OFF). Since the brake does not act on the motor, the operating force is light and the operability is good as compared with the conventional structure in which the friction pedal is provided with the friction material and the braking force is always applied. Further, in the above-described configuration, when the brake pedal 12 is depressed, the auto-cruise on state can be released simultaneously with the brake operation, so that the vehicle is immediately stopped when avoiding contact with an obstacle during traveling. can do. Further, since the cruise control device is composed of mechanical parts such as wires and rods, the manufacturing cost is lower than that of electrical parts.

Further, as another form of the cruise control device, the brake 11 may be configured to hold the position of the reverse pedal 3, and the on / off device may be configured as a push-in switch type or a dial type. good. Further, the brake mechanism 11 may be configured by an electromagnetic clutch type brake or a dog clutch type lock device instead of the internal expansion type brake.

Next, the configuration of the safety frame 40 will be described based on FIGS. 9 to 11.

The safety frame 40 of the tractor 2 includes a front-view loop-shaped upper frame 40a and left and right lower frames 40b and 40b, and is configured to be foldable into two-folded states (see FIG. 11) at this connection portion. Yes.

However, when working with the tractor 2, a work machine is often mounted on the rear part of the vehicle body. In the above configuration, the upper frame 40 a comes into contact with the work machine, and the tree such as an orchard is connected with the upper frame connected. There was a problem that it was not possible to work under and under the house.

Therefore, as described above, the safety frame capable of tilting the upper frame 40a rearward at the connection portion as described above is configured to include a regulating tool that regulates the tilt angle.

Specifically, a connecting bracket 41a is provided at the lower left and right ends of the upper frame 40a so that the left and right fixing pins 42 are inserted into the front surface and the rotating pin 43 is inserted into the rear surface. Similarly, a connecting bracket 41b is provided through which the fixing pin 42 in the left-right direction is inserted in the front surface and the rotation pin 43 is inserted in the rear surface.

As a result, the upper frame can be tilted to the rear of the vehicle body around the rotation pin 43 by removing the fixing pin 42 on the front surface of the upper and lower frames. Further, an L-shaped locking plate 44 in a side view is attached to the rear surface of the connecting bracket 41b of the lower frame 40b with a bolt 45 so as to be switched up and down with respect to the bracket 41b.

Thus, during normal operation, the upper frame 40a is erected and travels on the tractor 2, and when the work implement is not mounted on the rear portion, as shown in FIG. 11, the locking plate 44 projects downward. Install it in the installed state. Thereby, the upper frame 40a can fall down in a state of being substantially folded with respect to the lower frame 40b.

Further, when the work machine is attached to the rear part of the vehicle body, it is attached with the locking plate 44 protruding upward. As a result, when the upper frame 40a is tilted rearward, the upper end portion of the locking plate 44 can face the connection bracket 41a of the upper frame 40a, and the tilt angle of the upper frame 40a can be regulated at a predetermined angle. it can.

Therefore, when moving under a tree such as an orchard or traveling in a house, it is possible to travel with the work frame attached and the height of the safety frame lowered. Compared with the structure to remove, operation is reduced and operability is good.

The top view of the vehicle body center part of a tractor. The left view of a tractor. The right view of a tractor. The side view which shows the link mechanism of the forward / reverse pedal base. The side view which shows an auto cruise on / off lever and a brake mechanism. The side view of the auto cruise on / off lever which shows an auto cruise "off" state. The side view of the auto-cruise on / off lever which shows an auto-cruise "on" state. The side view of the auto-cruise on / off lever which shows the effect | action which returns auto-cruise from "ON" to "OFF" by brake operation. The side view of a safety frame. The connection part perspective view of a safety frame. The side view when a safety frame is bent backward.

E engine S cockpit 1 HST (continuously variable transmission)
2 Tractor 3 Forward pedal 4 Reverse pedal 5 Support shaft 6 Link mechanism 7 Trunnion shaft (speed change operation shaft)
7b Wire 8 HST cover (vehicle body)
9 Brake drum 10 Boss 11 Brake mechanism 11a Brake arm 11b Cylinder 11c Brake case 12 Brake pedal 14 Spring 15 Operation tool (auto cruise on / off lever)
17 Fender 19 Damper 22 Trunnion arm 30a Neutral cam arm 30b Spring 31 Throttle mechanism

Claims (2)

A work vehicle equipped with a continuously variable transmission (1) and configured to be able to switch between forward and reverse movements and to increase and decrease speeds by depressing a shift pedal (3, 4) in the vicinity of a cockpit (S). The transmission pedal (3, 4) is supported by a support shaft (5) protruding from the side of the vehicle body, and the stepless transmission (1) protruding from the pedal (3, 4) base and the same side of the vehicle body. ) Is connected to the speed change operation shaft (7) via the link mechanism (6) so that the speed change operation shaft (7) can be rotated by depressing the pedal (3, 4) and integrated with the pedal base. The support shaft (5) thus configured is extended to the other side of the vehicle body and is provided with a brake mechanism (11) that holds the rotational position of the support shaft (5) at the end. The transmission operation shaft (7) and the trunnion arm (22) are connected, and the neutral shaft is located behind the support shaft (5). The cam arm (30a) is supported, and the trunnion arm (22) is always returned to the neutral position via the neutral cam arm (30a) by the spring (30b), and the rotational position of the support shaft (5) is maintained. The brake mechanism (11) includes a brake arm (11a, 11a) that is expanded around the coaxial (5) and supported on the vehicle body side, and a cylindrical body (11b) that rotates integrally with the coaxial (5). It is composed of an expansion brake, and this inner expansion brake has a plurality of bosses (10, 10,...) On the side of the HST cover (8) that houses the continuously variable transmission (1). And the brake case (11c) is detachably attached to the end portions of the plurality of bosses (10, 10,...) Via a plate. The HST cover (8) and the brake case 11c) is provided with a damper (19) for gently urging the support shaft (5) to the neutral position against the urging of the neutral cam arm (30a). Further, the brake mechanism (11 ) Is operated to be turned on and off by an operating tool (15) provided on a fender (17) in the vicinity of the cockpit (S), and provided on the shift pedal (3, 4) side, the brake pedal (12 ) depression operation result, a working vehicle, characterized in that the operating member (15) is operated and configured to release the auto-cruise filled state.   The work vehicle according to claim 1, wherein the rotation base of the neutral cam arm (30a) is connected to a throttle mechanism (31) of the engine (E) via a wire (7b).

Images