JPH06191314A - Accelerator control structure for working vehicle - Google Patents

Abstract

PURPOSE:To provide an accelerator control mechanism capable of avoiding to stop an engine by the engagement operation of a PTO clutch to drive a working device. CONSTITUTION:An accelerator control structure for working vehicle is provided with a first accelerator control means 30 to control a speed governing lever 13a of a speed governing mechanism 13 of an engine 5 from the minimum speed rotation position MIN to the maximum speed rotation position MAX by an accelerator setting device 24 and a second accelerator control means 31 to control the speed governing lever 13a to a high rotation position set in preference to the first accelerator control means 30 by the engagement of a clutch by a PTO clutch lever 12. Also it is provided with a restriction means 33 to restrict the movement of a connecting member 19, which is located in a connecting mechanism for the PTO clutch lever 12 and a speed governing mechanism 13, from a position corresponding to a preset high speed rotation position to a high speed rotation position, and an elastic interchange mechanism 34 to enable operation of the PTO clutch lever 12 to the clutch engagement side even after it has been restricted by the restricting means 33 in the connecting mechanism for the connecting member 19 and the PTO clutch lever 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a first accelerator operating means for operating a speed control lever of a speed control mechanism provided in an engine from a minimum rotational position to a maximum rotational position based on manual operation of an accelerator setting tool, and a PTO. An accelerator for a work vehicle including a second accelerator operating means for forcibly operating the speed governing lever to a preset high rotation position in preference to the accelerator setting by the first accelerator operating means based on a clutch engagement operation of the clutch lever. Regarding operation structure.

[0002]

2. Description of the Related Art Conventionally, an accelerator operating structure for a work vehicle of this type was previously filed by the present applicant (Japanese Patent Application No.
No. 102726), the engine rotation is at the maximum speed so that the speed control lever is operated to a high rotation position in conjunction with the operation of entering the PTO clutch lever to obtain power for driving the working device while traveling. It was designed to be

[0003]

However, in the accelerator operating structure of the above-described conventional work vehicle, the PTO
Since the clutch lever enters the first position, a load is added to drive the work equipment in a low torque state where the engine speed is not high, and the engine cannot output the driving force for that load. There was a risk that it would stop. The present invention has been made in view of the above circumstances, and even when the PTO clutch is operated to be driven in order to drive the work device, it is possible to prevent the engine from being stopped due to the engagement operation. The purpose is to provide the structure.

[0004]

In order to achieve the above-mentioned object, an accelerator operating structure for a work vehicle according to the present invention is based on the manual operation of an accelerator setting tool by a speed-adjusting lever of a speed-adjusting mechanism provided in an engine. A first accelerator operating means for operating from a minimum rotation position to a maximum rotation position, and a high rotation speed which is set in advance on the basis of the clutch engagement operation of the PTO clutch lever, prior to the accelerator setting by the first accelerator operating means. A second accelerator operating means for forcibly operating to a position, and in the second accelerator operating means, the preset setting of the linking member interposed in the linking mechanism for linking and linking the PTO clutch lever and the speed control mechanism. A restricting means for restricting movement to a rotational position higher than a position corresponding to the high rotational position is provided, and further, the linking member and the PTO clutch are provided. During linkage mechanism for linking the Chireba further the PTO even after being regulated by the regulating means
A characteristic feature is that an elastic accommodation structure is provided for enabling the clutch lever to be operated toward the clutch engaged side. The operation and effect of this characteristic configuration are as follows.

[0005]

In other words, if the correspondence relationship between the PTO clutch lever and the engaged position of the clutch is set near the limit of the operation of the PTO clutch lever into the clutch engagement box, the flexible range of the elastic accommodation structure of the PTO clutch lever can be set. The speed control lever is operated to the high rotation position before reaching P., and the speed control lever is not operated any more, but the PTO clutch lever is actually moved to the clutch engaged position, and then the actual P
Since the TO clutch can be switched to the engaged state, the working device and the engine are interlocked and coupled in a high torque state where the engine output is high. Further, since the PTO clutch lever can elastically bias the high speed rotation further while the speed adjusting lever is restricted to the high rotation position by the elastic accommodation mechanism, the linkage mechanism that links the speed adjusting lever and the PTO clutch lever. The slack will not occur and the speed control lever will not be displaced at a low speed from the high rotation position.

[0006]

Therefore, since the working device and the engine are interlocked and coupled in a high torque state where the engine output is high, there is no problem that the engine is stopped even if a load for driving the working device is applied to the engine. In addition to the solution, it has become possible to solve the problem that the speed control lever in the state of being operated to the high rotation position is displaced at a low speed due to slack of the linkage member.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 shows a riding lawn mower as an example of a work vehicle according to the present invention. This riding type lawnmower is configured as a mid mount type equipped with a mower 4 between front and rear wheels 2 and 3 of a riding traveling vehicle body 1, and a part of the output of a vertical axis type engine 5 mounted on the rear portion of the vehicle body is belted. It is configured to be transmitted to the rear wheel 3 via the transmission device 6, the hydrostatic continuously variable transmission device 7 and the transmission case 8 and to transmit another part of the engine output to the mower 4 via the belt transmission device 9. is doing. The hydrostatic continuously variable transmission 7, which is a traveling transmission device, is capable of forward or backward continuously variable transmission by stepping forward or backward of a speed change pedal 10 as a traveling speed change operation tool. , A tension-type PTO clutch 11 provided in the belt transmission device 9
Can be turned on and off by the PTO clutch lever 12 at the driver's hand.

Next, the speed control mechanism 13 provided in the engine 5
The operation structure of will be described. As shown in FIGS. 1 to 3, the speed control lever 13a of the speed control mechanism 13 provided in the engine 5 is biased to the minimum rotation position (idling position) MIN, and the wire led out from the speed control lever 13a. 14 is attached to a first rotating member 15 mounted so as to be rotatable around the axis P. The support shaft 16 on which the first rotating member 15 is mounted is installed on a sheet metal supporting case member 17 provided on the riding vehicle body 1. And the first
The rotating member 15 is the step portion 1 formed on the support case member 17.
7a is provided with a locking portion 15a that is locked to the stepped portion 17a so as to be regulated at the minimum rotation position MIN. First
The fourth rotation member 18 is provided on each side of the rotation member 15.
A third rotating member 19 as a linking member is attached to the support shaft 16 so as to be rotatable around the axis P. Fourth rotating member 1
A wire 20 drawn out from the speed change pedal 10 is attached to the neutral position 8 by being biased to the neutral wire. A wire 21 led out from the PTO clutch lever 12 is attached to the third rotating member 19 by urging the off operation into a crocodile. The second rotating member 22 adjacent to the third rotating member 19 on the opposite side to the first rotating member 15 is attached to the support shaft 16 by the axis P.
It is mounted so that it can rotate around it. The second rotating member 22 is configured to be held by friction by being pressed against the support case member 17 by a disc spring 23, and a hand accelerator lever 24 as an accelerator setting tool is continuously provided. Here, the wire 14 and the first rotating member 15
Is a component of the first accelerator operating means 30,
The wire 21, the third rotating member 19, and the pin 25 are
The accelerator operation means 31 is configured.

As shown in FIG. 3, a pin 25 as an operating member extends parallel to the shaft center P on the opposite side of the first rotating member 15 with the engaging portion 15a sandwiching the support shaft 16. It is protruding on both left and right sides. And this pin 2
Reference numeral 5 denotes elongated holes 22A, 19A, 18 formed in the second rotating member 22, the third rotating member 19, and the fourth rotating member 18, respectively.
It is inserted through A. These long holes 22A, 19A, 18
A is formed in an arc shape with the axis P as the center, and is flexible so as to allow the pin 25 to move to the groove that accelerates the first rotating member 15, and these elongated holes 22A, 19 are provided.
The ends of the upper hand of the rotation of A and 18A to the speed-increasing girth are abutting parts 22a, 19a and 18a which abut the pin 25. The contact portion 22a of the elongated hole 22A of the second rotating member 22 is set by swinging the hand accelerator lever 24 when the PTO clutch lever 12 is in the off operation state and the speed change pedal 10 is in the neutral state. The pin 25 is pressed and moved to an arbitrary operation position to move, and the first rotation member 15 is moved.
Is operated to rotate the speed control lever 13a to an arbitrary state, and the disc spring 23 holds the friction position.
Further, the contact portion 19a when the PTO clutch lever 12 is in the off operation state is adapted to contact the pin 25 when the first rotating member 15a is at the minimum rotation position MIN, and the PTO clutch lever When 12 is turned on, the third rotation member 19 rotates, and the contact portion 19a presses the pin 25 which is set by the hand accelerator lever 24 and located in the middle of the slot 19A. Moving member 15
Is rotated to the maximum rotation position MAX. On the other hand, the contact portion 18a when the speed change pedal 10 is in the neutral state is adapted to contact the pin 5 when the first rotation member 15 is at the minimum rotation position MIN, and
When the shift pedal 10 is stepped forward to increase the speed, the speed control lever 13a is not operated by operating the shift pedal 10 until the contact portion 18a contacts the pin 25. In the operation of increasing the speed of the pin 18a after the pin 18a contacts the pin 25, the pin 25 is pressed by the contact part 18a and the high-speed rotation is tapped from the speed adjusting position set by the hand accelerator lever 24. become. And the shift pedal 1
When 0 is operated at the highest speed, the speed control lever 13a is also operated to the highest rotation position MAX as the high rotation position.

Further, as shown in FIGS. 1 and 2, the first rotating member 15 is arranged so that the rotating position of the third rotating member 19 and the rotating position of the first rotating member 15 correspond to each other. Maximum rotation position M
At a position corresponding to AX, there is provided a restricting means 33 for restricting the third rotating member 19 so that a higher position higher than the maximum rotating position MAX cannot be displaced. The restricting means 33 is a restricting member 33a protruding from a predetermined portion of the third rotating member 19 and a restricting member protruding from the inner wall portion of the support case member 17 so that the protruding member 33a abuts on the protruding member 33a. Piece 33b
It consists of and. Further, a tension spring 34 as an elastic accommodation structure is interposed between the wire 21 and the PTO clutch lever 12.

With the above structure, the PTO clutch lever 1
When 2 is turned off and the operation position enters the operation position,
First, the third rotating member 19 is rotated through the tension spring 34 and the wire 21 in conjunction with the operation of the lever 12, and the pin 25 is brought into contact with the contact portion 19a of the elongated hole 19A along with the rotation. The first rotating member 15 is pushed to rotate the first speed control member 15 at a high speed, and the speed adjusting lever 13 a is swung at a high speed through the wire 14. Then, when the speed control lever 13a is operated to the maximum rotation position MAX, the high-speed operation of the third rotating member 19 is suppressed due to the contact restriction between the protruding piece 33a and the restriction piece 33b of the restriction means 33. The rotation is regulated, and the PTO is still in the regulated state.
Although the clutch 11 is not engaged, the PTO clutch lever 12 can be oscillated while extending the tension spring 34 from the regulated position to the engaged position of the clutch, and the PTO clutch 11 is in the engaged position at the engaged position. Become. Further, the PTO clutch lever 12 operated to the clutch engaged position is held in position against the urging force of the tension spring 34 by a friction holding mechanism or the like (not shown). Therefore, as it is, the PTO clutch lever 12
Is held in the clutch engaged position, the tension spring 34 causes the third rotating member 19 to move to the regulating means 33.
The attitude is maintained while being restricted by, and the attitude of the first rotating member 15 is also maintained to maintain the speed control lever 13a at the maximum rotation position MAX.

Next, the lock structure 35 for locking the parking brake in the operated state will be briefly described. As shown in FIG. 4, a notch in which a rod member 39 linked to a parking brake lever 38 can be fitted to a pedal shaft 37 linked to a shift pedal 36 for shifting the hydrostatic continuously variable transmission 7. A locking plate 41 having a portion 40 is fixed. As shown in FIG. 4, the rod member 39 is inserted into the cutout portion 40 of the locking plate 41 and the parking brake lever 3 while the parking brake lever 38 is being operated.
When the brake pedal 8 is operated to the brake release state, the lock plate 41 is retracted from the notch 40. Then, the cutout portion 40 has side edge portions 40a, 40 such that the width of the cutout portion becomes narrower toward the opening than at the back side thereof.
It is formed in a state in which a is inclined so as to face inward.
As a result, even if the shift pedal 36 is operated while the parking brake is being braked, the side edge portions 40a, 40a of the cutout portion 40 contact the rod member 39, and the rod member 39 cuts out the cutout portion 40. I try not to get out of the opening.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a first part of an accelerator operating structure in a low speed operation state.
To explanatory views showing the disassembled longitudinal structure of the fourth rotating member and the lever and the like linked to them

FIG. 2 is an explanatory diagram showing a disassembled longitudinal structure of the first to fourth rotating members in the accelerator operating structure when the PTO clutch lever is operated to be engaged and disengaged, and levers and the like linked thereto.

FIG. 3 is a cross-sectional plan view showing an accelerator operating structure.

FIG. 4 is a vertical sectional side view showing a lock structure of a parking brake.

FIG. 5 is an overall side view showing a riding lawn mower.

[Explanation of symbols]

 5 engine 12 PTO clutch lever 13 speed control mechanism 13a speed control lever 19 linking member 24 accelerator setting tool 30 first accelerator operating means 31 second accelerator operating means 33 regulating means 34 elastic accommodation structure MIN minimum rotation position MAX maximum rotation position

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ryozo Imanishi 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Nobuyuki Yamashita 64, Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. (72) Inventor Sataya Harada 64, Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Inventor, Katsuhiko Uemura 64, Ishizukitamachi, Sakai City, Osaka Prefecture (72) Invention Person Mikio Yuki 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Inventor Hiroyuki Ogasawara 64, Ishizukitamachi, Sakai City Osaka Prefecture Kubota Sakai Factory Co., Ltd.

Claims (1)

[Claims] 1. A speed control mechanism (1) provided in an engine (5).
Set the speed control lever (13a) of 3) to the accelerator setting tool (24).
The first accelerator operating means (30) for operating from the minimum rotation position (MIN) to the maximum rotation position (MAX) based on the manual operation of the above, and the speed control lever () based on the clutch engagement operation of the PTO clutch lever (12). 13a) is provided with a second accelerator operating means (31) for forcibly operating to a preset high rotation position in preference to the accelerator setting by the first accelerator operating means (30), and the second accelerator operating means (31) ), Rotation higher than the position corresponding to the preset high rotation position of the linkage member (19) interposed in the linkage mechanism for interlockingly connecting the PTO clutch lever (12) and the speed governing mechanism (13). A linking mechanism that links the linking member (19) and the PTO clutch lever (12) with a restricting means (33) that restricts the movement to the position. The elastic flexibility structure to further the PTO clutch lever even after being restricted (12) operable to clutch engaging side by the regulating means (33) (3
4) The structure for operating the accelerator of a work vehicle.