JPH05178118A - Speed governing operating structure of working vehicle - Google Patents

Abstract

PURPOSE:To simplify the structure of a device and make the device in a compact size by providing an electromagnetic speed maintaining means comprising an operated member moving integrally with a speed governing operating means and a solenoid capable of applying the frictional force to the operated member by electromagnetic force. CONSTITUTION:When a speed governing pedal 11 is actuated for a designated amount to turn on an operation switch 16, an electric current is applied to an electromagnet 15, the electromagnet 15 slides against a return sprung to attract a suction rung 13, and the suction ring 13 is fixed and maintained by electromagnetic frictional force, that is, a solenid brake, thereby entering the auto cruise condition, with the speed governing pedal 11 fixed and maintained in an arbitrary actuating position. If the operation switch 16 is turned off, or a cancel switch 18 is operated by actuating a brake pedal 19, the fixing and maintaining condition of the suction ring 13 is released to cancel the cruising condition, so that it returns to the normal operation form.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work vehicle such as a lawn mower and a tractor, and more particularly, to a speed at which a speed control operating tool of a continuously variable transmission for traveling can be fixedly maintained and released at an arbitrary operating position. The present invention relates to a maintenance vehicle, a work vehicle provided with a so-called automatic cruise device.

[0002]

2. Description of the Related Art A conventional auto cruise device is disclosed in Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Publication No. 190553, by operating a manual operation lever which is interlocked with an operation pedal for traveling, a speed-regulating pedal that has been stepped on can be fixedly maintained at the stepped-on position, and its maintenance is fixed. The means has a mechanical structure in which the frictional force of pressing the disks of the operating shaft against each other by the urging force of the spring is utilized.

[0003]

However, the mechanical type auto-cruise device is apt to have a complicated structure due to its mechanical structure and its own space is relatively large. Therefore, the layout efficiency of the operating mechanism of the device is high. There seems to be room for improvement in terms of. An object of the present invention is to provide an automatic cruise device having a simple structure and a more compact structure.

[0004]

In order to achieve the above object, the present invention provides a speed maintaining means capable of fixing and maintaining a speed control operation tool of a continuously variable transmission for traveling at an arbitrary operation position. In addition, the speed maintaining means is configured to be an electromagnetic type including an actuated member that moves integrally with the speed control operation tool and a solenoid that can apply a frictional force to the actuated member by an electromagnetic force. Characteristic configuration.

[0005]

In other words, since the frictional force for fixing and maintaining the speed-adjusting operation tool is electromagnetic rather than mechanical, only the wiring is required as the linking mechanism with the operating side, and the installation space as the linking mechanism is required. Can be made smaller than in the past. Further, conventionally, a manual operation against the biasing force of the spring was required, but with the electromagnetic type, a simple and labor-free operation such as a switch operation is sufficient.

[0006]

Therefore, by changing the structure of the speed maintaining means from the mechanical type to the electromagnetic type, it is possible to provide an automatic cruise device having a simple structure and a more compact structure. This has no advantage when it is installed in a small model.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a lawnmower, which is an example of a work vehicle.
Is a front wheel, 2 is a rear wheel, 3 is a mower, 4 is a control unit, 5 is an engine, 6 is a driver's seat, and 7 is a mission for traveling. The mission 7 is equipped with an HST (hydrostatic hydraulic continuously variable transmission) 8, a switching lever 10 for swinging an operated arm 9 mounted on a trunnion shaft 8a thereof, and a speed control pedal (speed control tool) 11 Is linked and linked, and speed control pedal 11
Is provided at a desired operating position with a speed maintaining means A capable of being fixedly maintained and released. That is, as shown in FIG. 1, an attracted ring (corresponding to an actuated member) 13 is loosely fitted onto a support shaft 12 of a speed control pedal 11, and a disc spring 14 is fitted to a body so as to rotate integrally. An electromagnet (solenoid) 15 is arranged at a position near the side of the attracted ring 13 in a state where a slight movement in the axial direction of the support shaft 12 is allowed, and the speed maintaining means A is provided.
Is configured. The clearance S between the electromagnet 15 and the attracted ring 13 can be changed and adjusted by moving the attracted ring 13 and the disc spring 14 in the axial direction by operating the two nuts of the support shaft 12. The operation switch 16 for turning on and off the power supply to the electromagnet 15 is provided in the steering wheel 1.
A cancel switch 18, which is provided at the left lateral position of 7, and which can cut off energization to the electromagnet 15 separately from the operation switch 16, is provided in a state of being operated in accordance with the depression operation of the brake pedal 19. .. In addition, the reverse detection switch 20 that operates when the speed control pedal 11 is in the neutral position, near the neutral position, or in the reverse position is provided with the changeover lever 10.
And a tachometer 21 for detecting the number of revolutions of the engine 5 are connected to the control device 22, respectively, and the electromagnet 15 and the operation switch 16 are also provided in the control device 2.
2 to form a control circuit.

Explaining the operation of this control circuit, when the speed control pedal 11 is depressed by a predetermined amount and then the operation switch 16 is turned on, the electromagnet 15 is energized and the electromagnet 15 slides against a return spring (not shown). Then, the attracted ring 13 is attracted, and the attracted ring 13 is fixed and maintained by an electromagnetic frictional force, that is, an electromagnetic brake, so that the speed regulating pedal 11 is fixed and maintained at an arbitrary stepped position, and an automatic cruise state can be achieved. And the operation switch 16
When either the switch is turned off or the cancel switch 18 is operated by depressing the brake pedal 19, the fixed maintaining state of the attracted ring 13 is released, the cruise is released, and the normal operation mode is restored. When the HST 8 is speed-adjusted to the slow forward, neutral, or reverse position by the action of the reverse detection switch 20, even if the operation switch 16 is turned on, the electromagnet 15 is not energized and the auto cruise state cannot be set. As described above, the control device 22 is made to function, and in an emergency such as a sudden braking even in the auto cruise state, the HST 8 by depressing the speed control pedal 11 is set.
The biasing force of the disc spring 14 to the attracted ring 13 is set so that the neutral operation can be performed. In addition, based on the information detected by the tachometer 21 that the running load has increased and the engine speed has fallen below the set range in the auto cruise state, the electromagnet 15 is de-energized and the cruise is automatically canceled. The control device 22 is also provided with such a function.
For reference, FIG. 2 shows a flowchart of the control operation.

[Other Embodiment] The reverse detection switch 20 may be equipped so as to act on a cam attached to the speed control pedal 11. Then, of the pair of oil passages connecting the hydraulic motor and the hydraulic pump in the HST 8, a pressure switch is provided in the oil passage on the discharge side in the forward traveling state, and if the pressure switch detects a pressure equal to or higher than a predetermined value, the forward movement is performed. Alternatively, it may be determined that the electromagnet 15 is in the state, and the electromagnet 15 is controlled to be energized so that the auto cruise can be performed only in this state. Further, the electromagnet 15 may have a structure in which the supporting plate portion of the speed control pedal is directly attracted, and the supporting plate portion and the attracted ring 13 are collectively referred to as an actuated member.

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

[Brief description of drawings]

FIG. 1 is a system diagram showing a control circuit of speed maintaining means.

FIG. 2 is a flowchart showing a control operation.

[Figure 3] Side view of the lawn mower

[Explanation of symbols]

 8 continuously variable transmission 11 speed control operation tool 13 acted member 15 solenoid A speed maintaining means

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[Procedure amendment]

[Submission date] May 7, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

Explaining the operation of this control circuit, when the speed control pedal 11 is depressed by a predetermined amount and then the operation switch 16 is turned on, the electromagnet 15 is energized and the electromagnet 15 slides against a return spring (not shown). Then, the attracted ring 13 is attracted, and the attracted ring 13 is fixed and maintained by an electromagnetic frictional force, that is, an electromagnetic brake, so that the speed regulating pedal 11 is fixed and maintained at an arbitrary stepped position, and an automatic cruise state can be achieved. Auto cruise state canceled
What is done is the following case, that is, a decrease from the set range of the engine rotation in which the speed-adjusting pedal 11 that depresses the brake pedal 19 that operates the operation switch 16 is operated backward . When either the operation switch 16 is turned off or the cancel switch 18 is operated by depressing the brake pedal 19, the fixed maintaining state of the attracted ring 13 is released, the cruise is released, and the normal operation mode is restored. And speed control
When the HST 8 is speed-regulated to the slow forward, neutral, and reverse positions by the operation of the reverse detection switch 20 by the operation of the pedal 11, even if the operation switch 16 is turned on, the electromagnet 15 is not energized and the auto cruise is performed. The control device 22 functions so that it cannot be put into a state . For speed maintenance means A
The biasing force of the disc spring 14 to the attracted ring 13 controls the speed.
Set the strength so that the pedal 11 can be forcibly depressed.
Therefore, the speed control pedal 11 can be
Then, you can return to the cruise cancellation state. In other words, oh
Set the speed control pedal 11 near neutral even in the auto cruise state.
Or you can cancel the cruise by operating to the reverse position,
The operating state (slow forward, neutral, or reverse)
It will be revealed. This is a quick shake with neutral operation.
Effectively works even in an emergency such as a brake. In addition, based on the information detected by the tachometer 21 that the running load has increased and the engine speed has fallen below the set range in the auto-cruise state, the electromagnet 15 is de-energized and the cruise is automatically canceled. The control device 22 is also provided with such a function. For reference, FIG. 2 shows a flowchart of the control operation.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Nobuyuki Yamashita Nobuyuki Yamashita 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Kazuaki Kurohara 64, Ishizukita-machi, Sakai City, Osaka Kubota Sakai Co., Ltd. Inside the factory

Claims (1)

[Claims] 1. A speed maintaining means (A) capable of fixing and maintaining a speed control operation tool (11) of a continuously variable transmission (8) for traveling at an arbitrary operating position, and maintaining the speed. An actuated member (13) that moves the means (A) integrally with the speed control operation tool (11), and the actuated member (13).
A solenoid (1 that can apply frictional force to the
5) The structure for electromagnetically controlling the work vehicle, which is composed of 5) and 5).