JPH08210478A - Speed change operating structure for work vehicle - Google Patents

Abstract

PURPOSE: To lightly operate an operating lever, even in the case of large operating reaction force from a static hydraulic continuously variable transmission by generating a large running load, by disconnecting an electromagnetic clutch to release friction holding by a friction holding mechanism when operated the operating lever. CONSTITUTION: In a running control system of a combine, a speed change operating fixture 8 of a static hydraulic continuously variable transmission 3 and a manual operating lever 7 are connected association operably, to provide detecting parts SW1, SW2 of detecting an operating direction of this manual operating lever 7. Based on detection information of the detecting parts SW1, SW2, an electromagnetic clutch 11 is set to a disconnecting condition by a clutch control means C, thus to release friction holding by a friction holding mechanism 12, so as to lightly perform speed change operating the speed change operating fixture 8 by the manual operating lever 7. In an automatic speed change mode, the electromagnetic clutch 11 is connected, to automatically operate a drive mechanism 10 by an automatic speed change control means A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention links a speed change operation tool and a manual operation lever of a hydrostatic continuously variable transmission in an interlockable manner, and automatically operates the speed change operation tool via a friction holding mechanism. A drive mechanism is provided to provide automatic shift control means for automatically operating the drive mechanism based on a work situation regardless of the operation position of the manual operation lever, and an electromagnetic clutch controlled to be turned on and off by the clutch control means is provided. The manual operation lever and the drive mechanism are linked to each other, and a detection unit for detecting that the manual operation lever is operated in either forward or backward direction is provided, and based on the detection information from the detection unit,
The present invention relates to a gear shift operation structure for a work vehicle, which is provided with a manual gear shift control means for driving and controlling the drive mechanism in accordance with an operating direction of the manual operation lever.

[0002]

2. Description of the Related Art Conventionally, in a gear shift operation structure for a work vehicle, as shown in, for example, Japanese Patent Application Laid-Open No. 4-15365, friction is provided in the middle of a linkage mechanism of a manual shift lever for a hydrostatic continuously variable transmission. Selectable between a manual speed change state in which the manual operation lever is held at an arbitrary set speed position through an automatic holding mechanism and an automatic speed change state in which the transmission is automatically changed by an electric motor controlled based on the engine load. There was one that could be configured.

[0003]

In the above conventional structure, a friction type position holding mechanism is interposed to hold the operating lever at an arbitrary set speed position against the neutral restoring force of the continuously variable transmission. Therefore, the lever must be operated against this friction holding force in the manual shift operation by the operation lever, which requires a large operation force and leaves room for improvement in terms of operability.

Therefore, the manual operation lever and the drive mechanism are linked with each other via an electromagnetic clutch which is controlled to be engaged / disengaged by the clutch control means, and the electromagnetic clutch is disengaged to hold the friction of the operation lever by the friction type position holding mechanism. A structure has been proposed in which the lever is manually operated after being released.

However, even if the electromagnetic clutch is disengaged during the manual operation to release the friction holding of the operating lever by the friction type position holding mechanism, the speed increasing operation is performed under a heavy traveling load such as when turning a ridge. When doing, the large operation reaction force from the hydrostatic continuously variable transmission directly acted on the operation lever, and the operation of the operation lever was likely to be heavy.

The present invention has been made in view of the above circumstances, and an object thereof is to operate the operation lever even when the traveling load is large and the operation reaction force from the hydrostatic continuously variable transmission is large. It's about being able to do it lightly.

[0007]

According to a characteristic configuration of the invention according to claim 1, the clutch control means is configured so that the electromagnetic clutch can be controlled to be turned on and off based on the detection information from the detection section, and based on the detection information. , The electromagnetic clutch is set to the disengaged state, and the manual operation lever in a state where the friction holding by the friction type holding mechanism is released is set to the manual shift mode in which the shift operation tool can be operated to shift, and the electromagnetic clutch is set to the engaged state. Then, based on the detection information, the automatic shift mode in which the drive mechanism is automatically operated by the automatic shift control means, the electromagnetic clutch is set to the engaged state, and the drive mechanism is set in the operating direction of the manual operation lever. A shift mode switching means for switching the shift mode to an assisted manual shift mode for driving the automatic shift control means, the manual shift control means, and the clutch control means. Some that are provided for.

According to a second aspect of the present invention, in the first aspect of the invention, a vehicle speed detecting sensor and a turning detection sensor of the machine body are provided, and the vehicle speed detecting sensor detects a value smaller than a set value, and When the turning detection sensor detects the turning state of the machine body, the shift mode switching means is configured to automatically switch the shift mode to the assisted manual shift mode based on both detection information. is there.

[0009]

According to the first aspect of the present invention, the clutch control is performed based on the detection information from the detection unit that the operation lever is operated when the operation lever is operated to move forward or backward in the manual speed change mode. The electromagnetic clutch is disengaged by the means. As a result, in a state in which the friction holding by the friction holding mechanism is released, the manual operation lever can perform a gear shift operation with a light operating force to set the machine body traveling speed to an arbitrary gear shift position. Since the operation reaction force from the hydrostatic continuously variable transmission acts on the manual operation lever, the operation force does not become too light, and it is possible to easily and reliably set the target shift position. .

In the automatic shift mode, when the electromagnetic clutch is set to the engaged state and the work load such as the threshing work load becomes large, the transmission mechanism is operated by the drive mechanism regardless of the set speed of the manual operation lever. Then, the vehicle automatically decelerates, and problems such as engine stop are prevented.

In the assisted manual shift mode, when the forward / backward shift operation is performed by the manual operation lever, the electromagnetic clutch is engaged by the clutch control means based on the detection information from the detection unit that the manual operation lever is operated. The manual shift control means drives the drive mechanism in accordance with the operation direction of the manual operation lever while the operation lever is held in friction by the friction type holding mechanism. Therefore, even when a large operation reaction force from the hydrostatic continuously variable transmission directly acts on the operation lever when the speed increasing operation is performed in a state where the traveling load is large, for example, when turning the ridge, The operation lever can be lightly operated by the driving force of the drive mechanism. When the operation lever is stopped at an arbitrary gear shift position, the manual gear shift control is stopped based on the detection information from the detector, and the vehicle travels at a speed corresponding to the gear shift position.

According to the second aspect of the present invention, for example, the vehicle speed detection sensor detects a value in a low speed state smaller than the set value when the vehicle starts to turn the ridge, and the turning detection sensor detects the turning state of the machine body. Then, the shift mode is automatically switched to the assisted manual shift mode based on the detection information from the both detection sensors. Since the shift mode is automatically switched to the assist manual shift mode in this way, the driver does not have to switch to the assist manual shift mode each time he / she turns in the ridge line, which increases the running load. The labor of operation can be saved.

[0013]

Therefore, in the manual speed change mode, the manual operation lever is used to change the speed with a small operating force in a state where the friction holding by the friction type holding mechanism is released, so that the machine traveling speed can be easily set to an arbitrary shift position. It can be set reliably, and when the electromagnetic clutch is set to the ON state in the automatic shift mode and the work load becomes heavy, the drive mechanism drives the transmission to decelerate automatically and the engine stops. In the assisted manual shift mode, the traveling load becomes large, such as when turning a ridge, and a large operation reaction force from the hydrostatic continuously variable transmission causes a large operation reaction force from the operation lever. Even if it acts directly on the field, the operating lever can be operated lightly by the driving force of the drive mechanism. In accordance with the state of running can be operated with good gear shifting operation to the appropriate shift position, yet allowed the smooth running and prevent problems engine stop or the like.

According to the second aspect of the invention, the driver does not need to switch to the assist manual shift mode each time when starting a ridge turn when the traveling load increases, thus improving workability and handleability. be able to.

[0015]

Embodiments will be described below with reference to the drawings. FIG.
As shown in, the power of the mounted engine E is supplied to the threshing device 1 and the mowing device 2, and is also supplied to the left and right crawler traveling devices 5 via the hydrostatic stepless transmission 3 and the mission case 4. The traveling control system of the combine is configured so that the harvesting and threshing work can be performed while the aircraft is traveling.

More specifically, the gear shift operation tool 8 and the manual operation lever 7 of the hydrostatic continuously variable transmission 3 are integrally rotatably provided via a rotary support shaft 9 supporting both of them to enable interlocked operation. An electric motor 10 with a speed reducer that cooperates with each other to automatically operate the speed change operation tool 8 via a friction holding mechanism 12 formed of a friction plate.
An example of a drive mechanism is provided so that the electric motor 1 can be operated based on the work situation regardless of the operation position of the manual operation lever 7.
The automatic operation control means A for automatically operating 0 is provided, and the manual operation lever 7 and the electric motor 10 are linked through the electromagnetic clutch 11 which is controlled by the clutch control means C so that the manual operation lever 7 moves forward and backward. A pair of pressure-sensitive switches SW1 and SW2 [an example of a detection unit] for detecting that the pressure-sensitive switches SW1 and SW2 are operated are provided.
Manual shift control means B for driving and controlling the electric motor 10 in accordance with the operating direction of the manual operating lever 7 is provided on the basis of the detection information from.

The electric motor 10 is connected to one end of the rotary support shaft 9, and the friction holding mechanism 12 and the electromagnetic clutch 11 are arranged on the rotary support shaft 9 between the manual operation lever 7 and the electric motor 10. Is installed in series. As for the manual operation lever 7 and the pair of pressure-sensitive switches SW1 and SW2, as shown in FIG. 2, the rotation support shaft 9 is laterally provided at a bent portion of an L-shaped link member 13 having a hollow portion at one end side. And the L-shaped link member 13 is supported by the rotation support shaft 9 so as to be integrally rotatable around the bending axis.
The proximal end portion of the manual operation lever 7 is inserted into the hollow portion of the above, and a fitting hole portion formed in the proximal end portion is rotatably fitted onto the rotary support shaft 9. The pair of pressure sensitive switches SW1 and SW2
Is an inner peripheral portion of the hollow portion of the L-shaped link member 13 on the opening side, and a gap is formed between the base end portion of the manual operation lever 7 and the base end portion of the manual operation lever 7 on both sides in the rotation direction. It is installed separately for each condition. Also, a pair of pressure sensitive switches SW1,
A pair of return springs 14 are separately provided on the inner side of the hollow portion with respect to SW2, and the manual operation lever 7 is attached to both return springs 14 so that there is a space between both the pressure sensitive switches SW1 and SW2. It is vigorous. Further, it is possible to prevent a pressure higher than a set pressure from being applied to the pressure sensitive switches SW1 and SW2 on the inner side of the hollow portion with respect to the pair of return springs 14, and the rotation around the rotation support shaft 9 of the manual operation lever 7 can be prevented. A pair of stoppers 16 for rotating the L-shaped link member 13 integrally with the manual operation lever 7 in association with the rotation are provided.

In the above traveling control system, the clutch control means C is configured so that the electromagnetic clutch 11 can be turned on and off based on the detection information from the pressure sensitive switches SW1 and SW2, and the detection information from the pressure sensitive switches SW1 and SW2. Based on the above, the electromagnetic clutch 11 is set to the disengaged state, and the manual operation lever 7 in the state in which the friction holding by the friction type holding mechanism 12 is released can be operated to shift the speed change operation tool 8 by a manual shift mode, and the electromagnetic clutch 11 is set to the on state, and the electromagnetic clutch 1 is set based on the automatic shift mode in which the automatic shift control means A automatically operates the electric motor 10 and the detection information.
1 is set to the ON state, and the shift mode can be switched to the assisted manual shift mode in which the electric motor 10 is driven corresponding to the operating direction of the manual operation lever 7.

That is, when the manual operation lever 7 is operated from the neutral position in either the forward or backward direction to press one of the pressure sensitive switches SW1 and SW2, the pressure sensitive switch SW
While the SW1 and SW2 are in operation, the clutch control means C sets the electromagnetic clutch 11 to the disengaged state based on the pressure detection information, and the gear shift operation tool 8 is rotated by interlocking with the manual operation lever 7 to be arbitrarily operated. The gear is operated to the position and the manual operation lever 7
Pressure switch SW
When the pressing of the SW1 and the SW2 is released, the electromagnetic clutch 11 is engaged at that position based on the detection information of the pressing release, and the frictional holding mechanism 12 acts so that the position is held even if the hand is released from the manual operation lever 7. In addition, the shift operation is possible in the manual shift mode.

The automatic shift control means A is provided in the control device 15 in the form of a control program so that the electric motor 10 is controlled and driven by the control device 15 equipped with a microcomputer so that the load on the engine E exceeds a set value. And is configured to automatically perform deceleration operation.

That is, the engine E is provided with a rotation speed detection sensor S1 for detecting the rotation speed thereof, and the vehicle speed detection sensor for detecting the vehicle speed based on the output rotation speed of the auxiliary transmission 6 installed in the mission case 4. S2 is provided and the outputs of the detection sensors S1 and S2 are provided to the control device 15. Since the engine E is set to the full accelerator state during the work, the control device 15 determines that the engine load becomes the set value or more when the engine speed becomes the set value or less, and automatically sets the vehicle speed to the preset vehicle speed. The electric motor 10 is drive-controlled so as to decelerate mechanically.

The pressure sensitive switches SW1 and SW2
The electromagnetic clutch 11 is set to the engaged state based on the detection information of 1., and the manual shift control means B for driving and controlling the electric motor 10 in the operation direction side is controlled in preference to the control operation of the automatic steering control means A. A program format is provided so that the shift operation can be performed in the assist manual shift mode. The outputs of the pressure sensitive switches SW1 and SW2 are the control device 1
5, while the pressure sensitive switches SW1 and SW2 are operating, the control device 15 drives and rotates the electric motor 10 in the lever operating direction side, and when the lever operation is stopped, the pressure applied to the pressure sensitive switches SW1 and SW2. Then, the pressure sensitive switches SW1 and SW2 are deactivated and the electric motor 10 is stopped. In this way, the lever can be operated with a small operating force.

As shown in FIG. 1, in the above control system,
The shift mode switching means D is provided for the automatic shift control means A, the manual shift control means B and the clutch control means C in a control program format and an automatic / manual changeover switch type. Then, a turning detection sensor S3 of the airframe is provided,
When the vehicle speed detection sensor S2 detects a low speed value smaller than the set value and the turning detection sensor S3 detects the turning state of the machine body, the shift mode is automatically changed to the assist manual shift mode based on both detection information. The shift mode switching means D is configured to switch to.

Therefore, even if the traveling load becomes large and a large operation reaction force from the hydrostatic stepless transmission 3 directly acts on the operation lever 7 as when turning the ridge, the electric motor 10 The operating force of the operating lever 7 can be lightly operated by the driving force of the. When the operation lever 7 is stopped at an arbitrary shift position, the manual shift control is stopped based on the detection information from the pressure sensitive switches SW1 and SW2.
The vehicle travels at a speed corresponding to the shift position. As described above, when the ridge is turned, the shift mode is automatically switched to the assist manual shift mode.Therefore, it is not necessary for the driver to switch to the assist manual shift mode when turning the ridge. Can be omitted.

[Other Embodiments] The shift mode switching means D is configured by providing a three-position switching type manual switch which is selectively operated by the driver in the manual shift mode, the automatic shift mode, and the assist manual shift mode. May be.

The gear shifting operation in the assisted manual gear shifting mode is not limited to the above-mentioned ridge turning,
For example, it is possible to switch to the assisted manual shift mode when the shift operation is performed at a place where the road surface resistance increases when going straight.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of drawings]

[Fig. 1] Travel control system diagram of combine harvester

[Figure 2] Vertical side view around the manual control lever

[Explanation of symbols]

 3 continuously variable transmission 7 manual operation lever 8 speed change operation tool 10 drive mechanism 12 friction holding mechanism A automatic speed change control means B manual speed change control means C clutch control means D speed change mode switching means SW1, SW2 detection section S2 vehicle speed detection sensor S3 machine body Turn detection sensor

Claims (2)

[Claims] 1. A hydrostatic continuously variable transmission (3) is linked with a gear shift operating tool (8) and a manual operating lever (7) in an interlocking manner, and the gear shift operating tool (8) is frictionally held. A drive mechanism (10) that is automatically operated via a mechanism (12) is provided, and automatic shift control that automatically operates the drive mechanism (10) based on the work situation regardless of the operation position of the manual operation lever (7). Means (A) is provided, and the manual operation lever (7) and the drive mechanism (10) are linked through an electromagnetic clutch (11) which is controlled to be turned on and off by the clutch control means (C), and the manual operation lever is connected. A detection unit (SW1) for detecting that (7) is operated in either forward or backward direction,
(SW2) is provided, and the detection units (SW1) and (SW2) are provided.
The drive mechanism (10) based on the detection information from
A shift operation structure for a work vehicle, comprising: a manual shift control means (B) for performing drive control corresponding to an operation direction of the manual operation lever (7), wherein the clutch control means (C) is the detection part ( SW1),
On / off control of the electromagnetic clutch (11) is possible based on the detection information from (SW2), and based on the detection information, the electromagnetic clutch (11) is set to the disengaged state to perform the friction holding. The manual operation lever (7) in a state where the friction holding by the mechanism (12) is released is set to a manual speed change mode in which the speed change operation tool (8) can be operated to change the speed, and the electromagnetic clutch (11) is set to the on state. An automatic shift mode in which the automatic shift control means (A) automatically operates the drive mechanism (10), and the electromagnetic clutch (11) is set to an on-state based on the detection information, and the drive mechanism (10) is a shift mode switching means (D) for switching the shift mode to an assisted manual shift mode in which the manual operation lever (7) is driven corresponding to the operating direction, and the automatic shift control means (A). Speed change operation structure of the working vehicle is provided with respect to the dynamic shift control means (B) and clutch control means and (C). 2. A vehicle speed detection sensor (S2) and a vehicle body turning detection sensor (S3) are provided, and the vehicle speed detection sensor (S2) is provided.
Detects a value smaller than the set value and the turning detection sensor (S3) detects the turning state of the machine body, the shift mode is automatically switched to the assist manual shift mode based on both detection information. The shift operation structure for a work vehicle according to claim 1, wherein the shift mode switching means (D) is configured as described above.