JP2007092877A - Clutch control system of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to disconnect a clutch adequately by detecting the operating position of a clutch pedal accurately, while it makes to possible to input the clutch pedal stepping-on amount to the control means by detecting the clutch pedal stepping accurately for securing the safety performance of running and working by controlling the clutch operation on the way of the route to transmit the output rotation power from an engine to the transmission mechanism on the right side of the drive transmission. <P>SOLUTION: It constitutes the clutch pedal 3 to switch on a clutch 2, a magnetic control valve 4, the potentiometer type first sensor 5 to detect the stepping-on amount of the clutch pedal 3 and the switch type second sensor 6 to detect the stepping-on operation. In this case, the control means 7 which operates to cut off the clutch 2 is provided by the input signal of the first sensor 5 or the second sensor 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a first sensor that detects a depression amount of the clutch pedal and a switch-type second sensor that detects a depression operation of the clutch pedal, and one of the sensors determines the clutch disengagement position of the clutch pedal. When detected, the present invention relates to a clutch operating device for a work vehicle provided with a control means for operating to disengage the clutch.

  A clutch equipped in a recent work vehicle or the like has a configuration in which an on / off control operation is performed by a control means including a microcomputer based on a depression amount of a clutch pedal. The control means detects the amount of depression of the clutch pedal (depression stroke) using a potentiometer type sensor, and controls the on / off of the clutch based on the detected value. In this case, the control means outputs a control signal to an output-side actuator, that is, an electromagnetic proportional flow control valve, based on the input detection signal, switches, discharges the hydraulic oil, releases the hydraulic pressure, and returns to the return spring. In general, a mechanism for returning the hydraulic piston to disengage the clutch by the action of.

  In this way, the control means disengages the clutch in response to the depression operation of the clutch pedal, and interrupts the transmission of the rotational power, but it is important to disengage the clutch accurately at the correct position. This is a necessary condition for ensuring safety.

In the publicly known Japanese Patent Application Laid-Open No. 7-127666, a clutch pedal, a potentiometer-type pedal sensor, a control device, an electromagnetic proportional flow control valve, and a main clutch are electrically connected with a focus on the control device. In addition, a clutch operation control mechanism is disclosed in which the main clutch is disengaged and the transmission of the rotational power is interrupted by connecting a hydraulic circuit and depressing the clutch pedal.
JP-A-7-127666

  This type of main clutch is provided in the middle of the path where the rotational power output from the engine is transmitted to the transmission mechanism on the lower transmission side, and finally controls the rotational power that becomes the driving power for the driving power and work equipment. It is configured to be intermittently operated by means. In such clutch operation control, it is very important to accurately detect the amount of operation of the clutch pedal and input it to the control means in order to ensure the safety of traveling and work. Therefore, the above-described conventionally known clutch has a configuration in which the amount of depression of the clutch pedal is detected by a single potentiometer type pedal sensor, and the control means performs the clutch disengagement operation based on the detection result. Since there is a single sensor, if detection failure or abnormality occurs and accurate detection cannot be performed, there is a problem that the safety of traveling and the safety of work are greatly impaired.

  In order to solve the above-mentioned problem, the present application provides a clutch pedal (3) for turning on and off a clutch (2) of a vehicle (1), and turning on and off the clutch (2). An electromagnetic control valve (4) to be operated, a potentiometer type first sensor (5) for detecting the depression amount of the clutch pedal (3), and a switch type second sensor (6) for detecting the depression operation. And a control means (7) for operating the clutch (2) when the first sensor (5) detects a predetermined depression amount or when the input signal of the second sensor (6) is switched. A clutch operating device for a work vehicle, two systems of a potentiometer-type first sensor (5) for detecting the depression amount of the clutch pedal (3) and a switch-type second sensor (6) for detecting the depression operation Sensors (5) (6) It has been with the provided configuration.

  Thus, according to the first aspect of the present invention, the clutch pedal operation amount (operation stroke) and the operation position are determined by the two systems of the first sensor (5) and the second sensor (6) having different detection characteristics. Since the control for disengaging the clutch (2) is performed by detecting either one of the sensors (5) or (6), the safety of traveling and work can be ensured. .

  Next, in the invention described in claim 2, a dead zone (B) is set in the detection range of the clutch disengagement detection position (A) of the first sensor (5), and the pedal is located outside the dead zone of the dead zone (B). When the detection value of the second sensor (6) detects the depression state of the pedal (3) on the small depression amount side, or out of the dead zone (B) and on the large pedal depression amount side, The control means (7) according to claim 1, further comprising a control means (7) for notifying an abnormality when a detected value of the second sensor (6) detects a non-depressed state of the pedal (3). It is a clutch operating device for a work vehicle. Originally, the switch sensor (6) may have a different operating position between a position that changes from ON to OFF and a position that changes from OFF to ON. A slightly different position, but dead zone B) abnormality determination by providing the zones has the advantage of easier.

  First, according to the present invention, the operation amount and the operation position of the clutch pedal (3) are detected by two systems of the potentiometer type first sensor (5) and the switch type second sensor (6). And a control means (7) having a double safety mechanism for disengaging the clutch (2) by detecting one of the sensors (5) or (6). The clutch (2) disengagement operation is accurately performed by accurately detecting the operation position of the clutch pedal (3), and the safety of running and work can be greatly improved. .

  The invention described in claim 2 is characterized by facilitating judgment when abnormality occurs in the sensors (5) and (6). Originally, the switch sensor (6) may have a different operating position from ON to OFF, or from OFF to ON, and the operating point may be slightly shifted with each operation, but a dead zone (B) zone should be provided. There is a feature that makes it easy to judge abnormalities.

  In the first aspect of the invention, when the clutch 2 of the tractor 1 is turned on and off, a potentiometer-type first sensor 5 for detecting the depression amount of the clutch pedal 3 and an ON / OFF switching switch for detecting the depression operation. The second sensor 6 is provided, and when either one of the sensors 5 or 6 detects the disengagement position of the clutch 2, it is provided with control means 7 for operating the clutch 2 to disengage, This is an invention in which a double safety mechanism using sensors 5 and 6 having different detection contents is configured to further improve the safety of traveling and the safety of work.

  The invention according to claim 2 sets the dead zone B in the detection range of the disengagement detection position of the clutch 2 of the first sensor 5, and outside the dead zone B and on the side where the amount of depression of the pedal 3 is small, When the detection value of the second sensor 6 detects the depression state of the pedal 3, or outside the dead zone B and on the large depression amount side of the pedal 3, the detection value of the second sensor 6 is the non-depression of the pedal 3. The control means 7 for notifying abnormality when detecting the depressed state is provided, so that the abnormality of the sensor can be easily determined.

Embodiments of the present invention will be specifically described below with reference to the drawings.
First, the tractor 1 corresponds to the vehicle 1 of the present application. As shown in FIG. 6, a cabin 10 is mounted on a vehicle body 1 a, and a control seat and a driving operation device are installed in the cabin 10. Are arranged in a concentrated manner, and on the front side, a steering handle 11 is mounted on the upper portion of the handle post 12 so that the front wheels 13, 13 can be steered with a light operating force via a power steering mechanism (not shown). As shown in the drawing, the display / operation panel 15 is provided with a speed display meter at the center position in the cabin 10, and various display units, operation dials, and operation switches are arranged around the center. In this configuration, the steering handle 11 is mounted at an easily visible position in front of the steering handle 11. As shown in FIG. 6, the forward / reverse switching lever 16 is provided at the upper part of the handle post 12 and the clutch pedal 3 is provided at a lower position thereof.

  As shown in FIG. 6, the engine 17 is housed and mounted at the front of the vehicle body 1a, in front of the cabin 10, below the hood cover 18 that can be freely opened and closed, and provided at the lower rear. It is set as the structure which transmits rotational power to the traveling mission apparatus 19 currently provided. As shown in FIGS. 2 and 6, the traveling mission device 19 includes a forward / reverse switching device 22 and a main transmission 23 that are conventionally installed in the tractor 1 inside the mission case 20. And the auxiliary transmission device 24 are arranged in this order, and the rotational power shifted to the rear wheels 25 and 25 and the PTO shaft 26 is output. In this embodiment, as shown in FIG. 2, the clutch 2 corresponds to the forward / reverse hydraulic clutch provided in the forward / reverse switching device 22 and is located on the upper transmission side of the traveling mission device 19. The main clutch function is used.

  As shown in FIGS. 2 and 6, the clutch pedal 3 is positioned closer to the side portion below the handle post 12 in the cabin 10, and the base P of the pedal arm 3 a is moved. The clutch 2 is pivotally attached to the airframe 27, and the clutch 2 is disengaged by a detection mechanism and a control means 7 to be described later by a stepping operation. As shown in FIG. 2, the return spring 28 is provided between the mounting arm 29 extending from the base P to the front side and the airframe 27, and tension acts in a direction against the stepping, so that the foot from the clutch pedal 3 is lifted. When released, the pedal is returned to its original position before being depressed.

  As shown in FIG. 2, the first sensor 5 is a potentiometer-type sensor, and the detection arm 31 of the sensor is engaged with the operating arm 30 extended upward from the base P of the pedal arm 3a. The pedal arm 3a can be detected by detecting the amount of depression of the pedal arm 3a (meaning “full stroke”, the same applies hereinafter). As shown in FIG. 1, the first sensor 5 is configured so as to detect the depression amount of the clutch pedal 3 as described above and to input detection information to the control means 7.

  Next, as shown in FIG. 2, the second sensor 6 is a switch type sensor that switches between ON and OFF, and is provided at the depression position on the lower side of the base portion of the pedal arm 3 a that is rotated by a depression operation. It is configured to switch at the clutch disengagement position. As shown in FIG. 1, the second sensor 6 is configured to detect the depression position of the clutch pedal 3 and to connect the detection information to the control means 7.

  Thus, as shown in FIG. 1, the control means 7 connects the first sensor 5 and the second sensor 6 to the input side, connects the electromagnetic control valve 4 to the output side, and detects the input. Based on the information, a control signal is output and the clutch 2 is turned on and off. Then, the control means 7 of the embodiment outputs a control signal to the electromagnetic control valve 4 when the first sensor 5 detects a predetermined depression amount or when the input signal of the second sensor 6 is switched. It is set as the structure which operates 2 off.

  As shown in FIG. 1, the control means 7 has a forward clutch pressure sensor 33, a reverse clutch pressure sensor 34, a main transmission 1 clutch pressure sensor 35, a main transmission 2 clutch pressure sensor 36, a main transmission 3 clutch pressure on the input side. A sensor 37, a main transmission 4-clutch pressure sensor 38, a sub-transmission H clutch pressure sensor 39, and a sub-transmission L clutch pressure sensor 40 are connected to each other so that a shift operation signal can be input.

  And the solenoid valve which electromagnetically switches each oil path is connected to the control means 7 at the output side. That is, as shown in FIG. 1, the control means 7 includes, on the output side, a forward solenoid 42, a reverse solenoid 43, a main transmission 1 solenoid 44, a main transmission 2 solenoid 45, a main transmission 3 solenoid 46, a main transmission 4 solenoid 47, The sub-transmission H solenoid 48 and the sub-transmission L solenoid 49 are connected to each other so that the shift control can be performed by electromagnetically switching the valve based on the control signal.

  In the case of the above-described embodiment, the main transmission 23 is configured to be capable of shifting in four stages from the first speed to the fourth speed, and the auxiliary transmission 24 is in two stages of high speed (road speed on the road) and low speed (work speed). In this configuration, all of the gears are electromagnetically shifted by a switch operation. In FIG. 1, reference numeral 50 denotes a second auxiliary shift position sensor, and reference numeral 16 denotes a forward / reverse switching lever already described.

  Then, as shown in FIG. 3, the first sensor 5 and the second sensor 6 detect the stepping amount in the process of stepping on the clutch pedal, and when the first sensor 5 reaches the dead band opening side, The control means 7 outputs a control signal and becomes a point at which the change of the hydraulic pressure is started. Further, when the control means 7 is stepped on, it reaches the switch-off position which is the second sensor 6, and then the stepping further proceeds and the first sensor 5 It is configured in a relational position that reaches the cut-off.

With this configuration, the control means 7 enables the clutch 2 to be operated in a half-clutch state by detecting the depression amount by the first sensor 5.
As shown in the graphs of FIGS. 4 and 5, the control pressure and the drive current of the clutch 2 change flatly, and the pressure changes as the clutch pedal 3 moves. The pressure is increased as it goes to the release side. In this way, when the clutch 2 is released from the clutch pedal 3 and reaches the engaged state, the transmission state is continued by increasing the pressure of the hydraulic clutch. On the other hand, as shown in FIG. 5, the drive current is configured to perform an initial output in order to operate the clutch piston as short as possible to the meet point at the start of clutch output.

  The clutch pressure is configured to increase the pressure as it reaches the disengagement side according to the detection of the first sensor 5, and the initial output that operates the clutch piston as short as possible to the meet point by the change of the second sensor 6. You may make it the structure to perform.

If comprised in this way, since an Example performs an initial output at the timing of the signal change which carries out a hardware cut-off operation, stable clutch alignment becomes possible.
Next, in this type of clutch control, it is necessary for safety to correctly and quickly determine sensor abnormality. Hereinafter, a description will be given of abnormality determination and measures for reducing the occurrence of abnormality.

  First, the control means 7 stores in advance at which position of the depression amount detected by the first sensor 5 the switch of the second sensor 6 is switched, and the switch 6 changes in the depression step of the clutch pedal 3. From the detection and the change of the potentiometer 5, even if one detects the stepping position, if the other is not detected, it is determined as abnormal and an alarm is issued.

Thus, since it is necessary to improve the safety of the clutch 2 disengagement operation, when an abnormality occurs, the abnormal state can be notified reliably and quickly.
And the control means 7 forms the dead zone B zone which does not perform abnormality determination before and behind the switch change position of the 2nd sensor 6 memorize | stored in the 1st sensor 5, and performs abnormality determination out of the zone of this dead zone B zone. Examples of construction are conceivable. That is, for example, as shown in FIG. 3, the control means 7 of the embodiment is such that the detection value of the second sensor 6 is in the depression state of the pedal 3 outside the dead zone B zone and on the small pedal depression amount side. Or when the detected value of the second sensor 6 detects a non-depressed state of the pedal 3 outside the zone of the dead zone B and on the large pedal depression amount side. Since it can be determined, it is assumed that a warning is given.

  In particular, as shown in FIG. 3, in the second sensor 6, the operation position from ON to OFF and the operation position from OFF to ON may be different during operation, as shown in FIG. Since the position may be slightly different each time, the significance of providing the dead zone B zone in which no abnormality is determined is significant.

  If comprised as mentioned above, the control means 7 can eliminate the erroneous detection of abnormality determination. At the time of abnormality determination, an alarm is issued to notify the operator, and at the same time, the clutch 2 is automatically turned off to ensure safety. However, in consideration of safety in traveling and work, A system for outputting a control signal for disengaging the clutch 2 with priority over anything is necessary and is adopted in the embodiment.

  In the case of the embodiment, the two systems of sensors 5 and 6 are configured so that the wiring from the detection position to the control means 7 is not connected to a single harness but connected by separate paths, respectively. By doing so, there is an advantage that only one side of the harness can be protected from harm such as rats.

  Furthermore, two sensors 5 and 6 connect the first sensor 5 to the control means 7, and connect the other second sensor 6 to another clutch disconnection circuit without using the control means 7. There is also a method of inputting detection information. If comprised in this way, when the clutch 2 will step on the clutch pedal 3, even if abnormality arises in a series of control means 7 which consists of microcomputers, it will be able to carry out cutting operation by another clutch cutting circuit, A safer device can be provided.

  As described above, according to the first embodiment of the present invention, the operation amount and the operation position of the clutch pedal 3 are determined by the two systems of the potentiometer type first sensor 5 and the switch type second sensor 6. Further, the control means 7 having a double safety mechanism for disengaging the clutch 2 by the detection of either one of the sensors 5 or 6 is provided. The operation position of the clutch pedal 3 is accurately detected and performed accurately, and the safety of traveling and work can be greatly improved.

  The second embodiment according to the present invention facilitates the determination when an abnormality occurs in the sensors 5 and 6. Originally, the switch sensor (6) is switched from ON to OFF or from OFF. The operation position to ON may be different, and the operation point is slightly deviated every time the operation is performed, but there is an advantage that abnormality determination can be easily performed by providing the dead zone B zone.

Block diagram showing the control mechanism Side view of clutch pedal Explanatory diagram showing action in graph form Effect graph Effect graph A side view of a tractor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 1a Car body 2 Clutch 3 Clutch pedal 3a Pedal arm 4 Electromagnetic control valve 5 First sensor 6 Second sensor 7 Control means B Dead zone

Claims (2)

  A clutch pedal (3) for turning on and off the clutch (2) of the vehicle (1), an electromagnetic control valve (4) for turning on and off the clutch (2), and a depression amount of the clutch pedal (3) are detected. A potentiometer-type first sensor (5) and a switch-type second sensor (6) for detecting a depression operation, and when the first sensor (5) detects a predetermined depression amount, or a second A clutch operating device for a work vehicle, comprising control means (7) for operating the clutch (2) disengaged when the input signal of the sensor (6) is switched.   A dead zone B is set in the detection range of the clutch disengagement detection position of the first sensor (5), and the detected value of the second sensor (6) is outside the dead zone (B) and on the small pedal depression amount side. When the pedal depression state of the pedal (3) is detected, or outside the dead zone (B) and on the side where the pedal depression amount is large, the detected value of the second sensor (6) is the non-pedal of the pedal (3). The clutch operating device for a work vehicle according to claim 1, further comprising control means (7) for notifying an abnormality when a stepped-on state is detected.

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