JP2004190636A - Tractor engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with circuit design for each of models and reduce the cost by commonly using a main part of an electric circuit with respect to the models having different conditions. <P>SOLUTION: A controller is constituted so that seating detection is one of engine start conditions and an engine is automatically stopped based on seat leaving detection after start of the engine, and an AND condition that detection that a PTO system is non-transmitting state and detection that a traveling system is in the neutral state has an equivalent relation with the seating detection of the controller. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention has a function of automatically stopping the engine when it is detected that the driver has left the driver's seat, and the aircraft may run away due to erroneous operation while the driver is away from the driver's seat. The present invention relates to an engine control device for a tractor that is configured not to have the same.
[0002]
[Prior art]
Conventionally, tractors with functions include a seat switch that detects the driver's absence, a neutral switch that detects that the traveling system is neutral, and a parking brake that detects that the parking brake of the vehicle body is locked. A switch and a seat lock switch that can be manually set by the driver are provided.When the driver leaves the seat, the seat lock switch is set and operated so that the engine can be operated even when the driver is away. There is a configuration in which the PTO shaft can be driven while driving continuously (see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Publication No. 8-6615
[Problems to be solved by the invention]
The above-mentioned conventional means is provided with a dedicated electric circuit for automatically stopping the engine when a predetermined condition is satisfied, and cannot be directly applied to a model having different condition specifications. The circuit must be designed, which contributes to high costs.
[0005]
The present invention has been made in view of such a point, and it is not necessary to design a circuit for each model by enabling a main part of an electric circuit to be shared for models having different specifications of conditions. The main purpose is to reduce costs.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following configuration.
[0007]
The invention according to claim 1 includes a controller configured to set the seating detection as one of the engine start conditions and to automatically stop the engine based on the unattended state detection after the engine start,
The AND condition between the detection that the PTO system is in the non-transmission state and the detection that the traveling system is in a neutral state is configured to be equivalent to the seating detection in the controller.
[0008]
According to this configuration, the detection of the PTO system in the non-transmission state and the detection of the neutrality of the traveling system do not have an AND condition, so that the seating detection is performed as one of the engine starting conditions. An engine control device having the following specifications can be configured. Also, by adopting a configuration having an AND condition for detecting that the traveling system is in a neutral state, the satisfaction of the AND condition is one of the engine starting conditions. As a result, an engine control device having a specification in which the seating detection is excluded from the engine starting conditions can be configured.
[0009]
The invention according to claim 2 includes a controller configured to set the seating detection as one of the engine start conditions, and to automatically stop the engine based on the unattended state detection after the engine start,
A seat switch which is closed by the detection of seating and opened by the detection of absence from the seat is connected to one of the condition input ports of the controller on the high side, and when an "H" signal is applied to the condition input port, the engine operation is continued, The controller is configured so that the engine is automatically stopped when an “L” signal is applied to the condition input port, and closes when the PTO system is in a non-transmission state to another condition input port of the controller. A PTO switch that opens when the PTO system is in the transmission state and a running switch that closes in the neutral state and opens in the running state are connected in series on the high side, and a branch circuit derived from a circuit portion connecting the PTO switch and the running switch. Is connected to the condition input port for the absence detection, and the condition input port is connected to this branch circuit. Characterized in that the current flow direction are interposed the diode to forward to.
[0010]
According to this configuration, by connecting only the seat switch to the condition input port for the unattended state detection, it is possible to configure an engine control device having a specification in which the seating detection is one of the engine starting conditions, and With the configuration in which the seat switch and the branch circuit are connected in parallel to the condition input port for detection, even if the seat switch is not closed, the engine starts as long as the "H" signal is applied to the branch circuit. When one of the conditions is satisfied, an engine control device having a specification in which the seating detection is excluded from the engine start condition can be configured.
[0011]
Therefore, according to the present invention, the same controller can be shared by engine control devices having different engine start conditions, and cost can be reduced as compared with a case where a dedicated engine control device circuit is designed for each specification. In addition, the development time can be reduced.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an example of a tractor having an automatic engine stop function. The tractor of this example is configured so that a hydraulic excavator 2 is attached to the rear of the tractor 1 as an example of an attached working device, and a transmission system diagram of the tractor 1 is shown in FIG. Have been.
[0013]
That is, the power of the engine 3 mounted on the front part of the fuselage is transmitted to the main transmission 5 composed of a hydraulic continuously variable transmission (HST) via the main clutch 4, and the transmission power from the main transmission 5 is further increased. After being shifted by the gear type auxiliary transmission 7 in the transmission case 6, the transmission is transmitted to the rear wheels 8 and the front wheels 9. A part of the engine power input to the main transmission 5 is shifted by the PTO transmission mechanism 10 and then transmitted to the rear PTO shaft 12 at the rear of the fuselage via the PTO clutch 11 and the mid PTO clutch 13 The power is also transmitted to the mid-PTO shaft 14 in the middle part of the fuselage. The hydraulic unit 15 provided in the excavator 2 is driven by power from the rear PTO shaft 12.
[0014]
As shown in FIGS. 3 to 5, an unattended state detecting device 17 is provided below the driver's seat 16 provided in the tractor main body 1. The unattended state detecting device 17 electrically detects whether the vehicle is in the seated state or the unseated state based on the presence or absence of a seating load on the driver's seat 16. When the unseated state is detected under predetermined conditions, the engine (diesel) is detected. The engine 3 is automatically stopped.
[0015]
FIG. 6 shows an electric circuit diagram for automatically stopping the engine 3 based on the absence detection. In the figure, reference numeral 20 denotes a controller constituted by using a microcomputer, 21 denotes a main switch composed of a key switch, 22 denotes a cell motor for starting the engine, 23 denotes a motor starting relay, 24 denotes a fuel cut valve, and 25 denotes an energized excitation. A solenoid that opens the fuel cut valve 24, 26 is a solenoid relay, 27 is a glow plug for warming up the engine, and 28 is a glow lamp for monitoring. SW1 is a main clutch switch that closes (ON) when the main clutch pedal (not shown) is depressed and the main clutch 4 is disengaged, and SW2 is closed (ON) when the main transmission 5 is in neutral. A traveling switch, SW3 is a PTO switch that is closed (ON) when the PTO clutch 11 is disengaged, SW4 is a mid PTO switch that is closed (ON) when the mid PTO clutch 13 is disengaged, and SW5 is A seat switch (see FIG. 4) that is closed (ON) by receiving a sitting load on the driver seat 16 (see FIG. 4), a PTO release switch (see FIG. 5) that closes (ON) when the driver seat 3 is turned forward, D1 and D2 are diodes, and switches SW1 to SW6 are connected to three condition input ports p1, p2, and p3 provided in the controller 20, respectively. Which it is connected as.
[0016]
The three condition input ports p1, p2, and p3 are connected to the accessory terminal of the main switch 21 in parallel on the high side via circuits a, b, and c, respectively, and are connected to the first condition input port p1. a, the traveling switch SW2, the PTO switch SW3, and the mid-PTO switch SW4 are interposed in series in the circuit c connected to the third condition input port p3. The PTO release switch SW6 is connected to a bypass circuit d provided in parallel with the switch SW3.
[0017]
Further, a branch circuit e extending from a circuit portion connecting the PTO switch SW3 and the mid PTO switch SW4 is connected to the circuit a below the seat switch SW5, and the branch circuit e is connected to the circuit a from the circuit c. The diode D1 is interposed with the current flowing direction to the forward direction. The diode D2 is provided between the branch point of the branch circuit e and the connection point of the bypass circuit d. When the PTO release switch SW6 is closed, the current passing through the bypass circuit d is supplied to the branch circuit e. It is designed to prevent it from flowing.
[0018]
Here, when the “H” signal is applied to all of the condition input ports p1, p2, and p3, the outputs of the output ports p4 and p5 become “H”, respectively, and the “H” signal is output to the condition input port p2. When an "H" signal is applied to the condition input port p1 or p3, the output of the output port p4 is maintained at "H", and an "L" signal is applied to both the condition input ports p1 and p3. And the controller 20 is programmed so that the output of the output port p4 becomes "L". Next, the engine start operation and the engine automatic stop control using the above circuit will be described.
[0019]
When the main transmission is set to neutral, the travel switch SW2 is turned "ON", the PTO switch SW3 is turned "ON", the mid PTO switch SW4 is turned "ON", and the main switch 21 is operated to the engine start position ST, a condition input is performed. Since the "H" signal is applied to all of the ports p1, p2, and p3, the outputs of the output ports p4 and p5 both become "H", the solenoid relay 26 is closed, and the solenoid 25 is energized. The fuel cut valve 24 is opened, and fuel can be supplied to the engine 4. Here, when the main clutch switch SW1 is turned “ON” by depressing the main clutch pedal, the relay 23 is closed and the starter motor 22 is energized, and the engine 4 is started. In this case, the seat switch SW5 and the PTO release switch SW6 are not involved in the engine start, and the engine start conditions are shown in FIG.
[0020]
After confirming that the engine 4 has been started, the main switch 21 is returned to the accessory position AC, and when the main clutch pedal is released, the main clutch switch SW1 is turned off, but the condition input ports p1, p2, Since the signal application condition to p3 does not change, the output of output port p4 is maintained at "H", the fuel supply state is continued, and engine 4 is maintained in the operating state. That is, in a state where the driving is stopped and the driving rotation of the rear PTO shaft 12 and the mid PTO shaft 14 is stopped, the engine 4 continues to operate even if the driver leaves the aircraft.
[0021]
After the engine 4 is started, when the driver sits on the driver's seat 16 and travels, the travel switch SW2 is turned “OFF” and the signal applied to the condition input port p3 becomes “L”. Since the seat switch SW5 is turned “ON” by sitting on the seat 16 and the applied signal to the condition input port p1 is “H”, the output from the output port p4 is maintained at “H”, and the fuel supply is performed. The state is continued, and the engine 4 is maintained in the operating state. In this case, the PTO switch SW3 and the mid PTO switch SW4 have no relation to the automatic engine stop.
[0022]
If the main transmission 5 is accidentally removed from neutral while the driver is away from the seat, the seat switch SW5 is turned "OFF" and the signals applied to the condition input ports p1 and p2 are both "L". , The output of the output port p4 is switched to "L", the solenoid relay 26 is opened, the energization of the solenoid 25 is cut off, the fuel cut valve 24 is closed, and the engine 4 is stopped.
[0023]
Even if the traveling is stopped and the traveling switch SW2 is turned “ON”, at least one of the PTO clutch 11 and the mid PTO clutch 13 is engaged, and at least one of the PTO switch SW3 and the mid PTO switch SW4 is turned “OFF”. When the driver leaves the seat in a state where the vehicle is in the state, the seat switch SW5 is turned "OFF" and the signals applied to the condition input ports p1 and p2 are both "L", so that the output of the output port p4 is switched to "L". Then, the solenoid relay 26 is opened, the energization of the solenoid 25 is cut off, the fuel cut valve 24 is closed, and the engine 4 is stopped.
[0024]
In this case, if the PTO release switch SW6 is switched to "ON", traveling can be stopped (the traveling switch SW2 is "ON"), and the mid-PTO clutch 13 can be disengaged (the mid-PTO switch SW4 is "ON"). For example, even when the PTO clutch 11 is engaged and the PTO switch SW3 is turned "OFF", the signal applied to the condition input port p3 is maintained at "H". In this state, the driver's seat 16 is vacant. As a result, even if the seat switch SW5 becomes "0FF" and the signal applied to the condition input port p1 becomes "L", the operating state of the engine 4 is maintained. That is, if the PTO release switch SW6 is set to "ON", the hydraulic unit 15 of the excavator 2 can be driven by the rear PTO shaft 12 even when the user is away from the seat, and the excavation work can be performed at a fixed position. You can.
[0025]
Here, FIG. 7B shows a chart of the conditions under which the engine automatic stop is executed.
[0026]
FIG. 9 shows an example of a mounting structure of the PT0 switch SW3 and the mid PTO switch SW4. As shown in the figure, a PTO turning-off lever 30 and a mid PTO turning-off lever 31 are provided so as to be able to swing back and forth around a common fulcrum x at the upper part of the transmission case, and are provided on these levers 30, 31 and the side of the transmission case 6. The PT0 operating arm 32 and the mid-PTO operating arm 33 are linked by operating rods 34 and 35, respectively, and a mid-PTO switch SW4 and a PT0 switch SW3 are attached to two upper and lower positions of the operating rod 35 of the mid-PTO system. Have been.
[0027]
As shown, when the mid-PTO on / off lever 31 is operated forward to operate the mid-PTO operation arm 33 to the clutch disengagement position, the mid-PTO switch SW4 also moves downward integrally with the operation rod 35 which moves downward. The mid PTO switch SW4 is pressed by the rib 6a to be closed (ON) relative to the rib 6a protruding from the outer surface of the transmission case 6. When the PTO on / off lever 30 is operated forward to operate the PTO operation arm 32 to the clutch off position in a state where the mid PTO on / off lever 31 is operated forward, the operation piece 32a extending from the PT0 operation arm 32 is moved. When the PT0 switch SW3 is pressed from below, the PT0 switch SW3 is closed (ON).
[0028]
When the mid-PTO on / off lever 31 is operated backward to operate the mid-PTO operation arm 33 to the clutch engagement position, the mid-PTO switch SW4 also moves upward together with the operation rod 35 moving upward and separates from the rib 6a. , The mid-PTO switch SW4 is opened (OFF). Further, when the mid-PTO on / off lever 31 is operated backward, the PTO switch SW3 is largely retracted upward, so that the PT0 switch SW3 is kept open (OFF) regardless of the operating position of the PTO on / off lever 30.
[0029]
The controller 20 can be used as an engine control device in a tractor for a lawnmower with the following specifications.
[0030]
In this example, the three condition input ports p1, p2, and p3 provided in the controller 20 are closed (ON) when the seat switch SW5 that closes (ON) in a seated state and the brake pedal is depressed to the braking position. Brake switch SW7 and a PTO switch SW8 that closes (ON) when the drive of the mower drive mid-PTO shaft is stopped are connected to the high side, respectively, and the fuel cut solenoid 25 is connected to the output ports p4 and p5. Cell motors 22 are connected respectively.
[0031]
The engine start and the engine automatic stop control are performed according to the signal input state to the condition input ports p1, p2, and p3 of the controller 20, and according to the operation states of the seat switch SW5, the brake switch SW7, and the PTO switch SW8. Thus, the engine start and the engine automatic stop control are performed, and the operating conditions are shown in FIG.
[0032]
That is, in the tractor for a lawnmower, the brake is operated (the brake switch SW7 is turned on) while the driver is seated (the seat switch SW5 is turned on), and the driving of the mid-PTO shaft is stopped. (The PTO switch SW8 is turned on) is set as the engine start condition, and in a state where the mid-PTO shaft is driven and the mower is operating, the engine is automatically stopped when the absence of the seat is detected, Even when the mid-PTO shaft is stopped, the engine is automatically stopped if the driver leaves the seat without applying the brake.
[Brief description of the drawings]
FIG. 1 is an overall side view of a tractor. FIG. 2 is a transmission system diagram. FIG. 3 is a side view showing a leaving state of a leaving detecting mechanism. FIG. 4 is a side view showing a sitting state of a leaving detecting mechanism. FIG. 6 is a side view showing the seat reversal state of the unattended state detection mechanism. FIG. 6 is an electric circuit diagram of the automatic engine stop device. FIG. 7 is a diagram showing (a) an engine start condition. 8 is a side view showing a switch mounting structure. FIG. 9 is an electric circuit diagram of another application example. FIG. 10 is a chart showing engine start and engine automatic stop conditions in another application example.
3 Engine 20 Controller SW2 Run switch SW3 PTO switch SW5 Seat switch D1 Diode

Claims (2)

A controller configured to make the seating detection one of the engine start conditions and to automatically stop the engine based on the unattended detection after the engine start,
A tractor characterized in that the AND conditions for detecting that the PTO system is in the non-transmission state and detecting that the traveling system is neutral are equivalent to the seating detection in the controller. Engine control device. A controller configured to make the seating detection one of the engine start conditions and to automatically stop the engine based on the unattended detection after the engine start,
A seat switch which is closed by the detection of seating and opened by the detection of absence from the seat is connected to one of the condition input ports of the controller on the high side, and when an "H" signal is applied to the condition input port, the engine operation is continued, The controller is configured so that the engine is automatically stopped when an “L” signal is applied to the condition input port, and closes when the PTO system is in a non-transmission state to another condition input port of the controller. A PTO switch that opens when the PTO system is in the transmission state and a running switch that closes in the neutral state and opens in the running state are connected in series on the high side, and a branch circuit derived from a circuit portion connecting the PTO switch and the running switch. Is connected to the condition input port for the absence detection, and the condition input port is connected to this branch circuit. Tractor engine control device, characterized in that the current flow direction are interposed the diode to forward to.

Images