JPS6343247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a hydraulically controlled transmission such as a power shift transmission, a hydrostatic drive, etc.
In addition, we have proposed a completely new traveling type agricultural machine with excellent operability and safety, which is configured to control the oil flow of this transmission using an electric circuit. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a schematic side view of the agricultural machine according to the present invention, where CS represents the console and CP represents the main clutch.
The clutch pedals for engaging and disengaging the MC are shown. The driving force of the engine EG is transmitted to the rear wheel RW via the main clutch MC, the power shift transmission system PS, and the clutch pedal CP.
Transmission is cut off by pressing the button. Of course, the structure may be such that the traveling is performed by crawler belts.

Figure 2 schematically shows the top of the console CS.
F1, F2, F3, RS, and ST are all illuminated switches that move the aircraft forward in 1st, 2nd, and 3rd gears.
F1, F2, F3, RS, or ST is pressed when operating the transmission to drive the vehicle at high speed or reverse, or to stop the vehicle. FIG. 3 is a schematic side view of the clutch pedal CP, which is rotatably supported by the body and is connected to a clutch release fork (not shown). A limit switch LS is disposed in front of the clutch pedal CP, and is activated when the clutch pedal CP is depressed to a position that cuts off the main clutch MC, as shown by the two-dot chain line.

FIG. 4 shows a hydraulic circuit that controls the transmission PS. In the figure, V1, V2, V3, and VR are 3-port 2-position switching type, and VS is a 2-port 2-position switching type free-position electromagnetic directional control valve.
PM is pump, RL is relief valve, CL1, CL
2, CL3, and CLR indicate the hydraulic multi-plate clutch in the transmission PS. The hydraulic circuit constituted by these includes electromagnetic directional control valves V1, V2, and V.
3.One solenoid V11, V2 of each VR
By energizing each of the solenoids V1, V31, and VR1, pressure oil is supplied to the multi-plate clutches CL1, CL2, CL3, and CLR, and the other solenoids V12, V22, V32,
By energizing each VR2, the pressure oil is applied to the pump PM side port of the solenoid directional control valve VS, and the solenoid directional control valve VS is opened by energizing one solenoid VS1, and the pressure oil is applied to the pump PM side port of the solenoid directional control valve VS. Return it to the oil tank and then connect the other solenoid VS2.
When the pump PM is energized, the circuit is closed and the conduction between the pump PM and the oil tank is cut off.

Figure 5 schematically shows the entire electric circuit, CC
1, CC2, CC3, CCR and CCS are the electromagnetic directional control valves V1 and VS, V2 and VS, V3 and VS, VR and
VS and all electromagnetic directional control valves V1, V2, V3,
Controls the switching of VR and VS, and also controls the clutch CL.
This is a circuit portion for engaging CL1, engaging CL2, engaging CL3, engaging CLR, and disconnecting all clutches. Therefore, the circuit parts CC1, CC2, CC3,
Since the CCRs are configured to have an equal relationship, the circuit portion CC1 shown in FIG. 6 and the circuit portion CCS shown in FIG. 7 will be explained.

CC1 consists of the following series circuit group connected in parallel between the positive and negative electrodes of the battery. In other words, switch F1
A series circuit of the contact F11 and a parallel circuit of the solenoid V11 and the excitation coil M11C of the magnetic relay M11, a parallel circuit of the other contact F12 of the switch F1 and the normally open contact M12a of the magnetic relay M12, and an excitation coil M1 of the magnetic relay M12.
2C, normally closed contact M21b, M31b, MR1b,
Series circuit of MS1b and parallel circuit of lamp F1L of switch F1, series circuit of normally open contact M11a of magnetic relay M11 and solenoid VS2, and normally open contacts M21a', M31
a′, MR1a′, MS1a′ parallel circuit and solenoid V
This is a series circuit with 12.

Note that the normally closed contacts M21b, M31b, MR1
b corresponds to the magnetic reel M11 and CC respectively.
2, CC3, magnetic reel M21 installed in CCR,
Normally closed contacts for M31 and MR1, and MS1b
is the normally closed contact of the magnetic relay MS1 installed in the CCS, and M21a', M31a', MR1a', MS
1a' are the magnetic relays M21, M31,
These are normally open contacts for MR1 and MS1. Note that the magnetic relay itself is not shown in FIGS. 6 and 7, but only the excitation coil and contact points, whose numbers are associated with the numbers of the magnetic relay, are shown in both figures.

Next, the circuit portion CCS in FIG. 7 is also formed by connecting the next series circuit group in parallel between the positive and negative electrodes of the battery. In other words, a parallel circuit of contact ST1 of switch ST and normally open contact _LSa1 of limit switch LS, and a solenoid
Excitation coil MS of VS1 and magnetic relay MS1
Series circuit with 1C parallel circuit, limit switch
A parallel circuit of contact LSa ₂ of LS, contact ST2 of switch ST, normally open contact MS2a of magnetic relay MS2, and excitation coil MS2 of magnetic relay MS2.
C, normally closed contacts M11b', M21b', M31b' and
MR1b' series circuit and switch ST lamp
Series circuit with parallel circuit of STL, normally open contact M11
a'', M21a'', M31a'' and MR1a'' in parallel and a series circuit with solenoid VS2, and a normally open contact MS1a of magnetic relay MS1 and a parallel circuit of solenoids V12, V22, V32 and VR2. Note that the normally closed contact M11
b', M21b', M31b', MR1b' are normally closed contacts of the magnetic relays M11, M21, M31, MR1, and normally open contacts M11a'', M21a'', M
31a'' and MR1a'' are normally open contacts of the magnetic relay.

The agricultural machine according to the present invention switches the transmission PS by controlling the hydraulic circuit shown in FIG. 4 using the electric circuit configured as described above, and these operations are as follows. .

(1) When switch F1 is pressed F11 on → V11 excitation, also M11C excitation M11C excitation → M11a on → VS2 excitation M11C excitation turns on V22, V32, VR2 energization control circuits in CC2, CC3, CCR.

(Refer to the circuit connected to V12 in CC1) In other words, all pressure oil is cut off except for V1.
Pressure oil is supplied to CL1, and the aircraft runs in the first forward speed. V1, V2, V3, VR, VS
Since this is a free position valve, this state will be maintained even if F11 is turned off and V11 is demagnetized.

F12 on → F1L lights up, that is, it can be visually seen that the transmission PS is in the first forward speed.

R12 on → M12C on → M12 is self-maintaining, so even if F12 is turned off, F1L continues to light up.

(2) When switch F2 is pressed The same operation as in item (1) above is performed at CC2, and while the lamp of switch F2 is lit, pressure oil is supplied to clutch CL2 and the vehicle runs in the second forward speed. However, M1 in CC1
The excitation coil corresponding to 1C is turned on and its normally closed contact M21b is opened, so the self-holding of M12 is released at CC1 and F1L disappears.
Conversely, since M21a' is closed, V12 is turned on and the pressure oil supply to CL1 is cut off.

The operation in the CCS is the same as in item (1), and when the switch F3 or FR is pressed, the same operation will result in three forward or reverse speeds.

(3) When the switch ST is pressed or when the limit switch LS is operated by depressing the clutch pedal CP As is clear from the configuration of the circuit CCS in FIG. 7, the same operation is performed by both of the above operations.

ST1 or LSa ₁ on → VS1 excitation, also MS
1C excitation MS1C excitation → MS1a on → V12, V
22, V32, VR2 excitation In other words, the pressure oil is cut off except for VS, and the pressure oil that was being supplied to either clutch returns to the oil tank, while the oil from pump PM flows to VS.
It is refluxed through, and no transmission takes place. For the same reason as before, this state is maintained even if the ST push-in operation or the CP push-in operation is interrupted and ST1 and LSa ₁ are turned off.

ST2 or LSa ₂ on → STL lights up, that is, it can be visually seen that the transmission PS is in a neutral state in which no transmission is performed.

ST2 or LSa ₂ on → MS2C on → MS2
is self-maintaining. Therefore, even if ST2 or LSa ₂ is off, STL
remains lit.

By excitation of MS1C, the MS shown in Fig. 6
1b opens and MS1a' closes, which is performed in CC1, CC2, CC3, and CCR, so lamps such as F1L are turned off and V
1. Pressure oil is reliably shut off by V2, V3, and VR.

As described above, in the agricultural machine according to the present invention, the switches F1, F2, F3, and RS are set in accordance with the desired gear position of forward 1st, 2nd, and 3rd gear, reverse, or neutral.
Or, it can be selected by simply pressing ST, making it extremely easy to operate. And Lord Clutch MC
When the clutch pedal CP is pressed to shut off the transmission, the same control operation as pressing the switch ST to put the transmission PS into the neutral state is performed by operating the limit switch LS.
After the clutch pedal CP is depressed, the neutral state is maintained regardless of the state of the gear before that.
Therefore, unlike conventional mechanical transmissions, there is no risk of sudden start if the clutch pedal is inadvertently lifted, and there is no risk of personal injury. Therefore, the driver is freed from the labor and psychological burden associated with safe work.

In addition, in the present invention, a free-position type solenoid valve is used, and the required electrical signal is given to all of the solenoid valves by a single switch operation, so that the clutch can be engaged or disengaged. In either case, the solenoid valve is forcibly switched, and the clutch is engaged and disengaged reliably and quickly. In addition, since it is only necessary to energize the solenoid in the solenoid valve during the switch operation when changing gears, power consumption can be significantly reduced.Furthermore, the deterioration of the solenoid due to energization is small, and the life of the solenoid valve is long, so it can be used for a long time. Operates stably.

In this way, the present invention ensures operability and safety,
Furthermore, it contributes greatly to improving economic efficiency.
In the above embodiment, a power shift transmission is used as the transmission, but a hydrostatic drive system in which the movable swash plate is operated by a hydraulic circuit as shown in FIG. 4 may also be used. Of course.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a schematic side view of an agricultural machine according to the present invention, and FIG.
The figure is a schematic diagram of the top surface of the console, Figure 3 is a schematic side view of the clutch pedal, Figure 4 is a diagram of the main hydraulic circuit,
FIG. 5 is a main part electric circuit diagram, and FIGS. 6 and 7 are detailed diagrams thereof. PS...Transmission, MC...Main clutch, CP...
...clutch pedal, LS...limit switch.

Claims (1)

[Claims] 1. An electric circuit that controls the oil flow of a hydraulically controlled transmission to a predetermined gear position by operating a switch;
In a traveling agricultural machine equipped with a clutch that connects and disconnects power to the traveling device and a clutch pedal that operates the clutch, a hydraulic circuit connected to the transmission includes a freewheel that corresponds to each gear and neutral state. Position-type solenoid valves are respectively provided, and in order to set the electric circuit to a gear position defined by the switch operation, a configuration is adopted in which a required signal is given to all of the solenoid valves by a single switch operation, In addition, with the clutch disengagement operation using the clutch pedal,
A traveling agricultural machine, characterized in that it is configured to apply necessary signals to all of the electromagnetic valves in order to bring the transmission into a neutral state.