JPH018421Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement of a combine harvester equipped with a hydraulic transmission, in which the flow of pressure oil for operating the transmission mechanism of the transmission is controlled by an electric circuit. This proposed a combine harvester with excellent safety and ride comfort.

A combine harvester is known which is equipped with a hydraulically controlled transmission and whose transmission can be changed by operating a switch (for example, Japanese Patent Laid-Open No. 11984/1984). However, this type of combine harvester has problems in terms of safety and poor riding comfort because the gears are changed rapidly by operating a switch. The above-mentioned Japanese Patent Application Publication No. 1975
-11984 also softens the impact when switching between forward and reverse by passing through the neutral position once, but it does not reduce the impact during other gear changes.

That is, in the case of switching from 1st forward speed to 3rd forward speed, the vehicle passes through the intermediate 2nd forward speed, but the acceleration between each changeover is still rapid.

The present invention was made in order to solve these problems, and aims to provide a combine harvester that provides a comfortable ride by gradually changing gears regardless of the gear position, and is free from the danger of sudden starts. purpose.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

Figure 1 is an external view of the combine harvester according to the present invention, where DS indicates the driver's seat and CC indicates the operating column in front of it. The driving force of the engine EG is transmitted via the main clutch (not shown) to the power shift transmission PS (third
(see figure), and further through a side clutch (not shown) to the crawler CR, which causes the aircraft to travel.

Fig. 2 is a perspective view of the switching operation section arranged in the operation column CC, etc., and consists of push-button switches F3, F2, F1, N, and R, arranged in this order from the front side to the rear side of the aircraft. As shown in Figure 4, these five switches, except for switch N, are each equipped with hold coils 1R, 11, 12, 13, etc., and are connected using the respective contacts. It is configured as a one-point selection type, and any one switch is selectively closed. This switch F
3 to R are for generating a speed change signal.
The main contacts are normally open contacts 2R, 21, 2.
2, 23 are used, switches R, F1, F2,
Each of these normally open contacts is closed by the push-in operation of each F3, and the push-in operation of each switch is transmitted as a high-level signal to the corresponding terminal of the input/output port 31 of the microcomputer 30. The switch N is equipped with a normally closed contact 2N, which cuts off the current to the hold coil 1R, releases its self-holding, and connects the normally open contact 2, which was previously closed.
R, 21, 22 or 23 are opened. and a transmission device that allows the aircraft to travel in forward 3rd gear, 2nd gear, 1st gear, or reverse, or to stop.
When switching the PS, switch F3, F2,
F1, R, or N is pressed. Switch N for stop control, which is likely to be operated in an emergency, is connected to other switches F3, F2, F1, and R.
It is made to protrude higher than that. This makes it easy to operate the switch N, prevents erroneous operation, and improves safety when stopping the vehicle in an emergency.

FIG. 3 shows a hydraulic circuit that controls the transmission PS. In the figure, Va and Vb are respectively 5-port 3-position switching type and 4-port 3-position switching type electromagnetic directional control valves (hereinafter referred to as solenoid valves), PM is a pump,
RL is a relief valve, CL1, CL2, CL3,
CLR indicates a hydraulic multi-disc clutch in the transmission PS. The hydraulic circuit configured by these is such that when one solenoid S1 of the solenoid valve Va is excited, pressure oil from the pump PM flows through the solenoid valve.
When the other solenoid S2 is energized, pressure oil is supplied to the clutch CL2 via the solenoid valve Va, and one solenoid S3 of the solenoid valve Vb is energized. If the other solenoid SR is energized, the pressure oil from the pump PM will first pass through the solenoid valve Va and then through this solenoid valve Vb to the clutch CL3, and if the other solenoid SR is energized, the pressure oil from the pump PM will first go through the solenoid valve valve
Va, and then through this solenoid valve Vb to the clutch.
Solenoid valve Va is connected to the upstream side so as to be supplied to CLR.
That is, the solenoid valve Vb is located on the pump PM side, and the solenoid valve Vb is located on the downstream side, that is, on the transmission device PS side that is the load.

Next, a schematic configuration of an electric circuit that is operated by the switching operation section and controls the energization of the solenoids S1, S2, S3, and SR will be explained based on FIG. 4. A microcomputer (hereinafter referred to as microcomputer) 30 is the center of speed change control of the proposed machine.
It stores a CPU (central processing unit) 32, the input/output port 31, control programs, etc.
It consists of a ROM (read-only memory) 33, a RAM (random access memory) 34, and the like. This microcomputer 30 is also used for automatic steering and other automatic controls of this combine, but the control according to the present invention depends on which switch R, F1, F2, or F3 is selected and pressed. This data has become important. CPU32 is switch R or F1,
F2 and F3 are pushed in and the normally open contact 2R or 21,2
2 and 23 are closed and connected to this input/output port 3
When it is detected that the terminal 1 becomes high level, the solenoid SR or the drive circuit 4R of S1, S2, S3 or 41, 4 is activated via the input/output port 31.
2 and 43, energizes solenoids SR or S1, S2, and S3, thereby supplying pressure oil to clutch CLR or CL1, CL2, and CL3 to engage this clutch and move in reverse. (or forward speed 1, 2, 3). In order to avoid damage to the transmission system and shock to the driver due to sudden gear changes, the microcomputer 30 controls the excitation of each solenoid so as to automatically perform step-by-step gear changes. That is, the microcomputer 30 generates a pulse signal as shown in FIG.
2, 43 to solenoid SR or S1, S2,
This energizes S3. For example, if switch F3 is pushed in while switch F1 is pushed in and solenoid S1 is energized to drive in first forward speed, solenoid S1 is demagnetized and at the same time solenoid S2 is energized to drive in second forward speed. After continuing running for a while, solenoid S2 is demagnetized and at the same time solenoid S3 is energized to achieve the desired forward movement 3.
Start running at high speed.

Now, the combine harvester according to the present invention is constructed so that the clutch CLR or CL1 is engaged intermittently at the time of starting or switching between forward and backward travel. This will be explained below based on the flowchart of FIG.

() When F1 is pressed when in neutral, 21 is detected and 2 is turned on, and previously 22,
It is checked that none of 23 and 2R are on, and the drive signals for 10, 12, and 41 are intermittently set to high level, and S1 is intermittently excited 15. and after the passage of time t ₁ 16, 2
Check again that 1 is on and press 17.
S1 continuous excitation 11. Figure 6 A, B, and C show the transmission and drive circuit 4 during the above operations.
1 and the acceleration state of the aircraft. When switch F1 is operated to change gears as shown in Figure 6A, the excitation of S1 is intermittent during time _t1 as shown in Figure 6B, so there is no pump in the oil passage connected to clutch CL1. Pressure oil is intermittently applied from PM. If both the excitation period and the demagnetization period of S1 are short, the pressure in the oil passage is lower than that of the relief valve during one excitation period.
It does not reach the pressure determined by RL. Moreover, the pressure in this oil passage does not drop to the tank pressure during one demagnetization period. As a result, the oil pressure in the oil passage or the oil pressure applied to the clutch CL1 gradually increases from the tank pressure and reaches the pressure of the relief valve RL. Therefore, the clutch CL1 behaves as if it were in a disengaged state, goes through a half-clutch state, and then reaches a clutch engaged state, and the traveling speed gradually increases as shown in FIG. 6C. Thereafter, after S1 is continuously energized, clutch CL1 is continuously engaged and becomes the normal first forward speed.

In this embodiment, as shown in FIG. 6B, the duty ratio of the pulse of the drive signal is made to approach 1 as time passes, thereby achieving smoother starting and acceleration.

() When R is pressed when neutral, 2R on is detected and 1, previously 21, 22, 23
Check that it is not on and 5.SR
is intermittently excited 7, and after time t ₁ has elapsed 8,
Switch SR to continuous excitation. 9.

In this case as well, the vehicle is accelerated backwards and a smooth start is possible.

() If you press F3 when going backwards, detect 23 on, 4, check that 21 and 22 were not on before, 25, 12 above.
Step 2 is entered, and it is checked whether 2R was previously on or not.
1. Both S2 and S3 are de-energized. 13. Let time t ₂ elapse in the neutral state. 14. After that,
Intermittent excitation of S1 is performed for t ₁ in the same manner as in the case () above 15, 16.Next, since neither 21, 22 is on, 17, 19, S2 is continuously excited for t ₃ hours 21 ,22 then S3
Continuously excite 23. In other words, in this case, reverse → neutral (t ₂ ) → intermittent forward 1st gear (t ₁ ) →
The gears are changed from 2nd forward speed ( _t3 ) to 3rd forward speed.

() When R is pressed during forward 2nd speed, 2R is detected as on, 1, it is detected that the previous 22 was on, 5, stepwise deceleration routine 6 is entered, and then SR is energized intermittently for time t ₁ 7 and 8, then move on to continuous excitation of SR.

Therefore, in this case, 2nd forward speed → gradual deceleration (1st forward speed → neutral) →
It changes from intermittent backward movement to continuous backward movement.

As described above, the combine harvester according to the present invention is equipped with a hydraulic transmission device and has a configuration in which an electric circuit controls the oil flow for operating the transmission mechanism of the transmission device, the combine harvester includes a speed change signal generating means,
means for generating a pulse signal for intermittent driving of the transmission mechanism for a certain period of time from the time the signal is generated when the transmission signal generation means generates a transmission signal; and a means for generating a signal for continuous driving of the transmission mechanism after the pulse signal is generated. Since the device is characterized in that it is equipped with a means for
As a result, the speed after the shift or in the intermediate stage can be obtained intermittently, so the speed is gradually shifted and the riding comfort is good.There is also no danger of sudden starts, and the shift is gradual, so especially at the beginning of the reaping process. It is easy to align the rows and prevent uncut leaves. After that, a signal for continuous driving is generated, so that after passing through the transient state during gear shifting, the system automatically returns to the normal state, eliminating the hassle of operation. Further, in order to gradually change the speed, only a pulse signal is used to switch the solenoid valve for the speed change, so no other special mechanism is required and the structure is simple.

In short, according to the present invention, it is possible to realize a traveling type work machine that is safe during operation and has excellent riding comfort.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an external view of a combine harvester according to the invention, Fig. 2 is a perspective view of a switching operation section, and Fig. 3 is a diagram for controlling switching of a transmission. A hydraulic circuit diagram, Fig. 4 is an electric circuit diagram for controlling the energization of the solenoid of the solenoid valve in the hydraulic circuit, Fig. 5 is a flowchart for explaining the control mode of the microcomputer, and Fig. 6 is a, b, and c. is a time chart to explain the operation. PS...Transmission, CLR, CL1, CL2, CL3
...Clutch, SR, S1, S2, S3...Solenoid, Va, Vb...Solenoid valve, 30...Microcomputer.

Claims (1)

[Scope of utility model registration request] A combine harvester equipped with a hydraulic transmission device and configured to control oil flow for operating a transmission mechanism of the transmission device using an electric circuit, comprising a speed change signal generating means, and the speed change signal generating means generating a speed change signal. In this case, the present invention is characterized by comprising means for generating a pulse signal for intermittent driving of the transmission mechanism for a certain period of time from the time when the signal is generated, and means for generating a signal for continuous driving of the transmission mechanism after generation of the pulse signal. combine.