JPH08119003A - Travel device for work machine, etc. - Google Patents

Abstract

PURPOSE: To keep constant a rotational speed of an engine for driving a travel device, by equipping the engine with a fuel injection means and by controlling a variable-pressure hydraulic motor and the fuel injection means for the engine when the rotational speed of the engine starts to fall due to an increased load on the travel device, in the case of a travel device provided with a variable- pressure hydraulic pump and a variable-pressure hydraulic motor. CONSTITUTION: A travel device for work machines, etc., equipped with a variable-pressure hydraulic motor swash-plate angle change means 9, which controls a swash plate 2a of a variable-pressure hydraulic motor 2 to the lower speed side in order to increase an output torque and also to keep a rotational speed of an engine 5 constant during a travel at a falling speed, and further equipped with a fuel injection means 4 which controls the rotational speed of the engine 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling device such as a working machine.

[0002]

2. Description of the Related Art In a conventional traveling device such as a working machine, among variable hydraulic pumps and hydraulic motors constituting a hydraulic continuously variable transmission, only a variable hydraulic pump is provided with a swash plate to change the oil discharge amount. When the load on the traveling device increases and the engine speed decreases during traveling, the HST lever linked to the swash plate of the variable hydraulic pump is manually or automatically operated. Is used to reduce the vehicle speed or to downshift a mechanical auxiliary transmission provided in the traveling device.

[0003]

In a traveling device such as a working machine as described above, if an excessive load acts on the traveling device during traveling, the engine speed decreases, but the oil of the variable hydraulic pump is reduced. Even if you reduce the discharge amount of
It is impossible to return the engine to normal speed. In the hydraulic continuously variable transmission, the swash plate is naturally provided in the variable hydraulic pump in the past, but the swash plate is not provided in the hydraulic motor. The output torque is constant, so the torque cannot be reduced and the engine speed cannot be increased. Further, even if the mechanical auxiliary transmission is used to increase the torque and reduce the vehicle speed, if gears are difficult to mesh with each other, it takes a long time to respond.

If the engine speed does not return to normal,
For example, taking a combine, which is an agricultural machine, as an example, the driving force of the engine mounted on the combine is not only the traveling device, but also a harvesting device that reaps the planted grain culms, and a threshing device that threshes the harvested grain culms. Etc. are also driven, the rotational speeds of the harvesting device and the threshing device are also reduced. Particularly, in the threshing device, if the number of revolutions is abnormally reduced, the threshing selection performance of the grain culm is significantly reduced. For this reason, in the combine, even if an excessive load acts on the traveling device, it is necessary to always maintain the engine speed normal. The present invention is intended to solve such a problem.

[0005]

A traveling device such as a working machine according to the present invention solves the above problems and has the following structure. That is, in the traveling device having the structure described above, the swash plate 2a of the variable hydraulic motor 2 is controlled to the low speed side to increase the output torque, and the vehicle speed is reduced to keep the rotation speed of the engine 5 constant during traveling. The variable hydraulic motor swash plate angle changing means 9 is provided, and further, the fuel injection means 4 for controlling the rotation speed of the engine 5 is provided.

[0006]

The speed of the engine 5 is increased, the inclination angle of the swash plate 1a of the variable hydraulic pump 1 is changed to an arbitrary position, the amount of oil discharged is increased, and the traveling device 6 is caused to travel. Since the oil discharge amount changes according to the inclination angle of the swash plate 1a, the vehicle speed also changes according to the oil discharge amount. At this time, the swash plate 2a of the variable hydraulic motor 2 is at the optimum output torque position of the standard setting (the tilt angle position that is substantially the same as the maximum tilt angle of the swash plate 1a of the variable hydraulic pump 1), so the hydraulic continuously variable transmission 3 itself. The output torque held by is constant, and only the output rotation speed can be changed. In this way, the traveling device 6
When a load acts on the traveling device 6 while the vehicle is traveling, the rotational speed of the engine 5 decreases. However, when the rotation speed of the engine 5 decreases, for example, in the case of a combine that is an agricultural machine, a problem occurs.
The engine 5 mounted on the combine drives not only the traveling device 6 but also a mowing device for mowing the planted culm, a threshing device for threshing and selecting the mowed culm, and a working machine such as a cutter or knotter. Therefore, when the rotation speed of the engine 5 decreases, the drive rotation speeds of the mowing device, the threshing device, and the working machine also decrease. Particularly, in the case of a threshing device, the performance of threshing selection is deteriorated, so that problems such as mixing of straw debris in the harvested paddy occur.

Therefore, in order to restore the rotation speed of the engine 5 to the normal rotation speed, when the rotation speed detecting means 5a provided in the engine 5 detects a decrease in the rotation speed of the engine 5,
The swash plate angle changing means 9 of the variable hydraulic motor is controlled to increase the inclination angle of the swash plate 2a of the variable hydraulic motor 2 to increase the amount of oil flowing into the cylinder. As a result, it takes time to discharge the oil that has flowed into the cylinder to the outside of the cylinder, so that the number of revolutions decreases, and thus the vehicle speed naturally decreases and the torque increases. In the case of an excessive load in which the rotation speed of the engine 5 does not return to normal even with this control, the fuel injection of the fuel injection means 4 is further increased until the rotation speed of the engine 5 returns, and the engine 5 is properly adjusted. Aim to return to the rotation speed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a combine equipped with an embodiment of the present invention. A traveling device 15 having a pair of left and right crawlers 14 is provided below the chassis 13, and above the chassis 13 a threshing device 17 for threshing selection of grain culms cut by a reaping device 16 provided in front of the chassis 13. , And a grain tank 18 for temporarily storing the grains that have been threshed and selected by the threshing device 17, and further a driver's cab 19 and a driver's seat 20 for driving such a combine are provided on the front right side of the chassis 13. It is provided above. The traveling device 6 for moving the crawler 14 back and forth is attached to the front part of the chassis 13, and the crawler 1 is attached to the end of the traveling shaft 10 output from the traveling device 6.
The sprocket 21 around which 4 is wound is fixed.

Next, FIG. 2 will be described. Traveling device 6
The output shaft 2b of the variable hydraulic motor 2 which is a part of the hydraulic continuously variable transmission 3 is connected to the input shaft 7 of the. The hydraulic continuously variable transmission 3 is further provided with a variable hydraulic pump 1 that receives power from the engine 5. The swash plate 1a connected to the HST lever 8 is attached to the variable hydraulic pump 1.
However, the variable hydraulic motor 2 is also provided with a swash plate 2a connected to the variable hydraulic motor swash plate angle changing means 9. The swash plate 2a of the variable hydraulic motor 2 is usually set at the optimum output torque position (standard position), that is, near the maximum inclination angle of the swash plate 1a of the variable hydraulic pump 1.

When the HST lever 8 is tilted forward, the combine moves forward, but at this time, the swash plate 1a connected to the HST lever 8 tilts, and the swash plate 1a of the swash plate 1a corresponding to the tilt amount of the HST lever 8 tilts. The tilt angle also changes, and the amount of oil discharged to the variable hydraulic motor 2 changes according to the amount of change in the tilt angle of the swash plate 1a. As a result, the rotation speed of the output shaft 2b of the variable hydraulic motor 2 changes, and the rotation speed of the input shaft 7 of the traveling device 6 also changes.
Driving speed changes. H when you move the combine backward
Although the ST lever 8 is tilted to the rear side, the swash plate 1a inclines to the side opposite to that when moving forward, so the direction of oil discharge to the variable hydraulic motor 2 side is also reversed, so the output shaft 2b moves to the opposite side. Rotate. As a result, the rotation of the input shaft 7 of the traveling device 6 is reversed, and the traveling device 6 moves backward.

The variable hydraulic pump 1 is directly connected to the engine 5 when the fuel injection means 4 (hereinafter referred to as an electronic governor) interlocking with the throttle lever is adjusted to increase the rotational speed of the engine 5, and therefore the variable hydraulic pump 1 is directly connected to the engine 5. And the rotation also rises. When the HST lever 8 is in the neutral position, the oil is not sent in the direction of the variable hydraulic motor 2 and therefore the output shaft 2b does not rotate. When the HST lever 8 is moved to the forward side (or the reverse side), the swash plate 1a is tilted via the link mechanism or the like.
(Note that the HST lever may be provided with a position sensor, the swash plate 1a may be linked with a cylinder or a motor, and the swash plate 1a may be moved by an electric signal from the position sensor.) When the swash plate 1a is tilted, oil is released. Oil is sent to the variable hydraulic motor 2 side. Then, the output shaft 2b rotates and the input shaft 7 of the traveling device 6 rotates. After that, the traveling shaft 10 is rotated via the transmission unit 11 at an arbitrary gear ratio.

In the traveling device 6 traveling in this way, when the load on the traveling shaft 10 is increased, the traveling speed is decelerated and the rotational speed of the engine 5 is also reduced. When the rotation speed of the engine 5 decreases, various problems occur. For example, taking a combine, which is an agricultural machine, as an example, the combine includes not only the traveling device 6, but also a harvesting device for harvesting planted grain culms, a threshing device for threshing and sorting the harvested grain culms, and a working machine such as a cutter or knotter. Since they are also being driven, their driving rotational speed is also reduced. In particular,
In the threshing device, if the rotation speed falls below the specified value,
The sorting performance is affected, resulting in the problem that straw debris is mixed in the harvested paddy.

Therefore, it is necessary to maintain the rotation speed of the engine 5 at an appropriate constant rotation, especially at all times, because of the above-mentioned problems. The engine 5 is provided with a rotational speed detecting means 5a so that the rotational speed of the engine 5 is always detected while the traveling device 6 is traveling. FIG.
It is a block diagram showing such an electrical configuration. The central processing unit 22 (hereinafter, referred to as CPU) has an input side connected to a rotation speed detection unit 5a (hereinafter, referred to as a rotation speed sensor), and has an output side at which a variable hydraulic motor swash plate angle changing unit 9 is connected. A fuel injection unit 4 (hereinafter, referred to as a cylinder) and a fuel injection unit 4 (hereinafter, referred to as an electronic governor) are connected to each other. CPU22
Based on the detected rotation speed of the engine 5 input to the CPU 2, the CPU 2 keeps the rotation speed of the engine 5 constant.
A command signal is transmitted from 2. The transmission of this command signal is
The cylinder 9 connected to the swash plate 2a of the variable hydraulic motor 2 is adjusted, the swash plate 2a is further inclined from the standard position, the torque of the variable hydraulic motor 2 is increased, and the rotation speed of the traveling device 6 is reduced. Let As a result, the rotation speed of the engine 5 stabilizes at a substantially constant value.

However, when the load acting on the traveling shaft 10 is further large, the rotation speed of the engine 5 hardly returns from the decelerated rotation. Therefore, the electronic governor 4 is adjusted to increase the fuel injection amount and increase the rotation speed of the engine 5 to restore the engine. As a result, it is possible to keep the rotation speed of the engine 5 constant at all times. Particularly, in a combine that is an agricultural machine, the threshing device whose rotation speed is increased or decreased in connection with the vertical adjustment of the engine rotation speed is always kept constant. Since it rotates at an appropriate number of rotations, the threshing selection capacity does not decrease.
Straws will no longer be mixed in the harvested rice. In the above-described embodiment, the swash plate 2a of the variable hydraulic motor 2 is largely tilted, and the fuel injection of the engine is increased when it is still not possible, but it may be adjusted at the same time.

Further, in the traveling device 6 in which the sub-transmission 12 is set, if the sub-transmission 12 is naturally shifted to the high speed side, it is necessary to move it to the low speed side. At this time, the operator may have forgotten that the sub-transmission 12 has been shifted to the high speed side. Therefore, when the rotational speed of the engine 5 decreases, an alarm sound or a warning light is used to notify the operator. You may. Further, a motor or the like may be provided at the base of an auxiliary gear shift lever (not shown) that shifts the auxiliary gear shift 12 so as to automatically shift to the low speed side.
As a result, when the engine 5 returns to the rotational speed described above, the auxiliary transmission 12 is always arranged on the low speed side, so that the engine 5 can be returned to the rotational speed efficiently.

Next, FIG. 4 will be described. FIG. 4 is a transmission diagram of the combine. As described above, when the load on the traveling device 6 increases during the harvesting work of the combine,
The rotation speed of the engine 5 decreases. At this time, the rotation speeds of the mowing device 16 and the threshing device 17 also decrease. Therefore, particularly in the threshing device 17, when the rotation speed decreases, the grain selection performance decreases and the grain is harvested. A problem occurs that straws are mixed in the grain. Therefore, the speed of the engine 5 is restored as described above, but if the engine 5 cannot be restored even after that, the traveling of the traveling device 6 is stopped. For this stop control, the variable hydraulic pump swash plate angle changing means 23 is provided, and the engine 5
When the rotation speed sensor 5a detects a decrease in the rotation speed of the engine 5, the swash plate 1a is automatically tilted to neutral and the traveling is stopped. In the manual mode, the operator manually moves the HST lever 8 to the neutral position and stops it. When the traveling device 6 is stopped, the mowing device 16 is also automatically or manually stopped by the mowing device stopping means 27, but there is no problem if it is not stopped. (However, unless the reaper 16 is stopped,
The power required to idle the mowing device 16 is wasted. As described above, by stopping the traveling device 6, the rotational speed of the engine 5 can be returned to the proper rotational speed, and the horsepower of the engine 5 can be entirely fed to the threshing device 17. In a combine with a cabin, the air conditioner 31 may be stopped and the horsepower corresponding to the air conditioner 31 may be input to the threshing device 17.

However, the swash plate 1 of the variable hydraulic pump 1
Even if a is neutral, the shaft 1b is directly connected to the engine 5 and therefore is constantly rotating, and the oil is idling in the variable hydraulic pump 1. Since the horsepower required for this purpose is wasted, the power input to the shaft 1b is stopped when the swash plate 1a is neutral. That is, the tension 2 is applied between the output shaft 5b and the shaft 1b of the engine 5 in this embodiment.
A power connection / disconnection means 24, which is composed of 6 and tension / tension means 25, is provided. FIG. 5 is a block diagram showing the electrical configuration of such automatic control. The rotation speed sensor 5a of the engine 5 is provided on the input side of the CPU 22, and the CP
When U22 detects a decrease in the number of revolutions of the engine 5, the variable hydraulic pump swash plate angle changing means 23 is adjusted to be neutral, and
The power cutting means 24 cuts off the power to the shaft 1b, and the harvesting device 1
The power transmission of 6 is also stopped by the reaper disconnecting means 27.
As a result, all the horsepower of the engine 5 can be input to the threshing device 17, so that the sorting performance is improved.

Next, FIGS. 6 to 8 will be described. Figure 6
Is a block diagram, and the threshing device connecting / disconnecting means 28 is connected to the input side of the CPU 22, and the electronic governor 4 is connected to the output side thereof. Furthermore, in the storage unit in the CPU 22,
The optimum rotation speed N of the engine 5 when the threshing device connecting / disconnecting means 28 is connected is stored. Conventionally, engine 5
When the threshing device connecting / disconnecting means 28 (hereinafter referred to as the threshing clutch lever) is turned on and the threshing device 17 is started in a state in which is rotating at a high speed, the transmission system instantly starts rotation. Unreasonable load was applied, which caused damage and shortened life.
If the threshing clutch lever 28 is in the on state when the engine 5 is at a low speed, it takes time to reach the optimum rotation speed (approximately the maximum rotation speed) necessary for threshing selection,
For this reason, when the grain exists in the threshing device 17, there is a drawback that the sorting performance is deteriorated.

Therefore, as shown in FIG. 7, when the CPU 22 detects that the threshing clutch lever 28 is in the engaged state (at this time, the tension 28a is not connected), the optimum rotation stored in the CPU 22 is stored. The electronic governor 4 is controlled so that the number becomes N, and the fuel injection amount is adjusted.
After that, when the rotation speed sensor 5a detects the optimum rotation speed N, the cylinder 28b (which may be an electric motor) is activated, and power is transmitted to the threshing device 17 by the tension 28a. As a result, damage to the threshing transmission system at high speed connection can be eliminated, and deterioration of sorting performance at low speed connection can be prevented. After that, the electronic governor 4 is controlled so that the transmission system of the threshing device is not damaged, and the rotation speed of the engine 5 is gradually increased to the optimum rotation speed necessary for threshing selection as shown in FIG. To go. Alternatively, the method of increasing the engine speed may be the straight line 29 or the curve 30. From the above-described configuration, the rotation speed of the engine 5 can be kept constant at all times, so that the rotation speed of the threshing device 17 can also be kept constant at all times, whereby stable threshing selection work can be performed, and the harvested grains can be covered with straw. No dust is mixed in.

[0020]

Since the present invention is configured as described above, when the load on the traveling device 6 increases and the rotation speed of the engine 5 starts to decrease, the rotation speed of the engine 5 is increased to restore the proper rotation. Since it is configured to, it is possible to run and work efficiently. In particular, in the case of a combine, which is an agricultural machine, since the drive rotation speed of the threshing device is normally maintained, good selection of paddy is possible.

[Brief description of drawings]

FIG. 1 Side view of combine

[Fig. 2] Transmission diagram

FIG. 3 is a block diagram.

[Fig. 4] Transmission diagram

FIG. 5: Block diagram

FIG. 6 is a block diagram.

FIG. 7 is a flow chart diagram.

FIG. 8 is a relationship diagram between the time after the threshing clutch is engaged and the engine speed.

[Explanation of symbols]

1 Variable Hydraulic Pump 1a Swash Plate 1b Shaft 2 Variable Hydraulic Motor 2a Swash Plate 2b Output Shaft 3 Hydraulic Continuous Transmission 4 Fuel Injection Means 5 Engine 5a Rotation Speed Detection Means 5b Output Shaft 6 Traveling Gear 7 Input Shaft 8 HST Lever 9 Variable Hydraulic motor swash plate angle changing means 10 Traveling shaft 11 Transmission section 12 Sub-transmission 13 Chassis 14 Crawler 15 Traveling device 16 Mowing device 17 Threshing device 18 Glen tank 19 Driver's seat 20 Sprocket 22 Central processing unit (CPU) 23 Variable hydraulic pressure Pump swash plate angle changing means 24 Power interruption means 25 Tension tension means 26 Tension 27 Mowing device interruption means 28 Threshing device interruption means 28a Tension 29 Straight line 30 Curve 31 Air conditioning equipment N Optimum rotation speed

Claims (1)

[Claims] 1. A traveling device 6 having a hydraulic continuously variable transmission 3 comprising a variable hydraulic pump 1 having a swash plate 1a and a variable hydraulic motor 2 having a swash plate 2a, and an engine 5 for driving the traveling device 6. A traveling device such as a working machine provided with fuel injection means 4 for changing the rotation speed of the engine 5 and rotation speed detection means 5a for detecting the rotation speed of the engine 5,
A variable hydraulic motor swash plate angle changing means for controlling the swash plate 2a of the variable hydraulic motor 2 to a low speed side to increase the output torque and decreasing the vehicle speed to keep the rotation speed of the engine 5 constant during traveling. 9. A traveling device such as a working machine, which is provided with a fuel injection means 4 for controlling the rotation speed of the engine 5.