JPH01216035A - Method of controlling engine output based on shoe slip - Google Patents

Abstract

PURPOSE:To enable continual provision of a given tractive force and to improve controllability, by a method wherein, in a scavenging vehicle, based on a shoe slip (crawler slip) ratio, a car speed, and a tractive force, an engine output is automatically controlled. CONSTITUTION:In relation to an engine output full performance curve shown in the tractive force-speed diagram of an engine, the high output part of the engine output full performance curve is cut according to soil or rock. A basic mode is set as an engine output suitable for working operation, and is stored in an output control system. A control mode being an engine output where a part of an engine output during e basic mode is cut off is set, and is stored in a similar manner described above in the output control system. When it is detected during working operation that a shoe slip ratio exceeds a given value, the control mode of the engine is gradually transferred from the basic mode to a control mode, and an engine output is cut off until a shoe slip is eliminated.

Description

[Detailed Description of the Invention] Industrial Application Field: The present invention controls engine output based on shoe slip rate during operation of a tracked vehicle such as a large bulldozer that has working equipment for dosing, ripping, etc. This invention relates to means for easily achieving efficient operation.

Conventional technology The motion of a tracked vehicle such as a nibbledozer is achieved by transmitting engine output to the system procerato wheel through power lines such as a torque converter, transmission, bevel gear, steering clutch, steering brake, and final reduction gear. This is done by driving crawler tracks wrapped around wheels. Therefore, the traction force on the crawler track can be calculated from the engine output and the reduction ratio of the power line.

The engine output of a tracked vehicle is set to the required value by manual operation using the main control lever.The engine output set by this main control lever is reduced by depressing the deceleration pedal, and set by releasing the deceleration pedal. The required output is restored.

The traction force during operation of a tracked vehicle is related to the shoe slip ratio that occurs between the track and the ground. However, the tracked vehicle's engine output is not effectively utilized for traction, resulting in not only energy loss but also problems such as the tracks wearing out in a short period of time.

Conventionally, when excessive shoe slip occurs, the operator senses this and reduces the engine output by depressing the deceleration pedal, and at the same time operates the work equipment to reduce the load, thereby reducing the traction force. This reduces shoe slippage and eliminates shoe slip. When the shoe slip is resolved, release or return the deceleration pedal to its original position.
The engine output had to be returned to the preset steady state output.

Problem to be solved: Shoe slip control by operator operations is performed by the operator recognizing the occurrence of shoe slip visually and sensually, and by reducing the load by operating the work equipment and cutting off the engine output by operating the deceleration pedal. . Therefore,
The operator's operations are complicated and require careful attention, and the training of the operator greatly affects the operation. Even in the case of a skilled operator, it is unavoidable that there is a time lag between the occurrence of a shoe slip and the operator's operation, and some operators often cause unnecessary slips, resulting in shoe slips. The goal of preventing such incidents is difficult to achieve. Furthermore, a similar problem occurs when the engine output is restored to the preset engine output after recovering from a state where excessive shoe slip occurs.

Means for solving the problem: The present invention was made to solve the above-mentioned problems, and it is possible to solve the problem by determining the shoe slip rate, vehicle speed, It detects when traction is present, and based on that, cuts off the engine output to the level that provides the most efficient operating condition. Even when engine output cutoff is no longer necessary due to a change in working conditions, it is detected and the engine output is quickly restored to a preset engine output.

In other words, by automatically controlling the engine output by cutting off and releasing the cutoff according to the shoe slip rate, vehicle speed, and traction force, the system maintains the shoe slip rate within the required shoe slip rate. The engine output necessary to continue the work operation is made to be adaptive so that it is always exerted continuously in an optimal state in relation to traction force and vehicle speed.

Structure and operation of the invention: The method of the present invention is specifically configured as follows.

To detect the actual vehicle speed when inappropriate shoe slip occurs by equipping a tracked vehicle such as a large pull dozer with work equipment for dozing, ripping, etc. with an actual vehicle speed detection mechanism. At the same time, the theoretical vehicle speed and engine speed are detected.

Theoretical vehicle speed can be calculated from the output rotation speed of the torque converter, the shoe slip ratio can be calculated from the theoretical vehicle speed and the actual vehicle speed, and the traction force can be calculated from the theoretical vehicle speed and the engine rotation speed.

To automatically cut off engine output or increase engine output using each of these factors, the soil type to be worked on should be compared to the full performance curve in the engine's traction-speed diagram.

Alternatively, the engine has a so-called basic mode, which is an engine output state in which the high output portion is cut depending on the rock quality (hereinafter simply referred to as soil quality). Furthermore, a so-called control mode is provided in which the engine output is cut off in order to return this value to a set value when the specific shoe slip rate exceeds a specific shoe slip rate in the basic mode.

In the traction force-speed diagram, by providing the engine output state with a basic mode and a control mode having such characteristics, smooth output control becomes possible as described below. That is, when the shoe slip rate exceeds the set value or when the shoe slip detection trigger signal turns ON, the engine output is cut off from the basic mode indicating the engine output required for work operation, and the engine Transfers output to control mode. Excessive shoe slip is eliminated while the engine output is in the control mode, and when a constant shoe slip rate is reached, the control mode returns to the basic mode, allowing efficient work operation to continue.

Therefore, in the method of the present invention, for example, when the engine output is controlled so that the shoe slip shows a desirable shoe slip ratio during ripping forward movement, the following steps are taken: For the curve, set a basic mode that cuts the high output part of the above full performance car according to the soil quality and makes the engine output suitable for work driving, and store it in the output control system; Sets a control mode that is the engine output with partial cutoff and stores it in the output control system; Detects when the shoe slip rate exceeds a predetermined value during work operation; Controls the engine output from the basic mode By gradually shifting to the mode, the engine output is cut off until the shoe slip is resolved. When the shoe slip rate falls below a predetermined value during work operation in the control mode, this is detected; by gradually shifting the engine output from the control mode to the basic mode, the engine output is kept at the level before cutoff. It is possible to perform stable continuous work operation.

Furthermore, when shifting the engine output from the basic mode to the control mode and from the control mode to the basic mode, it is detected that the shoe slip rate is fluctuating from a predetermined value, and in conjunction with this, the vehicle speed and traction force are Whether the vehicle speed/traction force is above or below a predetermined vehicle speed/traction force can be an additional condition for shifting to the two/jin output mode.

In the engine output state shown in the engine traction force-speed diagram, the full performance curve is set for soft sandy soil (shoe slip hardly occurs), so if the soil is hard. If it does, it will not fit properly, resulting in excessive engine output and increased slippage. Therefore, creating a basic mode that cuts the high-output part of the full performance curve will help prevent shoe slips on hard soils and ensure suitable work operation.

In addition, during work operation in the basic mode, the engine output is cut off by multiplying the engine output that generates the traction force at the moment when a predetermined juice V bulge rate (for example, 80%) is reached, by a cutoff coefficient. The control mode, which is a correlation between traction force and speed at the engine output level, shows that by changing the cutoff coefficient according to the soil quality, it is possible to set an engine output mode that is suitable for the work object.

Example: Hereinafter, one specific example of the method of the present invention will be described.

For example, when operating a tracked vehicle such as a large bulldozer that has working equipment for dosing, ripping, etc., looking at the relationship between the traction force F and the vehicle speed V, the engine output increases as shown in Figure 1. At full stroke, the full performance curve is mainly shown by the broken line. The point where this full performance curve of engine output intersects with the Y-axis indicating speed is the upper limit of vehicle speed, and the point where this full performance curve of engine output intersects with the Y-axis indicating traction force is the upper limit of traction force. However, as described above, the traction force of a tracked vehicle is not related to the shoe slip ratio, and the maximum effective traction force is obtained when the shoe slip ratio is constant. Therefore, the traction force and vehicle speed that include this element are determined by the engine output mode, which tends to be as shown by the line cutting the high output part of the full performance curve in Figure 1, as the soil and rock quality becomes harder. , set the basic mode.

In FIG. 1, vo and Fo are the vehicle speed and traction force, which are the origins of the basic mode diagram.

Assume that the bulldozer is moving forward while ripping with the engine output in the basic mode. Steady traction force Fo is 50 tons, constant speed v0 is tb/h
, the predetermined shoe slip rate for turning on the control was set to 30%.

During this work operation, when the vehicle is at point N on the basic mode line in Figure 1, the optimum output differs depending on the soil type (as mentioned above, including rock type), and the shoe slip rate When FN exceeds the set value and the shoe slip detection trigger signal is turned on, the traction force FN at that time is stored in the output control system. The memorized traction force FN
The engine output that is developing is cut off until the shoe slip is eliminated, and a control mode is set whose origin is the traction force FC based on the engine output level at that time.

In this way, if the engine output has a basic mode in which the aim is to perform work operation at a predetermined shoe slip ratio, and a control mode in which the aim is to perform work operation with the engine output cut off, then , an element including a calculation step as shown in FIG. 2 or 4 is installed in the engine output control system.

In this calculation step, when the shoe slip rate reaches a predetermined value, for example, 30es or more, the condition that occurs immediately or when the shoe slip rate exceeds 80% is detected, and then based on the result. to shift the engine output level from basic mode to control mode. This transition occurs gradually over a certain period of time t, for example, from 0 to 8 seconds.

Other conditions in the calculation step shown in FIG. 2 are that the vehicle speed is V as shown in FIG. (in this case 1.0
&s/h. ) and 1.8 &x/ h or more, this is the case when the engine output is within the range where the traction force exceeds Fl.

゛ In this way, the shoe slip ratio exceeds the predetermined value (the above value <8096), the engine output shifts from the basic mode to the control mode, the engine output is cut off, and excessive shoe slip is eliminated. Then, the engine output returns from the control mode to the basic mode. At this time, as shown in the calculation step shown in Fig. 4, when the shoe slip rate falls below a predetermined value, for example, 20% or less, the operation is performed immediately or when the shoe slip rate falls below 20%. After detecting the conditions that sometimes occur, the engine output level is shifted from the control mode to the basic mode and returned based on the results. This transition occurs gradually over a certain period of time t, for example 0 to 3 seconds. Other conditions in the calculation step shown in FIG. 4 are that the vehicle speed is V as shown in FIG. This is a case where the engine output is lower than 0.7 kn/h and the traction force is less than F2.

In this way, the transition from the basic mode to the control mode and the transition back from the control mode to the basic mode are automatically and smoothly carried out, but in addition to these control means, the As such, it is also possible to control engine output by operating the operator's main control lever or Hatchel pedal, which can be used in emergencies to increase the safety and adaptability of work operation.

Effects of the invention: The method of the present invention prevents excessive shoe slip during operation of tracked vehicles such as large bulldozers that have working equipment for dosing, ripping, etc. and maintains an efficient engine output level, thereby improving fuel efficiency. Improves the lifespan of the undercarriage.

In particular, the operator's burden has been reduced by eliminating the need to operate the deceleration pedal. Furthermore, in the event of an emergency, manual operation by the operator is possible, ensuring excellent operational safety.

[Brief explanation of the drawing]

Figure 1 is a traction force-velocity diagram in the method of the present invention, Figure 2
The figure shows the calculation steps when transitioning from basic mode to control mode, Figure 8 is an explanatory diagram of the conditions at the time of transition shown in Figure 2, and Figure 4 is when returning from control mode to basic mode. FIG. 5 is an explanatory diagram of the conditions at the time of transition shown in FIG. 4. VQ VN Far & V Figure 1 Figure 2 % +, 3 y-be Figure J Figure 5 Figure 4 Procedural amendments Indication of the March 23, 1983 incident Title of the invention in Patent Application No. 1983-38928
Relationship to the case of a person who amends the engine output control method based on shoe slips Applicant Address (residence) 2-3-6 Akasaka, Minato-ku, Tokyo Name (123) Komatsu Ltd. Representative Person amendment order date voluntary. Subject of amendment Description: Column for detailed description of the invention.

Claims (1)

[Claims] 1. In controlling engine output based on shoe slip for efficient work operation of a tracked vehicle: With respect to the engine output full performance curve shown in the engine traction force-speed diagram, Set a basic mode that cuts the high output part of the above full performance curve according to the soil or rock quality and makes the engine output suitable for work operation, and store it in the output control system; Cut a part of the engine output in the basic mode. Sets the control mode that is the engine output when it is turned off and stores it in the output control system; Detects when the shoe slip rate exceeds a predetermined value during work operation; Gradually changes the engine output from the basic mode to the control mode. 1. An engine output control method based on shoe slip, characterized in that the engine output is cut off until the shoe slip is eliminated by shifting to the shoe slip. 2. Detecting when the shoe slip rate falls below a predetermined value during work operation in the control mode set forth in claim 1; and gradually shifting the engine output from the control mode to the basic mode. An engine output control method based on a shoe slip, characterized in that: the engine output is returned to the level before the cutoff; 3. When shifting the engine output level from the basic mode to the control mode and from the control mode to the basic mode, it is detected that the shoe slip rate is fluctuating from a predetermined value, and at the same time, the vehicle speed and traction force are adjusted to a predetermined value. The shoe according to claim 1 or 2, wherein the shoe detects whether the vehicle speed and traction force are above or below the vehicle speed and traction force, and uses this as an additional condition for shifting to engine output mode. Engine power control method based on slip.