JPH0241068Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automobile transmission, and more particularly to an automobile transmission in which an actuator is actuated by an electric signal from a controller installed in the driver's seat to select a transmission gear. Regarding.

In the case of a large rear-engine bus, an engine is placed at the rear end of the vehicle body, and a transmission is attached to this engine. In contrast, the driver's seat is located at the front of the vehicle. Therefore, when performing a gear change operation on the transmission of such a bus, if the control lever installed in the driver's seat is transmitted to the transmission via a link, the transmission will be transmitted to the transmission via a link with a length approximately equal to the entire length of the vehicle. Requires link. Therefore, if the movement of the operating lever is transmitted to the transmission using such a mechanical method, not only will the operating lever become heavier, but there is a possibility that the transmission will not be able to shift gears reliably. be.

In order to eliminate such problems, a controller is installed in the driver's seat so that different electrical signals are obtained depending on the operating position of the control lever, and this electrical signal is supplied to the actuator installed in the transmission. This makes it possible to shift gears of the transmission with extremely light operations. Furthermore, since no mechanical connection is required between the controller and the transmission, the structure is also advantageous in terms of simplicity.

However, in automobile transmissions with this structure, there is no mechanical connection between the controller and the transmission, so the driver can control the meshing status of the gears in the transmission through the control lever. It has the disadvantage of not being communicated. Therefore, it is also possible to downshift from a gear position with a low gear ratio, such as fifth gear, to a gear gear position with a high gear ratio, such as first gear. However, when such a sudden downshift is performed, the engine is driven by the vehicle, and the engine speed becomes abnormally high. That is, the engine will be driven at a rotational speed exceeding its rated rotational speed, which may cause damage to the engine.

Therefore, in preparation for such a situation, for example, a microcomputer is used to calculate the engine speed when the engine is downshifted, and if the calculated engine speed exceeds the rated speed, even if the driver The actuator is prevented from operating even if the lever is operated.

Figure 1 is a flowchart showing the operation of a conventional microcomputer for engine protection. It's crowded. Furthermore, this microcomputer reads the vehicle speed from the vehicle speed sensor. Based on these two pieces of information, the engine rotational speed when the transmission is shifted to the gear specified by the controller is calculated. Then, it is determined whether or not the engine speed is below the rated speed, and only when the speed is below the rated speed, a shift control signal is supplied to the actuator. Therefore, if it is determined that the engine speed will exceed the rated speed by shifting, the generation of the speed change control signal will be blocked, and even if a speed change command is issued by the controller (operation lever), the transmission will not be activated. This means that the transmission will not be able to change gears. Such a configuration makes it possible to protect the engine.

However, if the service brake fails, for example, it is necessary to downshift the transmission to a higher gear ratio and apply engine braking, even if the engine speed exceeds the rated speed. However, when the transmission is controlled by a microcomputer that operates as shown in the flowchart shown in Figure 1, even if the brakes fail, it is determined that the engine speed exceeds the rated speed. If
It becomes impossible to downshift to a position with a high gear ratio, resulting in the inconvenience that engine braking cannot be used.

The present invention was developed in view of these problems, and normally, when the engine speed exceeds the rated speed, the transmission is prohibited from shifting to the gear of that gear ratio. In addition, the present invention provides an automobile transmission device that allows the above-mentioned shifting operation to be performed even if the engine speed exceeds the rated speed in an emergency situation, thereby further improving safety. The purpose is to

In order to achieve the above object, the present invention includes a controller that outputs a speed change command signal according to the position of a control lever operated by the driver, and a transmission system that outputs a speed change command signal based on the speed change command signal output from this controller. an actuator for operating the engine to change gears, a calculation means for calculating the engine rotation speed after the gear change based on the speed change command signal, and a calculation means for calculating the engine rotation speed after the speed change based on the speed change command signal; In an automobile transmission device equipped with a prohibition means for prohibiting the gear shifting operation of the transmission,
A detection means for detecting an emergency situation is provided, and when the detection means detects an emergency situation, the actuator is actuated based on the speed change command signal regardless of the output of the inhibiting means. The present invention is characterized in that it is provided with a means for allowing the transmission to change gears.

This configuration prevents a sudden downshift that would cause the engine speed to exceed the rated speed under normal conditions without an emergency situation, but in the event of an emergency situation, the engine speed will be reduced. Even when the number of revolutions exceeds the rated number of revolutions, it is possible to forcibly shift to a gear position specified by the controller, thereby further increasing the running safety of the automobile.

The present invention will be explained below with reference to an illustrated embodiment.
FIG. 2 shows a bus equipped with a transmission according to this embodiment, and an instrument panel 1 is provided inside the bus on the front end side. A steering handle 2 is attached to the front.
A driver sits in a driver's seat 3 and operates a lever 2 to steer the vehicle. A controller 4 is provided on the left side of the driver's seat 3, and by operating an operating lever 5 of the controller 4, a transmission 7 is operated via a microcomputer 6. . The transmission 7 is attached to an engine 8 located at the rear end of the bus body.

As particularly shown in FIG. 3, the transmission 7 is provided with a select cylinder 9 and a shift cylinder 10 at its upper portion.
The select cylinder 9 is a cylinder for selecting a rod to be shifted, whereas the shift cylinder 10 is a cylinder for shifting a selected shift rod. Each of these cylinders 9 and 10 is provided with a pair of electromagnetic valves 11.
Both ends of the cylinders 9 and 10 are connected to an air tank 12 via the air tank 1 . The microcomputer 6 is adapted to supply control signals to the electromagnetic valves 11 provided in the cylinders 9 and 10. Also, this transmission 7
A shift position detection sensor 13 is provided at the top of the shift position detection sensor 13 to detect the gear position of the transmission in use. The detection output of this sensor 13 is sent to the microcomputer 6.
Feedback is provided to

The cylinders 9 and 10 have a structure as shown in FIG. 4, and a piston 14 is disposed therein, and a rod 15 is fixed to the piston 14. Furthermore, small holes 16 are formed at both ends of the cylinders 9 and 10, and these small holes 16
is connected to the outlet port of the electromagnetic valve 11. On the other hand, the inlet port of the electromagnetic valve 11 is connected to the air tank 12.

Therefore, as shown in FIG. 4, when both the coils of the electromagnetic valves 11 on both sides are excited,
Air pressure is applied to both sides of the piston 14, which causes the piston 14 to stop at a central position in the length direction of the cylinders 9, 10. In response, the coil of the right electromagnetic valve 11 is energized,
When the coil of the left electromagnetic valve 11 is demagnetized, the air in the space on the left side of the piston 14 is exhausted through the exhaust port of the electromagnetic valve 11, so that the piston 14 moves to the left side of the cylinders 9, 10. If the right electromagnetic valve 11 is demagnetized and the left electromagnetic valve 11 is excited, the piston 14 will move to the right side of the cylinders 9, 10. The cylinders 9, 10 are thus arranged to assume three stable positions. Therefore, the transmission 7 is switched to each gear ratio by the combination of the operations of the select cylinder 9 and the shift cylinder 10, which perform such operations.

FIG. 5 shows the relationship between engine rotational speed and vehicle speed at each gear ratio of the transmission 7, and shows that the smaller the gear ratio is, the faster the vehicle speed at which the rated rotational speed is reached is. Conversely, this shows that when the engine gear ratio is large, the rated engine speed is quickly reached even if the vehicle speed is small. Furthermore, the lower half of FIG. 5 shows the relationship between the vehicle speed and the gear position of the transmission 7. In this figure, the lower left portion of the chain line 17 indicates the rated rotation range of the engine 8, and the upper right portion of the diagonal line 17 indicates the overrun region. Therefore, in order to protect the engine 8, the lower left portion of the chain line 17 in FIG. 5 must be used.

Next, the operation of the automobile transmission device having the above configuration will be explained. When changing the gear ratio of the transmission 7, the control lever 5 of the controller 4 provided next to the driver's seat 3 may be operated and moved to a desired position. This causes the controller 4 to generate a corresponding electrical signal and supply this electrical signal to the microcomputer 6. The microcomputer 6 is
When a shift command signal is supplied from the controller 4, a shift operation is performed based on the flowchart shown in FIG.

That is, the microcomputer 6 reads the vehicle speed using the vehicle speed sensor 18 shown in FIG. 8. Calculate the number of rotations. This calculation is performed based on the current vehicle speed and the transmission gear ratio after the shift. Then, it is determined whether or not this calculated value is within the rated rotation range of the engine shown in FIG. 5. If it is within the rated rotation range, the microcomputer 6 generates a speed change control signal.

This speed change control signal is supplied to the electromagnetic valves 11 provided in the two cylinders 9 and 10, respectively, so that the pair of cylinders 9 and 10 are operated. That is, for example, when the right electromagnetic valve 11 of the cylinder 9 shown in FIG. 4 is energized and the left electromagnetic valve 11 is demagnetized, the piston 1 of this cylinder 9
4 moves to the left as described above. In this way, the cylinder 9 selects the shift rod, and the cylinder 10 moves the selected shift rod. As a result, the gear of the transmission 7 is selected, and its gear ratio is changed.

Next, assuming that the transmission 7 is switched to the gear shift position selected by the controller 4, if the calculated rotational speed of the engine 8 is equal to or higher than the rated rotational speed, in principle, this transmission 7 is not performed. Therefore, from this, it is possible to prevent the rotation speed of the engine 8 from reaching the overrun region, and it becomes possible to suppress the rotation speed of the engine 8 to the rated rotation speed. Therefore, the engine 8 can be protected by this. At this time, a warning is issued by the driver using the warning means 19.

However, even if the above calculated rotational speed of the engine 8 is equal to or higher than the rated rotational speed, if the microcomputer 6 detects that there is an emergency situation,
A speed change operation of the transmission 7 is performed.
This speed change operation is performed by detecting whether or not a speed change command signal is continuously supplied to the microcomputer 6 for a certain period of time. That is, for example, if the service brake fails and braking is performed using the engine brake, the driver's seat ignores the warning from the warning means 19 and keeps the operating lever 5 of the controller 4 in the switching position for a predetermined period of time. Try to keep it. Then, by this holding, the microcomputer 6 knows that there is a continuous command.
In this case, even if the calculated rotational speed of the engine is higher than the rated rotational speed, the speed change control signal will be supplied from the computer 6 to the electromagnetic valve 11. Therefore, in such an emergency situation, the transmission 7 is switched to a high gear ratio position, making it possible to brake the vehicle by applying engine braking. Therefore, by such an operation, safer gear shifting can be performed.

Next, the operation of a modification of the above embodiment will be explained with reference to FIG. In the above embodiment, the microcomputer 6 detects an emergency situation such as a brake failure depending on whether or not continuous commands are issued from the controller 4. A microcomputer 6 detects the operating speed of the operating lever 5, and detects whether or not an emergency situation exists depending on whether the operating speed exceeds a predetermined value.

Generally, when performing normal gear shifting operations on the transmission 7, the operating lever 5 is operated relatively slowly, but when the engine brake is suddenly applied due to a brake failure, for example, the operating lever 5 is operated relatively slowly. The operation of the operating lever 5 will be performed at a faster speed. Therefore, by detecting an emergency situation based on the operating speed of the control lever 5, the transmission 7 can be set to a high gear ratio even if the calculated engine speed is higher than the rated speed. This makes it possible to obtain braking force in an emergency. Moreover, according to such a modification, braking force due to engine braking can be obtained more quickly,
This will further improve safety.

Although the present invention has been described above with reference to an illustrated embodiment and modifications thereof, the present invention is not limited to these embodiments and modifications, and various modifications may be made based on the technical idea of the present invention. It is possible. For example, in the above embodiment, an abnormality is detected based on whether or not a shift command signal is continuously supplied, and in the above modification, an abnormality is detected depending on whether the speed of the shift operation is equal to or higher than a predetermined value. Although the emergency situation is detected by other methods, the actuator may be operated in conjunction with the detection of the emergency situation.

As described above, the present invention is provided with a detection means for detecting an emergency situation, and when the detection means detects an emergency situation, the calculated engine rotation speed is changed to the rated rotation speed. The actuator is operated to perform a gear change operation even when the speed exceeds the maximum speed. Therefore, according to the present invention, the engine is normally protected by preventing a downshift that would cause the engine to exceed its rated speed, and in an emergency, the above downshift is enabled and engine braking is applied. Since braking force is obtained, safety in an emergency situation is improved.

[Brief explanation of the drawing]

Fig. 1 is a flowchart showing the operation of a conventional automobile transmission to protect the engine; Fig. 2 is a plan view of essential parts of a bus equipped with a transmission according to an embodiment of the present invention; Fig. 3; is a block diagram showing the transmission installed in this bus, Figure 4 is a cross-sectional view of the cylinder attached to the transmission of this transmission, and Figure 5 is the rotation of the engine with respect to the vehicle speed of this transmission. FIG. 6 is a flow chart showing the operation of this transmission, and FIG. 7 is a flow chart showing the operation according to a modified example. In addition, in the symbols used in the drawings, 4...controller, 5...operation lever, 6...microcomputer, 7...transmission, 8...engine, 9...select cylinder, 10...shift cylinder, 11 . . . Solenoid valve, 18 . . . Vehicle speed sensor.

Claims (1)

[Scope of utility model registration request] a controller that outputs a gear change command signal according to the position of a control lever operated by a driver;
an actuator that shifts the transmission based on the shift command signal output from the controller; a calculation means that calculates the engine rotation speed after shifting based on the shift command signal; In the automobile transmission system, a detection means is provided for detecting an emergency situation, and a prohibition means for prohibiting the gear shift operation of the transmission by the actuator when the rotation speed of the engine exceeds the rated rotation speed. A means is provided for operating the actuator based on the gear change command signal to permit the transmission to change gears regardless of the output of the inhibiting means when an emergency situation is detected by the detection means. An automobile transmission device characterized by: