JPH058375Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to improvement of an automatic transmission for a vehicle.

(Prior Art) In recent years, in order to reduce driver fatigue, an increasing number of vehicles are equipped with automatic transmissions that automatically change gears by interposing a torque converter between the engine and the transmission. Since the torque converter is a fluid coupling, the output transmission efficiency is inevitably lower than that of a mechanical clutch, which is disadvantageous in terms of improving fuel efficiency.

Therefore, in order to improve not only ease of operation but also fuel efficiency, we used a conventional transmission and mechanical clutch, and instead of having the driver operate the clutch or transmission, they were automatically controlled by electronic control. The applicant of the present invention has proposed an automatic transmission device in which a gear change operation is performed automatically (see, for example, Japanese Utility Model Application No. 44579/1983).

FIG. 8 is a flowchart showing the control operation, and the basic operation is the same as the operation of an automatic transmission using a torque converter.

In addition, the transmission employs a synchronized mesh mechanism that quickly matches the rotational speeds of the gears that engage, but basically the gears that engage are aligned within a predetermined relative rotational speed difference range (synchronizable range). If they can be accommodated, they can be meshed without causing gear noise, etc., even without a synchronized mesh mechanism.

Therefore, in order to reduce costs, this device omit the synchronized mesh mechanism, which has a complicated structure, and detects the rotational speed of the gears to be meshed, and sets the gears when the two reach the synchronized range (synchronized range). I'm letting it happen.

For example, when shifting up, as shown in Figure 9, if the vehicle speed V increases due to acceleration and it is determined that a shift is necessary, the control lever of the fuel injection pump is returned to the no-load position at steps 21 and 22. At the same time, disengage the mechanical clutch and set the transmission to the neutral position. Incidentally, FIG. 9 is a flowchart showing the operation of the shift-up control performed in step 8 of FIG.

Thereafter, at step 23, the clutch is immediately engaged. This is because in manual shifting, the clutch is normally engaged after the gear shift is completed, but during this time the engine speed drops towards idle speed independent of the axle, and if this drop in speed is large, this occurs when the clutch is engaged. Since the reduced engine speed is rapidly raised to the axle side speed, it acts as a large load on the drive system, causing a gear shift shock. Therefore, in order to reduce this shift shock and further shorten the time required for shifting, the clutch is connected to the engine output shaft except when the transmission is set in the neutral position.

At 24, the gear rotation speed N _g of the main gear idly rotating on the main shaft is detected, and N _g decreases to 2.
When N _g ≦N _syc + ΔN at step 5, it is determined that N _g is in the synchro region, and gear setting to mesh the main gear and main shaft is started, and after the gear setting is completed, the control lever is returned to its original position at step 27. .

Here, N _syc is the rotational speed of the main shaft connected to the axle, ΔN is the tolerance range set as the range in which synchronous meshing can be achieved without gear noise etc. for this N _syc , and N _syc + ΔN is the rotation speed of the main shaft connected to the axle. Gives the upper limit of the area.

For example, when shifting from 2nd to 3rd gear is shown in Figure 10, the synchronization region is indicated by the shaded area, and the rotational speed N _g of the main gear, which is disconnected from the main shaft at point A, is Gear setting is started at point B, which descends and enters the synchronized region, and synchronized meshing is completed at point C.

(Problem to be solved by the invention) By the way, in this earlier application, ΔN set for the rotational speed N _syc of the main shaft at that time.
is a constant value, and the gear shift is performed after waiting for N _g to enter the synchronization region. Therefore, if the gear shift is performed after the vehicle speed has increased, the drop in gear rotation will be large, and this large drop will occur. The time required to complete a shift increases depending on the number of minutes.

This long shift time means that the shift operation cannot be carried out quickly, and the engine output is not transmitted to the axle during the required time and the vehicle runs idle, so it is undesirable for this time to become long. .

Therefore, the object of this invention is to provide an automatic transmission device that reduces the time required for shifting.

(Means for solving the problem) FIG. 1 is an overall configuration diagram showing clearly the configuration of this invention.

Reference numeral 33 denotes a gear shift operation control means which determines the driving range in which the gear shift operation of the transmission is to be performed based on signals from the operating state detection means 30 for detecting the operating state of the engine and the vehicle speed detection means 31 for detecting the vehicle speed. , a control signal is output to the governor control means 35, the clutch engagement/disconnection means 37, and the gear shift means 39 to control the speed change operation.

For example, during gear shifting, the governor control means 35 returns the control lever of the fuel injection pump 36 to the no-load position in response to a control signal to the governor control means 35, and the clutch disengagement means 37 returns the control lever of the fuel injection pump 36 to the no-load position in response to a control signal to the clutch disengagement means 37. cut. Also, by the control signal to the gear shift 39,
Gear shift means 39 sets the transmission in a neutral position.

34 is a synchro determination means, which is a vehicle speed detection means 31.
Based on the detection signal from the gear rotation speed detection means 32 that detects the rotation speed of the main gear, it is determined that synchronization is possible when the rotation speed N _g of the main gear enters the synchronization possible range.

Here, as the main gear synchronization possible range, the rotation speed range N _syc ± is calculated by adding a predetermined value ±ΔN to the main shaft rotation speed N _syc converted from the vehicle speed.
A wide range of either ΔN or a rotational speed range (1±K)N _syc obtained by adding a predetermined ratio ±KN _syc is set.

When it is determined that synchronization is possible, the shift operation control means 3
3 is a gear shift means 39 and a clutch disconnection means 37
The gear shift and the clutch 38 are connected via the gear shift lever 38, and the control lever is returned to its original position via the governor control means 35 after the gear shift is completed.

(Function) With this configuration, the range of (1±K)N _syc is wider than the range of N _syc ±ΔN in a high vehicle speed region, and the synchronizable range of the main gear is expanded by this widening.

Therefore, the rotational speed of the main gear reaches the synchronizable range earlier, and the time required to complete the gear shift can be shortened.

By shortening the time required for shifting, the time during which engine output is not transmitted to the axle can be shortened, and the idle running distance can be shortened.

(Embodiment) Figure 2 is a schematic diagram showing the mechanical configuration of the first embodiment of this invention applied to a diesel engine, and Figure 3 is a schematic diagram showing the mechanical configuration of the first embodiment of this invention applied to a diesel engine.
The figure is also a block configuration diagram. In this example,
The fuel injection pump 41, mechanical clutch 42, and transmission 43 are provided with various detection means for detecting their operating states and actuators for driving them, and a control system consisting of a microcomputer is provided based on signals from these detection means. The unit 60 controls the actuator to achieve automatic gear shifting.

First, a means for detecting the operating state is required as a detection means, and this operating state is determined by the engine load,
This can be determined from the position of the select lever, the engagement/disengagement state of the clutch, the actual shift position of the transmission, and the vehicle speed. For this reason,
An accelerator sensor 50 that detects the depression angle (accelerator opening degree) of the accelerator pedal 45 as an engine load is attached to the accelerator pedal 45 .
8 is a selector position sensor that detects the position of a select lever (selector) 49, a mechanical clutch 42 is a clutch stroke sensor 54 that detects the stroke amount of the clutch, and a transmission 43 that does not have a synchronized mesh mechanism is provided. is provided with a shift position sensor that detects the actual shift position, and a main shaft rotation sensor 56 that detects the rotational speed of the main shaft connected to the axle via the propeller shaft 44. Note that since the main shaft rotation speed is proportional to the vehicle speed, the main shaft rotation speed sensor 56 functions as a vehicle speed sensor.

In addition, synchronization of the gears to be meshed is achieved by driving the gear shift mechanism when the rotational speed N _g of the main gear idly rotating on the main shaft enters a synchronization range established with respect to the rotational speed N _syc of the main shaft. It is necessary to detect the rotational speed N _g . In this case, the main gear is in synchronous mesh with the countershaft that transmits the engine output, so
The rotational speed of the countershaft is equal to the rotational speed N _g of the main gear, and for this reason a countershaft rotation sensor 57 is provided.

Next, for these detection means, the fuel injection pump 41 is an actuator that is controlled by the control unit 60, and is equipped with a control lever to drive the control lever according to the request and to match the engine rotation with the requested rotation. A governor control device 53 that controls engine rotation is connected to the clutch 4.
2 is provided with a clutch actuator 55 that engages and engages the clutch, and the transmission 43 is provided with a gear shift actuator 59 that drives the gear shift mechanism and sets a gear shift.

A control unit 60 that controls these actuators operates a governor control circuit 63 and a transmission control circuit 64 based on detection signals from an accelerator opening sensor 50 and the like as a driving state detection means and a main shaft rotation sensor 56 as a vehicle speed detection means. , a shift change control circuit 61 that controls a gear change operation via a clutch engagement control circuit 65;
It is comprised of a synchronization determination circuit 62 that determines whether or not a synchronization action is to be performed based on the rotational speed signals from the main shaft rotation sensor 56 and the countershaft rotation sensor 57.

Here, the function of the synchro determination circuit 62 is the essential part of this invention, and it determines the rotation speed range N _{syc ± by adding a predetermined value ±ΔN to the main shaft rotation speed N syc .}
The rotation speed range (1 ± K) N _syc , which is the sum of ΔN or a predetermined ratio ±KN _syc , is set as the synchronizable region, and the rotation speed of the main gear is
When N _g falls within this synchronizable region, it is determined that synchronization is possible.

In addition, in this example, so that only the clutch operation at the time of starting can be performed manually, a clutch pedal switch 67 that detects the depression of the clutch pedal 46 and an accelerator opening degree of the accelerator pedal 45 are used to directly inject fuel. A switching device 68 is provided which communicates with the control lever of the pump 41.

FIG. 4 is a flowchart illustrating the operations performed by the control unit 60, and shift-up control will be explained based on this flowchart. The numbers in the figure indicate processing numbers.

Synchro judgment circuit 62 as the main part of this invention
This function is performed by 25 and 28. That is,
In case of shift up, N _g ≦N _syc + ΔN or
The larger of N _g ≦ (1 + K) N _syc is set as the upper limit of the synchronization area, and even if N _g ≦ N _syc + ΔN, and even if N _g is N _g > N _syc + ΔN.
If N _g ≦N _syc +KN _syc , it is determined that synchronization is possible, and the gear shift mechanism is driven at step 26 to set a gear shift.

When this synchronization area is illustrated in FIG. 5, the hatched area corresponds. That is, N _syc +ΔN or (1+K)N _syc gives the upper limit value of the synchronization area.

Here, N _syc is proportional to the vehicle speed V, and ΔN is a constant value, so in a region where the vehicle speed is small, N _syc is also small and the ratio of ΔN to N _syc becomes large, but in a region where the vehicle speed is high, N _syc is also large. , the ratio of ΔN to N _syc becomes small. On the other hand, KN _syc
Since it increases with N _syc , the ratio of KN _syc to N _syc is small in a region of low vehicle speed, but the ratio of KN _syc to N _syc becomes large in a region of high vehicle speed. Therefore, in the region of high vehicle speed, N _syc
(1+K)N _syc is larger than +ΔN, and the synchronization region expands as the vehicle speed increases.

Therefore, when a gear shift operation is performed from a high vehicle speed, gear setting is started when N _g reaches point D, so the time required for shifting can be shortened. By shortening it, it is possible to shorten the idle running distance where engine output is no longer transmitted. However, in the prior application, gear setting is not started until point B is reached, and the time required for shifting becomes longer by the time required between DB.

In the case of downshifting, the smaller of N _syc -ΔN or (1-K)N _syc provides the lower limit value of the synchronization region. In this case N _g
If ≧N _syc −ΔN or N _g ≧(1−K)N _syc , it is determined that the synchronization is possible. That is, gear setting is started at point E. That is, gear setting is started at point E.

Here, an example in which the value of K is set to be the same regardless of the shift stage is shown in FIG. 6, but it is preferable to change the value and set it uniquely for each shift stage. The figure also shows the value of ΔN for comparison.

FIG. 7 is a diagram illustrating the synchronization area of the second embodiment of this invention. The synchronization area is provided with a predetermined allowable width (±ΔN or ±KN _syc ) above and below N _syc of each shift stage, but when shifting up, an area smaller than N _syc is unnecessary.
Even if only the area larger than N _syc is used as the synchronization area, the same effects as in the first embodiment can be achieved. Therefore, in this example, when downshifting, an area smaller than N _syc shown in FIG. 5 is set as a synchronization area.

Although the case where the present invention is applied to a diesel engine has been described here, the present invention can be similarly applied to a gasoline engine.

(Effects of the invention) In this invention, a synchronization determination means is provided that determines a wide range of rotation speeds that are above and below the main shaft rotational speed by a predetermined value or by a predetermined percentage as a synchronizable range of the main gear. By expanding the synchronization area when shifting from a high vehicle speed, it becomes possible to shorten the time required for shifting, and by shortening the required shifting time, it is possible to shorten the idle running distance where engine output is no longer transmitted.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram to clarify the configuration of this invention, FIG. 2 is a schematic diagram explaining the mechanical configuration of the first embodiment of this invention, and FIG. 3 is a block diagram of this embodiment. FIG. 4 is a flowchart explaining the operations performed within the control unit, FIG. 5 is a characteristic diagram explaining the synchronization area of this embodiment, FIG. 6 is a table showing an example of the values of K and ΔN, and FIG. FIG. 7 is a characteristic diagram illustrating a synchronization region showing a second embodiment of this invention. 8 and 9 are flowcharts explaining the operation of the earlier application, and FIG. 10 is a characteristic diagram explaining the synchronization area in the earlier application. 30... Operating state detection means, 31... Vehicle speed detection means, 32... Gear rotation speed detection means, 33...
Shift operation control means, 34... synchronization determination means,
35... Governor control means, 36... Fuel injection pump, 37... Clutch disconnection means, 38... Mechanical clutch, 39... Gear shift means, 41... Fuel injection pump, 42... Clutch, 43... Transformer Mission, 49... Selector, 50... Accelerator opening sensor, 51... Selector position sensor, 53... Governor control device, 54... Clutch stroke sensor, 55... Clutch actuator, 56... Main shaft Rotation sensor, 57
... Counter shaft rotation sensor, 58 ... Shift position sensor, 59 ... Gear shift actuator, 60 ... Control unit, 61 ... Shift change control circuit, 62 ... Synchro determination circuit, 63 ... Governor control circuit, 64... Transmission control circuit, 65... Clutch disconnection control circuit.

Claims (1)

[Scope of utility model registration request] The driving range for transmission gear change operation is determined based on the engine operating condition and the vehicle speed, and the mechanical clutch is engaged to synchronously connect the main gear and the main shaft, which rotate freely on the main shaft. A vehicle characterized in that an automatic transmission is provided with a synchronization determination means for determining a wide range of rotational speeds that are above or below a main shaft rotational speed by a predetermined value or by a predetermined percentage as a synchronizable region of the main gear. Automatic transmission.