JPH0535309B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a shift control device for an automatic transmission for a vehicle, and more particularly to a shift control device for an automatic transmission for a vehicle that automatically switches between a plurality of forward gears and reverse gears.

[Conventional technology]

In an automatic transmission, increasing the number of gears achieved reduces the amount of fluctuation in engine speed during gear shifting, which reduces the amount of energy that the friction material must absorb and improves the durability of the friction material. At the same time, torque fluctuations (shift shocks) during gear shifting can be significantly reduced. Conventionally, in order to increase the number of gears achieved and to reduce design changes to existing automatic transmissions for manufacturing advantages, existing automatic transmissions have been developed that are capable of automatically changing gears at least in relation to vehicle speed. An automatic transmission that can achieve a large number of gears by using an automatic transmission as the main transmission and arranging in series a sub-transmission that can switch between a low speed side and a high speed side. machine is known. For example, an overdrive device (O/D) that automatically switches between overdrive as a high speed gear and non-overdrive as a low gear (non-overdrive is a reduction ratio of 1, for example) is connected to the main transmission as an auxiliary transmission. For automatic transmissions that are connected in series on the input side or output side of
Multi-stage speed change can be achieved. By increasing the number of gears achieved in this way, it is possible to improve the durability of the friction material and reduce the shift shock during gear shifting, as described above, and because an excessive load is not placed on the engine,
Good results can also be obtained in terms of fuel efficiency and power performance.

【table】

[Problem to be solved by the invention]

However, in the case of an automatic transmission that achieves multi-speed shifting as described above, the greater the number of gears, the more complicated the shift control becomes, and the frequency of shifting increases, causing discomfort to the driver. There was a problem that there was. In particular, as mentioned above, in the case of an automatic transmission of the type that is equipped with a main transmission and a transmission and changes speed simultaneously or alternately, the gear stage of the entire automatic transmission is, for example, from 2nd speed to 3rd speed. to, or the fourth
When upshifting from 5th gear to 5th gear, the gear position of the main transmission is upshifted, but the gear position of the auxiliary transmission is downshifted. Also, the gear stage of the entire automatic transmission may change from 5th gear to 4th gear, or 3rd gear.
When the vehicle is downshifted from the first gear to the second gear, the gear of the main transmission is downshifted, but the gear of the auxiliary transmission is upshifted. When the shifting directions of the main transmission and the auxiliary transmission are reversed as described above, there is a problem in that the shift feeling becomes worse unless the timing of the shifting operation is appropriately and strictly controlled. The present invention has been made in view of these conventional problems, and has been developed to increase the number of gears in order to improve the durability of friction materials, reduce torque fluctuations during gear shifting, improve fuel efficiency, and improve power performance. Shift control for automatic transmissions for vehicles that eliminates driver discomfort caused by increased shift frequency or misalignment of the shift timing of the main and auxiliary transmissions, while maintaining the advantages of automatic transmissions. The purpose is to provide equipment.

[Means to solve the problem]

As shown in FIG. 1A, the first invention provides a shift control device for a vehicle automatic transmission that automatically switches between a plurality of forward gears and reverse gears.
An engine load detection means for detecting an engine load is associated with the engine load, and when the engine load is high, a first shift pattern that achieves a large number of gears is set, and when the engine load is low, the first shift pattern is set. Shift pattern setting means for setting a second shift pattern that achieves a small number of gears excluding some gears between the lowest gear and the highest gear among the gears set by the gear shift pattern. Based on the engine load detected by the engine load detection means, when the engine load is high, the shift is executed according to the first shift pattern, and when the engine load is low, the shift is executed according to the second shift pattern. The above object is achieved by providing a speed change execution means for performing a speed change. As shown in FIG. 1B, the main structure of the second invention is such that a main transmission that achieves a plurality of forward and reverse gears and a sub-transmission that achieves a plurality of low and high speed gears are connected in series to each other. In a shift control device for a vehicle automatic transmission that automatically switches between a main transmission and an auxiliary transmission, an engine load detection means for detecting an engine load is connected to the engine load, and when the engine load is high, the minimum A first shift pattern is set that achieves a number of gears including a gear that is achieved by simultaneously shifting the main transmission and the sub-transmission in opposite directions between the gear and the highest gear, and the engine load is reduced. When the transmission speed is low, a second gear shift is performed to achieve a smaller number of gears than the gears set by the first gear shift pattern, excluding a gear gear achieved by simultaneously shifting at least the main transmission and the auxiliary transmission in opposite directions. When the engine load is high, a shift is performed according to the first shift pattern, based on the engine load detected by the shift pattern setting means for setting the shift pattern of the first shift pattern, and the engine load detection means. When is low,
The above-mentioned object is achieved by providing a shift execution means for executing a shift according to the second shift pattern.

[Effect]

In the first invention, when the engine load is high, the number of gears that can be achieved is large, and therefore, the gears can be shifted smoothly without applying an excessive load to the engine, and as a result, the durability of the friction material is improved and the fuel efficiency is increased. It is possible to fully utilize the advantages of multi-speed transmission, such as improvement in power performance, improvement in transmission shock, and improvement in transmission shock. Also, when the engine load is low, some gears between the highest and lowest gears are thinned out so that the number of gears achieved is reduced, which reduces the frequency of gear changes and reduces the driver's It can relieve the discomfort of Furthermore, when the engine load is low, the friction material is in a state where there is no problem with its durability, and the driver is also likely to be in a state where they want stable driving rather than power.
The fact that the number of intermediate gears achieved is small makes it possible to obtain a good overall effect. On the other hand, the second invention applies the first invention to a type of automatic transmission that may achieve multi-speed shifting by shifting the main transmission and the auxiliary transmission simultaneously and in opposite directions. It is something. in this case,
Since a gear position that allows simultaneous reverse shifting is selected as the gear position to be thinned out, a shift that is difficult to control does not occur, and shift shocks can be reduced, especially when the engine load is low.

【Example】

Embodiments of the present invention will be described in detail below based on the drawings. FIG. 2 shows an example of an automatic transmission with a torque converter to which an embodiment of the shift control device for a vehicle automatic transmission according to the present invention is applied. This automatic transmission 10 includes a torque converter 14 that receives the output of an engine 12, a main transmission 16 that has two planetary gears achieved by a Simpson type gear train, and is capable of switching between three speeds.
arranged in series relation on the output side of the main transmission 16;
It is equipped with an auxiliary transmission 18 that can switch between a low speed side and a high speed side, so that the output of the engine 12 can be shifted to a maximum of six forward speeds and transmitted to an output shaft 20. That is, this automatic transmission 10 is configured to transmit signals from a throttle sensor 22 that detects the throttle opening that reflects the load condition of the engine 12, a vehicle speed sensor 24 that detects vehicle speed, etc. to a central processing unit 26. Therefore, the electromagnetic solenoid valves S ₁ , S ₂ , S ₃ in the main transmission control hydraulic circuit 28 and the electromagnetic solenoid valve S ₄ in the sub-transmission control hydraulic circuit 30 are driven according to a preset shift pattern.・It is controlled and gear change control is performed. The solenoid valves S ₁ and S ₂ are connected to the main transmission 16.
The electromagnetic solenoid valve _S3 controls a lock-up clutch (not shown). Also, electromagnetic solenoid valve S ₄
is adapted to switch the sub-transmission 18 between low speed and high speed. In addition, the reference numeral 32 in the figure is a shift position sensor that detects the positions of N (neutral), D (drive), R (reverse), etc. operated by the driver, and 34 is a pattern select switch. E (economic driving) and P (power driving) are selected, and 36 indicates a water temperature sensor that detects the engine cooling water temperature, and 38 indicates a brake switch that detects the operation of the brake. Next, the control flow executed by the embodiment device is shown in the third section.
This will be explained with reference to the flowchart shown in the figure. First, when the engine 12 is started, the step
The process proceeds to step 110, and in the main routine, six forward gears are determined according to the vehicle speed and throttle opening.
Next, if it is determined in step 120 that the shift is an upshift, the process proceeds to step 130, where it is determined whether the throttle opening θ is larger than a predetermined throttle opening θ ₀ . If the throttle opening θ is determined to be larger than the set opening θ ₀ , it is determined that the throttle opening is high, and step 160 is performed.
In step 190, shift control is performed for up to six forward gears utilizing all of the shift patterns obtained by the main transmission 16 and the auxiliary transmission 18, and in step 190, the corresponding solenoid is driven. On the other hand, in step 130, the throttle opening θ
If it is determined that the throttle opening degree θ is smaller than the throttle opening θ ₀ , the process proceeds to step 140 and the number of gears is changed to 4.
In order to shift the main transmission 16 to the highest speed, that is, 3
It will be judged whether you entered quickly or not. If it is determined that the main transmission 16 is not in third gear, the process proceeds to step 170, where the auxiliary transmission 18 is fixed to the low speed side and gear change control is executed using only the main transmission 16, and then step 190 is performed. A corresponding solenoid actuation takes place. If it is determined in step 140 that the main transmission 16 is in third gear, the process proceeds to step 150, where the auxiliary transmission 18 is allowed to shift, and shifts according to a predetermined shift diagram. As soon as the conditions are met, a signal is issued to shift the auxiliary transmission to the high speed side, and the corresponding solenoid is driven in step 190. If it is determined in step 120 that it is not an upshift, the process proceeds to step 125, where it is determined whether or not it is a downshift. If it is determined that it is a downshift, the process proceeds to step 180, where a predetermined downshift control routine is performed. A downshift is performed. When it is determined in steps 120 and 125 that neither an upshift nor a downshift is to be performed, the gear determined in step 110 is executed as is. According to this control flow, when the engine load is high, the gears are shifted to the highest number of gears that can be achieved (6 gears), which improves the durability of the friction material, improves fuel efficiency, and improves power performance, which are the advantages of multi-stage shifting. improvement and reduction of gear shift shock, etc., while
When the engine load is low, a four-speed gear shift control is performed, which is two gears less than this, thereby preventing the phenomenon of frequent gear changes. Since cases where the vehicle is shifted are selectively eliminated, the driver can drive more comfortably. FIG. 4 shows an example of another control flow. In this control flow, first in step 200 it is determined whether the throttle opening θ is larger than the set opening θ ₀ . If it is determined that the throttle opening θ is smaller than the set opening θ ₀ , the step
The process proceeds to step 220, where a shift pattern for low throttle opening as shown in FIG. 5 is selected. Further, if it is determined in step 200 that the throttle opening θ is larger than the set opening θ ₀ , then step 210 is performed.
Then, a high throttle opening shift pattern as shown in FIG. 6 is selected. After the gear shift pattern is selected in step 210 or step 220, the process proceeds to step 230, in which the gear position is determined in accordance with the selected gear shift pattern according to the vehicle speed and throttle opening in the main routine, and the gear position is determined in step 240. The corresponding solenoid valves are activated. The shift pattern for high throttle opening in FIG. 6 is a pattern that allows shifting in all six gears, and the shift pattern for low throttle opening in FIG. By performing only the shift corresponding to 6, the number of gears is reduced. As a result, this shift pattern for low throttle opening is a shift pattern in which the shift of the sub-transmission 18 is permitted only when the main transmission 16 is in 3rd speed, and similarly to the first embodiment, the shift pattern is There is a possibility that the shot will become larger 2
Only 1st and 4th gears are selectively removed to improve driving sensation. In the above two embodiments, when the engine load is low, the number of gears is reduced by allowing the auxiliary transmission to shift only when the main transmission is in the highest gear. The method of reducing the number of gears according to the present invention is not limited to this. For example, the sub-transmission may be allowed to shift only when the main transmission 16 is in the lowest gear. Alternatively, by combining this with the embodiments described above, a configuration may be adopted in which the sub-transmission is permitted to shift only when the main transmission 16 is in the lowest gear or the highest gear. In addition, when using the control flow as shown in FIG. In all types of multi-speed transmissions, as well as those in which the two gears are shifted simultaneously or alternately, it is possible to perform a shift that takes advantage of the multi-speed shift (depending on the engine load), while at the same time It becomes possible to perform gear shifts without feeling a busy shift. In this case, by appropriately thinning out some gears between the highest and lowest gears depending on the engine load (although the concept of simultaneous reverse gear shifting does not exist), Busy shifting can be prevented while taking advantage of the multi-speed transmission. Further, in the above embodiment, the engine load state is detected by the opening degree of the throttle valve, but the method for detecting the engine load according to the present invention is not limited to this, and for example, the engine load state is detected by the opening degree of the throttle valve. The configuration may be such that the detection is based on the intake air amount or intake pipe pressure. Further, in the above embodiments, the sub-transmission is provided on the output side of the main transmission, but in the present invention, the sub-transmission may be provided immediately at the input of the main transmission. It is clear that or,
The auxiliary gear shift may be one in which gears are set for exclusive use, or may be one such as a conventional overdrive device (low speed gear ratio is 1).

【Effect of the invention】

As explained above, according to the present invention, when the engine is in a low load state, the number of gears achieved is small, the frequency of gear changes is reduced, and comfortable driving can be achieved. In some cases, more multi-stage gear shifting can be achieved, resulting in excellent effects such as improved durability of the friction material, improved fuel efficiency, improved power performance, and reduced shift shock.

[Brief explanation of the drawing]

FIGS. 1A and 1B are block diagrams showing the gist of the present invention, and FIG. 2 is an automatic transmission with a torque converter in which an embodiment of the speed change control device for a vehicle automatic transmission according to the present invention is adopted. FIG. 3 is a block diagram showing an example of the machine, and FIG.
This figure is a flowchart corresponding to FIG. 3 showing another shift control routine, FIG. 5 is a shift pattern diagram for low throttle opening used in the shift control routine of FIG. 4, and FIG. It is also a shift pattern diagram for high throttle opening. 10... automatic transmission, 12... engine, 14
... Torque converter, 16 ... Main transmission, 18
... Sub-transmission, 20... Output shaft, 26... Hydraulic circuit for main transmission control, 28... Hydraulic circuit for sub-transmission control.

Claims (1)

[Scope of Claims] 1. A shift control device for a vehicle automatic transmission that automatically switches between a plurality of forward gears and reverse gears, comprising an engine load detection means for detecting an engine load; When the engine load is high, a first shift pattern that achieves a large number of gears is set, and when the engine load is low, the lowest and highest gears among the gears set by the first shift pattern are set. a shift pattern setting means for setting a second shift pattern that achieves a small number of gears excluding some of the gears in between; A vehicular automatic comprising: a shift execution means that executes a shift according to the first shift pattern when the load is high, and executes a shift according to the second shift pattern when the engine load is low. Shift control device for transmission. 2. A vehicle automatic in which a main transmission that achieves a plurality of forward and reverse gears and a sub-transmission that achieves low and high speed gears are connected in series and that automatically switches between the main transmission and the sub-transmission. A gear shift control device for a transmission includes an engine load detection means for detecting engine load, and a main transmission and an auxiliary transmission that are connected to the engine load and are connected to the main transmission and the sub transmission between the lowest gear and the highest gear when the engine load is high. A first shift pattern is set that achieves a large number of gears, including a gear that is achieved by shifting simultaneously in opposite directions, and when the engine load is low, the gears set by the first gear shift pattern are set. A second gear shifter that achieves a reduced number of gears excluding the gearshift achieved by simultaneously shifting at least the main transmission and the sub-transmission in opposite directions.
and a shift pattern setting means for setting a shift pattern, and based on the engine load detected by the engine load detection means, when the engine load is high, the shift is executed according to the first shift pattern, and the engine load is reduced. A shift control device for an automatic transmission for a vehicle, comprising: a shift execution unit that executes a shift according to the second shift pattern when the gear shift is low.