JPH11351368A - Shift controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the shift controlling constant according to the load of a vehicle to improve the shifting feeling in a shift controller for an automatic transmission, and reduce the development manpower for the automatic transmission. SOLUTION: This controller is provided with a vehicle load degree calculating means 2 for calculating the load degree acting on a traveling vehicle, a shifting constant setting means for dividing the vehicle load degree into a plurality of load areas and setting the shift control constant every load area, and a shifting control means 71 for performing a shift control. In changing the speed position, the shift control is performed on the basis of the shift control constant set by the shift constant setting means 10 on the basis of the vehicle load degree.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shift control device for an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, various shift control constants have been set in a shift control device of an automatic transmission applied to a vehicle or the like, and the shift control is executed using the shift control constants during shift control. Is done. Here, the shift control constant refers to, for example, a time from when a shift instruction is output to when the engine torque is reduced, a time from when the shift speed is changed to when the engine torque is restored, or an engine speed is changed. Of the rack position of the fuel injection pump at that time.

[0003]

However, in the conventional automatic transmission, a shift shock may occur at the time of gear shifting if the road surface gradient or the load capacity of the vehicle greatly changes. For example, in an automatic transmission in which each shift control constant is set mainly in consideration of shift control on a flat road, a shift shock occurs on an uphill road or a downhill road because the running state of the vehicle is different from that on a flat road. It is.

For this reason, when determining the shift control constant, a running test is repeatedly performed in consideration of various road gradients and running conditions, and the shift shock is reduced on average in any running condition. Although the transmission control constant has been set as described above, such a method has a problem that it takes a lot of time to develop and test the automatic transmission. Further, in a vehicle such as a tractor that runs by towing a trailer, the load on the vehicle greatly changes depending on the connected state and the loaded state of the trailer. Therefore, the shift shock described above becomes remarkable depending on the load state of the vehicle. For this reason, there is a demand for an automatic transmission applied to such a vehicle to reduce a shift shock by changing a shift control constant according to a load state (different from an engine load based on an accelerator opening).

Japanese Patent Application Laid-Open No. 9-79364 discloses that
A technology has been disclosed in which a load acting on a vehicle is calculated and shift control is performed in accordance with the vehicle load by fuzzy control. However, this technology eliminates shift shock by changing a shift control constant. It wasn't the technology to do it.
In addition, there is a type in which a certain shift control constant is changed in accordance with an accelerator opening, an engine speed, and the like to perform a shift control in accordance with a traveling state of a vehicle. It was not able to cope sufficiently and could not solve the above-mentioned problems.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is possible to improve a shift feeling by changing a shift control constant in accordance with a degree of load of a vehicle, and to reduce the man-hour for developing an automatic transmission. It is an object of the present invention to provide a shift control device for an automatic transmission as described above.

[0007]

In the transmission control apparatus for an automatic transmission according to the present invention, a load degree acting on a running vehicle is calculated by a vehicle load degree calculation means.
The shift constant setting means divides the vehicle load into a plurality of load areas according to the calculation result of the vehicle load calculating means, and sets the shift control constant of the automatic transmission set for each of the load areas. Is output. Then, when the gear position is changed, the shift control unit executes the shift control using the shift control constant set by the shift constant setting unit.

According to a second aspect of the present invention, there is provided a shift control device for an automatic transmission, wherein a towing state of the vehicle is detected by the towing state detecting means, and a shift constant setting means includes:
Based on the detection information from the towing state detection means, the division of the load area of the vehicle load degree between the towing state and the non-towing state is changed, and a shift control constant is set in consideration of the towing state of the vehicle.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram showing a main part of an automatic transmission according to an embodiment of the present invention; FIG. FIG. 6A is a diagram illustrating an example of setting of control constants, where FIG. 7A is a diagram specifically illustrating a division of a load region, and FIG.
FIG. 3 is a diagram specifically showing the division of the load region when the vehicle is in a tow state, FIG. 3C is a diagram specifically showing the division of the load region when the vehicle is in a tow state, and FIG. 7A and 7B are time charts for explaining, in which FIG. 7A is a diagram illustrating characteristics of a rack designated position during gear shift control, and FIG. 7B is a diagram illustrating characteristics of an engine speed and a clutch speed during gear shift control.

In this embodiment, a description will be given of a case where a mechanical automatic transmission is used as an automatic transmission that automatically shifts gears using a gear mechanism and a clutch mechanism similar to those of a manual transmission. The structure of the mechanical automatic transmission is already known, and a detailed description thereof will be omitted. Further, in the present embodiment, a case will be described in which a tractor that can run by connecting a vehicle such as a trailer is used as the vehicle.

As shown in FIG. 1, the automatic transmission according to this embodiment includes a control unit (shift control means) 7.
The control unit 71 sets the target shift speed. The control unit 71 includes target gear position setting means 3 for setting a target gear position based on vehicle speed information V from a vehicle speed sensor 79 and accelerator opening information VA from an accelerator opening sensor (accelerator opening detecting means) 85. Is provided.

Here, the target gear position setting means 3 is provided in a usual manner.
A shift map widely used for automatic transmissions,
Accelerator opening information VA detected by cell opening sensor 85
And vehicle speed information V detected by the vehicle speed sensor 79.
To set the target shift speed. Also shown in FIG.
As described above, the control unit 71 includes the vehicle load
Degree α _VLVehicle load degree calculation means 2 for calculating the
Have been. In addition, the vehicle load by the vehicle load degree calculating means 2
Degree α_VLThe calculation method of is described in JP-A-9-79364.
It is almost the same as that described in the gazette,
Bottom, easy vehicle load α _VLThe calculation method of
You.

The vehicle load degree calculating means 2 includes an engine torque calculating means 4, a driving force calculating means 5, an air resistance calculating means 6, an acceleration calculating means 7 corresponding to a straight flat road and an empty vehicle, and a subtracting means 8. . The engine torque calculating means 4 is an engine (here, a diesel engine).
As shown in FIG. 1, the control rack position information (engine output instruction information) SRC from the rack position sensor 123 and the engine speed information NE from the engine speed sensor 27 are calculated as shown in FIG. Based on this, the output engine torque T is calculated.

The driving force calculating means 5 calculates the driving force F of the vehicle based on the engine torque information T obtained by the engine torque calculating means 4, and the air resistance calculating means 6 calculates the vehicle speed. The air resistance Rl as the running resistance of the vehicle is calculated from the actual vehicle speed information V detected by the sensor 79. In addition, acceleration calculating means (hereinafter, sometimes simply referred to as acceleration calculating means) equivalent to a straight flat road and empty vehicle 7
The acceleration (hereinafter, referred to as the acceleration when the vehicle accelerates on a straight flat road in an empty state) is obtained from the driving force information F calculated by the driving force calculation unit 5 and the air resistance information Rl calculated by the air resistance calculation unit 6. This is referred to as acceleration on a straight flat road.
₀ is calculated.

The subtraction means 8 reduces the load degree information α _VL of the vehicle based on the acceleration information α ₀ calculated by the acceleration calculation means 7 corresponding to the straight flat road and the vehicle and the actual acceleration information α from the vehicle speed sensor 79. It is calculated by an equation. α _VL = α ₀ −α Then, from the magnitude of the value of α _VL , it is determined how high (or low) the vehicle load is.

Next, the main parts of the present invention will be described.
As shown in FIG. 1, in the present device, a shift constant setting means 10 for setting a shift control constant of an automatic transmission is provided in a control unit 71. Here, the shift control constant is a numerical value set for operating an engine, a clutch, a transmission, or the like in a predetermined manner during shift control,
In the present embodiment, among such shift control constants, the engine torque reduction instruction time E0 at the start of the shift control, the engine torque return instruction time E1 before the end of the shift control, the engine speed at the time of clutch engagement after the shift stage is switched Three shift control constants of the correction value N are set by the shift constant setting means 10.

As shown in FIG. 1, vehicle speed information is input to the speed change constant setting means 10 via the vehicle load degree calculation means 2.
Then, the three shift control constants are set using the vehicle load _αVL as a parameter. Specifically, a table in which the vehicle load degree is divided into a plurality of regions is provided in the shift constant setting means 10, and a shift control constant is set for each of these load regions. . Then, the shift constant setting means 10 determines the current load area based on the vehicle load degree α _VL input from the vehicle load degree calculating means 2 and outputs the shift control constant set in this load area. It is becoming.

On the other hand, this vehicle is provided with a trailer switch (towing state detecting means) 11 for detecting the towing state of the vehicle. The trailer switch 11 can detect whether the vehicle is connected to a trailer (referred to as a towed state or a connected state) or is not connected to a trailer (referred to as a non-towed state or a single vehicle state). A sensor, as shown in FIG.
1 is connected to the shift constant setting means 10. The trailer switch 11 described above is configured as a switch that works in conjunction with a brake hose cock when, for example, a tractor-side service brake is connected to a trailer-side service brake.

The transmission constant setting means 10 detects the detection result from the trailer switch 11 (trailer connection information).
, The setting of the division of the load area is changed between when the vehicle is connected and when the vehicle is single vehicle. That is, in the shift constant setting means 10, as shown in FIG. 2A, the division of the load region is set, and the shift control constant is set for each of these load regions.

A specific description will be given below with reference to FIGS. 2A to 2C. First, when the trailer switch 11 detects that the vehicle is in a single vehicle state, FIG.
(A), (b), the vehicle load of alpha _VL is the first predetermined value alpha ₁ is smaller than the first area and (negative region), vehicle load of alpha _VL is the first predetermined value alpha The second predetermined value α ₂ which is ₁ or more
A second region (intermediate region), which is smaller, and a third region (high region) in which the vehicle load α _VL is equal to or more than a _second predetermined value α _2.
The vehicle load region is divided into two regions. In the above-described embodiment, α ₁ = 0.

[0021] Then, for each of these load range, said shift control constants E0, E1, respectively as N (E0 _1, E
_{1 1, N 1) ~ (} E0 3, E1 3, N 3) is set. When the trailer switch 11 detects that the vehicle is connected, FIG.
As shown in (c), the vehicle load degree α _VL becomes the third predetermined value α
₃ (in the present embodiment, α ₃ = α ₁ = 0), a fourth area (negative area) smaller than the vehicle load degree α _{VL and a} third predetermined value α
_A fifth region (intermediate region) that is equal to or more than _{3 and is} smaller than the _fourth predetermined value α4, and a sixth region where the vehicle load _αVL is equal to or more than the _fourth predetermined value α4.
The vehicle load region is divided into three regions of a region (high region).

Further, similarly to the case of the single-vehicle state, also in the case of this connection state, the above-mentioned shift control constant E for each load region.
0, E1, respectively as _{N (E0 4, E1 4,} N 4)
_{~ (E0 6, E1 6,} N 6) is set. At the time of shifting, shift control is performed using a shift control constant corresponding to the vehicle load degree α _VL , whereby a wide range shift shock is generated regardless of the running state of the vehicle or the road surface gradient. It is reduced.

In this embodiment, the first predetermined value α ₁
And the third predetermined value α ₃ are set to the same value,
The fourth predetermined value α ₄ is set to be larger than the second predetermined value α ₂ , and is set such that the intermediate range is wider in the connected state than in the single vehicle state. The settings can be changed as needed. next,
Each shift control constant E0, E in the shift constant setting means 10
The tendency of the setting of 1 and N will be briefly described. First, the shift control constant E0 will be described. As described above, the shift control constant E0 is the engine torque reduction instruction time at the start of the shift control, and specifically, the engine torque decrease instruction time at the start of the shift control. This is the time between the output of the instruction and the start of the gear disengagement of the gear currently engaged (see FIG. 3A).

The reason why the engine torque is reduced before the shift to the target shift speed is that if a large torque is applied to the gear mechanism of the transmission at the time of switching to the target shift speed, the engine is currently engaged. This is because it is difficult to disengage the gear, and the gear is easily disengaged by reducing the engine torque before switching to the target shift speed.

When the vehicle is traveling on an uphill road where the vehicle load is high, the rate of decrease in the vehicle speed during the shifting operation is greater than during traveling on a flat road as an intermediate region. If the same shift control constant E0 as that for a flat road is used, it is considered that the vehicle speed is excessively reduced by the time the gearshift starts and a shift shock occurs when the clutch is engaged. Therefore, the engine torque reduction instruction time E0 ₃ high areas (or, E0 _6), the value of the intermediate region E0 ₂ (or, E0 ₅₎ is set to a value smaller than promptly reduce engine torque It is set to let.

Further, on the contrary, in the region of low load slope such descending, the rate of decrease in the vehicle speed during the shift operation is small, the engine torque reduction instruction time this area E0 ₁ (or, E0 ₄₎ is , the value of the intermediate region E0 ₂ (or, E0 ₅₎ is set to a value greater than equal to or with. Therefore, the engine torque reduction instruction time E0 in each load _{range, E0 3 ≦ E0 2 ≦ E0} 1 ( at motorbike) or E0
₆ ≦ E0 ₅ ≦ E0 ₄ are set so that (connection time).

Next, the shift control constant E1 will be described. The shift control constant E1 is the engine torque return instruction time before the end of the shift control, and the engine torque is restored after the clutch is connected after the gear change is completed. 3 until the shift control is completed.
(A)]. At the time of shifting during traveling on an uphill road, which is considered to be representative of a region where the vehicle load is high, the vehicle speed decreases in a shorter time than when shifting on a flat road as representative of the intermediate region as described above. Therefore, in order to end the shift control without causing a shift shock, it is necessary to quickly return the engine torque after the gear change is completed. Therefore, the engine torque return instruction time area of the vehicle load of high E1 ₃ (or, E1 _6), the value of vehicle load of the intermediate region E1 ₂ (or, E1 ₅₎ is set to a value smaller than.

Conversely, in a low-load area such as a downhill road (a region where the vehicle load is negative), the rate of decrease in vehicle speed during gear shifting is relatively small. time E1 ₁ (or, E1 _4), the value of vehicle load of the intermediate region E1 ₂ (or, E1 ₅₎ is set to a value greater than equal to or with. Therefore, the engine torque return instruction time E1 in each load region, the same tendency as the engine torque reduction instruction time E0 above, _{i.e., E1 3 ≦ E1 2 ≦ E1} 1 ( at motorbike), or E1 ₆ ≦
It is set so that E1 ₅ ≦ E1 ₄ (when connected).

Finally, the shift control constant N will be described. The shift control constant N is an engine speed instruction value at the time of completion of the gear change (at the completion of gear shifting).
This is the amount of increase in the engine speed relative to the engine speed at the time of completion of gear shifting (see FIG. 3A). At the time of shifting in the region where the vehicle load is high, the engine speed instruction value N ₃
(Or N ₆ ) is changed to the value N ₂ (or N
₅ ) The shift shock is suppressed as much as possible by setting a value smaller than that of the engine speed instruction value N ₁ (or, in the negative vehicle load range).
By setting N ₄ ) equal to or greater than the value N ₂ (or N ₅ ) in the intermediate range, shift shock on a downhill road is suppressed.

That is, for the engine speed instruction value N, N ₃ ≦ N ₂ ≦ N ₁ (for a single vehicle) or N ₆ ≦ N ₅
≦ N ₄ (at the time of connection). In addition,
There are various types of shift control constants other than those described above.
It is not limited to only these three constants.
Further, in the present embodiment, the other shift control constants other than those described above are stored as fixed values in a memory (not shown) in the control unit 71. It may be changed according to the vehicle load degree _αVL .

Since the shift control device for an automatic transmission according to one embodiment of the present invention is configured as described above, for example, the vehicle load degree is calculated and shift control is executed as follows. You. First, the calculation of the vehicle load degree α _VL will be described. First, the engine torque T is calculated by the engine torque calculating means 4 based on the position information SRC of the control rack and the engine speed information NE. The driving force calculating means 5 calculates the driving force F of the vehicle based on the engine torque T, the gear ratio it of the shift speed, the final reduction gear ratio (final reduction gear ratio) if, the power transmission efficiency η, and the tire radius R determined by the above. Is calculated.

The air resistance calculating means 6 calculates the air resistance Rl of the vehicle based on the air resistance coefficient λ, the front projected area A of the vehicle, and the vehicle speed V. Then, the straight flat road empty vehicle equivalent acceleration calculation means 7 calculates the straight flat road empty vehicle equivalent acceleration α ₀ from the driving force F and the air resistance information Rl, and calculates the straight flat road empty vehicle equivalent acceleration information α ₀ and the vehicle speed sensor. The load degree information _{αVL of the} vehicle is calculated based on the actual acceleration information α from 79 and output to the shift setting means 10.

Next, the target shift speed setting means 3 sets the target shift speed from the shift map based on the vehicle speed V and the accelerator opening VA in accordance with the running state. On the other hand, when the connected state of the trailer is detected by the trailer switch 11, the shift setting means 10 sets the trailer switch 11
And the load degree information α calculated as described above.
Based on _VL , the engine torque reduction instruction time E0 at the start of the shift control, the engine torque return instruction time E1 before the end of the shift control, and the engine rotational speed correction value N at the time of clutch engagement after the shift stage is switched are calculated. Set two transmission control constants. At the time of shift control, shift control is performed using these shift control constants.

That is, in the speed change setting means 10, FIG.
As shown in (a), the vehicle load degree is divided into three regions, and the division setting of the vehicle load degree region is changed according to the connection state of the vehicle. The vehicle load of alpha _VL and set control constants to each area in accordance with the connection state of the vehicle _{(E0 1, E1 1, N} 1) ~ (E0 6, E1 6, N 6)
Is output.

As described above, the driving state of the vehicle is divided into six regions according to the degree of vehicle load, and the shift constant is set for each of the regions. As a result, fine shift control is executed, and the occurrence of shift shock is reduced as much as possible. Hereinafter, a specific example of the shift control performed by the shift control device for the automatic transmission according to the present invention will be described with reference to FIGS. FIGS. 3 (a) and 3 (b) show the case where the upshift is performed during acceleration on a flat road as the middle area of the vehicle load, and the case where the upshift is performed during acceleration on the uphill road as the area with the high vehicle load. For each of the cases
9 shows the characteristics of a rack indication position and changes in the rotation speeds of an engine and a clutch. Further, in the drawing, the solid line indicates the characteristic when traveling on an uphill road, and the broken line indicates the characteristic when traveling on a flat road. Further, in the following description, it is assumed that the trailer switch 11 detects that the vehicle is in a non-traction state (in a single vehicle).

First, based on information from the vehicle load degree calculation means 2 and the trailer switch 11, the vehicle is in a non-traction state (single vehicle state) and the load degree α _VL is in the medium load region (here, If it is determined that a flat road travel is equivalent), the shift control constants in the shift constant setting means 10 based on the information (E0, E1, N) each value of the second region (E0 _2, E1 _2, N ₂ ).

[0037] Then, FIG. 3 (a), as indicated by a broken line in (b), t = the shift control at t ₁ is started, the shift constant setting means 10 the engine torque reduction instruction time set by E0 ₂ During (t = t _{1 to} t ₂ ), the rack position is reduced to a predetermined value to suppress the engine torque. During this time, the clutch is disengaged, and the clutch rotation speed becomes higher than the engine rotation speed.

Thereafter, during the period from t = t ₂ to t ₃ , the gear is removed from the current gear and the gear is shifted to the target gear to complete the gear switching. In addition, since the gear ratio becomes smaller at the time of such an upshift, the rotation speed of the clutch is reduced at the completion of the gear shifting, and the engine rotation speed is relatively higher than the clutch rotation speed. At the time of completion of gear shifting (t = t ₃ ), the rack position is increased by the engine speed instruction value N ₂ to increase the engine speed.

At this time, the clutch is connected almost simultaneously.
Start operation. And t = t_FourAt the clutch
When the joining is determined, it is set by the shift constant setting means 10.
Engine torque return instruction time E1_Two(T = t_Four~
t_Five) Gradually increase the rack position during
Luke is restored. Well, on the contrary, the vehicle
Based on the information from the load calculation means 2, the vehicle load degree α_VL
Is in the high region (here, it is equivalent to traveling uphill)
Is determined, the shift control constants (E0, E1, N) are
The value of the third area (E0_Three, E1_Three, N _ThreeSet to
Is done. Note that these control constants (E0_Three, E1_Three, N
_Three) Are for the medium load range, as described above.
Constant (E0_Two, E1_Two, N_Two) Set smaller than the value
Have been.

[0040] Then, as shown by the solid line in FIG. 3 (a), (b) , t = the shift control is started at t _1, after the engine torque decrease instruction time E0 ₃ from the t ₁ t =
Changes rack indication position until t ₂ is executed, t =
gear vent is started at t _2. Here, since the control constant E0 ₃ is set smaller than the control constant E0 ₂ of the second region, will be promptly engine torque is suppressed.

Note that t ₁ to t in the third region
₂ (that is, E0 ₃ ) and the time from t ₁ to t ₂ (that is, E0 ₂ ) in the above-described second region are different from each other. as shown in (b), t ₁ ~t ₅ is a mean operation timing in both simply shift control does not indicate a physical time.

When the shift control is started, the clutch is disengaged by the time of starting the gear disengagement (t = t ₂ ). Thereafter, the gear disengagement of the current gear and the gear shift to the target gear are executed. The gear change is completed (t = t ₃ ). At this time, the timing of the completion of the gear shifting is earlier than the time of the shift in the second region by the amount of the prompt execution of the suppression of the engine torque.

When the gear is completely engaged (t = t ₃ ), the rack position is increased by the engine speed instruction value N ₃ to increase the engine speed. here,
Since the control constant N ₃ is set smaller than the control constant N ₂ in the second region, the increase in the engine speed is suppressed more than in the second region.

Then, when the clutch engagement is determined at t = t ₄ , the engine torque return instruction time E
1 increasing rack position between _{3 (t = t 4 ~t 5} ),
The engine torque is restored. Again, since the control constants E1 ₃ described above is set to be smaller than the control constants E1 ₂ of the second region, will be promptly torque return is performed.

Therefore, in the shift control in the third area (the area where the vehicle load is high), the shift time is shortened as a whole as compared with the shift control in the second area (the area where the vehicle load is high). become. In particular, traveling on an uphill road (representative mode of the third area)
In the prior art, a shift shock may occur in the prior art because the rate of decrease in vehicle speed during shifting is greater than in flat road driving (representative mode of the second area). Accordingly, a decrease in vehicle speed during shifting is also suppressed, so that shift shock can be reduced.

Further, as described above, the load of the vehicle is calculated in consideration of parameters other than the road surface gradient, and the shift control constant is set in accordance with the load. In addition, shift shock during shifting can be suppressed in a wide range. On the other hand, in the prior art, when determining the shift control constant, a running test is repeatedly performed in consideration of various road gradients and running conditions, and an average shift shock is small in any running state. Since the shift control constants were set to be as follows, it took a lot of time to develop and test the automatic transmission. However, according to the shift control device for an automatic transmission of the present invention, such development man-hours are also reduced. Thus, the cost of the automatic transmission can be reduced.

Further, in a vehicle towing a trailer or the like, a region of the vehicle load degree is set in consideration of the towing state of the trailer or the like, and a shift control constant in each region is set. In a vehicle in which the total weight of the vehicle fluctuates significantly when the trailer is being pulled, the shift shock is greatly reduced. Also, in the above embodiment,
Although the vehicle load degree is divided into three load regions, and the setting of the load region is changed according to the towing state of the vehicle (see FIG. 2A), the automatic transmission according to the present invention is provided. The division setting of the load region in the shift control device of the present invention is not limited to this, and the division of the load region may be changed as needed.

Further, in this embodiment, a case has been described in which a mechanical automatic transmission is used as the automatic transmission.
The present invention can be applied not only to such a mechanical automatic transmission but also to a general automatic transmission in which a torque converter and a planetary gear mechanism are combined, and also to various automatic transmissions. be able to. In the above embodiment, the case where the diesel engine is used as the engine has been described. However, the present invention can be applied to a gasoline engine. In this case, the engine speed control based on the engine speed correction value N may be executed based on a throttle opening instruction instead of a rack position instruction.

[0049]

As described above in detail, according to the shift control device for an automatic transmission according to the present invention, the vehicle load degree is divided into a plurality of load regions, and each of the vehicle load regions is divided into a plurality of load regions. Since the shift control is performed based on the set shift control constants, there is the advantage that shift shock during shifting can be suppressed in a wide range regardless of the load state or running state of the vehicle, and the development and testing of automatic transmissions The number of development steps required for the automatic transmission can be reduced, and the cost of the automatic transmission can be reduced.

According to the shift control apparatus for an automatic transmission according to the second aspect of the present invention, the shift control constant is set in consideration of the connection state of the vehicle, so that the total weight varies greatly. The vehicle has an advantage that the effect of reducing shift shock is particularly large.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a main configuration of a shift control device for an automatic transmission according to an embodiment of the present invention.

2A and 2B are diagrams illustrating an example of setting of a shift control constant in a shift control device for an automatic transmission according to an embodiment of the present invention, wherein FIG.
FIG. 4B is a diagram specifically illustrating the division of the load region when the vehicle is in the non-traction state, and FIG. 4C is a diagram specifically illustrating the division of the load region when the vehicle is in the towing state.

3A and 3B are time charts for explaining an operation of the shift control device for the automatic transmission according to the embodiment of the present invention, wherein FIG. 3A is a diagram illustrating characteristics of a rack pointing position at the time of shift control; FIG. 6B is a diagram illustrating characteristics of the engine speed during the shift control.

[Explanation of symbols]

 2 Vehicle load degree calculation means 11 Trailer switch as towing state detection means 10 Shift constant setting means 71 Control unit as shift control means

Claims (2)

[Claims] 1. A shift control device for an automatic transmission capable of automatically changing a gear position according to a driving state of a vehicle, wherein a vehicle load degree calculating means for calculating a load degree acting on the running vehicle; Shift constant setting means for dividing the vehicle load degree into a plurality of load areas according to a calculation result of the vehicle load degree calculation means and setting a shift control constant of the automatic transmission for each of the load areas; A shift control unit for performing a shift control based on a shift control constant set by the shift constant setting unit when a shift stage is changed. 2. The vehicle according to claim 1, further comprising: a towing state detecting unit configured to detect a towing state of the vehicle, wherein the shift constant setting unit determines whether the vehicle is in a towing state or a non-towing state based on detection information from the towing state detecting unit. 2. The apparatus according to claim 1, wherein the setting is made so as to change the load area division of the load degree.
A shift control device for an automatic transmission according to claim 1.