JPH1182676A - Speed change control device for vehicular transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed change control device for a vehicular transmission, which secures the function of an engine brake when a vehicle is abruptly decelerated, prevents the occurrence of engine stall and knocking, and also prevents acceleration responsiveness from being degraded at the time of reacceleration. SOLUTION: When a vehicle is abruptly decelerated, let the swash plate angle of a hydraulic motor be 1/3 of that of a normal operation, and let a stroke for the swash plate angle of a hydraulic pump be 1/3 of that of a normal operation. By this constitution, the responsiveness of the swash plate of the liquid operated motor is enhanced, the change of a stroke for the swash plate of the hydraulic pump when the vehicle is abruptly decelerated can be followed to the change of vehicle speed, the occurrence of troubles such as engine stall and the like caused by the delay in response, can be prevented, and the delay in response at the time of reacceleration can also be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a vehicle transmission mounted on a passenger car, truck or other traveling vehicle, and more particularly, to a hydromechanical transmission (HMT). The present invention relates to a shift control device for a vehicle transmission provided with a continuously variable transmission. This HMT is a hydrostatic transmission (hereinafter referred to as “HS”) that utilizes the static pressure energy of a fluid.
T ”) and mechanical transmissions (Mechanic
al. Transmisson (hereinafter referred to as "MT") through a planetary gear mechanism so as to continuously and continuously change gears.

[0002]

2. Description of the Related Art Conventionally, as this type of continuously variable transmission, US Pat. No. 4,341,131 or
One proposed in Japanese Patent Application Laid-Open No. 54-55560 is known. In the continuously variable transmission disclosed in these publications, the MT and the HST are combined, and the relation of each gear ratio of the planetary gear mechanism provided therein is set to specific conditions, and
Three operation modes (first mode, second mode and third mode)
Mode) when driving in each mode
Shift control is performed by changing the angle of a swash plate of a hydraulic pump provided in the HST.

In general, in the HMT, the variable swash plate of the hydraulic pump of the HST is controlled to be changed into three operation modes in accordance with the speed ratio of the HMT. The system is designed such that the rotation of a constant number of revolutions input to the input shaft of the HMT is transmitted to the output shaft of the HMT by continuously and continuously changing the number of revolutions. The speed ratio of the HMT means output shaft rotation speed (No) / input shaft rotation speed (Na).

That is, in each of the three operation modes of the first mode, the second mode, and the third mode, the HMT is controlled by controlling the displacement of the hydraulic pump and the hydraulic motor.
Is controlled such that the speed ratio of the motor continuously changes steplessly.

Further, in recent years, the efficiency of the entire continuously variable transmission has been improved by improving the efficiency in a low speed ratio range, and the capacity of the hydraulic pump has been reduced and the no-load loss has been reduced. In order to reduce the size and weight of the continuously variable transmission and to improve the efficiency at a low load, a continuously variable transmission that can be operated by dividing the entire speed ratio range into four modes has been developed.

Hereinafter, the structure of the HMT (2) which can be operated in these four modes will be described with reference to FIG.

[Configuration of HMT] This HMT (2) has an input shaft (2) for receiving a rotation input from an engine (not shown).
1) and an output shaft (2) connected to a drive wheel (not shown).
2), an MT (4) provided between the input shaft (21) and the output shaft (22), and the MT (4) is disposed in parallel with the MT (4). ) And an HST as a hydrostatic transmission connected on the output side to the output shaft (22) via the MT (4).
(5).

The HMT (2) further includes a third planetary gear mechanism (23) for reducing an input rotation from an engine (not shown) and a rotation reduced by the third planetary gear mechanism (23). A fourth clutch mechanism (24) as a transmission clutch for transmitting to MT (4), and an input rotation input to third planetary gear mechanism (23) as is (4).
And a fifth clutch mechanism (25) as a transmission clutch for transmitting to the transmission.

[Configuration of MT] MT (4) is arranged coaxially with a first planetary gear mechanism (41), a second planetary gear mechanism (42), an input shaft (21) and an output shaft (22). Intermediate shaft (43), and first and second planetary gear mechanisms (41,
42) first to third three clutch mechanisms (44, 45, 4) as shift clutches for switching the operation conditions.
6), and a fourth and fifth clutch mechanism (24, 25) and a third planetary gear mechanism (23) are provided on the input side of the MT (4). Hereinafter, each mechanism will be described in detail.

The first planetary gear mechanism (41) includes a first sun gear (41a), a first planetary gear (41b) meshing with the first sun gear (41a), and a first planetary gear (41).
1) includes a first internal gear (41c) meshing with b) and a first carrier (41d) holding the first planetary gear (41b).

The second planetary gear mechanism (42) includes a second sun gear (42a) formed on the intermediate shaft (43) and a second planetary gear (4) meshing with the second sun gear (42a).
2b) and a second planetary gear (42b) meshing with the second planetary gear (42b).
An internal gear (42c) and a second carrier (42d) for holding the second planetary gear (42b) are provided.

The first sun gear (41a) has an output shaft (2).
A tubular connecting shaft (4) externally rotatable relative to 2).
1e) and is integrally formed with the gear (41f), and is connected to the motor shaft (52a) of the hydraulic motor (52) via the gear (41f) and a gear (56) described later. ing.

The first carrier (41d) includes a tubular member (4).
7), and a second internal gear (42c) is formed on an inner peripheral surface of the tubular member (47), whereby the first carrier (41d) and the second internal gear (42c) are formed. )
Rotate in synchronization with each other.

The first internal gear (41c) is a jaw-shaped member (41).
g), and a second carrier (42d) is attached to the jaw member (41g). The jaw (41g) is integrally attached to the output shaft (22), so that the second carrier (42d) is connected to the first carrier (42d).
It is configured to rotate in synchronization with the internal gear (41c), and to couple the first internal gear (41c) and the second carrier (42d) to the output shaft (22).

The first clutch mechanism (44) includes a plurality of clutch plates (44a, 44a,...) Mounted around the tubular member (47) and a plurality of pressure plates sandwiching each of the clutch plates (44a). Plate (44
b, 44b,...). Each pressure plate (44b) is fixed to a non-rotating portion (26), which is a casing (not shown) of the HMT (2), in a state where relative rotation is prevented, whereby the first clutch mechanism (44). Can connect and disconnect the first carrier (41d) and the second internal gear (42c) to and from the non-rotating part (26) by applying a braking force to the tubular member (47) in a connected state. To be connected to.

The second clutch mechanism (45) has an intermediate shaft (4).
3) A plurality of clutch plates (4) attached around
5a, 45a,...) And a plurality of pressure plates (45b, 45a) attached to the inner peripheral surface of the tubular member (48).
b,...). The tubular member (48) can be connected to the input shaft (21) via the third planetary gear mechanism (23) by intermittent switching of the fourth clutch mechanism (24). The mechanism (45) transmits the rotation input from the connected fourth clutch mechanism (24) to the second sun gear (42a) in an intermittently switchable manner.

The third clutch mechanism (46) is provided on a plurality of clutch plates (46a, 46a,...) Mounted around the tubular member (47) and on the inner peripheral surface of the tubular member (48). Pressure plate (46b, 46b,
..), Whereby the rotation input to the first carrier (41d) and the second internal gear (42c) from the connected fourth clutch mechanism (24) can be switched on and off. introduce.

The third planetary gear mechanism (23) has an input shaft (2).
A third sun gear (23a) fixed side by side with a gear (49) described later with respect to 1), and the third sun gear (23a)
And a third planetary gear (23b) meshed with the third planetary gear (23b) and fixed to the non-rotating portion (27) as a casing in a state where relative rotation is prevented.
An internal gear (23c) and a third carrier (23d) for holding a third planetary gear (23b) are provided.

Each gear (23) of the third planetary gear mechanism (23)
a, 23b, 23c) reduce the input rotation of the input shaft (21) input to the third sun gear (23a) at a predetermined reduction ratio as described later and rotate the third carrier (23d). Number settings have been made.

The fourth clutch mechanism (24) is provided on a plurality of clutch plates (24a, 24a,...) Mounted on the outer periphery of the third carrier (23d) and on the inner peripheral surface of the cylindrical member (48). Pressure plates (24
, 24b,...), and the third planetary gear mechanism (2) is connected to the cylindrical member (48) on the input end side of the second and third clutch mechanisms (45, 46).
The rotation decelerated by 3) is transmitted.

The fifth clutch mechanism (25) is connected to the input shaft (2
1), a plurality of pressure plates (25b, 25b,...) Provided on the inner peripheral surface of the tubular member (25a), and an intermediate shaft (4).
A plurality of clutch plates (2) provided around the outside of (3)
5c, 25c,...) And the second sun gear (42a) via the intermediate shaft (43) by being connected.
And the input shaft (21), and the rotation of the input shaft (21) is directly transmitted to the second sun gear (42a).

In the MT (4) having the above structure, the gear ratio of each element of the first and second planetary gear mechanisms (41, 42) and the reduction ratio by the third planetary gear mechanism (23) are as follows. Thus, a substantially continuous transmission ratio is provided before and after switching between four operation modes of first to fourth modes described later.

That is, as shown in the planetary velocity diagram of FIG. 6, the first sun gear (41a) and the first internal gear (41c).
When the gear ratio between the second sun gear (42a) and the second internal gear (42c) is X, the relation Y = X + 1 is established. And the reduction ratio of the third planetary gear mechanism (23) is Y /
The value is set to be a value represented by (2X + Y + 2).

The gear ratio X is set to approximately 2 and the gear ratio Y is set to approximately 3. Therefore, the third planetary gear mechanism (23)
Is set to approximately 1/3, whereby when the input rotation of the rotation speed (Ni) is input from the engine (1), the speed is reduced by the third planetary gear mechanism (23). The rotation speed Nir satisfies the relationship of Nir = Ni / 3. In the planetary speed diagram, the abscissa indicates the gear ratio of each element of the first and second planetary gear mechanisms (41, 42), and the ordinate indicates the rotational speed of each element. It is a thing.

[Structure of HST] On the other hand, HST (5)
Referring again to FIG. 5, a pair of hydraulic units (51, 52) having substantially the same configuration are connected to a pair of communication pipes (53a, 53).
b) to form a closed circuit (53)
The input-side hydraulic unit (51) to which the rotational force from the engine (not shown) is input is called a hydraulic pump, and the output-side hydraulic unit (52) to which the rotational force after shifting is output is a hydraulic motor. Is what you call.

Although not shown, the hydraulic pump (51) includes a cylinder block that rotates integrally with the pump shaft (51a) via a spline, and a circumferential centered around the pump shaft (51a) inside the cylinder block. A variable swash plate type piston pump including a plurality of reciprocating pistons housed in a row at an upper position, wherein the reciprocating process of these pistons is changed and adjusted by a variable swash plate (51b).

The gear (5) connected to the pump shaft (51a)
4) is meshed with the gear (49) of the input shaft (21), whereby torque from the engine (1) is input to the pump shaft (51a).

The variable swash plate (51b) has a swash plate angle of 0 °.
The swash plate angle is maximum across the neutral position (for example, 1
7 °) between the maximum rotation position on both the forward rotation side and the reverse rotation side.
Is tilted by a hydraulic pump swash plate angle change adjusting device (55) which operates in response to an operation signal from the swash plate to increase or decrease the swash plate angle. The hydraulic pump swash plate angle changing and adjusting device (55) is constituted by, for example, an actuator that is operated by pressure oil, and receives an operation signal from a controller (not shown) and receives an operating hydraulic pressure from a control auxiliary pump (not shown). Is introduced, whereby the variable swash plate (51b) is tilted.

The hydraulic pump (51) has a pump shaft (51).
By rotating a) by the input from the engine, each piston is rotated around the pump shaft (51a) together with the cylinder block, and the piston is substantially proportional to the inclination angle of the variable swash plate (51b). The hydraulic motor (52) is configured to reciprocate, discharge hydraulic oil at a flow rate corresponding to the swash plate angle by reciprocating the piston, and interpose one of the communication pipes (53a or 53b).
Side.

Although not shown, the hydraulic motor (52) has a cylinder block that rotates integrally with the motor shaft (52a) via a spline, and a circular block around the motor shaft (52a) inside the cylinder block. The swash plate piston motor includes a plurality of reciprocating pistons housed in rows at positions, and adjusts a reciprocating process of these pistons by a swash plate (52b). When each piston receives the hydraulic oil supplied from the hydraulic pump (51) and presses the swash plate (52b), the cylinder block is rotated at a rotation speed corresponding to the supply flow rate of the hydraulic oil, and this rotation is performed by the motor. Output to the axis (52a).

A gear (56) connected to the motor shaft (52a) is meshed with a gear (41f) connected to a connecting shaft (41e) integral with the first sun gear (41a), whereby The output rotation from the motor shaft (52a) is transmitted to the first sun gear (41a).

The swash plate (52b) of the hydraulic motor (52)
The swash plate angle of the hydraulic motor (52) is set to be inclined by the hydraulic motor swash plate angle changing device (57) which operates in response to an operation signal from the controller (3). On the low speed side of the first to third modes and the fourth mode, the maximum inclination angle (17 °) is set, while on the high speed side of the fourth mode, the minimum swash plate angle (6 °) is set. The hydraulic motor swash plate angle changing device (57) is constituted by, for example, an actuator operated by pressure oil, and receives an operation signal from a controller (not shown) and receives an operating signal from a control auxiliary pump (not shown). And thereby the swash plate (52b) is moved to the maximum inclination angle (17).
(°) or the minimum inclination angle (6 °).

With the above configuration, in the HST (5), when the vehicle is accelerated, the hydraulic oil discharged from the hydraulic pump (51) is supplied to one of the communication pipes (53a or 53b).
Is supplied to the hydraulic motor (52), and after rotating the hydraulic motor (52), the other communication pipe (53)
b or 53a) and is returned to the hydraulic pump (51) to circulate in the closed circuit (53).

When the vehicle is decelerated, the hydraulic motor (52) is driven to rotate from the output shaft side by the inertia of the vehicle and operates the pump. Hydraulic oil discharged from is supplied to the hydraulic pump (51) through the other communication pipe (53b or 53a), and the hydraulic pump (51) is operated by a motor.

[Shift operation of MT and HST] MT
(4) and HST (5) are divided into four operation modes from the first to fourth modes according to the gear ratio of HMT (2) by operation control of a controller (not shown), that is, low from start. A first mode in a speed ratio range (low speed range);
A second mode in the middle / low speed ratio range (middle / low speed range), a third mode in the middle / high speed ratio range (middle / high speed range), and a high speed ratio range (high speed range)
It is configured to be operated in four operation modes of the fourth mode.

FIG. 7 shows how the gear ratio of the HMT (2) changes in the four operation modes of the first to fourth modes. FIG. 7 shows each clutch mechanism (44, 45, MT) of the MT (4) in the first to fourth operation modes.
..) Are shown.

When the vehicle is accelerated by inputting a certain rotation speed (for example, 1800 rpm) from the engine, the variable swash plate (51) of the hydraulic pump (51) is used.
The relationship between the swash plate angle and the gear ratio of the HMT (2) is shown, and the rotational speeds of the input shaft (21) and the output shaft (22) and the gear ratio of the HMT (2) in this case are shown. Is shown. In the figure, S1, S2 and R2 indicate the rotation speeds of the first sun gear (41a), the second sun gear (42a) and the second internal gear (42c), respectively.

(First Mode) In the first mode, MT
By setting only the first clutch mechanism (44) and the fourth clutch mechanism (24) of (4) to the connected state, the input rotation from the input shaft (21) is transmitted only to the HST (5) side. , And the output shaft (22) is rotated only by the transmission force from the HST (5).

That is, in the forward speed change range in the first mode, the swash plate (52b) of the hydraulic motor (52) of the HST (5) has the swash plate angle of 17 on the forward rotation side (the (+) side). °, while the variable swash plate (51b) of the hydraulic pump (51) is at a swash plate angle of 17 ° on the reverse rotation side ((−) side) from the neutral position of the swash plate angle of 0 °. The motor is gradually tilted in the (-) direction to the maximum tilt position. In response to the change of the swash plate angle, the output rotation speed of the hydraulic motor (52) is continuously changed, and the output shaft ( 22) The output rotational speed is steplessly increased toward the forward side.

The reason why the fourth clutch mechanism (24) is connected is that the intermediate shaft (43) to which the second clutch (45) is connected at the time of switching from the first mode to the second mode. ) And the rotation of the tubular member (48) are synchronized. Therefore, the fourth clutch mechanism (24)
In the first mode, no torque is transmitted.

(Second Mode) In the second mode, only the second clutch mechanism (45) and the fourth clutch mechanism (24) are connected, whereby the rotation input from the input shaft (21) is HST ( While the input rotation is transmitted as it is to 5), the rotation reduced by the third planetary gear mechanism (23) with respect to the intermediate shaft (43) is transmitted to the fourth clutch mechanism (2).
4) and the second clutch mechanism (45).

The output shaft (22) is connected to the second planetary gear mechanism (4
It is rotated by the combination of the transmission force from the intermediate shaft (43) interposed by 2) and the transmission force from the HST (5) interposed by the first planetary gear mechanism (41).

That is, in the speed change range in the second mode, the swash plate (5) of the hydraulic motor (52) of the HST (5) is used.
2b) is fixed at the maximum tilt position, while the variable swash plate (51b) of the hydraulic pump (51) is shifted from the maximum tilt position on the reverse rotation side [(-) side] to the forward rotation side [(+) side]. ] To the maximum tilt position in the (+) direction.

The output rotation speed of the hydraulic motor (52) is steplessly changed in accordance with the increase of the swash plate angle in the (+) direction, so that H through the first planetary gear mechanism (41) is interposed.
The rotation from ST (5) is steplessly increased and the output shaft (2
2) The output rotation speed is steplessly increased toward the forward side.

(Third Mode) In the third mode, only the third clutch mechanism (46) and the fourth clutch mechanism (24) are connected, whereby the rotation input from the input shaft (21) is HST ( While the input rotation is directly transmitted to (5), the rotation reduced by the third planetary gear mechanism (23) to the tubular member (47) is transmitted to the fourth clutch mechanism (2).
4) and the third clutch mechanism (46).

As in the first mode, the swash plate (52b) of the hydraulic motor (52) of the HST (5) is fixed at the maximum inclination position, while the variable swash plate (51b) of the hydraulic pump (51) is fixed. The swash plate angle is gradually reduced in the (-) direction, whereby the output rotation speed of the hydraulic motor (52) is steplessly changed.

From the HST (5), the first planetary gear mechanism (4
By combining the rotation transmitted through 1) and the rotation transmitted from the tubular member (47), the output rotation speed of the output shaft (22) is steplessly increased toward the forward side.

(Fourth Mode) In the fourth mode, only the third clutch mechanism (46) and the fifth clutch mechanism (25) are connected, whereby the rotation input from the input shaft (21) is HST ( The input rotation is transmitted as it is to 5), while the input rotation is transmitted as it is to the intermediate shaft (43) and transmitted to the second sun gear (42a).

The output shaft (21) is connected to the second planetary gear mechanism (4
The rotation is performed by the transmission force from the second carrier (42d) of 2) and the rigidity of the transmission force from the HST (5) via the first sun gear (41a) of the first planetary gear mechanism (41).

Here, the reason why the third clutch mechanism (46) is in the connected state is that the second clutch mechanism (45) is connected at the time of transition to the lock-up operation in the fourth mode highest speed range. This is because the rotation of (43) and the cylindrical member (48) are synchronized. Therefore, the third clutch mechanism (46) does not transmit torque in the fourth mode.

In the fourth mode, the following speed increasing means is used. This is because the swash plate (52b) of the hydraulic motor (52) of the HST (5) is fixed at the maximum tilt position in the shift range on the low gear ratio side in the fourth mode, while the hydraulic pump (51) The swash plate angle of the variable swash plate (51b) is gradually increased in the (+) direction to 0 °. Thus, the output rotation speed of the hydraulic motor (52) is controlled so as to be changed steplessly.

On the other hand, in the shift range on the high gear ratio side in the fourth mode, unlike the respective modes, the swash plate (52b) of the hydraulic motor (52) is operated by the operation of the hydraulic motor swash plate angle changing mechanism (57). Is switched to the minimum tilt position, and the swash plate angle is set to approximately 1/3 of the maximum tilt angle, while the swash plate angle of the variable swash plate (51b) of the hydraulic pump (51) is set to approximately 1 / of each mode. It is controlled so as to be gradually increased at a rate of 3 to reach the maximum inclination angle. Thus, the output rotation speed of the hydraulic motor 52 is continuously changed at the same ratio as in each mode. The output rotation speed of the output shaft (22) is steplessly increased toward the forward side in accordance with the change in the output rotation speed of the hydraulic motor (52).

Further, before and after the switching of the first to fourth operation modes, the first to fifth clutch mechanisms (44, 45, 4) are set.
6, 24, 25) clutch plates (44a, 45) of both clutch mechanisms engaged and disengaged during the switching operation.
a, 46a, 24a, 25c) and the pressure plates (44b, 45b, 46b, 24b, 25b) are tuned at the same rotational speed, and the rotation is transmitted at a continuous gear ratio before and after the switching. Thereby, HMT
The speed ratio of (2) is continuously and continuously changed in all the speed ranges of the first to fourth modes.

In the two clutch mechanisms to be engaged and disengaged, first, as shown in FIG. 8, the clutch mechanism (clutch 2) on the engaged side is engaged by a clutch-on command (the solid line in FIG. 8). Then, the clutch mechanism (clutch 1) on the side to be disengaged is disengaged by a clutch-off command (shown by a dashed line in the figure), so that power transmission is performed even when the operation mode is switched. Will be continued.

The forward speed change range in the first mode corresponds to the range of arrow M1 in the planetary velocity diagram of FIG.
The shift range of the second mode is in the range of arrow M2 in the same figure, the shift range of the third mode is in the range of arrow M3 in the same figure, and the shift range of the fourth mode is the range of arrow M4 in the same figure. Each corresponds.

On the other hand, the high speed ratio range (high speed range) of the fourth mode
When the braking is performed from, the angle of the swash plate shown in FIG. 7 is changed from the fourth mode side to the first mode side, that is, the control opposite to the driving is performed using the controller. in this case,
Changes in vehicle speed, variable swash plate (51b) of hydraulic pump (51)
The change of the swash plate angle (θp) and the change of the swash plate angle (θm) of the swash plate (52b) of the hydraulic motor (52) are as shown in FIG. The vehicle speed gradually decreases in accordance with a change in the swash plate angle (θp) of the variable swash plate (51b).

[0057]

However, in the above-described transmission control apparatus for a vehicle transmission, the rapid change in the vehicle speed during rapid deceleration of the vehicle cannot be accompanied by the increase or decrease in the swash plate angle, and the change in the gear ratio is not possible. However, there is a problem that the vehicle cannot follow the decrease in vehicle speed. In particular, in an HMT having four or more operation modes in order to improve the operation efficiency of the vehicle, there is a significant delay in following the speed ratio with a decrease in vehicle speed.

That is, as shown in FIG. 9, between the fourth mode in the high speed ratio range and the first mode in the low speed ratio range,
It is necessary to operate the variable swash plate (51b) of the hydraulic pump (51) reciprocally 1.75 times.

Since a certain amount of time is required for the reciprocating movement of the variable swash plate (51b), the speed ratio is changed in response to a decrease in the vehicle speed from the start of the rapid deceleration of the vehicle to the end of the rapid deceleration. Is gradually delayed, and the engine speed decreases. As a result, the effectiveness of the engine brake is deteriorated, and there is a possibility of occurrence of knocking and engine stall (stall).

Further, at the end of rapid deceleration of the vehicle, the engine speed is greatly reduced, so that the required torque required for re-acceleration of the vehicle cannot be sufficiently obtained. For this reason, the change of the gear ratio of the HMT catches up with the decrease of the vehicle speed,
Until the engine speed increases and the desired torque is obtained, the vehicle cannot be accelerated satisfactorily. That is, there is a problem that the acceleration response of the vehicle is deteriorated.

In order to solve the above-mentioned problem, the present inventors, as shown in FIG. 10, when the vehicle speed is rapidly reduced by the driver's brake operation, the shift range on the low gear ratio side in the fourth mode. Swash plate (5) of hydraulic pump (51)
By changing only the mode while keeping the swash plate angle (θp) of 1b) at 0 °, the HM at the end of rapid deceleration of the vehicle
A technology was developed to reduce the transmission ratio of T without delaying the decrease in vehicle speed.

At the point where the engine speed becomes a relatively high speed at which the effect of the engine brake is high, the inclination of the variable swash plate (51b) is started,
The required torque required for re-acceleration of the vehicle can be immediately output, and the vehicle can be immediately re-accelerated after sudden deceleration. Therefore, it is possible to prevent a decrease in the acceleration responsiveness at the time of re-acceleration after the sudden deceleration of the vehicle.

In the control of the HMT shown in FIG. 10, as shown in FIG. 11, the fifth clutch mechanism (25) (clutch 1 in FIG. A clutch 2 on command and a clutch 1 off command are simultaneously output to the four clutch mechanism (24) (the clutch 2 in the figure), and the clutch 1 and the clutch 2 are switched.

When the HMT braking control shown in FIG. 10 is performed, the vehicle speed changes, the swash plate angle (θp) of the variable swash plate (51b) of the hydraulic pump (51) changes, and the hydraulic motor (52) changes. FIG. 12 shows the change in the swash plate angle (θm) of the swash plate (52b) in the case where the horizontal axis indicates the passage of time. Compared with the change in the vehicle speed shown in FIG. 9, it can be seen that the vehicle speed shown in FIG. 12 is reduced more quickly and the mode is switched in response to the rapid deceleration of the vehicle.

However, even in the above-described control of the swash plate angle, a problem occurs in that the transmission torque is disconnected and the clutch slips when the mode is jumped, and the stable running performance of the vehicle is impaired.

Therefore, the present invention has been made in order to solve the problems, and does not increase the capacity of the auxiliary pump used in the HST, that is, the response to a sudden deceleration of the vehicle without adversely affecting the HMT efficiency. It is another object of the present invention to provide a shift control device for a vehicle transmission that can prevent troubles such as engine stall caused by a response delay and prevent a response delay at the time of re-acceleration.

[0067]

To achieve the above object, according to the first aspect of the present invention, an input shaft (21) is provided.
, An output shaft (22), and between the input shaft (21) and the output shaft (22), a plurality of speed change clutch mechanisms (44, 45, 46,...) And a plurality of planetary gear mechanisms ( 41, 42) and a mechanical transmission (4) provided between the input shaft (21) and the output shaft (22) in parallel with the mechanical transmission (4), and the input shaft ( A hydraulic pump (51) connected to the 21) side and a hydraulic motor (52) connected to the output shaft (22) side; the hydraulic pump (51) and the hydraulic motor (52); And a hydrostatic transmission (5) having at least one of which is configured to be variable in capacity by increasing or decreasing a swash plate angle, wherein the hydraulic pump (51) is a hydraulic pump swash plate angle adjusting device. Having (55) and above The hydraulic motor (52) has a hydraulic motor swash plate angle adjusting device (57), and in the high speed ratio range at the time of driving, the hydraulic motor (52) exceeds the rotation speed of the hydraulic pump (51). ), The swash plate (52) of the hydraulic motor (52) is larger than the maximum inclination angle of the swash plate (51b) of the hydraulic pump (51) so that the rotation speed is higher.
A shift control device including speed increasing means for controlling the hydraulic pump tilt angle adjusting device (55) and the hydraulic motor swash plate angle adjusting device (57) such that the tilt angle of b) becomes smaller. The sudden deceleration determining means (32) for judging the sudden deceleration state of the vehicle, and when the sudden deceleration state of the vehicle is judged by the sudden deceleration determining means (32), the hydraulic pump The inclination angle of the swash plate (51b) of (51) and the swash plate (52b) of the hydraulic motor (52) is smaller than the maximum inclination angle of the swash plate (51b) of the hydraulic pump (51), and The inclination angle of the swash plate (51b) of the hydraulic pump (51) is adjusted by the hydraulic motor (52).
Control of the hydraulic pump swash plate angle adjusting device (55) and the hydraulic motor swash plate angle adjusting device (57) so as to be controlled within a range smaller than the inclination angle of the swash plate (52b) during rapid deceleration. And an inclination angle control means (33).

According to this shift control device, when the vehicle suddenly decelerates, the inclination angles of the swash plate angle of the hydraulic pump (51) and the swash plate angle of the hydraulic motor (52) are reduced, and the hydraulic pressure is reduced. The stroke of the swash plate of the pump (51) can be reduced. This makes it possible to increase the response speed without changing the capacity of the control auxiliary pump used in the HMT. As a result, it is possible to improve the response to sudden deceleration without adversely affecting the HMT efficiency, and as described in the above-described problem,
It is possible to prevent a trouble such as engine stall caused by a response delay and a response delay at the time of re-acceleration. Furthermore, since rapid deceleration can be handled without causing torque disconnection or clutch slippage, it is possible to suppress running instability due to interrupted torque and to suppress impact at the time of clutch engagement.

Next, the second aspect of the present invention is directed to the first aspect.
In the invention described in (1), the vehicle further includes a brake operation amount detection means (13) for detecting a brake operation amount of the driver of the vehicle, and the sudden deceleration control means (33) includes the brake operation amount detection means (13). When the brake operation amount detected by the above is equal to or more than the set amount, the vehicle is determined to be in a rapid deceleration state.

According to this configuration, when the driver's brake operation amount detected by the brake operation amount detecting means (13) is equal to or greater than the set amount, it can be determined that a large braking force is acting on the vehicle. In that case, the sudden deceleration state of the vehicle is determined. Therefore, it is easy to determine the sudden deceleration state of the vehicle, and it is possible to efficiently implement the operation and effect described in claim 1 described above.

Next, the invention according to claim 3 is based on claim 1
In the invention described in (1), an engine speed detecting means (14) for detecting an engine speed is provided, and the rapid deceleration determining means (32) is provided with the engine speed detecting means (14).
When the engine speed detected by the above is less than or equal to the set speed, it is determined that the vehicle is suddenly decelerated.

According to this configuration, when the vehicle is actually decelerated rapidly and the change in the gear ratio cannot follow the decrease in the vehicle speed, the engine speed detected by the engine speed detecting means (14) is detected. Is deemed to decrease with a decrease in vehicle speed, and a rapid deceleration state of the vehicle is determined based on the decrease in the engine speed to a set speed or lower. According to this, the same operation and effect as the invention described in claim 2 can be obtained.

Next, the invention according to claim 4 is directed to claim 1
In the invention described in (1), when the rapid deceleration determining means (32) determines a rapid deceleration state of the vehicle, the inclination angle of the swash plate (51b) of the hydraulic pump (51) and the hydraulic motor ( The swash plate angle of the swash plate (52b) of 52) is configured to be 1/3 of the maximum inclination angle of the swash plate (51b) of the hydraulic pump (51).

According to this configuration, when the vehicle is suddenly decelerated, the stroke of the swash plate of the hydraulic pump (51) can be reduced to 1/3 of the normal stroke, so that the capacity of the control auxiliary pump used in the HST is changed. Without increasing the response speed, the response speed can be tripled, and the effect obtained by the first aspect can be obtained efficiently.

[0075]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shift control device for a vehicle transmission according to an embodiment of the present invention will be described below with reference to the drawings. The structure of the continuously variable transmission including the HMT according to the present embodiment has been described in the related art.
Since the structure is the same as that of the continuously variable transmission shown in FIG. 5, the description here is omitted, and the shift control device which is a feature of the present invention will be described in detail below.

According to the transmission control apparatus of the present embodiment, referring to FIGS. 1 and 5, the rotation of input shaft (21) from engine (1) is transmitted to HMT (2), and HM
The output shaft (2) set to a predetermined rotation speed by T (2)
The drive wheels (11, 11) are connected to 2).

A controller (3) for controlling the HMT (2) is provided. The controller (3) has an accelerator operation amount sensor (12) for detecting an accelerator operation amount by the driver and a controller (3) for controlling the HMT (2). A signal from a brake operation amount sensor (13) for detecting a brake operation amount is input. The controller (3) is based on input signals from an accelerator operation amount sensor (12), a brake operation amount sensor (13), an input speed sensor (14), and an output speed sensor (15).
It controls the operation of the engine (1) and the shift control of the HMT (2).

Specifically, the controller (3) includes a basic control unit (31), a rapid deceleration determining unit (32) as a rapid deceleration determining unit, and a signal obtained from the rapid deceleration determining unit (32). A swash plate angle controller (33) for controlling the inclination of the swash plate (51b) of the hydraulic pump (51) and the swash plate (52b) of the hydraulic motor (52) based on the rapid deceleration. ing.

When the vehicle is accelerating, the basic control unit (31) operates the engine (1) at a low speed at a predetermined rotation speed, and according to the accelerator operation amount of the driver detected by the accelerator operation amount sensor (12). By increasing or decreasing the speed ratio of the HMT (2), the vehicle is accelerated to a traveling speed corresponding to the driver's speed request.

When the deceleration of the vehicle is determined based on the accelerator operation amount or the brake operation amount of the driver detected by the accelerator operation amount sensor (12) or the brake operation amount sensor (13), the engine (1) In order to operate the exhaust brake device (not shown) attached to the HMT (2) according to the decrease in the running speed of the vehicle, the engine speed is maintained at a predetermined speed at which a high engine braking effect is obtained. The gear ratio is gradually changed.

The rapid deceleration determining unit (32) receives input signals from the brake operation amount sensor (13) and the input rotation speed sensor (14), and receives the brake depression amount by the driver and the rotation speed of the input shaft (21). That is, it is configured to determine the rapid deceleration of the vehicle based on the engine speed).
Specifically, when the brake operation amount detected by the brake operation amount sensor (13) is equal to or more than a set amount, the vehicle is determined to be in a sudden deceleration state or the input rotation speed for detecting the rotation speed of the engine (1). When the engine speed detected by the sensor (14) is equal to or lower than the set speed, rapid deceleration of the vehicle is determined.

Further, a swash plate angle control unit for rapid deceleration (33)
Input a predetermined signal to the hydraulic pump swash plate angle control unit (33a) and the hydraulic motor swash plate angle control unit (33b) based on the vehicle rapid deceleration determination signal from the rapid deceleration determination unit (32). It is possible to do.

When a rapid deceleration determination signal is output from the rapid deceleration determination unit (32) to the swash plate angle control unit (33), a predetermined signal is output to the hydraulic pump swash plate angle control unit (33a). The stroke of the swash plate angle of the variable swash plate (51b) of the hydraulic pump (51) is set to 1/3 of the normal stroke, and a predetermined signal is also output to the hydraulic motor swash plate angle control unit (33b). The swash plate angle of the hydraulic motor (52) is controlled to 1/3 of the normal swash plate angle in the same manner as the swash plate angle of the hydraulic pump (51).

When the rapid deceleration determining unit (32) determines that the vehicle is suddenly decelerated, as described above, the hydraulic pump swash plate angle control unit (33a) and the hydraulic motor swash plate angle control unit (33b) )), A predetermined signal is output, and M
A predetermined signal for performing control during rapid deceleration is also output to the clutch control unit (33c) for controlling the clutch mechanism of T (4).

Next, referring to FIG. 2, when the vehicle is suddenly decelerated, the change in the gear ratio, the change in the swash plate angle (θp) of the hydraulic pump (51), and The swash plate angle change (θm) of the hydraulic motor (52) will be described.

First, the swash plate angle (θ) of the hydraulic motor (52)
m), the swash plate angle is set to 17/3 ° from the fourth mode to the first mode. Accordingly, the stroke of the swash plate angle (θp) of the hydraulic pump (51) is 17/3 ° of the stroke of the swash plate angle of the hydraulic motor (52). It becomes 1/3.

Therefore, the response speed of the swash plate of the hydraulic pump (51) can be tripled. as a result,
The change in the gear ratio is, as compared to that shown in FIG.
It will change linearly, and while responding to sudden deceleration, there will be no intermittent torque, it will be possible to maintain a stable engine braking effect, and it will be possible to prevent shock and clutch wear. Become. Also, as shown in FIG. 3, it is possible to control the on / off of the clutch mechanism so that a clutch 2 on command is first output to the clutch 2 and then a clutch 1 off command of the clutch 1 is output. become.

The change in vehicle speed, the change in the swash plate angle (θp) of the variable swash plate (51b) of the hydraulic pump (51), and the change in the swash plate angle (θm) of the swash plate (52b) of the hydraulic motor (52). )
As shown in FIG. 4, when the horizontal axis indicates the passage of time, the swash plate angle of the hydraulic pump (51) can be changed in response to rapid deceleration of the vehicle.

As a result, it is possible to increase the response to sudden deceleration without increasing the capacity of the auxiliary pump used for the HST, and without adversely affecting the efficiency of the HMT, which has conventionally been a problem. It is possible to prevent troubles such as engine stall caused by a response delay, and to prevent a response delay at the time of re-acceleration. Furthermore, as shown in FIG. 2, since it is possible to cope with rapid deceleration without generating torque disconnection or clutch slippage,
It is possible to suppress running instability due to intermittent torque and to suppress impact at the time of clutch engagement.

In the above-described embodiment, the swash plate angle of the hydraulic pump (51) and the swash plate angle of the hydraulic motor (52) are controlled to be 1/3 of the normal angle. The value is not necessarily limited to this value, and other optimal values can be set. Further, the above-described continuously variable transmission has been described for the case of the continuously variable transmission of the four modes. However, the continuously variable transmission of the fifth embodiment or the multi-mode continuously variable transmission can be similarly implemented. Similar functions and effects can be obtained even when used in a continuously variable transmission provided with a look-up mechanism for improving transmission efficiency as much as possible.

Therefore, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0092]

According to the first aspect of the present invention, when the vehicle suddenly decelerates, the inclination angle of each of the swash plate angle of the hydraulic pump (51) and the swash plate angle of the hydraulic motor (52) is reduced. Thus, the stroke of the swash plate of the hydraulic pump (51) can be reduced. As a result, without changing the capacity of the auxiliary pump for control used in the HMT,
The response speed can be increased.

As a result, it is possible to improve the response to sudden deceleration without adversely affecting the HMT efficiency, and to prevent and prevent troubles such as engine stall caused by response delay as described in the above-mentioned problem. It is possible to prevent a response delay during acceleration. Furthermore, since rapid deceleration can be handled without causing torque disconnection or clutch slippage, it is possible to suppress running instability due to interrupted torque and to suppress impact at the time of clutch engagement.

Next, according to the second aspect of the present invention, in the first aspect of the present invention, the driver's brake operation amount detected by the brake operation amount detection means (13) is equal to or greater than a set amount. In some cases, it can be determined that a large braking force is acting on the vehicle, and in that case, a rapid deceleration state of the vehicle is determined. Therefore, it is easy to determine the sudden deceleration state of the vehicle, and it is possible to efficiently implement the operation and effect described in claim 1 described above.

Next, according to the third aspect of the present invention, in the first aspect of the present invention, when the vehicle is actually suddenly decelerated, and the change in the gear ratio cannot completely follow the decrease in the vehicle speed. Considers that the engine speed detected by the engine speed detecting means (14) decreases as the vehicle speed decreases, and the rapid deceleration state of the vehicle is determined based on the decrease of the engine speed below the set speed. You. According to this, the same operation and effect as the invention described in claim 2 can be obtained.

Next, according to a fourth aspect of the present invention, in the first aspect of the invention, when the vehicle is rapidly decelerated, the stroke of the swash plate of the hydraulic pump (51) is reduced to 1 / the normal stroke. Therefore, the response speed can be tripled without changing the capacity of the control auxiliary pump used in the HST, and the operation and effect obtained by the first aspect can be obtained efficiently.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram showing a configuration of an HMT according to the present embodiment.

FIG. 2 is a diagram illustrating a relationship between a gear ratio of an HMT, a swash plate angle of a hydraulic pump, and a swash plate angle of a hydraulic motor in the present embodiment.

FIG. 3 is an explanatory diagram showing a clutch switching operation at the time of sudden deceleration in the present embodiment.

FIG. 4 is a diagram showing a relationship between a change in vehicle speed, a change in a swash plate angle of a hydraulic pump, and a change in a swash plate angle of a hydraulic motor during rapid deceleration in the HMT according to the present embodiment.

FIG. 5 is an overall schematic diagram illustrating a configuration of an HMT.

FIG. 6 is a planetary speed diagram of the first and second planetary gear mechanisms in the MT of the HMT shown in FIG. 5;

FIG. 7 shows the connection state of each clutch mechanism in the HMT shown in FIG. 5, the swash plate angle and HM of the variable swash plate of the hydraulic pump.
FIG. 4 is an explanatory diagram showing the relationship between the speed ratio of T, the rotational speeds of the input shaft and the output shaft, and the relationship of the speed ratio of HMT in association with each other.

8 is an explanatory diagram showing a clutch switching operation during normal acceleration and deceleration of the HMT shown in FIG. 5;

9 is a diagram showing a relationship between a change in vehicle speed, a change in swash plate angle of a hydraulic pump, and a change in swash plate angle of a hydraulic motor when the HMT shown in FIG. 5 is decelerated.

10 shows the relationship between the change of the gear ratio, the change of the swash plate angle of the hydraulic pump, and the change of the swash plate angle of the hydraulic motor when the problem at the time of rapid deceleration of the HMT shown in FIG. 5 is solved. FIG.

11 is an explanatory diagram showing a clutch switching operation at the time of sudden deceleration in FIG.

FIG. 12 shows a change in vehicle speed during rapid deceleration shown in FIG.
It is a figure which shows the relationship between the change of the swash plate angle of a hydraulic pump, and the change of the swash plate angle of a hydraulic motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Engine 2 HMT (Continuously variable transmission) 3 Controller 4 MT (Mechanical transmission) 5 HST (Hydrostatic transmission) 11 Drive wheel 13 Brake operation amount sensor (Brake operation amount detection means) 14 Input rotation speed sensor (Engine rotation) 31) Basic control unit 32 Sudden deceleration determination unit 33 Swash plate angle control unit at the time of sudden deceleration 33a Hydraulic pump swash plate angle control unit 33b Hydraulic motor swash plate angle control unit 33c Clutch control units 44, 45, 46, 24, 25 Clutch mechanism (transmission clutch) 51 Hydraulic pump 52 Hydraulic motor

Claims (4)

[Claims] An input shaft (21), an output shaft (22), and a plurality of transmission clutch mechanisms (44, 45, 46) provided between the input shaft (21) and the output shaft (22). ,
..) And a plurality of planetary gear mechanisms (41, 42), and a mechanical transmission (4) between the input shaft (21) and the output shaft (22) with respect to the mechanical transmission (4). A hydraulic pump (51) provided in parallel and connected to the input shaft (21) side and a hydraulic motor (52) connected to the output shaft (22) side; ) And a hydrostatic transmission (5) in which at least one of the hydraulic motors (52) is configured to have a variable capacity by increasing or decreasing the swash plate angle. ) Has a hydraulic pump swash plate angle adjusting means (55), and the hydraulic motor (52) has a hydraulic motor swash plate angle adjusting means (57). , The hydraulic pump (51 The rotational speed of the hydraulic motor (52) is higher than the rotational speed of the hydraulic motor (52), so that the maximum inclination angle of the swash plate (51b) of the hydraulic pump (51) is smaller than the maximum inclination angle of the hydraulic motor (52). Swash plate (52b)
Shift control for a vehicle transmission, including speed increasing means for controlling the hydraulic pump tilt angle adjusting means (55) and the hydraulic motor swash plate angle adjusting means (57) so that the tilt angle of the hydraulic pump becomes smaller. A rapid deceleration determining means for determining a rapid deceleration state of a vehicle (32)
When the rapid deceleration determining means (32) determines the rapid deceleration state of the vehicle, the inclination angle of the swash plate (51b) of the hydraulic pump (51) and the fluid The inclination angle of the swash plate (52b) of the pressure motor (52) is
The inclination angle of the swash plate (51b) of the hydraulic pump (51) is smaller than the maximum inclination angle of the swash plate (51b) of the hydraulic pump (51), and the inclination angle of the hydraulic motor (52) is Rapid deceleration inclination angle for controlling the hydraulic pump swash plate angle adjustment means (55) and the hydraulic motor swash plate angle adjustment means (57) so as to be controlled within a range smaller than the inclination angle of the plate (52b). And a control unit (33). 2. A brake operation amount detection means (13) for detecting a brake operation amount of a driver of the vehicle, wherein the rapid deceleration control means (33) is controlled by the brake operation amount detection means (13). The shift control device for a vehicle transmission according to claim 1, wherein the shift control device for a vehicle transmission is configured to determine a sudden deceleration state of the vehicle when the detected brake operation amount is equal to or greater than a set amount. 3. An engine speed detecting means (14) for detecting a speed of the engine (1), wherein said rapid deceleration determining means (32) detects the engine speed detected by said engine speed detecting means (14). The shift control device for a vehicular transmission according to claim 1, wherein the shift control device is configured to determine a sudden deceleration of the vehicle when the rotation speed is equal to or less than a set rotation speed. 4. When the rapid deceleration determining means (32) determines a rapid deceleration state of the vehicle, the hydraulic pump (5)
The inclination angle of the swash plate (51b) and the swash plate angle of the swash plate (52b) of the hydraulic motor (52) are the maximum inclination angle of the swash plate (51b) of the hydraulic pump (51). 1 /
The shift control device for a vehicle transmission according to claim 1, wherein the shift control device is configured to be 3.