JPH0548396B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission in which gears are changed according to a preset shift pattern depending on vehicle driving conditions. 2. Description of the Related Art In general, an automatic transmission is configured to change gears according to a preset shift pattern based on various shift signals indicating vehicle operating conditions. A throttle opening signal and a vehicle speed signal are normally used as shift signals indicating the vehicle operating state, but there are also systems in which a temperature signal is used as an element of shift control. For example, the 1982 version of the maintenance manual "Automatic Transmission" L4N71B published by Nissan Motor Co., Ltd.
Model E4N71B (published in November 1982), page 21, is equipped with an oil temperature sensor, and the oil temperature of the hydraulic control device detected by the oil temperature sensor is below 15℃, which means that engine operation becomes unstable. An automatic transmission is shown that prohibits shifting to overdrive (fourth gear), which is a high speed gear, when the engine is cold. Problems to be Solved by the Invention However, with such conventional transmission control devices, after starting the engine in cold weather, until the oil temperature rises to 15°C, no matter how high the speed is driven, the system will not shift to overdrive. Shifting is not performed. Therefore, in this state, 3rd gear is the highest gear, so the engine speed increases significantly when driving at high speeds, causing noise and discomfort in driving performance compared to overdrive driving, as well as deteriorating fuel efficiency. There is a problem that occurs. On the other hand, the shift map that stores the shift pattern,
It has also been considered to set a plurality of characteristics corresponding to different temperature conditions, and to switch the shift map according to the detected temperature, thereby causing the shift to be performed at a shift point corresponding to the actual temperature. However, in such a configuration, in order to accommodate a wide range of temperatures, it is necessary to prepare a large number of speed change maps, and there are problems such as requiring a large memory capacity. In addition, if the displacement of the engine combined with the automatic transmission differs, the effects of temperature will be different, so it is necessary to set a gear shift map corresponding to each, making it difficult to adapt to many car models. It is. Means for Solving the Problems Therefore, in the present invention, by correcting the vehicle speed signal, which is the basis of shift control, based on temperature, the shift point can be substantially shifted without changing the memorized shift pattern itself, and the temperature It is now possible to obtain the optimum shift point according to the situation. That is, the shift control device for an automatic transmission according to the present invention, as shown in FIG.
In automatic transmission a, a gear position is determined according to a preset shift pattern using a gear change signal including at least a vehicle speed signal, and a gear change is performed in accordance with this gear position. A correction signal outputted from the correction means c, comprising a temperature detection means b for detecting the temperature, and a correction means c for correcting the vehicle speed signal based on the signal from the temperature detection means b and outputting the correction signal. The present invention is characterized in that the gear stage is determined from the shift pattern based on the shift pattern. Effect With the above-described configuration, in the speed change control device of the present invention, the vehicle speed signal that determines the gear position is temperature-corrected by the correction means c, and the speed is changed according to a predetermined speed change pattern based on the corrected vehicle speed signal. The stage is determined. Therefore, even with one type of speed change pattern, the actual speed change points take various forms depending on the temperature, and speed change control that takes temperature conditions into consideration is realized. Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. That is, FIG. 2 shows the entire circuit of a hydraulic pressure control device operated by the transmission control device of the present invention, and examples of power transmission in an automatic transmission controlled by this hydraulic pressure control device include, for example. There is one as shown in the schematic diagram of FIG. That is, this power transmission example is
A torque converter 3 that transmits rotation from the engine output shaft 1 to the input shaft 2, a first planetary gear set 4, a second
It is composed of a Yusei gear set 5, an output shaft 6, and various friction elements described below. The torque converter 3 is driven by the engine output shaft 1 and includes a pump impeller 3P that is also used to drive the oil pump O/P, and a turbine that is fluidly driven by the pump impeller via internal working fluid and transmits power to the input shaft 2. placed on a fixed shaft via a runner 3T and a one-way clutch 7,
It consists of a stator 3s that increases the torque to the turbine runner 3T, and a lock-up clutch 3 is attached to this stator 3s.
This is a normal lock-up torque converter with L added. The torque converter 3 receives working fluid from the release 3R, and while the working fluid is removed from the apply chamber 3A, the lock-up clutch 3L is released and engine power is pumped through the impeller 3P and turbine runner 3T (converter While increasing torque is transmitted to the input shaft 2 (in this state), working fluid is supplied from the apply chamber 3A, and working fluid is removed from the release chamber 3R, the lock-up clutch 3L is engaged and the engine power is increased. It is assumed that the signal is transmitted as is to the input shaft 2 via the lock-up clutch (in the lock-up state). In the latter lock-up state, the slip of the lock-up torque converter 3 (pump impeller 3R and turbine runner 3
The relative rotation of T can be arbitrarily controlled (slip control). The first planetary gear set 4 is a normal simple planetary gear set consisting of a sun gear 4S, a ring gear 4R, a pinion 4P that meshes with these gears, and a carrier 4C that rotatably supports the pinion 4P.
Sun gear 5S, ring gear 5R, pinion 5P
and carrier 5C. Next, the various friction elements mentioned above will be explained. The carrier 4C can be appropriately connected to the input shaft 2 via a high clutch H/C, and the sun gear 4S can be appropriately fixed by a band brake B/B, and can also be appropriately connected to the input shaft 2 by a reverse clutch R/C. . The Carrier 4C can be fixed appropriately using a multi-plate low-reverse brake brake LR/B, and
Reverse rotation (rotation in the opposite direction to the engine) is prevented via the row one-way clutch LO/C. Ring gear 4R is integrally connected to carrier 5C and output shaft 6
The sun gear 5S is coupled to the input shaft 2. Ring gear 5R is an overrun clutch
In addition to being able to connect to carrier 4C as appropriate via OR/C, forward one-way clutch FO/C
and is correlated to the carrier 4C via the forward clutch F/C. The forward one-way clutch FO/C connects the ring gear 5R to the carrier 4C in the reverse direction (the direction opposite to the engine rotation) when the forward clutch F/C is engaged. High clutch H/C, reverse clutch R/
C, low reverse brake LR/B, overrun clutch OR/C and forward clutch F/
C is operated by hydraulic pressure supply to perform the above-mentioned appropriate coupling and fixing, and band brake B/B is connected to 2-speed servo apply chamber 2S/A,
When the 3rd speed servo release chamber 3S/R and the 4th speed servo apply chamber 4S/A are set and the 2nd speed selection pressure P ₂ is supplied to the 2nd speed servo apply chamber 2S/A, the band brake B/B is activated. In this state, when the 3rd speed selection pressure _P3 is also supplied to the 3rd speed servo release chamber 3S/R, the band brake B/B becomes inactive, and then the 4th speed servo apply chamber 4S/A is also supplied with the 3rd speed selection pressure P3.
When the speed selection pressure _P4 is supplied, the band brake B/B is activated. Such a power transmission train includes friction elements B/B, H/
By operating C, F/C, OR/C, LR/B, and R/C in various combinations as shown in the table below,
Together with the appropriate differential of the friction elements FO/C and LO/C, the rotational state of the elements constituting the planetary gear sets 4 and 5 is changed, thereby changing the rotational speed of the output side 6 relative to the rotational speed of the input shaft 2. As shown in the table below, it is possible to obtain four forward speeds and one reverse speed. In addition, the ○ mark in the following table is activated (hydraulic inflow)
, where the cross symbol indicates the friction element that should be activated when engine braking is required. Then, while the overrun clutch OR/C is operated, the forward one-way clutch FO/C placed in parallel with it is inactive, and while the low reverse brake LR/B is operated, the forward one-way clutch FO/C is placed in parallel with it, as shown by the mark. Of course, the row one-way clutch LO/C becomes inoperative.

[Table] By the way, the hydraulic side control device shown in FIG. 2 includes a pressure regulator valve 20, a pressure modifier valve 22, a duty solenoid 24 as a solenoid valve, and a pilot valve 2.
6, torque converter regulator valve 28, lockup control valve 30, shuttle valve 32,
Duty solenoid 34, manual valve 36,
first shift valve 38, second shift valve 40, first shift solenoid 42, second shift solenoid 44,
Forward clutch control valve 46, 3-2
Timing valve 48, 4-2 Relay valve 50, 4-2
Sequence valve 52, I range pressure reducing valve 54, shuttle valve 56, overrun clutch control valve 58, third shift solenoid 60, overrun clutch pressure reducing valve 63, 2nd speed servo apply pressure accumulator 64, 3rd speed servo release pressure accumulator 66, 4-speed servo apply pressure accumulator 6 constituting the main part of the shock reduction device of the present invention
8, and an accumulator control valve 70, which are the main components of the torque converter 3, forward clutch F/C, high clutch H/C, band brake B/B, reverse clutch R/C, and low reverse brake. Connect to LR/B, overrun clutch OR/C, and oil pump O/P as shown. The pressure regulator valve 20 has a spool 20b elastically supported at the left half position in the figure by a spring 20a.
and the plug 2 that abuts against the lower end surface of the spool in the figure.
Basically, the oil pump O/P regulates the oil discharged to the circuit 71 to a certain pressure determined by the spring force of the spring 20a, but the plug 20c applies an upward force to the spool 20b in the figure. When the line pressure is increased, the above pressure is increased accordingly to reach a predetermined line pressure. For this purpose, the pressure regulator valve 20 is configured to receive the pressure in the circuit 71 via the damping orifice 72 to the pressure receiving surface 20d of the spool 20b, thereby biasing the spool 20b downward. Ports 20e to 20h open and close depending on the stroke position of 20b
will be established. Port 20e is connected to circuit 71, and is arranged so that as spool 20b descends from the left half position in the figure, it communicates with ports 20h and 20f.
The port 20f is arranged so that as the spool 20b descends from the left half position in the figure, communication with the port 20g serving as a drain port is reduced, and at the point when communication with this port is cut off, communication with the port 20e begins. And bleed 7 in the middle of port 20f.
Oil pump O/P via circuit 74 where 3 exists.
is connected to the capacity control actuator 75 of. The oil pump O/P is a variable capacity vane pump driven by the engine as described above, and the eccentricity is reduced when the pressure toward the actuator 75 exceeds a certain value, so that the capacity becomes smaller. The plug 20c of the pressure regulator valve 20 receives the modifier pressure from the circuit 76 on its lower end face in the figure, and receives the retreat selection pressure from the circuit 77 on the pressure receiving surface 20i, and the plug 20c receives the modifier pressure from the circuit 77 on its pressure receiving surface 20i, and the plug 20c receives the modifier pressure from the circuit 77 on its lower end face in the figure. Assume that a force of 2 is applied to the spool 20b. The pressure regulator valve 20 is normally in the left half state in the figure, and when oil is discharged from the oil pump O/P, this oil flows into the circuit 71. Circuit 7 at the left half position of spool 20b
The oil in No. 1 is not drained at all, and the pressure increases.
This pressure acts on the pressure receiving surface 20d through the orifice 72, pushes down the spool 20b against the spring 20a, and connects the port 20e to the port 20h. As a result, the above pressure is partially drained from the port 20h and lowered, and the spool 20b is pushed back by the spring 20a. By repeating this action, the pressure regulator valve 20 basically operates in the circuit 71.
The pressure inside (hereinafter referred to as line pressure) is set to a value corresponding to the spring force of the spring 20a. By the way, plug 2
An upward force from the modifier pressure from the circuit 76 acts on 0c, causing the plug 20c to come into contact with the spool 20b as shown in the right half of the figure, and this upward force is applied to the spool 20b to assist the spring 20a, and As will be described later, the modifier pressure is generated when the vehicle is not in reverse mode and increases in proportion to the engine load (engine output torque), so the above-mentioned line pressure increases as the engine load increases other than when the reverse mode is selected. When reversing is selected, an upward force is applied to the plug 20c by the retracting selection pressure (same value as the line pressure) from the circuit 77 instead of the modifier pressure described above, and this is applied to the spool 20b, so that the line pressure is kept at a desired constant value when reversing is selected. becomes. When the oil pump O/P reaches a certain rotational speed or higher (the engine rotates at a certain rotational speed or higher), the oil discharge amount that increases accordingly becomes excessive, and the pressure within the circuit 71 exceeds the pressure regulation value. This pressure lowers the spool 20b further from the pressure regulating position in the right half of the figure, communicates the port 20f with the port 20e, and blocks it from the drain port 20g. As a result, some of the oil in port 20e is removed from port 20f and bleed 73, but feedback pressure is generated within circuit 74. This feedback pressure increases as the rotational speed of the oil pump O/P increases, and reduces the eccentricity (capacity) of the oil pump O/P via the actuator 75. In this way, the capacity of the oil pump O/P is controlled so that the discharge amount remains constant while the rotational speed is above a certain value, thereby preventing an increase in power loss of the engine due to discharge of more oil than necessary. As mentioned above, the line pressure generated in the circuit 71 is transferred to the pilot valve 26, the manual valve 36, and the accumulator control valve 70 by the line pressure circuit 78.
and a third-speed servo release pressure accumulator 66. The pilot valve 26 includes a spool 26b elastically supported in the upper half position in the figure by a spring 26a, and the end face of the spool 26b far from the spring 26a is connected to a chamber 26c.
The pilot valve 26 is further provided with a drain port 26d, and a pilot pressure circuit 79 having a strainer S/T is maintained. and,
A communication hole 26e is provided in the spool 26b to guide the pressure of the pilot pressure circuit 79 to the chamber 26c, and the circuit 79 is switched and connected from the circuit 78 to the drain port 26d as it moves to the right in the figure. The pilot valve 26 is normally in the upper half of the figure, and when it is supplied with line pressure from the circuit 78, it increases the pressure in the circuit 79. The pressure in the circuit 79 reaches the chamber 26c through the communication hole 26e, causing the spool 26b to move to the right in the figure, and when the spool 26b exceeds the pressure regulating position shown in the lower half, the circuit 79 is cut off from the circuit 78, and at the same time, the drain port 26
Leads to d. At this time, the pressure in circuit 79 is reduced,
This pressure drop causes the spool 26b to spring 26a.
When pushed back, the pressure in the circuit 79 rises again. Thus, the pilot valve 26 can reduce the line pressure from the circuit 78 to a constant value determined by the spring force of the spring 26a, and output it to the circuit 79 as pilot pressure. This pilot pressure is applied to the pressure modifier valve 22 and the duty solenoid 2 through a circuit 79.
4, 34, lockup control valve 30, forward clutch control valve 46, shuttle valve 32, first, second, third shift solenoid 4
2, 44, 60, and the shuttle valve 56. The duty solenoid 24 consists of a coil 24a, a spring 24d, and a plunger 24b.
The circuit 81 connected to the pilot pressure circuit 79 via the orifice 80 is turned on (energized) by the coil 24a.
It is assumed that the drain port 24c communicates with the drain port 24c.
This duty solenoid 24 turns on the coil 24a at regular intervals by a computer (not shown).
The circuit 81 is turned OFF, and the ratio of ON time to the constant period (duty ratio) is controlled.
A control pressure is generated in accordance with the duty ratio.
The duty ratio is made smaller as the engine load (for example, engine throttle opening) increases except when the reverse is selected, so that the above-mentioned control pressure is made higher as the engine load increases. Further, when selecting reverse, the duty ratio is set to 100%, and the above control pressure is set to 0. The pressure modifier valve 22 has a spring 22a.
The pressure modifier valve 22 further includes an output port 22c to which the circuit 76 is connected, and an input port to which the pilot pressure circuit 79 is connected. Port 22d and drain port 2
2e is provided, and the spool 22b is far from the spring 22a.
A circuit 76 is connected to the chamber 22f facing the end face. These ports are arranged so that the port 22c is exactly blocked from the ports 22d and 22e at the left half of the spool 22b in the figure. The pressure modifier valve 22 has a spring 22
The spool 22b receives the spring force from a and the force from the control pressure from the circuit 81 downward in the figure, and the spool 22b receives the force due to the output pressure from the port 22c that has reached the chamber 22f upward in the figure. The spool 22b is stroked to a balanced position. If the output pressure from the port 22c is insufficient to match the downward force, the spool 22b descends beyond the pressure regulating position shown in the left half. At this time, the port 22c communicates with the port 22d, and receives supplementary pilot pressure from the circuit 79 to increase the output pressure. Conversely, if this output pressure is too high to match the above-mentioned downward force, spool 2
2b rises toward the right half position in the figure. At this time, the port 22c communicates with the drain port 22e, and the output pressure is reduced. By repeating this action, the pressure modifier valve 22 regulates the output pressure from the port 22c to a value corresponding to the sum of the spring force of the spring 22a and the force due to the control pressure from the circuit 81.
This is supplied to the plug 20c of the pressure regulator valve 20 from the circuit 76 as a modifier pressure. By the way, as mentioned above, the control pressure increases as the engine load increases except when reverse is selected, and is 0 when reverse is selected, so the modifier pressure is also a value obtained by amplifying this control pressure by the spring force of the spring 22a. It increases as the engine load increases except when the reverse is selected, and becomes 0 when the reverse is selected, allowing the pressure regulator valve 20 to control the line pressure described above. Torque converter regulator valve 28 has spring 2
8a, the spool 28b is elastically supported in the right half position in the figure, and the port 28
c to the port 28d, and as the spool 28b rises from the left half position in the figure, the port 28c
The degree of communication is decreased for port 28d, port 2
It is assumed that the degree of connectivity is increased relative to 8e. In order to control the stroke of the spool 28b, a chamber 28f facing the spool end face far from the spring 28a is communicated with the port 28c through a communication hole 28g provided in the spool 28b. The port 28c is connected to a predetermined lubricating part via a relief valve 82 and connected to the lockup control valve 30 via a circuit 83, and the port 28d is connected to the port 20 of the pressure regulator valve 20 via a circuit 84.
h, and port 28e is connected by circuit 85 to lockup control valve 30. circuit 8
5 has an orifice 86 in the middle, and the orifice and port 28c are connected to a circuit 83 via an orifice 87, and are communicated to an oil cooler 89 and a predetermined lubricating section 90 by a circuit 88. The torque converter regulator valve 28 is normally in the right half state in the figure, where oil flows from the port 20h of the pressure regulator valve 20 to the circuit 8.
4, this oil is directed from circuit 83 to torque converter 3 as described below. When supply pressure to the torque converter is generated, this torque converter supply pressure is applied to the communication hole 2.
8g, the chamber 28f is reached, and the spool 28b is raised against the spring 28a in the figure. When the spool 28b rises from the left half position in the figure due to an increase in the torque converter supply pressure, the port 28e opens and a portion of the torque converter supply pressure is removed through the port 28e and the circuit 88, thereby reducing the torque converter supply pressure. The pressure is adjusted to a value determined by the spring force of the spring 28a. The oil removed from the circuit 88 is cooled by an oil cooler 89 and then directed to a lubricating section 90. In addition, the torque converter regulator valve 28
If the torque converter supply pressure exceeds the above value even with the above-mentioned pressure regulating action, the relief valve 82 opens and the excess pressure is released to the corresponding lubricating part, thereby preventing deformation of the torque converter 3. The lock-up control valve 30 is connected to the spool 3
0a and the plug 30b coaxially butted,
When the spool 30a is at the limit position shown in the right half, the circuit 83 is connected to the circuit 91 from the torque converter release chamber 3R, and when the spool 30a is lowered to the left half position in the figure, the circuit 83 is connected to the circuit 85. When the spool 30a further descends, the circuit 91 is connected to the drain port 30c. In order to control the stroke of the spool 30a, the end face of the spool 30a far from the plug 30a faces the chamber 30d, and the orifice 9 is placed in the chamber 30e facing the end face of the plug 30b far from the spool 30a.
2 to lead the pressure of the circuit 91. Note that the circuit 93 from the torque converter apply chamber 3A is connected to the circuit 85 at a location closer to the lockup control valve 30 than the orifice 86. Further, the pilot pressure from the circuit 79 is applied to the plug 30b through the orifice 94 to continue applying a downward force in the figure, thereby preventing pulsation of the spool 30a. The lock-up control valve 30 stroke-controls the spool 30a by the pressure supplied to the chamber 30d, and while this pressure is sufficiently high, the spool 30a
maintains the right half position in the figure. At this time, the oil from the circuit 83 flows through the circuit 91, the release chamber 3R, the apply chamber 3A, the circuit 93, and the circuit 85 under pressure regulation by the torque converter regulator valve 28.
Excluded from 8. Thus, the torque converter 3 transmits power in the converter state. As the pressure within chamber 30d decreases, spool 30a is forced to close plug 30 by pressure from orifices 92, 94.
b, and further descends from the left half position in the figure, the pressure regulating oil from circuit 83 flows to circuits 85, 93, apply chamber 3A, release chamber 3R, circuit 91, and drain port 30c. The torque converter 3 transmits power in a slip control state in which the slip decreases as the pressure in the chamber 30d decreases. If the pressure inside the chamber 30d is further reduced from this state, the spool 3
Due to the different lowering of 0a, the circuit 91 is completely communicated with the drain port 30c, the pressure in the release chamber 3R is reduced to 0, and the torque converter 3 transmits power in a locked-up state. The shuttle valve 32 controls the stroke of the lockup control valve 30 together with a forward clutch control valve 46, which will be described later.
A spool 32b is elastically supported by 2a in the lower half position in the figure, and this spool is appropriately switched to the upper half position in the figure by the pressure inside the chamber 32c. The shuttle valve 32 connects the circuit 95 of the chamber 30d to the pilot pressure circuit 7 when the spool 32b is in the lower half position in the figure.
9 and extending from chamber 46a of forward clutch control valve 46.
is connected to a circuit 97 from the duty solenoid 34, and when the spool 32b is in the upper half position in the figure, the circuit 95 is connected to the circuit 97, and the circuit 96 is connected to the circuit 79. The duty solenoid 34 is a plunger 34 elastically supported in a closed position by a coil 34a and a spring 34d.
A circuit 97 connected to the pilot pressure circuit 79 via an orifice 98 is connected to the coil 34a.
When it is ON (energized), it is connected to the drain port 34c. This duty solenoid 34 is controlled by a computer (not shown) to turn the coil 34a ON and OFF at a constant cycle, and also controls the ratio of the ON time to the constant cycle (duty ratio), so that the coil 34a is controlled in accordance with the duty ratio in a circuit 97. generates control pressure. When the control pressure of the circuit 97 is used to control the stroke of the lock-up control valve 30 with the shuttle valve 32 in the upper half state in the figure, the duty ratio of the solenoid 34 is determined as follows. In other words, under high load and low rotation speeds of the engine where the torque increasing function and torque fluctuation absorbing function of the torque converter 3 are absolutely necessary, the duty ratio is set to 0.
%, thereby making the control pressure of circuit 97 the same as the pilot pressure of circuit 79, which is the source pressure. At this time, the control pressure maintains the spool 30a in the right half position in the figure in the chamber 30d, and maintains the torque converter 3 in the converter state to meet the above requirements. As the requirements for both of the above functions of the torque converter 3 become lower, the duty ratio is increased and the control pressure is lowered.
The torque converter 3 is operated in a slip control state that matches the demand through The torque converter 3 is maintained in the locked-up state as required via the lock-up control valve 30 by setting the pressure to zero. Note that when the shuttle valve 32 is in the lower half state in the figure and the control pressure of the circuit 97 is used to control the stroke of the forward clutch control valve 46, the duty ratio of the solenoid 34 reduces the N→D selection shock as described later. determined to prevent creep. The manual valve 36 is operated by the driver to select parking (P) range, reverse (R) range, neutral (N) range, forward automatic shift (D) range, forward second gear engine brake () range, and first forward gear range. Spool 3 stroked to high speed engine brake () range
6a, and the line circuit 78 is connected to ports 36D and 36 according to the selected range of the spool as shown in the following table.
, 36, 36R. Note that in this table, ○ marks indicate ports that communicate with the line pressure circuit 78, and no marks indicate ports that are drained.

[Table] The first shift valve 38 includes a spool 38b elastically supported in the left half position in the figure by a spring 38a, and this spool is switched to the right half position in the figure when pressure is supplied to the chamber 38c. . When the spool 38b is in the left half position, the first shift valve 38 changes the port 38d to the drain port 38e and the port 38f to the drain port 38e.
to port 38g, port 38h to port 38i
When the spool 38b is in the right half position in the figure, the port 38d is connected to the port 38j, and the port 3 is connected to the port 38j.
8f to port 38k, port 38h to port 3
8l each. The second shift valve 40 includes a spool 40b elastically supported in the right half position in the drawing by a spring 40a, and this spool assumes the right half position in the drawing when pressure is supplied to the chamber 40c. and second shift valve 40
When the spool 40b is in the left half position in the figure, the port 40d is connected to the drain port 40e, the port 40f is connected to the port 40g, and the port 40h is connected to the drain port 40i with an orifice, and the spool 40
When b is in the right half position in the figure, port 40d is connected to port 4.
0j, port 40f to drain port 40e,
It is assumed that each port 40h is connected to a port 40k. The spool positions of the first and second shift valves 38 and 40 are controlled by a first shift solenoid 42 and a second shift solenoid 44, respectively, and these shift solenoids are connected to coils 42a and 44a, respectively.
and plungers 42b, 44b, spring 42
d, 44d. 1st shift solenoid 4
2 is connected to the pilot pressure circuit 79 via the orifice 99, and connects the circuit 100 to the chamber 38c.
Drain port 42 when coil 42a is ON (energized)
c, the control pressure in the circuit 100 is set to the same value as the pilot pressure which is the source pressure, and the first shift valve 38 is thereby switched to the right half state in the figure. Further, the second shift solenoid 44 is connected to the pilot pressure circuit 79 via the orifice 101, and the circuit 102 leading to the chamber 40c is connected to the coil 44a.
When turned on (energized), the drain port 44c is shut off to make the control pressure in the circuit 102 the same value as the original pilot pressure, thereby switching the second shift valve 40 to the right half state in the figure. Turn on these shift solenoids 42 and 44,
The first to fourth forward speeds can be obtained by combinations of the OFF states and, therefore, the states of the shift valves 38 and 40, which are summarized in the table below.

[Table] In this table, the ○ mark indicates the right half of the shift valve in the figure (ascended), and the × mark indicates the left half of the shift valve in the figure (down) state, and the shift solenoid 42,
A computer (not shown) determines a suitable gear position based on the vehicle speed and engine load based on a predetermined gear shift pattern, and determines whether to turn on or off 44 in accordance with this gear position. The forward clutch control valve 46 includes a spool 46b on which the pilot pressure from the circuit 79 guided through the orifice 103 is applied downward in the figure to prevent pulsation of the spool, and further includes a orifice 10
4, the operating pressure of the forward clutch F/C in the circuit 105 is fed back and applied downward in the figure. The spool 46b is stroked to a position where the downward force in the figure due to these pressures and the force due to the pressure inside the chamber 46a are balanced.
When the spool 46b is in the right half position in the figure, the circuit 105
is connected to the drain port 46c, and when in the left half position in the figure, the circuit 105 is connected to the circuit 106, and the circuit 105 has a one-way orifice 107 that exerts a throttling effect only on the hydraulic pressure directed to the forward clutch F/C. The circuit 106 is connected to the port 36D of the manual valve 36. 3-2 The timing valve 48 includes a spool 48b elastically supported at the left half position in the figure by a spring 48a. At this spool position, a port 48c and a port 48d with an orifice 48f communicate with each other, and the chamber 48
It is assumed that when the pressure in e is high and the spool 48b is at the right half position in the figure, the ports 48c and 48d are shut off. 4-2 The relay valve 50 includes a spool 50b elastically supported at the left half position in the figure by a spring 50a, and at this spool position, the port 50c is connected to the drain port 50d with an orifice, and pressure is supplied into the chamber 50e. It is assumed that when the spool 50b is at the right half position in the figure, the port 50c communicates with the port 50f. 4-2 The sequence valve 52 includes a spool 52b elastically supported in the right half position in the figure by a spring 52a, and in this spool position, the port 52c is connected to the drain port 52d with an orifice, and the pressure inside the chamber 52e is high and the spool is closed. It is assumed that when 52b is in the left half position in the figure, port 52c communicates with port 52f. The range pressure reducing valve 54 includes a spool 54b biased toward the right half position in the figure by a spring 54a, and a port 54c, which communicates with each other at this spool position.
54d, and a drain port 54e that begins to communicate with the port 54c when the spool 54b rises to the left half position in the figure and finishes closing the port 54d. A chamber 54f facing the end face of the spool 54b far from the spring 54a is connected to the port 54c via an orifice 108. Thus, the range pressure reducing valve 5
4 is normally in the right half state in the figure, and when pressure is supplied to the port 54d, pressure is output from the port 54c. This output pressure is the orifice 108
The pressure is applied to the lower end surface of the spool 54b in the figure, and as the output pressure increases, the spool 54b is raised in the figure. When the spool 54b rises above the left half position in the figure, the port 54c communicates with the drain port 54e and reduces the output pressure from the port 54c.
When the spool 54b is lowered to more than the left half position in the figure due to this output pressure drop, the port 54c is
4d and increases the output pressure from port 54c. By repeating this action, the output pressure from the port 54c is reduced to a constant value determined by the spring force of the spring 54a. The shuttle valve 56 includes a spool 56b elastically supported in the left half position in the figure by a spring 56a, and this spool is held in this position when there is a pressure supply to the chamber 56g; When the upward force in the figure due to the pressure from the port 56c exceeds a certain value, it is stroked to the right half position in the figure. Port 56d is connected to the circuit 109 from the third shift solenoid 60 at the left half position in the figure, port 56e is connected to the drain port 56f, and port 56d is connected to the pilot pressure circuit 79 at the right half position in the figure. is connected to the circuit 109. The third shift solenoid 60 includes a coil 60a, a plunger 60b, and a spring 60d.
Pilot pressure circuit 79 via orifice 110
Turn on the circuit 109 connected to the coil 60a.
(When energized), the drain port 60c is cut off, and the control pressure in the circuit 109 is set to the same value as the pilot pressure, which is the source pressure. Note that whether the third shift solenoid 60 is turned on or off is determined by a computer (not shown). It is assumed that the overrun clutch control valve 58 includes a spool 58b elastically supported in the left half position in the figure by a spring 58a, and this spool is switched to the right half position in the figure when pressure is supplied to the chamber 58c. In addition, the spool 58b is located at the left half position in the figure, and the port 58d is connected to the drain port 58e, and the port 58f is connected to the drain port 58e.
are connected to the port 58g, and at the right half position in the figure, the port 58d is connected to the port 58h, and the port 58f is connected to the drain port 58e. The overrun clutch pressure reducing valve 62 has a spring 62a.
The spool 62 is supported in the left half position in the figure by
b, and when there is pressure on this spool from port 62c, this applies a downward force in the figure to hold spool 62b in this position. While there is no pressure inflow from port 62c, port 62c
When pressure is supplied to port 62, this pressure
Increase the output pressure from e. This output pressure is in the chamber 62f
When the spool 62b is fed back to a value corresponding to the spring force of the spring 62a, the spool 62b is moved to the right half position in the figure, and the ports 62d and 62e are cut off.
The overrun clutch pressure reducing valve 62 is connected to the port 62e.
It is assumed that the output pressure from the spring 62a is reduced to a constant value determined by the spring force of the spring 62a. The 2-speed servo apply pressure accumulator 64 is constructed by elastically supporting a stepped piston 64a at the left half position in the figure by a spring 64b, and a chamber 64c defined between both ends of the stepped piston 64 is opened to the atmosphere. The small-diameter end face and large-diameter end face of the attached piston are respectively placed in sealed chambers 64.
d, 64e. The 3-speed servo release pressure accumulator 66 includes a stepped piston 66a elastically supported in the left half position in the figure by a spring 66b, and a chamber 66c defined between both ends of the stepped piston is connected to the line pressure circuit 78. The small-diameter end face and large-diameter end face of the stepped piston face the closed chambers 66d and 66e, respectively. The 4-speed servo apply pressure accumulator 68 is constructed by elastically supporting a stepped piston 68a at the left half position in the figure by a spring 68b, and defines a sealed chamber 68c between both ends of the elastic piston. The small diameter end face and the large diameter end face are sealed in sealed chambers 68d and 68, respectively.
Let's face e. Accumulator control valve 70 has spring 70
The spool 7 is supported in the left half position in the figure by a.
0b, and the spool 70b is remote from the spring 70a.
The control pressure of the circuit 81 is introduced into the chamber 70c facing the end face of the circuit 81. The spool 70b connects the output port 70d to the drain port 70e at the left half position in the figure, and the spool 70b connects the output port 70d to the drain port 70e, and
When the control pressure increases and the spool 70b rises above the right half position in the figure, the port 70d is switched and connected to the line pressure circuit 78. and,
The output port 70d is connected to the accumulator chambers 64d and 68c by the circuit 111, and the spring 70
It is also connected to the chamber 70f that accommodates a. Thus, the accumulator control valve 70 raises the spool 70b above the right half position in the drawing by the control pressure applied to the chamber 70c except when the reverse movement is selected. As a result, the line pressure from the circuit 78 is output to the circuit 111, and when the pressure in the circuit 111 reaches a value corresponding to the control pressure, the spool 70b is elastically supported at the right half position in the figure. This is why circuit 11
The pressure of 1 is regulated to a value corresponding to the control pressure, but
Since the control pressure increases as the engine load (engine output torque) increases except when reverse is selected as described above, the accumulators 64 and 68 are removed from the circuit 111.
The pressure supplied to the chambers 64d and 68c as accumulator back pressure also increases as the engine output torque increases. In addition, since the control pressure is 0 when the reverse movement is selected, no pressure is output to the circuit 111. Next, to provide a supplementary explanation of the hydraulic circuit network, the circuit 106 extending from the port 36D of the manual valve 36 connects the port 38g of the first shift valve 38 and the second port 38g of the first shift valve 38.
While connecting to port 40g of shift valve 40,
It is also connected to port 56c of shuttle valve 56 and port 58g of overrun clutch control valve 58 via circuit 112 branched from circuit 106. The port 38f of the first shift valve 38 is connected to the circuit 11
3 to the port 50f of the 4-2 relay valve 50, and also to the accumulator chamber 64e and the 2-speed servo apply chamber 2S/A via the one-way orifice 114.
15, it is also connected to the chamber 32c of the shuttle valve 32. Further, the port 38h of the first shift valve 38 is connected to the chamber 50e of the 4-2 relay valve 50 and the port 58h of the overrun clutch control valve 58 by a circuit 116, and the port 50c of the 4-2 relay valve 50 is connected to the chamber 50e of the 4-2 relay valve 50 by a circuit 117. Connected to port 40k of 2-shift valve 40. The ports 38k and 38l of the first shift valve 38 are connected to the port 4 of the second shift valve 40.
High clutch H/C by circuit 118 along with 0f
A pair of one-way orifices 119 and 120 arranged in opposite directions are inserted in the middle. A circuit 121 branched from the circuit 118 between these orifices and the high clutch H/C
is connected to the 3-speed servo release chamber 3S/R and the accumulator chamber 66 via the one-way orifice 122.
ports 48c and 48d are connected to the circuit 123 that bypasses the one-way orifice 122, and the 3-2 timing valve 48 is connected to the circuit 123 that bypasses the one-way orifice 122.
Insert into 3. A circuit 124 branched from the circuit 121 between the one-way orifice 122 and the 3-speed servo release chamber 3S/R is connected to the chamber 52e of the 4-2 sequence valve 52, and the ports 52c and 52f of the 4-2 sequence valve 52 are connected to the first Port 38i of shift valve 38 and second shift valve 40
Connect to port 40h of Port 38j of first shift valve 38 is connected to circuit 125
The port 38d is connected to the port 40d of the second shift valve 40 by the circuit 126, and the port 38d is connected to one inlet port of the shuttle ball 127 by the circuit 126. The other inlet port of shuttle ball 127 is connected to circuit 12.
8 is connected to the port 36R of the manual valve 36 together with the circuit 77 on the one hand, and to the reverse clutch R/C and the accumulator chamber 68d via the one-way orifice 129 on the other hand, and the outlet port of the shuttle ball 127 is connected to the port 36R of the manual valve 36 through the circuit 130. Connect to low reverse brake LR/B.
The port 40j of the second shift valve 40 is connected to the port 54c of the range pressure reducing valve 54 and the chamber 5 by the circuit 131.
4f and the port 54 of the range pressure reducing valve 54.
d is connected to port 36 of manual valve 36 by circuit 132. Port 56e of shuttle valve 56 is connected by circuit 133 to chamber 48e of 3-2 timing valve 48, and port 56d is connected by circuit 134 to chamber 58c of overrun clutch control valve 58. Overrun clutch control valve 58
The port 58d is connected to the accumulator chamber 66d by a circuit 135, and also connected to the accumulator chamber 68e and the 4-speed servo apply chamber 4S/A via a one-way orifice 136. Port 58f of overrun clutch control valve 58 is connected to port 62d of overrun clutch pressure reducing valve 62 by circuit 137, port 62e of pressure reducing valve 62 is connected to overrun clutch OR/C by circuit 137, and port 62e of overrun clutch pressure reducing valve 62 is connected to overrun clutch OR/C by circuit 137. ，
A check valve 139 is provided between 138 and 138. Port 62c of overrun clutch pressure reducing valve 62 is connected to port 36 of manual valve 36 by circuit 140.
and connected to the chamber 56g of the shuttle valve 56. By the way, FIG. 4 is a schematic diagram of a transmission control device 200 showing an embodiment of the present invention, in which a vehicle speed sensor 201
and a throttle sensor 202, and a vehicle speed sensor 2
01 detects the vehicle speed, and the throttle sensor 202 detects the engine load, and these detection signals are used as shift signals for determining the shift point. The signals from both the sensors 201 and 202 are input to the calculation means 204 of the microcomputer 203, and the signals are driven to the first and second shift solenoids 42 and 44 according to the predetermined shift pattern shown in FIG. It is designed to output a signal. By the way, the microcomputer 203 is provided with a correction means 205, and this correction means 205 receives the temperature from the oil temperature sensor 206 that detects the temperature of the hydraulic oil of the hydraulic pressure control device A as the temperature corresponding to the warm-up state of the engine. A signal is now being input. The correction means 205 corrects the vehicle speed signal from the vehicle speed sensor 201 based on the temperature signal, and outputs this correction signal to the calculation means 204. FIG. 6 shows a flowchart for executing a program to be processed by the microcomputer 203. First, the vehicle speed (Vsp) and throttle opening (Th) as shift signals are read in step by step. Next, the oil temperature (To) is read in a step, and a correction coefficient (T _R ) is calculated in a step based on this oil temperature output. This correction coefficient (T _R ) is determined in accordance with the data map shown in FIG. 7, for example, which is stored in the correction means 205 in advance. That is, this data map is set in stages such that the correction coefficient (T _R ) is small (T _R =0.5) when the temperature is low and becomes large (T _R =1.5) when the temperature is high. When the correction coefficient (T _R ) is calculated in the step in this way, the correction value (Vspx=Vsp・T _R ) for the vehicle speed (Vsp) is calculated in the step, and this correction signal is output to the step. In this step, the gear position (Gp) is determined according to the shift pattern shown in FIG.
That is, in the shift pattern shown in FIG. 5, the solid line is the shift boundary line for upshifting, the broken line is the shift boundary line for downshifting, and the plot points of the throttle value (Th) with respect to the correction value (Vspx) are the respective plot points. When the shift boundary line is crossed, the gear is shifted up or down. When the gear position (Gp) is determined in this way, a drive signal is output from the step to the first and second shift solenoids 42 and 44 of the hydraulic pressure control device based on this gear position. It's summery. That is, drive signals to the first and second shift solenoids 42 and 44 are outputted as shown in Table 3 above to operate the first and second shift valves 38 and 40. In this way, in this example, the oil temperature (To)
The vehicle speed signal (Vsp) is corrected in accordance with ) can substantially change the shift schedule along the shift pattern shown in _FIG . In other words, when the oil temperature (To) is low, the correction coefficient (T _R ) is
is as small as 0.5, the correction signal (Vspx) decreases, and the actual vehicle speed when passing the shift boundary line increases. In other words, the shift points for upshifting and downshifting at low temperatures are shifted to the high engine speed side, and, for example, overdrive settings from 3rd to 4th gears are possible at high engine speeds when the engine rotation is stable. As a result, engine operation will not become unstable due to excessively shifting to a high gear at low temperatures, and overdrive control will be possible when driving at high speeds, improving driving performance and fuel efficiency. . The gear position is determined using the vehicle speed signal (Vsp) and the throttle opening signal (Th) as parameters, as described above, but as is clear from FIG. 5, if the throttle opening signal (Th) Even if it is corrected by the oil temperature (To), the shift point does not move on the low load side and the correction effect cannot be obtained. On the other hand, as mentioned above, the vehicle speed signal (Vsp)
By correcting this, it is possible to shift the high speed point in accordance with the temperature over the entire operating range. Furthermore, in this example, when the oil temperature (To) is high, the correction coefficient (T _R ) is as large as 1.5, so the engine speed at the high speed point is set low, contrary to the case when the oil temperature is low. This reduces engine load and prevents overheating. It goes without saying that the map data shown in FIGS. 7 and 5 is not limited to this, and the correction coefficient characteristics and shift boundary line characteristics can be set in accordance with each engine. Furthermore, in this embodiment, the oil temperature (To) of the hydraulic pressure control device is detected as the operating temperature that affects the vehicle operating temperature, and the shift schedule is changed based on this oil temperature. In addition to this oil temperature, the engine wall temperature, cooling water temperature, catalyst temperature, etc. may be detected as the operating temperature. Furthermore, in the embodiment described above, the entire shift schedule of the shift pattern shown in FIG. It may be possible to change only →3rd gear or 3rd →4th gear. Effects of the Invention As explained above, in the shift control device for an automatic transmission of the present invention, the vehicle speed signal, which is the basis of shift control, is corrected according to the operating temperature, and the vehicle speed signal is corrected according to a predetermined shift pattern set in advance. Therefore, since the gears are determined based on the above correction signal, it is possible to use all the gears of the automatic transmission in the range where the engine rotation is stable no matter what the temperature conditions are. Become. Therefore, it is possible to use the highest speed gear when driving at high speed while ensuring stable operation of the engine at low temperatures, and it is possible to improve noise and fuel efficiency. Furthermore, in the present invention, instead of changing the shift pattern itself with vehicle speed as a parameter depending on temperature, the vehicle speed signal is corrected based on temperature to substantially shift the shift point. There is no need to store a large number of shift patterns, which is advantageous in terms of memory capacity and simplification of control. Moreover, even if the displacement of the engine combined with the automatic transmission differs, it can be handled simply by matching the vehicle speed signal correction characteristics without changing the shift pattern itself, making it extremely easy to adapt to a large number of vehicle models. Become.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the concept of a shift control device for an automatic transmission of the present invention, and FIG. 2 is an overall circuit diagram showing an embodiment of a hydraulic pressure control device for an automatic transmission in which the shift control device of the present invention is used. 3 is a schematic diagram showing an embodiment of the power transmission train of an automatic transmission to which the hydraulic pressure control device shown in FIG. 2 is applied, and FIG. A system diagram showing one embodiment, FIG. 5 is a characteristic diagram showing one embodiment of the shift pattern used in the present invention, and FIG. 6 is a flowchart of one embodiment for executing the program of the shift control device shown in FIG. 4. FIG. 7 is a characteristic diagram showing one embodiment of the correction coefficient used in the speed change control device of the present invention. 200...Shift control device, 201...Vehicle speed sensor (shift signal), 202...Throttle sensor,
203...Microcomputer, 204...Calculating means, 205...Correction means, 206...Oil temperature sensor (temperature detection means).

Claims (1)

[Claims] 1. By means of a shift signal including at least a vehicle speed signal,
In an automatic transmission in which a gear position is determined according to a preset gear shift pattern and a gear change is performed in accordance with the gear position, a temperature detection means for detecting a temperature corresponding to a warm-up state of an engine; A correction means for correcting the vehicle speed signal based on a signal from the detection means and outputting the correction signal, and determining a gear position from the shift pattern based on the correction signal output from the correction means. A speed change control device for an automatic transmission, characterized in that: