JPH03186658A - Speed change control device of automatic transmission - Google Patents

Abstract

PURPOSE:To prevent deterioration of durability due to accumulation of heat in a specific part by forcedly executing a normally inhibited upshift, when a condition with a rotary member rotated at a high speed is long continued, even in a shift range where the upshift is inhibited from a predetermined speed change shift. CONSTITUTION:A means for deciding whether a shift range is an upshift inhibiting range of inhibiting a shiftup from a predetermined speed change shift, such as setting a rotary speed of a specific rotary member to a high speed, or not, means for deciding whether the present speed change shift is the predetermined speed change shift or not and a means for deciding whether running in the predetermined speed change shift is continued for not less than a predetermined time or not, when the present speed change shift is the predetermined speed change shift, are provided. A means is provided for executing an upshift even when any more upshift is normally inhibited in the shift range, if the shift range is an upshift inhibiting range, in the case of the running in the predetermined speed change shift continued for not less than the predetermined time.

Description

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

The present invention provides an automatic transmission comprising first and second transmission sections arranged in series, and configured to achieve multi-speed shifting by switching the first and second transmission sections simultaneously or alternately. The present invention relates to a speed change control device.

[Conventional technology]

With the rapid increase in the length of automatic transmissions for vehicles in recent years, the first transmission section that can automatically change gears is equipped with a so-called gear ratio of 1 or less, mainly with the intention of improving fuel efficiency. In many cases, an overdrive device is installed in series as a second transmission section. In addition, such a second transmission section is actively synchronized with the speed change of the first transmission section, so that the difference in gear ratio between the first transmission section and the first transmission section, which has a relatively large difference in gear ratio between each gear stage, is comparatively balanced. By simultaneously or alternately shifting the vehicle and the second transmission section, a multi-speed shift of six forward speeds is achieved by controlling the speed change as shown in section A of Fig. 3, for example. Some things are already known (for example, Japanese Patent Application Laid-open No. 57-37140)
. By doing so, it is possible to easily realize multi-stage speed change and obtain many advantages such as improved fuel efficiency, improved power performance, and reduced burden on the friction stop device. However, in such an automatic transmission, the first
Since the second transmission section switches for each gear stage of the transmission section,
The rotational speed of certain parts, which was not a problem in the past, sometimes becomes extremely high, and if this high rotational state continues for a long time, cooling due to lubrication becomes insufficient, and ripeness accumulates, causing damage to the surrounding area. A problem may occur in which the durability of members (for example, pinion shafts, bearings, etc.) decreases. In view of such problems, Japanese Patent Laid-Open No. 62-2051 discloses a technique in which an upshift is performed when a predetermined gear position continues for a predetermined time or longer in a forward range.

[Problem to be solved by the invention]

However, continuation of high-speed rotation of such rotating members actually becomes a problem in the 2nd range and L range among the forward ranges.
In many cases, the driving range is other than the drive range, such as range, but in the conventional example described above, this point has not been sufficiently examined, and regardless of whether the shift range is the drive range, or the 2-range or palm range, etc. Because the same control was applied regardless of the situation (all treated as forward ranges), there was a problem that the effect may not be brought out properly in the 2nd range or L range when the true effect is expected. Ta. In other words, in the case of a drive range, even if there is a gear position where the rotational speed of some rotating members is high, upshifts from that gear position are originally allowed, so the automatic transmission is Normally, it is not possible to maintain this gear for a long time, and even if it were to be maintained in this gear for a relatively long time, it would not mean that the gear would not upshift. This means that the vehicle speed is not so high as to exceed the upshift line, and therefore, it can be said that the rotational speed of the rotating member is not at such a high speed that durability becomes a problem. However, in the case of 2 range or L range, upshifting beyond a certain gear is prohibited.
Therefore, it can be said that there is a very high possibility that the predetermined gear position where upshifting is prohibited will be maintained for a long time. Moreover, not only is there a high possibility that this will be maintained for a long time, but also because upshifting is prohibited no matter how high the vehicle speed becomes, the rotational speed of the rotating member will also be proportional to the increase in vehicle speed. This can lead to a significant increase in Therefore, if the predetermined gear position in which this upshift is prohibited is a gear position in which the rotational speed of some rotating members is likely to increase, the durability of the surrounding members of this rotating member (for example, Even for a short period of time, it is possible to be placed under very severe conditions. However, the conventional technology described above did not take this into consideration, and because the drive range, 2nd range, and L range were all controlled using the same flow due to the "forward range," the control was half-hearted. However, there was a problem in that the desired effect may not be obtained when it should be expected. The present invention has been made in view of such conventional problems, and when driving in a driving range in which upshifting beyond a predetermined gear is prohibited, Even when driving in a gear for a long period of time, an automatic system that can prevent the durability of surrounding components that rotate at high speeds from decreasing due to excessive heat load. An object of the present invention is to provide a speed change control device for a transmission.

[Means to solve the problem]

As summarized in FIG. 1, the present invention comprises first and second transmission sections arranged in series, and multi-stage transmission is achieved by switching the first and second transmission sections simultaneously or alternately. In a shift control device for an automatic transmission configured to achieve this, the shift range is an upshift prohibition range that prohibits upshifting from a predetermined gear position where the rotational speed of a specific rotating member becomes high. means for determining whether or not the current gear is the predetermined gear; and means for determining whether the current gear is the predetermined gear; means for determining whether or not driving has continued for a predetermined period of time or longer; The above object has been achieved by providing means for executing upshifts even if further upshifts are normally prohibited.

[Effect]

In the present invention, the shift range is a range in which upshifting beyond a predetermined gear is prohibited, and the predetermined gear is a gear where the rotational speed of some rotating members is high. If the vehicle continues to operate in the specified gear for a specified period of time, the upshift will be executed as an exception, even if further upshifts are normally prohibited in the shift range. I try to do that. As a result, the rotating member is prevented from continuing to rotate at high speed, and it is possible to prevent the durability of peripheral members such as bearings from decreasing.

【Example】

Embodiments of the present invention will be described in detail below based on the drawings. FIG. 2 shows an overall outline of a vehicle automatic transmission to which this embodiment is applied. This automatic transmission includes a torque converter 20, a second transmission section 40, and a first transmission section 60 with three forward speeds and one reverse speed. The torque converter 20 includes a pump 21 and a turbine 2.
2, a stator 23, and a lock-up clutch 24. The pump 21 is connected to the crankshaft 10 of the engine 1, and the turbine 22 is connected to a carrier 41 of a planetary gear device in the second transmission section 40. In the second transmission section 40, a planetary binion 42 rotatably supported by the carrier 41 meshes with a sun gear 43 and a ring gear 44. or,
A clutch Co is provided between the sun gear 43 and the carrier 41.
and one-way clutch Fo are provided, and sun gear 4
A brake Be is provided between the housing HU and the housing HU. The first transmission section 60 is provided with two rows of planetary gears, one on the front side and the other on the rear side. This planetary gear device includes a common sun gear 61, ring gear 62.63, planetary pinion 64.65,
and carrier 66.67. A ring gear 44 of the second transmission section 40 is connected to the ring gear 62 via a clutch C1. Further, a clutch C2 is provided between the ring gear 44 and the sun gear 61.
is provided. Further, the carrier 66 is connected to the ring gear 63, and the carrier 66 and the ring gear 63 are connected to the output shaft 70. On the other hand, a brake B3 and a one-way clutch F2 are provided between the carrier 67 and the housing Hu, and a brake B2 is further provided between the sun gear 61 and the housing Hu via the one-way clutch F1. Furthermore, a brake B1 is provided between the sun gear 61 and the housing Hu. This automatic transmission is equipped with a transmission section as described above, and receives signals from a throttle sensor 100 that detects the throttle opening that reflects the load condition of the engine 1, a vehicle speed sensor 102 that detects vehicle speed, etc. The central processing unit (ECU) 104 drives and controls the electromagnetic solenoid valves S1 to S3 and sL in the hydraulic control circuit 106 according to a preset shift pattern, as shown in part B of FIG. , the clutches, brakes, etc. are combined to perform speed change control. In addition, in FIG. 3, the fourth far stage of the drive range is written as 0, indicating that this gear stage may be cut and used. Further, in FIG. 3, the circle mark indicates a stopped state, and the X mark indicates a stopped state only when the engine brake is used. As shown in FIG. 4, the electromagnetic valves S4 and S2 control the first and second shift valves of the first transmission section 6o, and the electromagnetic valve S3 controls the second shift valve of the second transmission section 40. The third shift valve IIJ# switches between the high speed side and the low speed side of the engine, and the electromagnetic solenoid pulp sL controls the locking clutch 24 of the torque converter 20, respectively. Furthermore,
The linear solenoid valve SO can arbitrarily control the brake Bo and other hydraulic pressures. Note that the specific fg rules and operations of each device within the hydraulic control device are not particularly different from those of the prior art. In FIG. 2, reference numeral 110 is a shift position sensor, and the shift lever operated by the driver is set to N (neutral), D (drive), 3 (third), 2 (second), L (low), and R (reverse). , P (parking), etc.; 112 is a pattern select switch for selecting E (economical driving), P (power driving), etc.; and 114 detects the engine cooling water temperature. 116 is a foot brake;
Reference numeral 118 indicates a brake switch that detects the operation of the handbrake. FIG. 5 shows a collinear diagram of each rotating member of the automatic transmission according to this embodiment. This collinear diagram is shown when the input shaft rotation speed (turbine rotation speed) of the automatic transmission is the same at each gear stage The rotational speed of each rotating member is shown. From this FIG. 5, in the second gear stage, the rear side binion 6 of the first transmission section
It can be seen that the rotation speed of No. 4 is considerably faster than before. That is, when comparing the first speed and the second speed, the sun gear 61 rotates in the opposite direction by N1 in FIG. 5, based on the carrier 66 of the rear planetary gear device. However, in the case of the second gear, the rotation speed M of the clutch C1
As CI increases, this reverse rotation increases to N2. The rear side binion 64 applies Z s / Z to this N2.
It will rotate by the amount multiplied by p. Here, z9
．． zP has sun gear 61 and planetary binion 6, respectively.
It is a fraction of 4. As described above, in the second speed stage, the rotational speed of the rear planetary binion 64 increases considerably compared to the conventional one, which may pose a problem in the durability of the binion shaft and bearings. By the way, when the shift range of the automatic transmission is set to 2 ranges, as is clear from FIG. 3, the automatic transmission cannot upshift from the second gear to the third gear. Therefore, in this embodiment, the following measures are taken to prevent problems when the shift range is 2 range (or L range) and the vehicle is driven in 2nd gear for a long time. It was designed to take the following. FIG. 6 shows a control flow executed by the apparatus of the above embodiment. First, in step 200, it is determined whether the shift range is in the first range or the second range. If the shift range is the L range or a driving range other than the 2nd range, the main control from step 202 onwards is bypassed (timer reset in step 216: described later). In this case, for example, in the case of D range or 3 range, upshifting to 3rd gear or higher is basically allowed in the shift pattern, so upshifting to 2nd gear or higher is basically allowed. This is because it is unusual for people to be able to maintain this condition for such a long time. Moreover, even if maintained,
Since the vehicle speed does not exceed the upshift line to the third gear, the rotational speed of the rear planetary pion 64 does not rise above the value corresponding to the upshift line to the third gear. This is because it is understood that there is no particular problem. In addition to the 2nd range, the L range is also taken into consideration here. Although upshifting to the 2nd gear is prohibited in the L range, for example, when the vehicle is shifted from a high vehicle speed state to the L range, This is because the engine may be in the second gear state at the beginning of the manual shift in order to prevent the engine from reaching an extremely high speed state. In step 202, it is determined whether the current gear is the second gear. If it is in 1st gear,
This control is bypassed since a high rotational state of the rotating member does not occur in the first place (timer reset=f&description in step 216). When the current gear is 2nd gear, the rear planetary pinion 64 is in a high rotation state, and no matter how much the vehicle speed increases, the gear shift pattern does not allow any further upshifts, so the bearings, etc. Since there is a possibility that heat may be accumulated in the cylinder and the durability may be deteriorated, the main control from step 204 is started. In step 204, it is determined whether the vehicle speed No is greater than the threshold value No'. Vehicle speed is threshold value N. If it is smaller, this control is bypassed (step 2
Reset the timer at 16 (described later). On the other hand, when it is determined that the shift range is the 2 range or the L range, the vehicle is in the second gear, and the vehicle speed is greater than the threshold value No', the process proceeds to step 206 and the value of the flag F is determined. This flag F indicates that the timer is activated, and since it is not initially activated, the process proceeds to step 208, where the timer is activated and flag F is set to 1. Thereafter, in step 210, it is determined whether the elapsed time T1 since the timer was activated has become greater than a predetermined time TI'. As long as the elapsed time T1 since the timer was activated is less than the predetermined time T+', the timer is reset and the flow is repeated from the beginning. If there is no particular change in any of the conditions of the shift range, current gear, or vehicle speed, the elapsed time T will eventually reach the predetermined time T after several repetitions.
' or higher, the process proceeds to step 212, where an upshift is commanded from the second gear to the third gear (or a higher gear), and the high rotational state of the rear planetary pinion is resolved. It has become so. Thereafter, flag F is reset to 0 in step 214. If the shift range deviates from the L range or 2 range, if the current gear is no longer the second gear, or if the vehicle speed No. becomes smaller than the threshold value No', the timer T1 is reset in step 216, and the flag F is reset. is now reset to zero. FIG. 7 shows a modification of step 216 in FIG. In step 216 of FIG. 6, if any of the three conditions of the shift range, current gear, and vehicle speed are off, the timer T1 is immediately reset. If the three conditions come together again, the history up to that point will be completely ignored. Therefore, the flow shown in FIG. 7 solves this problem more rationally. That is, when a negative determination is made in either step 200, 202, or 204, the process proceeds to step 216A, where the value of flag F is determined. If the value of flag F is 0, that is, if timer T1 is not activated at all, step 2
Proceeding to step 16D, the control flow is substantially the same as that shown in FIG. 6. Next, when the flag F is 1, that is, when it is determined that the timer T1 is in the process of being activated, the process proceeds to step 216B, where the second timer T2 is activated, and the flag F is set to a 34:8 constant. Try again. In step 216C, the second timer T2, that is, the progress from the time when the shift range is changed to the 2nd range, the current gear is no longer the 2nd gear, or the vehicle speed NO becomes lower than the threshold value N o ''. Time T2 is a predetermined value 'r2
′ is determined. Then, while this elapsed time T2 is shorter than the predetermined value T2', step 216
D is bypassed and timer T1 is not reset. However, when it is determined that the elapsed time since the condition is no longer met is longer than the predetermined time T2', the timers (both Tl and T2) are reset, and when the first three conditions are satisfied, the timer is reset again. This is the start of a new run 1~. According to the control flow shown in FIG. 7, for example, even if the vehicle is temporarily out of second gear or the vehicle speed decreases, the predetermined time T
Since the timer reset is not performed until two elapses, it is possible to prevent heat from gradually accumulating, for example, when the vehicle speed No. increases or decreases around the threshold value No'. In addition, in this control flow, only one type of threshold value No' was provided for the vehicle speed No, but this may be divided into a starting vehicle speed No' and a reset vehicle speed Noll to give hysteresis to the control. . Fig. 8 shows a shift diagram in two ranges when this control is executed. In Fig. 8, "No" corresponds to the vehicle speed threshold, and if the vehicle speed continues to be higher than this for a predetermined time T1', the An upshift from the second gear to the third gear is realized. In this case, the downshift point from the third gear to the second gear is set slightly lower than the threshold value No'. Therefore, the system does not return to the second gear unless the vehicle speed decreases to a certain degree.In addition, the downshift line from the fifth gear to the second gear is drawn in Figure 8. When manually shifting to 2nd gear from a very high vehicle speed, the engine is first shifted to 5th gear to prevent engine overspeed, and then shifted to 3rd gear (and then 2nd gear) as the vehicle speed decreases. ).In the above embodiment, one of the conditions for forced upshift is that the vehicle speed is higher than a predetermined threshold value N o '' to ensure more accurate control. However, in the present invention, it is not necessary to consider that the vehicle speed is higher than a predetermined threshold value as an essential condition. In this case, the present invention makes it an essential condition that the current gear is a predetermined gear (a gear where further upshifts are prohibited), so the upshift line to the predetermined gear is The corresponding vehicle speed will serve as a practical threshold value for the vehicle speed.

【Effect of the invention】

As explained above, according to the present invention, even if the shift range is such that upshifting is prohibited from a certain gear position, the rotating member of the automatic transmission can rotate at a very high speed. When this condition continues for a long time, upshifts, which are normally prohibited, are forced to occur, which causes heat to accumulate in certain parts of the automatic transmission, reducing its durability. An excellent effect can be obtained in that it becomes possible to prevent the occurrence of.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the gist of the present invention, and FIG. 2 is a block diagram showing the gist of the present invention.
A schematic block diagram of a vehicle automatic transmission to which the present invention is applied; FIG. FIG. 4 is a block diagram schematically showing the input/output relationship of the automatic transmission and the hydraulic control device. FIG. 5 is a collinear diagram showing the rotational speed of each rotating member when the turbine rotational speed of the automatic transmission is the same; FIG. 6 is a flowchart showing a control flow executed by the central processing unit; FIG. 7 is a partial flow chart in which a part of the control flow in FIG. 6 is changed, and FIG. 8 is a diagram showing an example of a shift pattern in two ranges employed in the above control flow. 40... Second transmission section, 60... First transmission section, 110... Shift position sensor, N,... Vehicle speed, 64... Rear side planetary binion (in second gear) (Rotating members whose rotational speed may be very high), T+, T2...Timer. Fig. 1 Fig. 5 Fig. 1--3rd nd -・□0/D (6th) th --, --+st Fig. 7 Doctor (to the Soviet Union) Fig. p'L

Claims (1)

[Claims] (1) Shifting of an automatic transmission comprising first and second transmission sections arranged in series and configured to achieve multi-stage shifting by switching the first and second transmission sections simultaneously or alternately. In the control device, means for determining whether or not the shift range is an upshift prohibition range that prohibits upshifting from a predetermined gear position where the rotational speed of a specific rotating member becomes high; means for determining whether or not the gear is at the predetermined gear; and when the current gear is at the predetermined gear, determining whether or not running in the predetermined gear continues for a predetermined time or more. means for determining, and if driving in the predetermined gear continues for a predetermined time or more when the shift range is in the upshift prohibition range, performs an upshift that is normally prohibited in the shift range; A speed change control device for an automatic transmission, comprising: means;