JPH078631B2 - Control device for transmission and fuel cut device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an engine with a fuel cut device and a continuously variable or stepless automatic transmission having downshift means for downshifting the transmission when engine braking is required. Machine,
The present invention relates to a control device for a transmission and a fuel cut device when combined with each other.

(B) Conventional technology As a control device for a conventional continuously variable transmission, Japanese Patent Publication No. 59-3490
There is one shown in Japanese Patent Publication No. 4. The purpose of this control device is to obtain the engine braking effect when the accelerator pedal depression amount becomes 0, and when the accelerator pedal depression amount becomes 0, the gear ratio in the normal case is obtained. A constant engine brake instruction signal is added to the instruction signal. With this, when the accelerator pedal depression amount is set to 0, the gear ratio becomes a predetermined value larger than the minimum gear ratio, and the engine braking effect can be obtained.

(C) Problems to be Solved by the Invention However, the above control device has the following problems. When this continuously variable transmission is combined with an engine equipped with a fuel cut device that stops the supply of fuel in the engine braking state, the shock when releasing the engine braking state and accelerating again increases. This is because the shift shock accompanying the shifting of the continuously variable transmission and the rise of engine torque accompanying the restart of fuel supply to the engine due to the release of the fuel cut device occur simultaneously. This is because the shock will increase.
That is, if the accelerator pedal depression amount is increased from the engine braking state where the accelerator pedal depression amount is 0, the instruction signal added for engine braking in the continuously variable transmission is released, so that the gear ratio is large. From the gear ratio to the small gear ratio state occurs. At the same time, in the engine, due to the increase in the accelerator pedal depression amount, the operation of the fuel cut device is released, the fuel supply is restarted, the engine generates torque, and the engine is driven from the reverse drive state up to now. Change to a state. Both the shift of the continuously variable transmission and the generation of engine torque cause a shock to the vehicle, but these are simultaneously generated when the accelerator pedal is depressed, resulting in a large shock.
Further, the control device shown in the above publication has the following incidental problems. That is, the instruction signal to be added to obtain the engine braking effect is always a constant value, but the instruction signal is increased so that the sufficient engine braking effect can be obtained even at a low vehicle speed (that is,
If the change in the gear ratio is made large), a rapid gear shift is performed when the accelerator pedal depression amount is returned to 0 at high vehicle speed, and a large gear shift shock is generated. A large shift shock also occurs when releasing the engine braking state. On the contrary, if the instruction signal for engine braking is reduced to reduce the change in the gear ratio, the engine braking effect becomes insufficient in the low vehicle speed state. The present invention aims to solve the above problems.

(D) Means for Solving the Problems The present invention sets a time difference between the release of the operation of the fuel cut device and the shift of the continuously variable transmission when the accelerator pedal depression amount is increased from the engine braking state. By preventing both torque fluctuations from occurring at the same time, the above problem is solved. That is, the control device for the transmission and the fuel cut device according to the present invention is in a state where the fuel cut device stops the fuel supply to the engine and the downshift means shifts the transmission to the downshift side. When the restart of the fuel supply and the release of the shift state to the downshift side are simultaneously instructed by, the time difference setting means for setting a predetermined time difference between the restart of the fuel supply and the release of the shift state to the downshift side. Is provided. The signal for moving the gear ratio of the downshift device to the large side can be appropriately changed in accordance with the vehicle speed.

(E) Action When the accelerator pedal is depressed with the accelerator pedal depressed by 0 while the vehicle is running with the accelerator pedal depressed by a predetermined amount, the gear ratio of the continuously variable transmission is greater than the minimum gear ratio due to the operation of the downshift means. The value becomes a predetermined value, and the fuel cut device is activated to stop the supply of fuel to the engine.
As a result, the engine braking effect can be obtained.
If the amount of depression of the accelerator pedal is increased with the intention of re-accelerating from this state, the operation of the fuel cut device is stopped first, and the supply of fuel to the engine is started. This causes the engine to generate torque. This engine torque fluctuation causes a small shock.
Next, after the time set by the time difference setting means has passed, the operation of the downshift means is released, and the continuously variable transmission shifts in the upshift direction from the high gear ratio state for engine braking. A small shock is also generated during this shift. As described above, the shock due to the torque fluctuation of the engine and the shock due to the shift of the continuously variable transmission occur with a predetermined time difference, and the individual shocks are not so large. For this reason, the shock is not so great as to affect the riding comfort. Further, by setting the operation amount of the downshift means to be appropriate according to the vehicle speed, it is possible to obtain an appropriate engine braking effect without generating an excessive shock over the entire vehicle speed.

(F) Embodiment FIG. 2 shows a power transmission mechanism of a continuously variable transmission. This continuously variable transmission has a fluid coupling 12, a forward / reverse switching mechanism 15, a V
It has a belt type continuously variable transmission 29, a differential device 56, etc.,
Output shaft 10a of engine 10 with fuel cut device 11
Can be transmitted to the output shafts 66 and 68 at a predetermined gear ratio and rotation direction. The fuel cut device 11
Is a device capable of stopping the fuel supply in a predetermined operating state, that is, when the throttle is fully closed and the engine rotation speed (or vehicle speed) is a predetermined value or more. This continuously variable transmission is equipped with a fluid coupling 12 (lockup oil chamber 12
a, a pump impeller 12b, a turbine runner 12c, etc.), a rotary shaft 13, a drive shaft 14, a forward / reverse switching mechanism 15, a drive pulley 16 (a fixed cone plate 18, a drive pulley cylinder chamber 20).
(Chambers 20a and 20b), movable cone plate 22, groove 22a, etc.), planetary gear mechanism 17 (sun gear 19, pinion gear 21,
Pinion gear 23, pinion carrier 25, internal gear 27, etc.), V belt 24, driven pulley 26 (consisting of fixed conical plate 30, driven pulley cylinder chamber 32, movable conical plate 34, etc.), driven shaft 28, for forward movement Clutch 40, drive gear 4
6, idler gear 48, reverse brake 50, idler shaft 5
2, pinion gear 54, final gear 44, pinion gear 5
8, the pinion gear 60, the side gear 62, the side gear 64, the output shaft 66, the output shaft 68, and the like, but detailed description thereof will be omitted. Regarding the structure of the part of which description is omitted, Japanese Patent Application No. 59-
No. 226706.

FIG. 3 shows a hydraulic control device for a continuously variable transmission. This hydraulic control device includes an oil pump 101, a line pressure regulating valve 102, a manual valve 104, a shift control valve 106, an adjusting pressure switching valve 108, a shift motor (step motor) 110, a shift operating mechanism 112, a throttle valve 114, a constant pressure. It has a pressure regulating valve 116, a solenoid valve 118, a coupling pressure regulating valve 120, a lock-up control valve 122, etc., which are connected to each other as shown in the drawing, and also have a forward clutch 40, a reverse brake 50, The fluid coupling 12, the lockup oil chamber 12a, the drive pulley cylinder chamber 20, and the driven pulley cylinder chamber 32 are also connected as shown. Detailed description of these valves and the like will be omitted. The parts omitted from the explanation are the above-mentioned Japanese Patent Application No. 59-
No. 226706. Each reference numeral in FIG. 3 indicates the following member. Pinion gear 110a, tank 130,
Strainer 131, oil passage 132, relief valve 133, valve hole 134, ports 134a-e, spool 136, lands 136a-b, oil passage 13
8, one-way orifice 139, oil passage 140, oil passage 142, one-way orifice 143, valve hole 146, ports 146a-g, spool 14
8, lands 148a-e, sleeve 150, spring 152, spring 154, pressing member 158, oil passage 164, oil passage 165, orifice 166, orifice 170, valve hole 172, ports 172a-e,
Spool 174, land 174a-c, spring 175, oil passage 17
6, orifice 177, lever 178, oil passage 179, pin 181, rod 182, land 182a-b, rack 182c, pin 183, pin
185, valve hole 186, ports 186a-d, oil passage 188, oil passage 189, oil passage 190, valve hole 192, ports 192a-g, spool 194, lands 194a-e, negative pressure diaphragm 198, orifice 199, orifice 202 , Orifice 203, valve hole 204, port 204a ~
e, spool 206, lands 206a-b, spring 208, oil passage 209, filter 211, orifice 216, port 222, solenoid 224, plunger 224a, spring 225, valve hole 23
0, ports 230a-e, spool 232, lands 232a-b, spring 234, oil passage 235, orifice 236, valve hole 240, ports 240a-h, spool 242, lands 242a-e, oil passage 243,
Oil passage 245, orifice 246, orifice 247, orifice 2
48, orifice 249, choke type throttle valve 250, relief valve 251, choke type throttle valve 252, pressure holding valve 253, oil passage 254,
Cooler 256, cooler pressure holding valve 258, orifice 259, changeover detection switch 278.

FIG. 4 shows a shift control device 300 that controls the operation of the step motor 110 and the solenoid 224. The shift control device 300 is
Input interface 311, reference pulse generator 312, CPU
(Central processing unit) 313, ROM (Read only memory) 31
4. Has RAM (random access memory) 315 and output interface 316, which are address bus 319
And data bus 320. This shift control device 300 includes an engine speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, a shift position switch 304, a turbine speed sensor 305, an engine cooling water temperature sensor 306, a brake sensor 307 and a changeover detection switch 298. Signal of direct or waveform shaper 3
Input through 08, 309 and 322, and AD converter 310,
On the other hand, through the amplifier 317 and lines 317a-d
A signal is output to 10 and a signal is also output to the solenoid 224, but detailed description thereof will be omitted.
Incidentally, the structure of the portion whose description is omitted is described in the above-mentioned Japanese Patent Application No. 59-226706.

5 to 7 show the contents of control performed by the shift control device 300. Of these, the complete engagement control of the clutch by controlling the solenoid 224 and the fluid coupling 12
The lock-up control of the above-mentioned Japanese Patent Application No. 59-2267
The description is omitted because it is the same as that described in No. 06.

A step motor control routine is shown in FIGS. In step 602, the actual vehicle speed V is a predetermined small value V _0.
If it is larger than the above, the routine proceeds to step 624, where it is judged whether or not the shift position is in the D range, and if it is in the D range, the D range shift pattern is searched (step 626). If it is determined in step 639 that the L range is set, the L range shift pattern is searched (step
628), if it is determined to be in the R range, the R range shift pattern is searched (at 640). Steps 626, 62
After 8 and 640, proceed to step 902, and brake sensor 3
It is judged whether or not the signal from 07 indicates that the brake is in use. If the brake is used, the B flag is set (step 904). If the brake is not used, step 906 is directly executed. Go to. In step 906, whether the throttle opening TH is smaller than a predetermined small value TH ₀ (i.e., whether or accelerator pedal depression amount is substantially zero) to determine, in fact in the case of TH <TH ₀ It is determined whether the vehicle speed V of the vehicle is greater than a predetermined value V ₁ (90
8) If V> V ₁ , set T ₀ as the timer value T. The value of V ₁ is 10
The vehicle speed at which the fuel cut device 11 of FIG. If TH> TH _{0 in} step 906 or V ≦ V _{1 in} step 908, the process proceeds to step 912, it is determined whether the timer value T is 0, and if T = 0, the process proceeds to step 916 as it is. If T is not 0, 1 is subtracted from the timer value T and set as a new timer value T (step 914).
Proceed to step 916. In step 916, it is determined whether T is 0, and when T = 0, the B flag is settled (same as above).
918), the process proceeds to step 920. If T = 0 is not satisfied, the process directly proceeds to step 920. In step 920, it is determined whether or not the B flag is set. If it is not set, the process proceeds to step 630 as it is, and if it is set, the value of α stored in step 922 is searched. R
The OM 314 stores a value of α that decreases as the value of the vehicle speed V increases. After the search for α in step 922, the process proceeds to step 924, and α is added to the value of the target pulse number P _D searched in step 626, 628, or 640, and this is newly set as the target pulse number. Then, it proceeds to step 630. In step 630, the target pulse number P _D is compared with the actual pulse number P _A, and then a signal for driving the step motor is output so that the actual pulse number P _A matches the target pulse number P _D. To be done.

Eventually, the following operation will be performed by the control of steps 902 → 924. When the brake is used and the throttle opening is 0, that is, when the operating condition requires engine braking, the fuel cut device 11
When the fuel supply is stopped (V <V ₁ ), a predetermined timer value T ₀ is set. In this state, step 920 → 922
Since the process proceeds to → 924, the predetermined value α is added to the target pulse number P _D , and the target gear ratio becomes larger than the gear ratio searched in step 626, 628 or 640. That is, the gear ratio becomes a gear ratio larger than the minimum gear ratio by a predetermined value, and the engine braking effect can be obtained. Since the value of α is set to a value that decreases in accordance with the vehicle speed, the increase in the gear ratio becomes large at low vehicle speeds, and a sufficient engine braking effect can be obtained, and at high vehicle speeds. In this case, since the increase in the gear ratio is small, it is possible to prevent an excessive gear shift shock. When the accelerator pedal is depressed for re-acceleration from the running state of the engine braking state as described above (or the vehicle speed decreases to V ₁ even if the throttle opening remains 0), the routine proceeds to step 914. The value T is gradually decreased. Timer value T is 0
Since the set state of the B flag is held until the time becomes, that is, until the set T ₀ time elapses,
Control through 922 and 924 is performed, and control for increasing the gear ratio by α continues. After the lapse of T ₀ time, the B flag is cleared in step 918, and the addition of α is stopped. That is, the control for increasing the gear ratio by α when the throttle opening is increased (or when the vehicle speed decreases to V ₁ ) is not immediately released, but is released after the time T _{0 has} elapsed. On the other hand, the fuel cut device 11 of the engine 10 immediately starts the supply of fuel when the throttle opening degree increases or when the vehicle speed decreases to V ₁ . Therefore, the shift of the continuously variable transmission is performed after T ₀ time has elapsed since the fuel supply to the engine 10 was restarted. This prevents the engine torque fluctuation and the continuously variable transmission from shifting at the same time when the engine brake state is released, and prevents a large shock from occurring.

Although the present embodiment has been described with respect to the case where the present invention is applied to a continuously variable transmission, the fuel supply to the engine is restarted even in the case of a stepped automatic transmission that is automatically downshifted during coasting. A similar effect can be obtained by providing a time difference between the shift of the automatic transmission and the shift of the automatic transmission. Also, in this embodiment, the operation of the continuously variable transmission is delayed from the switching of the fuel cut device so that the two operations are not synchronized, but the switching of the fuel cut device is delayed by the same method as in this embodiment. It is also possible to obtain the same effect by restarting the fuel supply to the engine after the shift is performed.

(G) Effect of the Invention As described above, according to the present invention, when the restart of fuel supply of the fuel cut mechanism and the release of the downshift state of the transmission are simultaneously instructed, restart of fuel supply and downshift are performed. Since the time difference setting means for setting a predetermined time difference between the state release and the state release is provided, it is possible to prevent the torque fluctuation of the engine and the gear shift of the transmission from occurring at the same time, and to reduce the shock. it can. Further, by appropriately setting the amount of change in the gear ratio by the downshift means according to the vehicle speed, the engine braking effect and shock can be made suitable.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between components of the present invention, FIG. 2 is a sectional view of a continuously variable transmission, FIG. 3 is a diagram showing a hydraulic control device,
FIG. 4 is a view showing a shift control device, and FIGS. 5, 6 and 7 are views showing a control routine.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihisa Anbo, Niban Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Masaki Nakano, Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan

Claims (2)

[Claims] Claim: What is claimed is: 1. An engine equipped with a fuel cut device for stopping the supply of fuel in a predetermined operating state is automatically downshifted when the throttle is fully closed and the brake is applied. In a control device of an engine transmission in the case of combining a transmission having a downshift means for shifting to, the fuel cut device is in a state where fuel supply to the engine is stopped and the downshift means downshifts the transmission. When the restart of fuel supply and the release of the shift state to the downshift side are simultaneously instructed in the state where the shift is made to the side, a predetermined period is provided between the restart of the fuel supply and the release of the shift state to the downshift side. A control device for a transmission and a fuel cut device, comprising a time difference setting means for setting a time difference. 2. A control device for a transmission and a fuel cut device according to claim 1, wherein the downshift means determines the downshift amount of the transmission according to the vehicle speed.