JPS59213527A - Controller of automatic clutch - Google Patents

Abstract

PURPOSE:To prevent an engine from unexpected hault or so by changing over a clutch into the start control condition where the engaging force thereof is enhanced according to rpm. of the engine if the rpm. is reduced below a specified value with the clutch under control for full engagement. CONSTITUTION:An operation control means for an automatic clucth which is interposed between the output shaft of an engine and the input shaft of a transmission gear puts the clutch into both the start control condition where the engaging force thereof is enhanced according to rpm. of the engine and the control condition where the clutch is fully engaged. The means is provided with a controlled clutch condition changeover means which receives the signal of engine rpm. When with the clutch under control for full engagement, the engine rpm. reaches a value approximately equal to the minimum speed at which the engine is allowed to run or below the value of a specified speed, the changeover means controls the clutch to make changeover into the start control condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to an automatic clutch control device.

(b) Prior art As a conventional automatic clutch control device, the
There is one described in No. 26021.

This automatic crank/crunch control device controls the engine speed (
That is, the rotational speed of the driving member side of the clutch and the rotational speed of the non-driving member side of the clutch are detected, and when both rotational speeds are approximately equal, a clutch complete engagement signal is output to completely engage the clutch. That's how it is. When the vehicle decelerates to a stop, the clutch is completely released when the engine reaches idling speed to prevent the engine from stopping. After the latch is completely released in this way, the degree of engagement of the clutch is controlled again in accordance with the engine speed.

However, as mentioned above, if the fully engaged clutch is completely released when the engine reaches idling speed (if the gear ratio is a constant value, the vehicle speed will also be below a predetermined value), the operating state Depending on the situation, the timing of releasing the clutch may be too early or too late.
If it is too early, the engine will run dry, and if it is too late, a shock will occur due to clutch release, the engine will stop, etc.

(C) Purpose of the Invention The present invention provides that when the fully engaged state of the clutch is released,
The object of the present invention is to provide an automatic clutch control device that does not cause engine revving, shock due to clutch disengagement, engine stop, etc.

(D) Structure of the Invention The present invention solves the above problem by switching to a start control state (instead of completely disengaging the clutch) when the engine speed drops below a predetermined speed after the clutch is fully engaged. do. That is, the automatic clutch control device according to the invention includes a clutch control state switching means that switches the fully engaged control state to the start control state when the engine rotational speed becomes less than a predetermined value while the automatic clutch is in the fully engaged control state. (e) Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 7 of the accompanying drawings.

(First embodiment) Fig. 1 shows a forward clutch 4 which is a hydraulic automatic clutch.
and a power transmission mechanism of a continuously variable transmission equipped with a reverse clutch 24. This continuously variable transmission transmits the rotation of the input shaft 2 to the output shafts 76 and 78 via the drive pulley 6, 50, driven pulley 51, etc. by engaging the forward clutch 4 or the reverse clutch 24. can do. This continuously variable transmission includes an input shaft 2, a forward clutch 4, a drive pulley 6, a drive shaft 8, an oil pump 10, a drive gear 12,
Driven gear 14, rotary groove 16, oil sump 18, pitot tube 20, subshaft 22, reverse clutch 24, gear 26.2
8.30.32 and 34, piston chambers 36 and 38, fixed conical plate 40, drive pulley cylinder chamber 42, movable conical plate 44, rotating groove 46, oil reservoir 47, pitot tube 48
, ■ Belt 50, driven pulley 51, driven shaft 52, fixed conical plate 54, driven pulley cylinder chamber 56, spring 5
7. Movable conical plate 58, gear 60, ring gear 62, differential case 64, pinion gears 66 and 68, differential device 7
0, side gears 72 and 74, and output shafts 76 and 78
, is composed of.

Detailed explanation of these will be omitted. The structure of the parts whose explanations are omitted is described in Japanese Patent Application No. 184627-1988 "Control Device for Hydraulic Automatic Clutch" filed by the present applicant (filed on October 22, 1982). .

FIG. 2 shows a control device for a continuously variable transmission including a control device for a hydraulic automatic clutch according to the present invention. As shown in FIG. 2, the control device for this continuously variable transmission includes an oil pump 10.
, line pressure regulating valve 102, manual valve 104, speed change control valve 106, clutch full engagement control valve 108, speed change motor (step motor) 110, speed change operation mechanism 112, throttle valve 114, starting valve 116, start adjustment valve 118 , a maximum gear ratio holding valve 120, an eight-switch inhibitor valve 122, a lubricating valve 124, a tank 130, an electronic control device 300, etc., which are connected to each other as shown in the figure, and a forward clutch. 4, the piston chamber 38 of the reverse clutch 24, the driving pulley cylinder chamber 42, the driven pulley cylinder chamber 56, and the pitot tubes 20 and 48. Hereinafter, clutch complete engagement control valve '1o8, which is directly related to the present invention,
The starting valve 116 and the start adjustment valve 118 will be explained in detail, and detailed explanations of other valves and the like will be omitted. Incidentally, the structure of the parts whose explanation is omitted is described in the above-mentioned Japanese Patent Application No. 184627/1983.

The clutch complete wIMM control valve 1.08 has its valve body integrally formed with the rod 182 of the speed change operation mechanism 112.

In other words, the clutch is fully engaged and the control valve 108 is at port 1.
Valve hole 186 having 86a and 186b and lot 18
It consists of two lands 182a and 182b. The port 186a communicates with the aforementioned pitot tube 48 through an oil passage 188. That is, a signal hydraulic pressure corresponding to the rotational speed of the drive pulley 6 is supplied to the port 186a. Port 186b communicates with port 204e of starting valve 116 via oil passage 190.

Normally po 1-186 a and 186b are land 182
a and 182b, but the rod 18
2 is the position corresponding to the maximum gear ratio (shift reference switch 2
Port 186a is closed and port 186b is drained only when the port 186a is moved beyond the on position (98) into the overstroke region. That is,
The clutch complete engagement control valve 108 normally operates on the drive pulley 6.
rotation speed signal oil pressure of starting valve 116)
204e, and has a function of stopping the supply of the signal hydraulic pressure when the load 2 load 182 exceeds the maximum gear ratio position and moves into the overstroke region.

The starting valve 116 has ports 204a and 204b.
, 204c, 204d and 204e.
and lands 206a, 206b, 206c and 206d
The spool 2o6 includes a spool 2o6 (note that the left side portion of the land 206a in the figure is tapered in diameter) and a spring 208 that pushes the spool 206 to the right in the figure. The port 204a is connected to the oil passage 162, which is a throttle pressure circuit, through an orifice 210.
It communicates with 40. The port 204b is drained via an oil passage 200 (this oil passage communicates between the oil pump 10 and the strainer 131), which is a drain circuit. Port 2゜4c (O,,, 2□2' to 'hL'
, 1□-1. □Ka, 1. □Connected to 18. The port 204d communicates with the pitot tube 2o described above through an oil passage 214.

That is, a signal hydraulic pressure corresponding to the rotational speed of the input shaft 2 (that is, an engine rotational speed signal hydraulic pressure) is supplied to the port 204d. As described above, the port 204e communicates with the port 186,b of the clutch full engagement control valve 108 through the oil passage 190. Orifices 216, 218, and 220 are provided at the inlets of ports 204c, 204d, and 204e, respectively. The starting valve 116 has a function of discharging the oil in the port 204a to the port 204b according to the position of the spool 206, thereby setting the oil pressure (starting pressure) in the oil passage 140 to a pressure lower than the slow/torre pressure.

That is, when the spool 206 is located toward the left side in the figure, the gap from the port 204a to the port 204b is small, so the oil pressure at the port 204a is high; conversely, when the spool 206 moves to the right side in the figure, the oil pressure at the port 204a is high. 204 a
The gap between the port 204b and the port 204b increases, the amount of oil leaking increases, and the oil pressure at the port 204a decreases. Note that the oil passage 162, which is the throttle pressure circuit, and the oil passage 140, which is the start pressure circuit, are connected through the orifice 210, so even if the oil pressure in the oil passage 140 becomes low, the oil passage 162
throttle pressure is virtually unaffected. , the position of the spool 206 depends on the force of the spring 208 and the land 20
The rightward force of force due to the hydraulic pressure (start adjustment pressure) acting on the area difference between 6b and 206a and the land 206c
The hydraulic pressure (engine rotation speed signal hydraulic pressure) of port 204d that acts on the area difference between 206a and 206a
It is determined by the balance between the leftward force and the force caused by the oil pressure of the port 204e (driving pulley rotation speed signal oil pressure) that acts on 6d. That is, the higher the start adjustment pressure in the oil passage 212 slid by the start adjustment valve 118 (described later), the lower the start pressure in the oil passage 140, and the higher the engine rotation speed signal oil pressure and the drive cooler rotation speed signal oil pressure, the lower the start pressure. It gets expensive. At the time of starting, the rod 182 of the clutch complete engagement control valve 108 is moved to the far left and the oil passage 190 is drained, so the drive pulley rotation speed hydraulic signal is not applied to the port 204e of the starting valve 116. I haven't. Therefore, the start pressure is controlled by the start adjustment pressure and the engine speed signal oil pressure, and gradually increases as the engine speed increases. This start pressure is supplied to the forward clutch 4 (or the reverse clutch 24), which is gradually engaged to enable a smooth start.

When the start progresses to a certain extent, the clutch full engagement control valve 108 is switched by the action of the step motor 11O, and the drive pulley rotation speed signal oil pressure is supplied to the port I/204e via the oil passage 190, and the start pressure rises rapidly. .

As a result, the forward clutch 4 (or the reverse clutch 2
4) is securely fastened and there is no slippage. In addition,
Starting 54-z l 16 is port 204a
The forward clutch 4 and the reverse clutch 24 adjust the throttle pressure according to the engine output torque that is combined with the forward clutch 4 and the reverse clutch 24.
Therefore, unnecessarily high hydraulic pressure does not act on the forward clutch 4 and the reverse clutch 24. This is suitable for the durability performance of the forward clutch 4 and the reverse clutch 24.

The start adjustment valve 118 is connected to the oil port 1-2 of the oil passage 212.
22 (This port 222 is connected to the oil passage 20 which is a drain circuit.
The force motor 224 is configured by a force motor 224 that can adjust the amount of discharge to (in communication with 0) by means of a plunger 224a. Low-pressure oil is supplied to the oil passage 212 from an oil passage 164, which is a lubricating oil passage, through an orifice 226. Since the force motor 224 discharges oil from the oil passage 212 in inverse proportion to the amount of energization, the oil pressure (start adjustment pressure) of the oil passage 212 is controlled by the amount of energization.

The amount of current applied to the force smoke 224 is controlled by the speed change control device 300. When the vehicle is in an idling state where the vehicle is stopped, the start pressure (hydraulic pressure regulated by the starting valve 116) is applied to the forward clutch 4 by the start adjustment pressure obtained by the start adjustment valve 118.
Alternatively, the reverse clutch 24 is controlled to be in a state immediately before starting engagement. Since this start pressure is always supplied to the forward clutch 4 or reverse clutch 24 before starting, the forward clutch 4 or reverse clutch 24 starts to engage immediately as the engine speed increases, and the engine speed increases. There is no possibility of engine racing, and even if the engine's idling speed is higher than normal, there will be no false start.

Next, the step motor 110 and the force smoke 224
The transmission control device 300 that controls the operation of the transmission control device 300 will be explained.

As shown in FIG. 3, the transmission control device 300 includes an engine rotation speed sensor 301. "FM sensor 302, throttle opening sensor (or intake %' negative pressure sensor)
303, a shift position switch 304, a shift reference switch 298, an engine coolant temperature sensor 306, a brake sensor 307, and a star pressure detection pressure sensor 321. Electric signals are input thereto. The engine rotation speed sensor 301 detects the engine rotation speed from the ignition pulse of the engine, and the vehicle speed sensor 30
2 detects the vehicle speed from the rotation of the output shaft of the continuously variable transmission. Throttle opening sensor (or intake pipe negative pressure sensor) 30
3 detects the throttle opening of the engine as a voltage signal (in the case of an intake pipe negative pressure sensor, the intake pipe negative pressure is detected as a voltage signal). The shift position switch 304 detects which position of the above-mentioned manual valve 104 is located among P, R, N, D, and L. Shift reference switch 298
is a switch that is turned on when the rod 18.2 of the aforementioned speed change operation mechanism 112 reaches the position where the speed change ratio is the largest (note that the rod 182 is moved further when the speed change reference switch 298 is turned on). (that is, overstroke is possible). The signal when the speed change reference switch 298 is turned on acts as a maximum speed change ratio command signal. Engine coolant temperature sensor 306 generates a signal when the engine coolant temperature is below a certain value. Brake sensor 307 detects whether the vehicle's brakes are being used. The start pressure detection pressure sensor 321 converts the start pressure of the oil passage 140 described above into an electrical signal. Signals from the engine speed sensor 301 and vehicle speed sensor 302 are sent to the input interface 311 through waveform shapers 308 and 309, respectively.
Further, a voltage signal from the throttle opening sensor (or intake pipe negative pressure sensor) 303 is converted into a digital signal by an AD converter 310 and sent to an input interface 311 . The speed change control device 300 includes an input interface 311, a CPU (central processing unit) 313, and a base '11.
1 Upulse generator 312, ROM (read only memory) 314, RAM (random access memory) 315
, and output interfaces 316, which are communicated by an address bus 319 and a data bus 320. The reference pulse generator 312 is
Generates a reference pulse that activates 13. ROM31
4 includes a step motor 110 and a force smoke 22.
4 and stores the data necessary for the control.

The RAM 315 temporarily stores information from each sensor and switch, parameters necessary for control, and the like. The output signals from the speed change control device 300 are sent to amplifiers 31, respectively.
7 and step motor 110 via current controller 318
and is output to the force smoke 224.

Next, the control of force smoke 224 performed by this transmission control device 300 will be explained. A force smoke control routine 500 is shown in FIG. The force smoke control routine 500 has a function of adjusting the start pressure via the start adjustment valve 118 and the starting valve 116 when the engine is idling, and bringing the forward clutch 4 (or the reverse clutch 24) to a state immediately before starting engagement. have This force smoke control routine 500 is executed at regular intervals (that is, the following routine is repeatedly executed within a short period of time). First, the throttle opening TH is read from the throttle opening sensor 303 (step 501), and the vehicle speed V is read from the vehicle speed sensor 302.
(503), and then step 5
05, it is determined whether the vehicle speed is less than a predetermined small value Vo, and if it is less than the predetermined value vO, the throttle opening TH is set to a predetermined small value T in step 507.
If it is less than a predetermined value THo (that is, the vehicle is stopped and the engine is in an idling state), the process advances to step 509 and the start pressure Ps is read from the start pressure detection pressure sensor 321. In addition, in steps 505 and 507, v>vO or TH>THo
If it is determined that this is the case, the routine proceeds to step 527 and outputs the same force motor current signal as in the previous routine, that is, the current signal immediately before V>Vo or TH>THo. After reading the start pressure Ps in step 509, the process proceeds to step 511, where it is determined whether the start pressure Ps is larger than the target pre-fastening start pressure upper limit value Psu. If Ps>PSU, a minute value Δ■ is added to the force smoke current signal ■ of the previous routine to obtain a new current signal value (step 513). Next, it is determined whether the current signal is less than or equal to the maximum allowable current signal (step 545), and if I≦Io, the process continues to step 5.
If I>Io, then I=Io (step 517), and the process proceeds to step 527, where the force smoke current signal I is output. In step 511, Ps≦
In the case of Psu, it is determined whether the start pressure is smaller than the target start pressure lower limit value PSL before the start of engagement (step 519), and if Ps≧PSL (7) (when combined with the judgment in step 511, Ps, -≦Ps≦Psu becomes.

That is, the start pressure Ps is between the upper and lower limits of the target start pressure before starting cotton tying. ), the program proceeds to step 527 and outputs the current signal of the previous routine as is. If PS<PSL in step 519, a small value ΔI is generated from the force smoke current signal I, and this is used as a new current signal (step 521). Next, in order to prevent the current signal ■ from becoming negative, it is determined whether ■≧O or not (step 523). If I≧0, the process directly proceeds to step 527, and if I<O, the process proceeds to step 525.
In step 527, I=O is set, and the current signal signal is output. After all, through the above series of steps, if the start pressure Ps is larger than the target upper limit value before starting engagement, the force smoke current signal I is increased and the start pressure Ps is increased.
If the start pressure Ps is smaller than the lower limit value of the start pressure before the start of the target engagement, control is performed to decrease the forced smoke current and increase the start pressure, and the start pressure Ps is set to the start pressure before the start of the target engagement. Above the front start pressure,
maintained between the lower limits.

The target start pressure before the start of engagement is the hydraulic pressure just before the forward clutch 4 (or reverse clutch 24) starts to engage (in other words, the hydraulic pressure at which engagement starts when the forward clutch 4 (or reverse clutch 24) is slightly higher than this, or the hydraulic pressure that is slightly engaged to the extent that the vehicle does not start) (hydraulic pressure). Therefore, when the engine rotation speed increases from this state, the starting pressure PS becomes the oil pressure obtained by adding the oil pressure corresponding to the engine rotation speed to the target start pressure before engagement due to the action of the starting valve 116, and the forward clutch 4 (or reverse The clutch 24) is engaged and the vehicle starts moving. This makes it possible to obtain a stable starting operation without any problems such as engine idling or erroneous starting, regardless of fluctuations in the idle speed of the engine. This is because the engine's idle speed! ±When using the choke, when using data, when the engine malfunctions, etc., will not match the normal setting value, but regardless of the idle speed, the start pressure Ps is controlled to always be the target start pressure before the start of engagement due to the above action. This is because it will be done.

Next, the complete engagement control routine 600 will be explained.

The complete fastening control routine 600 is shown in FIGS. 5(A) and (B).
Shown below. The complete engagement control routine 600 is executed following step 527 of the force motor control routine 5°O described above. That is, the process advances from step 527 to step 801, and the shift reference switch 298 of this routine is activated.
The data of the shift reference switch 298 of the previous routine is read in step 602, and then in step 6.3 it is determined whether the shift reference switch 298 was on in the previous routine. .

If the shift reference switch 298 was off in the previous routine, the shift reference switch 298 of the current routine.

It is determined whether the switch 298 is on (step 604).
, if it is off, the process proceeds to step 650a, and if it is on, the complete fastening pulse number data M is kept constant.
(step 605), and the process proceeds to step 650a. Furthermore, if the shift reference switch 298 of the previous routine is on in step 603, it is determined whether the shift reference switch 298 of the current routine is on (
Step 606), if it is on, proceed to step 607a, and in step 607a, the input/output rotation ratio i (=A 1 - NE /■) is determined from the engine rotation speed NE and the vehicle speed V.
is first issued (Ai is a predetermined constant). Input/output rotation ratio i
is the apparent gear ratio that also includes clutch and crunch slippage. 4. The number of pulses Mo mentioned above is based on the speed change operation mechanism 112.
immediately before the rod 182 moves to the left in FIG. 2 and enters the overstroke region, that is, the shift reference switch 2
This corresponds to the position of the step motor 110 when the motor 98 is turned on. In this position, the clutch complete engagement control valve l
.

The drive pulley rotation speed signal oil pressure is guided from 8 to the starting valve 116. The starting valve 116 increases the starting pressure based on this drive pulley rotational speed signal oil pressure and supplies it to the clutch. Therefore, the clutch is fully engaged.

After calculating the input/output rotation ratio i in step 607a, in step 607b, it is determined whether the input/output rotation ratio i is approximately equal to the gear ratio ico at the time of starting when the clutch is not slipping, that is, the i mark - Ki≦i≦f LO+K
i (Ki is a small constant).

If the input/output rotation ratio i is outside the above range, step 6071
607j), the gear ratio timer Ti is set to O, and the complete engagement flag F is determined (607j). If F = 0 (instruction for complete clutch engagement has not been issued), the clutch is still slipping. Since it is in the starting state, step 631
Proceed to the next step. In step 631, it is determined whether the complete engagement pulse number data M is O, and if it is MsO, it is determined whether the timer value T is 0 or negative (635), and the timer value T is positive. In this case, the predetermined subtraction value ΔT is subtracted (637 as i T), and the same step motor drive signal as in the previous routine is output.
47), return. By repeating this, the subtraction value ΔT is repeatedly subtracted from the timer value T, so that after a certain period of time, the timer value T becomes O or negative. When the timer value T becomes O or negative, move the step motor drive signal one step in the downshift direction (641)
. Also, the timer value T should be set to a predetermined positive value T1.
43), reset the pulse liM to the current number of step motor pulses M minus 1 (645),
It outputs a step motor drive signal that has been shifted one step in the downshift direction (647) and returns. This causes the step motor 110 to move 1 in the downshift direction.
Rotated by the unit. By repeating the above routine, the value of M gradually becomes smaller, and when M=O is reached, the process proceeds from step 631 to step 650a. In addition, the number of pulses M
=0 corresponds to the position of the step motor 110 at the end of the overstroke region where the rod 182'' of the speed change operation mechanism 112 has moved farthest to the left in FIG. At this position, the drive pulley rotational speed signal hydraulic pressure that has been led to the starting valve 116 by the clutch full engagement control valve 108 interlocked with the step motor 110 is drained.

By doing so, the starting pressure Ps created by the starting valve 116 becomes a hydraulic pressure corresponding to the engine rotational speed NE (that is, the complete engagement is released).

If the complete engagement flag F=1 in step 607j described above (a state in which a clutch complete engagement command has been issued), the process proceeds to step 613 to be described later, and the clutch fully engaged state is maintained.

Further, in step 607b described above, when the calculated input/output rotation ratio i is approximately equal to the gear ratio ico at the time of starting, the process proceeds to step 607C, and the gear ratio timer Ti is set to 0.
If it is Ti-0, the calculated input/output rotation ratio i at that time is read and set as 1p=i (607d). Also, if Ti″-, O, ip
is not modified and the process proceeds to step 607e. That is, ip
represents the calculated input/output rotation ratio when the gear ratio timer Ti is 0. In step 607e, the calculated input/output rotation ratio i and ip are compared. Input/output rotation ratio i
If it is in the vicinity of IP, proceed to step 607f;
1 is added to the gear ratio timer Ti. Next, in step 607g, it is determined whether the gear ratio timer Ti has reached the predetermined time AT, and if it has reached the A1 time (that is, the calculated input/output rotation ratio l is equal to the gear ratio i at the time of starting).
If the state near LO is maintained for the AT waiting time (607h), F is set to 1 (607h), and then the process proceeds to step 613 and below, where complete engagement control is performed.

Note that in step 607e described above, the input/output rotation ratio i
If it is not near ip, the process returns to step 6071 and the gear ratio timer Ti is set to O again. Also, step 6
If the predetermined time AT has not been reached at step 07g, the process returns to step 607j and subsequent steps.

After setting the complete engagement flag F to 1 in step 607h, the process proceeds to step 613, where it is determined whether the complete engagement pulse number data M is MO, and M''=.
In the case of MO, the process advances to step 615. Step 61
In step 5, it is determined whether the timer value T is negative or O, and if the timer value T is positive, a predetermined subtraction value ΔT is subtracted from the timer value T and this is set as a new timer value. (617), outputs the same step motor drive signal as in the previous routine (647), and returns. This step 617 is repeatedly executed until the timer value T becomes 0 or negative. When the timer value T becomes O or negative, that is, when a certain period of time has elapsed, the step motor 1
10 drive signal is moved one step in the upshift direction, (
619), the timer value T should be set to a predetermined positive value T1 (621), and the number of pulses M should be reset to the current number of pulses M of the step motor plus 1 (623).
), outputs a step motor drive signal that has been shifted one step in the upshift direction (647), and returns. This causes the step motor 110 to move 1 in the upshift direction.
Rotated by the unit.

By repeating the above routine, the value of M increases, and M
When reaching = M o, step 613 to step 6
Proceed to 50a. Note that even if the shift reference switch 298 of the current routine is off in step 606, the process proceeds to step 650a.

In step 650a, the engine rotation speed NE is compared with the control switching engine rotation speed Nc (i.e., a speed approximately equal to or lower than the lowest engine rotation speed at which the vehicle can travel without generating vibrations in the fully engaged state of the flange). However, if NE≦Nc, the complete engagement flag F=
0 (step 650f), and then the process proceeds to step 631 to release the fully engaged state and return to the start control state. This prevents the engine from racing, stopping the engine, causing shock, etc. Step 6
If NE>NC in step 50a, it is determined in step 650d whether the engine stop dangerous vehicle speed is less than vB, and V
In the case of ≦VB, it is determined in step 650g whether the throttle opening is less than or equal to the opening THo close to fully closed, and if TH≦THo, it is determined in step 650e whether or not the breech is being used. If so, the fully engaged state is switched to the start control state at 650 f or less.

In cases other than the above, that is, step 650d
If V o C7), step 650 gTeTH>T
If the result is Ho, or if the brake is not used in step 650e, the process advances to step 651. In step 651, it is determined whether the complete engagement flag F is 1, and F=
If it is 1, it is determined whether the number M of pulses for complete engagement is Mo (653). If it is M Hong MO, return, M
If =Mo, the routine advances to a step motor control routine 700 that controls the gear ratio. That is, the step motor control routine 700 is executed only when the clutch is fully engaged and M = Mo.
.

It is. Note that the step motor control routine 700 is described in Japanese Patent Application No. 1984-184, which was previously proposed by the applicant of the present application.
Since it is clear from No. 627, the explanation will be omitted.

The operation of the complete engagement control routine 600 will be summarized and explained by case as follows.

First, if the shift reference switch 298 was off in the previous routine and turned on in the current routine (step 603
→604→6.05→650a). Set the number of pulses M to Mo. This is because the step motor 110 rotates from the small gear ratio side to the large gear ratio side and reaches the reference position where the gear change reference switch 298 is switched from on to off, so the number of pulses at this reference position is set to Mo. At this time, the starting valve 116 is in a state where the clutch is fully engaged.

Next, if the shift reference switch 298 is on in both the previous routine and the current routine (steps 603+60
6-607a → 607b + 6071 → 607j → 63
1 or 613). In this case, the vehicle is in a starting state or in a state in which the maximum gear ratio is commanded. The input/output rotation ratio is calculated from the engine rotation speed and the vehicle speed, and if the calculated input/output rotation ratio is not approximately equal to the maximum gear ratio, it is determined that the condition is in the middle of starting or kickdown, and the gear is changed. The ratio timer Ti is set to 0, and a fully engaged release state (start control state) or a fully engaged state is maintained depending on the state of the fully engaged flag F.

Next, similarly, if the speed change reference switch 298 is on in both the previous routine and the current routine, but the calculated input/output rotation ratio is approximately equal to the maximum speed change ratio (step 603→
606→607a→607b-607cm+607d+
607e-607f+607g→607j). That is, if the calculated input/output rotation ratio is approximately equal to the maximum gear ratio of the continuously variable transmission, the input/output rotation ratio ip when the gear ratio timer Ti=0 and the calculated input/output rotation ratio when this routine is reached are The input/output rotation ratio is compared for each routine, and if the input/output rotation ratio calculated during a predetermined number of routines is approximately equal to ip, it is determined that the clutch is already fully engaged, and the complete engagement flag F is set. is set to 1, and step 613
The following complete fastening control is performed.

The input/output rotation ratio and ip calculated in the above routine
If it is different from the above, it is determined that the gear is in a gear shifting state such as when starting or kicking down, and the gear ratio timer Ti is set to O, and the fully engaged disengaged state (start control state) or fully engaged state is maintained. (Step 607e→Step 6071→
Step 607j). In addition, if the calculated input/output rotation ratio does not remain equal to ip for a predetermined period of time,
The completely disengaged state (start control state) or fully engaged state is maintained without resetting the gear ratio timer Ti to O (step 60fg+step 607j).

If the process proceeds to step 650a (step 650a and subsequent steps). In the steps following step 650a, in any of the following cases, the fully engaged flag F is set to 0, the fully engaged state of the clutch is released, and the same control state as at the time of starting is returned. That is, there are two cases: when the engine rotational speed is lower than the control switching engine rotational speed Nc, and when the brake is used at a vehicle speed lower than the engine stop dangerous vehicle speed VB during idling. Therefore, in this case,
The clutch is affected by the hydraulic pressure that brings the clutch into a state immediately before engagement, or by adding the hydraulic pressure according to the engine rotation speed to this hydraulic pressure, which prevents the engine from racing and, on the contrary, prevents the engine from stalling or causing shocks, etc. Not at all. In cases other than the above, depending on the state of the complete engagement flag F, if F=0, the start is not completed and the control returns to the beginning. Further, if the complete engagement flag F = 1, it is determined whether the step motor 110 is at the reference position, that is, whether M = Mo, and if M is not equal to MO, the step motor 110 is The next step motor control routine 7 is operated until it becomes equal to MO.
Go to 00.

Note that in step 650e, it is determined whether or not the brake is used, but the deceleration of the vehicle may be detected and it may be determined whether the deceleration is greater than or equal to a predetermined value.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention. In this second embodiment, step 650a of the first embodiment shown in FIG. 5 is replaced with step 650b, and the rest is completely the same. That is, in step 650b, it is determined whether the vehicle speed is equal to or less than the control switching vehicle speed Vc, and if it is equal to or less than Vc, the process proceeds to step 650f or later, and the complete engagement control state is switched to the start control state. If the vehicle speed is equal to or higher than Vc, the process proceeds to step 650d, where the same control as described above is performed. The control switching vehicle speed Vc is a vehicle speed that is approximately equal to or lower than the vehicle speed when the vehicle is traveling at the lowest possible engine rotational speed and maximum gear ratio with the clutch fully engaged.

That is, if Vc is converted to engine speed using the maximum gear ratio, it becomes equivalent to Nc in the first embodiment, and in the end, it is the same as determining the control switching timing using engine speed. Become. Therefore, the same functions and effects as in the first embodiment can be obtained.

(v) As has been described in detail, the automatic clutch control device according to the present invention controls the operation of a vehicle automatic clutch provided between an engine and a transmission, as shown in FIG. In a control device for an automatic clutch, the control device has two control states: a start control state in which the clutch engagement force is increased according to the engine rotation speed, and a complete engagement control state in which the clutch is completely engaged. Since the clutch control state switching means is provided to switch from the fully engaged control state to the start control state when the engine rotational speed becomes less than a predetermined value while the engine is in the engaged control state, when deceleration occurs while the clutch is fully engaged, The clutch enters a start control state, which provides the effect of preventing the engine from racing, stopping the engine, causing shock, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a V-belt continuously variable transmission, FIG. 2 is a diagram showing the entire hydraulic control device, FIG. 3 is a diagram showing the speed change control device, and FIG. 4 is a diagram showing the force motor control routine. Fifth
Figures (A) and (B) are diagrams showing a complete fastening control routine,
FIG. 6 is a diagram showing a second embodiment of the present invention, and FIG. 7 is a diagram corresponding to claims. 106・Fist・speed change control valve, 108---Clutch complete engagement control valve, 110φ・speed change motor (step motor), 112・speed change operation mechanism, 116・starting valve, 118・race start Adjustment □Valve, 120...
・Maximum gear ratio holding valve, 224...Force motor, 2
98・φ・Shift reference switch, 300・・Shift control device, 301・・φ engine rotation speed sensor, 302・
・Medium vehicle speed sensor, 303yu・・Throttle opening sensor, 500・Φ・Force motor control routine, 600
...Complete fastening control routine.

Claims (1)

[Claims] 1. A control device for controlling the operation of a vehicle automatic clutch provided between an engine and a transmission, which controls a start control state and a start control state in which the clutch engagement force is increased according to the engine rotation speed. , in an automatic clutch control device that has two control states, a fully engaged control state in which the clutch is completely engaged, and a fully engaged control state in which the clutch is in the fully engaged control state, if the engine rotation speed falls below a predetermined value, the fully engaged control state is activated. 1. A control device for an automatic clutch, comprising a clutch control state switching means for switching the clutch control state to a start control state. 2. The automatic clutch control device according to claim 1, wherein the predetermined value of the engine rotational speed is approximately equal to or less than the minimum engine rotational speed at which the vehicle can travel with the clutch fully engaged. 3. Automatic clutch control according to claim 1 or 2, wherein the fact that the engine rotational speed has become below a predetermined value is determined by the fact that the vehicle speed has become below a predetermined value in the maximum gear ratio state of the transmission. Device.