JPS60143266A - Controller for lock-up of torque converter - Google Patents

Abstract

PURPOSE:To reliably prevent the occurrence of a lock-up shock, by a method wherein the decrease rate of a slip amount is changed according to the slip amount and the number of output revolutions of a torque converter. CONSTITUTION:A lock-up deciding means 5, which decides whether a power source 1 is in a condition in which lock-up through operation of a clutch is effected, and a slip amount detecting means 6, which detects the relative number of revolutions between input and output elements, are provided. Operation of the clutch is controlled by feedback so that the slip amount of a torque converter is gradually decreased to zero in a ratio responding to the relative number of revolutions between the input and output elements and the number of revolutions of the output element preveiling during instructon of lock-up. This enables the given decrease rate of the slip amount to be changed in response to a slip amount and the number of revolutions of the torque converter, prevents the occurrence of an answering lag of lock-up, and permits reliable prevention of the occurrence of lock-up shock.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a torque converter inserted into a power transmission system such as an automatic transmission for a vehicle, and particularly to a torque converter that can be locked up by appropriately reducing the relative rotation (slip) between its input and output elements to zero. This relates to a lock-up control device that aims to reduce shock when a torque converter locks up. 0Prior art A torque converter transfers power between its input and output elements via hydraulic oil, and has a torque increasing function and a torque fluctuation function. It has an absorption function, but on the other hand, relative rotation (slip) between input and output elements cannot be avoided, resulting in poor power transmission efficiency. Therefore, in situations where the torque increasing function and torque fluctuation absorbing function are not required, torque converters that can be directly connected and locked up to prevent relative rotation between input and output elements have already been put into practical use.

This type of torque converter generally includes an input element driven by a power source and an output element driven by hydraulic oil stirred by the input element, and the relative rotation between the input and output elements is reduced to zero by appropriate clutch operation. It is normal to configure the device so that it can be directly connected and lock-up is possible.

The above-mentioned clutch is normally deactivated when the lock-up pressure supplied to it is made equal to the internal pressure of the torque converter (converter pressure), and the torque converter is operated in a converter state where the input and output elements are not directly connected, eliminating the lock-up pressure. When the torque converter is activated by the converter pressure, it functions to operate the torque converter in a lock-up state where the input and output elements are directly connected.

By the way, if the lock-up pressure is rapidly eliminated, the operating speed of the clutch that responds to this will also be faster, and when the torque converter is locked up by the clutch operation, a shock will occur.For this reason, normally, the lock-up pressure is not eliminated. Although the lock-up pressure is gradually removed through the oriice, the problem is still not solved. In other words, at instant t1 in Fig. 15, the lock-up pressure is removed from the converter command When switching to the lock-up command, the lock-up pressure decreases from a value equivalent to the converter pressure as shown in Fig. 10, and finally reaches zero.During this period, the clutch is activated at instant t2 after 7 hours have passed when the lock-up pressure reaches the value. The connection begins, and at instant t8, the connection is almost completed, and the torque converter changes from the converter state to the lockup state.However, as described above, since the lockup pressure is eliminated through the orifice, the lockup pressure remains at that value. With characteristics uniquely determined by the opening area of the orifice, the G decreases in a quadratic curve as shown in FIG.
Here, it is assumed that the lock-up pressure decreasing speed is too fast and the torque waveform of the torque converter output shaft has a peak torque α when the clutch is engaged. Therefore, even if an orifice is provided as in the prior art, it has not been possible to sufficiently reduce the shock when the torque converter switches to the lock-up state.

Therefore, the applicant of the present application previously proposed in Japanese Patent Application No. 58-87601 that the clutch is feedback-controlled so that the relative rotation of the input/output elements at this point after the lock-up command is uniformly and gradually reduced at a constant ratio to zero. Although we have already proposed a lock-up control device, we have confirmed that this method does not always reduce lock-up shock.

Now, considering lock-up shock, this is because the rotation speed of the power source (engine) decreases to be the same as the output rotation speed of the torque converter during lock-up, and the rotational energy changes due to the decrease in the rotation speed of the power source during this period. It occurs due to. Therefore, if the torque converter slip amount just before lock-up is ΔN, the torque converter output rotational speed is N□, and the inertia of the power source is factor, then the magnitude of the rotational energy change ΔE can be calculated from the energy equation by ΔEocI((N, +ΔN) 2 N12
), and rearranging this formula, ΔE is expressed as the following formula: 0 ΔE, oc(ΔN2+2ΔN−N□)
1) Therefore, as mentioned above, the magnitude of the lock-up shock that depends on ΔE is determined by the torque converter slip amount ΔN just before lock-up and the torque converter output rotation speed N.
□The larger these are, the greater the lock-up shock will be.

However, the lock-up control device previously proposed by the applicant has a small torque converter output rotation speed (N□'
) and the case where it is large (N It was confirmed that the following problem occurs because the torque converter output rotational speed N is set to zero regardless of the torque converter output rotation speed N, and the same ratio ΔN/ΔT is used to reduce the slip amount ΔN to zero.

In other words, as is clear from equation (1) above, the lock-up shock is larger in the case of FIG. 13 than in the case of FIG. , if the ratio ΔN/ΔT is determined to be small, this will be too large, and the latter lock-up shock will become larger due to the large peak torque α2; , this is too small, and the lock-up control %' is too small to achieve a sufficient fuel efficiency improvement effect due to the lock-up control. Such a tendency becomes significant by -11 when the slip amount ΔN is different, although it is related to the lock-up shock in proportion to the two strokes as shown in equation (1) above.

In view of the points beyond the purpose of the invention, the ratio ΔN/ΔT is the rotational energy change ΔE of the power source that causes lock-up shock.
In other words, as is clear from Equation (1) above, it is possible to reliably reduce lock-up shock and eliminate the above-mentioned problem without impairing the fuel efficiency improvement effect by increasing the slip amount ΔN and torque increase. From this point of view, it is an object of the present invention to provide a lock-up control device that embodies this idea.

Structure of the Invention For this purpose, the lock-up control device of the present invention comprises an input element 2 driven by a power source 1 as shown in FIG.
The torque converter is equipped with an output element 8 driven by the hydraulic oil thus stirred, and can be directly connected and locked up between the input and output elements by appropriately operating the clutch 4 so that the relative rotation becomes zero. lock-up determining means 5 for determining whether or not the power source l is in an operating state in which lock-up should be performed by actuation of the clutch; slip amount detecting means 6 for detecting the rotational speed relative to the input/output element; Upon receiving a lock-up command from the lock-up determining means 5, the relative rotation speed is gradually reduced to zero at a ratio corresponding to the rotation speed from the slip amount detection means 6 and the rotation speed of the output element 3 at the time of the command. It is characterized by comprising a clutch control means 7 that performs feedback control on the operation of the clutch 4.

·Example Hereinafter, the present invention will be described in detail from Example G shown in the drawings.

FIG. 2 shows the device of the present invention together with a torque converter to be subjected to lock-up control. In the figure, 10 is an engine as a power source, 11 is its crankshaft, 12 is a flywheel, 18 is a torque converter, and 14 is a torque converter output. It is the axis. During operation of the engine 10, the crankshaft 11 rotates together with the flywheel 12, and the torque converter 18 is connected to the flywheel 12.

A pump impeller (input element) 18a which is drive-coupled to the crankshaft 11 and is constantly driven by the engine, and a turbine runner (output element) 1.3b opposed thereto;
The turbine runner t3b is drive-coupled to the output shafts 14, and the stator 13C is placed on a hollow fixed shaft 16 via a one-way clutch 15. The torque converter 18 is supplied with working fluid from the pump 17 to its internal converter chamber lad through a supply path 18, and this working fluid is sent to the reservoir 2 through a return path 19.
The temperature is returned to 0, and at the same time, it is cooled by a heat radiator 21 provided in the middle. Note that a pressure holding valve (not shown) is inserted into the return path 19, thereby maintaining the inside of the converter chamber iaa at a pressure (converter pressure) Po below a value. Thus, as described above, the pump impeller 18a driven by the engine stirs the internal working fluid, causes it to collide with the turbine runner 13b, and then flows through the stator 130, during which time the stator 1
The turbine runner 1.3b is rotated under a reaction force of 80 degrees while increasing the torque. The torque converter 13 in operation in such a converter state is an input/output element 13a.

The power of the engine 1o can be transmitted to the output shaft 14 while suppressing vibration and increasing torque while generating a slip (relative rotation) between the lsb and lsb.

The torque converter 13 is further provided with a clutch (lock-up clutch) 22 in order to implement a slip control type and a lock-up type that can limit and cancel the above-mentioned slip, and is drivingly coupled to the output shaft 14 via a torsional damper 23. At the same time, the lock-up chamber 24 is set to be movable in the axial direction on this axis. Clutch 22 responds to lock-up pressure P in lock-up chamber 24 and converter pressure P in converter L/u chamber 13d. The input/output element 13a moves to the left in the figure due to the differential pressure between the input and output elements 13a.

13b, the slip of the torque converter 13 can be limited and stopped.

The lock-up pressure "L/u" is adjusted by the slip control valve 25 as described below. For this purpose, the lock-up chamber 24 communicates the hollow hole of the shaft 14 and the circuit z6 with the bow 25a of the slip control valve z5. The valve 25 is separately provided with a boat 25b to which the converter pressure Po is guided by a circuit 27, and a drain boat 25c.
When 5d is in the neutral position shown in the figure, connect 25a to both ports 25
b.

When the spool 2sd moves to the left in the drawing, the boat 25a is connected to the boat 25b, and when the spool 25d moves to the right in the drawing, the boat 25a is connected to the boat 21MC.

The spool 25d has a converter pressure P that acts on the pressure receiving area difference of the spool lands in the chamber 25e.

The force exerted by the lock-up pressure "L/u" acting on the pressure-receiving area difference of the spool land in the chamber 25f, and the control pressure P acting on the left end surface of the spool in the chamber 25g.
In response to the force exerted by s, the control pressure P8 is generated by the control pressure generation circuit 28 and the solenoid valve 29 as follows.

That is, the reference pressure (for example, line pressure in the case of an automatic transmission) PL is supplied to the control pressure generation circuit 28 from one end 28a thereof,
This line pressure is passed through orifice 28C2zsd to circuit 2.
8 is drained from the other end 28b. By determining this drain amount by the duty-controlled electromagnetic valve 29, a control pressure Ps can be created between the orifice 28C928 (1), and this is guided to the chamber 25g by the circuit 30.

The solenoid valve 29 includes a plunger 29a and a slide/id 29b that moves the plunger 29a to the left in the figure when energized, and a solenoid z9b.
When the solenoid 29b is energized, the plunger 29a is pushed away by the drain working fluid from the drain opening end zsb to allow the above drain, and when the solenoid 29b is energized, the plunger 29a moves to the left to close the drain opening end 28b. shall be. Then, energizing (energizing) the solenoid valve solenoid 29b
is within the pulse width (ON time) of the pulse signal as shown in FIGS. 3(a) and 3(b) from the slip control computer 31 which also performs lock-up control of the torque converter, which is the object of the present invention. Duty control is performed so that the process is repeated. However, Fig. 3(a) (
t When the duty (%) is small as shown in FIG.
It is a constant value determined only by the difference in pressure receiving area. Duty (
As P) increases as shown in FIG. 8(b), the solenoid valve 27 closes the drain opening end 28b for a long time, so the control pressure P8 gradually increases as shown in FIG. 4, and finally the line The pressure PL & will be equal.

In FIG. 2, as the control pressure Ps increases, this control pressure causes the spool 25d to move to the right as shown in FIG. L/u decreases.

On the other hand, as the control pressure P8 decreases, the spool 25d is moved to the left as shown in FIG.
is gradually increased, and the lock-up pressure "L/u" increases. By the way, since the control pressure P8 increases as the duty (%) increases as shown in Fig. 4, the lock-up pressure P8 increases as shown in Fig. 6 L/u. As shown in the figure, the converter pressure P is kept equal to the converter pressure P in a region where the duty (%) is small, and decreases as the duty (%) increases, and finally changes to zero.

The slip control computer 31 receives a signal 5or1 related to the rotation speed of the shaft 14 (output/blade element 18b) from the torque converter output rotation speed sensor 34 and an engine throttle opening signal STH from the throttle opening sensor 35 at tag+v, and generates an electromagnetic signal. The duty control of the valve 29 is performed as described below. For this purpose, the computer 31 is a microcomputer as shown in FIG. It is composed of an interface circuit (Ilo) 88 and an A/D converter 39. This microcomputer receives the signals Sir and SOr from the sensors 33 and 34 after being waveform-shaped by the waveform shaping circuit 40, and also receives the signal STH from the sensor 35.
are converted into digital signals by the A/D converter 89 and inputted, and the control program shown in FIG. 8 is executed based on these human input signals to control the solenoid valve slide 29b via the amplifier 41.

FIG. 8 shows an interrupt routine, in which the following arithmetic processing is performed every time an interrupt signal is received from a timer (not shown) at regular time intervals ΔT in step 50, and the torque converter 8 is adjusted to the slip tm diagram shown in FIG. 11, for example. Control slip along. Figure 11 shows torque converter output shaft 1
4 and the throttle opening of the engine 10, that is, the target slip amount of the torque converter 18 to be achieved for each operating state of the engine 10, where the complete C/v
is the range in which the clutch 22 is completely deactivated and the torque converter 18 is in a converter state where the input/output elements 1-8a and 13b are not directly connected (slip amount is maximum), and power transmission is to be performed in the converter state (maximum slip amount). In this case, the clutch 22 is fully activated and the torque converter 13 is connected to the input/output element 1.
3a and tab are directly connected to each other in a lock-up state (zero slip amount), and in other regions, the clutch 22 is operated in a half-clutch state, and the slip of the torque converter 13 is controlled by adjusting the joint force. 2ORP the amount (relative rotation of input/output elements i3a and tab)
The slip range should be M, 40 RPM, and 60 RPM. As shown by the arrow in this figure, when the torque converter 13 enters the complete L/U region from the complete 0/V region or the slip region, the torque converter 13 generates the above-mentioned lock-up shock.
In order to make this sufficiently small, the present invention controls the torque converter as follows.

First, in step 51 of FIG. 8, the MPU 36
A torque converter output shaft rotational speed signal S is stored in the OM87 from table data corresponding to the slip amount diagram in FIG. Based on r and throttle opening signal STH,
It is determined whether the operating state is such that the torque converter 13 should be in the complete 0/V range. If so, control passes to step 52.
Here, the MPU&6 sets the output duty to 0%, and in the next step 55', resets a counter, which will be described later, to the count value MEO. With this duty of 0%, as is clear from FIG. 6, the lock-up pressure PL/u is equal to the converter pressure P. As a result of releasing the lock-up clutch 22, the torque converter 13 is brought into the converter state as required in the complete 0/V region in FIG. 11, and power can be transmitted in this state.

If it is not a complete C/v area, step 51 is step 5.
3 is selected, and here MPU 86 obtains the output shaft rotational speed signal S from the table data corresponding to the slip amount diagram in FIG. Based on r and throttle opening signal STH, it is determined whether the engine 10 is in an operating state in which the torque converter 18 should be in the full L/u range. Otherwise, if the engine 10 is in an operating state (slip region) in which the torque converter 18 should be subjected to slip control, control proceeds to step 54, where the MPU 86 executes a normal slip control program as described below. That is, first, the MPU 36 obtains the output shaft rotational speed signal S from the table data corresponding to the slip amount diagram in FIG. Based on r and throttle opening signal TH, target sling and pull amount 20 RPM
, 4 ORPM or 60 RPM using a table lookup method, and the slip amount of the torque converter 13 (input/output element i 3 a ).

The coupling force of the clutch 22 is controlled by the duty control G of the electromagnetic valve 29 via the amplifier 41 shown in FIG. 7 so that the relative rotation of the clutch 13b becomes the target slip amount. Thus, the torque converter 18 operates in the slip region shown in FIG. 11 for each operating state of the engine 10, that is, for each throttle opening and torque converter output shaft rotational speed (this target slip amount is 20 RPM).

The engine speed is maintained at 40 RPM or 60 RPM, and it is possible to operate with high power transmission efficiency while absorbing engine torque fluctuations in a slip state with just the right amount. After that, the control proceeds to step 55, where the MPU 86 resets the counter described later so that the count value M becomes O. By the way, from the above-mentioned complete 0/V region or slip region to a complete L as shown by the arrow in FIG. / When the operating state of the engine 10 changes to enter the u range, step 53
selects step 56, where the MPU 36 determines whether the count value N of the counter reset in step 55' or 55 is greater than or equal to the set value Mmax. This counter is incremented by 1 every time it is activated as described below, that is, every time the interrupt signal from the timer is inputted every 27 hours, and serves as a timer for setting the time for performing the lock-up control of the present invention. , the relevant time is ΔTXM
max is set to 0.However, due to the above reset, it is now the end. Since M=O, the control proceeds from step 56 to step 57, where the MPU 36 outputs the signals Sia, s
Based on or, calculate the actual rotational difference (torque converter slip amount) ΔN between the input and output elements by calculating 1 engine rotational speed (rotational speed of input element 13a) - output rotational speed (1 rotational speed of output element 18b, and then In step 58, it is determined whether M=0.

As mentioned above, since M=0 now, step 58 is followed by step 59-1.59-. 2.60 is sequentially selected, and in step 59-1, the slip amount (initial slip crucible ΔN) at the time of the lock-up command (M20) is read and set. In the next step 59-2, the initial slip amount Δ
Torque converter output shaft rotation speed at Ni and lockup command (initial torque converter output shaft rotation speed)
For each NIJ (read from signal S.r), a predetermined reduction rate of slip amount (limit value to make lock-up shock no longer a problem) Ai5 is determined from the table data set as shown in the following table and stored in ROM 371. is set using the table lookup method.

Table 1 1500200025003000 The initial torque converter output shaft rotational speed N1j (RPM) reduction rate A... should be small so that lock-up shock does not become a problem, but if it is too small, the lock-up response will deteriorate, so Determined based on the balance between And, as is clear from the above (Equation 11), Δ
Since the lock-a and the lump shock become larger as N□ and N□3 become larger, the table data should be determined so that the reduction rate A:Lj becomes smaller as ΔN increases and also becomes smaller as N I J increases. .

In the next step 60, the initial duty value Duty (OLD)i at the time of the lock-up command (M-0) is set, and the control proceeds to step 61.In step 61, the counter is operated and its count value M is incremented by one. Proceed,
As a result, M←0. After that, step 58 selects step 61, and the count value of the counter is simply incremented by one. Therefore, the lock-up control that will be performed from now on will be based on the slip amount. In other words, in step 62, from the initial slip amount ΔNi and the count value M, ΔN - Aij After determining the slip amount ΔN", step 57 is performed in the next step 63.
The deviation ΔX between the measured slip amount ΔN and the target slip amount ΔN7 is calculated.

Next, the control proceeds to step 64, where it is determined whether the deviation ΔX is greater than 0, that is, whether the torque converter 18 is slipping too much with respect to the target slip amount ΔN0. If so, step 65 is selected, where Duty (NE W )=Duty (OLD
) Perform a calculation in the direction of increasing the output duty by 1/10 ΔX, and use the calculation result Duty (NEW) in the next step 6.
At step 6, the output duty is replaced with Duty (OLD), and then at step 67, Duty (NEW) is outputted as an output duty to the solenoid valve solenoid 29b via the amplifier 41 in FIG.

Here, Duty (N E W ) is the output duty to be newly updated, Duty (OL D ) is the current output duty, and K is a proportional constant, so the above control changes the output duty by the constant K according to the deviation ΔX. It increases by an amount proportional to Q. As is clear from Fig. 6, due to this increase in output utility, the lock-up pressure "L"
/u is reduced, the clutch 22 in FIG. 2 strengthens the coupling force, corrects the above-mentioned excessive slip of the torque converter, and makes it possible to bring the slip ht closer to the target value ΔN''.

On the other hand, if the determination result in step 64 is not ΔX>0,
In other words, if the torque converter 18 has insufficient slip with respect to the target slip amount ΔN", the control proceeds from step 64 to step 68. Here, puty (N E W
) = Duty (OLD) - K - ΔX in the direction of decreasing the output duty, and the calculation result Duty (NEW) is used in the next step 66゜67
As mentioned above, the output duty is 0, which is output to the solenoid valve solenoid 29b. Therefore, the output duty is the deviation Δ
According to X, it will decrease by an amount proportional to the constant K,
As a result, as is clear from Fig. 6, the lock-up pressure PL
/u is increased, the clutch 22 in FIG. 2 weakens the coupling force, corrects the lack of slip in the torque converter, and brings the amount of slip closer to the target value ΔN''.

The above control program is repeated by an interrupt signal from the timer at every ΔT time interval, and the torque converter 1
The slip amount ΔN of No. 3 is controlled stepwise to become the target slip amount ΔN" corrected at every ΔT time interval, and gradually decreases at a predetermined ratio Aij, and finally becomes zero. In other words, the lock-up command It is clear from FIGS. 9 and 10, which show the lock-up control modes when the initial slip amount ΔNi is the same but the initial torque converter output shaft rotational speed N0 is low (N1j') and high (N1j''), respectively. As shown, after the lock-up command instant t, the slip amount ΔN of the torque converter 18 is gradually reduced to zero in accordance with the target slip amount ΔN, and the lock-up is performed by changing the output duty to obtain this slip amount change. By the way, in the present invention, as is clear from the comparison between FIGS. 9 and 10, N'<N
1j''J (the same applies even when ΔNi is different). During the lock-up control shown in FIG. 9 where the lock-up shock is small, the decreasing rate of the slip amount ΔN is made small, and during the lock-up control shown in FIG. 10 where the lock-up shock is large, the slip amount ΔN is reduced. (by varying the ratio A ij ), in both cases the lock-up pressure P is
As shown in Figures 1 and 2, the tension can be maintained at approximately 7 lats during the instants t2 to t8 from when the clutch 22 starts to engage until it ends. Therefore, the torque waveform of the torque converter output shaft only produces minute peak torques β□, β2 near instant t8 in any case, and lock-up shock can be reliably reduced at all times. In addition, since the ratio A is appropriately selected for each operating state, the lock-up shock reduction effect described above can be achieved without unnecessarily reducing the rate of decrease of the slip amount ΔN by Q, and the lock-up is delayed in the operating state. There are no problems such as poor engine fuel efficiency.

When the lock-up control of the present invention is completed, an instant t
At the instant t4 at which the set time ΔTXMmax has elapsed, the determination result in step 56 becomes M>Mmax, and the control then proceeds to step 69. In this step, the duty is set to 100%, and as a result of supplying this to the solenoid valve solenoid 29b, the lock-up pressure P is minimized as shown in FIG. / A lock-up state can be maintained as required in the u region. In the above embodiment, the ratio Ai-J is set as above based on the initial slip amount ΔNi and the initial torque converter output shaft rotation speed N1j, which determine the magnitude of the hook-up shock. Although set at the beginning of Table 1, the ratio Aij can be set based on other data that determines these ΔNi and N1j. That is,
For example, as shown in FIG.
r, the relationship is established, the torque converter slip amount corresponds to the combination of engine speed and throttle opening, and the torque converter output shaft speed is the difference between the engine speed and the torque converter slip amount, which is completely 0. Therefore, the ratio Ai
j can also be set as shown in the following table based on the initial throttle opening and initial rotational speed of the engine at the time of the lock-up command.

Table 2 1500 2000 2500 8000 Initial engine rotation speed (RPM) For the same reason, the initial torque converter output shaft rotation speed in Table 1 above is replaced with the engine rotation speed, and the ratio A is calculated based on this and the initial slip amount. It goes without saying that it is also possible to set ij, or replace the initial engine speed in Table 2 above with the initial torque converter output shaft speed, and set the ratio Aij based on this and the initial throttle opening. stomach.

Effects of the Invention Thus, as described above, the lock-up control device of the present invention controls the relative rotational speed (initial slip amount ΔNi) of the input/output elements 18a and 13b and the output element 13 at the time of the lock-up command.
b rotation speed (initial torque converter output shaft rotation speed NIJ
), the operation of the clutch z2 is feedback-controlled so that the torque converter slip amount ΔN gradually decreases to zero to bring the torque converter 13 from the slip state to the lock-up state at a ratio AiJ corresponding to ΔNi and N1j, which are involved in the magnitude of lock-up shock, can be adjusted at all times, and lock-up shock can be prevented under any driving conditions without deteriorating fuel efficiency or wearing out the facings of the clutch 22 due to a delay in lock-up response. This can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing the device of the present invention, FIG. 2 is a system diagram showing an embodiment of the device of the present invention, and FIG.
Figure 4 is a change characteristic diagram of control pressure with respect to duty, and Figures 5 (a) and (1)) are slip control valves. Fig. 6 is a change characteristic diagram of lock-up pressure with respect to duty, Fig. 7 is a plot line diagram of the slip control fan unit, Fig. 8 is a flowchart showing the control program of the slip control computer, Fig. 9 and 10 are operation time charts showing two operation modes of the device of the present invention depending on the rotational speed of the torque converter output shaft, respectively. FIG. 11 is a control pattern diagram of the torque converter, and FIG.
13 and 14 are diagrams showing how the torque converter slip ratio changes depending on the operating condition of the engine, and FIGS. 9 and 10 show two operating modes of the lock-up control device previously proposed by the applicant. FIG. 15 is an operation time chart similar to the one shown in the figure, and FIG. 15 is an operation time chart of a conventional lock-up control device. 1 - Power source 2... Torque converter input element 3 - Torque converter output element 4... Clutch 5 - Lockup determination means 6 - Slip amount detection means 7... Clutch control means 10 - Engine (power source) 11...・Crankshaft 12... Flywheel J3 ・Torque converter 18a... Doujinshi element (pump impeller) 13b...
Output element (turbine runner) 14... Torque converter output shaft 22... Clutch (lock-up clutch) 24... Lock-up chamber 25... Slip control valve 28... Control pressure generation circuit 29... Solenoid valve 31 ... Slip control computer 88 ... Engine speed sensor 84 ... Torque converter output speed sensor 35 ... Engine throttle opening sensor 36 ... Microprocessor unit 37 ... Read-only memory 38 ... Human output interface Circuit 89...A/D converter 40 -Waveform shaping circuit 41...Amplifier -T (%) Figure 5 (a) (b) Figure 6 (%) Figure 9 Figure 1θ Figure 11 Number of corridors (RPM) 12th
Figure 1000 2000 3000 Eng/i7 times! @Dazzle (RPM) Figure 13 Figure 14

Claims (1)

[Scope of Claims] L An input element driven by a power source and an output element driven by hydraulic oil stirred by the input element, and the relative rotation between the input and output elements is zero by appropriate operation of a clutch. A lock-up determining means for determining whether or not the power source is in an operating state that requires lock-up by actuation of the latch, and a relative rotation between the input and output elements. Upon receiving a lock-up command from a slip liquid detection means and a lock-up determination means, the slip liquid detection means detects the number of slips, and upon receiving a lock-up command from the lock-up determination means, the relative @
1. A lock-up control device for a torque converter, comprising clutch control means for feedback-controlling the operation of the clutch so as to gradually reduce the rotation speed to zero. 2. The clutch control means controls a ratio corresponding to the relative rotational speed and the output element rotational speed at the time of the lock-up command,
The lock-up control device for a torque converter according to claim 1, wherein the lock-up control device for a torque converter is indirectly determined based on the load and rotation speed of the power source. & The clutch control means indirectly determines a ratio corresponding to the relative rotational speed and the output element rotational speed at the time of the lock-up command based on the load of the power source and the output element rotational speed. A lock-up control device for a torque converter according to item 1. The clutch control means sets the ratio corresponding to the relative rotational speed and the output element rotational speed at F at the time of the lock-up command.
The lock-up control device for a torque converter according to claim 1, wherein the lock-up control device for a torque converter is determined based on the relative rotation speed and the power source rotation speed.