JPS6267362A - Slip control device for torque converter - Google Patents

Abstract

PURPOSE:To decrease a slip rate as an output speed increases while to increase the slip rate as a throttle opening increases in a slip region, by providing a pressure regulating valve and controlling the pressure in a converter chamber to a fixed value or to be decreased as an engine load increases. CONSTITUTION:A converter pressure Pc is held to a fixed value by a pressure regulating valve, and a lockup clutch, generating no change of its transmission torque TL due to an engine load, determines said torque unconditionally by turbine torque TT because a lockup control pressure PL is determined by the turbine torque (variable orifice opening). Accordingly, when engine torque TE, shown by a sum of the turbine torque TT and the clutch transmission torque TL, is, for instance, 14, 10, 6kg.m, a converter obtains control points C, D, E while the turbine torque T1', T2', T3' in the drawing. And being the turbine torque in a relation where T1'>T2'>T3', when the same output rotary speed is generated, a slip amount is controlled so as to increase larger as the engine load increases.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a torque converter, and particularly to a slip control device for a lock-up torque converter that can appropriately limit relative rotation (slip) between input and output elements.

(Prior art) A lock-up torque converter is equipped with a lock-up clutch between input and output elements, and the coupling (including sliding coupling) can limit slip, eliminating unnecessary slip and improving the power transmission efficiency of the torque converter. can be improved.

Conventionally, slip control devices for lock-up torque converters have been disclosed in Japanese Patent Publication No. 59-747, U.S. Pat.
The one described in Japanese Patent No. 1567 is known.

This slip control device has a variable orifice whose opening degree changes depending on the transmitted torque of the torque converter output element, and pressure flows from the converter chamber on one side of the lock-up clutch to the lock-up control chamber on the other side through the variable orifice. The slip control is performed by determining the differential pressure (coupling force of the lock-up clutch) between the convergence pressure in the converter chamber and the lock-up control pressure in the lock amplifier control chamber.

(Problem to be Solved by the Invention) However, in such a conventional slip control device, the converter pressure in the converter chamber is controlled by a normal non-lock-up type).+
b'r゛-v 2y・(-Since it is supplied in the same way as before, this one inverter pressure will rise as shown in Fig. 12 if the throttle opening (engine load) increases +゛, 7 i, fPjt Therefore, the slip characteristics do not occur in the bar--even region as shown in Fig. 13 (e = o).
In the slip region between the lock-up region and the lock-up region, the slip ratio e can be changed in puffs, and this slip ratio e becomes smaller as the torque converter output rotational speed increases, and also becomes smaller as the throttle opening increases.

However, the ideal slip characteristic is as shown in FIG. 14, and the slip ratio e needs to decrease as the torque converter output rotational speed increases, and increase as the throttle opening increases.

In comparison with such ideal characteristics, in the conventional slip characteristics, the change in slip ratio e with respect to throttle opening is opposite to the ideal, and for example, slip restriction is insufficient at low engine load (low throttle opening). Problems have arisen, such as not being able to achieve the desired fuel efficiency improvement effect and premature wear of the lock-up clutch.

Next, when the converter pressure increases as the throttle opening increases as described above (see Figure 12), the slip characteristic
The first reason why the image is as shown in the figure will be explained.

FIG. 15 shows the change characteristics of converter pressure and lock-up control pressure with respect to the variable orifice opening degree (torque converter output element transmission torque), in which the variable orifice is fully opened when the torque converter output element transmission torque is 0,
When this torque is 2 kg-m, it becomes fully open. PCL is the converter pressure at low throttle opening, and as the variable orifice opening increases under this throttle opening, the lock-up control pressure decreases like PLL, and due to the force according to the difference between these pressures PCL - PLL. A lock-up clutch is engaged to limit slip. Also P. H is the converter pressure at a high throttle opening, and as the variable orifice opening increases under this throttle opening, the lock-up control pressure decreases as PLH (7, the force corresponding to the difference between these pressures PC1t PLH4) Due to lock nabu pukura:!chi is combined to limit slip.

The transmission torque of the lock-up clutch, which is proportional to the pressure difference shown in L, is proportional to the transmission torque of the torque converter pressure element as shown in FIG. is T in Figure 16
Like LL, and when the throttle opening is high, TLI (
It changes like this. Furthermore, the engine output torque T, which is expressed as the sum of the torque converter output element transmission torque and the lock-up clutch transmission torque, is 6.0 kg-m corresponding to the low throttle opening mentioned above, and at the high throttle opening indicated by L. An example of the case of 12.0 kg-m corresponding to the opening degree is shown in FIG. Therefore, the slip control point at the above-mentioned high throttle opening is between the line TL□ and T E = 1
This is the intersection point A with the 2.0 kg・m line, and the slip control point at the above low throttle opening is TLL and TE = 6.0
kg-m line, and T at these control points.

The slip is controlled so that -T1 (at high throttle opening) and T2 (at low throttle opening).

By the way, T, l > T, and as is clear from this, for the same torque converter output shaft rotation speed, the amount of slip is controlled to be smaller when the throttle opening is high than when the throttle opening is low. .

Therefore, as mentioned above, in the conventional slip control device,
The change in the slip ratio with respect to the throttle opening (engine load) is opposite to the ideal, resulting in the above-mentioned problem.

In order to solve this problem, the present invention provides a slip control device of the above type in which the converter pressure in the converter chamber is kept at a constant level.
It is equipped with a pressure regulating means that maintains the pressure directly or decreases it as the engine load increases.

(Function) The variable orifice changes its opening according to the transmitted torque of the torque converter output element, and controls the pressure flowing from the converter chamber on one side of the lock-up clutch to the lock-up control chamber on the other side according to the opening degree. Determine the lockup control pressure in the lockup control chamber. The lock-up clutch is engaged with a force corresponding to the differential pressure between the lock-up control pressure and the converter pressure in the converter chamber, and controls relative rotation (slip) between input and output elements of the converter.

By the way, during this time, the pressure regulating means maintains the converter pressure at a constant value, or lowers the F as the engine load increases.
It is possible to solve the above-mentioned problem that occurred due to the converter pressure rising as the engine load increases, and it is possible to make the change in slip ratio with respect to the engine load have the same tendency as the ideal characteristic. . Therefore, problems such as failure to achieve the desired fuel efficiency improvement effect due to insufficient slip restriction at low engine loads and premature wear of the lock-up clutch are avoided.

(Example) - Hereinafter, the present invention will be described in detail based on illustrated embodiments.

Figure 1 shows an embodiment of the slip control device of the present invention.
shows a lock-up torque converter to be subjected to slip control by this device, which is mainly composed of a pump impeller (torque converter manual element) 2, a turbine runner (torque converter output element) 3, and a stake 4.

The pump impeller 2 is welded thereto and drive-coupled to an engine crankshaft (not shown) via a converter cover 5, so that it is constantly driven by this during engine operation. A hollow pump drive shaft 6 is further welded to the pump impeller 2, and a pump (not shown) for generating line pressure P to the pressure regulating valve 7 is constantly driven by this shaft during engine operation. .

The turbine runner 3 has a turbine hub 9 riveted to its inner circumferential edge by a rivet 8, through which the turbine runner 3 is rotatably fitted onto a sleeve 10. 1. A spline connection is made to the torque converter output shaft 11 so that it does not move in the axial direction and becomes a part of the output shaft 11. flanges 9a, 1 extending radially outwardly towards each other on the turbine bald 9 and the sleeve 10, respectively;
0a), and an annular plate 12 is disposed on one side of the flange 10a opposite to the seventh flange 9a. 7. The flange 9a and the annular plate 12 are integrally connected by the butt 13.
The rivet 13 is loosely inserted into the corresponding hole 10c of the 7 flange IDa to allow relative rotation between the 7 flange 9a and loa, and therefore between the turbine hub 9 and the three 110.

Outer springs 14 and inner springs 15 provided inside the outer springs 14 and inner springs 15 are arranged in alignment windows provided in the flanges 9a, 10a and the annular plate 12, respectively, in the circumferential direction of the flanges 9a, 10a and the annular plate 12, and these springs 14. A lock-up clutch 16 is provided on the sleeve 10 (6). are slidably fitted,
When the lock-rub clutch 16 presses its outer circumferential tarlatch fading 16a against the converter cover 5, a lock-up control chamber 18 isolated from the converter chamber 17 is created between the two. Lockup control room 18
are the holes 10b and slits 10d formed in the sleeve]0.
1. A hole 9b provided in the turbine hub 9 communicates with the converter chamber 17, and the hole 9b and slit 10d have an opening degree S indicated by diagonal lines in FIG. 2 depending on their overlapping amount.
The variable orifice 19 is configured to change the degree of communication between the convergence chamber 17 and the lockup control chamber 18 according to its opening degree.

An annular member 20 having an L-shaped cross section is further fixed to the lock-up clutch 16, and teeth 20a formed on the free end edge of the annular member 20 are engaged with teeth 10e formed on the outer peripheral edge of the flange 10a. sleeve 10
The drive is coupled to allow relative axial movement.

The stator 4 of the torque converter 1 is placed on a hollow fixed shaft 22 via a one-way clutch 21, and
2 and the pump drive shaft 6 and the torque converter output shaft 11, annular passages 23, 24 are provided, respectively.

The annular passage 23 converts the line pressure P generated by the oil pump into the torque converter 1 under pressure regulation by the pressure regulating valve 7.
The hydraulic oil is introduced into the converter chamber 17 and removed from the annular passage 24, but in combination with a pressure holding valve (not shown) provided in the subsequent hydraulic oil passage, the pressure regulating valve 7 is \
, '7 chamber] 7 internal dimension Te ~ constant converter pressure P. Keep it.

For this purpose, the pressure regulating valve 7 as pressure regulating means is a constant pressure valve as described below. That is, the spool 7a is biased to the left in the drawing by a spring 7h, and the pressure inside the chamber 7C causes the spool 7a to move to the right in the drawing against the spring 7b. Then, the spool 7a is in the neutral position shown, cutting off the output port 'I'd from both the human capo) 7e and the drainboard) 7f. In the middle right row, port 7d is connected to port 7f. Output capo) 7f is feedback passage 7g
It is connected to the chamber 7C and also to the passage 23, and supplies the line pressure P to the bow 7e.

In the pressure regulating valve 7, the spool 7a is normally set at the left limit position, the port 7d is connected to the bow) 7e, and the line pressure P1 is supplied to the port 7d. As a result of this, the output pressure from bow) 7d increases, and the spool 7a receives this output pressure in the chamber 7c, and is moved to the right in the figure. The output pressure of spring 76 is
When the value corresponding to the spring force b is reached, the spool 7a
is at the pressure regulating position shown in the figure, and the output pressure is stopped from rising. Thus, the pressure regulating valve 7 maintains the output pressure from the bow) 7d, that is, the converter pressure P. can be maintained at a constant value determined by the spring force of the spring 7b.

Further, the lockup control chamber 18 communicates with the communication port 25a of the lockup control valve 25 through the hollow hole 11a of the torque converter output shaft 11, and this control valve is connected to the spool 25.
b. Plug 25c1. Consists of springs 25d and 25e that bias these toward the right in the figure. Lockup control valve 25
is the spool 25tl in response to the governor pressure P0 equivalent to the vehicle speed (torque converter output shaft rotation speed) supplied to the chamber 25f.
'c1!' in the chamber 18 for each converter region, slip region, and lockup region by selectively communicating the communication port 25a with the inlet port 25g, the drain port 25h with a fixed orifice 26, or the drain port 251.
The function is to control the backup control pressure P, and the population port
) For 25g, the converter Pc is introduced.

The operation of the lock-up torque converter equipped with the slip control device of the present invention configured as described above will now be described.

When the vehicle speed is in the low converter range (see Fig. 8), the corresponding gutter pressure P. pushes the spool 25b against the spring 25d, and the lock-up control valve 25 maintains the state shown in FIGS. 1 and 4. In this case, converter pressure P.

is supplied to the lock-up control chamber 18 through the bow) 25g, 25a and the hollow hole 11a, and the lock-up control pressure Pt in this chamber Maintain the release position shown and operate the lock-up torque converter in the converter state. That is, the engine-driven pump impeller 2 directs hydraulic oil to the turbine runner 3, which then returns to the pump impeller 2 via the stator 4.

During this time, the hydraulic oil rotates the turbine runner 3 with increasing torque under the reaction force of the stator 4, and this rotational power is transferred to the turbine hub 9, spring 14, etc. 15 and sleeve 1
0 and can be taken out from the torque converter output shaft 11.

On the other hand, when the vehicle speed is in the lock-up region (see Figure 8)
, a correspondingly high governor pressure P can push the spool 25b not only against the spring 25d but also against the spring 25e, and the lock-up control valve 25 is in the state shown in FIG. Become. In this case, the lockup control room 18
℃】Tsukua・7・P control pressure P.

is the hollow hole 11a1 port 25a and drain port) 25h
) 25i and is maintained in an unpressurized state, the lock-up clutch 16 is moved to the left in FIG. Operate the torque converter in lock-up condition. That is,
The engine rotation toward the pump impeller 2 does not pass through the torque converter 1, but passes through the lock-up clutch, the chi 16, the annular member 20, and the sleeve 10, and is taken out from the torque converter output shaft 11 as it is, so that the slip ratio e of the torque converter becomes zero. It can be done.

When the vehicle speed is in the slip region between the above two values (see FIG. 8), the corresponding governor pressure P is determined.

This brings the lock-up control valve 25 into the state shown in FIG.

In this case, the pressure PL in the lock-up control chamber 18 is extracted through the fixed orifice 26, while the pressure PL in the lock-up control chamber 18 is extracted through the variable orifice 1
Pressure P from the converter chamber 17 via 9.

receive replenishment. Thus, this frontage ivy up control room 1
The pressure PL in the variable orifice 19 is determined by the opening degree S of the variable orifice 19, and the lock-up clutch 16 is frictionally coupled to the converter cover 5 while slipping at a degree corresponding to this pressure P, and the converter state, lock-up state, and intermediate state are established. (slip control state) to transmit power.

Here, considering the change characteristics of lock-up control pressure P, converter pressure P. is maintained at a constant value as shown in FIG. 6 by the pressure regulating valve 7, so the lock-up control pressure PL
As shown in the figure, the variable orifice 19 changes with a characteristic uniquely determined by the opening degree of the variable orifice 19, that is, the transmission torque (turbine torque) of the turbine runner 3, and does not change depending on the engine load.

Therefore, as shown in FIG. 7, the transmission torque TL of the lock-up clutch 16 does not vary depending on the engine load, but changes with characteristics uniquely determined by the turbine torque. Therefore, when the engine output torque TE is 14 kg-m (at high engine load), and when the engine output torque TE is 10 kg-m,
m (at medium engine load) and at 6.0 kg-m (
(at low engine load), the respective control points are C, D, and E, and the turbine torque is T I ' +
T2' + T3', becomes. and,
Since T, '> T2 '> T, ', when the torque converter output shaft rotation speed is the same, the slip amount is controlled to increase as the engine load increases. Therefore, the change in the slip ratio with respect to the engine load has the same tendency as the ideal, and the slip characteristics in the slip region can be made as shown by the solid line in FIG. 8, making it possible to approach the ideal characteristics shown in FIG. 14.

FIG. 9 shows another example of the present invention. In this example, the pressure regulating means 7 is not a constant pressure valve as in the previous embodiment, but a land 71 with a smaller diameter is provided coaxially with the ride 7h of the spool 7b which is far from the spring 7b. The configuration is such that the chamber 7j is set by integrally providing the chamber 7j.
A throttle pressure PT)I proportional to the throttle opening (engine load) is supplied to the engine.

In this case, the spool 7a applies the throttle pressure PT to the chamber 7]
□ applies a force to the right in the figure, and since this throttle pressure is proportional to the throttle opening, the pressure regulating valve 7 maintains the converter pressure P. is decreased as the throttle opening (engine load) increases as shown in FIG.

Therefore, as shown in FIG. 11, the transmission torque TL of the lock-up clutch 16 is the turbine torque T.

On the other hand, when the throttle opening is low, it changes like TLL', and when the throttle opening is high, it changes like T, □', and it is larger when the throttle opening is low than when it is high. Therefore, high throttle opening (engine output torque TE = 14
．． The Kel turbine torque T'r = T1' at the control point F at the time of 0 kg-m) is the turbine torque T'r at the control point G at the low throttle opening (engine output torque T = =6.0 kg-m). = T3', and as is clear from this, in the case of the same torque converter output shaft rotational speed, the slip margin is controlled to increase as the throttle opening becomes higher (higher engine load). Therefore, in this case as well, the change in the slip ratio with respect to the engine load has the same tendency as the ideal, and moreover, in this example, the slip ratio changes with respect to the engine load.
As can be seen by comparing the figure with Fig. 7, the range of T, f - T3' is wider than the range of T, / - T3', so the slip characteristics of the slip region are shown by the dotted line in Fig. 8. The characteristics can be brought even closer to the ideal characteristics shown in FIG. 14.

(Effects of the Invention) Thus, as described above, the slip control device of the present invention is provided with the pressure regulating means 7 to adjust the converter pressure P in the convergence chamber 17. Since the configuration is such that the slip ratio is maintained at a constant value (the first embodiment) or is decreased as the engine load (in the illustrated example, the throttle pressure PTI( For example, the slip restriction at low engine load is insufficient and the fuel efficiency improvement effect of 1 cannot be achieved as specified.
Problems such as premature wear of the lock-up clutch 16 will not occur.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional side view of a torque converter equipped with the slip control device of the present invention, Fig. 2 is an explanatory diagram showing the variable orifice as viewed from the ■ arrow in Fig. 1, and Figs. 3 to 5 are lock-up control valves. FIG. 6 is a change characteristic diagram of converter pressure and lock-up control pressure in the lock-up control device shown in FIG. 1, FIG. 7 is a relationship diagram between turbine torque and lock-up clutch transmission torque in the same device, Fig. 8 is a diagram showing the slip characteristics of the same device and the device of Fig. 9, Fig. 9 is a sectional view of a pressure regulating valve showing another example of the device of the present invention, and Fig. 10 is a converter using the device of Fig. 9. Figure 11 is a graph showing the relationship between turbine torque and lock-up clutch transmission torque in the same device, Figure 12 is a graph showing converter pressure changes in the conventional device, and Figure 13 is the slip characteristic in the conventional device. Fig. 14 is a diagram showing ideal slip characteristics, Fig. 15 is a graph showing changes in converter pressure and lock-up control pressure in a conventional device, and Fig. 16 is a diagram showing torque converter output element transmission in a conventional device. FIG. 3 is a relationship diagram between torque and lock-up clutch transmission torque. 1...Torque converter 2...Pump impeller (torque converter human power element)
3...Turbine runner (torque converter output element)
4... Converter cover 7... Pressure regulating valve (pressure regulating means) 9... Turbine hub 9a... Hub flange 9b
...hole 10...sleeve 10a...
・Sleeve flange 10b, lOc...4-L 10d...
Slit 10e... Teeth 11... Torque comparator v output shaft 12... Annular plate 1309. Rivet 14.
15... Spring 16... Lock-up clutch 17... Converter chamber 18... Lock-up control chamber 19... Variable orifice 20... Annular member 20a... Teeth 21...
One-way clutch 22...Hollow solid shaft 25...Lock-up control valve 26...Fixed orifice S...Variable orifice opening Fig. 3 Fig. 4 Fig. 5 Fig. 6 Turbine torque K)・m (Variable profile M1 Fig. 9 Fig. 1 O Fig. ku 0.7 Torr degree (〃) Slow 7 Torr opening degree (%) 017F・y7”) Ra y + Ifit) / F to L hole 7L
・K2 Comparg pressure (1'>/Cyn") Lock?Tsugwot + Stretch iF Lug(-do i-τ Throttle relation (%2 0・Nquat 7゛Grats nice i)-/Ref(now So filtration pressure (ni'2-/c constant 22

Claims (1)

[Claims] 1. A lock-up clutch capable of appropriately restricting the relative rotation between the torque converter input and output elements, and a variable orifice whose opening degree changes according to the transmission torque of the torque converter output element, and the lock-up clutch passes through the variable orifice. In the torque converter, the degree of restriction of the relative rotation is controlled by determining the coupling force of the lock-up clutch according to the pressure flowing from the converter chamber on one side to the lock-up control chamber on the other side, wherein the converter pressure in the converter chamber is 1. A slip control device for a torque converter, characterized in that the slip control device for a torque converter is provided with a pressure regulating means that maintains the pressure at a constant value or decreases the pressure as the engine load increases.